The glossary
Access business ; BT's business containing all the income, costs and assets and liabilities associated with providing connections, take-over and maintenance of exchange lines.
Access Code ; short numbers beginning with 1 which enable callers to reach services provided on telecoms networks (e.g 192 for directory enquiries) or to select a choice of carrier.
Access Control Services ; are required by service providers in order to be able to offer services through conditional access systems operated by third parties.
Access control services ; the services which third parties require in order to use the system to offer interactive services.
Accounting arrangements ; Agreements made between two international operators at each end of a particular route for the handling of international calls. They include arrangements for each operator to pay the other for the termination of calls in their respective countries.
Accounting Rate ; the per-minute charge agreed by the two parties at each end of an international route at which traffic will be charged. Denominated in SDRs.
Accounting Separation ; the preparation of separate accounts for different businesses and parts of businesses run by the same company or group of companies, so that the costs and revenues associated with each business and part of a business (and transfers between them) can be separately identified and properly allocated.
ACTE - see Approval Committee for Terminal Equipment
ACTs - Advisory Committees on Telecommunications.
ADSL - see Asymmetric Digital Subscriber Line
Advance contract package ; A package which includes the phone, connection, a year’s line rental and, in some cases, some inclusive call minutes.
Allocation to end users - telephone numbering capacity is currently allocated in blocks (eg of 10,000 numbers) to network operators. For certain types of numbers, including freephone numbers, OFTEL intend to move away from this system in due course to one where numbers are allocated directly to the user by a central administration body. This means that, instead of approaching an operator for the number, the customer will obtain it from the central administration body. The customer would then approach the network operator of their choice in order to have service provided on that number.
Amortisation ; the recovery of a capital cost through a number of periodic payments.
Analogue - the direct representation of a waveform, as opposed to digital which is a coded representation.
Analogue mobile -the original cellular systems of the type used by Vodafone and Cellnet ie Total Access Communications System (TACS) and Extended Total Access Communications System (ETACS).
Annex II (of the ICD) - annex II operators are those who have rights and obligations to interconnect with each other under Article 4(1) of the Interconnection Directive for the purpose of providing publicly available telecommunication services.
Anonymous call rejection ; a service which prevents calls from being connected or put through where a caller has withheld CLI
Approval Committee for Terminal Equipment (ACTE) - an advisory body to the European Commission on the implementation of the Telecommunications Terminal Equipment Directive. It gives general guidance on the application of the Directive, and has the formal responsibility of adopting Common Technical Regulations which are binding on all member states.
Application Programme Interface (API) ; software in the receiver which interprets a set of commands telling it, for instance, where to display a graphic or other object on the screen. The API also allows the same applications to run on different receiver designs without the need for the application to be rewritten for each one.
Arbitrage ; the ability to buy for one price and sell on for a higher price.
Asymmetric Digital Subscriber Line (ADSL) - (also known as xDSL) a technology that allows the use of a copper line to send a large quantity of data (eg a television picture) in one direction and a small quantity (eg a control channel and a telephone call) in the other..
ATM - Asynchronous Transfer Mode ; the internationally agreed basis for broadband ISDN. A technology that enables all types of information (data, voice and video in any combination) to be transported by a single network infrastructure.
AUC ; Authentication Centre*
AUCS - AT&T - Unisource
Autodiallers ; smart boxes installed at the customer's home which automatically dial the prefix to route calls to the selected CPS operator.
Average costs – the total cost of production of averaged over the quantity produced.
B7 ; a modern signalling system, based on standards set by the CCITT (the former name of the world telecommunications standards-making body), for the transfer of messages between entities in telecommunications networks that enables the setting up, routing and clearing of calls and the transfer of other relevant information related to the operation of these networks. The B7 signalling system is used for the transfer of such messages between different networks as well as within individual networks
BABT -British Approvals Board for Telecommunications.
Backhaul ; the link from the cablehead to (usually) the International Switching Centre
Bandwidth ; the physical characteristic of a telecommunications system that indicates the speed at which information can be transferred. In analogue systems, it is measured in cycles per second (Hertz) and in digital systems in binary bits per second. (Bit/s).
Barriers to Entry ; an additional cost which must be borne by entrants but not by firms already in the industry; or other factors, which enable an incumbent to maintain prices above the competitive level without inducing entry.
Basic channels - traditionally these were the channels which all TV subscribers received as part of the basic package. The term is increasingly being used to describe non-premium channels,. These are predominantly general news and entertainment channels. See also premium channels
Basic frame relay ; a packet data communications service providing a signalling and data transfer mechanism between endpoints of the public network. Frames are routed by the network on permanent virtual circuits according to address information embedded in the frames.
Basic SMDS ; a high-speed connecitonless data service which provides access to BT’s SMDS network, currently at access class rates up to 25Mbit/s.
Basic X.25 ; a layer 3 packet data communications service which provides access to an X.25 public switched network where the access circuit is a permanent or continuous link to the network from the customer’s premises.
Bearer Services ; Telecommunication services which give the user the capacity needed to transmit appropriate signals between certain access points.
Beta ; the co-efficient which measures the degree of correlation between the returns on shares in a particular company and returns on the stock market as a whole. In the Capital Asset Pricing Model, the higher a firm’s Beta, the greater the systematic riskiness of an investment in that firm’s shares (a Beta coefficient of one implying that the firm is of average risk).
Bonus channel ; a channel which is given away free to subscribers to a premium service or services
Bottom-up approach (to modelling of costs) ; the calculation of costs by identifying and summarising the costs of the items of equipment, manpower and other resources required. Contrasts with top-down approach, which involves removing from a known total the costs which are not relevant to the activity in question.
BRI - Basic Rate Interface
Broadband – a service or connection allowing a considerable amount of information to be conveyed, such as television pictures. Generally defined as a bandwidth > 2Mbit/s
Broadband Cable licence ; a licence that authorises the installation of an applicable cabled telecommunications system to convey messages comprising entertainment services and specified public telecommunications services within a specified area. Due to changes in the Broadcasting Act licensing regime this type of licence has not been issued since 1994.
Broadband Switched Mass Market Services - services aimed at a mass market delivered over broadband switched telecoms networks.
BSC ; Base Station Controller*
BSI - British Standards Institute.
BSS ; Base Station System*
BT - British Telecommunications plc.
BT's Licence - the licence granted to BT on 22 June 1984.
BT’s Network Business - The business containing all the costs, assets and liabilities of that part of the Systems’ Business relating to standard services provided to other operators or similar services provided to BT Retail and BT’s Retail Systems’ Business. A full description is provided in the Accounting Documents.
BT’s Retail Systems’ Business - The business containing all the costs and assets which are comprised in the Systems’ Business which are not comprised in the Access Business or the Network Business. A full description is provided in the Accounting Documents.
BTS ; Base Transceiver Station*
BT Chargecard ; BT service allowing customers to bill calls from any telephone to their home telephone bill or credit card.
BT Resellers' Licence ; the copyright licence BT issues for use of its Phone Base product to service providers and independent service providers using Phone Base to provide a service to end customers.
Bundling ; the tying of one service or product to the supply of others including some situations where the supply of services are linked through the use of discounts. See also full- line forcing
Buy-through restriction ; the restriction of the sale of premium channels to TV subscribers who have already purchased a basic tier of services. Buy-through restrictions may either refer to restrictions applied by the wholesaler to other retailers governing how premium channels may be resold, and to restrictions applied by retailers governing how customers may purchase these channels
C7 ; a modern signalling system, based on standards set by the CCITT (the former name of the world telecommunications standards-making body), for the transfer of messages between entities in telecommunications networks that enables the setting up, routing and clearing of calls and the transfer of other relevant information related to the operation of these networks. The C7 signalling system is used for the transfer of such messages between different networks as well as within individual networks.
Cable capacity ; The capacity an international cable has for carrying calls. Cable capacity can be expressed in terms of design capacity (the amount of capacity a cable is technically designed to carry) and notional capacity (the amount of capacity that has been subscribed for by cable consortia members).
Cable consortium ; a group of companies or organisations which club together to build an international cable.
Cablehead ; the point at which the international cable arrives and terminates. Also known as cable landing station
Cable landing station ; see Cablehead
Cable PTOs - the companies licensed to provide telephony and broadcast television services within exclusive, local franchises in the UK.
Cable station/cable landing station ; The point at which international submarine cables arrive and terminate. The point where the submarine cable is connected to the backhaul circuit.
Call barring ; specified numbers or ranges which cannot be dialled
Call charge advice ; cost of call can be obtained at the end of a call
Call completion ; a directory enquiry service which directly connects the enquirer to the number they seek. A call completion service without number disclosure directly connects the enquirer without revealing the number.
Call diversion ; call is re-routed to another number
Call Divert Service ; a network service that allows a customer to have a network redirect incoming calls to another number.
Call-drop-back - ensures efficient routing of calls to ported numbers. Is an additional loop which continues for duration of call, within donor network in a call path to a ported number. Called tromboning also.
Call Minder - a network based call answering service provided by BT. Incoming messages can be left if the customer's line is busy or not answering.
Call origination ; see originating operator.
Call return ; a user calling an engaged number can request that the call is returned when the number is free.
Call routing apparatus - any equipment capable of switching two-way live speech telephone calls between two or more exchange lines and two or more extensions, such as PBXs, Automatic Call Distribution equipment and key telephone systems.
Call termination ; see terminating operator.
Calls and Access - A wholesale product available from BT which allows service providers to rent a BT telephone line and then supply it and calls over it to the service provider’s own customers. The service provider sets the tariffs charged to the customer and is responsible for all customer service including reception of faults. BT continues to own and maintain the line.
Call transit ; see transit segment.
Call waiting ; caller to an engaged number is placed on hold whilst the called line is notified of a call waiting to be answered.
Caller display - a service based on calling line identity that allows customers to see the number from which someone is calling them before they answer the telephone.
Calling card - a service that allows calls made from a telephone to be billed to a different telephone or credit card account.
Calling Line Identity (CLI) – a facility that enables identification of the number from which a call is being made.
CAMEL (Customised Applications for Mobile Network Enhanced Logic) ; allows roamed customers to access the value added services of their home network, even if the visited network does not support those services.
Capacity based charging ; charging on the basis of the costs of the capacity in the network and switches needed to provide a service.
Carrier pre-selection (CPS) - the facility offered to customers which alows them to opt for certain defined classes of call to be carried by an operator selected in advance (and having a contract with the customer), without having to dial a routing prefix or follow any other different procedure to invoke such routing.
CATV - Community Antenna Television, Cable Television
CCA - Cable Communication Association - Trade body for cable companies.
CDMA - Code Division Multiple Access
CD Rom ; read-only memory stored on a compact disk.
Centrex - a service provided over the PSTN as an alternative to customers having their own Private Branch Exchange (PBX), with the PSTN providing the switching of calls between terminals on the customer's site as well as calls to and from other users of the PSTN.
Central London Zone (CLZ) pricing ; BT offers reduced charges for some leased lines if both ends are within the 0171 exchange area.
CEPT – Conférence Européenne des Postes et des Télécommunications (the European Conference of Posts and Telecommunications). The original body concerned with pan-European topics for Posts and Telecommunication services.
Chatline ; A service which allows more than two persons simultaneously to conduct a telephone conversation with one another and where the persons concerned are normally strangers to each other to begin with.
Circuit/path resilience - the ability of the network to re-route a circuit over a different physical path when the original path becomes unusable for whatever reason.
Class licence ; a licence granted by the Secretary of State to a class of people which permits any within the relevant class to provide specified services without the need for an individual licence or, in certain circumstances, the need to register the system or provide the service.
Classified business directories ; business directories which comprise directory information listings and advertisements paid for by those businesses which are ordered into classifications by type of business.
CLI - see Calling Line Identition
Co-axial - a type of cable generally used for conveying television pictures.
Co-location - The ability for other operators to install equipment in BT's local exchanges in order to supply services over the local loop.
Co-regulation: Regulator and stakeholders work together with, typically, regulator setting framework for stakeholders to work within. Enforcement powers exist but rarely used in practice.
Code of Practice on the Use of Directory Information ; the code of practice on the use of directory information, produced by the Data Protection Registrar. Copies are available on the Data Protection Registrar’s website.
Code powers - under the Telecommunications Code, operators may be conferred certain rights by the occupiers of land (subject to certain provisions in default) or, in the case of street works, by virtue of certain statutory provisions. These rights enable operators to install and maintain their telecommunications apparatus, such as cables and switches, in or under land, `for the statutory purposes', which are defined in paragraph 1(1) of the Code as 'the purposes of establishing and running the operator's system'.
Common Costs ; costs that are incurred in the supply of all or a group of products or services provided by the company and cannot be directly attributed to any one product or service.
Common Technical Requirements (CTRs) - a European standard specifying, for applicable terminal equipment, the mandatory conformity approval requirements for connection to public telecommunications networks.
Comparable Performance Indicators ; quality of service measures on a like for like basis.
Competition Act (CA); Competition Act 1998
Competitive service - BT’s interconnection services that were deemed to be competitive at the commencement of the Network Charge Controls and interconnection services that were introduced after the commencement of the Network Charge Controls. BT is free to set the charges for these services subject to normal competition rules.
Concentrator ; the part the local exchange which is positioned close to the customers. It is sometimes within the local exchange, and sometimes located remote from the local exchange.
conditional access ; the systems and technology used to ensure that only those consumers who have paid to receive a service, or who live in a given geographical area are able to watch that service ie access is restricted to those who meet the conditions. Generally conditional access systems used with pay television use scrambling but other methods may be used to prevent unauthorised access
Condition 13 ; Condition 13 of BT's licence relating to the supply and pricing of Standard Services for interconnection.
Consumer - residential and business customers
Consumer equipment - also known as customer premises equipment (CPE) or customer apparatus. Equipment on consumers' premises which is not part of the public telecommunications network and which is directly or indirectly attached to it.
Controlled Services ; Those premium rate services which are currently defined in licences as being subject to controls. They comprise of chatlines and live conversation services.
Controlled premium rate services ; Those premium rate services defined in the proposed licence modification as being subject to controls.
Cooperative Services ; a Cooperative Service is a service which requires a specific capability between networks in both the originating and terminating networks, both within the networks and at the point of interconnect, or which requires interconnection between networks in order to be commercially viable. Examples of Co-operative Services are normal telephony, premium rate services, Ring Back When Free, and CLI display services.
Copper line (or metallic line) - the main transmission medium used in telephony networks to connect a telephone or other apparatus to the local exchange. Copper lines have relatively narrow bandwidth and so have limited ability to carry broadband services such as video unless combined with an enabling technology such as ADSL.
Core database ; term to describe a database which includes aggregated directory information from different telecommunications companies.
Corporate subscriber - any subscriber who is party to a contract with a telecommunications service provider for the supply of publicly available telecommunications services, other than an individual.
Correspondent - a bilaterally negotiated arrangement between a provider of telecommunications services in eg the UK or the US and a provider of telecommunications services in the other of the UK or the US for provision of an international telecommunications or enhanced telecommunications service, by which each party undertakes to terminate its country traffic originated by the other party. (USA definition)
Correspondent agreements ; An agreement with a far end operator, for that operator to receive and terminate international calls originating on the near end operator's facilities.
Cost Attribution - allocation and apportionment of costs to relevant businesses and activities.
Cost Benefit (Analysis) ; the analysis and comparative assessment of the relative costs and benefits of a particular course of action.
Cost of capital ; a firm’s cost of capital can be defined as the rate of return that could be earned in the capital market on securities of equivalent risk. In general, the higher the riskiness of the firm's activities, the higher its cost of capital, since investors typically require compensation for greater risk. For a firm financed by debt and equity, the cost of capital will be a weighted average of its cost of capital from both source.
Cost-oriented pricing - where all elements of the price charged can be related to costs.
Cost-Plus – a charge which covers the costs incurred by the network operator in providing services for other operators, including a reasonable return on capital employed.
COST 219 - the UK Group which implements the work of the European organisation for Co-operation in the fields of Science and Technology in the area of future telecommunications and teleinformatics for disabled people. The group acts as an independent forum for promoting the needs of people with disabilities and elderly people with regard to telecommunications.
Country code - the combination of 1, 2 or 3 digits characterizing the called country.
CPE ; see Customer premises equipment
CPS - see Carrier pre-selection
Cross subsidy - the financing of losses made in one market by pricing below incremental costs from profits made in another.
Crosstalk - the phenomenon whereby telecommunications signals on one circuit can leak across to another, potentially degrading the performance on the affected circuit.
CSI ; Customer-Sited Interconnect.
CT2 - The Cordless Telephony Standard. A digital system using frequency shift keying in the 864 to 868 MHZ band using time division duplex.
CTRs - see Common Technical Requirements
CUG - Closed User Group
Current Cost Accounting (CCA) ; an accounting convention, where assets are valued and depreciated according to their current replacement cost whilst maintaining the operating or financial capital of the business entity.
Customer apparatus - See Consumer equipment
Customernetwork interface – where a public telecommunications network is connected to a customers network or apparatus (at the Network Terminating Point) the network and the customers system must each be able to understand the technical operation of the other in order for services to interoperate across the connection boundary. The customers system and the network must both provide an interface at the point of connection and only where these interfaces are matched will there be interoperability. The technical characteristics that allow for that understanding is the customernetwork interface.
Customer Premises Equipment (CPE) ; sometimes referred to as customer apparatus or consumer equipment, being equipment on consumers’ premises which is not part of the public telecommunications network and which is directly or indirectly attached to it.
DAM - see Detailed Attribution Methods
DAS ; see Directory Assistance System
Database Information maintained in a computer storage system.
Data Network Identification Codes - codes allocated from the Numbering Scheme which allow for the routing of data services over telecommunications networks
Data Protection Commissioner - an independent officer who is appointed by Her Majesty the Queen and reports directly to Parliament. Originally known as the Data Protection Register.
Data Protection Principles ; the eight Principles in the Data Protection Act 1984 which set out rules which data users must comply with in the use of personal data. The Principles protect the rights of individuals rather than the users of their personal data.
Data Protection Register (DPR); a register held by the Data Protection Registrar of data users who hold personal data and computer bureaux who provide services in respect of personal data which is open to public inspection. Every data user who holds personal data must, unless all the data are exempt, apply for registration. 1995.
Data Protection Registrar ; an independent officer who is appointed by Her Majesty the Queen and reports directly to Parliament. Will be known as the Data Protection Commissioner when the Data Protection Act 1998 comes into force.
Data user ; definition used in Data Protection Act 1984 to mean a person or organisation which controls the content and use of a collection of personal data.
DAVIC - see Digital Audio Visual Council
DBS - Direct Broadcast to the home by Satellite.
DCMS - Department of Culture, Media and Sport
DCS - 1800 Digital Cellular System at 1800 MHz
DDA ; The Disability Discrimination Act (1995) (see paragraph 3.16).
Direct Dialling In (DDI) ; a switchboard’s capability to route an incoming call to the extension dialled without the intervention of an operator
DDSN ; see Digital Derived Services Network
De-averaging ; the move from a single averaged tariff or charge to separate ones based on differing geographical areas or types of service.
DECT ; see Digital European Cordless Telecommunications
DECT Handsets (Digital European Cordless Telecommunications) ; cordless handsets for domestic and business use.
Detailed Attribution Methods (DAM) – a handbook produced by BT which provides greater detail of the methods employed in attributing turnover, costs, assets and liabilities between BT's Businesses (as defined for regulatory purposes). It supports the Financial Statements (Regulatory Accounts) and the Accounting Documents.
Detailed Valuation Methodology (DVM) ; This sets out the methodology by which current cost valuations are obtained.
Deep discounting ; the retailing of the second and subsequent premium TV channels at significantly lower prices than the first premium channel
Designated Maintainer - a maintainer approved under [section 20 of] the Telecommunications Act 1984 with whom a user has entered into a contract for the maintenance of Call Routing Apparatus comprised in a system run under the SPL or TSL - Obsolete from 9 September 1996.
DfEE - the Department for Education and Employment.
DGIV ; Directorate General IV of the European Commission which is responsible for enforcing the competition provisions of the Treaty of Rome.
Dial-up connectivity ; connections made to a data network using the switched network to provide a voiceband or data bearer.
DIEL ; the Advisory Committee on Telecommunications for Disabled and Elderly People.
Digital ; the coded representation of a waveform by, for example, binary digits in the form of pulses of light, as opposed to analogue which is the direct representation of a waveform.
Digital Audio Visual Council (DAVIC) - a world consensus forum set up to generate global digital telecommunications standards in the area of broadband switched mass-marked networks and services.
Digital Derived Services Network (DDSN) ; the overlay network used by BT to provide interalia some of its Number Translation services.
Digital European Cordless Telecommunications (DECT) - a system for office cordless networks and suitable for more general cordless use including Telepoint type networks.
Digital International Switching Centre - Last inland exchange for outgoing international calls and first inland exchange for incoming international calls. Calls are switched at the DISC for onward conveyance internationally or nationally.
Digital Junction Switching Unit (DJSU) - similar to DMSU (see below) but used mainly for connecting calls around major conurbations.
Digital Local Exchange (DLE) ; the telephone exchange to which customers are directly connected.
Digital Main Switching Unit (DMSU) ; a trunk exchange primarily used for connecting long distance calls.
Digital Subscriber Line (DSL) - A technology that allows the use of a copper line to send higher bandwidth services (eg a television picture) to a customer’s premises.
Digital Subscriber Loop Multiplex (DSLAM) ; it is located in the co-location space of an Operator at an exchange site. It is composed of a multiplex and the DSL modems necessary to operate DSL services over the loops served by the Operator from the exchange.
Digital technology ; this enables information of all types to be transmitted in digital form over networks ; it is faster than analogue systems.
Digital Video Broadcasting (DVB) Project - a European consensus group, with experts from 140 organisations representing broadcasters, administrations, manufacturers and network providers, which proposes solutions to technical and commercial issues affecting video broadcasting using digital techniques.
Digitalization - the process of converting information in analogue form into digital form.
Direct Access - the situation where a customer is directly connected to a telecommunications operator by a wire, fibre-optic or radio link to connect that customer to the public telecommunication network.
Director General - the Director General of Telecommunications
Directory Assistance System (DAS) - BT=s product database which is used to provide operator assisted directory services. It comprises a database and search software.
Directory enquiry service (DQ) ; directory information service which is operator assisted and involves the operator looking up entries on a database.
Directory information ; categories of information including name, telecommunications number, address (it does not have to be a full address) customer type (business or residential), directory status and type of number (fixed, mobile, fax etc) which are collected from customers to provide telecommunications directories and/or directory information services.
Directory Information Forum - the industry group made up of users of directory information
Directory information product ; Printed directories or directories in machine readable media, eg CD-ROMs, which are designed to facilitate use of the telecommunications system.
Directory information service ; service providing directory information by means of a telecommunications system which facilitates the use of that telecommunications system and may refer to both a directory enquiry service and an on line directory information service
Directory status ; a classification agreed with the customer denoting which services and products their information may and may not be used for.
DISC - Digital International Switching Centre
Distribution networks -the network over which signals and messages are transmitted eg a telephony or cable TV network, or a terrestrial or satellite TV broadcast network.
DJSU - see Digital Junction Switching Unit
DLE - see Digital Local Exchange
DMA ; Direct Marketing Association.
Digital Main Switching Unit (DMSU) ; a trunk exchange primarily used for connecting long distance calls.
DQR ; a directory status classification whereby the customer's directory information is available from directory enquiry services but is not included in the phone book.
Domestic Premium Rate Service - an information, entertainment or other value-added service consisting of or including speech, music or other sounds or signals and in relation to which such service is: (a) provided by a Service Provider from a set of premises located in the United Kingdom (whether or not the Service Provider is a PTO); (b) conveyed by means of a Public Switched Telephone Network; (c) accessed by a customer of a PTO by means of a Public Switched Telephone Network; (d) readily distinguishable as such a service by means of its dialling code;
Dominant ; a dominant firm is one which is able to act largely independently of its competitors and customers in terms of pricing or output decisions. Dominance has to be assessed within the context of an analysis of the degree of competition within a relevant market.
Donor Operator ; An operator whose customer number(s) are in the process of being, or have been passed or ported to a Recipient Operator.
Double Tandem Conveyance - a BT service provided to interconnected network operators whereby a call passed on to BT's network at a tandem exchange (ie one that routes calls between exchanges but not having direct connections to end users) is passed to another tandem exchange and then on to a local exchange (ie one that does not have direct connection to end users) and finally on to the end user.
DPA ; Data Protection Act 1984.
DPD ; Data Protection Directive 1995.
DPR ; see Data Protection Register
Digital Subscriber Loop (DSL) - A family of technologies generically referred to as DSL, or xDSL, capable of transforming ordinary phone lines (also known as "twisted copper pairs") into high-speed digital lines, capable of supporting advanced services such as fast Internet access and video-on-demand. ADSL (Asymmetric Digital Subscriber Line), HDSL (High data rate Digital Subscriber Line) and VDSL (Very high data rate Digital Subscriber Line) are all variants of xDSL.
DSL technology ; digital subscriber line technology.
DSLAM-(Digital Subscriber Loop Multiplex)- it is located in the co-location space of an Operator at an exchange site. It is composed of a multiplex and the DSL modems necessary to operate DSL services over the loops served by the Operator from the exchange.
DSMU (Digital Main Switching Unit) ; a trunk exchange primarily used for connecting calls between DLEs.
DTI ; The Department of Trade and Industry.
Ducts ; the tubes through which cables are laid.
DXC - digital cross connect (for connection to international network)
Easy Access - a facility allowing a BT customer to select an alternative operator using a short access code, usually 3 or 4 digits in length. Outgoing calls use BT's lines and network to the first point of interconnection and are then switched to the chosen operator
EC - Electronic Commerce
ECTRA ; European Committee for Telecommunications Regulatory Affairs. ECTRA is the major European forum for the discussion of regulatory issues, set up within the framework of the European Conference of Posts and Telecommunications (CEPT).
ECTRA-PTN ; the ECTRA Project Team on Numbering. A team, set up by ECTRA, to take forward European matters relating to Numbering. It reports to the main ECTRA meetings. ECTRA has a number of such Project Teams covering different aspects of telecommunications.
EC Licensing Directive - Directive 97/13/EC of the European Parliament and of the Council on a common framework for general authorisations and individual licences in the field of telecommunications services (OJ [1997] L117/15) (19 April 1997).
E-Commerce - The action of buying online or establishing an online store-front. Also, using technology to speed up and make more efficient the transaction of commerce at all stages of the process from production to delivery.
Economies of scale ; reductions in unit cost savings which occur when a product is produced in greater quantities
Economies of Scope ; cost savings which occur when two or more products are produced together, ie the provision of service B reduces the unit cost of supplying service A.
Efficient component pricing rule (ECPR) ; A rule for determining interconnection prices, under which the price is composed of the incremental cost of providing the interconnection service plus the profit (including contribution to common costs) that the network operator foregoes by selling interconnection to another operator rather than a service to the final customer.
ECTRA ; see European Committee of Telecommunications Regulatory Affairs.
EIR - Equipment Identity Register
Electronic Data Interchange - EDI ; network which allows access from different locations for transmitting orders, invoices and payments electronically. The technology used is similar to e-mail but has a higher level of security. EDI operators have computers which carry out the necessary centralised processing
Electronic Programme Guide (EPG) ; software in the receiver which takes data on programmes and displays these in the form of an on-screen guide. The guide displays information about what is on now and next on each channel as well as future programmes. Viewers may also be able to use the on-screen menus to order pay per-vie services or to access interactive services.
Enabled DLE ; A DLE with ‘grooming capability’, in other words capability to take traffic off the PSTN onto the IP network.
Enhanced Services ; services that can be economically provided by independent service providers (ie those who do not build their own telecommunication network infrastructure) in competition with network providers as long as they can gain access to Network Services. The regulation of BT ensures that this is the case in respect of access to BTs Network Services. Examples of Enhanced Service are the provision of content for premium rate services and the provision of retail Internet services.
Enhanced Telecommunications Service - any telecommunications service that involves as an integral part of the service the provision of features or capabilities that are additional to the conveyance (including switching) of the information transmitted. (USA definition)
Enhanced television services television services which include interactive applications as well as audio and video.
End-use Charging - Under a system of end-use charging, BT’s network charges would be allowed to vary according to the use to which the network components are put.
End-user component: a device for receiving digital services in respect of which the use of Access Control services is necessary. Set-top boxes for the receipt of digital interactive services delivered via television sets is one example.
EPG - Electronic Programme Guide
EPN - Electronic Platform Highway
Equal access -the ability of a customer connected to one operator to choose to have their long-distance and international calls carried by that operator or by another operator, with no extra processes or procedures required if they choose that other operator rather than the operator to whom they are connected. (Often known as Carrier Pre-selection)
Erlang ; The unit of traffic volume corresponding to the number of simultaneous calls in progress at any given time or averaged over a period of time.
Erlang Efficiency ; The rate of Erlangs per circuit on a given route.
Essential requirements ; the non-economic reasons in the public interest, which may cause a Member State to impose conditions on the establishment and/or operation of telecommunications networks or the provision of telecommunications services. In the EC ONP framework, those reasons shall be the security of network operations, the maintenance of network integrity and, where justified, the interoperability of services, data protection, the protection of the environment and town and country planning objectives as well as the effective use of the frequency spectrum and the avoidance of harmful interference between radio-based telecommunications systems and other space-based or terrestrial technical systems. Data protection may include protection of personal data, the confidentiality of information transmitted or stored and the protection of privacy.
ETO ; the European Telecommunications Office. A staffed office, located in Copenhagen, funded by ECTRA. It carries out and co-ordinates studies into European telecommunications matters on behalf of the EC and others and works in conjunction with ECTRA and its Project Teams.
ETSI - European Telecommunications Standards Institute has the primary responsibility within Europe for the production of telecommunications standards for pan-European application.
European Committee for Telecommunications Regulatory Affairs (ECTRA) - ECTRA is the major European forum for the discussion of regulatory issues, set up within the framework of the European Conference of Postal and Telecommunications Administration (CEPT).
EU ; European Union
Ex-directory ; a directory status classification whereby the customer's directory information is not available from any directory information services or products.
Extranet - a network connecting a group of entities using Internet protocols, but being separate from the Internet. Often parts of an organisation=s internet shared with other organisations
Fair Trading Condition (FTC) ; is modelled on Articles 85 and 86 of the EC Treaty and prohibits the abuse of a dominant market position and agreements which restrict or distort competition.
Far-end breakout ; a feature of private networks that routes a call made to a public network number to breakout on to a public network as close to that number’s line as possible
Farland network ; a pan-European telecommunications network linking cables and network facilities owned by BT’s joint venture companies in Europe
Fax Preference Service (FPS) ; a service established by the Direct Marketing Association to help reduce the chances of customers receiving unsolicited advertising communications via fax. It operates along similar lines to the Telephone Preference Service.
Featurenet - BT's virtual private network service.
Federal Communications Commission (FCC) - the US regulatory body set up in 1934 to regulate all inter-state and foreign communications by wire, radio, television and radio. Intra-state communications are regulated by state public utilities commissions.
Federation of Communication Services (FCS) - the industry body for the mobile telecommunications industry.
Fibre optics - See optical fibre.
File Transfer Protocol (FTP) ; provides a basic service for the reliable transfer of files from one machine to another.
Financial Statements ; documents that collectively make up, inter alia, the regulatory accounts reflecting accounting separation and interconnection standard services. The statements are audited to check that they fairly represent the financial results for the Businesses which are divided for regulatory purposes (inter alia to help disclose unfair cross subsidies between and within businesses and that interconnection charges can be shown to be fairly derived from costs and applied without discrimination).
First generation number translation service ; a number translation service provided from the DDSN.
Fixed costs ; those costs which are fixed irrespective of the quantity produced (or sold). For example the cost of producing a television programme or channel is fixed irrespective of the number of people who watch the programme or subscribe to the channel. See also marginal cost and average cost.
Fixed link telephony operators -operators providing fixed as opposed to mobile telephony services.
Fixed/mobile integration - (also known as fixed mobile convergence) the merging of fixed and mobile services into an integrated service whereby the customer will be offered both fixed and mobile services and will receive one bill and/or receive and make calls using one terminal.
Fixed publicly available telephone services ; means the provision to end-users at fixed locations of a service for the originating and receiving of national and international calls, including voice telephony services and may include, in addition, access to emergency ‘112’ services, the provision of operator assistance, directory services, provision of public pay telephones, provision of service under special terms or provision of special facilities for customers with disabilities or with special social needs but does not include value added services provided over the public telephone system.
Fixed radio access ; fixed link telecoms service that connects the network to the consumer's premises by radio instead of copper line or fibre
FMI (Fixed Mobile Integration, but also known as Fixed Mobile Convergence) ; the merging of fixed and mobile services into an integrated service whereby the customer will be offered both fixed and mobile services and will receive one bill and/ or receive and make calls using one terminal.
Former duopolists ; Until December 1996, when the UK liberalised international facilities, BT and Mercury were the only operators at the UK end licensed to own and operate international facilities.
FPS - see Fax Preference Service
Frame relay service - a packet switched data service (see packet service) providing for the interconnection of Local Area Networks (LANS) and access to host computers at higher speeds (up to 2 Mbit/s) than those provided by an X.25 service.
Freephone ; automated reversed charge mechanism whereby caller pays nothing while company receiving call pays all call charges and associated costs (line rental, enhanced services)
Freephone number ; a number which can be reached free of charge to the caller often beginning 0800 or 0500.
Freephone helplines ; helplines run on a not for profit basis providing access to advice, information, listening support, befriending, counselling and/or referral in the fields of health and social welfare where calls are free of charge to the caller.
Freephone Services - telephone services offered by network operators and service providers for which there is generally no charge to the caller.
Free-to-air television service ; a television service which can be received in a given area without charge to the viewer. Some free-to-air services may be broadcast in scrambled form in order to limit access to viewers in a specific geographic area. Other free-to-air services may be broadcast in the clear ; ie unscrambled .
FRIACO - the provision of a Flat Rate Internet Access Call Origination via a wholesale unmetred Internet access product from BT at their local exchanges.
FTC - see Fair Trading Condition
FTP - see File Transfer Protocal
Functional Specification ; A document published from time to time by the Director General, following consultation with all Licensees, which specifies technical and other principles which are intended to enable the efficient implementation and utilisation of portability.
FUG ; Freephone User Group. Recently established group set up to represent the interests of businesses that rely on freephone numbers as marketing tools.
Full-line forcing ; a form of bundling where, in order to obtain an individual product or service, the full range of products or services must be purchased even though there might be demand for only one product or service within the bundle .
Gateway - a facility which adapts signals and messages of one network to the protocols and conventions of other networks or services.
GATS/WTO agreement - (General Agreement on Trade in Services/World Trade Organisation). On 16 February 1997, the participating countries concluded an agreement on free trade in telecommunications.
General authorisation ; an authorisation, regardless of whether it is regulated by a ‘class licence’ or under general law and whether such regulation requires registration, which does not require the undertaking concerned to obtain an explicit decision by the national regulatory authority before exercising the rights stemming from the authorisation
Geographic number ; a number from the national numbering plan where part of its digit structure contains geographic significance used for routing calls to the physical location of the network termination point of the subscriber to whom the number has been assigned.
Geographic portability - the ability of customers to transfer their numbers between operators on fixed telecommunications networks when they switch their operator
Geographically averaged prices ; prices established by averaging the costs of network elements across the country so that customers in different areas of the country do not pay different rates.
GIP - Global Inventory Project
GMSC (Gateway Mobile Services Switching Centre) ; the first point of contact between the PSTN and the GSM network.
GPRS ; General Packet Radio Service
Group (Company) ; A parent undertaking and its subsidiary undertakings as defined in Section 262(1) of the Companies Act 1985.
GSM - Global Standard for Mobile Telephony
GSM 900/ 1800 MHz ; Global System for Mobile Communications in the 900 and 1800 MHz frequency bands.
Hand-over Distribution Frame (HDF) ; a copper distribution frame.
Harmonised European Short Codes (HESC) ; These are short numbers intended to have a common significance in all European countries. Examples are ‘00’ for international access, ‘112’ for emergency services, ‘118’ for access to competitive Directory Enquiry services
Harmonised standard ; a technical specification adopted by a recognised standards body under a mandate from the Commission in conformity with the procedures laid down in Directive 98/34/EEC for the purpose of establishing a European requirement, compliance with which is not compulsory.
HCA - Historic Cost Accounting ; a universally recognised accounting convention. Costs, turnover, assets and liabilities are generally recorded at the value when the transaction was incurred and where assets are valued and depreciated according to their cost at the time of purchase.
Head-end - the control centre for a cable system where signals such as terrestrial and satellite TV channels are received, processed and sent for distribution down the cable system.
HLR ; Home Location Register
HMG - Her Majesty=s Government.
HMT ; Her Majesty’s Treasury.
HTML - Hyper Text Markup Language
Host/remote concentrator ; a concentrator can be remote from the host DLE or co located with it.
HSCSD - High Speed Circuit Switched Data
Hubbing ; The routing of international traffic via an intermediate third country.
IBC - Integrated Broadband Communications
IBL ; Intra-Building Links.
ICD - see Interconnection Directive
ICSTIS ; Independent Committee for the Supervision of Standards of Telephone Information Services.
ICT ; information and communications technology.
IDD -international direct dialling.
IDIS - see International Directory Inquiry Service
IEC ; Interconnection Extension Circuit.
IFL - see International Facilities Licence
IMSI - International Mobile Station Identity
IMTS - International Message Telephone Service
IN ; Intelligent Network. A telecommunications network in which the network intelligence is centralised and separated from the switching function.
INCA ; BT’s automated billing system for interconnection charges
In Contact ; the name which BT uses to market its Residential Limited Service Scheme.
In-the-clear television service ; television services that are broadcast without scrambling and are thus, accessible by all viewers within the reception area who have the necessary equipment. In-the-clear services are a sub-set of free-to-air services.
Incremental costs ; the capital and operating costs that arise as a result of the provision of the "increment". In contrast to fully allocated costs, the incremental costs include only those costs that are caused by the provision of the increment. So long as revenue exceeds incremental costs, the company increases its value by providing the increment.
Incremental revenue - the additional revenues derived from selling a service as part of a bundle.
Indefeasible Right of Use (IRU) ; effectively, ownership of capacity on an international cable by someone other than an original member of the cable consortium.
‘Independent’ private payphone ; a payphone run by a private individual or organisation and located on private premises. Public access to these is determined by the private renter/owner of the payphone who also sets the tariff and collects the revenues.
Index ; A numerical scale used to show how a variable has changed over time against a given reference number, normally 100.
Independent Service Provider (ISP) - entities which provide telecommunications services over fixed or mobile networks, or services with a telecommunication service component, to the public at large but do not own or operate telecommunications networks. Some independent service providers may not use telecommunication networks eg they may be publishers of printed directories
Indirect access – where a customer’s call is routed and billed through operator A’s network even though the call originated from the network of operator B. It is the generic term for both easy access and equal access
Individual licence ; an authorisation which is granted by a national regulatory authority and which gives an undertaking specific rights or which subjects that undertaking’s operations to specific obligations supplementing the general authorisation where applicable, where the undertaking is not entitled to exercise the rights concerned until it has received the decision by the national regulatory authority.
Individual Subscriber - a living individual who is party to a contact with a telecommunications service provider for the supply of publicly available telecommunications.
Inductive Coupling ; sometimes known as magnetic coupling, it is the principle by which a coil within a hearing aid picks up audio frequencies by means of the magnetic field generated by telephone handsets, loudspeakers or other similar equipment (eg inductive loops).
Industry Interconnection Advisory Group ; a forward looking industry forum for discussion of interconnect and interoperability issues on which cooperation is required.
Information Society service ; any service normally provided for remuneration, at a distance, by electronic means and at the individual request of a recipient of services.
Integrated Services Digital Network (ISDN) - a network based on the existing digital PSTN which provides digital links to customers and end to end digital connectivity between them. ISDN2 provides a maximum bandwidth of 128kbit/s.
Intelligent Network ; a telecommunications network in which the network intelligence is centralised and separated from switching functions. These allow more flexibility than switched based systems, customers can be given access to their own database entries to carry out changes
Inter-tandem conveyance - Interconnection service that involves the use of a tandem switch and transmission between two tandem switches. It is sub-divided into three distance bands.
Inter-tandem transit - Interconnection service that involves the use of two tandem switches and one inter-tandem transmission link. It is sub-divided into three distance bands.
Interactive services ; this term covers two forms of interactivity. The first is where viewers use the remote control to click to applications, which are included in the broadcast stream. The second form of interactivity is where the modem is used to communicate with a remote server.
Interconnection ; the physical and logical linking of telecommunications networks used by the same or a different organisation in order to allow the users of one organisation to communicate with users of the same or another organisation, or to access services provided by another organisation. Services may be provided by the parties involved or other parties who have access to the network.
Interconnection Directive - An EU Directive which came into effect from January 1995, setting rules for, amongst other things, who has rights and obligations to interconnect and the terms on which it should take place.
Interconnect Policy Forum (IPF) ; a forum consisting of industry representatives and chaired by OFTEL which meets periodically to discuss commercial and regulatory aspects of interconnection which are of interest to the industry generally.
Interconnect specific service - Services that other licensed operators need to buy for the purposes of interconnection with BT.
Interconnect User Part (IUP) - (comprising signalling messages to establish and control calls) of the UK version of ITU/CCITT Signalling System No 7.
Interconnection Directive (ICD) - an EU Directive which came into effect from January 1995, setting rules for, amongst other things, who has rights and obligations to interconnect and the terms on which it should take place.
Interconnection services -services provided by one telecommunications organisation to another for the purpose of the conveyance of messages and information between the two systems and including any ancillary services necessary for the provision and maintenance of such services.
Interface - a set of technical characteristics describing the point of connection between two telecommunication entities; for example, between two telecommunication networks, or between a telecommunication network and customer apparatus.
Internal Rate of Return (IRR) - The discount rate which equates the prospective revenue streams of a project with the costs of the project, also known as Economic Rate of Return.
International direct dial conveyance - Interconnection service that involves use of one BT digital international switching centre (DISC) and onwards conveyance enabling calls to be made to other countries.
International Directory Inquiry Service (IDIS) ; a group of overseas operators who cooperate to provide international directory enquiry services to their customers by allowing member operators to access their directory databases on-line. At the European level this takes place through the European International Directory Enquiry Group (EIDQ).
International facilities ; Infrastructure owned and operated by a licensed operator for conveying traffic between countries. In the United Kingdom the international facilities licensees are licensed to own and operate international facilities at the UK end on all international routes.
International Facilities Licences (IFL) - a licence granted under the Telecommunications Act 1984 authorising the connection of a UK telecommunication system to a telecommunication system outside the UK adn the provision of telecommunication services over the system to countries outside the UK.
International number - the number to be dialled following the international prefix to obtain a called party in another country.
International prefix - the combination of digits to be dialled, following access to the PSTN, by a caller making a call to a recipient in another country to obtain access to the automatic outgoing international equipment. For the UK, this prefix is "00".
International Private Leased Circuit (IPLC)- circuits leased from international facilities operators, which cross one or more international boundaries.
International Simple Voice Resale - (ISVR) - an international service provided by an operator to customers using the international facilities owned by other operators. In the case of an outgoing call, the operator collects traffic from the public telecommunications network, transfers it to a line leased from a facilities operator, and then hands it over to a Public Telecommunications Operator in an overseas country who will deliver the call to its destination. It therefore involves breakout onto the public telecommunications network at both ends, but with the international leg of the call being carried on leased circuits. ISVR traffic bypasses the accounting rate system
Internet - a global network of networks, mainly narrowband, accessed by users with a computer and a modem via a service provider.
Internet service provider ; a service provider who provides access to Internet services.
Interoperability - interoperability means the technical features of a group of interconnected systems (>systems includes equipment owned and operated by the customer which is attached to the public telecommunication network) which ensure end-to-end provision of a given service in a consistent and predictable way.
Intertandem transmission ; transmission between DMSUs.
Intranet ; closed data network linking a number of sites using standard internet protocols
IP - Internet Protocol - packet data protocol used for routing and carriage of messages across the internet.
IPF - see Interconnect Policy Forum
IPLC - International Private Leased Circuit ; an international leased line.
IPR - Intellectual Property Rights
IRR ; see Internal Rate of Return
IRU - see Indefeasible Right of Use
IS - Information Society
ISI ; In-Span Interconnect.
ISDN - see Integrated Services Digital Network
ISP - see Independent Service Provider
ISUP Migration - migration of the UK interconnect signalling system from C7 (Interconnect User Part) to ETSI ISUP (ISDN User Part).
ISVR - International Simple Voice Resale
ISVR licence ; UK licence authorising an operator to receive incoming and offer outgoing calls conveyed via ISVR.
IT - Information Technology
ITC ; The Independent Television Commission.
ITC - International Transmission Centre
IUP - see Interconnect User Part
JV - Joint Venture
Kingston ; Kingston Communications (Hull) PLC ; telephone company which operates in the Hull area.
LEO - Low Earth Orbit
Local area networks (LANS) ; a network allowing the interconnection and intercommunication of a group of computers, primarily for the sharing of resources and exchange of information (eg e-mail)
Local Delivery Operator (LDO) - a cable system operator with an LDO licence, as opposed to a broadband cable licence. This type of licence has been granted since 1994. An LDO=s Broadcasting Act Licence is awarded under the 1990 Broadcasting Act rather than the 1984 Cable and Broadcasting Act and this has had knock-on effects on the Telecommunications Act Licence. The only two significant differences between Broadband Cable Licences and LDO Licences are that LDOs can deliver entertainment services to the end user by radio, and that any construction obligations for LDOs are in the Broadcasting Act Licence so are monitored by the ITC whereas in the Broadband Cable Licences these obligations are monitored by OFTEL.
LEA ; local education authority
Lead-in duct - is defined as the primary route or routes leading from BT's off-site network onto the site.
Leased lines (also known as private circuits) a fixed unswitched communication link between two points.
Leased Lines Directive ; Directive 92/44/EEC of 5 June 1992 on the application of open network provision to leased lines (OJ [1992] L165/27, as amended)
Licensing Directive ; Directive 97/13/EC of 10 April 1997 on a common framework for general authorisations and individual licences in the field of telecommunications services, (OJ [1997] L117/15)
Light User Scheme (LUS) – BT’s special scheme launched in 1993. It was created to ensure that customers on low incomes and other disadvantaged customers could be connected to the network at an affordable price. Normal rental charge applies, but users receive a rebate if call charges are less than £12 per quarter.
Live conversation services ; A definition of the group of premium rate services which includes the provision of live telephone conversation either between the provider of the service and the caller or two callers to the provided service.
Local access ; connection between the customer's premises and the local PSTN exchange
Local Call Fee Access ; Calls to non-geographic NTS services for which calling customers are charged at the local call rate
Local loop - the access network connection between the customers premises and the local PSTN exchange, usually a loop comprised by two copper wires.
Local loop unbundling (LLU) ; If local loop unbundling is mandated other operators will be able to ‘own’ BT’s access network connection between the customers’ premises and the local exchange (generally, the digital local exchange), which is usually a loop comprising of two copper wires. The customer would then be able to choose another supplier to provide service, and would cease to have a contract with BT.
Local rate - the rate for calls wihin the local area, the area being defined by the telecommunications operator serving the customer.
Long Run Incremental Costs (LRIC) Costs that arise in the long run as a result of providing a given 'increment', eg, an additional amount of numbers. Long run costs assume that the supply of numbers is variable (not fixed).
Low user scheme - the scheme whereby a customer with a low call bills gets a discount on line rental.
Machine readable media ; a medium that can be read by a machine eg CD-ROMs, computer tapes.
Main Company - the company with effective management control
Main distribution frame (MDF) - the apparatus in the local concentrator (exchange) building where the copper cables terminate and cross connection to other apparatus can be made by flexible jumpers.
MAN - Metropolitan Area Network
Managed Callstream - the BT facility (now called Managed Answering Service) providing call answering facilities within its network where service providers can rent a number of managed lines that can be used to convey their recorded messages.
Managed fall back routing - a facility where a network operator manages the re-routing of a customer's traffic on that customer's private circuits to overcome a fault or congestion.
Managed payphone ; a payphone installed on a private or commercial site, but operated under a contract with a payphone operator who pays the landowner a fee and collects the revenues and carries out maintenance.
Managed (private) network - the provision of all the necessary services to ensure that the owner or user of a private network is freed from all aspects associated with its operation and use, other than as a user of the services provided by the network.
Marginal cost ; the cost of producing an additional unit. Where there are economies of scale, the marginal cost will be lower than the average cost. In circumstances where all the costs of production are fixed (eg a television programme) the marginal cost for each additional viewer will be zero
Marginal price ; the difference between the price of the bundle including a given service and the price of the bundle (which may consist of only one service) without the service concerned. When products are sold as a bundle the marginal price will not be equal to the incremental revenue attributable to the service in question
Market Influence - The ability to raise prices above the competitive level in that market for a non-transitory period without losing sales to such a degree as to make this unprofitable.
Market power ; the ability to raise prices above the competitive level for a non-transitory period. See also dominant.
MBit/s - Mega (million) bits per second. A measure of the speed of transfer of digital information.
MCC ; Mobile Country Code*Main distribution frame (MDF) - the apparatus in the local concentrator (exchange) building where the copper cables terminate and cross connection to other apparatus can be made by flexible jumpers.
MDF - Main distribution frame the apparatus in the local concentrator (exchange) building where the copper cables terminate and cross connection to other apparatus can be made by flexible jumpers.
MEO - Medium Earth Orbit
MEPs - Members of the European Parliament.
Messaging service - a service enabling customers to exchange messages with each other through 'mailboxes' embedded in network equipment. Both voice and text messaging services are available, the latter often being called electronic mail or e-mail.
Metallic Line - see Copper Line
Migration - the movement of telephone numbers from one range (often a non-specified range) to another (specified) range.
Migration rate ; Measures the rate at which users on one tariff will move onto a new optimal tariff (assuming they keep the same usage pattern).
Minimum carriage obligation ; a contractual obligation to carry channels to a minimum percentage of a cable operator’s subscriber base. Normally these are set at between 80 and 100 per cent of subscribers. such obligations are a form of risk-sharing between broadcaster and cable operator reflecting the need on the part of the channel provider to recover its fixed costs.
MIU - Minimum Investment Unit (smallest unit of cable capacity that can be sold - currently 2Mb link)
MMC ; Monopolies and Mergers Commission.
MNC ; Mobile Network Code*
MNO ; Mobile Network Operator, ie Vodafone, BTCellnet, Orange or One2One.
Mobile data - covers a wide range of niche applications including vehicle location systems, data information services.
Mobility management - a service whereby a customer's calls can be forwarded to different locations depending on the customer's movements, together with an operator or message-leaving service if calls cannot be connected to the customer.
Mobile portability ; where a customer taking a service from a mobile operator (eg Vodafone, Orange) or Service Provider (eg People’s Phone) can retain their telephone number when they change to a different mobile operator or service provider.
Modem ; a device which converts digital signals from a data-transmitting terminal into modulated analogue signals which can be carried by a public telephone network.
Monthly contract package ; After paying a one-off fee for the phone and connection, the user pays a monthly rental charge which may include some inclusive call minutes.
MSC ; Mobile Services Switching Centre*
‘Multi-vendor’ circuits ; A leased line provided to a customer which uses the network infrastructure of more than one operator. eg ;one local end and a main link from operator A and a final mile circuit rented by operator A from operator B.
MVNO - Mobile Virtual Network Operator
Narrowband ; a service or connection allowing only a limited amount of information to be conveyed, such as for telephony. This compares with broadband which allows a considerable amount of information to be conveyed.
National Call Fee Access ; Calls to non-geographic NTS services for which calling customers are charged at the national call rate
National destination code (NDC) - a code field within the ITU-T Recommendation E.164 numbering plan which combined with the caller's or called party's number (in ITU-T terms the subscriber's number (SN)) will constitute the national (significant) number of the international ISDN number. The NDC will have a network and/or trunk code selection function.
National Numbering Scheme ; a scheme for the allocation and re-allocation of numbers which is specified by the Director General and made available by him for public inspection.
National rate - the rate for calls within the national call area, the area being defined by the telecommunications operator serving the customer
National Regulatory Authority (NRA) - the body or bodies, legally distinct and functionally independent of the telecommunications organisations, charged by a Member State with the elaboration of, and supervision of compliance with, telecoms authorisations.
National (significant) number - the number to be dialled following the national trunk prefix to obtain a customer in the same country but outside the same local network or numbering area.
National Technical Regulation (NTR) -. a national standard put in place, when no other (eg European) such standard exists for approval to customer premises equipment for connection to public networks.
NCC - (Network Charge Control) - regulation of BT's interconnection regime
Near video-on-demand - the transmission of a film or TV programme over several channels at the same time but with a short delay (eg of 15 minutes) between the screening on each successive channel to give the customer a choice of viewing times. It aims to approach the functionality of pure video-on-demand which allows the customer complete control over the time the film is watched.
Network Charge Control (NCC) - The arrangements under C13 of BT=s licence for regulation of BTs interconnection regime.
Network Embedded Services ; services provided by a network operator from within its network with service level advantages over customer premises equipment. Due to the network efficiencies that arise, service providers who are not network operators or owned by network operators would not ordinarily be able to compete in the provision of such services.
Network Futures Group (NFG) - an Industry Committee formed to advise OFTEL and the industry on generic issues associated with interconnection and interoperability.
Network interconnection services - network services that are sold to other network operators.
Network Interoperability Consultative Committee (NICC) ; a committee set up to advise the Director General on interoperability issues and for the industry to provide guidance to standards bodies on such issues.
Networknetwork interface – where two operators networks are interconnected, each must be able to understand the technical operation of the other in order for services to interoperate across the interconnection boundary. The technical characteristics that allow for that understanding is the networknetwork interface. Each network must provide an interface at the point of connection and only where these interfaces are compatible will there be interoperability.
Network number (NN) ; a number allocated by a telephone company which identifies the line from which a call has been made, usually the same as the directory number
Network operator - the operator of a telecommunication network with a Public Telecommunication Operator (PTO) licence, which provides, amongst other things, network services.
Network Provided (NP) number ; a number stored in the network and applied as the CLI of an outgoing call ; it can be either a network or a presentation number
Network Services ; Network Services are services that can only be technically and economically provided by those who build their own telecommunications network infrastructure. BT Network Services (including the elements of these services which are necessarily incidental to the provision of them, like billing customers for the provision of the service) are provided from its Systems Business, whereas Enhanced Services are provided from the Supplemental Services Business. It should be recognised that, notwithstanding the juxtaposition with Enhanced Services, Network Service does not necessarily mean 'simple,' or 'plain old telephone services (POTS).' Network Services may be extremely complex.
Network Termination Point (NTP) ; the edge of a network at which the network is connected to other networks or to terminal apparatus, eg a telephone.
Network Termination and Testing Apparatus (NTTA) ; a piece of apparatus forming part of a public network but situated in a fixed position on customer premises which enables equipment that is not part of a public network to be readily connected to or disconnected from a public network.
New Service - New services are those interconnection services that were introduced after the commencement of the Network Charge Controls ie OFTEL did not set starting charges for the services. BT is free to set charge for new services. However, OFTEL retains the power to subsequently place charge controls on the services.
NFG - see Network Futures Group
NICC - see Network Interoperability Consultative Committee
NGS ; Next Generation Switches.
9-digit/ 10-digit scheme - the number of digits in te numbering scheme following the initial '0' (ie the 9-digit scheme has 10 dialled digits and the 10-digit scheme has 11 dialled digits).
Non Cooperative Service - a non Cooperative Service is a service that requires a specific capability only on the network to which the customer using the service is connected (eg at the local switch) and/or the services economic viability is not dependent on the total number of switches and/or network termination points enabled to originate or receive such a service. Examples of such services are call waiting, three way calling, (simple) call diversion and the speaking clock.
Non-competitive service - BT’s interconnection services that were deemed to be non-competitive at the commencement of the Network Charge Controls in October 1997. Services that were deemed to be non-competitive were placed in one of three charge control baskets ; the interconnection specific basket, the general network basket and the call termination basket ; and each basket was subject to an RPI-8% control for the period 1 October 1997 through to 30 September 2001.
Non-Geographic Number - these are numbers which are used to identify a type of service rather than a geographical location. These services are sometimes referred to as Specially Tariffed Services and include freephone, local rate, national rate and premium rate numbers. Mobile and Personal numbers are aloso non geographic numbers.
Non-Geographic Number Portability ; where a customer who has had allocated to him a non-geographic number associated with a particular type of service, such as 0800 freephone, an 07 personal number, or an 0891 premium rate number, can retain that number when they change to a different operator or service provider offering a service of the same or similar type.
Non-specified ranges - ranges of numbers which are used for purposes which do not comply with the use designated in the Specified Numbering Scheme (eg 0500 numbers uses for freephone services when 080 is the designated range for freephone).
NPRM - Notice on Proposed Rulemaking on International Settlement Rates: because settlement rates in some foreign countries too high they will have to fall under benchmarks of limitations will be put in place. Different rules would apply to different countries.
NTP - see Network Termination Point
NTR - see National Technical Regulation
NTS - see Number Translation Services
NTTA - see Network Termination and Testing Apparatus
Number block ; a means of allocating numbers to network operators who then allocate individual numbers to their customers. The sizes of blocks for the different parts of the Specified Numbering Scheme are identified in the Numbering Conventions.
Number Block Portability - the facility which enables a customer to transfer from one operator to another and retain their number block or, a series of numbers from within a number block.
Numbering Conventions A set of rules and principles relating to the use and management of numbers from the National Numbering Scheme. The Numbering Conventions are published on OFTEL’s Internet pages.
Number mobility - the ability to take a geographic telephone number with you when changing address.
Number portability ; number portability between operators enables a customer to transfer from one operator to a second operator and retain the same number provided the customer remains at the same address.
Number Portability Prefix Codes - codes allocated from the Numbering Scheme used for internal routing of ported numbers, ie, a prefix is attatched to the dialled number which specifies the exchange (operator) to which a number has been ported.
Number translation ; a service where a dialled number is translated to another for final delivery e.g. 0800 numbers.
Number Translation Services (NTS) - the process associated with the routing of a non-geographic number to a network termination point, eg, the number is translated from its non-geographic format into a geographic or mobile number to enable it to be routed to a geographic location or to a mobile phone.
Numbering Code - the initial dialled digits of a telephone number which identify the service.
Numbering Conventions ; the rules by which numbers are allocated.
Numbering Directive - an EU Directive in the course of adoption which creates the EU CPS obligation. The Numbering Directive's provisions will be included as amendments to the interconnection Directive.
Numbering Scheme - a scheme for the allocation and re-allocation of numbers, codes and prefixes. The Numbering Scheme specifies which number ranges are allocated for which type of telephony service which encompasses all public numbering capacity available behind the number ranges 01 to 09, including access and other codes and prefixes.
NVOD - Near Video On Demand
OCB - Outgoing calls barred (OCB) ; used by all operators as an alternative to disconnection of service. If a customer fails to settle their account within a specified time period, the operator will offer OCB with a repayment plan. If a customer defaults on that payment plan, the operator may disconnect the service.
OFT ; The Office of Fair Trading.
OIF ; Oftel Internet Forum.
OLO ; see Other Licensed Operators
OMC ; Operations and Maintenance Centre*
On-Line - where the customer is directly linked via a distribution network to a server thereby enabling him to interact with the server at any time, eg an on-line database giving the customer access when he chooses to data which is being up-dated on a regular basis
One End Breakout - use of the network which involves breakout onto the public telecommunications network only at one end. For example, an operator in the UK could collect traffic on leased lines, switch it to a leased line for onward transit to the destination country, and then break out onto the public telecommunication network there. Alternatively an operator in a foreign country could collect traffic off a private network abroad, and terminate it on the public telecommunications network in the UK.Open access - where a network operator grants access to his network to any service
provider who may reasonably request it.
Open Network Provision (ONP) Committee ; a standing committee of member state national regulatory authorities and others (EC, PTOs and user representatives), which supervises the European Commission's development of the ONP programme. This covers measures aimed at ensuring that services which are not yet required to be liberalised in all member states are regulated in such a way as to guarantee their supply in accordance with certain standards of objectivity, transparency and non-discrimination.
ONP Committee ; The Committee created by Article 9(1) of the ONP Framework Directive.
Open Systems Interconnection (OSI) model - a standard, created by the International Standards Organisation (ISO) in 1983 which classifies data transfer protocols into 7 layers, according to the function they perform, with a view to promoting compatibility between systems. The raw copper loop is below Layer 1 and is described in this document as "Layer 0".
Operator/ Network Operator ; An organisation, generally with its own network, entitled to obtain allocation of numbering capacity from OFTEL. The relevant criteria are identified in the Numbering Conventions.
Operator having significant market power ; a public operator which the Director General has determined to be an operator having significant market power in accordance with regulation 6 (1) of the Regulations; or a systemless service provider which the Director has determined to be an operator having significant market power in accordance with regulation 6(2) of the Regulations.
Operator Services Information System (OSIS) ; a core database run by BT which holds directory information on all BT's customers and customers of other licenced operators. OSIS is used for product databases, eg DAS, and to produce other directory information services and products.
Optical Fibre - cable made of glass fibres through which signals are transmitted as pulses of light. It is a broadband medium that can easily provide capacity for a large number of channels.
Optimal least cost ; Assumes that the user will purchase the cheapest tariff option to suit their particular requirements.
Operator Services Information System (OSIS) - A core database run by BT which holds directory information on all BT's customers and customers of other licensed operators. OSIS is used for product databases, eg Pathfinder, and to produce other directory information services and products.
Optimal least cost ; Assumes that the user will purchase the cheapest tariff option to suit their particular requirements.
Originating network ; the network to which a caller who makes a call is directly connected
Originating operator ; operator on whose network the call originates, ie the operator with the line to the customer.
Originating segment ; the network segment from the school to the first DMSU.
Other Licensed Operators (OLO) - companies, other than BT, which operate telecommunications systems
Outgoing calls barred (OCB) ; used by all operators as an alternative to disconnection of service. If a customer fails to settle their account within a specified time period, the operator will offer OCB with a repayment plan. If a customer defaults on that payment plan, the operator may disconnect the service.
Outpayments ; these are the payments made by one network operator to another for the purpose of conveying messages between the two systems.
Over-ride - the ability of the CPS customer to choose alternative operators to their pre-selected operator(s) on a call-by-call basis.
Own-exchange circuit ; A leased line linking two premises connected to the same local exchange.
PAC - Payphone Access Charge - a charge made by BT to compensate for freephone calls from payphones to cover the costs of running and maintaining BT payphones. It is charged to third parties who use freephone numbers originating on payphones. BT makes a corresponding internal charge. The PAC is referred to in BT=s Carrier Price List as the Public Payphone Supplementary Call Conveyance Charge (PPSCCC)
Packet service - a service involving the transmission of data in the form of discrete blocks (packets) of information and, if necessary, the assembly and disassembly of data in this form.
Parallel running ; when both the old and the new numbering arrangements run alongside each other leading up to an actual number change. It allows customers a transition period to get used to the new arrangements.
Partial private circuit ; BT’s Link to a Point of Interconnection product. This is a private circuit from a customer’s premises to point of interconnection between BT and another operator’s network. It is only available at 2Mbit/s to be purchased by PTOs.
Partial baseband leased circuit ; where a leased circuit extends from one customer to the local exchange and the bandwidth on that circuit extends down to zero Hertz.
Pathfinder ; the BT product database and search engine which will replace DAS and be used to provide an operator assisted directory enquiry service.
Pay-per-view ; the sale or purchase of the right to purchase a single event (eg a boxing match or a film) as distinct from subscribing to a channel or package of channels
Pay-per-view television service ; a television service where the viewer pays to watch a specific event (eg a sporting event, or film). Existing pay-per-view systems require the viewer to ring a customer management centre; impulse pay-per-view systems will enable viewers to purchase the right to see an event using an on-screen menu and their remote control and be authorised immediately.
Pay television ; television services predominantly paid for by the viewer through subscription or other payment for service. This includes subscription television and pay-per-view. See also free-to-air television
Payphone ; a telephone which requires prepayment for calls via coins, calling cards, phonecard, or credit/debit cards.
Payphone licensee- one of two operators with similar rights to PTOs with a licence enabling them to run public call boxes. All PTOs are authorised to run public call boxes.
PC - Personal Computer
PCBs ; Public call boxes.
PCN - Personal Communications Network - high capacity digital cellular networks. (Orange and Mercury 1-2-1 are the current UK PCN operators).
PDA - Personal Digital Assistants
Per operator set-up costs - the costs of enabling CPS for any individual operator, includinbg an activity similar to a data management amendment and the setting up of commercial arrangements for the electronic transfer of customer orders
Per customer line set-up costs - the costs of implementing CPS for a particular customer line
Personal data ; definition used in Data Protection Act 1984 to mean information recorded on computer about living identifiable individuals. Directory information on residential customers and some business customers (partnerships and sole traders) is personal data.
Personal numbers ; a user with a personal number can instruct all calls to that number to be diverted to any other number (including a voice mail box).
Personal numbering - a service based on number translation which enables a customer to be called using a single 'personal' telephone number but to receive those calls at virtually any telephone number in the UK.
Phone Base ; BT’s product database which provides an on-line directory information service. Customers access it using a computer and modem.
PhONEday - 16th April 1995. The date on which all geographic codes were changed by the insertion of a '1' following the initial dialled '0' (ie they became '01.....')
Phone Disc ; BT’s directory CD-ROM product which contains residential and business directory information on all customers listed in phone books.
Phone Subsidy ; Difference between the retail price of the phone and the cost of the phone.
(PIN) - Personal identification number.
Points of Connection (POC) ; also known as a Switch Connections ie where an operator’s network interconnects with BT usually at a Digital Main Switching Unit (DMSU) or Wide Area Tandem (WAT). Points of connection with BT in the context of OFTEL’s Direction of BT’s NTS Conveyance refer only to switch connections carrying NTS calls where the links were ordered by the operator and agreed with BT according to forecasts of capacity requirements provided by the operator. The operator will also have paid any appropriate charges. Circuits provided by BT for its own network management purposes, referred to as NTS Extension Circuits (NTSECs), do not qualify as they are not a BT standard interconnection product. These are distinct from Interconnection Extension Circuits (IECs) which are a BT Standard Service.
Porting, Ported - keeping the same number when transferring from one operator to another.
Pre-pay package ; After paying a one-off fee for the phone and connection, the user buys vouchers which enable them to use the phone.
Predatory pricing/predatory behaviour ; a firm deliberately sacrificing short-run profits in order to weaken competitors or drive them out of the market enabling it to earn monopoly rents in the longer term by sustaining prices (and therefore profits) at a level higher than would otherwise obtain in a competitive market
Premium Rate Service (PRS) ; services, including recorded information and live conversation, run by independent service providers. All calls to these companies are charged at a higher rate than ordinary calls to cover the companies' costs in providing the content of the call and the operator's cost for the special network facilities needed.
Premium channels ; traditionally the term premium channels has been used to describe channels which viewers subscribed to as an add-on to the basic service and for which they paid a premium
Premium programming ; is characterised by consumers’ relatively high willingness to pay; limited supply and time-criticality. Premium programming may be seen as covering a spectrum. At the extreme there is Premier League football where there is a high degree of time-criticality, limited supply and high willingness to pay. Other premium programming may have these characteristics to a lesser degree. Premium programming is the core component of premium channels
Presentation number ; a number chosen by a caller to which return calls may be made
PRI - Primary Rate Interface
Price discrimination - supplying the same product/service to different customers at different prices in relation to differences in costs. Conventional price discrimination is possible where the supplier is able to segment the market, either on the basis of (known) different demand characteristics, or by a self-selecting set of volume related tariffs.
Price floor ; the level which BT must price at or above if its prices are not to be regarded as anti-competitive.
Pricing signals ; the information about demand, costs and quality etc contained in relative prices or changes in relative prices.
Prior Year Revenue Waiting - The basket weight for BT’s price and charge controls have been set equal to the proportions of basket revenue accruing to the relevant services in the year before that in which the price changes take place.
Prioritised circuit bumping - displacement of lower priority information being carried by a circuit with information of a higher priority.
Private circuits - (also known as leased circuits) point-to-point circuits for customers exclusive use covering speech, data or image communications.
Private networks - a telecommunications network on the customer=s side of a network termination point, which forms the boundary between a public telecommunication system run under a PTO licence and the user=s network, generally run under a Class Licence. At its simplest, a private network may consist of just one handset and a length of wiring.
Private payphones ; a payphone operated under a class licence, where the service offered is ancillary to the main activity or service being offered.
Product database ; term to describe databases which are produced by downloading directory information from core databases and manipulating that information so that it is suitable for various types of interrogation. DAS is an example of a product database.
Proportionate return ; An arrangement by which incoming traffic from the far end country is distributed among the near end country's operators in proportion to the outbound traffic sent by them to the far end country. Under the international facilities licences (and in Mercury's licence), there is a requirement on operators for a form of proportionate return whereby the share of incoming traffic they receive on a route is no greater than the share of outgoing traffic that they send.
Prospectively competitive service - BT’s interconnection services that were deemed to be prospectively competitive at the commencement of the Network Charge Controls. Services that were deemed to be prospectively competitive were not competitive at the commencement of the Network Charge Controls but were expected to become competitive before the end of September 2001. Charges for these services were subject to an individual (RPI+0%) safeguard cap.
Protocol conversion - protocols are sets of rules that govern the exchanges between two telecommunication systems for the purpose of transferring information (signalling or data). Protocol conversion is where one set of rules is converted to another set of rules, to enable entities using different rules to exchange information.
PRS - see Premium Rate Service
PSTN ; Public Switched Telephony Network.
PTO - Public Telecommunications Operator - network operators providing services to the public with powers granted by the Secretary of State for Trade and Industry under the Telecommunications Act 1984 to enable them to install their systems on public and private land, property etc.
Public Call Box (PCB) ; a payphone to which the public has unrestricted 24 hour access and which is operated under an individual company licence.
Public operator ; A person to whom a licence has been granted under section 7 of the Telecommunications Act 1984 authorising the running of a public telephone system and the provision of publicly available telephone services.
Public Payphone Supplementary Conveyance Charge (PPSCC) - (also known as Payphone Access Charge PA) an additional charge paid by indirect access operators to BT to cover the costs of providing and maintaining call boxes and for the use of the exchange line (normally covered by line rental).
Public Switched Telephone Network - PSTN - the telecommunications networks of the major operators, on which calls can be made to all customers of all PSTNs.
Public telecommunications network ; a telecommunications network used, in whole or in part, for the provision of publicly available telecommunications services
Public Telecommunications Operator - network operators providing services to the public with powers granted by the Secretary of State for Trade and Industry under the Telecommunications Act 1984 to enable them to install their systems on public and private land, property etc.
Public telephone system ; Telecommunication system forming part of the fixed public telephone network (or a mobile public telephone network).
Publicly available telecommunications services - whether a service is "publicly available" is likely to be a question of fact and judgement which will depend on all the circumstances. As a minimum it is likely that a telecommunication service will be publicly available if it is "on offer" to anyone who is prepared to pay for it, probably with standard terms and conditions. Sometimes this criterion may not be sufficient. Public accessibility of the network over which the service is provided may also need to be taken into account.
QMNC (Qualifying Multinational Corporate Customers) - selected multinational customers meeting cdrtain criteria and eligible to be direct customers of the joint venture
RA ; The Radiocommunications Agency.
Radio fixed access ; Technology that enables operators to provide customers with direct connection to the public telecommunications’ network via a fixed radio link from the home or premises to the local exchange, instead of providing a ‘wired’ connection using copper cables or optical fibre.
Radio in Local Loop -the technical approach of providing customer connection to the public network via a fixed radio link from the home or premises to the local exchange, instead of providing a "wired" connection using copper cables or optical fibre.
Radio Spectrum ; the range of wavelengths used, for example, for broadcasting radio, terrestrial television and satellite television. Usable wavelength ranges from about 100 KHz to about 400 GHz although there are as yet no broadcasts above about 12 Ghz.
Raw directory information ; this term is used to describe the directory information that each telecommunications company collects on its customers. It is distinct from directory information aggregated from several telecommunications companies which is supplied from core databases.
Recipient Operator ; An operator to whom customer number (s) are in the process of being, or have been passed or ported from a Donor Operator.
Regulated Supplier: a supplier of Access Control services that has been determined by the Director to be a Regulated Supplier (the determination will be based on finding that the firm in question is dominant or has Market Influence in the relevant intermediate market within which the Access Control services it supplies fall).
Relevant Connectable System (RCS) - (applicable to December 1997) defined in BT=s licence and other PTO licences. In essence, and with certain exceptions, it means a telecommunication system run under an individual licence, authorised for connection to the PSTN , and authorised to provide services which have been or are to be conveyed over the PSTN, for reward to the public. BT is required to provide network services to operators with RCS status at its licence condition 13 prices (ie essentially Acost plus@).
Relevant end-user market: the generic term used when referring to the relevant market within which the digital services requiring Access Control services fall. Depending on the digital services in question the relevant end-user market may include non-digital services and digital services not requiring Access Control service.
Reference Interconnection Offer (RIO)- the terms and conditions for interconnection offered by operators with SMP status for the purpose of the Interconnection Directive.
The Regulations ; The Telecommunications (Open Network Provision) (Voice Telephony) Regulations 1998.
Relevant intermediate market: the generic term used when referring to the relevant market within which the Access Control services fall; it recognises that Access Control services are not supplied directly to end-users but are supplied to third parties who wish to supply digital services to end-users.
Relevant Numbering Condition ; condition 34B of BT's licence and the equivalent condition in those of other operators.
Residential Limited Service Scheme (RLSS) ; a BT product required under its licence which provides a low cost telephony service. It allows only incoming calls and a limited range of outgoing calls such as those to the emergency services.
Retail IDD ; Retail International Direct Dialled calls are calls made by end-users dialling direct to subscribers in other countries.
Retail Minus ; means the price charged by the Licensee for the provision of a service to end users less any elements of cost that are not incurred in providing the same service to a Relevant Mobile Operator.
Return path - the means by which messages are transmitted back through, for example, a cable TV or telephony system from the customer to the provider of a service. It is the means by which interactivity can be achieved.
Return on Capital Employed (ROCE) ; the ratio of accounting profit to capital employed. The measure of capital employed can be either HCA or CCA.
Reverse search directory ; such a directory would enable searches by telephone number and/or address.
Revised Voice Telephony Directive (RVTD) - the European Parliament and Council Directive of 26th February 1998 on the Application of Open Network Provision (ONP) to Voice Telephony and on Universal Service for Telecommunications in a competitive Environment (98/10/EC) implemented by the Telecommunications (Open Network Provision) (Voice Telephony) regulations, 1998 (1998, No.1580). This Directive concerns the universal provision of voice telephony services. The Directive leads to a number of additional obligations on operators as well as setting out various rights for consumers.
Ring Back When Free ; a Network Service enabling a caller who has attempted to make a call to a number that is engaged to be alerted by the network when that number becomes available for connection.
RIO (Reference Interconnection Offer) - The Telecommunications (Interconnection) Regulations 1997 require BT to publish a RIO which should include a description of the interconnection offerings broken down into components according to market needs and specify the charges and other terms and conditions on which they are offered.
RLSS - see Residential Limited Service Scheme
RNIB ; The Royal National Institute for the Blind.
RNID ; The Royal National Institute for Deaf People.
Roaming ; ‘National Roaming’ means the provision of Connection Services by means of the Applicable Systems to Authorised Mobiles in respect of Teleservices and Bearer Services pursuant to a National Roaming Agreement between the Licensee and a Relevant Mobile Operator.
Rollover - A proposal made by OFTEL in its consultation document Rollover of existing retail price and network charge controls. This proposal would enable the present network charge and retail price controls to continue in force for a period of 8 and 6 months respectively in the event that BT and OFTEL could not reach agreement over proposals for a new price and/or charge control, should either be required.
RPI ; Retail Price Index.
RPI - X the system of price control where average annual price changes for the price-controlled services are limited to the increase in inflation (as measured by the Retail Price Index) less a specified number (X).
RVTD - see Revised Voice Telephony Directive
SB - see Systems Business
Scrambling - the act of encoding a signal (eg a TV programme) so that it can only be accessed by those customers with the necessary decoding equipment.
SDH - see Synchronous Digital Hierarchy
SDR - see Special Drawing Rate
Second Generation (2G) ; 2G means spectrum within the 880;915 MHz, 925;960 MHz, 1710;1785 MHz or 1805;1880 MHz bands
Selective Call Barring - the ability to programme a Public Switched Network access line, so that outgoing calls to certain related groups of numbers such as special charge rate, international or mobile services cannot be made.
Self correspondence ; If a telecommunications company has a licence to operate international facilities at both ends of a route, it may be able to originate and terminate calls on the route at both ends . This can obviate the need for a correspondent agreement.
Self Provided Telecommunications Systems Licence (SPL) - a class licence which allows the Licensee to provide its own links over any distance rather than leasing from an operator. All traffic must originate and terminate with the licensee or its Group and no financial benefit other than the reimbursement of costs, may be received for the provision of telecommunication services.
Self- regulation: Stakeholders ( industry, consumer groups and others) take the initiative to co-operate for the benefit of consumers. Regulator's role as observer (if any)
Service provider ; provider of telecommunication services, or services with a telecommunication service component, to third parties whether over its own network or otherwise.
Set top convertor - equipment which acts as the interface between the network and the TV set.
Settlement rate ; usually (but see TEURIM) half the accounting rate, and the amount of money (in SDRs) per traffic minute actually paid by one party if international traffic is not in balance (i.e. if traffic flow one direction is more than in the other).
Shared access ; an arrangement where two operators provide services over the same loop. One of the operators will be employing the lower frequency portion of the loop to provide voice telephony and the other will be using the higher frequencies to provide high-speed data services.
Shared loop ; the access network connection between the customer’s premises and the local PSTN exchange, usually a loop comprised by two copper wires, on which two operators provide services. One of the operators will be employing the lower frequency portion of the loop to provide voice telephony and the other will be using the higher-frequencies to provide high-speed data services.
Sidecar channel ; a channel which is sold as an adjunct to a premium channel in order to carry more than one event simultaneously (eg two sporting events).
Signalling Point Codes - codes used by operators for internal routing purposes, ie, to enable telephone switches to identify one another when routing calls over telecommunications networks.
Signalling System No7 - the common channel signalling system used by almost all UK public networks to carry call and circuit control signals between public exchanges. Often referred to as the CCITT No7 or C7 signalling system.
Significant Market Power (SMP) - The Significant Market Power test is set out in various European Directives, including the Interconnection Directive, the Amending Leased Lines Directive and the Revised Voice Telephony Directive. It is used by the National Regulatory Authorities (NRA) such as OFTEL to identify those operators who must meet additional obligations under the relevant directive. It is not an economic test, rather it requires a consideration of the factors set out in the test within a specified market.
SIM ; Subscriber Identity Module
Single tandem conveyance - a BT service provided to interconnect network operators whereby a call passed on to BT's network at a "tandem exchange" (ie one that routes calls between exchanges but not having direct connections to end users) is passed on to a local exchange and then on to the end user.
Single transit - Interconnection service that involves the use of one switch (deemed to be a tandem switch) but no transmission.
Sites in multiple occupation - are defined as sites where BT has contractual commitments for network services to more than one customer.
Sites in single occupation - sites in single occupancy where BT has only one set of contracts with one customer for network services to that customer on that site.
Slamming - the practice of changing a customer's pre-selected carrier without their express permission.
SMATV - Satellite master antenna television. A narrowband local television-only system operating under a class licence.
SMDS - Switched multi-megabit data service - a public switched broadband data service providing inter-site connectivity of, for example, Local Area Networks (LANs), and mainframe computers, at multi-megabit speeds (ie faster than available with Frame Relay).
SME - Small and Medium Enterprise
SMP - see Significant Market Power
SN - Subscriber number - the number to be dialled to reach a customer in the same local network or numbering area. This is the number usually listed in a directory against the name of that customer
SOGIS - Senior Officers Government Information Security (Digital Signatures Directive is context)
Special arrangement ; an agreement between a subscriber and a public network operator whereby the subscriber undertakes to provide for CLI display purposes only authentic calling party numbers which are not checked by the public network
Special Drawing Rate – the accounting unit used for charging for international traffic. 1 SDR is approximately UK£0.84, ?1.19, US$1.41.
Special or exclusive rights ; the rights granted by a Member State or a public authority to one or more public or private bodies through any legal, regulatory or administrative instrument reserving them the right to provide a service or undertake an activity in a particular geographic market, otherwise than according to objective, proportionate and non-discriminatory criteria.
Specified Numbering Scheme ; a scheme for the allocation and reallocation of numbers which is specified by the Director General and made available by him for public inspection.
Spectral management - managing the type and quantity of devices connected to the copper pairs, through analysing the impacts of the power and frequencies transmitted, so as to eliminate, as far as possible, any unwanted interference between services on the cable; and between those services and external radio services. Also, to optimise the effective use of technologies to deliver the maximum overall benefit from the cable concerned, for example, by deploying a higher density of lower capacity devices compared to a lower density of higher capacity devices.
SPL - see Self Provided Telecommunications Systems Licence
Splitter ; a device which separates a local loop into two independent channels, so that different services can be run on it without interference
SSB - see Supplemental Services Business
Stand alone costs ; the costs to a single product firm of providing a service. The stand-alone costs of a service exceed the incremental costs to a multi-product firm if there are economies of scope.
Standard Service ; an interconnection service which BT is required to provide under Condition 13 of its licence.
Sterilisation (period) ; The period of time, following withdrawal, during which a number is not allocated or used for another purpose in order to minimise the potential for mis-dialling and mis-routing of calls
STP ; Signalling Transfer Point ; A facility whereby C7 signalling messages can be passed between exchanges without requiring a discrete circuit between them.
Tandem switch ; Main exchange in the core
Subscriber ; A person who is party to a contract with the provider of publicly available telecommunications services for the supply of such services.
Subscription television service ; a television service which is purchased by subscription (as opposed to pay-per-view or free-to-air). Subscription television services are usually classified into a basic tier of general news and entertainment channels and premium services (sports and films).
Substitutability ; whether an increase in the price of one product would lead consumers to switch to other competing products or services (demand-side substitutability) or lead producers to switch rapidly into the supply of the good in question (supply-side substitutability)
Sunk ; costs which are not recoverable if the activity for which they were incurred ceases.
Supplemental Services Business (SSB) - currently defined in BT's licence by reference to the 1987 Value Added and Data Services Class Licence. In essence, and under the current definition, it means that part of BT's business that provides all telecommunication services or enhanced services except "live speech and telex" (which are in BT's Systems Business).
Switchless Resellers ; Service Providers who do not have their own network.
Switched - relates to a telecommunications network comprising at least one exchange and capable of routing signals and messages from one line to all other lines comprised in the network.
System ; the computers and associated software and software interfaces which provide the facilities and arrangements for enabling transactions etc.
Systems Business (SB) ; currently defined in BT's licence as being, essentially, that part of BT's business involving the installation, running and maintenance of its network and the conveyance of live speech and telex messages, as distinct from the Supplemental Services Business.
Systemless Service Providers ; as defined in the RVTD Regulations to mean a person who provides publicly available telephone services but who does not run a telecommunications system within the meaning of Section 4 of the Telecommunications Act 1984 by means of which such services are provided.
System set-up costs - the costs of developing and implementing on switches the software neede for the capability tp provide CPS, and the cost of modifying support systems.
Synchronous Digital Hierarchy (SDH) ; a method of telephony transmission using digital techniques where the data is packed in containers which are synchronised in time enabling relatively simple modulation and demodulation at the transmitting and receiving ends. The technique is used to carry high capacity voice circuits over long distances.
TACS - Telecommunications Advisory Committees - independent regional advisory bodies set up by OFTEL.
Tandem ; A main exchange in BT’s network which acts as a single switching point for calls.
TDAB - Terrestrial Digital Video Broadcasting
TDVB - Terrestrial Digital Video Broadcasting
Telecommunications ; conveyance of speech, music and other sounds, visual images or signals by electric, magnetic, electro-magnetic, electro-chemical or electro-mechanical means.
Telecommunications Act ; The Telecommunications Act 1984
Telecommunications Data Protection Directive ; the European Parliament and Council Directive of 15 December 1997 concerning the Processing of Personal Data and the Protection of Privacy in the Telecommunications Sector (97/66/EC)
Telecommunications network ; transmission systems and, where applicable, switching equipment and other resources which permit the conveyance of signals between defined termination points by wire, by radio, by optical or by other electromagnetic means.
Telecommunications Regulations Application Committee - an organisation originally set up by members of the European Conference of Postal and Telecommunications Administrations (CEPT), now acting as a two-way intermediary between the Commission and ETSI on aspects of the Telecommunications Terminal Equipment Directive.
Telecommunications Services Licence (TSL) – a class licence under which individuals can offer certain telecommunications services including a private payphone service. The licence authorises the connection of up to 20 sites by self-provided lines, or an unlimited number by leased lines.
Telephone Preference Service (TPS) ; a service established by the Direct Marketing Association to help reduce the number of unwanted telemarketing calls received by customers. Customers contact their telephone company to join and their details are then removed from lists used by many companies engaged in
Telecommunications Users= Association (TUA) – represents all categories of user from large business to residential
Telecommunications Act ; The Telecommunications Act 1984
Teleservices ; are telecommunication services which provide the user with the necessary capacities including terminal equipment functions, to communicate with any other users and cover speech, short message service and facsimile services
Television on-demand - also known as video-on-demand. A programme or film sent independently to a customer in response to his individual request. This contrasts with broadcast television which is sent simultaneously to all customers able to receive it.
Temporary Call Box ; call box installed for a limited time often to cater for a special event
Terminating network ; the network to which a customer who receives a call is directly connected.
Terminal portability - the ability for customers to transfer their terminal apparatus (eg a telephone) to another public network without any loss of interoperability.
Terminating operator ; the operator on whose network the call terminates.
Terminating segment ; the network segment from the second DMSU to the concentrator where it is assumed the Internet/on-line service providers interconnects, excluding conveyance between the first DMSU and the second DMSU and the costs of the second DMSU which forms the transit segment.
TETRA - Terrestrial Trunked Radio, a modern digital Private Mobile Radio technology
TEURIM ; the asymmetric accounting rate system used in Europe and the Mediterranean, where the lack of symmetry is intended to reflect the differing cost elements in each country.
Textphone ; a device used by hearing and speech impaired people to communicate over networks in typed text rather than speech (ie the device is needed at both ends of the call).
Text relay ; a service enabling textphone users to communicate via the network with other customers by means of an on-line translation service.
Text users rebate scheme ; a scheme whereby textphone users receive a refund on phone call charges because, on a like for like basis, text calls take longer to make than voice calls.
Third generation (3G) ; means, for the purposes of this Condition spectrum within the 1900;1980 MHz, 2110;2170 MHz.
Third generation auction ; The auction for radio spectrum in the 2 GHz band at 1900;1980 MHz, 2110;2170 MHz
Third generation mobile systems ; A European 3G mobile communications system will provide an enhanced range of multimedia services (eg high speed Internet access). 3G networks are expected to enter service in 2002/3 using radio spectrum in the 2GHz bands.
Third party: a firm that wishes to provide end-users with a digital service in respect of which the use of Access Control services is necessary. Third parties could be retailers or banks, for example.
TIC - Technologies of Information and Communication
Time of day routing - the routing of calls to different destinations depending on the time of day or the day of the week, according to instructions held in the network that relate to a particular customer. For example, an organisation may wish to advertise a single telephone number but have incoming calls directed to different locations at different times. Such routing usually requires use of a number translation service.
TMA – Telecoms Managers Association large business telecoms users’ organisation
TDPD Regulations ; the proposed Telecommunications (Data Protection and Privacy) Regulations 1999 which will implement the Telecommunications Data Protection Directive.
TDPD Direct Marketing Regulations ; the Telecommunications (Data Protection and Privacy)(Direct Marketing) Regulations 1998 which implement the direct marketing provisions of the Telecommunications Data Protection Directive.
TPS - see Telephone Preference Service
TRAC - see Telecommunications Regulations Application Committee
Transcontrol ; the process of converting digital television services from the format provided by on broadcaster into a format such that it can be re-transmitted by another broadcaster.
Transfer Charges ; the charges made by one part of a firm for services provided to another part (eg BT Network to BT Retail).
Transit; A transit service is a conveyance service provided by a network between two points of interconnection. It is, therefore, a service that links two networks that are not in themselves interconnected.
Transit network ; a network through which a call passes, but which is neither the originating network nor the terminating network for that call.
Transit segment ; the network segment from the first DMSU to the second DMSU, including the conveyance costs and the costs of the second DMSU.
Transit service ; a conveyance service provided by a network between two points of interconnection. It is, therefore, a service that links two networks that are not in themselves interconnected.
Tromboning ; sending traffic which comes from a fixed and is destined for a mobile network in the same country via a second country to take advantage of beneficial accounting rates for termination of international traffic on mobile networks
Trunk network - that part of a telecommunications network which provides connections between customer-serving exchanges.
Trunk segment ; A trunk segment is capacity between the serving centres for leased lines at trunk exchanges, that is between any of BT’s DMSU centres used for routing leased lines.
TSL - see Telecommunications Services Licence
Tied Service Provider (TSP) ; service providers which are owned by or in common ownership with the network operator’s Group.
TUA ; see Telecommunications Users’ Association
Two-part Charging - Separate charges for call set up and for maintaining the connection of the call. The former charge would be levied on a per call basis, while the latter would be levied on a per minute basis
Typetalk ; a special unit of the RNID funded by BT responsible for delivering a text relay service.
UMTS ; Universal Mobile Telecommunications System ; so called 3rd generation mobile communications system which will provide enhanced range of multimedia services (eg video, high speed internet access).
Universal Service (US) ; a provision in some Telecommunications Act licences requiring the licensee to provide certain services to all specified persons. For example, BT is currently required to provide basic voice telephony and certain other established telecommunications services to anyone who may reasonably request them.
Universal Service ; the basic level of telecommunications services which should be available to all customers.
Universal Service Obligation (USO) ; A provision in some Telecommunications Act licences requiring the licensee to provide certain services to all specified persons. For example, BT is currently required to provide basic voice telephony and certain other established telecommunications services to anyone who may reasonably request them
Universal Service Provider - BT and, in Hull, Kingston Communications, who have certain licence obligations designed to ensure that a basic level of telephony service is available to everyone in the licensed area upon request
UPNV (User Provided, Not Verified) number ; a number that is supplied by a user which identifies a NTP and has not been subjected to screening or editing by the network.
UPVP (User Provided, Verified and Passed) number ; a number whose most significant part is network provided and whose least significant part is supplied by a user and successfully checked by the network for length and range
User ; A person using or requesting publicly available telecommunications services.
Usage pattern ; See user profile.
User profile ; Describes how a particular customer or group of customers use their phone in terms of usage (number of minutes per month), time of day and/or destination number (ie national, international, calls to mobile etc.)
Universal Service Obligation (USO) - A provision in some Telecommunications Act licences requiring the licensee to provide certain services to all specified persons. For example, BT is currently required to provide basic voice telephony and certain other established telecommunications services to anyone who may reasonably request them.
UXD5 exchange ; a small digital rural exchange used in parts of Wales and Scotland, which has limited facilities.
VANS - Value Added Network Services
VAS - Value Added Sevices
Vertical Integration ; where a single company is active in more than one stage in the production and supply of a good or service eg where a network operator also provides enhanced services which are carried over the network or supplies the consumer equipment needed to access services it provides.
Vertical integration ; where a single company is active in more than one stage in the production and supply of a good or service eg where a network operator also provides enhanced services which are carried over the network or supplies the consumer equipment needed to access services it provides.
Video-on-demand - See television on-demand.
Video-phone - a specially adapted or designed telephone that enables the called and calling parties to see each other during the call.
Videotex - a service allowing specially adapted televisions to display text-based information retrieved from a central database via the PSTN.
Virtual Text Node (VTN) ; A proposed network service being prepared by BT which would enable textphone calls to be handled more efficiently and would increase the speed and efficiency of text relay services.
VLR ; Visitor Location Register
Voice mail ; facility to leave a voice message which can be accessed from different locations.
Voice telephony service ; a service available to the public for the commercial provision of direct transport of real-time speech via the public switched network or networks such that any user can use equipment connected to a network termination point at a fixed location to communicate with another user of equipment connected to another termination point.
VPN – Virtual Private Network these are used by a company or private group to make inter-site connections either for telephone speech or data as if there were dedicated leased lines between these sites. The equipment used is located within the public telecommunications operators’ premises and forms an integral part of the public network but is software- partitioned to allow for a genuinely private network
VSAT - Very Small Aperture Terminal, digital satellite data network with small antenna diameter
Virtual Text Network – a BT network product currently in development which would enable textphone users to make greater and more efficient use of text relay services and the network generally.
WANS - Wide area networks ; a network allowing the interconnection and intercommunication of a group of computers over a long distance
WAP - Wireless Application Protocol
WAP Forum - An industry association with over 500 members which develop the open standards designed to optimise web content on mobile devices such as Mobile phones, PDAs, and pagers
WAP Gateway - Accesses web content for the mobile, in theory capable of converting HTML to WML, but much of the content accessed from WAP Gateways has already been specially authored in WML.
W-CDMA - Wideband Code Division Multiple Access
Well Established Operator (WEO) - A concept previously used in licences, but which has now been replaced by the concept of Market Influence.
WEO - Well Established Operator - a regulatory concept applied in the context of specific product markets. A WEO is an operator with 25% or more of what is in the opinion of the Director General the relevant market, unless the Director General determines that the operator is not a WEO, or an operator with less than 25% of what is in the opinion of the Director General the relevant market which is determined by the Director General to be a WEO.
Wholesale IDD ; Wholesale International Direct Dial is where one operator supplies IDD services through an interconnect arrangement to other operators for onward supply to retail customers.
Wholesale interactive services ; the ability to offer retail goods and services to the end customer rather than the goods or services themselves.
Wholesale service provider ; the organisation which provides the computer servers, needed for the playout of video and data and the reception and processing of responses from consumers via modem. The wholesale service provider might also provide other services to retailers and retail service providers such as design and writing applications.
Wideband ; an intermediate bandwidth without the fuller capacity of broadband
Windows CE - Windows for PDAs
Withheld ; where a caller has chosen not to allow a CLI to be presented to the person being called
WML - Wireless Markup Language
WT Act - The Wireless Telegraphy Acts 1949 to 1998
World Trade Organisation (WTO) - International body that deals with the trade between countries. The WTO provides the legal framework for international commerce.
WTO Agreement on Basic Telecommunications Services - The WTO Global Agreement on Trade in Basic Telecommunications Services (known as the Fourth Protocol to the General Agreement on Trade in Services) came into force in February 1998. The agreement provides a framework for the gradual liberalisation of market access and also establishes a framework of basic regulatory principles (such as measures to prevent anti-competitive behaviour and non-discriminatory and timely provision of interconnection and cost-oriented rates).
X.25 service - a widely available, low speed, packet switched data service (see packet service), operating at speeds below those offered by Frame Relay.