A

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 (eg 192 for directory enquiries) or to select a choice of carrier.

Access Control Services – services which control the supply to end users of digital services other than digital television services and certain other specific exclusions. Access Control Services are not supplied directly to end users but are supplied to third parties (for instance, retailers or banks) who wish to supply digital services to end users. Examples of Access Control Services include services for authenticating identity and services for encrypting or decrypting digital services that are not intended to be available to all.

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

Add Drop multiplexor (ADM) - Multiplexor equipment enabling enabling the removal or addition of bit-streams from larger assemblies

Advance contract package – A package which includes the phone, connection, a year’s line rental and, in some cases, some inclusive call minutes.

Allocation Certificate - A certificate issued by Oftel to operators showing the numbering allocated to them and signed by an Oftel employee who is authorised to do so the Director General of Telecommunications.

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 thier 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.

ASR (Answer Seizure Ratio) - the number of calls, having left the outgoing side of the exchange, that have been successful in returning an answer signal.

ADSL (Asymmetric Digital Subscriber Line): a digital technology that allows the use of a copper line to send a large quantity of data in one direction and a lesser quantity 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. 

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B

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 greater than 128kbit/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

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C

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 modem: a cable modem is a device that enables a consumer to access the Internet via a cable line

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.

Channels: an exchange line consists of one or a number of channels, each having a bandwidth of 64 kbit/s.

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'.

Combinatorial test: a test to be applied on a combination of services where there are common costs between services. The revenue from any combination of services would need to cover the common costs between the services as well as the incremental cost of each service.

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.

Communications provider: a person who provides an Electronic Communications Network or provides an Electronic Communications Service.

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. Any natural person who uses a Publicly Available Telephone Service for purposes which are outside his trade, business or profession. The term therefore excludes business users and corporate customers generally.

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 Volume Ratio (CVR)- the relationship between movements in volumes of say call minutes with the underlying cost of provision

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.

Customer Sited Handover (CSH) - Interconnection occurs at an OLO's premises

CVR (Cost Volume Ratio): the relationship between movements in volumes of say call minutes with the underlying cost of provision

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D

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 Enhanced Cordless Telecommunications

DECT Handsets (Digital Enhanced Cordless Telecommunications) – cordless handsets for domestic and business use.

Dedicated port: A connection, typically on a Network Access Server or telephone exchange, which is reserved for use by a single (wholesale) customer, for example an ISP.

Detailed Attribution Methods Enhanced (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.

Dial-up Internet access: Internet access that uses a dial-up connection over an analogue or ISDN telephone line.

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 Cross Connection Node (DCCN) - a node in BT's Private Circuit Network where circuits at 64 kbit/s and below can be cross connected between differing 2 MBit/s tributaries

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, often via a remote concentrator unit.

Digital Main Switching Unit (DMSU) – a trunk exchange primarily used for connecting long distance calls.

DSL (Digital Subscriber Line): 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.

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's network by a fixed link

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

DLE FRIACO: Digital Local Exchange FRIACO - The provision of Flat Rate Internet Access Call Origination via a wholesale unmetered Internet access product from BT at the local exchange.

DMA – Direct Marketing Association.

Digital Main Switching Unit (DMSU) - a tandem exchange primarily used for connecting calls between DLEs.

Digital Subscriber Loop Access Multiplexer - see DSLAM

DQ Numbering Sub-Group - A group set up by Oftel to act as the Industry forum for advising the Director General of Telecommunications of the Industry-preferred methods of allocating 118 codes for DQ services. The Sub-Group comprises Oftel and operators running a public telecommunication system under a licence granted under Section 7 of the Telecommunications Act 1984, whether that is an individual or a class licence, containing a Numbering Arrangements Condition, or those operators who are in the process of applying for such a licence.

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

DSL- see Digital Subscriber Loop

DSL technology – digital subscriber line technology.

DSLAM (Digital Subscriber Loop Access Multiplexer): apparatus sited in the same exchange building as is used to terminate DSL enabled copper loops, which comprises a bank of DSL modems and a multiplexer which combines many customer lines into one data path.

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)

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E

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

Exchange line - the telephone line that connects the customers' network terminating point to the local exchange.

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

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F

FAC - see Fully Allocated Costs

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.

Fully Allocated Cost (FAC) - An accounting approach under which all the costs of the company are distributed between its various products and services. The fully allocated cost of a product or service may therefore include some common costs that are not directly attributable to the service.

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.

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 .

Fully Allocated Costs (FAC) - an accounting method for attributing all the costs of the company to defined activities such as products and services. Typically this method would follow the principle of cost causality.

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G

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.

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H

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.

HDSL (High data rate Digital Subscriber Line): one of the earliest forms of DSL services to be widely used. It is symmetrical, offering the same data rates upstream and downstream. The maximum data rate is however lower than that for ADSL.

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.

Hull Area - the area defined as the 'Licensed Area' in the licence granted on 30 November 1987 by the Secretary of State under section 7 of the Telecommunications Act 1984 to Kingston upon Hull City Council and Kingston Communications (Hull) plc

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I

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 – Interconnect Call Accounting system. BT's system used for accounting and billing for interconnect calls to third parties.

In Contact – the name which BT uses to market its Residential Limited Service Scheme.

In Span Handover (ISH) – Interconnection occurs at a point between BT’s premises and an OLO’s premises

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) - a company that provides individuals and other companies access to the Internet and other related services.

Indirect access – where a customer establishes a connection with a particular operator's network by dialling a short code to switch through the network on which his exchange line terminates. Such calls are usually billed by the Indirect Access operator.

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 evolved from the digital PSTN which provides digital exchange lines to customers and 64kbps end to end digital connectivity between them. Two or more 64kbps connections can be combined to provide a higher speed connection, eg 128kbps..

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 linking (whether directly or indirectly by physical or logical means, or by a combination of physical or logical means) of one Public Electronic Communications Network to another for the purpose of enabling the persons using one of them to be able:
(a) to communicate with users of the other one; or
(b) to make use of services provided by means of the other one (whether by the provider of that Network or by another person);

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 connectivity: the ability to access any destination on the Internet from a point of interconnection with an Internet backbone.

Internet service provider – a service provider who provides access to Internet services.

Internet telephony - a specific type of VoIP service that uses the public Internet to carry the IP traffic (also referred to as Voice over the Internet)

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 - the packet data protocol used for routing and carriage of messages across the Internet and similar networks.

IP network - a network that uses IP; for example the Internet is a public IP network.

IPF - see Interconnect Policy Forum

IPLC - International Private Leased Circuit – an international leased line.

IP Telephony - see VoIP

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

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J

JV - Joint Venture

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K

Kbps (Kilo (thousand) bits per second) - a measure of the speed of transfer of digital information.

Kingston – Kingston Communications (Hull) PLC – telephone company which operates in the Hull area.

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L

LEO - Low Earth Orbit

LANS (Local area networks )– 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)

LDO (Local Delivery Operator) - 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 permanently connected communications link between two premises dedicated