(words in italics indicate cross-references to other definitions)
Accounting Separation
The preparation of separate accounts for different businesses run by the same company, so that the costs and revenues associated with each business (and transfers between them) can be separately identified and properly allocated.
Asynchronous transfer mode (ATM)
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.
Asymmetric digital subscriber loop (ADSL)
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.
Backhaul transmission
A vision circuit used for the transmission of broadcast services, linking a studio to a satellite earth station for onward transmission via satellite (uplinking) for direct broadcasting to, for example, the home.
Basic retail services
See the description in Chapter 1, paragraph 1.11. Services provided generally by a network operator, consisting of end-to-end network services and the retail elements involved in serving a customer, for example, sales and marketing, billing and customer service.
BT Retail Systems Business
That part of BT's Systems Business which obtains network services from BT Network Business in order to sell basic retail services to customers, whether that customer is an end user, an independent service provider or BT's Supplemental Services Business.
BT Network Business
That part of BT's Systems Business that supplies network services to BT Retail Systems Business (at transfer charges) or to operators with Relevant Connectable System status (at Condition 13 charges).
C. (CCITT signallng system number 7) signalling interface
Operators with Relevant Connectable System status are entitled to interconnect with BT's system at so-called "points of connection" in order that calls may be passed to and from such systems for delivery to customers connected to either system or other interconnected systems. The "C. signalling interface", in the context of this document, allows the transfer of messages across these points of connection and so enables the setting up, routing and clearing of calls across network boundaries. It provides access to a wider range of services within BT's network than available to customers connected at the edge of the network at a network termination point. The interface is based on standards set by the CCITT (the former name of the world telecommunications standards-making body).
Call diversion
A network service that allows a customer to have the network redirect incoming calls to another number.
Call Minder
A call answering service provided by BT. Incoming messages can be left if the customer's line is busy or not answering.
Call return
A network service based on the use of calling line identity which allows a customer to return the last call received.
Call waiting
A network service whereby a customer engaged on a call is given an indication that another caller is attempting to reach the customer's number.
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.
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.
Charge Card
BT's calling card service.
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 under the Telecommunications Act 1984 to all persons or to persons of a class, as distinct from an individual licence which is granted to a particular person.
Condition 13 charges
The cost-based charges, set in accordance with Condition 13 of BT's licence, at which BT Network Business must supply network services to operators with Relevant Connectable System status and to BT Retail Systems Business.
Controlled routing service
A proposed service that would enable independent service providers to indicate to a network operator the number to which a call should be delivered, without the physical call path needing to extend, for the duration of the call, beyond the network boundary to the service provider's own equipment.
Cross-subsidy
The use of profits derived from the sale of one good or service to finance losses made by another.
Double 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 to another tandem exchange (ie one that does have direct connections to end users) and finally on to the end user.
End-to-end network services
See the description in paragraph 1.10(b). Those network services provided to customers other than network operators as part of a basic retail service.
End user
See the description in paragraph 1.7. The final customer for a service, not itself in the business of selling services to third parties.
Enhanced services
See the description in paragraph 1.12. All services with a telecommunications component but containing some function over and above basic retail services. They are made up of basic retail services plus additional elements that add value and are generally capable of being supplied by independent service providers.
Featurenet
BT's virtual private network 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 X25 service.
Independent service provider
See the description in paragraph 1.6. Those service providers who are not network operators or owned by network operators.
Individual licence
A licence granted under the Telecommunications Act 1984 to a particular person, as distinct from a class licence which is granted to all persons or to persons of a class.
Integrated Services Digital Network (ISDN)
A wideband network based on the PSTN providing end-to-end digital connectivity to support a wider range of services than is possible over a narrowband network.
Interconnection
The connection of separate telecommunication networks.
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 apparatus.
International Simple Resale (ISR)
The collection of traffic from the PSTN in the UK, switching it onto a leased line to another country across the international gateway operated by BT or Mercury, and then breaking back out onto the public network in the other country.
International facilities licence
A licence granted under the Telecommunications Act 1984 authorising the connection of a UK telecommunication system to a telecommunication system outside the UK and the provision of telecommunication services over the system to countries outside the UK. At present only BT and Mercury have been granted such licences. Other operators may lease international facilities from BT or Mercury in order to provide International Simple Resale.
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.
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 falback 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.
Market power
The ability to set prices without being constrained by the actions of competitors or potential competitors.
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.
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.
Network services
See the description in paragraph 1.9. Services which can realistically be provided economically only by a network operator. The basic transmission and switching services required for the provision of any basic retail service or enhanced service.
Network interconnection services
See the description at paragraph 1.10(a). The term refers to network services that are sold to other network operators.
Network operator
See the description in paragraph 1.5. The operator of a telecommunication network with a Public Telecommunications Operator (PTO) licence, which provides, amongst other things, network services.
Network charge control
Also known as "network price cap". A new tariff control for BT operating on the charges raised by BT from other network operators for network interconnection services provided by BT Network Business. Oftel has proposed that the new control should be structured on the lines of the proposed retail price control. That is, a series of controls related to the degree of competition in the markets for the services in question. Controls would apply both to charges for individual services and charges for a group (or "basket") of services. Oftel's detailed proposals were set out in the consultative document "Pricing of telecommunications services from 1997" published in December 1995.
Network Termination Point (NTP)
The edge of the network at which the network is connected to other networks or to terminal apparatus.
Number translation
A facility whereby calls made to 'special' numbers such as free phone (0800, 0500), part-paid (0345, 0645), premium rate (0891 etc), national rate (0990) and personal numbers are directed to their 'real' numbers following translation of the special number concerned.
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.
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.
Premium rate service
A service provided by telephone, charged at a higher rate than a normal call because the price includes both the cost of conveying the call and a charge levied by the provider of the service accessed.
Prioritised circuit bumping
Displacement of lower priority information being carried by a circuit with information of a higher priority.
Private circuit
A telecommunication link provided by a network operator for the exclusive use of the customer.
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.
Public switched telecommunication network (PSTN)
The telecommunication networks of the major PTOs. PTOs are required to interconnect with each other on request in order to enable calls between all customers of all PSTNs.
Public telecommunications operator (PTO)
Network operators with powers granted by the Secretary of State under the Telecommunications Act to enable them to install their systems on public and private land, property etc.
Relevant Connectable System (RCS)
Defined in BT's licence. In essence, and with certain exceptions, it means a telecommunication system run under an individual licence, authorised for connection to BT's system, and providing services which have been or are to be conveyed over BT's network, for reward to the public. BT is required to provide network services to operators with RCS status at Condition 13 charges (ie essentially "cost plus"). The main categories of licensee with RCS status are PTOs, international simple resale operators and personal numbering operators.
Reseller
An operator that does not own a network but leases lines from a network operator usually in order to provide basic retail services to third parties.
Retail price control
The system of controls placed by Oftel on certain of BT's retail prices. The objective of the controls has been to mimic the effect of competition by exerting downward pressure on BT's retail prices thus encouraging increased efficiency to make good the reduction in revenues resulting from the price control. The basic control operates on the average change in the prices of a basket of retail services covering most of BT's principle services. This control is supported by controls on individual services usually limiting any increases to the rate of inflation. There are currently separate baskets and individual controls for telephone and private circuit services. The present controls include requiring BT to lower its retail prices for the services in the telephony basket by RPI minus 7.5% each year. It runs to July 1997. Oftel started public consultation on the next controls with the publication in December 1995 of "Pricing of telecommunications services from 1997". For the first time, Oftel proposes to combine the retail price control with a network charge control.
Service provider
See the description in paragraph 1.6. In this Document, any person (whether part of a network operator or not) providing a service with a telecommunication service component to third parties.
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.
Structural separation
The placing of different activities in separate companies not controlled by the same parent company. This is usually achieved through divestment of a business or subsidiary.
Supplemental Services Business (SSB)
Defined in BT's licence by reference to the 1987 Value Added and Data Services Class Licence. In essence it means that part of BT's business that provides all telecommunication services or enhanced services except "voice telephony and telex messages" (which are in BT's Systems Business).
Switched multi-megabit data service (SMDS)
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).
System business (SB)
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 voice and telex messages, as distinct from the Supplemental Services Business.
Telecommunication service
Defined in the Telecommunications Act as a service consisting in the conveyance by means of a telecommunication system of speech, music and other sounds, visual images and certain other signals.
Telemetry
A service providing the ability to collect remote information (from an electricity meter for example).
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.
Transfer charge
A nominal charge for accounting purposes at which one part of an integrated company charges another part of that company for services provided to it.
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 will be carried over the network, or supplies the consumer equipment needed to access services it provides.
Virtual private network
A service for the interconnection of Private Branch Exchanges (PBXs) and/or Centrex lines, using the transmission and switching capabilities of the PSTN, as an alternative to a private circuit.
Voicemail
A voice messaging service.
X.25 service
A widely available, low speed, packet switched data service (see packet service), operating at speeds below those offered by Frame Relay.