System Y
Encyclopedia
System Y is a digital telephone exchange
system used by British Telecom
, the operator of the United Kingdom's telephone network.
British Telecom decided to use the AXE10 digital switch in the mid-1980s to end its total reliance on GEC's System X
. This also kept GEC from using a position of dominance to charge BT unfair amounts for provision of System X equipment parts. Although System X is more abundant in BT's network, AXE10 is still widespread in Britain.
AXE10 covers two main types of digital telephony
switching equipment - the RSS (Remote Subscriber Switch) and the AXE10 local switch. RSS acts as a remote concentrator
and deals with the conversion of analogue telephony signals used in the access network
(the copper pairs between exchange buildings and customers' premises, also called 'local loop
') and the multiplexing of customer lines over cabling to the AXE10 local switching unit. The AXE10 local switch uses a processor-controlled switch to route calls and data depending on the destination of the telephony transmission.
BT's AXE10 network, which has been in service since 1986, is maintained in house by its own engineers although Ericsson
still provide high-level support, software upgrades and repairs at component level.
Both System Y and System X are likely to be phased out as BT implements its 21st Century Network
based on VoIP
and replacing existing switches, ADSL and analogue equipment with fully digital Multiple Service Access Nodes (MSAN
).
Electronic switching system
In telecommunications, an electronic switching system is:* A telephone exchange based on the principles of time-division multiplexing of digitized analog signals. An electronic switching system digitizes analog signals from subscriber loops, and interconnects them by assigning the digitized...
system used by British Telecom
BT Group
BT Group plc is a global telecommunications services company headquartered in London, United Kingdom. It is one of the largest telecommunications services companies in the world and has operations in more than 170 countries. Through its BT Global Services division it is a major supplier of...
, the operator of the United Kingdom's telephone network.
British Telecom decided to use the AXE10 digital switch in the mid-1980s to end its total reliance on GEC's System X
System X (telephony)
System X was the name of the UK's first national digital telephone exchange system.-Development:System X was developed by the UK Post Office , GEC, Plessey, and Standard Telephones and Cables and first shown in public in 1979 at the Telecom 79 exhibition in Geneva Switzerland...
. This also kept GEC from using a position of dominance to charge BT unfair amounts for provision of System X equipment parts. Although System X is more abundant in BT's network, AXE10 is still widespread in Britain.
AXE10 covers two main types of digital telephony
Digital telephony
Digital telephony is the use of digital electronics in the provision of digital telephone services and systems. Since the 1960s a digital core network has almost entirely replaced the old analog system, and much of the access network has also been digitized...
switching equipment - the RSS (Remote Subscriber Switch) and the AXE10 local switch. RSS acts as a remote concentrator
Remote concentrator
In modern telephony a remote concentrator, Remote Concentrator Unit , or Remote Line Concentrator is the lowest level in the telephone switch hierarchy.Subscribers' analogue telephone/PSTN lines are terminated on concentrators...
and deals with the conversion of analogue telephony signals used in the access network
Access network
An access network is that part of a telecommunications network which connects subscribers to their immediate service provider. It is contrasted with the core network, which connects local providers to each other...
(the copper pairs between exchange buildings and customers' premises, also called 'local loop
Local loop
In telephony, the local loop is the physical link or circuit that connects from the demarcation point of the customer premises to the edge of the carrier or telecommunications service provider's network...
') and the multiplexing of customer lines over cabling to the AXE10 local switching unit. The AXE10 local switch uses a processor-controlled switch to route calls and data depending on the destination of the telephony transmission.
BT's AXE10 network, which has been in service since 1986, is maintained in house by its own engineers although Ericsson
Ericsson
Ericsson , one of Sweden's largest companies, is a provider of telecommunication and data communication systems, and related services, covering a range of technologies, including especially mobile networks...
still provide high-level support, software upgrades and repairs at component level.
Both System Y and System X are likely to be phased out as BT implements its 21st Century Network
BT 21CN
The 21st Century Network programme is the network transformation project of the UK telecommunications company BT Group plc for data and voice. It had been intended to move BT's telephone network from the present AXE/System X Public Switched Telephone Network to an Internet Protocol system...
based on VoIP
Voice over IP
Voice over Internet Protocol is a family of technologies, methodologies, communication protocols, and transmission techniques for the delivery of voice communications and multimedia sessions over Internet Protocol networks, such as the Internet...
and replacing existing switches, ADSL and analogue equipment with fully digital Multiple Service Access Nodes (MSAN
MSAN
A Multi-service access Node also known as a Multi-service access gateway is a device typically installed in a telephone exchange which connects customers' telephone lines to the core network, to provide telephone, ISDN, and broadband such as DSL all from a single platform.Prior to the deployment...
).