Circuit emulation service

Circuit Emulation Service (CES) is an emerging telecommunication technology used to transmit time-division multiplexed Asynchronous Transfer Mode services over packet switched networks.

The core networks are in the evolution to packet switched networks such as Metro Ethernet, IP/Ethernet and MPLS. These packet switching based networks provide more cost-effective communications with comparison with traditional TDM based networks (PDH, SDH), especially for today's exponentially increasing Internet services.

But the legacy TDM and ATM equipment has been widely deployed in traditional telecommunication networks: PBX in enterprise offices, PDH/SDH equipment in carrier offices and near wireless stations. These investments are providing a big portion of service providers' profits and must be protected in the future. Especially the widely deployed 2G and 2.5G base stations are using TDM based interfaces to communicate with BSC (Base Station Controller). The early deployed 3G Node B is using ATM based protocols running on PDH/SDH physical interfaces. These base stations will exist for quite a long time in evolution to LTE.

Circuit Emulation Service technology provides future-ready solution to seamlessly migrate to packet switched networks. With CES, the legacy TDM and ATM services are supported with much more cost-effective infrastructures based on low-cost and highly available Ethernet devices. This a reverse mapping approach with regard to traditional solutions in which IP/Ethernet services is carried in ATM or PDH/SDH protocols.

CES technology makes it possible to leverage the modern network technologies like MPLS or IP backbones, Metro Ethernet, WiFi, IP-DSLAM and GPON/EPON access networks.

CES providers

• Zarlink Semiconductor, ZL501XX series of chips with SAToP and CESoPSN support
• RAD Commmunication, CES gateway equipment for office and wireless applications
• Cambridge Industries Group, low-cost port-intensive CES access equipment integrated with GPON/EPON access technology

CES had been used for the technology of TDM over ATM, before it is referred as TDM/ATM over PSN.

See also

ATM Forum#Circuit Emulation Service