The Siemens EWSD periphery is comprised of the following:
- Remote Switching Unit (RSU) – Connects subscribers and trunks; can replace local exchanges
- Line Trunk Group (LTG) – Connects subscribers and trunks. These are some different types of LTG’s:
- LTG(M): GSMYAA, GSMYDC, GPLSx, DIU120, PMUx, GPLC, etc.
- LTG(N): GPNYx, GPNLx, etc.
- LTG(P): GPPYx, GPSx, etc.
Digital Line Unit (DLU) – Connects subscribers and concentrates the traffic to the LTG. These are some different types of DLU’s:
- DLU(A): SLMA:COS, SLMA:CMRL.
- DLU(B): SLMA:FPE, DLUS30, ALEX, SLMD:QFB.
- DLU(G): SLMA:ITM, SLMA:ITF, SLMD:QFB, SLMI:xxx, etc.
The DLU can be re-used as an integral part of the Siemens NGN SURPASS access solution:
- Synchronous Transport Module Interface (STMI) – Provides a fully integrated STM-1 interface to the SDH network. It can be used to interconnect switches as well as to connect RSUs or RDLUs to the switch.
- Host Timeslot Interchange (HTI) – For connection of the RSU.
The Siemens EWSD core is comprised of the:
- Switching Network (SN) – Creates the connections between subscribers.
- Coordination Processor (CP) – Performs call processing and routing. As a multiprocessor, the CP can be extended to meet all performance requirements. When operating at maximum capacity, the CP113 can handle up to 16 million Busy Hour Call Attempts (BHCA).
- Signaling System Network Control (SSNC) – Controls the SS7 signaling Traffic supporting SS7 over TDM, SS7 over ATM and also SS7 over IP.
