Siemens EWSD

With more than 200 million ports installed in over one hundred countries worldwide, the EWSD was most recently marketed under the Nokia Siemens Networks brand and many of its parts are now discontinued.

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.

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.