ks in the echo canceller (EC). 8.10.2 PACKET WCDMA/UMTS CALLS In this example, the control signalling between the SGSN and RNC is routed via the media gateway. Assuming that the WCDMA/UMTS user equipment is attached, any packet call set-up is treated as PDP context. In the example the GGSN will not be physically split SO the server and the MGW part of it will co-reside. PDP Context Activation See Figure 4.41. PDP context: type of network, network address, access point name, QoS, radio priority, etc. 1. An Activate PDP context request is sent from the UE to the SGSN server. 2. A Create PDP context request is sent from the SGSN server to the GGSN via the connectivity layer (routers). 3. The GGSN server requests an IP address from the RADIUS server. 4. The GGSN server requests (internal communication) the GGSN MGW to create a GTP tunnel end point. 5. The GGSN server sends a Create PDP context response to the SGSN server. 6. The SGSN server requests WRAN to set-up a RAB. 7. Acknowledgement on RAB request from WRAN. Radius server server server 1,8,9 1,6,7,9 STM, ATM, IP TRANSPORT Internet Intranets User data Control Figure 8.41 Example of best-effort call set up in UMTS Service Implementation server server STM, ATM, IP TRANSPORT Internet Intranets User data Control Figure 8.42 Packet data transfer phase 8. The SGSN server requests the MGW to create a GTP tunnel transfer point. 9. Activate PDP context response is sent back to the UE from the SGSN. Packet Data Transfer, Uplink See Figure 8.42. 1. A packet data unit (PDU) is sent from the UE. 2. The PDU is sent over the GTP-U tunnel between the RNC and the MGW. 3. The PDU is sent over the GTP-U tunnel between the MGW and the GGSN MGW. The PDU is sent over to the Internet/Intranet. Service Network 'Overcoming the challenges of handling a multitude of services and business-related partners.' 9.1 OBJECTIVES The overall objective is to understand the increasing role, the architecture, way of working and the potential of the service network and all its 'domains'. Such techno-