《WCDMA无线接入网简介(爱立信）》.pptVIP

* Synchronous optical networking (SONET) and Synchronous Digital Hierarchy (SDH), are two closely related multiplexing protocols for transferring multiple digital bit streams over the same optical fiber. The method was developed to replace the Plesiochronous Digital Hierarchy (PDH) system for transporting larger amounts of telephone calls and data traffic over the same fiber wire without synchronization problems. * 2006-01-25 * * 2006-01-25 * The UMTS CN EDGE translates the UMTS bearer service attributes into RAB service attributes. Also, the UMTS CN EDGE requests UTRAN to provide the required services. The UTRAN verifies with its admission/capability control whether the UTRAN supports the specific requested service and whether the required resources are available. In order to allow rational design of UMTS network, the overall end-to-end QoS requirements need to be broken down to specific sub-service requirements for the individual building blocks of the network - bearer services. each bearer service on a certain layer offers its specific services using services provided by lower layers The role of the Radio Bearer Service is to cover all the aspects of the radio interface transport. The Iu-Bearer Service together with the Physical Bearer Service provides the transport between UTRAN and CN. Iu bearer services for packet traffic shall provide different bearer services for a variety of QoS requirements. * 2006-01-25 * . From end-user and application point of view four major traffic classes can be identified for these bearers as illustrated in figure Conversational and streaming classes are intended to carry realtime traffic flows, like speech and video streaming. Interactive class and background class are mainly meant to be used by traditional Internet applications like WWW, e-mail and by a number of vertical applications like Telemetry and E-Commerce. Some operators have an idea to separate the voice data traffic into two different systems, i.e. GSM UMTS. Tha