. This context may typically contain location information (e.g. current cell(s) of the UE) and information about allocated radio resources and related connection references UTRAN SYNCHRONIZATION AND O&M REQUIREMENTS 3.6.1 Synchronization Model The main synchronization issues in UTRAN include: network, node, transport channel, radio interface, and time alignment synchronization. Figure 3.10 illustrates the nodes involved in these issues (with exception of network and node synchronization). Vocoder Time Alignment Handling Transport Channel Synchronization Node B Node B Node B Node B Node B Radio Interface UTRAN Synchronization [TDD] Radio Interface Sync. Optional TDD only inpu & output sync ports Figure 3.10 Synchronization issues model. The UMTS Development Platform 3.6.2 Node B O&M Figure 3.11 illustrates the two Node B O&M types, i.e. the implementation specific O&M linked to the actual implementation of Node B, and the logical O&M having im- pacts on the traffic carrying resources in Node B controlled from the RNC. 3.6.2.1 Implementation Specific O&M Implementation specific O&M functions depend on both HW and SW management components of Node B, and their transport from Node B to the management system occurs via the RNC. The implementation specific O&M interface shares the same physical bearer with the lub interface, where [8] specifies the routing function and the transport bearer. Routing across the RNC in the UTRAN is optional, but signalling between co-located equipment and its management system is required, this may be carried over the same bearer as the implementation specific O&M. 3.6.2.2 Logical O&M The logical O&M represents the signalling associated with the control of logical re- sources owned by the RNC but physically implemented in Node B (e.g. channels, cells, etc.). The RNC controls these logical resources. A number of O&M procedures physi- cally implemented in Node B impact on the logical resources requiring an information exchange between RNC and Node B. All messages needed to support this infor