4 Xw signalling bearer
36.4623GPPEvolved Universal Terrestrial Radio Access Network (E-UTRAN) and Wireless LAN (WLAN)Release 17TSXw signalling transport
4.1 Function and protocol stack
Xw signalling bearer provides the following functions:
– Provision of reliable transfer of Xw-AP message over Xw interface.
– Provision of networking and routeing function;
– Provision of redundancy in the signalling network;
– Support for flow control and congestion control.
The protocol stack for Xw Signalling Bearer is shown in figure 4.1-1 and details on each protocol are described in the following sections.
Figure 4.1-1: Xw signalling bearer protocol stack
The Transport Network Layer is based on IP transport, comprising SCTP on top of IP.