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.