3 Definitions of terms, symbols and abbreviations

37.4723GPPRelease 16TSW1 signalling transport

3.1 Terms

For the purposes of the present document, the terms and definitions given in 3GPP TR 21.905 [1] and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in 3GPP TR 21.905 [1].

ng-eNB: as defined in 3GPP TS 38.300 [6]

SCTP association: as defined in IETF RFC 4960 (2007-09) [5]

SCTP endpoint: as defined in IETF RFC 4960 (2007-09) [5]

W1: interface between a ng-eNB-CU and a ng-eNB-DU, providing an interconnection point between the ng-eNB-CU and the ng-eNB-DU.

W1-C: Reference point for the control plane protocol between ng-eNB-CU and ng-eNB-DU.

3.2 Symbols

Void.

3.3 Abbreviations

For the purposes of the present document, the abbreviations given in 3GPP TR 21.905 [1] and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in 3GPP TR 21.905 [1].

DiffServ Differentiated Service

IANA Internet Assigned Number Authority

IP Internet Protocol

PPP Point to Point Protocol

SCTP Stream Control Transmission Protocol

4. W1-C signalling bearer

4.1 Function and protocol stack

The W1-C signalling bearer provides the following functions:

– Provision of reliable transfer of W1AP messages over the W1-C 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 W1-C Signalling Bearer is shown in figure 4.1-1 and details on each protocol are described in the following clauses.

Figure 4.1-1: W1-C signalling bearer protocol stack

The Transport Network Layer is based on IP transport, comprising SCTP on top of IP.