7 Transport layer
36.4623GPPEvolved Universal Terrestrial Radio Access Network (E-UTRAN) and Wireless LAN (WLAN)Release 17TSXw signalling transport
SCTP (IETF RFC 4960 [5]) shall be supported as the transport layer of Xw signalling bearer. The Payload Protocol Identifier assigned by IANA to be used by SCTP for the application layer protocol XwAP is 59.
SCTP refers to the Stream Control Transmission Protocol developed by the Sigtran working group of the IETF for the purpose of transporting various signalling protocols over IP network.
There shall be only one SCTP association established between one eNB and WT pair.
The eNB shall establish the SCTP association. The SCTP Destination Port Number value assigned by IANA to be used for XwAP is 36462.
Within the SCTP association established between an eNB and WT pair;
– A single pair of stream identifiers shall be reserved for the sole use of XwAP elementary procedures that utilize non UE-associated signalling.
– At least one pair of stream identifiers shall be reserved for the sole use of XwAP elementary procedures that utilize UE-associated signalling. However a few pairs (i.e. more than one) should be reserved.
– A single UE-associated signalling shall use one SCTP stream and the stream should not be changed during the communication of the UE-associated signalling.
Transport network redundancy may be achieved by SCTP multi-homing between two endpoints, of which one or both is assigned with multiple IP addresses. SCTP endpoints shall support a multi-homed remote SCTP endpoint. For SCTP endpoint redundancy an INIT may be sent from WT or eNB, at any time for an already established SCTP association, which shall be handled as defined in IETF RFC 4960 [5] in sub-clause 5.2.
The SCTP congestion control may, using an implementation specific mechanism, initiate higher layer protocols to reduce the signalling traffic at the source and prioritise certain messages.
Annex A (informative):
Change history
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Change history |
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Date |
Meeting |
TDoc |
CR |
Rev |
Cat |
Subject/Comment |
New version |
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2015-10 |
RAN3#89bis |
R3-152078 |
Xw signaling support |
0.1.0 |
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2015-10 |
RAN3#89bis |
R3-152246 |
Xw_signaling support |
0.1.0 |
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2015-10 |
RAN3#89bis |
R3-152247 |
Draft_TS36462_Update |
0.1.0 |
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2015-11 |
RAN3#90 |
R3-152417 |
Draft_TS36462_Update |
0.2.0 |
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2015-11 |
RAN3#90 |
R3-152774 |
Draft_TS36462_Update |
0.3.0 |
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2015-11 |
RAN#70 |
RP-151865 |
Presentation Specification to TSG RAN#70 |
1.0.0 |
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2016-01 |
RAN3# Adhoc NB-IOT |
R3-160004 |
Editorial update: change “Xw signaling support” to “Xw signaling transport” |
1.1.0 |
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2016-01 |
RAN3# Adhoc NB-IOT |
R3-160123 |
Cover page update |
1.2.0 |
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2016-02 |
RAN3#91 |
R3-160155 |
Version update |
1.3.0 |
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2016-03 |
RAN#71 |
RP-160518 |
MCC clean up and version update |
2.0.0 |
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2016-03 |
RAN#71 |
Upgraded to Rel-13 and placed under change control |
13.0.0 |
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2017-03 |
SA#75 |
Promotion to Release 14 without technical change |
14.0.0 |
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2018-06 |
SA#80 |
– |
– |
– |
– |
Promotion to Release 15 without technical change |
15.0.0 |
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2020-07 |
SA#88-e |
– |
– |
– |
– |
Update to Rel-16 version (MCC) |
16.0.0 |
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2022-03 |
SA#95-e |
Promotion to Release 17 without technical change |
17.0.0 |
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