8.2.206 MBS Session Identifier
29.2443GPPInterface between the Control Plane and the User Plane nodesRelease 17TS
The MBS Session Identifier is used to identify a 5G MBS Session. It contains the Temporary Mobile Group Identity as defined in 3GPP TS 23.003 [2] or a Source Specific IP multicast address which consists of two IP addresses, one is an IP unicast address used as source address in IP packets for identifying the source of the multicast service (e.g. AF/AS), the other is an IP multicast address used as destination address in related IP packets for identifying a multicast service associated with the source.
It is coded as specified in Figure 8.2.206-1.
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Bits |
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Octets |
8 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
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1 to 2 |
Type = 305 (decimal) |
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3 to 4 |
Length = n |
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5 |
Spare |
NIDI |
SSMI |
TMGI |
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6-11 |
TMGI |
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12-m |
Source Specific IP Multicast Address |
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|
o to (o+5) |
NID |
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q-(n+4) |
These octet(s) is/are present only if explicitly specified |
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Figure 8.2.206-1: MBS Session Identifier
The following bits within Octet 5 shall indicate:
– Bit 1 – TMGI: if this bit is set to "1", it indicates that the TMGI field shall be present, otherwise it shall not be present;
– Bit 2 – SSMI: if this bit is set to "1", it indicates that the Source Specific IP Multicast Address field shall be present, otherwise it shall not be present;
– Bit 3 – NIDI: if this bit is set to "1", it indicates that the Network Identifier (NID) field shall be present, otherwise it shall not be present;
– Bit 4 to 8 – Spare, for future use, shall be set to "0" by the sender and discarded by the receiver.
The TMGI field shall be encoded as octets 3 to octet 8 in the figure 10.5.154 of 3GPP TS 24.008 [5].
The Source Specific IP Multicast Address field shall be encoded the octets 10 to m of IE Multicast Transport Information as specified in 8.2.207.
The NID field shall be encoded with 11 hexadecimal digit, bit 8 to bit 5 of the octet "o" is the most significant digit and bit 8 to bit 5 of the octet "o+5" is the least significant digit, and bits 4 to 1 of octets (o+5) shall all be encoded as 0.