7.7.94 User CSG Information (UCI)

29.0603GPPGeneral Packet Radio Service (GPRS)GPRS Tunnelling Protocol (GTP) across the Gn and Gp interfaceRelease 17TS

User CSG Information (UCI) is coded as depicted in Figure 7.7.94.1. The CSG ID is defined in 3GPP TS 23.003 [2].

Bits
Octets	8	7	6	5	4	3	2	1
1	Type = 194 (Decimal)
2-3	Length
4	MCC digit 2				MCC digit 1
5	MNC digit 3				MCC digit 3
6	MNC digit 2				MNC digit 1
7	spare					CSG ID
8-10	CSG ID
11	Access mode		Spare					CMI

Figure 7.7.94.1: User CSG Information

For two digits MNCs, bits 5 to 8 of octet 5 are coded as "1111".

The CSG ID consists of 4 octets. Bit 3 of Octet 7 is the most significant bit and bit 1 of Octet 10 is the least significant bit. The coding of the CSG ID is the responsibility of the operator that allocates the CSG ID by administrative means. Coding using full hexadecimal representation (binary, not ASCII encoding) shall be used.

Access mode values are specified in Table 7.7.94.1.

Table 7.7.94.1: Access mode values and their meanings

Access Mode	Values (Decimal)
Closed Mode	0
Hybrid Mode	1
Reserved	2-3

CSG Membership Indication (CMI) values are specified in Table 7.7.94.2. CMI shall be included in the User CSG Information if the Access mode is Hybrid Mode. For the other values of Access Mode, the CMI shall be set to 0 by the sender and ignored by the receiver.

Table 7.7.94.2: CSG Membership Indication (CMI)

CMI	Values (Decimal)
CSG membership	0
Non CSG membership	1

NOTE: Due to a specification oversight, the CMI values in the above table are reversed from the values of the CSG-Membership-Indication AVP in 3GPP TS 32.299 [56]. Therefore, when CMI values are sent over the charging interface, the values are encoded as specified in 3GPP TS 32.299 [56]. Furthermore, the encoding is different between GTPv1 and GTPv2.