Section: 9.9.3.36 UE security capability
Content: The UE security capability information element is used by the network to indicate which security algorithms are supported by the UE in S1 mode, Iu mode and Gb mode. Security algorithms supported in S1 mode are supported both for NAS and for AS security. If the UE supports S101 mode, then these security algorithms are also supported for NAS security in S101 mode. The UE security capability information element is coded as shown in figure 9.9.3.36.1 and table 9.9.3.36.1. The UE security capability is a type 4 information element with a minimum length of 4 octets and a maximum length of 7 octets. Octets 5, 6, and 7 are optional. If octet 5 is included, then also octet 6 shall be included and octet 7 may be included. If a UE did not indicate support of any security algorithm for Gb mode, octet 7 shall not be included. If the UE did not indicate support of any security algorithm for Iu mode and Gb mode, octets 5, 6, and 7 shall not be included. If the UE did not indicate support of any security algorithm for Iu mode but indicated support of a security algorithm for Gb mode, octets 5, 6, and 7 shall be included. In this case octets 5 and 6 are filled with the value of zeroes. Figure 9.9.3.36.1: UE security capability information element Table 9.9.3.36.1: UE security capability information element