Section: 8.109 Presence Reporting Area Information
Content: Presence Reporting Area Information is coded as depicted in Figure 8.109-1. Figure 8.109-1: Presence Reporting Area Information The PRA Identifier in octets 5 to 7 shall be present and shall contain the identifier of the PRA the UE is entering or leaving. It shall be encoded using full hexadecimal representation (binary, not ASCII encoding). The PRA Identifier is defined in clause 19.10 of 3GPP TS 23.003[ Numbering, addressing and identification ]  [2]. The PRA Identifier in the Octets 5 to 7 shall be set to the PRA Set ID if the MME/SGSN is requested to report the change of UE presence in a PRA Set. In this case: - the Additional PRA (APRA) flag in octet 8 shall be set to 1 if the reporting of change of UE presence for the PRA Set is active and the UE presence has changed for at least one PRA within the PRA Set (i.e. if the UE enters or leaves the PRA Set, or the UE moves between the PRAs within the PRA Set). The subsequent 4 octets shall then be present and shall contain the identifier of the individual PRA within the PRA Set which the UE has newly entered or left, with the information of whether the UE is inside or outside this PRA. - the Additional PRA (APRA) flag in octet a+3 shall be set to 1 if the UE presence status has changed for more than one individual PRA within the PRA Set. In that case, the subsequent 4 Octets shall be included and encoded as specified above for the octets a to a+3. The MME/SGSN shall report each individual PRA(s) within the PRA Set that the UE has newly entered or left. - if the reporting of change of UE presence for the PRA Set is inactive, i.e. the INAPRA flag in octet 8 is set to 1, then the Additional PRA (APRA) flag in octet 8 shall not be set to 1 and no Additional PRA Identifier shall be included. The Inside PRA flag (IPRA) shall be set to 1 if the UE is inside or enters the Presence Reporting Area identified by the PRA Identifier. The Outside PRA flag (OPRA) shall be set to 1 if the UE is outside or leaves the Presence Reporting Area identified by the PRA Identifier. The Inactive PRA (INAPRA) flag in octet 8 shall be set to 1 if the PRA is inactive in the MME/SGSN, i.e. the reporting of change of UE presence in this PRA is currently deactivated in the MME/SGSN, e.g. due to an overload situation. Either the IPRA or the OPRA flag or the INAPRA shall be set to 1, not several ones, for a given Presence Reporting Area Identifier.