Section: 10.3.1 Skip indicator
Content: Bits 5 to 8 of the first octet of every Mobility Management message and GPRS MobilityManagement message contains the skip indicator. With the exception of the following cases for a shared GERAN network in A/Gb mode, - when the MS is sending a LOCATION UPDATING REQUEST, CM SERVICE REQUEST, IMSI DETACH INDICATION or CM RE-ESTABLISHMENT REQUEST message; or - when the network is receiving a LOCATION UPDATING REQUEST, PAGING RESPONSE, CM SERVICE REQUEST, IMSI DETACH INDICATION or CM RE-ESTABLISHMENT REQUEST message, the skip indicator field shall be handled as follows: a) A message received with skip indicator different from 0000 shall be ignored. A message received with skip indicator encoded as 0000 shall not be considered an error that causes the message to be ignored. b) A protocol entity sending a Mobility Management message or a GPRS Mobility Management message shall encode the skip indicator as 0000. In a shared GERAN network in A/Gb mode: a) When the MS is sending a LOCATION UPDATING REQUEST, CM SERVICE REQUEST, IMSI DETACH INDICATION or CM RE-ESTABLISHMENT REQUEST message, - if the MS is a GERAN network sharing supporting MS, the MS shall encode the skip indicator IE to indicate the chosen PLMN identity from the PLMN identities in the broadcast system information (see 3GPP TS 44.018[ None ]  [84]) according to table 10.3.1; - otherwise, the MS shall encode the skip indicator as 0000. b) When the network is receiving a LOCATION UPDATING REQUEST, PAGING RESPONSE, CM SERVICE REQUEST, IMSI DETACH INDICATION or CM RE-ESTABLISHMENT REQUEST message, - if the skip indicator is encoded as 0000, the message shall not be considered an error that causes the message to be ignored; - if the skip indicator is different from 0000, the message shall not be considered an error and shall be processed by the receiving MM entity. The MS shall be considered as GERAN network sharing supporting MS. NOTE: The skip indicator handling of PAGING RESPONSE message on the MS and the BSS is specified in 3GPP TS 44.018[ None ]  [84]. Figure 10.3.1: Skip indicator Table 10.3.1/3GPP TS 24.008[ Mobile radio interface Layer 3 specification; Core network protocols; Stage 3 ] : Skip indicator