School of Specs 24.501v20.0.0

3GPP 24.501 v20.0.0 — the document's own text

5.5.3 eCall inactivity procedure

Taught in 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).

The eCall inactivity procedure is performed only in 3GPP access and applicable only to a UE configured for eCall only mode as specified in 3GPP TS 31.102 [22]. The procedure shall be started when:

  • the UE is in any 5GMM-REGISTERED substate except substates 5GMM-REGISTERED.PLMN-SEARCH or 5GMM-REGISTERED.NO-CELL-AVAILABLE;
  • the UE is in 5GMM-IDLE mode or 5GMM-CONNECTED mode with RRC inactive indication; and
  • one of the following conditions applies:
    • timer T3444 expires or is found to have already expired and timer T3445 is not running;
    • timer T3445 expires or is found to have already expired and timer T3444 is not running; or
    • timers T3444 and T3445 expire or are found to have already expired.

The UE shall then perform the following actions:

  • all NAS timers are stopped and associated procedures aborted except for timers T3245, the timer TF, the timer TG, (see 3GPP TS 23.122 [5]), the timer instance associated with the entry in the list of "PLMNs not allowed to operate at the present UE location" and the timer instance associated with the entry in the list of "LSP PLMNs not allowed to operate at the present UE location", the UE shall reset the registration attempt counter and service request attempt counter;
  • if the UE is currently registered to the network for 5GS services, perform a de-registration procedure;
  • delete any 5G-GUTI, TAI list, last visited registered TAI, list of equivalent PLMNs, and ngKSI;

c1) if the UE is operating in single-registration mode, the UE shall handle EMM parameters, EMM state, EPS update status, 4G-GUTI, last visited registered TAI, TAI list, eKSI, attach attempt counter, tracking area updating attempt counter and service request attempt counter as specified in 3GPP TS 24.301 [15] for the eCall inactivity procedure; and

  • enter 5GMM-DEREGISTERED.eCALL-INACTIVE state.

If the UE is configured for eCall only mode as specified in 3GPP TS 31.102 [23] and moves from GERAN or UTRAN to NG-RAN, the UE shall:

  • if timer T3242 is running, start timer T3444 with the time left on T3242 and stop timer T3242;
  • if timer T3243 is running, start timer T3445 with the time left on T3243 and stop timer T3243; and
  • if timer T3242 or timer T3243 is running, perform an initial registration procedure for 5GS services.

NOTE: Timers T3242 and T3243 are specified in 3GPP TS 24.008 [12].