Power saving satellite connection for low capability device

1 . A low capability device (UE) active in a communication system comprising a plurality of satellites (Si,Sj) insuring a temporally continuous communication coverage for the low capability device (UE), said satellites (Si,Sj) being further grouped in families, satellites of a same family sharing same and common access information,

said device (UE), having performed a first communication session with a serving satellite (S11) of one family (S1x) for a data session, is such that it comprises a power saving module to send to the serving satellite (S11), during the first data session, a next access request for a next or continued data session with time indications including at least a desired next time interval to be granted for communication,

said power saving module being also adapted to receive, from the serving satellite (S11), and to process assigned timing information for a next connection to a satellite (S12) of the same family, said assigned timing information being determined such that it indicates to the device (UE) idle mode synchronization information in order for a paging to occur at the occurrence of the assigned time information, corresponding to the desired time interval requested by the device (UE), with a designated next satellite (S12) of the same family (S1x),

said power saving module being such that it then adapts the idle mode according to the idle mode synchronization information in order for the device (UE) to receive information from the next satellite (S12) of the same family and to connect to the next satellite (S12) of the same family, reusing same and common access information as read for the previously serving satellite (S11).

2 . The low capability device according to claim 1 , wherein assigned timing information for resuming or continuing communication being related to the presence duration of a next satellite (S12) of the same satellite family (S1x), it indicates idle mode synchronization information in order for a paging to occur, in the desired time interval requested by the device (UE), using idle mode adaptation in the device (UE), in early phase of reachability of the next available satellite (S12) of the same family (S1x) and in order for said next data session to be performed and terminated prior reachability of the next satellite (S12) being of the same satellite family (S1x) terminates.

3 . The low capability device according to claim 2 , wherein assigned timing information indicates to the device idle mode synchronization information in order for a paging to occur, in the desired time interval requested by the device (UE), using idle mode adaptation in the device (UE), no later than the end of the first quarter of presence of a next available satellite (S12) of the same family (S1x) and in order for the next data session to be performed before the beginning of the last quarter of presence of this next available satellite (S12).

4 . A method to manage data sessions in a low capability device (UE) active in a communication system comprising a plurality of satellites (Si,Sj) insuring a temporally continuous communication coverage for the low capability device (UE), said satellites (Si,Sj) being further grouped in families (S1x), satellites of a same family (S1x) sharing same and common access information,

said method comprising a preliminary step of performing a first communication session with a serving satellite (S11) of one family (S1x) for a data session, during which the same and common access information are read,

said method then comprising the following steps to save power for next or continued data session:

sending, to the serving satellite (S11), during the first data session, a next access request for a next or continued data session with time indications including at least a desired next time interval to be granted for communication,

receiving, from the serving satellite (S11), and processing assigned timing information for a next connection to a satellite of the same family (S1x), said assigned timing information being determined such that it indicates to the device (UE) idle mode synchronization information in order for a paging to occur at the occurrence of the assigned time information, corresponding to the desired time interval requested by the device (UE), with a designated next satellite (S12) of the same family (S1x),

adapting the idle mode according to the idle mode synchronization information in order for the device (UE) to receive information from the next satellite (S12) of the same family (S1x) and to connect to the designated next satellite (S12) of the same family (S1x), reusing common access information as read for the previously serving satellite (S11).

5 . The method according to claim 4 , wherein assigned timing information for resuming or continuing communication being related to the presence duration of the next satellite (S12) of the same satellite family (S1x), it indicates idle mode synchronization information in order for a paging to occur, in the desired time interval requested by the device (UE), using idle mode adaptation in the device (UE), in early phase of reachability of the next available satellite (S12) of the same family (S1x) and in order for said next data session to be performed and terminated prior reachability of the next satellite (S12) being of the same satellite family (S1x) terminates.

6 . A method according to claim 5 , wherein assigned timing information indicates to the device (UE) idle mode synchronization information in order for a paging to occur, in the desired time interval requested by the device (UE), using idle mode adaptation in the device (UE), no later than the end of a first period of presence of a next available satellite (S12) of the same family (S1x) and in order for the next data session to be performed before the beginning of a last period of presence of this next available satellite (S12), wherein the first and the last period of presence is evaluated in such a way that a corresponding communication session is finalized prior disappearance of said next satellite (S12).

7 . A method according to claim 6 , wherein first period and last period of the presence of a next satellite correspond to any one of the following fractions: a quarter of the satellite presence, a third of the satellite presence.