Apparatus, method and computer program product providing idle mode discontinuous reception
View Patent ↗A network sends an indication of discontinuous reception period (ldle_Mode_DRX_Period) and an indication of number of paging groups (Paging_Group_Count). Paging occasions for a user equipment are determined by a predetermined formula. One exemplary formula is SFN mod IDLE_Mode_DRX_Period=(IDLE_Mode_DRX_Period div Paging_Group_Count) *(ID) mod (Paging_Group_Count); where SFN is system frame number and ID is the identifier of the user equipment, which can be IMSI or some value derived from IMSI. The UE's temporary ID is sent during a determined paging occasion, which maps to a paging channel on which the page is sent. Options for restricting the paging occasion to less than a frame, and for offsetting the paging occasions from that of the above formula are detailed.
1. A method comprising:
receiving an indication of a discontinuous reception period and an indication of a number of paging groups;
determining paging occasions for a user equipment by applying the indicated discontinuous reception period, the indicated number of paging groups and an identifier of the user equipment to a predetermined formula; and
monitoring a control channel during the determined paging occasions,
wherein the predetermined formula comprises:
SFN mod IDLE_Mode — DRX _Period=(IDLE_Mode — DRX _Period div Paging_Group_Count)*(ID)mod(Paging_Group_Count);
wherein SFN is system frame number,
Idle_Mode_DRX_Period is the discontinuous reception period,
Paging_Group_Count is the number of paging groups, and
ID is the identifier of the user equipment which comprises an international mobile subscriber identity of the user equipment or a value derived from the international mobile subscriber identity.
2. The method of claim 1 , wherein the indication of the discontinuous reception period is a three bit indication i such that 2 i =Idle_Mode_DRX_Period; and the indication of the number of paging groups is a three bit indication n such that 2 n =Paging_Group_Count.
3. The method of claim 1 , further comprising receiving an indication of a paging occasion offset for shifting paging occasions, and wherein the determined paging occasions are shifted by the indicated paging occasion offset.
4. The method of claim 3 , wherein the predetermined formula comprises:
(
SFN
-
DRX_offset
_parameter
)
mod
(
Idle_Mode
_DRX
_Period
)
=
(
Idle_Mode
_DRX
_Period
Paging_Group
_Count
)
*
(
ID
)
mod
(
Paging_Group
_Count
)
wherein SFN is system frame number,
DRX_offset parameter is the paging occasion offset,
Idle_Mode_DRX_Period is the discontinuous reception period,
Paging_Group_Count is the number of number of paging groups, and
ID is the identifier of the user equipment which comprises an international mobile subscriber identity of the user equipment or a value derived from the international mobile subscriber identity.
5. The method of claim 1 , further comprising:
receiving an indication of a paging indication subframe count; and
restricting the paging occasions to span less than a frame based at least in part on the paging indication subframe count.
6. The method of claim 5 , further comprising:
receiving an indication of an offset of the paging occasion subframe count; and
offsetting, from an end of the frame, the paging occasions that are restricted to span less than the frame, based at least in part on the offset of the paging occasion subframe count.
7. The method of claim 1 , wherein monitoring the control channel during the determined paging occasions further comprises monitoring a physical downlink control channel for a temporary identifier assigned to the user equipment, and
wherein the method further comprising, for the case where the temporary identifier is received on the monitored control channel during one of the paging occasions, receiving, at the user equipment, a page on a paging channel that is identified by the temporary identifier on the physical downlink control channel.
8. An apparatus comprising at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following:
to receive an indication of a discontinuous reception period and an indication of a number of paging groups;
to determine paging occasions for the apparatus by applying the discontinuous reception period, the number of paging groups and an identifier of the apparatus to a predetermined formula; and
to monitor a control channel during the determined paging occasions,
wherein the predetermined formula comprises:
SFN mod IDLE_Mode — DRX _Period=(IDLE_Mode — DRX _Period div Paging_Group_Count)*(ID)mod(Paging_Group_Count);
wherein SFN is system frame number,
Idle_Mode_DRX_Period is the discontinuous reception period,
Paging_Group_Count is the number of paging groups, and
ID is the identifier of the apparatus which comprises an international mobile subscriber identity of the apparatus or a value derived from the international mobile subscriber identity.
9. The apparatus of claim 8 , wherein the indication of the discontinuous reception period is a three bit indication i such that 2 i =Idle_Mode_DRX_Period; and the indication of the number of paging groups is a three bit indication n such that 2 n =Paging_Group_Count.
10. The apparatus of claim 8 , wherein the at least one memory and the computer program code are further configured to cause the apparatus to receive an indication of a paging occasion offset for shifting all paging occasions, and wherein the processor is configured to determine paging occasions by shifting according to the indicated paging occasion offset.
11. The apparatus of claim 10 , wherein the predetermined formula comprises:
(
SFN
-
DRX_offset
_parameter
)
mod
(
Idle_Mode
_DRX
_Period
)
=
(
Idle_Mode
_DRX
_Period
Paging_Group
_Count
)
*
(
ID
)
mod
(
Paging_Group
_Count
)
wherein SFN is system frame number,
DRX_offset parameter is the paging occasion offset,
Idle_Mode_DRX_Period is the discontinuous reception period,
Paging_Group_Count is the number of number of paging groups, and
ID is the identifier of the apparatus which comprises an international mobile subscriber identity of the apparatus or a value derived from the international mobile subscriber identity.
12. The apparatus of claim 8 , wherein the receiver is further configured the at least one memory and the computer program code are further configured to cause the apparatus to receive an indication of a paging indication subframe count, and the processor is configured to use the paging indication subframe count so as to restrict the paging occasions to span less than a frame.
13. The apparatus of claim 12 , wherein the at least one memory and the computer program code are further configured to cause the apparatus to receive an indication of an offset of the paging occasion subframe count, and the processor is configured to use the offset of the paging occasion subframe count to offset from an end of the frame the paging occasions that are restricted to span less than the frame.
14. The apparatus of claim 8 , wherein, when monitoring the control channel during the determined paging occasions, the at least one memory and the computer program code are further configured to cause the apparatus to monitor a physical downlink control channel for a temporary identifier assigned to the apparatus, and
wherein, for the case where the receiver receives the temporary identifier on the monitored control channel during one of the paging occasions, the at least one memory and the computer program code are further configured to cause the apparatus to receive a page on a paging channel that is identified by the temporary identifier on the physical downlink control channel.
15. A non-transitory computer readable memory embodying a computer program that is executable by a digital processor to perform actions directed to monitoring for a page, the actions comprising:
in response to receiving indications of a discontinuous reception period and of a number of paging groups, determining paging occasions for a user equipment by applying the indicated discontinuous reception period, the indicated number of paging groups and an identifier of the user equipment to a predetermined formula; and
monitoring a control channel during the determined paging occasions,
wherein the predetermined formula comprises:
SFN mod IDLE_Mode — DRX _Period=(IDLE_Mode — DRX _Period div Paging_Group_Count)*(ID)mod(Paging_Group_Count);
wherein SFN is system frame number,
Idle_Mode_DRX_Period is the discontinuous reception period,
Paging_Group_Count is the number of paging groups, and
ID is the identifier of the user equipment which comprises an international mobile subscriber identity of the apparatus or a value derived from the international mobile subscriber identity.
16. The non-transitory computer readable memory of claim 15 , wherein monitoring the control channel during the determined paging occasions further comprises monitoring a physical downlink control channel for a temporary identifier assigned to the user equipment, and
wherein the actions further comprise, for the case where the temporary identifier is received on the monitored control channel during one of the paging occasions, receiving a page on a paging channel that is identified by the temporary identifier on the physical downlink control channel.
17. An apparatus comprising at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following:
to transmit an indication of a discontinuous reception period and an indication of a number of paging groups;
to assign a temporary identifier to a user equipment and to determine at least one paging occasion for the user equipment by applying the indicated discontinuous reception period, the indicated number of paging groups and another identifier of the user equipment to a predetermined formula;
wherein the predetermined formula comprises:
SFN mod IDLE_Mode — DRX _Period=(IDLE_Mode — DRX _Period div Paging_Group_Count)*(ID)mod(Paging_Group_Count);
wherein SFN is system frame number,
Idle_Mode_DRX_Period is the discontinuous reception period,
Paging_Group_Count is the number of paging groups, and
ID is the another identifier of the user equipment which comprises an international mobile subscriber identity of the user equipment or a value derived from the international mobile subscriber identity.
18. The apparatus of claim 17 , where the apparatus is further configured to send to the user equipment the assigned temporary identifier on a physical downlink control channel during the determined at least one paging occasion; and
to send, to the user equipment, a page on a paging channel that is identified by the temporary identifier on the physical downlink control channel.