Accommodating Semi-Persistent Scheduling in Heterogeneous Networks with Restricted Subframe Patterns

• US 20130114573A1
• Filed: 07/10/2012
• Published: 05/09/2013
• Est. Priority Date: 11/04/2011
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Research In Motion Limited (Blackberry Limited)
• Inventors: Suzuki, Takashi, Cai, Zhijun
• Granted Patent: US 8,976,764 B2
• Time in Patent Office: Days
• US Class Current: 370/336
• CPC Class Codes: H04L 1/0086 Unequal error protection H04L27/00 and H04L1/004 take precedence for layer 1/2 aspects, e.g. bit loading
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04W 16/32 Hierarchical cell structures

Abstract

A method is provided for operating a network element in a wireless communications network. The method comprises transmitting, by a network element configured to utilize time domain measurement resource restriction, a first initial transmission under an SPS scheme, wherein retransmissions of the first initial transmission follow a first retransmission pattern. The method further comprises transmitting, by the network element, a second initial transmission under the SPS scheme, wherein retransmissions of the second initial transmission follow a second retransmission pattern, the second retransmission pattern allowing at least one retransmission of the second initial transmission to occur in a restricted subframe.

Claims

1. A method for operating a network element in a wireless communications network, the method comprising:

transmitting, by a network element configured to utilize time domain measurement resource restriction, a first initial transmission under a semi-persistent scheduling (SPS) scheme, wherein retransmissions of the first initial transmission follow a first retransmission pattern that is aligned with a restricted subframe pattern; and

transmitting, by the network element, a second initial transmission under the SPS scheme, wherein retransmissions of the second initial transmission follow a second retransmission pattern, the second retransmission pattern allowing at least one retransmission of the second initial transmission to occur in a restricted subframe.

2. The method of claim 1, further comprising adjusting, by a scheduler in the network element, the second retransmission pattern to align the at least one retransmission of the second initial transmission to the restricted subframe.

3. The method of claim 1, wherein restricted subframes occur in a 1/8 pattern, wherein initial transmissions occur every 20 subframes, wherein retransmissions in the first retransmission pattern occur every 8 subframes and coincide with restricted subframes, and wherein the at least one retransmission of the second initial transmission occurs twelve subframes later than the second initial transmission.

4. The method of claim 1, wherein restricted subframes occur in a 1/8 pattern, wherein a first set of initial transmissions and a second set of initial transmissions each occur every 40 subframes with a 24 subframe offset between the first set of initial transmissions and the second set of initial transmissions, and wherein retransmissions occur every 8 subframes and coincide with restricted subframes.

5. The method of claim 4, wherein the number of retransmissions of the second initial transmission is limited to one.

6. The method of claim 1, wherein restricted subframes do not occur in a 1/8 pattern, and wherein initial transmissions and retransmissions align with restricted subframes.

7. The method of claim 6, wherein initial transmissions occur every 20 subframes, wherein retransmissions occur 8 subframes after an initial retransmission or a previous retransmission, and wherein restricted subframes are aligned with initial transmissions or retransmissions.

8. The method of claim 1, further comprising activating, reactivating, or releasing SPS in a restricted subframe, by the network element.

9. The method of claim 1, further comprising using, by the network element, a more robust modulation and coding scheme for data packets that have fewer opportunities for retransmission in a restricted subframe than the network element uses for data packets that have more opportunities for retransmission in a restricted subframe.

10. The method of claim 1, further comprising using, by the network element, a synchronous non-adaptive downlink hybrid automatic repeat request (HARQ) scheme when a physical downlink control channel (PDCCH) is not used for retransmission.

11. The method of claim 1, wherein the network element is a victim node in a heterogeneous network.

12. The method of claim 11, wherein the victim node is at least one of:

a pico cell;

a femto cell;

a macro cell;

or

a relay.

13. A network element in a wireless communications network, the network element comprising:

a processor configured such that the network element, configured to utilize time domain measurement resource restriction, transmits a first initial transmission under a semi-persistent scheduling (SPS) scheme,

wherein retransmissions of the first initial transmission follow a first retransmission pattern that is aligned with a restricted subframe pattern,

wherein the processor is further configured such that the network element transmits a second initial transmission under the SPS scheme,

wherein retransmissions of the second initial transmission follow a second retransmission pattern,

wherein the second retransmission pattern allows at least one retransmission of the second initial transmission to occur in a restricted subframe.

14. The network element of claim 13, wherein a scheduler in the network element adjusts the second retransmission pattern to align the at least one retransmission of the second initial transmission to the restricted subframe.

15. The network element of claim 13, wherein restricted subframes occur in a 1/8 pattern, wherein initial transmissions occur every 20 subframes, wherein retransmissions in the first retransmission pattern occur every 8 subframes and coincide with restricted subframes, and wherein the at least one retransmission of the second initial transmission occurs twelve subframes later than the second initial transmission.

16. The network element of claim 13, wherein restricted subframes occur in a 1/8 pattern, wherein a first set of initial transmissions and a second set of initial transmissions each occur every 40 subframes with a 24 subframe offset between the first set of initial transmissions and the second set of initial transmissions, and wherein retransmissions occur every 8 subframes and coincide with restricted subframes.

17. The network element of claim 16, wherein the number of retransmissions of the second initial transmission is limited to one.

18. The network element of claim 13, wherein restricted subframes do not occur in a 1/8 pattern, and wherein initial transmissions and retransmissions align with restricted subframes.

19. The network element of claim 18, wherein initial transmissions occur every 20 subframes, wherein retransmissions occur 8 subframes after an initial retransmission or a previous retransmission, and wherein restricted subframes are aligned with initial transmissions or retransmissions.

20. The network element of claim 13, wherein the network element activates, reactivates, or releases SPS in a restricted subframe.

21. The network element of claim 13, wherein the network element uses a more robust modulation and coding scheme for data packets that have fewer opportunities for retransmission in a restricted subframe than the network element uses for data packets that have more opportunities for retransmission in a restricted subframe.

22. The network element of claim 13, wherein the network element uses a synchronous non-adaptive downlink hybrid automatic repeat request (HARQ) scheme when a physical downlink control channel (PDCCH) is not used for retransmission.

23. The network element of claim 13, wherein the network element is a victim node in a heterogeneous network.

24. The network element of claim 23, wherein the victim node is at least one of:

a pico cell;

a femto cell;

a macro cell;

or

a relay.

25. A method for operating a network element in a wireless communications network, the method comprising:

transmitting, by the network element, configured to utilize time domain measurement resource restriction, a first initial transmission under a semi-persistent scheduling (SPS) scheme; and

transmitting, by the network element, a second initial transmission under the SPS scheme,

wherein first initial transmissions and second initial transmissions occur every 40 subframes,

wherein a retransmission of the first initial transmission occurs at least once 8 subframes after the first initial transmission, and a retransmission of the second initial transmission occurs at least once 8 subframes after the second initial transmission, and

wherein the retransmissions of the first initial transmission and the second initial transmission are aligned with a restricted subframe pattern.

26. A network element in a wireless communications network, the network element comprising:

a processor configured such that the network element, configured to utilize time domain measurement resource restriction, transmits a first initial transmission under a semi-persistent scheduling (SPS) scheme,

wherein the processor is further configured such that the network element transmits a second initial transmission under the SPS scheme,

wherein first initial transmissions and second initial transmissions occur every 40 subframes,

wherein a retransmission of the first initial transmission occurs at least once 8 subframes after the first initial transmission, and a retransmission of the second initial transmission occurs at least once 8 subframes after the second initial transmission, and

wherein the retransmissions of the first initial transmission and the second initial transmission are aligned with a restricted subframe pattern.

27. A method for operating a network element in a wireless communications network, the method comprising:

transmitting, by the network element, configured to utilize time domain measurement resource restriction, an initial transmission under a semi-persistent scheduling (SPS) scheme,

wherein initial transmissions occur every 20 subframes,

wherein a retransmission of an initial transmission occurs at least once 10 subframes after the initial transmission, and

wherein the retransmissions of the initial transmission are aligned with restricted subframes.

28. The method of claim 27, wherein the number of retransmissions is limited to one.

29. A network element in a wireless communications network, the network element comprising:

a processor configured such that the network element, configured to utilize time domain measurement resource restriction, transmits an initial transmission under a semi-persistent scheduling (SPS) scheme,

wherein initial transmissions occur every 20 subframes,

wherein a retransmission of an initial transmission occurs at least once 10 subframes after the initial transmission, and

wherein the retransmissions of the initial transmission are aligned with restricted subframes.

30. The network element of claim 29, wherein the number of retransmissions is limited to one.

31. A method for operating a user equipment (UE) in a wireless communications network, the method comprising:

receiving, by the UE, a first initial transmission under a semi-persistent scheduling (SPS) scheme, wherein retransmissions of the first initial transmission follow a first retransmission pattern; and

receiving, by the UE, a second initial transmission under the SPS scheme, wherein retransmissions of the second initial transmission follow a second retransmission pattern, the second retransmission pattern allowing at least one retransmission of the second initial transmission to occur in a restricted subframe.

32. A user equipment (UE) comprising:

a processor configured such that the UE receives a first initial transmission under a semi-persistent scheduling (SPS) scheme,

wherein retransmissions of the first initial transmission follow a first retransmission pattern,

wherein the processor is further configured such that the UE receives a second initial transmission under the SPS scheme,

wherein retransmissions of the second initial transmission follow a second retransmission pattern, and

wherein the second retransmission pattern allows at least one retransmission of the second initial transmission to occur in a restricted subframe.

33. A method for operating an underlay network element in a wireless heterogeneous network including an overlay network element, the method comprising:

receiving, by the underlay network element, a pattern signifying subframes in which a transmission power of the overlay network element will be reduced;

transmitting, by the underlay network element, a first packet comprising a value; and

transmitting, by the underlay network element, a second packet comprising the value in one of the signified subframes.

34. The method of claim 33, further comprising:

receiving, by the underlay network element, an indication that the first packet was received in error; and

scheduling, by the underlay network element, transmission of the second packet in a subsequent signified subframe.