ULTRA LOW LATENCY DESIGN FOR LTE

• US 20150280871A1
• Filed: 03/03/2015
• Published: 10/01/2015
• Est. Priority Date: 03/28/2014
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Xu, Hao, Malladi, Durga Prasad, Bhushan, Naga, Ji, Tingfang, Gaal, Peter, Chen, Wanshi, Luo, Tao, Wei, Yongbin, Damnjanovic, Aleksandar
• Granted Patent: US 10,420,054 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01Q 5/25 Ultra-wideband [UWB] systems, e.g. multiple resonance systems; Pulse systems
• CPC Class Codes: H04B 7/2043 Mixed mode, TDM and FDM systems
• CPC Class Codes: H04J 1/16 Monitoring arrangements for transmission in general H04B17/00; for amplifiers H03F1/52, H03F1/523
• CPC Class Codes: H04J 3/14 Monitoring arrangements for SDH/SONET rings H04J3/085
• CPC Class Codes: H04J 3/1694 Allocation of channels in TDM/TDMA networks, e.g. distributed multiplexers Passive Optical Networks H04Q11/0062
• CPC Class Codes: H04L 1/0018 based on latency requirement
• CPC Class Codes: H04L 47/283 in response to processing delays, e.g. caused by jitter or round trip time [RTT]
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0035 Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0064 Rate requirement of the data, e.g. scalable bandwidth, data priority
• CPC Class Codes: H04L 5/0092 Indication of how the channel is divided
• CPC Class Codes: H04L 5/06 the signals being represented by different frequencies combined with time-division multiplexing H04L5/26
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04W 28/0236 radio quality, e.g. interference, losses or delay
• CPC Class Codes: H04W 56/0065 using measurement of signal travel time
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 74/0866 using a dedicated channel for access

Abstract

Methods, systems, and devices are described for low latency communications within a wireless communications system. An eNB and/or a UE may be configured to operate within the wireless communications system and may send triggers to initiate communications using a dedicated resource in a wireless communications network that supports transmissions having a first subframe type and a second subframe type, the first subframe type comprising symbols of a first duration and the second subframe type comprising symbols of a second duration that is shorter than the first duration. Communications may be initiated by transmitting a trigger from the UE or eNB using the dedicated resource, and initiating communications following the trigger. The duration of time between the trigger and initiating communications can be significantly shorter than the time to initiate communications using legacy LTE communications.

Claims

1. A method for wireless communications, comprising:

establishing communications in a wireless communications network that supports transmissions having a first subframe type and a second subframe type, the first subframe type comprising symbols of a first duration and the second subframe type comprising symbols of a second duration that is shorter than the first duration; and

monitoring a predetermined wireless communications resource for a trigger to initiate transmissions having the second subframe type.

2. The method of claim 1, further comprising:

determining that the trigger is received; and

receiving transmissions having the second subframe type,

wherein a latency between the determining and receiving is less than a latency between initiating transmissions having the first subframe type and receiving transmissions having the first subframe type.

3. The method of claim 1, wherein the monitoring comprises monitoring a dedicated frequency resource for the trigger, and wherein the dedicated frequency resource comprises a dedicated frequency division multiplexing (FDM) subband continuously available for the monitoring.

4. The method of claim 1, wherein the monitoring comprises monitoring a dedicated frequency resource for the trigger, and wherein a bandwidth of the dedicated frequency resource is based on a number of devices configured to transmit or receive the trigger using the dedicated frequency resource.

5. The method of claim 1, wherein the monitoring comprises monitoring a dedicated frequency resource for the trigger, and wherein the dedicated frequency resource comprises two or more discontiguous resource blocks of a FDM resource.

6. The method of claim 1, wherein the monitoring comprises:

monitoring a dedicated time resource for the trigger wherein the dedicated time resource comprises a predefined portion of a time division multiplexing (TDM) subframe, the predefined portion comprising one or more symbols of the TDM subframe having the first duration, wherein the one or more symbols of the TDM subframe comprise a first symbol of the TDM subframe and a second symbol of the TDM subframe, and wherein at least one subsequent symbol of the TDM subframe following the one or more symbols has the second duration.

7. The method of claim 1, wherein the monitoring is performed by a user equipment (UE), and wherein the method further comprises:

determining that the trigger is received;

determining transmission resources that are to be used for receiving one or more subframes having the second subframe type at the UE.

8. The method of claim 7, wherein the determining that the trigger is received comprises one or more of:

determining that the trigger is received on a predefined resource associated with the UE;

or

determining that the trigger includes an identification that identifies the UE.

9. The method of claim 1, wherein the monitoring is performed by a base station, and wherein the method further comprises:

determining that the trigger is received from a user equipment (UE);

transmitting an assignment of resources to the UE for transmitting one or more subframes having the second subframe type.

10. The method of claim 9, wherein the trigger comprises one or more of:

a UE identification;

a delay requirement;

or

a bandwidth requirement.

11. The method of claim 9, wherein the determining that the trigger is received from the UE comprises:

determining that two or more triggers are received from two or more UEs; and

resolving contention between the two or more UEs,

wherein the transmitting the assignment comprises transmitting the assignment of resources to one of the two or more UEs responsive to the resolving contention between the two or more UEs.

12. The method of claim 1, wherein the monitoring is performed by a base station, and wherein the method further comprises:

determining that the trigger is received from a user equipment (UE); and

receiving an autonomous transmission from the UE comprising subframes having the second subframe type.

13. A method for wireless communications, comprising:

establishing communications in a wireless communications network that supports transmissions having a first subframe type and a second subframe type, the first subframe type comprising symbols of a first duration and the second subframe type comprising symbols of a second duration that is shorter than the first duration;

determining that data is to be transmitted using one or more subframes having the second subframe type; and

transmitting a trigger using a predetermined wireless communications resource to initiate transmissions having the second subframe type.

14. The method of claim 13, wherein the method is performed by a base station, and wherein the method further comprises:

transmitting the one or more subframes having the second subframe type following the trigger.

15. A method for wireless communications, comprising:

configuring a first latency mode and a second latency mode in a wireless communications network, wherein transmissions in the first latency mode have a first round trip time (RTT) between transmission and acknowledgment of receipt of the transmission, and transmissions in the second latency mode have a second RTT that is less than the first RTT; and

configuring a resource for devices operating in the wireless communications network to trigger use of the second latency mode.

16. The method of claim 15, wherein the resource comprises one of a dedicated time resource or a frequency resource.

17. The method of claim 16, wherein the frequency resource comprises a dedicated frequency division multiplexing (FDM) subband continuously available for monitoring.

18. The method of claim 16, wherein the second latency mode is configured to operate on a dedicated component carrier.

19. The method of claim 18, wherein the dedicated component carrier is configured as a secondary cell (SCell) component carrier.

20. The method of claim 19, wherein resources on the SCell component carrier are assigned by a base station using a primary cell (PCell) component carrier, and wherein a plurality of resources in the SCell component carrier are assigned using a single resource of the PCell component carrier.

21. The method of claim 19, wherein resources on the SCell component carrier are assigned by a base station using a single scheduling resource within the SCell component carrier.

22. The method of claim 19, wherein an acknowledgment of receipt of transmissions for a plurality of resources in the SCell component carrier is provided by a single resource of the PCell component carrier.

23. The method of claim 15, wherein configuring the first latency mode and the second latency mode comprises:

configuring a first subset of resources within a component carrier for first latency mode communications, and configuring a second subset of resources within the component carrier for second latency mode communications.

24. The method of claim 23, wherein the first subset of resources and second subset of resources are dynamically configured based on an amount of data to be transmitted using the second latency mode.

25. The method of claim 15, wherein configuring the first latency mode and the second latency mode comprises:

configuring a first component carrier to operate using the first latency mode; and

configuring a second component carrier to operate using the second latency mode.

26. The method of claim 25, wherein the resource comprises a dedicated frequency division multiplexing (FDM) subband within the second component carrier continuously available for monitoring.

27. The method of claim 15, wherein the resource is dynamically or semi-statically configured.

28. The method of claim 27, wherein the resource is a predefined group of resource blocks transmitted using the first latency mode.

29. The method of claim 15, wherein the resource is one or more symbols in a time division multiplexing subframe transmitted using the first latency mode.

30. An apparatus for wireless communications, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory, the instructions being executable by the processor to;

configure a first latency mode and a second latency mode in a wireless communications network, wherein transmissions in the first latency mode have a first round trip time (RTT) between transmission and acknowledgment of receipt of the transmission, and transmissions in the second latency mode have a second RTT that is less than the first RTT; and

configure a resource for devices operating in the wireless communications network to trigger use of the second latency mode.