METHODS AND SYSTEMS FOR SELECTION OF CHANNELS FOR UNLICENSED WIRELESS COMMUNICATIONS

• US 20170094675A1
• Filed: 09/29/2015
• Published: 03/30/2017
• Est. Priority Date: 09/29/2015
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Salem, Mohamed Adel, Maaref, Amine
• Granted Patent: US 9,974,089 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

Methods, devices and systems are disclosed to enable the use of unlicensed wireless channels by nodes and devices in a network, such as a mobile or cellular communications network, which primarily operates over licensed wireless channels. A selected channel, or selected channel and node pair for serving a user device are determined based on a combined metric of a signal quality level and a target time share parameter. The time share parameter represents the estimated data rate available for each potential channel, or channel and node pair, in light of the requirement to share the unlicensed wireless channel resources with other equipment. The signal quality level represents an estimated signal quality at the user device for each channel and node based on factors including residual interference from other communications signals transmitted over the unlicensed channels.

Claims

1. A method for selection of an unlicensed wireless channel, comprising:

for a user device and one or more network nodes;

determining a signal quality level associated with each of the one or more network nodes and each of two or more unlicensed wireless channels available to the user device and to that network node; and

obtaining a target time share parameter associated with each of the two or more unlicensed wireless channels and each of the one or more network nodes; and

selecting an unlicensed wireless channel for use as a carrier by the user device, the unlicensed wireless channel being selected based on both the signal quality level and the target time share parameter.

2. The method of claim 1, further comprising jointly selecting the unlicensed wireless channel and a network node for serving the user device, the unlicensed wireless channel and the network node being jointly selected based on both the signal quality level and the target time share parameter.

3. A method according to claim 1 wherein the signal quality level is determined based on an estimated residual interference at the user device over the unlicensed wireless channel.

4. A method according to claim 1 further comprising:

obtaining a first report of signals detected by the user device for the two or more unlicensed wireless channels available to the user device and any of the one or more network nodes;

obtaining received power measurements from the user device for at least one licensed wireless channel over which the user device operates; and

wherein for the one or more network nodes, determining the signal quality level associated with the two or more unlicensed wireless channels comprises;

obtaining a second report of signals detected by the network node for the two or more unlicensed wireless channels available to the user device and to that network node;

determining a residual interference at the user device for the two or more unlicensed wireless channels based on the first and second reports of signals; and

determining the signal quality level associated with that network node and the two or more unlicensed wireless channels based on a ratio of the received power measurement to the residual interference at the user device.

5. A method according to claim 4,

wherein obtaining the first report of signals detected by the user device comprises obtaining a first report of a signal power and an equipment identifier for each signal detected by the user device over the two or more unlicensed wireless channels at or above a carrier sensing threshold, wherein equipment associated with the equipment identifiers detected by the user device comprise a first group of equipment;

wherein obtaining the second report of signals detected by the network node comprises obtaining a second report of a signal power and an equipment identifier for each signal detected by the network node over the two or more unlicensed wireless channels at or above a carrier sensing threshold, wherein equipment associated with the equipment identifiers detected by the network node comprise a second group of equipment; and

wherein determining the residual interference at the user device for each of the two or more unlicensed wireless channels based on the first and second reports of signals comprises determining an interference level from residual equipment in the first group of the equipment which are not present in the second group of the equipment.

6. A method according to claim 5 wherein the equipment comprises any combination of wireless local area network (WLAN) access points or WLAN capable transmitters, and wherein the associated equipment identifiers comprise service set identifiers (SSID).

7. A method according to claim 5 wherein two or more network nodes are associated in a radio access cluster (RAC) for scheduling communications over a particular unlicensed wireless channel, wherein equipment associated with the equipment identifiers detected by each network node in the RAC comprise a third group of equipment, and wherein determining the residual interference at the user device for that network node and the particular unlicensed wireless channel comprises determining the interference level from the residual equipment in the first group of equipment which is not present in the third group of equipment.

8. A method according to claim 7 further comprising determining an additional interference level from one or more RACs configured to use the two or more unlicensed wireless channels and wherein determining the signal quality level associated with the network node and each of the two or more unlicensed wireless channels available to the user device and to that network node comprises determining the ratio of the received power measurement to a sum of the residual interference level and the additional interference level at the user device.

9. A method according to claim 8 wherein the additional interference level is determined based on uplink sounding signals sent by the user device over the at least one licensed channel and adjusted to account for differences in frequency between the licensed wireless channel and the two or more unlicensed wireless channels.

10. A method according to claim 8 wherein the additional interference level is determined based on uplink sounding signals sent by the user device over the two or more unlicensed wireless channels.

11. A method according to claim 5 wherein the received power measurements from the user device comprise reference signal received power (RSRP) measurements obtained over a licensed wireless channel or an unlicensed wireless channel and adjusted to account for differences in frequency between the wireless channel over which the RSRP measurement is received and the two or more unlicensed wireless channels.

12. A method according to claim 2 further comprising:

for the one or more network nodes;

determining a bandwidth share parameter associated with the network node and the two or more unlicensed wireless channels available to the user device and to that network node; and

wherein the selected unlicensed wireless channel and the selected network node are selected based on a combination of the signal quality level, the target time share parameter and the bandwidth share parameter.

13. A method according to claim 1 wherein the one or more network nodes comprises one network node serving the user device on a primary component carrier operating over a licensed wireless channel, and wherein the one network node serves the user device on a secondary component carrier operating over the selected unlicensed wireless channel.

14. A method according to claim 2 wherein the selected network node serves the user device on a secondary component carrier operating over the selected unlicensed wireless channel, and wherein a different network node serves the user device on a primary component carrier operating over a licensed wireless channel.

15. A method according to claim 1 wherein the unlicensed wireless channels are channels for a wireless local area (WLAN) network or a WiFi™

network.

16. A controller comprising:

a communications interface;

a processor; and

one or more non-transitory computer readable media having computer readable instructions stored thereon for transmitting and receiving data through the communications interface, the instructions, when executed by the processor, direct the controller to;

for a user device and one or more network nodes in a wireless communications network;

determine a signal quality level associated with each of the one or more network nodes and each of two or more unlicensed wireless channels available to that network node and to the user device; and

obtain a target time share parameter associated with each of the two or more unlicensed wireless channels and each of the one or more network nodes; and

select an unlicensed wireless channel for use as a carrier by the user device, the unlicensed wireless channel being selected based on both the signal quality level and the target time share parameter.

17. A controller according to claim 16 wherein the instructions, when executed by the processor, further direct the controller to jointly select the unlicensed wireless channel and a network node for serving the user device, the unlicensed wireless channel and the network node being jointly selected based on both the signal quality level and the target time share parameter.

18. A controller according to claim 16 wherein the signal quality level is determined based on an estimated residual interference at the user device over the unlicensed wireless channel.

19. A controller according to claim 16 wherein the instructions, when executed by the processor, further direct the controller to:

obtain a first report of signals detected by the user device for the two or more unlicensed wireless channels available to the user device and any of the one or more network nodes;

obtain received power measurements from the user device for at least one licensed wireless channel over which the user device operates; and

wherein for the one or more network nodes, the controller is directed to determine the signal quality level associated with the two or more unlicensed wireless channels by,

obtaining a second report of signals detected by the network node for the two or more unlicensed wireless channels available to the user device and to that network node;

determining a residual interference at the user device for the two or more unlicensed wireless channels based on the first and second reports of signals; and

determining the signal quality level associated with that network node and two or more unlicensed wireless channels based on a ratio of the received power measurement to the residual interference at the user device.

20. A controller according to claim 19,

wherein the first report of signals detected by the user device comprises a first report of a signal power and an equipment identifier for each signal detected by the user device over the two or more unlicensed wireless channels at or above a carrier sensing threshold, wherein equipment associated with the equipment identifiers detected by the user device comprise a first group of equipment;

wherein the second report of signals detected by the network node comprises a second report of a signal power and an equipment identifier for each signal detected by the network node over the two or more unlicensed wireless channels at or above a carrier sensing threshold, wherein equipment associated with the equipment identifiers detected by the network node comprise a second group of equipment; and

wherein determining the residual interference at the user device for each the two or more unlicensed wireless channels based on the first and second reports of signals comprises determining an interference level from residual equipment in the first group of the equipment which are not present in the second group of the equipment.

21. A controller according to claim 17 wherein the instructions, when executed by the processor, further direct the controller to re-determine the selected unlicensed wireless channel for use as the carrier by the user device and the selected network node for serving the user device in response to a handover of the user device from a first primary cell to a second primary cell, in response to a request to offload traffic for the user device to an unlicensed wireless channel, or in response to a periodic trigger.

22. A controller according to claim 20 wherein the instructions, when executed by the processor, further direct the controller to:

associate two or more network nodes in a radio access cluster (RAC) for scheduling communications over a particular unlicensed wireless channel;

wherein equipment associated with the equipment identifiers detected by each network node in the RAC comprise a third group of equipment; and

wherein determining the residual interference at the user device for the particular unlicensed wireless channel comprises determining the interference level from the residual equipment in the first group of equipment which is not present in the third group of equipment.

23. A controller according to claim 22 wherein the instructions, when executed by the processor, further direct the controller to:

determine an additional interference from one or more RACs configured to use the two or more unlicensed wireless channels, and determine the signal quality indicator associated with the network node and each of the two or more unlicensed wireless channels available to the user device and to that network node based on the ratio of the received power measurement to a sum of the residual interference level and the additional interference at the user device.

24. A controller according to claim 23 wherein the instructions, when executed by the processor, further direct the controller to determine the additional interference level based on uplink sounding signals sent by the user device over the at least one licensed channel and adjusted to account for differences in frequency between the licensed wireless channel and the two or more unlicensed wireless channels.

25. A controller according to claim 17 wherein the instructions, when executed by the processor, further direct the controller to:

determine the signal quality level associated with the one or more network nodes and the two or more unlicensed wireless channels available to that network node and to each one of a plurality of user devices; and

select an unlicensed wireless channel for use as a carrier by each of the plurality of user devices, and a network node for serving each of the plurality of user devices, the selected unlicensed wireless channel and the selected network node being selected jointly based on both the signal quality level and the target time share parameter;

wherein the selected unlicensed wireless channel and the selected network node for each of the plurality of user devices is determined periodically and sequentially in a randomly interleaved manner.

26. A controller according to claim 17 wherein the instructions, when executed by the processor, further direct the controller to:

for the one or more network nodes;

determine a bandwidth share parameter associated with the network node and the two or more unlicensed wireless channels available to the user device and to that network node; and

wherein the selected unlicensed wireless channel and the selected network node are selected based on a combination of the signal quality level, the target time share parameter and the bandwidth share parameter.