Licensed-assisted access (LAA) in a C-RAN
Embodiments of a C-RAN are disclosed that support using Licensed-Assisted Access (LAA) deliver Long-Term Evolution (LTE) wireless service using unlicensed radio frequency (RF) spectrum.
1. A system to provide wireless service using one or more licensed radio frequency (RF) channels and one or more unlicensed RF channels, the system comprising:
a controller; and
a radio point;
wherein the radio point is associated with at least one antenna and remotely located from the controller, wherein the radio point is communicatively coupled to the controller;
wherein the controller and the radio point are configured to implement a base station in order to provide wireless service to a plurality of user equipment (UEs) on a primary cell using said one or more licensed RF channels;
wherein the controller is configured to schedule transmissions on said one or more licensed RF channels and said one or more unlicensed RF channels;
wherein the controller is communicatively coupled to a core network of a wireless service provider;
wherein the radio point is configured to transmit and receive RF signals to and from the UEs using said one or more licensed RF channels;
wherein the radio point is configured to transmit RF signals to at least some of the UEs using said one or more unlicensed RF channels and wherein the radio point is configured to use a listen-before-talk (LBT) channel access process to gain access to said one or more unlicensed RF channels; and
wherein the radio point is configured do the following in response to a request sent by the controller to the radio point to perform the LBT channel access process to attempt to gain access to said one or more unlicensed RF channels in order to transmit a burst starting at or before a first transmission time interval (TTI):
if the radio point is successful in gaining access to said one or more unlicensed RF channels in order to transmit the burst starting at or before the first TTI, transmit, on said one or more unlicensed RF channels, the burst starting at or before the first TTI; and
if the radio point is unsuccessful in gaining access to said one or more unlicensed RF channels in order to transmit the burst starting at or before the first TTI, not transmit, on said one or more unlicensed RF channels, the burst starting at or before the first TTI, re-process at least some data included in the burst for transmission starting at or before a later TTI, and transmit the burst with the re-processed data starting at or before the later TTI.
2. The system of claim 1 , wherein if the radio point is unsuccessful in gaining access to said one or more unlicensed RF channels in order to transmit the burst starting at or before the first TTI, sending a failure indication to the controller; and
wherein the controller, in response to receiving the failure indication, altering the scheduling of data to be transmitted during the burst to reflect a delay in gaining access to said one or more unlicensed RF channels.
3. The system of claim 1 , wherein Layer 1 processing for an air interface used for communicating using said one or more unlicensed RF channels is split between the controller and the radio point.
4. The system of claim 1 , wherein Long-Term Evolution (LTE) Licensed-Assisted Access (LAA) is used for communicating using said one or more unlicensed RF channels.
5. The system of claim 1 , further comprising a plurality of radio points;
wherein each of the radio points is associated with a respective at least one antenna and remotely located from the controller, wherein the plurality of radio points is communicatively coupled to the controller.
6. The system of claim 5 , wherein all of at least some of the radio points are configured to transmit and receive RF signals to and from the UEs using a same primary cell to transmit and receive RF signals using said one or more licensed RF channels; and
wherein each of said at least some of the radio points is configured to transmit RF signals using a respective different secondary cell using said one or more unlicensed RF channels.
7. The system of claim 5 , wherein the system comprises a plurality of controllers; and
wherein each individual controller included in the plurality of controllers is:
associated with a respective different set of radio points;
configured to use a respective primary cell associated with only said individual controller to provide wireless service using said one or more licensed RF channels; and
configured to use a respective different secondary cell for each radio point that is used by said individual controller to provide wireless service using said one or more unlicensed RF channels.
8. The system of claim 5 , wherein the system comprises a plurality of controllers; and
wherein the plurality of controllers is:
associated with a same set of radio points;
configured to all use a same primary cell to provide wireless service using said one or more licensed RF channels; and
configured to use a respective different secondary cell for each radio point that is used by the controllers to provide wireless service using said one or more unlicensed RF channels.
9. The system of claim 5 , wherein the system comprises a plurality of controllers;
wherein the controllers are configured to schedule transmissions on said one or more licensed RF channels and said one or more unlicensed RF channels; and
wherein the controllers are configured to coordinate scheduling of transmissions on said one or more unlicensed RF channels.
10. The system of claim 9 , wherein the controllers are configured to coordinate the use of the LBT channel access process among the radio points.
11. The system of claim 1 , wherein the controller is communicatively coupled to the radio point using a switched ETHERNET network.
12. The system of claim 1 , wherein the radio point comprises at least one of:
a radio point configured to use only said one or more licensed RF channels;
a radio point configured to use only said one or more unlicensed RF channels; and
a radio point configured to use both said one or more licensed RF channels and said one or more unlicensed RF channels.
13. A method of providing wireless service using one or more licensed radio frequency (RF) channels and one or more unlicensed RF channels via a system comprising a controller and a radio point, wherein the radio point is associated with at least one antenna and remotely located from the controller, wherein the radio point is communicatively coupled to the controller, wherein the controller and the radio point are configured to implement a base station in order to provide wireless service to a plurality of user equipment (UEs) on a primary cell using said one or more licensed RF channels, wherein the controller is communicatively coupled to a core network of a wireless service provider, wherein the radio point is configured to transmit and receive RF signals to and from the UEs using said one or more licensed RF channels, the method comprising:
scheduling, by the controller, transmissions on said one or more licensed RF channels and said one or more unlicensed RF channels;
using, by the radio point, a listen-before-talk (LBT) channel access process to gain access to said one or more unlicensed RF channels; and
in response to a request sent by the controller to radio point to perform the LBT channel access process in order to attempt to gain access to said one or more unlicensed RF channels in order to transmit a burst starting at or before a first transmission time interval (TTI):
if the radio point is successful in gaining access to said one or more unlicensed RF channels in order to transmit the burst starting at or before the first TTI, transmitting, on said one or more unlicensed RF channels, the burst starting at or before the first TTI; and
if the radio point is unsuccessful in gaining access to said one or more unlicensed RF channels in order to transmit the burst starting at or before the first TTI, not transmitting, on said one or more unlicensed RF channels, the burst starting at or before the first TTI, re-processing at least some data included in the burst for transmission starting at or before a later TTI, and transmitting the burst with the re-processed data starting at or before the later TTI.
14. A system to provide wireless service using one or more licensed radio frequency (RF) channels and one or more unlicensed RF channels, the system comprising:
a controller; and
a radio point;
wherein the radio point is associated with at least one antenna and remotely located from the controller, wherein the radio point is communicatively coupled to the controller;
wherein the controller and the radio point are configured to implement a base station to provide wireless service to a plurality of user equipment (UEs) on a primary cell using said one or more licensed RF channels;
wherein the controller is configured to schedule transmissions on said one or more licensed RF channels and said one or more unlicensed RF channels;
wherein the controller is communicatively coupled to a core network of a wireless service provider;
wherein the radio point is configured to transmit and receive RF signals to and from the UEs using said one or more licensed RF channels;
wherein the radio point is configured to transmit RF signals to at least some of the UEs using said one or more unlicensed RF channels and wherein the radio point is configured to use a listen-before-talk (LBT) channel access process to gain access to said one or more unlicensed RF channels;
wherein the radio point is configured do the following in response to a request sent by the controller to the radio point to perform the LBT channel access process to attempt to gain access to said one or more unlicensed RF channels in order to transmit a burst starting at or before a first transmission time interval (TTI), the burst including first data scheduled to be transmitted before or during the first TTI:
if the radio point is successful in gaining access to said one or more unlicensed RF channels in order to transmit the burst starting at or before the first transmission time interval (TTI), transmit, on said one or more unlicensed RF channels, the burst starting at or before the first TTI; and
if the radio point is unsuccessful in gaining access to said one or more unlicensed RF channels in order to transmit the burst starting at or before the first TTI, not transmit, on said one or more unlicensed RF channels, the first data as a part of the burst and transmit, on said one or more unlicensed RF channels, other data scheduled to be transmitted during the burst after the first TTI; and
wherein the controller is configured to retransmit from the radio point, on said one or more unlicensed RF channels, the first data in response to a failure to receive at the controller an acknowledgment sent from a UE in response to receiving the first data.
15. The system of claim 14 , wherein the controller is configured to retransmit from the radio point, on said one or more unlicensed RF channels, the first data in response to a failure to receive at the controller an acknowledgment sent from a UE, one said one or more licensed RF channels, in response to receiving the first data.
16. The system of claim 14 , wherein if the radio point is unsuccessful in gaining access to said one or more unlicensed RF channels in order to transmit the burst starting at or before the first TTI, sending a failure indication to the controller; and
wherein the controller, in response to receiving the failure indication, altering the scheduling of data to be transmitted during the burst to reflect a delay in gaining access to said one or more unlicensed RF channels.
17. The system of claim 14 , wherein Layer 1 processing for an air interface used for communicating using said one or more unlicensed RF channels is split between the controller and the radio point.
18. The system of claim 14 , wherein Long-Term Evolution (LTE) Licensed-Assisted Access (LAA) is used for communicating using said one or more unlicensed RF channels.
19. The system of claim 14 , further comprising a plurality of radio points;
wherein each of the radio points is associated with a respective at least one antenna and remotely located from the controller, wherein the plurality of radio points is communicatively coupled to the controller.
20. The system of claim 19 , wherein all of at least some of the radio points are configured to transmit and receive RF signals to and from the UEs using a same primary cell to transmit and receive RF signals on said one or more licensed RF channels; and
wherein each of said at least some of the radio points is configured to transmit RF signals using a respective different secondary cell using said one or more unlicensed RF channels.
21. The system of claim 19 , wherein the system comprises a plurality of controllers; and
wherein each individual controller included in the plurality of controllers is:
associated with a respective different set of radio points;
configured to use a respective primary cell associated with only said individual controller to provide wireless service using said one or more licensed RF channels; and
configured to use a respective different secondary cell for each radio point that is used by said individual controller to provide wireless service using said one or more unlicensed RF channels.
22. The system of claim 19 , wherein the system comprises a plurality of controllers; and
wherein the plurality of controllers is:
associated with a same set of radio points;
configured to all use a same primary cell to provide wireless service using said one or more licensed RF channels; and
configured to use a respective different secondary cell for each radio point that is used by the controllers to provide wireless service using said one or more unlicensed RF channels.
23. The system of claim 19 , wherein the system comprises a plurality of controllers;
wherein the controllers are configured to schedule transmissions on said one or more licensed RF channels and said one or more unlicensed RF channels; and
wherein the controllers are configured to coordinate scheduling of transmissions on said one or more unlicensed RF channels.
24. The system of claim 23 , wherein the controllers are configured to coordinate the use of the LBT channel access process among the radio points.
25. The system of claim 14 , wherein the controller is communicatively coupled to the radio point using a switched ETHERNET network.
26. The system of claim 14 , wherein the radio point comprises at least one of:
a radio point configured to use only said one or more licensed RF channels;
a radio point configured to use only said one or more unlicensed RF channels; and
a radio point configured to use both said one or more licensed RF channels and said one or more unlicensed RF channels.
27. A method of providing wireless service using one or more licensed radio frequency (RF) channels and one or more unlicensed RF channels via a system comprising a controller and a radio point, wherein the radio point is associated with at least one antenna and remotely located from the controller, wherein the radio point is communicatively coupled to the controller, wherein the controller and the radio point are configured to implement a base station in order to provide wireless service to a plurality of user equipment (UEs) on a primary cell using said one or more licensed RF channels, wherein the controller is communicatively coupled to a core network of a wireless service provider, wherein the radio point is configured to transmit and receive RF signals to and from the UEs using said one or more licensed RF channels, the method comprising:
scheduling, by the controller, transmissions on said one or more licensed RF channels and said one or more unlicensed RF channels;
using, by the radio point, a listen-before-talk (LBT) channel access process to gain access to said one or more unlicensed RF channels;
doing the following in response to a request sent by the controller, to the radio point, to perform the LBT channel access process in order to attempt to gain access to said one or more unlicensed RF channels in order to transmit a burst starting at or before a first transmission time interval (TTI), the burst including first data scheduled to be transmitted before or during the first TTI:
if the radio point is successful in gaining access to said one or more unlicensed RF channels in order to transmit the burst starting at or before the first transmission time interval (TTI), transmitting, on said one or more unlicensed RF channels, the burst starting at or before the first TTI; and
if the radio point is unsuccessful in gaining access to said one or more unlicensed RF channels in order to transmit the burst starting at or before the first TTI, not transmitting, on said one or more unlicensed RF channels, the first data as a part of the burst and transmitting, on said one or more unlicensed RF channels, other data scheduled to be transmitted during the burst after the first TTI; and
retransmitting from the radio point, on said one or more unlicensed RF channels, the first data in response to a failure to receive at the controller an acknowledgment sent from a UE in response to receiving the first data.