Carrier sense multiple access (CSMA) for multiple user, multiple access, and/or MIMO wireless communications
View Patent ↗Carrier sense multiple access (CSMA) for multiple user, multiple access, and/or MIMO wireless communications. In wireless communication systems that operate in supporting communications via one or more clusters, appropriate determination of when to begin making such transmissions on one or more clusters is made in accordance with intelligent carrier sense multiple access (CSMA) that may be performed in a number of different ways. In accordance with this, a cluster may be any combination composed of one or more channels among one or more bands. In supporting multi-cluster access, CSMA may be performed in selecting a primary cluster and performing backoff (e.g., countdown) thereon. After backoff is finished for the primary cluster, and the availability of one or more others clusters is checked, transmissions may be made using the available clusters. Alternatively, backoff may be made for each or multiple (a subset of) clusters or even individually for each respective cluster.
1. A method for execution by a wireless communication device, the method comprising:
computing a first backoff start count to perform a first backoff for a first of a plurality of clusters that is a primary cluster employed for all wireless signaling within a carrier sense multiple access/collision avoidance (CSMA/CA) communication system that includes the wireless communication device when the primary cluster is detected as being idle;
when the first backoff is completed after a countdown from the first backoff start count reaches zero, computing a second backoff start count to perform a second backoff for the plurality of clusters and determining whether the plurality of clusters are idle, wherein the plurality of clusters being a plurality of mappings of orthogonal frequency division multiplexing (OFDM) tones within a corresponding at least one channel among a corresponding at least one frequency band;
after completion of the second backoff and when the plurality of clusters is idle, via a communication interface of the wireless communication device, transmitting at least one signal to at least one additional wireless communication device using at least one of the first and a second of the plurality of clusters; and
when the first and the second of the plurality of clusters is idle for a predetermined amount of time, via the communication interface of the wireless communication device, transmitting the at least one signal or at least one additional signal to at least one additional wireless communication device using at least one of the first and the second of the plurality of clusters.
2. The method of claim 1 further comprising:
computing a plurality of backoff start counts for each respective cluster of the plurality of clusters such that each respective one of the plurality of backoff start counts corresponds to a respective one of the plurality of clusters;
for each respective cluster of the plurality of clusters, when a respective backoff corresponding to respective cluster is completed after a corresponding countdown from the respective backoff start count reaches zero, determining whether the respective cluster is idle; and
for each respective cluster of the plurality of clusters, when the respective cluster determined is idle, transmitting the at least one signal or at least one additional signal to the at least one additional wireless communication device using the respective cluster.
3. The method of claim 1 , wherein the wireless communication device is a first wireless station (STA), and the at least one additional wireless communication device is a second STA.
4. The method of claim 1 further comprising:
when the first of the plurality of clusters is idle for a first predetermined amount of time, transmitting the at least one signal to at least one additional wireless communication device using the first of the plurality of clusters; and
when the second of the plurality of clusters is idle for a second predetermined amount of time, transmitting the at least one signal or at least one additional signal to the at least one additional wireless communication device using the second of the plurality of clusters.
5. The method of claim 1 further comprising:
while transmitting the at least one signal to the at least one additional wireless communication device using the at least one of the first and the second of the plurality of clusters, determining whether a third of the plurality of clusters is idle; and
when the third of the plurality of clusters is idle, transmitting the at least one signal or at least one additional signal to the at least one additional wireless communication device using at least one of the first, the second, and the third of the plurality of clusters.
6. The method of claim 1 further comprising:
after transmitting the at least one signal, computing at least one additional backoff start count for the first of the plurality of clusters to perform subsequent backoff.
7. The method of claim 1 further comprising:
operating a subset or all of a plurality of antennae of the communication interface to transmit a plurality of signals, respectively, to a plurality of additional wireless communication devices using a subset or all of the plurality of clusters.
8. The method of claim 1 , wherein the at least one signal is a multiple input multiple output (MU-MIMO) frame or an orthogonal frequency division multiple access (OFDMA) frame.
9. The method of claim 1 , wherein the wireless communication device is an access point (AP), and the at least one additional wireless communication device is a wireless station (STA).
10. A method for execution by a wireless communication device, the method comprising:
computing a first backoff start count to perform a first backoff for a first of a plurality of clusters that is a primary cluster employed for all wireless signaling within a carrier sense multiple access/collision avoidance (CSMA/CA) communication system including the wireless communication device when the primary cluster is detected as being idle;
computing a second backoff start count to perform a second backoff for the plurality of clusters when the plurality of clusters is detected as being idle after completion of the first backoff, wherein the plurality of clusters being a plurality of mappings of orthogonal frequency division multiplexing (OFDM) tones within a corresponding at least one channel among a corresponding at least one frequency band;
when the first backoff corresponding to the primary cluster is completed after a first countdown from the first backoff start count reaches zero, monitoring for any first activity on the primary cluster;
when the second backoff corresponding to the plurality of clusters is completed after a second countdown from the second backoff start count reaches zero, monitoring for any second activity on the plurality of clusters; and
when the monitoring fails to detect any first activity and any second activity for a predetermined period of time, via a communication interface of the wireless communication device, transmitting at least one signal to at least one additional wireless communication device using the first and a second of the plurality of clusters.
11. The method of claim 10 , wherein the wireless communication device is a first wireless station (STA), and the at least one additional wireless communication device is a second STA.
12. The method of claim 10 further comprising:
operating a subset or all of a plurality of antennae of the communication interface to transmit a plurality of signals, respectively, to a plurality of additional wireless communication devices using a subset or all of the plurality of clusters.
13. The method of claim 10 further comprising:
after transmitting the at least one signal, computing at least one additional backoff start count for the first of the plurality of clusters to perform subsequent backoff.
14. The method of claim 10 , wherein the at least one signal is a multiple input multiple output (MU-MIMO) frame or an orthogonal frequency division multiple access (OFDMA) frame.
15. The method of claim 10 , wherein the wireless communication device is an access point (AP), and the at least one additional wireless communication device is a wireless station (STA).
16. An apparatus comprising:
a processor configured to:
compute a first backoff start count to perform a first backoff for a first of a plurality of clusters that is a primary cluster employed for all wireless signaling within a carrier sense multiple access/collision avoidance (CSMA/CA) communication system including the apparatus when the primary cluster is detected as being idle; and
when the first backoff is completed after a countdown from the first backoff start count reaches zero, compute a second backoff start count to perform a second backoff for the plurality of clusters and determine whether the plurality of clusters are idle, wherein the plurality of clusters being a plurality of mappings of orthogonal frequency division multiplexing (OFDM) tones within a corresponding at least one channel among a corresponding at least one frequency band; and
a communication interface configured to:
transmit, after completion of the second backoff and when the plurality of clusters is idle, transmit at least one signal to at least one wireless communication device using at least one of the first and a second of the plurality of clusters; and
when the first and the second of the plurality of clusters is idle for a predetermined amount of time, transmit the at least one signal or at least one additional signal to at least one additional wireless communication device using at least one of the first and the second of the plurality of clusters.
17. The apparatus of claim 16 , wherein the processor is further configured to:
compute a plurality of backoff start counts for each respective cluster of the plurality of clusters such that each respective one of the plurality of backoff start counts corresponds to a respective one of the plurality of clusters;
for each respective cluster of the plurality of clusters, when a respective backoff corresponding to respective cluster being completed after a corresponding countdown from the respective backoff start count reaches zero, determine whether the respective cluster being idle; and
for each respective cluster of the plurality of clusters, when the respective cluster determined as being idle, direct the communication interface to transmit the at least one signal or at least one additional signal to the at least one additional wireless communication device using the respective cluster.
18. The apparatus of claim 16 , wherein the processor is further configured to:
compute at least one additional backoff start count for the first of the plurality of clusters for performing subsequent backoff after the at least one signal being transmitted.
19. The apparatus of claim 16 , wherein the at least one signal is a multiple input multiple output (MU-MIMO) frame or an orthogonal frequency division multiple access (OFDMA) frame.
20. The apparatus of claim 16 further comprising:
an access point (AP), wherein the at least one additional wireless communication device is a wireless station (STA).