Dynamic selection of a receive antenna pattern

Abstract

An access point that performs dynamic selection of an electronic-device-specific receive antenna pattern of an antenna for use when receiving a frame from an electronic device in a WLAN is described. In particular, during operation the access point may determine the receive antenna pattern of the antenna that is used when receiving the frame from the electronic device. Then, the access point may store, in memory, information that specifies the receive antenna pattern. Moreover, when the access point predicts that the electronic device will transmit a frame to the access point within a subsequent time interval, the access point may select the receive antenna pattern and may set an antenna pattern of the antenna to the receive antenna pattern. Next, the access point may receive the frame from the electronic device using the receive antenna pattern.

What is claimed is: 
     
       1. An access point, comprising:
 an antenna node configured to couple to an antenna; and 
 an interface circuit, coupled to the antenna node, configured to wirelessly communicate with at least an electronic device in a wireless local area network (WLAN), wherein the access point is configured to dynamically select a receive antenna pattern of the antenna by performing operations comprising:
 determining the receive antenna pattern of the antenna that is used when receiving a first frame associated with the electronic device, wherein the receive antenna pattern is electronic-device specific and has increased directionality relative to an omnidirectional antenna pattern; 
 storing, in memory in the access point, information that specifies the receive antenna pattern; and 
 when the access point predicts, based at least in part on a type of control frame which is received after the receive antenna pattern is determined, that the electronic device will transmit the first a second frame to the access point within a subsequent time interval:
 selecting the receive antenna pattern and setting an antenna pattern of the antenna to the receive antenna pattern; and 
 receiving the first second frame associated with the electronic device using the receive antenna pattern, wherein the second frame is different from the type of control frame, and 
 wherein the type of control frame is different from a request-to-send (RTS) frame and the type of control frame comprises a trigger frame. 
 
 
 
     
     
       2. The access point of  claim 1 , wherein the determining of the receive antenna pattern involves the access point:
 receiving frames associated with the electronic device, where the frames are received by the access point using different receive antenna patterns of the antenna; 
 determining values of a performance metric based at least in part on the received frames; and 
 selecting the receive antenna pattern from the receive antenna patterns based at least in part on the values of the performance metric. 
 
     
     
       3. The access point of  claim 1 , wherein the determining of the receive antenna pattern involves the access point:
 transmitting frames for the electronic device using different transmit antenna patterns of the antenna; 
 receiving values of a performance metric associated with the electronic device, wherein the values of the performance metric are based at least in part on at least some of the frames that were transmitted for the electronic device; 
 selecting a transmit antenna pattern from the transmit antenna patterns based at least in part on the values of the performance metric; and 
 assigning the receive antenna pattern as the transmit antenna pattern. 
 
     
     
       4. The access point of  claim 1 , wherein the transmission by the electronic device is predicted based at least in part on the access point:
 receiving a request-to-send (RTS) the RTS frame associated with the electronic device; and 
 transmitting, in response to receiving the RTS frame, a clear-to-send (CTS) frame for the electronic device. 
 
     
     
       5. The access point of  claim 1 , wherein the transmission by the electronic device is predicted based at least in part on the access point transmitting a trigger frame for at least the electronic device operations comprise reverting to the omnidirectional antenna pattern when a time reserved by the trigger frame expires. 
     
     
       6. The access point of  claim 1 , wherein the interface circuit is configured to communicate with a second electronic device in the WLAN, and the access point is configured to:
 determining a second receive antenna pattern of the antenna that is used when receiving a second frame associated with the second electronic device; and 
 storing, in memory in the access point, information that specifies the second receive antenna pattern. 
 
     
     
       7. The access point of  claim 6 , wherein, when the access point predicts that the second electronic device will transmit the second frame to the access point within a second subsequent time interval, the access point is configured to:
 select the second receive antenna pattern; 
 set the antenna pattern of the antenna to the second receive antenna pattern; and 
 receive the second frame associated with the second electronic device using the second receive antenna pattern. 
 
     
     
       8. The access point of  claim 1 , wherein the access point comprises the antenna. 
     
     
       9. The access point of  claim 1 , wherein the antenna includes multiple antenna elements and the access point is configured to provide, to the antenna, control signals that selectively couple one or more of the antenna elements to ground to steer the antenna pattern of the antenna in a direction. 
     
     
       10. The access point of  claim 9 , wherein the antenna elements include reflectors. 
     
     
       11. The access point of  claim 1 , wherein the access point comprises:
 a processor; and 
 a memory, coupled to the processor, which stores program instructions that, when executed by the processor, the program instructions cause the access point to perform the determining and the storing. 
 
     
     
       12. A non-transitory computer-readable storage medium for use in conjunction with an access point, the computer-readable storage medium storing program instructions that, when executed by the access point, causes the access point to dynamically select a receive antenna pattern of an antenna in the access point by performing operations comprising:
 determining the receive antenna pattern of the antenna that is used when receiving a first frame associated with an electronic device in a wireless local area network (WLAN), wherein the receive antenna pattern is electronic-device specific and has increased directionality relative to an omnidirectional antenna pattern; 
 storing, in memory in the access point, information that specifies the receive antenna pattern; and 
 when the access point predicts, based at least in part on a type of a control frame which is received after the receive antenna pattern is determined, that the electronic device will transmit the first a second frame to the access point within a subsequent time interval:
 selecting the receive antenna pattern and setting an antenna pattern of the antenna to the receive antenna pattern; and 
 receiving the first second frame associated with the electronic device using the receive antenna pattern, wherein the second frame is different from the type of control frame, and 
 wherein the type of control frame is different from a request-to-send (RTS) frame and the type of control frame comprises a trigger frame. 
 
 
     
     
       13. The computer-readable storage medium of  claim 12 , wherein the determining of the receive antenna pattern involves the access point:
 receiving frames associated with the electronic device, where the frames are received by the access point using different receive antenna patterns of the antenna; 
 determining values of a performance metric based at least in part on the received frames; and 
 selecting the receive antenna pattern from the receive antenna patterns based at least in part on the values of the performance metric. 
 
     
     
       14. The computer-readable storage medium of  claim 12 , wherein the determining of the receive antenna pattern involves the access point:
 transmitting frames for the electronic device using different transmit antenna patterns of the antenna; 
 receiving values of a performance metric associated with the electronic device, wherein the values of the performance metric are based at least in part on at least some of the frames that were transmitted to the electronic device; 
 selecting a transmit antenna pattern from the transmit antenna patterns based at least in part on the values of the performance metric; and 
 assigning the receive antenna pattern as the transmit antenna pattern. 
 
     
     
       15. The computer-readable storage medium of  claim 12 , wherein the transmission by the electronic device is predicted based at least in part on the access point:
 receiving a request-to-send (RTS) the RTS frame associated with the electronic device; and 
 transmitting, in response to receiving the RTS frame, a clear-to-send (CTS) frame for the electronic device. 
 
     
     
       16. The computer-readable storage medium of  claim 12 , wherein the transmission by the electronic device is predicted based at least in part on the access point transmitting a trigger frame for at least the electronic device operations comprise reverting to the omnidirectional antenna pattern when a time reserved by the trigger frame expires. 
     
     
       17. The computer-readable storage medium of  claim 12 , wherein, when executed by the processor, the program module causes instructions cause the access point to perform operations comprising:
 determining a second receive antenna pattern of the antenna that is used when receiving a second frame associated with the second electronic device; and 
 storing, in memory in the access point, information that specifies the second receive antenna pattern. 
 
     
     
       18. The computer-readable storage medium of  claim 17 , wherein, when the program instructions are executed by the processor and when the access point predicts that the second electronic device will transmit the second frame to the access point within a second subsequent time interval, the program instructions cause the access point to perform operations comprising:
 select the second receive antenna pattern; 
 set the antenna pattern of the antenna to the second receive antenna pattern; and 
 receive the second frame associated with the second electronic device using the second receive antenna pattern. 
 
     
     
       19. A method for dynamically selecting a receive antenna pattern of an antenna in an access point, comprising:
 by the access point:
 determining the receive antenna pattern of the antenna that is used when receiving a first frame associated with an electronic device in a wireless local area network (WLAN), wherein the receive antenna pattern is electronic-device specific and has increased directionality relative to an omnidirectional antenna pattern; 
 storing, in memory in the access point, information that specifies the receive antenna pattern; and 
 when the access point predicts, based at least in part on a type of a control frame which is received after the receive antenna pattern is determined, that the electronic device will transmit the first a second frame to the access point within a subsequent time interval:
 selecting the receive antenna pattern and setting an antenna pattern of the antenna to the receive antenna pattern; and 
 receiving the second frame associated with the electronic device using the receive antenna pattern, wherein the second frame is different from the type of control frame, and 
 wherein the type of control frame is different from a request-to-send (RTS) frame and the type of control frame comprises a trigger frame. 
 
 
 
     
     
       20. The method of  claim 19 , wherein the transmission by the electronic device is predicted based at least in part on the access point:
 receiving a request-to-send (RTS) the RTS frame associated with the electronic device; and 
 transmitting, in response to receiving the RTS frame, a clear-to-send (CTS) frame for the electronic device. 
 
     
     
       21. The access point of  claim 1 , wherein, after setting an antenna pattern of the antenna to the receive antenna pattern, the access point is configured to revert the receive antenna pattern to the omnidirectional antenna pattern after the subsequent time interval. 
     
     
       22. The computer-readable storage medium of  claim 12 , wherein the operations comprise, after setting an antenna pattern of the antenna to the receive antenna pattern, reverting the receive antenna pattern to the omnidirectional antenna pattern after the subsequent time interval. 
     
     
       23. The method of  claim 19 , wherein the method comprises, after setting an antenna pattern of the antenna to the receive antenna pattern, reverting the receive antenna pattern to the omnidirectional antenna pattern after the subsequent time interval. 
     
     
       24. An electronic device, comprising:
 an antenna node configured to couple to an antenna; and   an interface circuit, coupled to the antenna node, configured to wirelessly communicate with at least a second electronic device, wherein the electronic device is configured to dynamically select a receive antenna pattern of the antenna by performing operations comprising:
 determining the receive antenna pattern of the antenna that is used when receiving a first frame associated with the second electronic device, wherein the receive antenna pattern is electronic-device specific and has increased directionality relative to an omnidirectional antenna pattern; 
 storing, in memory in the electronic device, information that specifies the receive antenna pattern; and 
 when the electronic device predicts, based at least in part on a type of control frame which is received after the receive antenna pattern is determined, that the second electronic device will transmit a second frame to the electronic device within a subsequent time interval;
 selecting the receive antenna pattern and setting an antenna pattern of the antenna to the receive antenna pattern; and 
 receiving the second frame associated with the second electronic device using the receive antenna pattern, wherein the second frame is different from the type of control frame, and 
 wherein the type of control frame is different from a request-to-send (RTS) frame and the type of control frame comprises a trigger frame.