Automatic antenna selection for mesh backhaul network nodes
View Patent ↗Methods and devices related to wireless networking. A wireless device has multiple directional antennas and multiple backhaul radio modules which provide point to point wireless links with other wireless devices. Each radio module can use any one of the available directional antennas to link to one other routing device. Antennas are automatically selected for each wireless device by merely setting one device in a “hunt” mode and setting another device in a “listen” mode. Devices in a hunt mode cycle through the available antennas by sequentially transmitting transmit messages to devices in the listen mode using each of the available antennas in turn. Devices in the listen mode also cycle through their available antennas by sequentially “listening” for transmit messages. A listen mode device, receives transmit messages on each of its available antennas, and, after gathering the relevant data, determines which of its antennas is best suited for communicating with the hunt mode device. The listen mode device antenna which is best suited is then used to transmit a response message to the hunt mode device. This listen mode device antenna is thus configured for communicating with the hunt mode device. Similarly, when the hunt mode device receives the response message, it designates its antenna which transmitted the transmit message as being configured for communications with the listen mode device.
1. A method for selecting antennas for use by a first wireless device for communicating with a second wireless device and for selecting antennas for use by said second wireless device for use in communicating with said first wireless device, said first and second wireless devices each having a plurality of antennas, the method comprising:
a) configuring said first wireless device to operate in a hunt mode, said hunt mode causing said first wireless device to send transmit messages to said second wireless device, said transmit messages containing information for uniquely identifying said first wireless device to said second wireless device as an origin of said transmit messages;
b) configuring said second wireless device to operate in a listen mode, said listen mode causing said second wireless device to await transmit messages from said first wireless device, said second wireless device being configured to reject messages not originating from said first wireless device;
c) executing the following steps on said first wireless device:
c1) selecting a first selected antenna at said first wireless device from said plurality of antennas at said first wireless device;
c2) transmitting transmit messages from said first wireless device using said first selected antenna, said transmit messages indicating an identity of said first selected antenna;
c3) determining if response messages from said second wireless device have been received by said first wireless device and determining if a timer for said first selected antenna has expired;
c4) in the event said response messages have been received by said first wireless device from said second wireless device, designating one of said plurality of antennas on said first wireless device as being for use in communications with said second wireless device based on contents of said response messages;
c5) in the event said timer has expired, repeating steps c1)–c5) for each one of said plurality of antennas on said first wireless device,
d) concurrently with steps c1)–c5) executing the following steps on said second wireless device:
d1) selecting a second selected antenna at said second wireless device from said plurality of antennas at said second wireless device;
d2) receiving transmit messages at said second wireless device using said second selected antenna;
d3) determining a quality of said transmit messages and saving data related to said quality for said second selected antenna;
d4) determining a quality of said transmit messages from different antennas on said first wireless device and saving data related to said quality for said different antennas on said first wireless device;
d5) repeating steps d2)–d4) for each of said plurality of antennas on said second wireless device;
d6) designating one of said plurality of antennas on said second wireless device as being for use in communicating with said first wireless device based on said data saved in step d3);
d7) designating one of said plurality of antennas on said first wireless device as being for use in communicating between said first wireless device and said second wireless device based on data saved in step d4);
d8) transmitting response messages from said second wireless device to said first wireless device using an antenna designated in step d4), said response messages uniquely identifying said second wireless device as an origin of said response messages, said response messages indicating which of said plurality of antennas on said first wireless device is designated as being for use by said first wireless device in communicating between said first wireless device and said second wireless device.
2. A method according to claim 1 wherein steps d2)–d4) are repeated N times for each of said plurality of antennas on said second wireless device, N being a natural number.
3. A method according to claim 1 wherein at least one of said plurality of antennas is a directional antenna.
4. A method according to claim 1 wherein step d4) includes calculating a metric indicative of a transmission quality of a signal from said first wireless device.
5. A method according to claim 1 wherein said quality relates to a quantitative measurement of a suitability of said second selected antenna for communications with said first wireless device.
6. A method according to claim 1 wherein step d4) includes calculating at least one metric selected from a group comprising:
signal strength of a signal from said first wireless device;
bit error rate;
packet error rate;
soft decision threshold;
delay spread; and
interference.
7. A method according to claim 1 further including the step of checking a global timer on said first wireless device, step c5) being executed in the event said global timer has not expired, an expiry of said global timer indicating an error in said first wireless device.
8. A method according to claim 1 wherein at least one of said first wireless device and said second wireless device is a node in a wireless backhaul network.