Systems and methods for selecting an access node and/or cell sector for handover of a wireless device
Systems and methods are described for performing handover of a wireless device to a target Access Node (AN) sector. Beam-form capable sectors of one or more target ANs may be selected from a pool of candidate sectors. At least one of the selected sectors may be prioritized (e.g., over the other sectors) based on an open beam-form seat. Handover of the wireless device from a first AN to the prioritized sector may be performed.
1. A method for performing handover of at least one wireless device to a target access node sector, the method comprising:
selecting one or more beam-form capable sectors of one or more target access nodes from a pool of candidate sectors;
prioritizing at least one of the selected sectors having a greatest number of open beam-form seats; and
performing handover of the at least one wireless device from a first access node to the prioritized sector.
2. The method of claim 1 , wherein the selected one or more beam-form capable sectors of the one or more target access nodes are within a radio range of the at least one wireless device.
3. The method of claim 1 , wherein handover of the at least one wireless device is triggered at the first access node when a beam-form load at the first access node meets or exceeds a threshold.
4. The method of claim 3 , wherein the threshold is a number of beam-form wireless devices supported at the first access node as a function of an SRS period.
5. The method of claim 3 , further comprising:
instructing the at least one wireless device to measure detectable signal properties of the one or more target access nodes, wherein the signal properties include at least one of a Channel Quality Indicator (CQI), Received Signal Strength Indicator (RSSI), and Signal-to-Interference-Plus-Noise Ratio (SINR).
6. The method of claim 3 , wherein the prioritized sector of the one or more target access nodes instructs the at least one wireless device to report an availability of uplink (UL) air-interface Sounding Reference Signal (SRS) resources at the target access node.
7. The method of claim 6 , wherein the prioritized sector of the target access node uses the reported SRS to estimate a Direction of Arrival (DoA) for a signal emanating from the at least one wireless device.
8. The method of claim 7 , wherein the prioritized sector of the target access node uses Multiple Signal Classification (MUSIC) to estimate the DoA.
9. The method of claim 8 , further comprising:
calculating beamforming weights based on the estimated DoA, wherein the calculated beamforming weights are used to direct beams and/or beam patterns toward the at least one wireless device.
10. A method for handover of at least one wireless device, the method comprising:
selecting one or more candidate sectors from a pool of neighboring access node sectors;
prioritizing the candidate sectors based on an open beam-form seat;
calculating an amount of beam-formed wireless devices for each of the prioritized candidate sectors;
selecting the prioritized candidate sector with a least amount of beam-formed wireless devices for handover of the at least one wireless device; and
performing handover of the at least one wireless device from a first sector of a first access node to the selected candidate sector.
11. The method of claim 10 , wherein the selected prioritized candidate sectors of the neighboring access node sectors are within a radio range of the at least one wireless device.
12. The method of claim 10 , wherein handover of the at least one wireless device is triggered at the first access node when a beam-form load at the first sector meets or exceeds a threshold.
13. The method of claim 12 , wherein the threshold is a number of beam-form wireless devices supported at the first sector of the first access node as a function of an SRS period.
14. The method of claim 12 , further comprising:
instructing the wireless device to measure detectable signal properties of the neighboring access node sectors, wherein the signal properties include at least one of a Channel Quality Indicator (CQI), Received Signal Strength Indicator (RSSI), and Signal-to-Interference-Plus-Noise Ratio (SINR).
15. The method of claim 12 , wherein the selected candidate sector instructs the at least one wireless device to report an availability of uplink (UL) air-interface Sounding Reference Signal (SRS) resources at a target access node.
16. The method of claim 15 , wherein the selected candidate sector uses the reported SRS to estimate a Direction of Arrival (DoA) for a signal emanating from the at least one wireless device.
17. The method of claim 16 , further comprising: calculating beamforming weights based on the estimated DoA, wherein the calculated beamforming weights are used to direct beams and/or beam patterns toward the at least one wireless device.