Controlling handover parameters based on target base station characteristics
A method and system to control UE handover is disclosed herein. A source base station serving a UE receives from the UE a measurement report that specifies a signal strength of a neighboring target base station. The source base station sets a value of a handover threshold parameter, with the set value being based at least in part on whether the target base station is a relay base station or a non-relay base station. Further, the source base station may compare the specified signal strength of the target base station to the set value of the handover threshold parameter and determine that a handover condition is satisfied. Responsive to making such a determination, the source base station may invoke handover of the UE from the source base station to the target base station.
1. A method of managing handover of a user equipment device (UE) from a source base station serving the UE to a target base station, the method comprising:
receiving a measurement report from the UE, wherein the measurement report specifies a signal strength of the target base station;
determining, based on the measurement report from the UE, that the target base station is a relay base station rather than a non-relay base station;
setting a value of a handover threshold, wherein the base station is configured by default to set the handover threshold to a first default value, and wherein setting the value of the handover threshold comprises setting the handover threshold to a second value different from the first default value based at least in part on the determination that the target base station is a relay base station rather than a non-relay base station;
determining, based on the set value of the handover threshold, that the specified signal strength of the target base station satisfies a handover condition; and
responsive to determining that the specified signal strength of the target base station satisfies the handover condition, invoking the handover of the UE from the source base station to the target base station.
2. The method of claim 1 , wherein the second value is higher than the first default value.
3. The method of claim 1 , wherein the measurement report further specifies a signal strength of the source base station, and wherein setting the value of the handover threshold comprises applying an offset to the signal strength of the source base station, wherein the offset represents how much higher than the signal strength of the source base station the signal strength of the target base station needs to be to invoke handover of the UE from the source base station to the target base station.
4. The method of claim 3 , wherein setting the handover threshold to the first default value comprises applying a first offset value to the signal strength of the source base station, and wherein setting the handover threshold to the second value comprises applying a second offset value that is higher than the first offset value to the signal strength of the source base station.
5. The method of claim 1 , wherein determining that the specified signal strength of the target base station satisfies the handover condition comprises determining that the specified signal strength of the target base station is greater than the set handover threshold value.
6. The method of claim 1 , wherein the setting comprises setting the value of the handover threshold responsive to determining that the target base station is a relay base station rather than a non-relay base station.
7. The method of claim 1 , wherein the measurement report further specifies an identifier of the target base station, and wherein the source base station determines, based on the specified identifier, that the target base station is a relay base station rather than a non-relay base station.
8. The method of claim 1 , further comprising determining a number of UEs served by the target base station, wherein setting the value of the handover threshold comprises setting the handover threshold to the second value based on both (i) the determination that the target base station is a relay base station rather than a non-relay base station and (ii) the determined number of UEs.
9. The method of claim 1 , further comprising determining a quantity of data communicated between the target base station and one or more UEs served by the target base station, wherein setting the value of the handover threshold comprises setting the handover threshold to the second value based on both (i) the determination that the target base station is a relay base station rather than a non-relay base station and (ii) the determined quantity of data.
10. A method of managing handover of a user equipment device (UE) from a source base station serving the UE to a target base station, the method comprising:
receiving a measurement report from the UE, wherein the measurement report specifies a signal strength of the target base station;
responsive to receiving the measurement report, performing a handover threshold setting process comprising:
(a) determining, based on the measurement report, that the target base station is a relay base station rather than a non-relay base station,
(b) determining that the target base station serves a threshold high extent of traffic, and
(c) setting a value of a handover threshold, wherein the base station is configured by default to set the handover threshold to a first default value, and wherein setting the value of the handover threshold comprises setting the handover threshold to a second value different from the first default value based on the target base station being a relay base station that serves the threshold high extent of traffic;
determining, based on the set value of the handover threshold, that the specified signal strength of the target base station satisfies a handover condition; and
responsive to determining that the specified signal strength of the target base station satisfies the handover condition, invoking the handover of the UE from the source base station to the target base station.
11. The method of claim 10 , wherein the measurement report further specifies a signal strength of the source base station, and wherein setting the value of the handover threshold comprises applying an offset to the signal strength of the source base station, wherein the offset represents how much higher than the signal strength of the source base station the signal strength of the target base station needs to be to invoke handover of the UE from the source base station to the target base station.
12. The method of claim 10 , wherein determining that the specified signal strength of the target base station satisfies the handover condition comprises determining that the specified signal strength of the target base station is greater than the set handover threshold value.
13. The method of claim 10 , wherein the measurement report further specifies an identifier of the target base station, and wherein the source base station determines, based on the specified identifier, that the target base station is a relay base station rather than a non-relay base station.
14. The method of claim 10 , wherein determining that the target base station serves the threshold high extent of traffic comprises determining that a number of UEs served by the target base station is threshold high, and wherein the setting comprises setting the value of the handover threshold to the second value based on both (i) the target base station being a relay base station rather than a non-relay base station and (ii) the target base station serving the threshold high number of UEs.
15. The method of claim 10 , wherein determining that the target base station serves the threshold high extent of traffic comprises determining that a quantity of data communicated between the target base station and one or more UEs served by the target base station is threshold high, and wherein the setting comprises setting the value of the handover threshold to the second value based on both (i) the target base station being a relay base station rather than a non-relay base station and (ii) the target base station communicating the threshold high quantity of data between the target base station and the one or more UEs.
16. A base station comprising:
an antenna structure for engaging in air interface communication with user equipment devices (UEs);
a backhaul communication interface for engaging in backhaul communication on a core access network; and
a controller configured to control a handover of a UE served by the base station, wherein the controller is configured to:
receive via the antenna structure a measurement report from the UE, wherein the measurement report specifies a signal strength of a neighboring base station,
determine, based on the measurement report from the UE, that the neighboring base station is a relay base station rather than a non-relay base station,
set a value of a handover threshold, wherein the controller is configured by default to set the handover threshold to a first default value, and wherein setting the value of the handover threshold comprises setting the handover threshold to a second value different from the first default value based at least in part on the determination that the neighboring base station is a relay base station rather than a non-relay base station,
determine, based on the set value of the handover threshold, that the specified signal strength of the neighboring base station satisfies a handover condition, and
based on the specified signal strength of the neighboring base station satisfying the handover condition, invoke handover of the UE to the neighboring base station.
17. The base station of claim 16 , wherein the second value is higher than the first default value.
18. The base station of claim 16 , wherein the controller is further configured to determine an extent of traffic served by the neighboring base station, and wherein setting the value of the handover threshold comprises setting the handover threshold to the second value based on both (i) the determination that the neighboring base station is a relay base station rather than a non-relay base station and (ii) the determined extent of traffic.
19. The base station of claim 18 , wherein determining the extent of traffic served by the neighboring base station comprises receiving via the backhaul communication interface a report indicating a number of UEs served by the neighboring base station, and wherein setting the value of the handover threshold to the second value based on the determined extent of traffic comprises setting the value of the handover threshold to the second value based on the indicated number of UEs.
20. The base station of claim 18 , wherein determining the extent of traffic served by the neighboring base station comprises receiving via the backhaul communication interface a report indicating a quantity of data communicated between the neighboring base station and one or more UEs served by the neighboring base station, and wherein setting the value of the handover threshold to the second value based on the determined extent of traffic comprises setting the value of the handover threshold to the second value based on the indicated quantity of data.