Control of handover based on remaining inactivity timer duration

A method for controlling handover in a wireless communication system when a user equipment device (UE) is served by a first base station, the method comprising:

• receiving by the first base station from the UE a measurement report indicating that the UE is within threshold strong coverage of a second base station, wherein the first base station is configured to respond to the measurement report by (a) engaging in handover signaling with the second base station to facilitate connected-mode handover of the UE from the first base station to the second base station and then (b) transmitting to the UE a handover command message directing the UE to transition from being served by the first base station to being served by the second base station;
• and
• responsive to receipt of the measurement report, (a) predicting by the first base station that, before the first base station would send the handover command message to the UE, an inactivity timer for the UE will expire, wherein the inactivity timer times absence of user-plane communication between the UE and the first base station, and wherein expiration of the inactivity timer would trigger transition of the UE from the connected mode to an idle mode, and (b) responsive to the predicting, forgoing by the base station the connected-mode handover of the UE to the second base station and, instead, allowing by the first base station the inactivity timer to expire, whereby, after transition by the UE from the connected mode to the idle mode, the UE could then engage in idle-mode handover from the first base station to the second base station.

A base station operable in a wireless communication system to control handover of a user equipment device (UE) served in a connected mode by the base station, the base station comprising:

• a wireless communication interface, including a radio and an antenna structure, for engaging in air interface communication;
• a network communication interface through which to communicate with a neighboring base station;
• and
• a controller comprising a processing unit, data storage, and program instructions stored in the data storage and executable by the processing unit,
• wherein the controller is configured to apply an inactivity timer that times absence of user-plane communication between the UE and the base station, and wherein expiration of the inactivity timer triggers transition of the UE from the connected mode to an idle mode, and
• wherein the controller is further configured to detect a trigger for handover of the UE from the base station to the neighboring base station and, in response to detecting the trigger, (a) to predict whether the inactivity timer will expire before the base station would direct the UE to engage in the handover and (b) based on the predicting, to control the handover,
• wherein controlling the handover based on the predicting includes (i) if the predicting is that the inactivity timer will not expire before the base station would direct the UE to engage in the handover, then causing the base station to engage in handover signaling with the neighboring base station to facilitate the handover and then directing the UE to engage in the handover and (ii) if the predicting is that the inactivity timer will expire before the base station directs the UE to engage in the handover, then causing the base station to forgo engaging in the handover signaling with the neighboring base station to facilitate the handover and causing the base station to instead allow the inactivity timer to expire.