Intelligence in handover assessment for LTE/VoLTE calls to improve retainability

A network entity in a cellular network for sustaining an ongoing service when a mobile device associated with a serving cell is to be handed over by the network entity, wherein the network entity comprises:

• a transceiver for wirelessly communicating with the mobile device and for facilitating provision of the service to the mobile device in the serving cell;
• a memory for storing program instructions;
• and
• a processor coupled to the memory and the transceiver and configured to execute the program instructions, which, when executed by the processor, cause the network entity to perform the following:
• receive, from the mobile device, a list of potential target entities for handover of the mobile device;
• send a request to a target entity in the list for the handover of the mobile device, wherein the request includes all mandatory Radio Access Bearers (RABs) to be admitted by the target entity as part of supporting one or more Quality of Service Class Identifiers (QCIs) associated with the service;
• and
• perform the handover of the mobile device to the target entity only if the target entity sends a response to the request that indicates that the target entity has admitted all of the mandatory RABs.

A wireless system comprising:

• a source evolved Node B (eNB) that is configured to perform the following as part of sustaining an ongoing service when a User Equipment (UE) is to be handed over by the source eNB:
• facilitate provision of the service to the UE in a serving cell associated with the source eNB,
• receive, from the UE, a list of potential target eNBs for handover of the UE,
• determine that an attempt counter at the source eNB has a value that is less than or equal to a pre-determined number,
• in response to the determination, send a first request to a first target eNB in the list for the handover of the UE, wherein the first request includes all mandatory Radio Access Bearers (RABs) to be admitted by the first target eNB as part of supporting one or more Quality of Service Class Identifiers (QCIs) associated with the service,
• receive a first indication from the first target eNB that the first target eNB has admitted some but not all of the mandatory RABs, and
• prevent the handover of the UE to the first target eNB in response to receiving the first indication from the first target eNB;
• and
• the first target eNB that is in communication with the source eNB and configured to perform the following:
• receive the first request from the source eNB,
• perform first target eNB-specific admission control for the mandatory RABs based on first target eNB-specific available radio resources, and
• send the first indication to the source eNB based on the result of the first target eNB-specific admission control.