Enhancement on radio link failure report to record necessary timing details for a dual-threshold handover trigger event

摘要

A system and method in which a Radio Link Failure, RLF, report from a User Equipment, UE, provides system time-based timestamps to enable a source node to correctly analyze the real cause of an RLF associated with a handover. The timestamps are provided for the latest fulfillment of each event-specific entering condition associated with a handover-triggering event and for the occurrence of the RLF. The recorded timestamps are sent as part of RLF-reporting information to be forwarded to the source node to assist the source node in adjusting event-specific threshold(s) as well as other non-threshold related handover parameters such as the Time To Trigger, TTT, period, the time delay between a UE's transmission of its Measurement Report and the source node's transmission of the handover command, and the like, to reduce similar RLFs in the future. The generation of timestamps does not waste the UE's processing resources or battery power.

主权项

1. A method of reporting an occurrence of a Radio Link Failure (RLF) associated with a handover (HO) of a User Equipment (UE) by a source node to a target node, wherein the method comprises performing the following by the UE:
for each event-specific entering condition associated with a Measurement Report-triggering event related to the HO, storing a respective timing indication for only a most recent fulfillment of each corresponding event-specific entering condition; storing a failure time-stamp for the occurrence of the RLF; and sending RLF-reporting information to the target node, wherein the RLF-reporting information contains each stored timing indication and the stored failure time-stamp; wherein there is a plurality of event-specific entering conditions associated with the Measurement Report-triggering event, and wherein the UE performs the following as part of storing the respective timing indication:
storing a triggering time-stamp for only the most recent fulfillment of a first one of the plurality of event-specific entering conditions, wherein the triggering time-stamp is based on a reference time recognized by the source node: andstoring a respective time duration value for only the most recent fulfillment of each remaining event-specific entering condition in the plurality of event-specific entering conditions, wherein the respective time duration value is measured with reference to the triggering time-stamp; and wherein the reference time is one of the following:
a system time of the source node;an absolute time used within a source cell associated with the source node:a network-wide common time available throughout a carrier network associated with the source node; ora time in a Global Navigation Satellite System (GNSS) format.