Solution 1 (Parallel SR transmissions based on multiple SR configurations)—In this solution, the UE can support to transmit multiple SR transmissions based on different SR configurations. The multiple SR transmissions may occur on same or different cells (e.g. all on PCell or one on PCell, other on SCell or any other possible combination between multiple SCells and PCell). Hence, the new event (e.g. uplink data arrival, special event) triggers SR transmission based on a SR configuration, while current SR transmission performed based on another SR configuration.
Based on this solution, the network can derive more information from SR transmissions belonging to the same UE. For example, the network (e.g. gNB) can discover the occurrence of uplink data arrival and special event.
Solution 2 (Update SR transmission to reflect highest priority need (either new event or current buffer size))—The UE may or may not support parallel multiple SR transmissions based on different SR configurations. If UE does not support, the UE will need to stop current SR transmission for initiating SR transmission based on a SR configuration different from current used SR configuration.
Since the UE needs to reflect higher priority need in this solution, the priority between special event and uplink data arrival will need to be defined clearly. Possible options are listed below: