3GPP suggests to use fresh SQNs for each subscriber. Normally it is defined as 48-bits HEX, however, only some HEX numbers are accepted. We are looking for the algorithm to produce acceptable SQN numbers. Could you please help on this ?
May you provide specific and details information for us to understand what you are looking for?
Refer to the 3GPP TS 33.102 Annex C. SQN will not be acceptable when the SQN in the UE is larger than the SQN in the core network. In such cases, you need to utilize the AUTS value in the synchronization failure message from the USIM to produce the current acceptable SQN in the USIM.