US Patent 11178195 Expedited retransmission during call setup

Systems, devices, and techniques described herein relate to selectively implementing an expedited retransmission time. In some examples, a call setup message is transmitted to a first network system associated with a first network access technology. A transfer request may be received from the first network system. The transfer request may indicate handover or redirection to a second network system associated with a second network access technology. Upon expiration of the expedited retransmission time after receiving the transfer request, the call setup message can be retransmitted to the second network system.