GSM Mobile subscriber option to select high priority call and preempt off a lower priority call after call establishment failure due to network busy
Original Publication Date: 2010-Jul-19
Included in the Prior Art Database: 2010-Jul-19
When attempting to make a GSM mobile phone call if there are no radio resources available in the cell then the subscriber will have the choice to select from an on screen menu whether they want to redial using a higher priority which will preempt off a lower priority call on the cell. This should be an optional feature ie it should be possible to turn off the option if not required. Currently if a GSM call mobile phone call is unsuccessful due to no radio resources available in the cell the call fails due to the network being busy. This idea will give the subscriber the choice to redial with a high priority. There is a priority information element in the CM Service Request message sent by the mobile that could be updated with the selected priority. There is a prerequisite that the network supports eMLPP(Enhanced Multilayer Priority and Preemption)for this functionality to work. The network operator could charge a premium rate for calls that are high priority. Currently if no radio resources are available the MS is released with a channel release(CHANNEL RELEASE (44.018) RR CAUSE IE) with cause 0 = normal release. A new cause value "No radio resources available" could be added to the channel release message. When the MS receives this cause value it would then provide the user with the opportunity to retry with a higher priority if the option is enabled in the phone.