I've updated the way the mobile spawning works in Uprising.
By default the spawning point is where you start on the island/map. The team leader carries a satellite phone, which when deployed acts as a mobile spawn point for the team (as well as a way to communicate to outside intelligence etc.)
When the satellite phone is deployed another team member can now pack up the phone and take possesion of it.
If a player is killed whilst carrying the phone, the phone will be dropped and can be picked up by another player. So it is important to let your team know if you are the one with the satellite phone so as they can retrieve it.
If you make contact with the resistance fighters on the island, they may offer you a safehouse. This then becomes the default spawn point for the team. However the satellite phone will always take priority over the safehouse.