The technology of remote car starter apps

I got the impression that the hardware installed in your car for this includes what amounts to a cell phone receiver that receives a command from your phone via cell towers.

My co-workers insist there is satellite communication involved. That the command goes through my smart phone’s “data” system to a cell tower, up to a satellite and back down to a satellite receiver in my car.

Bonus question: do smart phone data communications travel by different routes than cell phone calls? I understand they’re not from one phone to another, but do they use anything other than cell towers and/or land lines? Oh, and let me exclude GPS signals from this – I understand that my phone can receive signals from GPS satellites.

Onstar uses the verizon wireless cellular network in the US. I don’t know about the others. There are European regulations that state in effect that the cars need to notify emergency services in case of accidents. From what I understand basically every manufacturer has chosen to do this over the cellular network. I am not sure what year new cars in Europe needed to be able to do this.

So, no satellite necessary?

None that I’m aware of. Most “smart” car remotes use the cellular signal to connect. Older types used RF.