GRS is designed to interoperate with PMR services (as used by the emergency services and others), and Telstra is working with mobile device manufacturers to design a prototype that would combine GRS and PMR functions in a single device.
But David Borth, corporate vice president, advanced technology and research at Motorola's enterprise mobility solutions division, told iTWire that a number of obstacles mean it could be five or 10 years before public safety communications are routinely carried over cellular networks.
The underlying idea is far from new, and was co-invented by Motorola, he said, but certain features are essential for this application.
Push-to-talk over cellular links is an established but not widely used technology. The main problem is that emergency services need low latency, and the current 0.5 to one second is just not acceptable.
What other issues are there? Please read on.
(The two relevant standards are the European-originated TETRA, and P25. Borth points out that while public safety users are represented in the P25 standards committees, the cellular mobile standards are the domain of equipment manufacturers and carriers.)
Another question that has to be addressed is whether public safety users should be able to pre-empt mobile capacity in emergency situations. The answer isn't obvious, as other users have good reasons for using the network at such times.
Consequently, Motorola's position is that the adoption of a GRS-style system could be five to 10 years away, and even then users in rural areas that primarily need reliable voice communications will find P25 will still be adequate.