July/Aug 2005

Anyone pining for the disappearing days of two-way half-duplex radios, or 'walkie-talkies', where you had to press a button before speaking, will probably warm to the notion of push-to-talk over cellular, or PoC.

Not that it's a backward-looking technology. The mobile phone industry regards PoC as a way of encouraging customers to stay connected longer, which will be good news for the network operators.

Essentially PoC offers subscribing mobile users the ability to connect to another individual or a group of individuals at the press of a single button. Push once to connect; a second time to speak. It's a kind of audio conferencing on mobiles, with elements of instant messaging involved as well (indeed, instant messages can be sent while a conference call is under way).

PoC is already available in some markets, notably the US, where network operator Nextel has long offered a service called Direct Connect, and four other systems are now also live. According to GSA (the Global mobile Suppliers Association), there are already 15 commercial services in Europe, plus 11 in Asia and two in the Middle East.

 

However, interoperability of equipment has been elusive, and the industry has been waiting for the emergence of universal standards.

Such standards have been under development for several years under the auspices of the Open Mobile Alliance, based partly upon work originally done by Motorola, Siemens and the old Ericsson company. It now looks as though these efforts are coming to fruition, and this summer several handset and manufacturers and software suppliers have announced that they now have new OMA-compliant commercial products ready.

Among them are Nokia, Motorola and Esmertec, the third-party developer, which has adopted a software-based solution for both 2.5G and 3G handsets. Nokia is believed to have trials under way with around 30 user groups, and has just been appointed by Vodafone to roll out a service in Sweden.

Altogether, GSA says 57 phone models by 10 suppliers are compatible, and most new models launched in future will have this feature built in.

It's not clear yet whether the emergence of the new standard will result in a rush to offer such services, which are complex for network operators to administer, but if they see sufficient demand, push-to-talk could soon proliferate.