Strife over GSM push-to-talk standard

New push-to-talk mobile phone systems being developed for packet-based GSM networks could prove to be a disruptive technology in...

New push-to-talk mobile phone systems being developed for packet-based GSM networks could prove to be a disruptive technology in more ways than one.

Equipment manufacturers are split over different interpretations and implementations of the draft push-to-talk over cellular (POC) standard from the Open Mobile Alliance (OMA) standardisation body.

Their differences threaten to fragment the market for a service that both excites and worries GSM operators. While many view the walkie-talkie-like service as a huge opportunity to expand their voice offerings, others fear it could cannibalise their highly lucrative phone business.

Push-to-talk technology can be a relatively inexpensive, simple way to use mobile phones for immediate voice communications.

In its simplest form, the technology allows customers to use their mobile phones as walkie-talkies. By pressing and holding down a button, they can talk instantly to one or more participants without having to make a dial-up call.

Moving quickly to capture a slice of what they expect to be a huge market, equipment makers have developed pre-standard POC handsets and network servers ahead of the OMA standard, which is expected by the end of this year.

Nokia, Samsung, Siemens, Sony Ericsson and Ericsson are all OMA members and are participating in the standardisation work on POC.

The problem, according to Tapio Heikkilä, director of business development at Nokia's network division, is that their pre-standardised systems are not fully interoperable.

Differences remain on the final drafting of the OMA push-to-talk standard.

Nokia believes the OMA draft specification from August 2003 lacks some important functionality and is not fully aligned with the 3GPP (3rd Generation Partnership Program) specifications, among other things, according to Heikkilä.

While Heikkilä acknowledged that Nokia's POC technology differs slightly from the August 2003 specification largely supported by the other group of vendors, he refuses to call the system a proprietary standard.

"I can't speak on behalf of the other manufacturers but I can say that our system is very close to the standard that OMA plans to define," he said. "All pre-standard systems, including ours, will need to be compliant with the OMA standard."

Confusion over standards is the last thing the industry wants, said Harry Strasser, chief technology officer at Siemens' wireless division, Siemens Mobile.

"If you have different systems in the market, you threaten to fragment it," he said. "With our initiative, we hope to ease network interoperability, which is essential for POC to establish scale. We hope to extend this interoperability to Nokia."

On 16 March, Ericsson, Motorola, Siemens and Sony Ericsson announced the first joint interoperability tests of their POC systems and plans to introduce the first pre-standard, interoperable products in the second quarter of 2004.

Nokia also announced an "initiative" to enable operators to use its POC technology, which is not interoperable with the other group's. The company said it plans to introduce a protocol converter in its server software, allowing its POC systems to be interoperable with those of the other four suppliers. Nokia added it expected these companies to make their systems interoperable with its system.

Meanwhile, Orange Personal Communications Services has chosen to introduce a push-to-talk service over its voice-centric, circuit-switched GSM network, using proprietary technology from Kodiak Networks.

The circuit-switched system will give Orange "an early-mover advantage", said Ian Pond, the company's vice-president of customer marketing. By introducing the service to the market early, Orange hopes to show customers the benefits and gain experience.

Orange has left the option open to launch a packet-based push-to-talk service at a later time.

John Blau writes for IDG News Service

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