Industry struggles over GSM push-to-talk standard

New push-to-talk mobile phone systems being developed for packet-based GSM (Global System for Mobile Communications) 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) standardization 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 cannibalize 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.

In the one camp is Nokia Corp. together with Samsung Electronics Co. Ltd., which has agreed to license POC technology from the Espoo, Finland, mobile phone and infrastructure manufacturer. In the other is Motorola Inc., Siemens AG, Sony Ericsson Mobile Communications AB and Telefonaktiebolaget LM Ericsson.

All six companies are OMA members and are participating in the standardization work on POC. The problem, according to Tapio Heikkilä, director of business development at Nokia’s network division, is that their pre-standardized systems aren’t fully interoperable. And differences remain on the final drafting of the OMA push-to-talk standard.

On March 16, two days before the official start of the Cebit trade show in Hanover, Germany, 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.

On the same day, Nokia announced an “initiative” to enable operators to use its POC technology, which isn’t interoperable with the other group’s. Reaching out, 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 vendors. Nokia added it expects these companies to make their systems interoperable with its system.

Why the two directions? Nokia, which has been fast out of the blocks on POC, 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. The Finnish company’s system addresses these issues, he said.

While Heikkilä acknowledges 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 Finnish vendor’s 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, according to Harry Strasser, chief technology officer (CTO) 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.”

At Cebit, executives from two of Europe’s largest mobile operators named standards as a hurdle to introducing POC service.

Friedrich Joussen, chief operating officer of Vodafone D2 GmbH, said that while the German operator is currently “studying” the technology, it wouldn’t move ahead without a standard.

A similar view was shared by Hamid Akhavan, CTO at T-Mobile International AG & Co. KG, the wireless arm of German telco Deutsche Telekom AG. Akhavan referred to push-to-talk as a developing technology, one that isn’t “mature” enough to introduce commercially. The operator, he said, prefers to wait for a standard before launching service.

To get a jump on the rest, however, U.K. mobile phone company Orange Personal Communications Services Ltd. has chosen to introduce this month a push-to-talk service over its voice-centric, circuit-switched GSM network, using proprietary technology from Kodiak Networks Inc. in San Ramon, California.

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, he said.

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