Wi-Fi finally discovers its voice

Developments in technology and service provision are bringing voice over Wi-Fi into the mainstream

The idea of using your wireless LAN (WLAN) or a Wi-Fi hotspot to carry voice calls has been around for a long while but it isn’t yet a mainstream activity. However, various changes mean that it soon will be.

About four years ago, the Third Generation Partnership Project (3GPP) standards body, which creates 3G and GSM standards, suggested that it would be a neat idea to use Wi-Fi as an alternative way to access mobile networks.

This was quite a tricky idea because of the authentication and encryption, which are very important for public mobile networks; not to mention the problem of handing over between the different types of network. A group of interested companies then got together to thrash out the problems; they came up with what is known as Unlicensed Mobile Access (UMA). They passed the specifications to 3GPP where they were developed further. However, there hasn’t been very much activity in networks or handsets to support the technology.

Earlier this year, Nokia announced handsets that support Wi-Fi voice as well as 3G and GSM but it wasn’t clear whether they could handle the UMA protocols. This was followed by a UMA trial in the Finnish city of Oulu using a different handset, the 6136. This trial is still going on and it will be interesting to see the results. Meanwhile, in Singapore, SingTel has started a dual-mode voice service where Nokia E60, E61 and N80 handsets can be used to make VoIP calls via SingTel’s hotspots as well as the usual mobile networks. This is not true UMA because there is, as yet, no automatic handover between the networks.

BT’s Fusion service uses a special mobile phone, which allows you to make wireless voice calls via a broadband connection as well as via the usual mobile network. There is partial handover in that calls initiated via Bluetooth will transfer to GSM when you move out of range of the home base station. Handover does not occur in the other direction. The system currently uses Bluetooth radios and BT has just announced its Corporate Fusion version for businesses, which is scheduled for rollout early next year.

Wi-Fi-only handsets are now becoming available that can be used over a WLAN via various VoIP providers. These are likely to become popular when the price comes down and they can work like a normal cordless phone. Cambridge Silicon Radio’s UniVox is a prototype Wi-Fi VoIP phone that should cost less that $20 (£11) to make and have 20 hours talk time.

Taken together, these developments mean that manufacturers are getting serious about using Wi-Fi networks for voice handsets.