Internet telephony over mobile phones is on the way - but don't hold your breath. There weren't be many commercial offerings until operators have made a major enhancement to their infrastructures, said John Giere, chief marketing officer with Lucent, and that won't be until 2007 at the earliest.

He said that most operators have uplink speeds that are too slow for quality VoIP calls and that they should be looking to upgrade their networks with HSUPA (high speed uplink packet address). The technology's downlink equivalent (HSDPA) is being slowly introduced.

However, Griere said that the uplink technology is yet to be standardised and doesn't expect it to be commercially available until 2007 or 2008.

However, that timing does not fit into the VoIP-over-mobile plans of Skype Technologies and the Hutchison 3 Group.

Last month, the two companies announced a partnership to provide the world's first commercial VoIP service for mobile phones. The companies aim to begin offering service in select markets as early as this year, said Christian Salbaing, managing director of European telecommunications at Hutchison 3G.

Though Hutchison operates an IP-based network, it has not rolled out HUSPA.

In addition to HSUPA, operators planning mobile VOIP services will need to "flatten" their networks by reducing the number of components and using IP wherever possible, according to Giere. "The number of network components you have also contributes to network latency, which is a big issue with VOIP," he said.

Most GSM operators today have legacy circuit-switched networks, which tend to slow the flow of IP traffic because of their numerous network components and conversion processes, according to Giere.

In response to the need to reduce network components, Lucent has introduced a new base station system that collapses a series of network architecture layers into one component, according to Giere.

Lucent is also collaborating with Samsung Electronics in a project aimed at developing SIP (Session Initiated Protocol) client software, which is essential for offering VoIP for mobile handsets, he said.