Sufficient numbers of reliable, dual-mode wideband CDMA/GSM handsets are the key to the success of third generation (3G) mobile data services, now that problems of network capacity and management have been resolved, according to Nokia.

"Wideband CDMA networks are well designed and implemented. Problems are not down to a lack of capacity but to immature handsets where compromises have been made. There are still interoperability issues between circuit switched voice and packet switched data," said Kari Tutti, Nokia's vice president of multimedia communications.

Nokia also said that it has no plans to integrate video telephony functions into its 3G handsets, for technical reasons. It will instead concentrate on supporting the same applications currently used on GPRS and GSM networks.

"We do not see that video telephony is viable from either a demand or a technical point of view," said Olli Oittinen, vice president of marketing and sales for Nokia core networks.

Mobile operators such as O2, Vodafone and Orange have said they will be ready to start offering commercial 3G services to UK subscribers by the beginning of next year, although none have yet said whether they will support video telephony or not.

Meanwhile, Jersey Telecom will establish a 3G network in the Channel Islands by April, said the carrier's technology and planning director Jerry Rabaste. He added that technical issues such as cell breathing, call handover and voice prioritisation, as well as handset interoperability, may yet prove ongoing problems for operators.