To: waverider who wrote (1719 ) 9/20/1999 5:00:00 PM From: Robert Read Replies (1) | Respond to of 13582
3G Roaming Highlights Standards Hurdles By Vanessa Clark 20 September 1999 The first ever roaming call was made between a commercial GSM network and a third generation system last week according to Telia Mobile and Ericsson. But the trial highlighted the standardization niggles developers will have to overcome before 3G becomes a reality. On Friday the companies successfully placed a call to a wideband-CDMA handset fitted with a GSM SIM card and operating on a 3G test system by phoning the SIM's usual GSM number. The demonstration also included the transfer of packetised traffic at speeds of up to 384 kilobytes per second, said. In addition, a user from another GSM network with a roaming agreement would also be able to roam onto the test 3G network. "This test clearly demonstrates the co-existence of GSM with 3G," said Lorentz Engstrom, senior technical advisor at Telia Mobile. "Operators can build out 3G coverage in line with market demand." But the roaming phone can only receive calls, not make them and the companies admit that there is still a way to go before seamless interworking can be achieved: Developers now have to look at the capabilities of the handset used on a 3G network, as well as the issue of SIM roaming. Initial 3G handsets will need to cope with roaming between regular GSM coverage and the so-called islands of 3G that will form as operators build out new networks. Engstrom envisages some kind of dual-band phone with seamless hand over between the two networks. But as to the features of the terminals, Engstrom says this is something being discussed with manufacturers at present. However, he said that it seems unlikely that all existing features - like three GSM bands and GPRS capabilities - will be bundled into one phone. Standardization bodies like the 3GPP and 3GPP2 are also grappling with the idea of SIM roaming. It is now a possibility that users will be able to keep their existing GSM SIMs and have access to a limited 3G service using a 3G-compatible handset said Engstrom. And with the borders between 2G systems and 3G systems being blurred to this extent, there is also a concern about how what will happen to information sent between terminals that can cope with different data speeds. For instance, what will happen if a videophone user calls a user roaming with their GSM SIM using a basic 3G handset. "There is no good answer yet," said Engstrom.