Anders Lotsson, Computer Sweden 10/05/2004 11:20:15 http://www.arnnet.com.au/index.php?id=512679146&fp=2&fpid=1 Mobile telephony at 100Mbps from Sydney to Stockholm: that's what the fourth generation (4G) of mobile telephony systems will provide. Eight years from now, 4G phones will be in the shops, according to the vice-president of research at Telefonaktiebolaget LM Ericsson, Ulf Wahlberg. Four years from now, radio frequencies would be assigned, and in 2012 there would be 4G products on the market, he said, at the annual conference of the Swedish Institute of Computer Science in Kista in Stockholm. Wahlberg defined 4G as mobile telephony at a data rate of 100Mbps globally, that is, between any two points in the world. Locally, 1G bps will be possible. "Transmitting a hundred megabits per second between two points at short range is not difficult," he said. "We can do that now. What's hard is to make it work between any two points on the globe." New mobile telephony systems were launched about every 10 years, Wahlberg said. What took time was not just developing the technology: It was necessary to find available radio frequencies for the new systems, preferably the same frequency everywhere. The costs of adapting technology to different local systems were becoming less and less acceptable. "Also, low entry costs are essential," Wahlberg said. A new system should be scalable, allowing operators to introduce a technology gradually instead of making huge investments before they have any customers. What will we do with 100 megabits per second? "We don't know," Wahlberg said. "That's why it's essential to design the network to allow service providers to launch new services and applications easily." The 2008 Olympic Games in Beijing will put so-called combinatory services to the test. Using a 3G telephone, users will be able to follow their favorite athlete continuously on the screen while talking on the same phone to one or more friends anywhere in the world. This will be possible by deploying High Speed Downlink Packet Access (HSDPA) technology, a development of third generation (3G) technology sometimes referred to as 3.5G. That will be a preview of what 4G has to offer. So-called 2.5G technologies, such as General Packet Radio Service (GPRS) and Enhanced Data Rates for GSM Evolution (EDGE), still have potential. EDGE technology, being faster than GPRS, is used a complement to Wi-Fi wireless LAN systems in the US. EDGE is not as fast as the Wi-Fi systems for wireless access, but they work anywhere. You can download your email while driving your car. Yet another acronym to watch for is ABC, which stands for Always Best Connected. This means that the network always knows what carrier systems are available to the user - 3G, Global System for Mobile Communications (GSM), Wi-Fi and, in the future, 4G - and selects the best option. One problem that remains to be solved is the interface between Internet Protocol (IP), and the mobile telephony protocols: "Mobile telephony adds a few milliseconds of latency to give the system time to think, Wahlberg said. "However, IP interprets high latency as an indicator of trouble and reacts by reducing the bit rate. This needs to be solved." |