The main approaches to 4G
In November 2004, Ericsson’s main approach to a 4G successor to HSPA was named within 3GPP: LTE, or Long Term Evolution. As the name implies, the objective was to be attained through evolution and not by reinventing previous technological advances.
The competing CDMA2000 had been developed from its first 3G version into a “turbocharged” form called EV-DO Rev A (Evolution-Data Optimized Revision A). Downlink Rev A can attain a theoretical speed of 3.1 Mbps and an uplink of 1.8 Mbps, if three 1.25 MHz channels are used. The next stage, Rev B, offered a 14.7 Mbps downlink and a 5.4 Mbps uplink.
WiMAX offered yet another alternative. And then, there was China’s choice. China Mobile, the dominant Chinese operator, had been one of the first to opt for GSM and had close links with Ericsson. But the Chinese 3G decision was not what Ericsson and China Mobile had been expecting.
China decided to develop its own 3G standard. This was to enable the largest market in the world to avoid paying license royalties to the major global players and to emphasize its independence. This new 3G alternative was called TD-SCDMA (Time Division-Synchronous Code-Division Multiple Access). It was announced initially that this would be launched by 2005, which turned out, however, to be far too optimistic.
Other wideband alternatives also attracted some attention. These included Flash OFDM, IBURST, Ripwave and UMTS-DD. “There is a whole host of new wireless broadband solutions,” wrote journalist Helen Ahlbom in Ny Teknik in November 2004.
Flash ODFM received particular attention after being chosen by Washington DC in a public procurement process. Flash OFDM was a radio network developed on its own initiative by a new contender, Flarion Technologies. As the name suggests the technology was based on OFDM and offered between 384 kbps and 3 Mbps.
In Sweden, Telia launched WiMAX at the end of 2005 with one base station for the network in every county in Sweden, and in some cases more. The company, like Tele2, was given what was called a Fixed Wireless Access (FWA) license in the 3.5 GHz band. Telia’s network was initially to be used for the operator’s internal transmission requirements.
Author: Svenolof Karlsson & Anders Lugn