Forum seeks global standard for 4G data transmission

Trying to untangle the issues for the betterment of the wireless data transmission industry was the goal of the Orthogonal Frequency Division Multiplexing (OFDM) Forum in Calgary, which commenced on July 12.

Global industry leaders met in Cowtown for the two-day event to discuss establishing a single, compatible, global OFDM standard for wireless data transmission. The perceived benefits of the technology would bring a low-complexity solution for efficient communication in environments rife with signal interference.

OFDM is a theoretical modulation technique that can be used in both wired and wireless communication. In a wired environment, OFDM is used as a multi-carrier modulation scheme under the moniker “discrete multi-tone modulation.”

The technology is designed for transferring data at high speeds and low latencies over a distributed IP network. It can support data rates up to 622 megabits per second (Mbps). The OFDM modulator architecture can also be pre-compensated for channel disturbances and alleviate amplitude degradations caused by non-linear transponder characteristics.

“It is a transmission technique which uses multiple antennae and radios at an increased speed, somewhere around five to seven megabits per second,” said Phillip Redman, an analyst for the Gartner Group Inc. in Boston. “It’s still theoretical…AT&T is exploring the use of OFDM for their fourth generation of mobile networks.”

With the conclusion of the OFDM Forum’s second meeting, at which more than 80 representatives from 42 companies came together to debate the issues, the focus now shifts to the tasks at hand: to increase the speed of wireless data/Internet networking and define a universally-accepted standard.

“We’re working towards a global standard,” said Lee Warren, vice-president of business development for Wi-LAN Inc. in Calgary. “To date, there are two standards that are accepted – the IEEE (Institute of Electrical and Electronics Engineers), and ETSI-BRAN (European Telecommunications Standards Institute-Broadband Radio Access Networks). Both are based on OFDM but they’re slightly different from one another.”

Wi-LAN- a principal member of the OFDM Forum and a provider of high-speed wireless data and Internet communications – has tried to beef up the OFDM standard so that it can handle higher bandwidth, has better noise tolerance and added security. The company has patented these changes as W-OFDM.

“We’ve made adjustments and created a very fast, more efficient standard, hence our interest in the Forum,” said Wanda Posehn, Wi-LAN’s vice-president of marketing.

Plenary session highlights during the Forum concluded that user-required data rates are climbing and that the OFDM is the preferred method of achieving higher data rates, particularly in wireless local area network (WLANs) and wireless personal area network (WPAN) standards. The Forum also concluded that OFDM standards, and supporting elements, enhance the cost-effective deployment of fourth generation (4G) mobile networks and that the development of OFDM technology is supported on a global basis.

“Competing vendors are looking at different ways of implementing this technology,” Redman continued. “Without a global standard there’s no economy of scale, equipment differences would be incompatible. It’s a big inhibitor.”

OFDM Forum officials established the Fixed Wireless Access Working Group, which will try to develop a template and outline for standards proposals that can be used by various standards associations around the world. The WLAN, WPAN and Home Multimedia Group focused their sights on supporting and enhancing IEEE 802.11a standards, as well as working with the IEEE, ETSI-BRAN and the Wireless Ethernet Compatibility Alliance.

“The political standards currently established might not necessarily be the best standard and it could cause disagreement within the wireless industry,” Redman said. “Without a global standard, it’s a slow introduction into the market…newer technologies can take advantage of that.”

Other notable principal members of the OFDM Forum include Alcatel, Intersil Corp., Samsung Electro-Mechanics Co. Ltd., Phillips Semiconductors and Nokia Inc.

The next OFDM Forum rendezvous is scheduled for Nov. 2 to 3 in Tampa Bay, Fla.