Beyond 2.5G and 3G Wireless Networks Flarion's Flash-OFDM

Radio Router Technology - Flash OFDM (Orthogonal Frequency-Division Multiplexing)

While CDMA and UMTS increase the capacity and spectral efficiency viewpoints as compared to 2G and 2.5G wireless networks, there are still issues with these packet networks when applied to wireless data. Scientists are working on improving upon the spectral efficiency of CDMA. Another inherent problem with wireless data transactions is that information is not always sent in high-speed bursts bi-directionally. Unlike packetised voice, there is a constant protocol and conversational chit chat between the sending and receiving software. There is an inherent latency and propagation delay between the two end points.

Flarion's Flash-OFDM network technology tries to address the needs of wireless data in an innovative way. According to the vendor, Flarion system is the first truly IP-based broadband cellular network designed for data, and it outperforms 3G in all critical areas of performance. For example, the system is capable of sustaining 12 Mbps of throughput per cell in a 3 carrier, 3-sector configuration, peak user data rates up to 3 Mbps, full cellular mobility, les than 20 milliseconds of latency, and full QoS. Flarion claims to have successfully developed, tested and carried out technical trials of the system in 2001, and is planning to demonstrate in NY a market trial system. 

Radio-router technology uses a radio-transmission framework for packet- based, broadband, IP wireless communications. Radio-router technology is designed to make links in an IP network mobile. Proponents of Flash-OFDM hope that since IP network technology is already well developed and inexpensive, radio-router systems will be relatively easy, quick, and economical to implement.

A radio-router network can be built atop the existing IP infrastructure, rather than from the ground up like a 3G network, said Rajiv Laroia, founder and chief technology officer of Flarion Technologies, which develops radio-router-network equipment.

The technology uses OFDM, in which a single channel is divided into several subchannels, each at a different frequency. This boosts bandwidth by letting a system carry several transmissions at the same time. Radio-router systems offer a maximum throughput of 1.5 Mbits per second, about the same as a T1 line. OFDM, unlike traditional FDM, uses signal modulation and demodulation techniques, as well as the orthogonal placement of adjacent channels, to minimize interference. There is less emphasis on individual channels' quality.

"Radio router is a data-focused technology, designed from a data perspective. But it does support voice- packet-switched voice, not circuit-switched voice," according to Flarion. 

Radio routers, IP routers with radio adjuncts, would handle packet traffic and serve as the equivalent of cellular base stations. Consumers would connect with Flash-OFDM networks via PC cards in their notebooks and via flash-memory cards in handheld devices. .

Caution - An uphill battle with the established cellular networks 

Despite the technology's potential, AT&T's Henry says, "Radio routers face an uphill fight against the entrenched cellular businesses." Cellular providers are much bigger and better established companies, he explained, and cellular service appears like a safer investment to many managers. Radio-router technology, on the other hand, might seem exotic and thus might not attract big infrastructure investments, he said.

Other caution is that Flarion's air-link interface introduces yet another standard and it will face usual battles and delays in getting components built to match Flarion's reference designs.

For More Information - Go to Flarion's website