Lucent has a Blast: Technology may enter smart antenna market space

Lucent Technologies' experimental Bell Labs Layered Space-Time technology is after the same capacity-saving goal as smart antenna technology-a concept that has been under development for almost a decade.

Lucent recently uncovered Blast, calling it a breakthrough technology that could increase wireless system capacity by 20 to 40 times, said Reinaldo Valenzuela, head of Bell Labs' wireless communications research department and the Blast research team. "It's a new technology that opens the bottleneck that until now we've been wrestling with," he said.

The concept behind Blast exploits the interference that occurs when transmitting more than one signal in a frequency. "We are multiplying capacity by purposefully creating interference," Valenzuela said.

Using Blast, transmissions are sent and received by multiple antennas in a single frequency band. Signal processing separates the mutually interfering transmissions to identify and recover the transmissions. Blast essentially adds a spatial dimension to the frequency and time dimensions usually used in wireless transmissions.

Valenzuela compared the concept with a scenario in which multiple people in one corner of a crowded room try to discern what a person in another corner is saying. If all the people record what the speaker says and compare recordings-made from slightly different distances and angles-they can piece together what has been said. Blast, though, sends multiple transmissions simultaneously, as if the group were actually trying to listen in on multiple conversations at the same time from the other side of the room.

"In theory, you can keep adding antennas, and the capacity goes up," Valenzuela said. Lucent's lab experiments of Blast used eight transmit and 12 receive antennas.

Blast's capacity-increasing capabilities make it comparable with smart antenna's, but it has some distinct differences, said Peter Carson, vice president of business development for ArrayCom. "It endorses ArrayCom's business strategy," he said. ArrayCom, which has been dedicated to developing smart antenna technology for seven years, currently achieves 20-fold improvements on its commercial local loop systems, he said.

ArrayCom's products use multiple transmit and receive antennas at the base station, so they can be used for mobile applications. Smart antennas are also adaptive, Carson said.

A good fit for Blast technology would be wireless local loop systems, where size of end user equipment is not an issue, Valenzuela said. A mobile handset, for example, might pose problems, but laptops could be ideal for high-capacity data requirements, he said. However, Valenzuela emphasized that Lucent must do more research before it can identify systems that might best fit the technology and determine if real products are even possible.

While Blast could help increase the market for products such as smart antennas, Carson warned that the transition from the lab to the market can be long and arduous. But by the time Blast manifested itself in a real product, it might be just about when carriers need such capacity-boosting products.

Smart antennas have been used in capacity-constrained areas, but carriers using most other technologies don't have the need yet, said Ira Brodsky, president of Datacomm Research. But in the future, if wireless begins to significantly displace wireline traffic, carriers may turn to capacity-enhancing products to accommodate more traffic, he said.

The possibility of a commercial product will depend on Lucent's ability to price it right and decrease the antennas' size, said Bukasa Tshilombo, senior analyst at Dataquest.