NEW YORK-If smart antennas are so intelligent, why are they not yet widely deployed in wireless networks?
The concise answer is their comparatively high price, but that shorthand omits the more complex context of a complete answer, said Lee Hamilton, president and chief executive officer of AirNet Communications Corp., Melbourne, Fla.
Given that wireless customers are becoming increasingly mobile with their mobiles, network infrastructure needs to pick up and send communications from growing numbers of locations. Instead of waiting for customers to wander into range, smart antennas are designed to find and follow them as they talk and listen to their handsets.
It seems like a great idea, but the evolutionary step now commercially available has inherent limitations, and the next generation of smart antennas is still a gleam in an inventor’s eye, Hamilton said.
The current generation of smart antennas uses “switched beams,” which are fixed in place but turn on when they pick up a wireless customer talking on the phone.
“The next big leap is `adaptive beam’ antennas, a better idea that focuses the energy like a flashlight beam that follows where you talk,” Hamilton said.
Ironically, this idea to improve wireless communications is based on signal-jamming technology the American military developed in the 1970s. However, no adaptation is available yet for civilian carriers, he said.
“Adaptive beam technology can double or triple capacity so you can use more frequencies at each cell site,” Hamilton said.
“We have gone to one of the military [contractors] that has this technology and asked them to develop a (programming) card that slides into our base stations.”
AirNet, which went public in December, designs and builds base stations using broadband, software defined radios for Global System for Mobile communications networks. It has received 34 U.S. patents for its technology and has an equal number of patent applications filed, Hamilton said.
Traditional base stations are protocol specific, so each one can only handle just one kind of wireless technology, whether GSM, Enhanced Data Rates for Global Evolution, General Packet Radio Service or third-generation mobile communications.
Software defined radios use computer software to upgrade base stations by adding capabilities to work with new standards and by allocating bandwidth, as demand requires, among standards, Hamilton said. Likewise, a software addition could handle the functions of switched beam and adaptive beam antennas.
In its request for comments on software defined radios, the Federal Communications Commission issued this statement March 21: “Software defined radios could offer tremendous advantages to consumers over currently available wireless equipment … [including] lower cost, a greater variety of features and the ability to adapt to multiple communications standards.
“They could also offer advantages to manufacturers, [like] increased economies of scale in production, increased worldwide market opportunities and a decrease in the number of devices that must be maintained in inventory.
“Software defined radios could expand access to broadband communications for all persons and increase competition among telecommunications services providers.”
