Clearwire picks Raze for first licensed trials

Clearwire Technologies (www.clearwire.com), after amassing Instructional Television Fixed Service (ITFS) licenses (2.5GHz) covering 100 U.S. markets, is being courted by a number of second-generation wireless-broadband equipment vendors. So far, Raze Technologies (www.razetechnologies.com) is getting the first dance.

Bryan Olivier, Clearwire vice president of network engineering and development, said the carrier, after hearing from 14 vendors, is likely to trial three to four eventually, in hopes of narrowing those to one, or perhaps two, for market trials.

Clearwire is a company that has changed direction in recent months. Founded as a manufacturing company, it developed a first-generation, fixed-wireless product that has been deployed in 11 markets including four Clearwire markets. However after announcing a deal for spectrum with the ITFS Alliance this past March, the company refocused on services.

Clearwire Holdings owns the two separate entities, equipment company and service provider, which operate “at arm’s length,” according to Olivier.

Its early deployments are all in the unlicensed ISM bands, and Clearwire looks forward to the advantages of licensed spectrum. In the ISM bands, interference is difficult to overcome because of power limits and height issues with base stations, Olivier said. With licensed spectrum, you can transmit at higher power, are better protected from interference and can better manage the cell radius.

Clearwire believes the benefits of second-generation equipment will include higher density per tower, speeds up to T1 and above, and better penetration.

“The goal for any service provider is to approach self-installation,” Olivier said. “To get there, you have to have a product that is more non-line-of-sight (NLOS).”

He believes all the vendors today use the term NLOS rather loosely.

“I don’t think any of the vendors has a strong NLOS product,” Olivier said. “I think they’re approaching it.” Standardization should help.

Once the 802.16 standard for fixed-wireless is complete, the industry can move away from programmable logic in the radios to ASIC (application-specific integrated circuits), he said. This should drop the costs of both base stations and customer-premises equipment (CPE), as CPE can be interchangeable among vendors. Most vendors are trying to follow the standards development with their equipment as much as possible, Olivier said.

That’s certainly the case with Raze, according to Paul Struhsaker, Raze CTO, who was one of the founding members of the 802.16 standards group.

“Whichever way 802.16 ends up going, we can use our techniques,” he said.

Raze uses a military technology called block-frequency domain equalization. OFDM is not part of its technology although its technique, which is modulation independent, can be used with OFDM.

Raze’s NLOS technology is achieved by several elements:

• Advanced signal processing in order to use the multipath, rather than fight with it.

• Multiple receivers or MIMO technology.

• Advanced ARQ (automatic request for repeat): “We take big long packets for TCPIP, divide them into fragments, and if any of the fragments has an error in it, it is quickly retransmitted so the upper levels of the protocol stack never sees the errors,” Struhsaker said. “We can operate on poor links and have the appearance of fantastic signal quality.”

• Adaptive modulation and adaptive forward-error correction: “If the link is bad, we keep switching down until we get a good-enough-quality link so that those packet-error rates and retransmissions from ARQ hit an acceptable level.”

Another key to the Raze technology is software-defined radios. When you don’t have a well-defined standard in place, you want to be software-defined so you can move where the standard goes, Struhsaker said.

Raze’s standard product is two voice lines along with data, although carriers can turn on either function with the click of a key.

Clearwire is most interested in the data capability, although it is considering several value-added service overlays, and voice is one of them, Olivier said.

Raze has a trial with North Texas Web Services (www.ntws.net) in the unlicensed U-NII bands and looks forward to its trial with Clearwire in the licensed ITFS/MMDS bands. It also is eying Latin America where it could reuse its 2.5GHz products.

“We’re very focused on the independent telco market, the utility market and also the regional ISP market where we’ve seen a lot of demand for regional dial shops that want to upgrade their subscriber base to broadband,” said Nick Thomas, Raze senior vice president of sales and marketing. The independent-telco community is as strong as any RBOC — about 1,000 companies with 21 million access lines between them, he said. These telcos haven’t rolled out much DSL because they’re in lower-tier markets where the loops are a lot longer than in tier 1 markets and the quality of the copper is poor, Thomas said. Like most MMDS vendors out there, Raze also wouldn’t mind getting some business from Sprint (www.sprintbroadband.com) or WorldCom (www.worldcom.com).

John Festa, Raze president & CEO, said what they’re really looking for are MLECS —LECS with money.

“One company that is absolutely an MLEC is Clearwire,” Festa said, describing the carrier as very aggressive and well funded, with a management team that understands the business.

“Clearwire is not out there looking for science projects, and we’re not a science project,” he said.