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Stepping Up To 28 GHz

Grown weary of the interference headaches created by sharing unlicensed 2.4 or 5.8 GHz spectrum with other wireless Internet service providers? We found one WISP that's cured its UNII-band headaches by stepping up to operating in licensed 28 GHz spectrum.

When Quad-Cities Online of Moline, Ill. ran into interference on 5.8 GHz UNII wireless point-to-point backhaul links, the company searched for other solutions. With about 6,000 broadband subscribers and a publishing company behind it, the company had more resources than the average WISP, including an LMDS license for the 28 GHz band that it was not using.

Enter DragonWave, Inc., based in Ottawa, Canada. DragonWave was able to supply Quad-Cities with its AirPair lineup, a wireless solution that provides point-to-point links at 100 Mbps in both directions (full duplex) and operates anywhere in 18 GHz to 36 GHz spectrum. Since 802.11a has a maximum speed of 54 Mbps, this roughly doubles the capacity of the backbone, before allowing for the performance improvements gained through reducing interference.

DragonWave is not the only manufacturer in this area. But Erik Boch, DragonWave CTO, claims that the company's networking and manufacturing expertise put its products over the competition.

"We started with a low cost manufacturing process. While our competitors were hand-tuning their radios in the factory, we figured out a no touch high volume manufacturing process that enabled us to establish partnerships worldwide to sell our product," says Boch. "This was important because, initially, LMDS was not as popular in North America as it was internationally."

"Another advantage," notes Ken Davison, vice president of marketing and sales at DragonWave, "is that we use a conventional surface mount so that the inputs look just like a PBX or router."

"The idea," adds Boch, "is that setup should be really simplejust plug in the RJ-45 Ethernet cable and go."

Of course, there are costs involved with licensed spectrum. Obtaining a license is a process that can cost more than $750,000. At the time licenses were issued, the FCC structured the rules to make it difficult for local cable and telephone companies to acquire LMDS licenses. Officials noted that "given enough market power, [they] could either warehouse the LMDS license to forestall a third party from coming in and competing, or could raise the price of both services they offer." Therefore, the FCC divided the nation into 493 regions, offering licenses within each region.

When LMDS licenses were sold, 38 Mbps was the maximum throughput of most available systems. Although LMDS has always promised gigabit speeds, obtaining those speeds requires a significant chunk of spectrum. Boch noted that DragonWave is "able to get between 3 and 5 bits per Hertz of spectrum, so when a customer has a 50 MHz band, we can reach up to 250 Mbps in total."

The FCC is interested in allowing a secondary market in LMDS licenses to develop, but although the FCC has considered allowing WISPs to trade and lease LMDS licenses in a Notice of Proposed Rulemaking (NPRM), as far as we know, it has not yet actually allowed any trades.

Davison is optimistic. He expects WISPs to deliver an ever larger bundle of services and expects DragonWave to capitalize on WISPs' rising bandwidth needs. He says, "we built our product to run at the high end of the bandwidth curve. WISPs can use it to serve VoIP, video, and mixed data, and our antenna is compatible with a router's QoS and traffic shaping commands."

The AirPair product features:

  • RJ-45 in and out
  • Supports 18 GHz, 23 GHz, 28 GHz, 32 GHz, and 38 GHz
  • Channel widths: 25 MHz, 50 MHz, 28 MHz, and 56 MHz
  • AC powered (DC option)
  • Uses in-based SNMP management, with an 802.1q tagged VLAN option
  • Comes with an optical sighting mount and radio-assisted alignment
  • Designed for outdoor use

The DragonWave radios will be field upgradable when upgrades are available, to speeds of 250 Mbps in both directions or even to gigabit speeds. The company claims its products routinely reach 15 km (over 9 miles) and that free space optic (FSO) competition is good only for short links of less than 1 mile (but FSO manufacturers claim they can reach farther on fog-free days).

This is new technology, so proceed carefully and investigate thoroughly. WISPs should examine the licensed spectrum option because it could enable rural and suburban WISPs to build their own wireless backhauls, significantly saving dollars that would otherwise go to the local telco.

Pricing and availability
DragonWave's AirPair 100 is available now.

For less than $30,000, the company sells one link (a pair of point-to-point radios) with system, antenna, and cable. At 100 Mbps, the product is able to form a part of most networks, especially Ethernet

Reprinted from ISP-Planet.