Sidecut Reports

(Editor’s note: The following is an excerpt from our latest report, Inside Clearwire: A Network Report, which looks specifically at Clearwire’s use of open core networking standards for its nascent national WiMAX broadband network. The full report can be downloaded FREE by clicking on this link.)

OPEN IN THE CORE MEANS COMPETITION AND SAVINGS

If you follow the cables down from the antennas on a typical “3G” cellular tower, they almost always end up leading into a building the size of a largish tool shed or a small garage — typically a 10-foot by 12-foot (or larger) enclosure that houses all the complex gear necessary to process, separate, administer and manage the phone companies’ mix of voice calls and data traffic.

Since Clearwire is building a data-only network, its tower-site infrastructure needs are much simpler than cellular. To house a typical Clearwire tower site’s power needs, microwave backhaul, WiMAX antenna gear and an Ethernet switch takes merely an enclosure the size of a large refrigerator, sitting on a 3-foot-by-5-foot space.

With far less gear than a comparable cellular site, Clearwire chief techincal officer John Saw said his network is not only obviously cheaper to operate but also more flexible, allowing for quicker and closer deployment toward its customer base.

According to both Saw and Barry West, Clearwire’s president of International operations (and the former head of WiMAX operations at Sprint Nextel before its merger with Clearwire), a typical WiMAX network is about eight to 10 times cheaper to build than a 3G cellular network covering the same area.

“Our average cost number per cell site, when you add in all the backhaul access, zoning costs and everything else, is less than $150,000 per site — and the real number is actually much lower than that,” Saw said. “You’ll never get a cell site at that cost for 3G. What we have done on the network side is the lowest cost approach we could get to.”

Inside its network, Clearwire also embraces an openness that will allow it to reduce costs by introducing a competitiveness not typically found in cellular networks. In the latest implementation of the WiMAX standard, there is a model that calls for true open interfaces between infrastructure gear, like base stations, radios, and administrative equipment like the Access Service Network (ASN) gateway, the workhorse box of a WiMAX network that aggregates and distributes a wide range of subscriber-related data, from session management information, billing data, traffic and mobility management, quality of service and other administrative functions.

In cellular 2G or 3G data implementations, Clearwire’s Saw said that a single vendor almost always provided all the different pieces of gear needed, often at a premium cost. “What we wanted to do with Clearwire was break the monopoly between the base station provider and the gateway provider,” Saw said.

To win a contract for Clearwire’s new IP-based network, however, means that vendors must comply with the open interfaces requirements. Bruce Brda, senior vice president and general manager of the wireless networks business at Motorola, said that opening up such internal interfaces inside a cellular network allows Clearwire to act as its own system integrator, which could produce cost savings and spur product innovation.

“These interfaces have never been open before — now the carriers like Clearwire have the ability to mix and match,” Motorola’s Brda said. “It’s great to have a clean slate, and to have the flexibility to pick the best vendors for the best elements. The downside is control, in how you manage and debug a disparate network. That’s a challenge.”

But Kittur Nagesh, director of service provider marketing at Cisco, said the positives outweigh the negatives when it comes to combining gear from different vendors.

“In some sense you can say Clearwire is now able to pick the best of breed to meet their specific needs,” Nagesh said. “Right now they have transport and Layer 4 to 7 gear from Cisco, and ASN gateways from WiChorus. When it’s done right you can actually combine the best of breed from multiple companies.”

For more on Clearwire’s network, download our latest report, Inside Clearwire: A Network Report, for free by clicking here.