January 2004

Why WirelessMAN?

BY NARESH LAKHANPAL & PHIL ASMUNDSON

Will the new Wireless Metropolitan Area Network (WirelessMAN) standard complement or compete with DSL and cable?

The WirelessMAN standard is causing a stir in technology circles as a potential first- and last-mile broadband connectivity solution. It�s being touted as a wireless alternative to cable modem, T1, and DSL. It could also serve as a backhaul (a system for getting data to a point where it can be distributed over a network) for Wi-Fi hotspots, the access points for public broadband network services designed for wireless users. In a mid-size commercial building, WirelessMAN can support high data-rate connections that might otherwise only be available with a fiber optic line. Those lines, while widely deployed, are notably missing in many metropolitan areas due to the high costs of construction and right of way.

Roger Marks is the chair of IEEE 802.16 Working Group on Broadband Wireless Access Standards, and a physicist with the U.S. Department of Commerce�s National Institute of Standards and Technology. He explains that WirelessMAN is a fixed broadband wireless access standard for the 10 to 66 GHz spectrum with a typical cell radius of between one and three miles �designed specifically to solve the unique problem of the wireless metropolitan area network environment.� An additional standard was added in April 2003 for unlicensed lower frequency ranges of 2 to 11 GHz. Called 802.16a, it has greater range -- typically four to six miles, but up to 30 miles depending on tower height, transmission gain and power transmit -- and can �see� through buildings and trees. �WirelessMAN is a standard that the industry can use to really drive prices down, raise performance levels and reduce uncertainty,� says Andy Fuertes, a senior analyst with Visant Strategies.

Competitor or Complement?
Whether WirelessMAN competes with cable and DSL depends on where it�s deployed and what else is available, says Marks. �If someone wants broadband access and can get cable or DSL, it would compete as another alternative. From a network operator�s point of view, it could give them a way to get to the consumer. But there are plenty of places where there isn�t an economical means of getting suitable wire to the customer. Operators generally go for high-density populations, not business districts. So there�s an opportunity for wireless systems to provide service where there isn�t any other economically feasible way. You don�t need density to make 802.16 economical.�

Daryl Schoolar, senior analyst of advanced carrier systems for In-Stat/MDR, notes that the big advantage of WirelessMAN is that it�s cheaper to deploy than wired systems. �You rarely see one technology totally supplanting another,� he says. �They tend to co-exist. It will be hard to compete against installed cable modems and I don�t see the phone companies ripping out their installed DSL base. They�re more likely to use WirelessMAN to add services where they haven�t already installed or couldn�t install for financial reasons.�

WirelessMAN could be a cost-savings alternative for wireless carriers. If you�re a wireless carrier, you could avoid using that wired network and use WirelessMAN, which should bring your costs down. Building the Wi-Fi network is another potential use for WirelessMAN, say experts. A new Allied Business Intelligence study tallies the number of public wireless computer networks at 28,000 currently, but forecasts that will surpass 200,000 in five years. WirelessMAN could provide the backhaul connectivity needed for those hotspots in convention centers, hotels and other public places.

Margaret LaBrecque, president of the Worldwide Interoperability for Microwave Access (WiMAX), the nonprofit group formed to certify and promote the standard, lays out a scenario: �You could be at a conference at a hotel today and have a meltdown because 600 people want to use a hotspot at once with only a single T1 line supporting it. Because of the infrastructure today, you have to increase the bandwidth with wire, and for only five days, that�s hard and expensive.� LaBrecque, who is also the marketing manager of Intel�s Broadband Wireless Access Initiative, adds, �With wireless, it could be done almost immediately and then removed. That�s where the quality of service of 802.16 comes in. You can allocate bandwidth on a connection-by-connection basis on-the-fly.�

Other major benefits to WirelessMAN are security and quality of service. �Wireless may have a bad name on security because the 802.11 [a standard for providing wireless capability to local area networks] group didn�t do it carefully,� says Marks. �They made some mistakes. When we did 802.16, we knew we were doing it to serve corporate purposes in an outdoor environment where there would be an incentive for people to attempt breaches. So we borrowed heavily from an existing security protocol called DOCSIS, which is used in cable modems and requires heavy authentication.�

As for quality of service, Marks notes that the Medium Access Control (MAC) layer system is carrier class. This is important because the MAC protocol coordinates access to a channel so that information can be transmitted from a source to a destination in a broadcast network. It can support sophisticated services, controlling the airwaves through a scheduler that grants bandwidth on demand to users when they need it. �It�s a version of time domain multiple access, which is how most cell phones work,� he explains. �This allows for differentiated quality of service; it�s probably the only wireless standard that can support this. And, it can support different levels of service, including just best effort.�

That means that an operator can provision bandwidth to charge different fees for different levels of service, from real-time video conferencing, which requires strict limits on time of delivery, to streaming audio or video, which needs continuous streaming.

Quality of service and security are critical. If they can prove they�re a secure and stable network, solve the economic issues for last mile, and show that deployment costs are much less expensive compared to cable and DSL, it�s a viable product.

The Birth of WiMAX
It�s one thing to have new and cool technology; it�s another to get it out in the world in a meaningful and profitable way. That�s where the WiMAX organization comes in. WiMAX includes some heavy hitters, such as Intel, Nokia and Fujitsu Microelectronics America.

�There are some companies that have their own solutions now, but they�re proprietary,� explains LaBrecque. �They may comply with the 802.16 specifications, but they�re pre-standard. Our job is to set up a certification lab. We want to drive interoperability and encourage equipment makers to produce products.�

During the next year, WiMAX will develop conformance test plans, select certification labs and host interoperability events for 802.16 equipment vendors, and work with the European Telecommunications Standards Institute to develop test plans for HIPERMAN, Europe�s broadband wireless metropolitan area access standard. Ultimately, those products that successfully complete interoperability testing will be labeled �WiMAX certified.� LaBrecque expects to see WiMAX-certified equipment from certified vendors by the end of 2004. �By the beginning of 2004, we�ll have tools vendors can use to test the equipment so that when they go to the lab, it�s a slam dunk. Then they can participate in the interoperability events.�

Interoperability will get a boost when another amendment to the standard is introduced: 802.16e, with nomadic functions. LeBrecque expects the amendment to be done this year. �When you introduce nomadic capabilities that allow users -- who may be using different types of equipment -- to roam from one operator�s service area to another, interoperability is mission critical,� she says.
It might also make the game interesting to telecom carriers. If they can get it to a mobile environment, you�ll have inexpensive voice over IP. So, WirelessMAN does potentially pose a challenge to both wireless and wireline carriers.

Naresh Lakhanpal is National Director of Products and Services, and Phil Asmundson is Deputy Managing Partner for Deloitte & Touche�s Technology, Media, & Telecommunications (TMT) Group. The Technology, Media & Telecommunications (TMT) Group has deep industry knowledge of technology, media, and telecommunications companies and the challenges these industries face in areas such as Internet, software, computers, telecommunications and networking, semiconductor and related industries, along with broadcasting and publishing. TMT has a global network of dedicated professionals who can deliver innovative solutions to clients wherever they are in the world.

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