Will Wi-Fi become a metro service? - Business Networks

Telecommunications Americas, Oct, 2003 by Michael Kennedy

The debate about which technology will win out in telecom access networks, until recently, centered on DSL, HFC (cable modem) and FTTP (fiber to the premises). The answer may be "none of the above," because Wi-Fi could beat them all.

Wi-Fi's potential to become the technology of choice is due to its grass roots origins. Like earlier innovations such as LANs, personal computers and the Internet, those technologies that are simple, easily deployed and require no technical sophistication usually win out over systems solutions requiring top-down implementation like SNA, main frames and ISDN. Wi-Fi's advantages include its use of the simple but versatile Ethernet protocol, use of free unlicensed spectrum, bandwidth up to 54 Mbps, its success as a consumer electronics product--about $60 per user including router and PC cards--and the elimination of wiring with its associated restrictions and cost. Intel, furthermore, seems to have established Wi-Fi as a fundamental part of network computing by bundling it with its processors on its chips.

Wi-Fi, of course, must overcome a number of obstacles to become an effective WAN solution. Its effective range at the maximum data rate is about 100 feet with a practical limit of about 500 feet. It is meant to be a single-node solution; it is not designed to deal with radio networking issues such as co-channel interference, frequency congestion or large numbers of users. It was not intended for mobility applications; no provision is made for handing off users between access points. It does not possess enterprise--let alone carrier-class--security and management features such as authentication, accounting, QoS or roaming control. Finally, like the Internet itself, service billing--not part of the design concept--must be developed.

Efforts not directly related to making Wi-Fi a successful WAN solution may in the end do just that by overcoming all of these obstacles. One set of such efforts is directed toward making Wi-Fi a practical WLAN (wireless LAN) solution for large enterprise sites. They are directed to improving coverage, security, mobility, manageability and scalability. Enterprise networking companies such as Cisco and Extreme Networks and start-ups such as Trapeze Networks are developing enterprise WLAN solutions that extend VLAN (virtual LAN), and authentication, authorization and accounting capabilities well established on Ethernet LANs to Wi-Fi based solutions. The 802.11i and 802.1X standards programs are key to their efforts.

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Others, including start-up AirFlow Networks, are developing technology that transforms simple access points into wireless networks that can cope with radio propagation issues such as mobility, co-channel interference, link-failover and congestion. Another start-up, Tropos, is taking the task of creating a metro Wi-Fi solution head-on by developing outdoor wireless cells that relay Wi-Fi packets throughout the metro area. Proxim Wireless Networks has taken on the propagation distance issue by developing low-cost antennas that will reach up to five miles.

Monetizing (finding a way to charge for service) also is being resolved. A new class of aggregators who supply back-office infrastructure, including Airpath Wireless, Boingo, iPass, GRIC, Pronto and Wayport, have addressed this issue in support of the deployment of hot spot services and wide area enterprise private network solutions. SBC has taken a further step toward making Wi-Fi service pervasive and commercially viable by announcing a goal of deploying 20,000 hot spots by 2006 and making service and billing seamlessly integrated with its 3G wireless offerings.

Within two or three years it seems that enterprise users will never need to plug their laptops into anything other than a power source to recharge their batteries. Most offices, meeting rooms, hotels and public transportation facilities will offer Wi-Fi connectivity. Furthermore, Wi-Fi extensions are likely to be used to provide low-cost Internet access across residential mixed-use neighborhoods, eliminating significant percentages of existing dial-up, DSL and cable modem connections. Wi-Fi, curiously, may accelerate the deployment of all optical solutions, since essentially all of today's 11 Mbps or 54 Mbps Wi-Fi systems are connected to copper-based Ethernet, DSL, cable modem, and T1/E1 transport facilities operating at data rates of no more than a few megabits per second. Pervasive use of Wi-Fi operating at its full 54 Mbps data rate will require a dense mesh of optical backhaul operating at much higher data rates. Consequently, vendors of access network equipment such as BDLC (broadband digital loop carrier) systems, DSLAMs, optical Ethernet and FTTP systems will likely feature Wi-Fi nodes and access points as product feature extensions. The only issue that could derail this bandwagon might be the potential health consequences of holding a microwave transmitter in your lap for most of the day.

Michael Kennedy is co-founder and managing partner of Network Strategy Partners, LLC (NSP)--management consultants to the networking industry. (mkennedy@nspllc.com).