Computeruser.com
Latest News

Wireless networks come of age

Wireless broadband may be a year away, but wireless LANs are here to stay.

When traveling executives of Countrywide Home Loans Inc., the largest independently owned bank in the United States, return to their offices, they don’t plug their laptop computers into the corporate network to upload or download data. They simply turn them on for an instant connection to the company’s wireless network (WLAN). In meeting rooms they can access documents and reports for presentations, or log on to the Internet to check for new government regulations affecting financial services industries.

An early adopter of wireless technology, Countrywide launched its first WLAN initiative in spring 2000, in 13 core facilities in California and five core facilities in Texas, resulting in 300 highly mobile executives, says Lorraine Van Berkel, Countrywide’s Internetworking engineer. “We wanted to simplify their network connections as they moved about, and give them flexibility,” she explains. “It was considerably cheaper than buying each executive a networked desktop PC, since they already had laptops.”

Countrywide deployed Proxim’s Harmony, an enterprise-class 2MB 802.11 WLAN product line. Although a proprietary solution at the time, it was chosen because it had the extra security a mortgage banker needed. To that, the IT department added VPN software to nail shut any possible security holes. Countrywide also purchased Proxim’s Controller to manage all the WLANs from a central location.

Though Countrywide was one of the first to deploy a WLAN, it is by no means the last. Thousands of offices around the country have taken to the technology. And while early adopters typically came from larger companies, small and medium-sized companies also are discovering the benefits of the technology. According to Gemma Paulo, research analyst for networking at Scottsdale, Ariz.-based Cahners In-Stat Group, “3.5 million wireless hardware units–Access Points and PCI/PCMCIA adapters–were shipped in 2000. In 2001, the industry shipped 8.1 million units. We’re being conservative in predicting 10.9 million units for 2002.”

There always are issues with any IT deployment, but installing the WLAN is far less complicated than building a wired network. Van Berkel could not pinpoint the cost of the 18 wireless networks because some of the hardware was upgraded to the newer 802.11b standard about a year ago, which boosted system throughput to 11MB, the equivalent of a 10-BaseT-wired Ethernet network. “We take advantage of Proxim’s upgrade plan, so we benefit by acquiring new wireless technology at a lower cost,” Van Berkel says.

Out of the past

Wireless networking is not a recent phenomenon. It got its start more than a dozen years ago with portable bar code scanning devices manufactured by companies like Symbol Technologies Inc. of Bohemia, N.Y. The devices quickly became popular in warehouses and retailing chains like Kmart and WalMart, which could take inventory and place orders on the store floor and send that data to a local server, which in turn relayed it over satellite networks to corporate offices across the United States. That eliminated the time-consuming process of filling out forms by hand and then keying the data into a computer.

By the mid-1990s, a variety of proprietary WLAN solutions sprouted around the FCC’s unlicensed 2.4GHz band. Early adopters included healthcare facilities, school districts, universities, and office campuses, where drilling holes and laying cables was very expensive or posed possible asbestos concerns.

One key incentive offered by wireless technology was its ability to link multiple buildings in a radius of several miles through inexpensive microwave antennas. That made wireless an affordable solution for networking school districts. Companies also deployed solutions from vendors like Solectek, to bridge networks in campus facilities where buildings were separated by rivers or highways, rather than continue spending $5,000 per month or more for each leased line. If there’s a clear line of sight, Solectek’s technology can link buildings more than 20 miles apart. Even though WLAN equipment was more expensive several years ago, the ROI of an implementation was usually achieved in only four to seven months.

Conquering the digital divide

Wireless networks are moving rapidly into large and small municipalities across the country. One of the more interesting wireless applications is now operational in Allegany County, Md. Located 150 miles west of Baltimore, the county had no affordable access to leased lines to link schools, libraries, nonprofits, and government buildings. Leasing costs for a single DS3 and an OC3 line for Internet service is $28,000 a month, according to Jeff Blank, supervisor of networking and microcomputing for Allconet, the county’s municipal network. “We were in a rural region classified as the ‘Digital Divide,'” says Blank. “High-tech and other businesses looking to relocate here were going to northern Virginia and Pennsylvania because the cost of a DS3 is only $7,500 to $8,500, and low-cost Internet connectivity is available from numerous ISPs.”

Four years ago, Blank and several IT associates proposed building a wireless network. Three years later, at a cost of $300,000, Allconet has 95 buildings, 4,000 workstations, and 10,000 people using BreezeACCESS 802.11b hardware from Alvarion Inc. Internet access comes through the SAILOR state network–Maryland’s state library system. Armed now with a $2.9 million federal grant, Allegany County has begun work on Allconet2.

“We’re rebuilding the entire network from the ground up,” says Blank, “to improve our coverage area, our speed, and our redundancy.” When completed, the network will be running on a licensed microwave backbone around the county, with 16 towers and a DEC3 SONNET Ring, the term for wireless fiber.

That will provide a core backbone with 311MB throughput, and it will enable the county to provide a telecommunications infrastructure to 85 percent of its residents, 95 percent of its businesses, and 100 percent of its industrial parks. And by consolidating all Internet traffic around the county into one pipe, the county government can negotiate better rates on DS3 lines for itself and ISPs, and offer relocating businesses affordable telecommunications to the outside world.

The standards game

When WLAN industry players got together with the IEEE several years ago and hammered out wireless standards on which equipment makers, software developers, semiconductor firms and encryption vendors could build, the 802.11b specification became universal. And for the first time WLAN equipment became interoperable; that is, you could buy the required components–Access Points (ACs), wireless gateways, routers, hubs, PCI cards, and PCMCIA adapter cards–from multiple vendors and have them work together.

To insure interoperability, the industry founded the Wireless Ethernet Compatibility Alliance (WECA) to independently test and certify WLAN hardware and software. Although compatibility testing is still in progress, 60 of the more than 140 WECA members are marketing certified products, according to the alliance’s Web site.

With competition so fierce, the cost of 802.11b consumer and small business wireless products from Proxim, SMC, RadioLAN, Linksys, NetGear, Intel, and others has dipped to commodity pricing levels at discount electronics chains like Best Buy, Circuit City, and CompUSA. Prices are likely to erode even further when products following the faster and more robust 802.11a standard begin volume shipments, as enterprise organizations begin deploying high-speed WLANs.

A December 2000 Campus Convergence study released by Stamford, Conn.-based META Group reveals that 72 percent of corporations said they were planning to implement a WLAN. Peter Firstbrook, META’s senior research analyst for networking, stated that 29 percent of reporting companies had already deployed WLANs, 20 percent planned to in the next 12 months, and 24 percent planned to in the next 24 months. Only 27 percent had no plans for wireless.

While small companies with 10 to 100 employees are likely to consider an all-wireless network, larger, enterprise-sized organizations will look to deploy it strategically for meeting rooms and mobile employees, and in facilities where it is a more convenient solution than a wired network. Yet, there are concerns.

Wi-Fi’s security woes

Although WECA’s RC4 40-bit and 128-bit encryption standard ships with all WLAN (or Wi-Fi) systems for interoperability purposes, not all users and vendors are convinced that it addresses high-end security needs.

Most industry experts concur that the standards groups did a fairly decent job. However, Patrick Leary, chief evangelist for Alvarion Inc., says, “Like other emerging technology, wireless networks are being used in applications that they were never really intended for in the early stages. A lot of the security holes are due to the manufacturers themselves, who have allowed their radios to operate in promiscuous mode–where clients actively look and poll for an Access Point.”

It used to be that IT had to set certain parameters within the client itself. But now, to make it easy to install a WLAN, interface cards have auto-client characteristics that allow them to latch on to Access Points. “It’s those abilities, which weren’t anticipated by the standards, that cause problems,” Leary says.

META Group’s Firstbrook agrees. “Wi-Fi was supposed to provide security interoperability, and it has failed,” he says. “Now all the vendors are layering on their proprietary security, which means that interoperability between vendors is becoming problematic. When you choose a vendor, you’re pretty much married to him for the duration of your implementation.”

That has made WLANs incredibly vulnerable to outside snoopers. With a laptop, a wireless interface card, and the right software, a hacker parked near a WLAN installation can crack current encryption technology within 15 minutes, says Jerry Wang, CEO of Bellevue, Wash.-based NextComm. The firm has developed application-specific integrated circuit (ASIC) technology for 802.11-compliant systems that deploys the same kind of secure key-hopping used in credit-card authentication technology.

“Most encryption software changes authentication keys between user and Access Points every time the user logs on,” says Wang. “With many connections lasting more than 15 minutes, a hacker has ample time to do his dirty work. Our NC7010 Media Access Controller (MAC) chip transparently changes the keys every three seconds.”

“Until the IEEE completes the updates for the 802.11a security protocols, we still recommend VPNs to customers,” says Scott McLaughlin, a Hillsboro, Ore.-based spokesperson for Intel’s wireless products.

No conversion rush

802.11a offers five times the bandwidth of 802.11b and superior performance characteristics, but the propagation characteristics of the 5GHz spectrum has a smaller wavelength than the 2.4GHz band, and its ability to penetrate obstacles is fairly poor. “Even its ability to go through a couple of dry walls is nowhere near what 2.4 can do,” says Alvarion’s Leary.

“We’re testing the newly released 802.11a technology,” says Countrywide’s Van Berkel, “and we’ll deploy it strategically for users who require higher bandwidth.”

Analysts are waiting to see how quickly users adopt 802.11a. Paulo of Cahners In-Stat Group says, “We haven’t seen any wireless 802.11a products from 3COM, Cisco, Agere, or Terrasys. They’re very trusted in the enterprise space. 3COM and Cisco are likely to set the trend–but we’ll have to wait and see whether they broaden their 802.11b lines and what they will deliver in terms of .11a products.”

Numerous hybrid products containing the 2.4GHz and 5GHz spectrums on Access Points and PC Interface cards are on the verge of release, making wireless networking a technology to be reckoned with.

Leave a comment

seks shop - izolasyon
basic theory test book basic theory test