Wireless for Contractors

Think of installing wireless systems as 7-Up for the electrical contractor. 7-Up is the un-cola, a caffeine-free drink that doesn't get you wired. Wireless systems are un-cabled, so they don't get you wired, either. For its entire business life, the typical electrical contracting firm has built a reputation on wiring buildings. Wire strippers, cable pulls, and connectorizing are part of the everyday job. Then, along comes wireless. "We always stress that wireless is different - it is nondiscriminant and you can't guarantee reception," said Robin Jellum, marketing engineer with 3Com's Wireless Connectivity Division. In most cases, contractors complete wireless LAN (local area network) installations without a hitch. But when things do not go right, finding a solution can be tough. "There is significantly less effort or work required to ready a wireless LAN relative to running a wired LAN," according to Ron Seide, director of product marketing with Aironet Wireless Communications, Inc. (Aironet is being acquired by Cisco and will be their wireless arm) based in Akron, Ohio. "In a typical home or small office, you are talking about locating only one or two access points," he continues. If current projections hold true, there will be many such small office and home installations over the next several years. Wireless will be big business for the contractor who is prepared. The MultiMedia Telecommunications Association (MMTA), Arlington, Va., predicts that, from 1999 through 2002, a total of $14.6 billion will be spent on both the cellular and PCS infrastructures. More will be spent on cellular than on PCS, mainly because the cellular infrastructure has a much larger footprint. Total U.S. spending on wireless is projected to jump to $81.8 billion by 2002, an increase of 13 percent, compounded annually. Helping customers In-building wireless will be quite popular in offices with fewer than 100 employees, says Jeff Orr, home networking products manager for Proxim, Inc., Sunnyvale, Calif. "If the office moves and your contractor has run wire, you lose that investment. With wireless, you own the equipment and can take it with you," he said. The contractor does not lose money, however, since he'll likely be called back to reconfigure the wireless system each time it is moved. While Orr maintains that there are strict differences between home and commercial systems, he says the benefits are similar. There is no dragging of copper or coaxial cable. "A retrofit requires a person who can minimize destruction of the existing building," he continues. "Using wireless lets contractors get into a new market and makes the job easier for them since it eliminates limitations they may have with traditional hardware." Amir Zoufonoun, president and general manager of Western Multiplex, Belmont, Calif., says the market is realizing that wireless provides an excellent alternative to costly, high-maintenance leased lines. His firm provides network infrastructure equipment, including IP-based Ethernet and Fast Ethernet wireless bridges, T-1/E-1 and fractional spread spectrum license-free wireless systems, and licensed digital microwave links. Leased-line DS-3 service typically requires between 90 and180 days for installation and can cost between $10,000 and $15,000 per month. A fixed-wireless transmission system, including a license-free wireless link operating at DS-3, can be installed for less than $30,000 per link. A product like their Lynx is available immediately and DS-3 service can be operational with no recurring costs in less than a week. Fixed wireless technology enables high-bandwidth applications to take place between fixed locations, such as office campuses or between a customer site and an Internet service provider, thus bypassing the telephone company. The wireless system replaces copper or fiber for connections to the telephone network, and reaches places where wire and cable are poor or expensive options. Do a site survey Jellum says the most important task when installing a wireless network is to do a site survey. His company provides a tool with its access point product - an application that can be installed on any laptop - which will help determine reception. "Be sure the laptop has good battery life … you'll be doing it for a while," he says. He strongly cautions against letting the ease of most installations lull a contractor into skipping the site survey. An elevator shaft, a kitchen with a lot of metal, thick concrete walls, steel studs, and even large metal fans can wreak havoc with a wireless installation. In a medical building, there will be rooms that are leaded, like the x-ray room, where no radio can penetrate. "Look at the blueprint," Seide says. "In the majority of cases, what you see will be borne out in the actual installation." "Basically, you are setting up a cellular network," Jellum says. "If you're only doing a single conference room, it is simple. For complete building coverage, you need to provide some overlap." Aironet also provides site survey software. "The key is centering the access points for maximum coverage," Seide says. A thorough site survey for an office is likely to require about an afternoon's worth of work. Their Link Scope program graphically displays the quality and strength of the signal. There are three typical interfaces between the hardwire and the wireless network: cable modem, DSL and simple dial-up. For cable modems, the jack should be placed in the center of the facility. DSL and dial-up are apt to be somewhat simpler, since the interface can be to any RJ-11 telephone jack, and the jack can be installed wherever telephone wires run. Jellum says the best way to view any wireless LAN, including their own AirConnect, is as an extension of the wired LAN. It's the same bird with different feathers. However, the access points for the wireless segments rarely fall next to a power outlet. To make the job easier, they include a Power Base-T module with their kits. All that is required to bring both power and the data link to the Power Base-T is a single Cat 5 cable. It provides both the data connectivity and the power for the system. Pulling data cable typically is cheaper and easier than pulling power - and pulling one data cable certainly is easier than pulling both data and power. The standard for a typical 11 Mb/s system is 802.11b and it dictates the radius of coverage. Be familiar with it and its related standards. John Keplinger, radio frequency (RF) systems engineer with Telemetry Technologies, Inc. (TTI), Rosenberg, Texas, says that many firms buy radios and try to plug them in, only to find out that they don't play. "The thing they don't do is get properly trained." TTI, which bills itself as a "full-service, wireless systems house" has been working with wireless since 1984. "There is a certain degree of training that has to take place before you can successfully install any RF," Keplinger said. He recommends that installers get some practical applications training before heading to the field. "When you venture into a new area, it pays to get some expertise on your side," Keplinger says. He says that, on many wireless jobs, the people have a good understanding of cable, power and terminal strips, but no understanding of wireless. "They know how to crimp a ferule on a wire, and that's it," he says. Gary Grimes, vice president and general manager of the Microcell Management Division, LCC, Laurel, Md., has a solution for that: references. His firm typically hires contractors to do jobs. "I don't believe in giving the work to the lowest bidder," he said. "It really comes down to experience and work record on past projects." Since most companies are willing to share information on everyone else, Grimes says providing good references is critical to winning a contract with him. Proxim, like most other vendors, offers a short course for resellers and installers that addresses systems engineering and the idiosyncrasies of their own products. "There are a number of vendors, each with their own visions," Orr said. "No one solution is right for all segments of the market." For example, their commercial product typically covers a cell about 300 feet in diameter. The residential product is rated at 150 feet, or enough to cover a typical 2,500-square-foot home. Ratings should be more conservative in the home, because an average home has a lot more interference generators. Unforeseen problems can arise, too. For example, wireless LAN devices typically operate in the 2.4 GHz band, which is unlicensed. Therefore, other devices can legally interfere. Jellum says it is important to check noise and signal-to-noise ratios and to re-set channels to different frequencies if there is interference. Jellum recommends using Channels 1, 6, and 11. He also points out that wireless works in concentric circles. So, don't be surprised to find that the system delivers the full 11Mb inside the first 50-foot circle, but only 5.2 Mb at 150 feet and perhaps 2 Mb at 400 feet. "If certain users demand high throughput, concentrate the Access Points close to those who require higher speeds," Jellum advised. Common errors Not every job is a slam-dunk. "The most common error I see is improper installation of the coaxial cable connectors," said Keplinger. Next on his list of common foul-ups is improper installation of data communications interconnections. "This includes both mechanical, such as soldering, and trying to use incompatible protocols," he says. He blames insufficient installer training as the reason installers unwittingly link incompatible protocols. When he is called on to a job site where there are problems, the first thing he checks is the coaxial connections and the antenna. "If it's not done right, it hoses the system," he says. Keplinger recommends checking to see if the system requires a hardware handshake. Grimes maintains that, fundamentally, the projects he works on are no different than any other jobs … even if they involve towers and radios. "We follow plans and specifications. There are different types of electrical work," he said. "Much of it is identical with civil construction, like bringing in the power and hooking up meters." Right now, whether the wireless is used in-building or in a remote location, all systems eventually are connected with wired hardware/software within a building. Instead of panicking at the thought of wireless technology, contractors should learn about it and include it in their capabilities. It is just another way of transmitting communications through an energy-driven source. Keplinger maintains that all of the required skills can be learned. "It's not that it can't be learned-the military learned it," he says. However, he emphasizes, it is important to have someone who understands wireless and radio to be sure the job is done correctly. Consider the rewards of uncabling your installation business. Wireless can put some sweet fizz in the bottom line of your firm's checkbook. Drink up! HARLER, a contributing editor to Electrical Contractor, is based in Strongsville, Ohio. He can be reached at (440) 238-4556 or charler@compuserve.com.

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