In the mobile age, the expectation is for “always–on connectivity,” a topic covered in great depth at the International Wireless Communications Expo held in March in Las Vegas. The latest technologies and issues were uncovered – terms like narrowbanding, 4G and mesh networks – but the main concern was getting more commercial buildings to convert to wireless hook-ups.
Why It’s Needed
Whenever wireless radio-frequency (RF) signals pass through a material, such as brick or gypsum board, they lose strength, explains Jack Daniel, a wireless consultant and educator based in Victorville, CA. RF distribution systems are used to keep signals robust inside structures.
In-building wireless (IBW) technologies require a few basic components. First, you need a donor antenna, usually mounted to the roof. Signals coming in and out run through a bidirectional RF amplifier (BDA), which boosts the power for both the downlink and uplink paths.
Inside the building, an RF distribution network – usually 50 ohm coaxial or fiber-optic cables – leads the signals to indoor antennas in wireless user locations. Taps, splitters and decouplers pull RF signal from the cables to the antennas. Daniel warns that RF signals lose strength in coaxial runs: “These losses increase with length and RF frequency,” he explains. “In most cases, the maximum usable length of a coaxial cable is less than 1,000 feet.” Fiber-optic cable works better for longer runs, he adds.
Last, the cables serve a single antenna or are tapped along the runs by multiple antennas as part of a distributed antenna system, or DAS. In the best case, the antennas are visible from every place users will need them, although RF signals can travel through a few gypsum walls and still work well. 800 MHz antennas are common indoors, and a new “narrowbanding” mandate by the Federal Communications Commission (FCC) requires that all radio systems migrate to narrowband channels – many are 12.5 kHz – by January 1, 2013.
That’s not the only restriction for in-building wireless, says Stu Overby, a senior director for Motorola and member of the In–Building Wireless Alliance (IBWA), Sterling, VA. Even as narrowbanding increases availability to users, new RF technologies and users are gobbling up available spectrum. Second, says Overby, some jurisdictions will restrict locations for transmitter sites.
Wireless Advantages for Buildings
Still, a number of benefits are driving the latest wave of IBW systems, says Overby. For commercial buildings, the biggest boost is to worker mobility, which can increase operational efficiencies for potential users such as hospital nurses or even teachers and students at schools. Building owners have used IBW as a way to differentiate their properties and to improve tenant retention. IBW also reduces cabling needs, which can improve operations and aesthetics in many facilities while also cutting costs.
Last, wireless hook-ups can be integrated with security and life safety plans. Public safety groups are rewarding IBW adoption, and insurers recently began offering discounts for property-and-casualty coverage to building owners with indoor wireless communications. The Homer Building in Washington, DC, among the first, earned a 7.5% reduction a few years ago by showing how its IBW would improve fire and life safety response, says Tommy Russo, chief technology officer with real estate developer Akridge.
The Homer Building illustrates how IBW completely transforms a commercial workplace. Inside, more than 40 clients and 1,000 people are working on any given day. “The wireless system ensures 99.9% coverage for voice, data, and emergency communications in all areas of the building,” says Russo, including elevators, stairwells, and a parking garage extending five levels below grade.
Akridge was an early adopter, bringing IBW to its portfolio beginning in 2006. “Whether it’s retrofit or new construction, wireless is the latest ‘must-have’ amenity in the commercial real estate industry,” said Matthew J. Klein, president of Akridge, enabling owners “to reduce operating expenses while providing cutting-edge amenities to our clients.”
Wireless providers and the groups like IBWA are convinced the technology is here to stay. “Indoor wireless coverage is no longer a nice-to-have convenience,” says Cathy Zatloukal, president and CEO of MobileAccess, an IBW supplier in Vienna, VA. “It’s a necessity for unlocking the ROI potential of emerging wireless applications.”
C.C. Sullivan (firstname.lastname@example.org) is a marketing communications consultant and contributing editor specializing in architecture, design, and construction technology.