Coverage and QualityBy David Strom | Posted 2009-03-04 Email Print
For wireless applications to function properly, they require the right in-building coverage, which involves more than just proper antenna placement and access point design.
Coverage and Quality
Just because an enterprise has deployed wireless access doesn’t mean it’s optimized. At the Baptist Healthcare East hospital in Louisville, Ky., doctors were receiving their pages a few minutes late due to poor in-building cellular coverage. “A lot of the doctors had Nextel push-to-talk phones, but they only worked in the surgical areas of the hospital,” says Jim Laval, manager of corporate IT. “They wanted something that worked everywhere.”
The hospital deployed ADC’s InterReach Fusion and now has universal coverage and high-quality wireless signals. It is deploying new applications that depend on this wireless infrastructure. “Having a solid wireless infrastructure gives us a lot of potential for new applications that enhance staff productivity and improve the quality of our care,” Laval says.
As the number of different radio frequencies in an enterprise increases, deployments should make use of filters to mitigate interference. Proper construction of antenna arrays that can operate at low power levels and focus coverage on particular areas is also important. The goal is to keep coverage high without sacrificing signal quality and service.
That’s the solution adopted by MobileAccess, with its Universal Wireless Network products that combine multiple radio signals over a single antenna array. The company groups antennae by using lower power emitters and filters to separate the signals and mitigate interference.
Both InnerWireless and MobileAccess use a single antenna to support multiple wireless signals but make use of coaxial cabling to connect this antenna to the wiring closet on each floor. The Wi-Fi access points are kept in the wiring closets and are connected via coaxial cables to antennae that are mounted closer to the users.
This keeps IT infrastructure out of the ceilings and in more centralized areas, which can be protected and more easily maintained. It also removes these devices from public areas, where they may be tampered with.