Waveguide-based technology solves Wi-Fi coverage difficulties in warehouses, factories

December 12, 2012 // By Jean-Pierre Joosting
Wireless Expressways, "WE", has developed and field tested a new, efficient, wireless distribution system that blankets indoor sites with highly reliable wireless coverage.

At the center of the system is a low-loss, low-cost, company-developed waveguide backbone. A typical WE system in a warehouse, for example, uses a single span of waveguide placed under the "red iron" roof structure and runs across the ends of rows of product aisles. Predetermined signal levels taken from variable signal couplers installed in ports along the waveguide feed aisle-matched antennas. Changes in stock levels on warehouse shelves have no effect on coverage since all aisles and areas are illuminated with separate high-level signals. Spot beams to special areas are easily provided where needed.

Dropout-causing signal shadows in the vicinity of production machinery in factories are eliminated. The system works with any 2.4 GHz transceiver that has antenna connectors, such as high/low-power Wi-Fi, ZigBee, or Bluetooth devices. Battery life of low-power sensors is improved and environmentally powered sensors are made feasible in difficult applications.

A software-based system simulator is used to predict all settings and signals. Typical system efficiencies exceed 80%. They are highly reliable, contain no power consuming devices, require no maintenance, and are constructed with materials acceptable for installation in HVAC plenum spaces.

Data throughput is increased by minimizing co-channel interference from internal and external-to-building on-channel sources. Radiation of signals off premises to "unfriendlies" is greatly reduced.

"Our strategy is to efficiently transport wireless signals to users by going around signal-absorbing warehouse racks, and over signal-scattering clutter to distribute wide-area signals to clients," comments Charles Becker, President of WE. "We view our waveguide systems as 'short-circuiting' space to supply equal, high-quality, high-speed signals to all users. The increased coverage is dramatic. Many of our system trials have been in large warehouses, a notoriously difficult WLAN environment. Tests show we can fully cover a typical 40,000 square foot warehouse containing eight 175 foot aisles and nine fully loaded racks with signals to clients that are 100-1,000 times greater than the power level required for full 11Mbps, 802.11b,g operation.