DefinePK

Abstract

ZigBee is a wireless standard recommended for low-data rate wireless personal area networks. ZigBee is widely used in much wireless Monitoring and control application domains due to its low cost, low power and implementation simplicity. ZigBee can work in a non-beacon-enabled mode using un-slotted Carrier Sense Multiple Access/Contention Avoidance (CSMA/CA) or a beacon-enabled mode using slotted CSMA/CA with or without guaranteed time slots (GTSs). GTSs can be allocated by the network coordinator to devices which require specific bandwidth reservation. Currently, there are many chip vendors, including Maxstream, Digi etc., producing commercially available products adopting the ZigBee specification. Wireless networks used in the industrial domain are expected to perform their operations smoothly under such a broad range of stringent operations conditions. As to the sensing networks designed for such purposes must consider the issues of co-channel interference, signal loss or fading due to metallic machinery, the presence of obstacles, the effects of variations of operating temperature, pressure, humidity, impact of noise and vibrations generated from engines, boilers, rotations of machinery, airborne contaminants etc., on the sensing and data communication ability of the network. This paper deals with the investigation of interference effects in Wireless Industrial Automation System (WIAS).