The wireless devices for mobile applications and sensors
have small size with limited processing, communication and
energy capabilities. Thus, the new networks must support
low power and low data rate transmissions. Different
technologies were developed to fulfil the above mentioned
requirements. An example of these technologies is IEEE
802.15.4 networks, which is known as ZigBee networks.
ZigBee is for low cost solution which is being used
successfully in commercial application. To reduce the cost
of these networks they were designed to work in crowded
and overloaded 2.4 Ghz ISM commercial band with
different technologies such as IEEE802.11 known asWi-Fi.
The co-existence of different wireless technologies causes
interference and packets collision, then packet loss and