Mumbai University > Electronics Engineering > Sem 8 > Advanced Networking Technologies

Marks: 8M

1. The low rate (LR) wireless personal access network (WPAN) (IEEE 802.15.4/LRWPAN) is intended to serve a set of industrial, residential, and medical applications with very low power consumption, low cost requirement, and relaxed needs for data rate and QoS
2. The low data rate enables the LR-WPAN to consume little power. ZigBee technology is a low data rate, low power consumption, low cost, wireless networking protocol targeted toward automation and remote control applications.
3. The IEEE 802.15.4 committee and ZigBee Alliance worked together and developed the technology commercially known as ZigBee.
4. It is expected to provide low-cost and low-power connectivity for devices that need battery life as long as several months to several years but does not require data transfer rates as high as those enabled by Bluetooth.
5. ZigBee can be implemented in mesh (peer- to-peer) networks larger than is possible with Bluetooth. ZigBee-compliant wireless devices are expected to transmit 10–75 minutes, depending on the RF environment and power output consumption required for a given application, and operate in the unlicensed RF worldwide (2.4 GHz global, 915 MHz America, or 868 MHz Europe) bands.
6. The data rate is 250 kbps at 2.4 GHz, 40 kbps at 915 MHz, and 20 kbps at 868 MHz
7. The IEEE 802.15.4 committee is focusing on the specifications of the lower two layers of the protocol (the physical and data link layers).
8. ZigBee often uses a basic master-slave configuration suited to static star networks of many infrequently used devices that talk via small data packets. It allows up to 254 nodes.
9. Other network topologies such as peer-to-peer and cluster tree are also used.
10. When ZigBee node is powered down, it can wake up and get a packet in around 15 msec.