Topology Cluster-Tree Characterization

The network formation of th eIEEE 802.15.4 does not impose constraints on the topology. The ZigBee alliance uses the IEEE 802.15.4 layers to build a complete  protocol stack for the implementation of wireless sensor networks. ZigBee specifies the network layer for star, tree and peer-to-peer topologies. Starting from these, more complex cluster tree topologies can be formed. To control the network topology, ZigBee fixes the maximum number of routers and end-devices that each router may have as children and also fixes the maximum depth of the tree.In this paper, the authors simulate and analyze the IEEE 802.15.4 formation procedure in different network settings (single-sink and multi-sink scenario).

Download Quran mp3

Download AlQuran MP3 by Shiek Saad AlGhamidi

http://www.al-quran.ca/en_ghamdi.html

FORMMIT-Utaratu’s memorize AlQuran Program.

Channelization Scheme

The authors compares briefly the differences among physical layers and MAC of 802.15.4 vs. 802.15.4a. The goal of the 802.15.4a standard for low data rate networks is to provide joint communications and high accuracy positioning in future sensor networks. In the same time, IEEE 802.15.4b Task Group focused on refining 802.154 and completed its activities in 2006 by releasing an updated version of the original standard.