ZigBee is an open wireless standard for low-rate networks. It is an IEEE standard 802.15.4 protocol. The physical layer radio operates at 2.4 GHz band carrier frequencies with direct sequence spread spectrum (DSSS). It supports a range of up to 70 m. Data transfer rate supported is 250 kbps. It supports sixteen channels.
A ZigBee topology contains three different types of devices: Personal area network (PAN) contains exactly one ZigBee coordinator. This device initializes the network, assigns addresses to all other participants, and acts as security manager, where necessary. Additionally, a PAN contains ZigBee routers and ZigBee end devices. ZigBee routers are able to forward packets dynamically, a basic requirement for building mesh networks. ZigBee end devices have no routing capabilities and have to be directly connected to a ZigBee router or the ZigBee coordinator. ZigBee end devices require less memory than other ZigBee devices because they do not need to store routing information. Also, they can switch off their receiver for several time intervals, which reduces the energy demand of the device.
Related: What is Fieldbus in Industrial Communication Networks?
ZigBee network is self-organizing and supports peer-to-peer and mesh networks. Self-organizing means that it detects nearby ZigBee devices and establishes communication and network. Peer-to-peer network means that each node at network functions as a requesting device as well as a responding device. Mesh network implies that each network functions as a mesh. A node can connect to another directly or through mutually interconnected intermediate nodes. Data transfer is between two devices in peer-to-peer or between a device and multiple devices in a mesh network.
Related: Features of HART Communication Protocol
ZigBee protocol supports a large number of sensors, industrial controllers, air conditioning, lighting devices, and devices for home and building automation.
Comments