Standards for Building Wireless Sensor Network Applications
Good design adds value faster than it adds cost.
—Thomas C. Gale
11.1 802.XX INDUSTRY FREQUENCY AND DATA RATES
The IEEE 802.15.4 is a standard that specifies the implementation details of medium access control (MAC) and the physicallayer (PHY) for low-rate wireless networks. It provides the fundamental lower network layers of a wireless network focusing on low cost and low speed typically associated with wireless sensor networks. Currently, it has been implemented by several networking solutions such as ZigBee, Wireless HART, and MiWi, which provide higher-level communication protocols in addition to the 802.15.4 standard. In this chapter, most of the focus will be on the ZigBee standard, due to its popularity among wireless networking vendors. A simple comparison of some wireless standards is shown in Fig. 11.1.
The ZigBee standard defines the security, networking, and application frameworks for an IEEE 802.15.4–based system. It creates a self-forming, self-healing mesh network capable of supporting thousands of wireless devices on a single network [1–3]. The ZigBee stack architecture is divided into five parts:
- Security service provider
- Application layer (support sublayer, framework, ZigBee device object)
- Network layer
- Datalink layer
- Physical layer