甚低功耗无线通信技术——ZigBe

ZigBee技术作为无线传感器网络的主要支撑技术获得人们广泛的关注。完整的ZigBee协议套件由高层应用规范、应用会聚层、网络层、数据链路层和物理层组成。网络层以上协议由ZigBee联盟制订，物理层和媒体访问控制（MAC）层采用IEEE80215．4标准。IEEE802．15．4物理层简单采用比特到符号映射技术、符号到码片序列转换技术、偏移正交相移键控（OQPSK）调制技术，无须信道编码等复杂算法；MAC层采用载波监听多址一冲突避免技术，支持休眠模式。整个协议的设计使得ZigBee技术具有数据传输速率低、功耗低、成本低等特点，更加适合于工业监控系统、传感器网络、家庭监控系统、安全系统等应用。

ZigBee-Very Low-Power Wireless Communication Technology

ZigBee, an important technology supporting wireless sensor networks, has drawn broad attention. A complete ZigBee's protocol suite consists of high-layer application specifications, the application convergence layer, the network layer, the data link layer, and the physical layer. ZigBee Alliance focuses on defining the protocols above the network layer. The Physical (PHY) layer and the Media Access Control (MAC) layer are defined by the IEEE 802.15.4 standard. The IEEE 802.15.4 physical layer adopts technologies of mapping from bit to symbol, conversion from symbol to chip sequence and Offset Quadrature Phase-shift Keying (OQPSK) modulation, avoiding such complex algorithms as channel coding. The IEEE 802.15.4 MAC layer adopts Carrier Sense Multiple Access with Collision Avoidance (CSMA-CA) technology and supports the sleeping mode. ZigBee enables low data rates, low power consumption and cost-effectiveness, and is more applicable to industrial monitoring system, sensor networks, home monitoring system and security system.