802.15.4 的 ZigBee的区别和联系

1、概念
802.15.4是链路层协议（OSI二层），定义的目的是适应低功耗的需要，用在物联网中。实现点对点的通信。
ZigBee是网络层协议（OSI三层），目的是用来生成网络拓扑实现多个设备的通信，同时提供认证、加密、路由协议和一些其他的服务。
2、关系
ZigBee 仅仅在802.15.4上层的一种协议而已，其实还有好几个协议都使用它
3、ZigBee网络中仅仅是端点设备具有休眠功能。
下面是一些常见的问题和详细介绍。
IEEE 802.15.4 (intro)

This standard defines a communication layer at level 2 in the OSI (Open System Interconnection) model. Its main purpose is to let the communication between two devices.It was created by the Institute of Electrical and Electronics Engineers (IEEE), entity which main task is to set standards so that technological developments can count with a common platform of rules to be set over. In the Waspmote devices this protocol is set using the XBee 802.15.4 OEM Digi module.
ZigBee (intro)

This standard defines a communication layer at level 3 and uppers in the OSI model. Its main purpose is to create a network topology (hierarchy) to let a number of devices communicate among them and to set extra communication features such as authentication, encryption, association and in the upper layer application services. It was created by a set of companies which form the ZigBee Alliance. In the Waspmote devices this protocol is set using the XBee ZB Digi module.