Digi International Inc XBEEPRO2 Manuel D’Utilisation

ZigBee is an open global standard built on the IEEE 802.15.4 MAC/PHY. ZigBee defines a network layer above the 
802.15.4 layers to support advanced mesh routing capabilities. The ZigBee specification is developed by a growing 
consortium of companies that make up the ZigBee Alliance. The Alliance is made up of over 300 members, including 
semiconductor, module, stack, and software developers.   

The ZigBee stack consists of several layers including the PHY, MAC, Network, Application Support Sublayer (APS), 
and ZigBee Device Objects (ZDO) layers. Technically, an Application Framework (AF) layer also exists, but will be 
grouped with the APS layer in remaining discussions. The ZigBee layers are shown in the figure below.

A description of each layer appears in the following table:

ZigBee defines three different device types: coordinator, router, and end device. 

Node Types / Sample of a Basic ZigBee Network Topology 

A coordinator has the following characteristics: it

•Selects a channel and PAN ID (both 64-bit and 16-bit) to start the network
•Can allow routers and end devices to join the network
•Can assist in routing data
•Cannot sleep--should be mains powered
•Can buffer RF data packets for sleeping end device children.

PHY

Defines the physical operation of the ZigBee device 

including receive sensitivity, channel rejection, output 

power, number of channels, chip modulation, and 

transmission rate specifications. Most ZigBee 

applications operate on the 2.4 GHz ISM band at a 

250kbps data rate. See the IEEE 802.15.4 

specification for details.

MAC

Manages RF data transactions between neighboring 

devices (point to point). The MAC includes services 

such as transmission retry and acknowledgment 

management, and collision avoidance techniques 

(CSMA-CA).

Network

Adds routing capabilities that allows RF data packets 

to traverse multiple devices (multiple "hops") to route 

data from source to destination (peer to peer).

APS (AF)

Application layer that defines various addressing 

objects including profiles, clusters, and endpoints. 

ZDO

Application layer that provides device and service 

discovery features and advanced network 

management capabilities.