WMNs were one of the earliest adoptions of mesh technology. Alongside Wireless Ad-hoc Networks, they established a very practical foundation of mesh networking. By successfully implementing routing algorithms, WMNs were able to implement the technology on an industrial level. 

WMNs have a similar topology to mobile ad hoc networks, but they show slow or no mobility. In WMNs, a change in the topology occurs when a host leaves the network. WMNs also do not show tremendous traffic abnormalities because mesh networks are normally used under controlled circumstances. WMNs consist of different nodes with distinct working characteristics. The classification is as follows:

• Wireless mesh clients are typically the mesh nodes, such as laptops, computers, tablets, mobiles, and wearable tech devices
• Wireless mesh routers are the middle point between mesh clients and mesh gateways and route the traffic in a WMN
• Wireless mesh gateways are used to communicate with another WMN or with the Internet

Since they are an introductory topic, WMNs are not discussed in detail here. Let's move forward to the implementation of mesh networks in ZigBee.