Wireless Ad-hoc Networks lies under the umbrella of IEEE 802.11 standard as well but unlike WLAN, they don't have a centralized hub/router. The devices are responsible for routing the packets across the networks. Wireless Mesh Network (WMN) is a sibling of Ad-hoc Networks with the only difference of traffic abnormalities and mobility. Ad-hoc networks are more dynamics as compare to WMN and they have more traffic irregularity than WMN.

In Ad-hoc networks, the device acts as a router to transmit traffic between peers if the destination device is not directly connected to the sender device. This formation of devices is reliable because each device is connected to another device in a mesh, giving alternate routes to any possible incoming packet. These networks are also self-organized, so if a device leaves the network, the network will reconfigure itself for new potential routes for forwarding packets. Due to their architecture, they are widely used in small and large networks. They run on TCP/IP based model and can easily be implemented in any lite-weight smart device.

Since they are connected to one another directly, they are also called peer-to-peer networks. The architecture of Ad-hoc networks is different than WLAN which brings advantage and disadvantage at the same time. Ad-hoc networks are fast and don't contain a single point of failure like a router, but they are more prone to network attacks. Ad-hoc networks are easily scalable networks where devices can come and go at their will. On the other hand, those devices are responsible for routing the packets, which make them weak for Man in the Middle attacks.

Wireless Ad-hoc Networks are further classified into five types:

• Mobile Ad-hoc Networks (MANETs)
• Smartphone Ad-hoc Networks (SPANs)
• Vehicular Ad-hoc Networks (VANETs)
• Internet-based Mobile Ad-hoc Networks (iMANETs)
• Military Mobile Ad-hoc Networks

The inclusion of Ad-hoc networks in the smart device makes them vulnerable because they normally contain personal and sensitive information. This brings a threat to the Internet of Things. On the other hand, Ad-hoc is almost the perfect topology for IoT devices as they are fast, scalable, easily maintainable and cheap.

To understand how a mesh is connected, consult the following figure: