# Wireless Mesh Networking: An IoT-Oriented Perspective Survey on Relevant Technologies
## 3 Mesh in IEEE 802.11 Networks
### Applications  
IEEE 802.11-based mesh networks have been used for several applications, both alone or in combination with other radio technologies. For example, the use of IEEE 802.11 mesh networks has been investigated for indoor positioning, in combination with Ultra-Wide Band (UWB) technology [23]. In particular, an IEEE 802.11-based mesh backbone is used in in [23] to combine its high data-rate feature together with high-accuracy UWB-based localization, since it allows an easy and fast deployment in areas without existing infrastructures. Video surveillance scenarios have also been studied in the literature, using IEEE 802.11 mesh networking as enabling technology. In [24], a video surveillance system for a large outdoor area based on an IEEE 802.11s mesh network is described. More in detail, the authors mount a camera on a drone moving over the area of interest and sending the video to a control center. As the drone is a mobile node and is not always in visibility with the control center, some static IEEE 802.11s nodes are deployed on the ground guaranteeing mesh connectivity. In [25], a wide area surveillance mesh network aimed at preserving forests from fire is presented. The proposed system is based on an IEEE 802.11-based mesh network, which supports communications both inside and outside the area afflicted by the fire, thus enabling the surveillance of the environment and guaranteeing the communication between the nodes in the area.  
Other relevant results can be found for smart city scenarios, for example aiming at controlling street lights in order to reduce energy consumption [26]. In [27], the smart city intelligent transportation  
Figure 3: Main Babel packets. (a) Babel packet; (b) _Hello_TLV of Babel protocol.; (c) IHU TLV of Babel protocol.  
problem is considered and the authors propose an application scenario that utilizes a swarm of autonomous drones to assist transportation of emergency medical teams, and other entities in emergency situations (e.g., accidents or natural disasters). Their goal id to provide in a fast way a response to an emergency crisis, enabling communication between the participating smart vehicles and, then, helping in the following restoration actions. More in detail, the authors use IEEE 802.11p for the communications between vehicles and drones; and IEEE 802.11s to support the internal drone communications, building a drone-based Wi-Fi backhaul network. In [28], the focus is also on the intelligent transportation problem in smart city scenarios, suggesting IEEE 802.11s as the solution to connect autonomous vehicles as mobile nodes of a mesh network.  
Finally, IEEE 802.11-based mesh has been deployed to enable new scenarios in aerospace applications [29], with a comparison between HWMP, batman-adv, and other technologies, (e.g., WiMax). In [29], the authors conclude that both HWMP and batman-adv have significant flaws in terms of re-organization velocity and scalability. In the authors' opinion, wireless mesh networking is suitable for both non-critical and critical space applications and the ongoing research should focus on the development of more robust open source solutions, taking into account an improvement of the network performance.