# Energy Aware and Quality of Service Routing Mechanism for Hybrid Internet of Things Network
## 1 Introduction  
The rapid rise of the Internet of Things (IoT) [1; 2; 3] has led to considerable growth in the demand for video surveillance systems. Wireless Multimedia Sensor Networks (WMSNs) based on IEEE 802.11 mesh networks are effective and suitable solutions for video surveillance systems in detecting intrusions in specific monitored areas. While IEEE 802.11-based WMSNs support high-bitrate video transmission, they are inefficient in terms of energy consumption. The inefficiency in energy use is caused by the fact that the visual sensor node's radio interface is constantly on, even when it is neither transmitting nor receiving data. Therefore, the idle listening (IL) state results in a great deal of energy wastage [4; 5]. In order to resolve such energy inefficiency issues, we conducted research [6] and proposed a new hybrid IoT system through a convergence of WMSNs based on IEEE 802.11 mesh networks with the LoRa network to form an autonomous and high bitrate, energy-efficient video surveillance system capable of detecting and tracking an intruder. Using the advantages of a LoRa network (i.e., long-range, low cost, and low power consumption), we proposed in [6] that the LoRa network be used as an always-active network for preliminary motion detection and activation of visual sensor nodes in the network. Based on the sensed information, the LoRa network activates visual sensor nodes that are involved in surveillance and routing a video stream to the gateway, as well as completely turning off visual sensor nodes that are not required. Thus, usingthis mechanism, an ample amount of energy can be saved. The hybrid IoT network is shown in Figure 1, and a detailed description and operation of the hybrid IoT network is presented in [6]. The hybrid IoT network architecture simply enables the management of the energy consumption of the visual sensor nodes by switching them on and off as needed, and there should be a mechanism to determine which nodes turn on and off in the network. It is known that video surveillance applications require that the video captured by the visual sensor nodes in the mesh network is transferred to the gateway node using a routing mechanism. As a result, the involved visual sensor nodes must remain turned on and the remaining idle nodes must be turned off. In order for the routing mechanism to be energy efficient, energy awareness should be taken into consideration in the network protocol design of the mesh-connected visual sensor nodes. It is essential to determine which few amongst the visual sensor nodes are needed for surveillance and are involved in routing a video stream to the gateway without compromising QoS requirements. This allows for those involved nodes to be turn on, while turning off completely as many idle nodes as possible to save the global energy consumption of the network. Additionally, multi-hop wireless mesh networks suffer from the interference phenomenon, and providing quality of service is challenging in these networks since two links cannot transmit simultaneously if they interfere with each other [7; 8; 9; 10; 11; 12; 13; 14]. In order to support a wide range of QoS requirements, a routing mechanism needs to have a complex model in which the wireless network has multiple QoS metrics. Therefore, providing a guaranteed QoS is a great challenge due to the inherent limitation of the wireless mesh. Following the above, this paper proposes an energy-aware and QoS routing algorithm for mesh-connected visual sensor nodes in a hybrid IoT network. This is an advanced feature extension of a previous research paper [6]. The routing algorithm allows routing a set of video streams with guaranteed bandwidth and limited delay under the assumption that the end-to-end packet transmission delay is proportional to the number of hops in a path while optimizing the energy consumption of visual sensor nodes in the network.