## 1 Introduction
### Related Works  
This section presents a review of recent literature on routing protocol for wireless networks, which focuses on energy constraints, network stability, traffic congestion, and link failure among mobile devices. Optimized Link-State Routing (OLSR) is one of the most prominent routing protocols  
Figure 2: An example of a D2D communications scenario in 5G IoT networks. that provide loop-free paths for the wireless network and its applications [26]. Since its inception, it has been modified and improved over time by numerous scholars. One of its implementation, known as MP-OLSRv2 [27], focuses on discovering multiple paths between source and destination devices in order to utilize the available links and enhance the performance of the routing protocol. In another work carried out in [28], incoming data packets have been prioritized to each device such that the user's QoS requirements are met. On the other hand, QoS-based OLSR (QOLSR) utilizes the shortest-widest path algorithm to estimate the loop-free paths and improves the network performance by reducing the interferences among device-disjointed paths. The obtained results are supported by a comparison of single-path routing with multi-path routing schemes, however, multi-path routing schemes performed better than single-path QOLSR. In the article [29], the authors presented a header processing mechanism to reduce the control packets overhead information attached to each packet. The proposed mechanism ensured that the devices process the header more rapidly while consuming less energy in packets processing, which consequently saves energy for the whole network to be utilized later. This technique will not only save energy and processing time but also reduces the load on the network links since there are less data to be carried and improves the capacity of the individual link. The obtained simulation data indicated a significant improvement in the packet delivery ratio, while the authors further justified that the proposed algorithm performs better when the network is highly dynamic with frequent changes in the device position. In another study, an Energy-aware Multi-path Routing Protocol (EMRP) is presented in [30], where the device battery's residual energy information is exchanged within neighbor devices along with routing information. Hence, when the devices select the best paths, they will consider the residual energy of all the devices as well, which are present in the selected path(s). Also, devices provide update information to the neighbor devices regarding their queue length size, which determines the data packet load on a specific device. Thus, devices with a higher queue length size would consume their residual power more rapidly in comparison to devices with a low or minimal queue length size. In addition, devices with a larger queue length size cannot efficiently be part of new routes, as it will initiate the dropping of data packets once its queue is filled up. Therefore, combining queue length size and residual battery power to the routing metric will ensure that routing and traffic load is evenly divided among the network devices and no device will have a large queue length size. The relationship between energy consumed by the network and data packet collision in the medium or channel is presented in [31]. One of the significant causes of energy loss is by the data packets that are initially transmitted by the source device but never reached their destination due to channel impairments. The data packets that are either lost or delayed are required to be retransmitted by the source node; hence, energy is wasted on those data packets that are initially sent. The data packet loss is mainly due to a collision in the medium. Therefore, a collision sensitive routing protocol, Energy Efficient, and Collision-Aware (EECA) routing algorithm is proposed as an energy-efficient collision conscious multi-path routing for wireless sensor networks.