You are presented with multiple paper abstracts, alongside the associated literature review and chapter titles. Given the provided information, you are going to do a literature review. Please generate a coherent literature review that synthesizes the content, draws connections between different works, highlights major findings, and identifies any gaps in the existing research.

Literature Review Title: Multimedia Internet of Things: A Comprehensive Survey 
Chapter Title:  2) MULTI-HOP ROUTING 
1. Abstract of Cited Paper (BIB001):  Multimedia transmissions for IoT (Internet-of-Things) sensing has a high demand of route capacity and tight requirements of end-to-end delay. In this paper, we address the problems on how to guarantee delay-related QoS requirements and to balance the energy consumption, while using multipath routing to offer high transmission capability for IoT multimedia sensing. This motivates us to design a Multipath Planning for Single-Source based transmissions routing scheme, namely MPSS, which establishes desirable multiple route paths following B-spline trajectories based on geographical information of source and sink node, sending and receiving angles, and inter-path distance. We further utilize a factor of hop distance to reduce the cumulated error of each hop due to the density of nodes, and to guarantee the delay-related QoS requirements. A Multipath Planning for Multi-Source routing scheme is also designed, namely MPMS, to assign the angle scope according to the source node's priority and traffic. Experimental results show that MPSS can effectively generate well-patterned multiple spline-based routes, and the end-to-end delay is under control according to the delay QoS requirement, while the total energy consumption is minimized. 
2. Abstract of Cited Paper (BIB002):  With the development of wireless communications and the intellectualization of machines, the Internet of Things (IoT) has been of interest to both industry and academia. Multihop routing and relaying are key technologies that will underpin IoT mesh networks in the future. This paper investigates optimal routing based on the trusted connectivity probability (T-CP) for multihop, underlay, device-to-device (D2D) communications with decode-and-forward relaying. Both random and fixed locations for base stations (BSs) are considered, where the former case assumes that the locations of the BSs are modeled as a Poisson point process (PPP). First, we derive two expressions for the connectivity probability (CP): 1) a tight lower bound and 2) an exact closed-form. Analysis is carried out for the cases where the channel state information (CSI) between BSs and the D2D transmitter is known (CSI-aware) and unknown (no-CSI). Interference from active cellular user equipments (CUEs) is characterized by modeling CUE locations as a PPP. Moreover, motivated by results that have shown that social behavior leads to D2D devices communicating with nearby neighbors, we derive the trust probability for D2D connections by using a rank-based model. Finally, we propose a novel routing algorithm that can achieve the highest T-CP for any pair of D2D devices in a distributed manner. The derived analytical results are verified by Monte Carlo simulations. We show that the proposed routing algorithm achieves almost the same performance as that attained through an exhaustive search. When BSs are located randomly, the optimal path based on the CP is the shortest path between the D2D transmitter and receiver. However, for fixed BSs, the optimal path selection depends on the locations of the BSs, which provides a very useful insight in designing the multihop D2D system for 5G IoT.

Literature Review:
The real-time multimedia applications demand a probability of zero percent delay violation. A cooperative relaying model incorporating Cognitive M2M Network (CM2MN) is proposed in BIB001 for effective end-to-end QoS. Probabilistic forwarding protocol (PFP) based on a network-aware routing algorithm for multi-hop routing is presented. Cooperative Quality Controller (CQC) is formulated to guarantee QoS requirements. The opportunistic relay selection as a routing extension is based on the M/M/1 queueing model with First-Come-First-Serve (FCFS) strategy. Chen et al. BIB002 presented Multipath Planning for the Single source (MPSS) and Multiple Sources (MPMS) for multimedia transmission in IoT. The proposed work is based on B-spline trajectories. MPSS comprises two units that are the calculation of the hop count module, which determines the number of hops required to satisfy QoS delay and energy-saving module that determines the minimum power required to deliver the data successfully. Utilizing spline trajectories, the source can determine the direction of next-hop by integrating parametric functions for geographical routing. The aim is to determine multiple paths that satisfy QoS with minimum energy consumption. The optimum path with the least energy consumption is selected. The performance of the system is evaluated based on end-to-end delay and energy consumption. Chen et al. in BIB003 devised a Trusted Connectivity Probability (TCP) based D2D relay selection model for routing data in a multi-hop manner. A ranking model is adapted to select the next-hop node with the highest rank. Rank is allotted based on Trust Probability (TP) that depends on the geographical distance between the current and next-hop nodes. An optimization problem is formed to select the optimal route with maximum TCP. The problem is solved with the help of the Dijkstra algorithm that determines the TCP value from a source node to all the nodes in the network. The model offers the D2D communication in both Channel State Information (CSI) aware and unknown condition to calculate the minimum power required to transmit between D2D device and BS.