Multimedia Internet of Things: A Comprehensive Survey <s> C. CROSS-LAYER PROTOCOLS FOR MULTIMEDIA ROUTING <s> Mobile multimedia networks are enlarging the Internet of Things (IoT) portfolio with a huge number of multimedia services for different applications. Those services run on dynamic topologies due to device mobility or failures and wireless channel impairments, such as mobile robots or Unmanned Aerial Vehicle (UAV) environments for rescue or surveillance missions. In those scenarios, beaconless Opportunistic Routing (OR) allows increasing the robustness of systems for supporting routing decisions in a completely distributed manner. Moreover, the addition of a cross-layer scheme enhances the benefits of a beaconless OR, and also enables multimedia dissemination with Quality of Experience (QoE) support. However, existing beaconless OR approaches do not support a reliable and efficient cross-layer scheme to enable effective multimedia transmission under topology changes, increasing the packet loss rate, and thus reducing the video quality level based on the user’s experience. This article proposes a Link quality and Geographical beaconless OR protocol for efficient video dissemination for mobile multimedia IoT, called LinGO. This protocol relies on a beaconless OR approach and uses multiple metrics for routing decisions, including link quality, geographic location, and energy. A QoE/video-aware optimisation scheme allows increasing the packet delivery rate in presence of links errors, by adding redundant video packets based on the frame importance from the human’s point-of-view. Simulation results show that LinGO delivers live video flows with QoE support and robustness in mobile and dynamic topologies, as needed in future IoT environments. <s> BIB001 </s> Multimedia Internet of Things: A Comprehensive Survey <s> C. CROSS-LAYER PROTOCOLS FOR MULTIMEDIA ROUTING <s> The futuristic trend is toward the merging of cyber world with physical world leading to the development of Internet of Things (IoT) framework. Current research is focused on the scalar data-based IoT applications thus leaving the gap between services and benefits of IoT objects and multimedia objects. Multimedia IoT (IoMT) applications require new protocols to be developed to cope up with heterogeneity among the various communicating objects. In this paper, we have presented a cross-layer protocol for IoMT. In proposed methodology, we have considered the cross communication of physical, data link, and routing layers for multimedia applications. Response time should be less, and communication among the devices must be energy efficient in multimedia applications. IoMT has considered both the issues and the comparative simulations in MATLAB have shown that it outperforms over the traditional protocols and presents the optimized solution for IoMT. <s> BIB002 </s> Multimedia Internet of Things: A Comprehensive Survey <s> C. CROSS-LAYER PROTOCOLS FOR MULTIMEDIA ROUTING <s> Abstract Nowadays, multimedia contents are widely used for various applications to ensure personal and public services. These contents are transferred through different kind of networks, from classical Adhoc networks to the recent Internet of Things (IoT). However, regardless the deployed network, the main goal remains the same: ensuring a better QoE and lower latency especially for emergency traffic. This domain attracts many research activities. In this paper, we tackle this challenging issue and we propose a cross-layer scheme to handle video streaming over wireless sensor networks. Our starting point is to provide a carrier sense aware disjoint multi-path routing protocol able to transmit efficiently video and regular data from many sources to a unique base station (BS). This protocol will cooperate with the application layer in order to provide a frame-aware solution to assign high priority to the most important frames and low priority for the least important ones. This priority concerns mainly the path that will be used by the frames and the queuing policy that will be applied. Our queuing policy involves enqueuing, dequeuing and congestion solving function in order to reduce video latency and enhance the reliability. Our scheme is explained through a theoretical study with illustrative examples. Many simulations have been conducted, they demonstrate improvements of some performance indicators such as packet data rate, delay, loss packet rate and user experience. <s> BIB003 </s> Multimedia Internet of Things: A Comprehensive Survey <s> C. CROSS-LAYER PROTOCOLS FOR MULTIMEDIA ROUTING <s> The Internet of Things is a networking framework which allows the physical objects to connect with existing networking infrastructure. Due to high heterogeneity of hardware and communication protocols present among the things, poses many areas of the layered architecture to be re-engineered. Existing cross layered architectures for Sensor/Ad hoc networks cannot be applied directly, as the network characteristics are different. Internet uses hierarchical architectures whereas the Sensor/Ad hoc networks use flat architectures. In our work, we propose a cross-layer architecture of data-link and network layers for delay sensitive applications, such that response time should be less. An agent-based architecture was looked in, to optimize the inter-relation among the things, to find an optimal path i.e., optimize the end-to-end delay. IoT network mainly follows star type of topology but sensor network is multihop. The results show that the methodology we started with will yield good results for delay sensitive applications. <s> BIB004 </s> Multimedia Internet of Things: A Comprehensive Survey <s> C. CROSS-LAYER PROTOCOLS FOR MULTIMEDIA ROUTING <s> Wireless sensor networks suffer from some limitations such as energy constraints and the cooperative demands essential to perform multi-hop geographic routing for Internet of things (IoT) applications. Quality of Service (QoS) depends to a great extent on offering participating nodes an incentive for collaborating. This paper presents a mathematical model for a new-generation of forwarding QoS routing determination that enables allocation of optimal path to satisfy QoS parameters to support a wide range of communication-intensive IoT’s applications. The model is used to investigate the effects of multi-hop communication on a traffic system model designed with a Markov discrete-time $M/M/1$ queuing model, applicable to green deployment of duty-cycle sensor nodes. We present analytical formulation for the bit-error-rate, and a critical path-loss model is defined to the specified level of trust among the most frequently used nodes. Additionally, we address the degree of irregularity parameter for promoting adaptation to geographic switching with respect to two categories of transmission in distributed systems: hop-by-hop and end-to-end retransmission schemes. The simulations identified results for the average packet delay transmission, the energy consumption for transmission, and the throughput. The simulations offer insights into the impact of radio irregularity on the neighbor-discovery routing technique of both schemes. Based on the simulation results, the messages en-coded with non-return-to-zero have more green efficiency over multi-hop IoT (without loss of connectivity between nodes) than those encoded with the Manchester operation. The findings presented in this paper are of great help to designers of IoT. <s> BIB005
Rani et al. BIB002 proposed a cross-layer protocol to minimize energy consumption and response time. The authors formulated a multi-objective optimization problem to minimize the end-to-end packet error rate, time, and energy. These parameters are interlinked and dependant on crosslayer parameters such as path loss, modulation scheme, BER, transmission power, ARQ, duty cycling, and network routing protocol. The optimization of these parameters requires cross-layer communication and coordination. Authors exploit the Minimum Energy consumption Chain-Based Cluster Coordination Algorithm (ME-CBCCP) presented in  , which finds the shortest path not only at the local cluster level but also takes the intercluster path into consideration. Bennis et al. BIB003 devised Efficient Queuing Multimedia (EQM), a cross-layer communication protocol for transmitting multimedia data over wireless networks. A carrier sense aware disjoint multipath routing protocol is presented to transmit high priority independent video frames by reserving 2-hops neighbor nodes for video frames. The routing layer coordinates with the MAC layer to be aware of priority video data. An enqueuing and dequeuing approach is presented to process high priority multimedia data first and scalar data at the last of the queue. The proposed work aims to reduce waiting for the time and energy consumption of wireless networks. Rosario et al. BIB001 proposed LinGO, QoE aware link quality and geographical beaconless opportunistic routing protocol for video transmission in IoT. Forwarding node selection and routing path are determined according to cross-layer parameters that are: 1) link quality indicator classified by packet reception ratio, 2) progress which is the Euclidian distance between forwarding node to the destination, 3) energy of the forwarding node. The proposed model increases the reliability by adding redundancy packets for high priority video packets which improve QoE. Devi et al. BIB004 proposed an agent-based cross-layer protocol for optimal path selection and reducing end-to-end delay to transmit important multimedia data with minimum latency. The proposed model exploits the agents to transmit the data when the channel consumes more time than a threshold time. Hassan et al. BIB005 presented a cross-layer framework to ensure QoS satisfaction. A channel access mechanism based on queuing model M/M/1 is formulated for the duty cycle to handle the packets of real-time applications. The impact of multi-hop communication is analyzed using PHY-MAC parameters that are transmission power, hop distance, path loss, and packet error ratio (PER) for adaptive switching between end-to-end transmission or hop-by-hop transmission scheme.