Multimedia Internet of Things: A Comprehensive Survey <s> 3) MULTIMEDIA CONTENT STREAMING INCLUDING SURVEILLANCE <s> Wireless Multimedia Sensor Networks (WMSNs) are recently emerging as an extension to traditional scalar wireless sensor networks, with the distinctive feature of supporting the acquisition and delivery of multimedia content such as audio, images and video. In this paper, a complete framework is proposed and developed for streaming video flows in WMSNs. Such framework is designed in a cross-layer fashion with three main building blocks: (i) a hybrid DPCM/DCT encoder; (ii) a congestion control mechanism and (iii) a selective priority automatic request mechanism at the MAC layer. The system has been implemented on the IntelMote2 platform operated by TinyOS and thoroughly evaluated through testbed experiments on multi-hop WMSNs. The source code of the whole system is publicly available to enable reproducible research. <s> BIB001 </s> Multimedia Internet of Things: A Comprehensive Survey <s> 3) MULTIMEDIA CONTENT STREAMING INCLUDING SURVEILLANCE <s> Multimedia services over resource constrained Wireless Sensor Networks (WSNs) face a performance bottleneck issue from the gateway node to the sink node. Therefore, the queue management at the gateway node is crucial for diversified messages conveyed from the front nodes to the sink node. In this study, we focus on the performance improvement upon different traffic loads over WSNs. A dynamic adaptation scheme based on adjusting Beacon Interval (BI) and Superframe Duration (SD) in the IEEE 802.15.4 MAC superframe accompanied with RED (Random Early Detection) queue management scheme is proposed to increase the transmission efficiency of multimedia over WSNs. Evaluation metrics include end-to-end delay, packet delivery ratio and energy consumption in IEEE 802.15.4 beacon enabled and non-beacon enabled mode. Simulation results show that RED scheme accompanied with an appropriate setting of BO, SO value can effectively decrease end-to-end delay and energy consumption compared to the DropTail (FIFO) scheme. <s> BIB002 </s> Multimedia Internet of Things: A Comprehensive Survey <s> 3) MULTIMEDIA CONTENT STREAMING INCLUDING SURVEILLANCE <s> Surveillance applications with Wireless Sensor Networks can be strengthened by introducing imaging capability: intrusion detection, situation awareness, search&rescue. As images are usually bigger than scalar data, and a single image needs to be split in many small packets, image transmission is a real challenge for these applications, especially when knowing that the wireless medium in WSN has high throughput limitations and high packet loss rates due to numerous wireless channel errors and contention. Our contribution in this paper is on identifying limitations and bottlenecks of sensor board hardware and 802.15.4 radio to determine the performance level that can be expected when transmitting still images on a multi-hop network. In this paper, we will present experimentations with real sensor boards and radio modules. We will highlight the main sources of delays assuming no flow control nor congestion control to determine the best case performance level. The objective here is to present the potentials and the limitations of image-based wireless sensor networks. <s> BIB003
The development of the advanced and cost-efficient Complementary Metal-Oxide Semiconductor (CMOS) sensors has led to the widespread growth of visual and audio content across many platforms. Its impact is profound in the IoT domain as well and has led to the development of the Wireless Multimedia Sensor Networks (WMSNs) BIB001 . These WMSNs have found their application in surveillance and telemedicine. The constraints these networks face are in terms of computing power, energy supply, and memory. Additionally, they struggle with limited channel bandwidth and variable capacity. Lin et al. BIB002 propose a system to mitigate the challenges of the limited network capabilities in the multimedia framework. This involves a dynamic scheme to adjust the beaconing interval and the superframe duration. This dynamic approach helps in the network synchronization and efficient scheduling, thus, resulting in enhanced transmission efficiency. The proposed method is effective for a dynamic data load, as well. Pham et al. BIB003 have presented an evaluation of the IEEE 802.15.4 standard for the image transmission applications real deployment scenarios. The evaluation is a representative of the Universal Asynchronous Receiver Transmitter (UART) and Serial Peripheral Interface (SPI) based boards for surveillance. The authors present a compression scheme for Joint Photographic Experts Group (JPEG) format image data as well as a block interleaving scheme that enhances the reconstructive accuracy after encoding the images. The authors identify the possible bottlenecks that induce higher latency.