Underwater Wireless Sensor Networks (UWSNs) consist of certain number of sensors and vehicles interacting with each other to collect data. In recent years, the use of Autonomous Underwater Vehicle (AUV) has improved the data delivery ratio and maximized the energy efficiency in UWSNs. Clustering is one of the effective techniques in energy management which increases the lifetime of these networks. One of the most important parameters in creating optimized clusters is the choice of appropriate cluster head (CH), which not only increases the lifetime of the network and the received data in the sink, but also reduces energy consumption. Clustering of networks was primary done via distributed methods in previous researches. It spends too much energy and also involves too many nodes in the clustering process and fades their main functionality, which is gathering data in sensor networks. It also causes more damping of the network. However, in the proposed protocol, instead of having them distributed by the network and the nodes, the stages of clustering and selecting the appropriate CH is the task of the AUV (Autonomous Underwater Vehicle). Since all the necessary measures to cluster in the network will be carried out by the AUV by this method, many control overheads in the process of clustering the network will be removed and energy consumption caused by nodes reduces significantly. With this method, the network scalability will also be manageable and under control. For simulating and implementing our method we mainly used the OPNET software. The results show that energy consumption of nodes in the proposed algorithm has been significantly improved compared to previous results.

Multimedia communications in wireless sensor networks is a very challenging task. Video coding with high computational complexity and great contribution to the energy consumption of nodes and video transmission over erroneous wireless channel are the main reasons of these challenges. Distributed Video Coding has high potential for being deployed in these networks due to its unique features like as independent frame coding and low complexity encoding operations. The purpose of this study is to understand and evaluate the distributed video coding performance facing the transmission characteristics in wireless multimedia sensor networks. To this end, the comparative analysis of the coding in respect of main factors of video transmission (i.e., bit rate and error resiliency) in the Wireless Multimedia Sensor Networks (WMSN) has been done. We have used both the objective and subjective criteria for checking the video quality and applied the Gilbert-Elliot channel model for capturing the bit-level error in WMSN. Therefore, unlike previous works, our results are more realistic. In addition, based on this model we have investigated the impact of protection of frames by Reed-Solomon error control scheme. The results show that paying attention to coding parameters and protecting key frames, have a great impact on increasing the quality of the receiving video and will reduce the energy consumption and delays due to low number of requests from the feedback channel.

Capturing is the first step in intrusion detection system (IDS). Having wire speed, omitting the OS from capturing process and no need for making a copy of packets from the system’s environment to the user’s environment are some of the system characteristics. If these requirements are not met, packet capture system is considered as the main bottleneck of IDS and the overall efficiency of this system will be influenced. Presence of all these three characteristics calls for utilization of hardware methods. In this paper, by using of FPGA, a line sniffing and load balancing system are designed in order to be applied in IDS systems. The main contribution of our work is the feasibility of attaching labels to the beginning part of each packet, aiming at quick easy access of other IDS modules to information of each packet and also reducing workload of these modules. Packet classification in the proposed system can be configured to 2, 3, and 5 tuple, which can also be applied in IDS detection module in addition to load balancing part of this system. Load balancing module uses Hash table and its Hash function has the least flows collisions. This system is implemented on a set of virtex 6 and 7 families and is able to capture packets 100% and perform the above mentioned processes by speed of 12 Gbit/s.