A novel multirate media access control based co-operative scheme has been proposed. It has been observed that any co-operative scheme gives a better performance only if the helper nodes selected to, relay the transmission from source to destination are reliable enough. Murad Khalid et.al has already proposed a protocol [24] where more than one helper nodes are selected to improve the reliability, so that if one fails the other can be used as a backup. But in this paper focus is on selection of reliable helpers. If a helper node has a high data rate, has successfully relayed traffic in the past and also has some minimum amount of energy left , not only for relaying traffic for others but also to conduct its own transmissions, then it acts as a suitable candidate to be chosen as a helper node. Such a co-operatives scheme enhances the throughput, reliability and overall performance of the network.Simulation has been conducted to show that the proposed scheme performs better than the

Wireless sensor networks (WSNs) are novel large-scale wireless networks that consist of distributed, self organizing, low-power, low-cost, tiny sensor devices to cooperatively collect information through infrastructure less wireless networks. These networks are envisioned to play a crucial role in variety of applications like critical military surveillance applications, forest fire monitoring, commercial applications such as building security monitoring, traffic surveillance, habitat monitoring and smart homes and many more scenarios. Node capture attack is one of the most dreadful security attack exist in wireless sensor networks. An adversary steals cryptographic key or other confidential information like node’s id etc from a captured node to compromise entire network. So, Security of wireless sensor network is an important issue for maintaining confidentiality and integrity of wireless links. Now-a-days, researchers are paying attention towards developing security schemes against Node capture attack. Our survey provides deep insights of existing techniques that enhance the attacking efficiency of the node capture attack in wireless sensor network. It also analyzes various detection and key pre-distribution schemes for inventing a new scheme to improve resilience against node capture attack.

In an advanced wireless network, trust is desirable for all routing protocols to secure data transmission. An enormous volume of important information communicates over the wireless network using trusted dynamic routing protocol, which is the enhancement of the DSR (Dynamic Source Routing) protocol to improve trust. Previously fuzzy logic, genetic algorithm, neural network has been used to modify DSR and good result has been obtained in few performance indicators and parameters. In this work an SVM based trusted DSR have been developed and better results have been presented. This new novel on demand trust based routing protocol for MANET is termed as Support vector machine based Trusted Dynamic Source Routing protocol, performance of STDSR has been improved in term of the detection ratio (%) at different mobility and no. of malicious node variation.