# Exploiting Outage and Error Probability
## 2 Related Work
A set of potential relays is selected on the basis of RTS/CTS (MAC layer) signaling, then the best relay with minimum signaling overhead is selected as a relay. The numerical and simulation results verify the proposed scheme. In [18], the authors propose a relaying mechanism for the cooperation communication. The new relay mechanism comprises of three things: (1) It identifies relay node's reputation; (2) It calculates relay node's SNR; (3) It finds out the location of the particular relay node. Once all of the three parameters are identified, impact of each criterion on relay selection is then calculated with the help of entropy. [PERSON]'s entropy helps in formulating two vectors; one has the best values of each criterion and the other, worst. These vectors are then utilized by [PERSON] and [PERSON] divergence to measure dissimilarities between candidates relays nodes and ideal solution which implies that the chosen best relay lowest distance from the ideal solution which is positive and highest distance from the negative ideal solution. The paper [19] deals with the study performance of two way Amplitude and Forward (AF) cooperative relay networks over Weibull fading channels. This cooperative relaying technique has been discovered to mitigate the effect of fading in wireless networks. The author has derived tight closed form approximations for Overall Outage Probability (OOP) as well as average symbol error probability (ASEP). Parameters such as number of relays, power scaling, power scaling parameters with BPSK and QPSK modulation are varied and then simulated with respect to already calculated OOP and ASEP. The simulated results depict a variety of results such as: ASEP is reduced significantly when the number of relays are increased and so on. OOP and ASEP can be improved by increasing the values of the parameters which include fading severity and power scaling parameters and the overall number of relays. [PERSON] et al. in [20] propose a relay selection technique based on Decode-and-Forward (DF) relaying method. The relay node is selected by using the availability of the Channel State Information (CSI). The authors studied the closed form Symbol Error Rate (SER) for both M Phase Shift Keying (MPSK) and M Quadrature Amplitude Modulation (MQAM) to evaluate decode-and-forward transmission signals. Furthermore, the authors proposed the optimal power method for the relay selection which maximizes the Signal-to-Noise Ratio (SNR) to achieve good performance of the system. Simulation results shows that the SER decreases when the number of relay nodes are increased. In [21], [PERSON] et al. studied a joint optimization problem of relay node assignment and flow routing for simultaneous communication sessions. They formulated the problem as a Mixed Integer Linear Programming (MILP) problem and developed a solution based on branch and cut method. The orthogonal channel model is employed in multi-hop wireless network using Amplify-and-Forward (AF) relaying method. The network throughput (rate) is improved by considering Feasible Solution Construction (FSC) for feasible flow of information for cooperative relay node. Different routing protocols have been designed for underwater sensor networks due to the unique behaviour of underwater acoustic channels. In [22], the authors proposed the underwater opportunistic routing protocol, an opportunistic based routing scheme increases the goodput. The authors focused on two metrics: goodput and energy cost. Goodput is used to measure the amount of useful data received before the deadline and energy cost for per packet energy consumption. In proposed method the authors introduce a new metric EEL success, which is the end to end latency from source to destination when at least one forwarder successfully receives a data. Two step heuristic algorithm designed for forwarding set selection and relay prioritization is also the part of this paper.