Mobile nodes are organized randomly without any access point in Mobile Ad hoc Networks (MANETs). Due to the mobility of nodes, the network congestion occurs. So many congestion control mechanisms were proposed to avoid the congestion avoidance or reducing the congestion status. In this research work, we proposed to develop the Effective Congestion Avoidance Scheme (ECAS), which consists of congestion monitoring, effective routing establishment and congestionless based routing. The overall congestion status is measured in congestion monitoring. In routing establishment, we propose the contention metric in the particular channel in terms of, queue length of packet, overall congestion standard, packet loss rate and packet dropping ratio to monitor the congestion status. Based on the congestion standard, the congestionless based routing is established to reduce the packet loss, high overhead, long delay in the network. By extensive simulation, the proposed scheme achieves better throughput, packet delivery ratio, low end-to-end delay and overhead than the existing schemes.

Mobile Ad Hoc Networks consists of mobile nodes which are organized in a random manner. It can communicate with each other without any centralized infrastructure. Due to congestion, the packet loss is heavily occurred in the particular link. In order to avoid congestion, cross layer based congestion control scheme is proposed for reducing the packet losses in the network. The proposed scheme contains four phases. In first phase, the cross layer design is proposed to ensure that the information sharing can be done between the different layers in protocol stack. In second phase, the congestion detection scheme is explored which attains packet loss rate and congestion scale factor. In third phase, congestion control is achieved using cross layer approach. Here the congestion route is determined based on the path gain, buffer tenancy fraction. In fourth, new packet format is proposed. Each node maintains the congestion scale value, buffer tenancy fractional value. By extensive simulation, the proposed scheme achieves better throughput, congestion ratio, packet delivery ratio, low end to end delay and overhead than the existing schemes.

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The study focuses on preprocessing techniques of web mining. Considering this scope, the study has proposed and implemented an efficient data cleaning and unique user identification algorithms. Previously proposed data cleaning algorithm is a generalized approach and lacked transparency. An appropriate model has to be used to implement the new data cleaning algorithm. Over analysis of various related studies and suggestions made by eminent experts, the study finalized decision tree classification model, and appropriate model to implement the new data cleaning algorithm. Simplicity, ease in framing rules and ability to fragment complex decisions to solve a problem motivated to choose decision tree classification model to implement new data cleaning algorithm. Apart from this the study has also modified the previously proposed hash function, used to locate existing web users in web log server. A new error factor is introduced to remove memory address discrepancy. The modified hashing function along with binary search techniques is used to design the new unique user identification algorithm. Various experiments analysis is done using web log servers of eminent universities and colleges from United Arab Emirates and India. Results obtained prove the improved and better performances of the new rule based data cleaning and modified unique user identification algorithms.

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