Recent Trends in Communication Networks

In recent years there has been many developments in communication technology. This has greatly enhanced the computing power of small handheld resource-constrained mobile devices. Different generations of communication technology have evolved. This had led to new research for communication of large volumes of data in different transmission media and the design of different communication protocols. Another direction of research concerns the secure and error-free communication between the sender and receiver despite the risk of the presence of an eavesdropper. For the communication requirement of a huge amount of multimedia streaming data, a lot of research has been carried out in the design of proper overlay networks. The book addresses new research techniques that have evolved to handle these challenges

Application-aware Cognitive Multi-hop Wireless Networking Testbed and Experiments

In this thesis, we present a new architecture for application-aware cognitive multihop wireless networks (AC-MWN) with testbed implementations and experiments. Cognitive radio is a technique to adaptively use the spectrum so that the resource can be used more efficiently in a low cost way. Multihop wireless networks can be deployed quickly and flexibly without a fixed infrastructure. In presented new architecture, we study backbone routing schemes with network cognition, routing scheme with network coding and spectrum adaptation. A testbed is implemented to test the schemes for AC-MWN. In addition to basic measurements, we implement a video streaming application based on the AC-MWN architecture using cognitive radios. The Testbed consists of three cognitive radios and three Linux laptops equipped with GNU Radio and GStreamer, open source software development toolkit and multimedia framework respectively. Resulting experiments include a range from basic half duplex data to full duplex voice communications and audio/video streaming with spectrum sensing. This testbed is a foundation for a scalable multipurpose testbed that can be used to test such networks as AC-MWN, adhoc, MANET, VANET, and wireless sensor networks. Experiment results demonstrate that the AC-MWN is applicable and valuable for future low-cost and flexible communication networks. Adviser: Yi Qia

Review on Analysis of LTE and Cognitive Radio Network using OFDM signal

Long Term Evolution (LTE) and Cognitive Radio Network (CRN) are built to achieve high data rates with low latency and packet optimized system. Orthogonal Frequency Division Multiple Access (OFDM) is adopted as the access technology for LTE in modern technology. OFDM provides several techniques and advantages for spectrum allocations to network segments, intra-cell Radio Resource Management (RRM) using Dynamic Subcarrier Assignment (DSA), Adaptive Power Allocation and Adaptive Modulation (AM) methods, providing the means for a flexible RRM scheme capable to address the problems of the service or cell area and provide solutions for proper network adaptation