Formation and inter-piconet communications in cognitive personal area networks

This dissertation presents a new approach for achieving group rendezvous with a coordinator node towards forming a Cognitive Personal Area Network (CPAN) by an arbitrary number of nodes. We propose a protocol for the time to form CPAN in which the nodes join the coordinator simultaneously instead of sequentially. Specifically, we develop an analytical model and derive the distribution of time to form CPAN under the considerations of random arrivals of nodes and their random times to rendezvous with coordinator. We also investigate the CPAN formation time by considering the random activity of primary user (PU). Besides operating in a CPAN, the nodes may have traffic destined to the nodes of other CPAN. In this dissertation, we also propose a bridging protocol in which a shared (bridge) node routes the inter-CPAN traffic between two CPANs. As the bridge node shares its time between two CPANs, the bridge traffic gets priority over that of ordinary nodes in both CPANs. We consider a single, unidirectional bridge because the traffic in the opposite direction can easily be accommodated by having another bridge node. We develop an analytical model based on probabilistic modeling and queueing theory to evaluate the performance of the bridging protocol. We validate the network performance by analyzing the waiting time of local and non-local packets and how the node or bridge transmission is affected by the collision with primary source activity. Finally, we propose a low-overhead two-way bridging scheme for two-hop CPANs, which is more realistic and can be used a basis for routing inter-CPAN traffic in a multihop network. In this advance bringing protocol, the bridge switches between the CPANs without any predefined arrangement, which resulted in simplified bridge scheduling and increased fairness for all nodes. We also analyze its performance through probabilistic analysis and renewal theory. We show that the CPANs are indeed decoupled in terms of synchronization, however the performance of both local and non-local traffic in either CPAN depends on the traffic intensity in both CPANs as well as on the portion of traffic targeting non-local destinations

Formation and inter-piconet communications in cognitive personal area networks

This dissertation presents a new approach for achieving group rendezvous with a coordinator node towards forming a Cognitive Personal Area Network (CPAN) by an arbitrary number of nodes. We propose a protocol for the time to form CPAN in which the nodes join the coordinator simultaneously instead of sequentially. Specifically, we develop an analytical model and derive the distribution of time to form CPAN under the considerations of random arrivals of nodes and their random times to rendezvous with coordinator. We also investigate the CPAN formation time by considering the random activity of primary user (PU). Besides operating in a CPAN, the nodes may have traffic destined to the nodes of other CPAN. In this dissertation, we also propose a bridging protocol in which a shared (bridge) node routes the inter-CPAN traffic between two CPANs. As the bridge node shares its time between two CPANs, the bridge traffic gets priority over that of ordinary nodes in both CPANs. We consider a single, unidirectional bridge because the traffic in the opposite direction can easily be accommodated by having another bridge node. We develop an analytical model based on probabilistic modeling and queueing theory to evaluate the performance of the bridging protocol. We validate the network performance by analyzing the waiting time of local and non-local packets and how the node or bridge transmission is affected by the collision with primary source activity. Finally, we propose a low-overhead two-way bridging scheme for two-hop CPANs, which is more realistic and can be used a basis for routing inter-CPAN traffic in a multihop network. In this advance bringing protocol, the bridge switches between the CPANs without any predefined arrangement, which resulted in simplified bridge scheduling and increased fairness for all nodes. We also analyze its performance through probabilistic analysis and renewal theory. We show that the CPANs are indeed decoupled in terms of synchronization, however the performance of both local and non-local traffic in either CPAN depends on the traffic intensity in both CPANs as well as on the portion of traffic targeting non-local destinations

On Enhancing TCP to Deal with High Latency and Transmission Errors in Geostationary Satellite Network for 5G-IoT

The geostationary (GEO) satellite networks have two important influencing factors: high latency and transmission errors. Similarly, they will happen in the large-scale multihop network of the Internet of things (IoT), which will affect the application of 5G- (5th-generation mobile networks-) IoT. In this paper, we propose an enhanced TCP mechanism that increases the amount of data transferred in the slow start phase of TCP Hybla to mitigate the effect of long RTT and incorporates a refined mechanism of TCP Veno, which can distinguish packet loss between random and congestion. This scheme is evaluated and compared with NewReno, Hybla, and Veno by simulation, and the performance improvement of the proposed TCP scheme for GEO satellite network in the presence of random packet losses is demonstrated. At the same time, the enhanced TCP scheme can improve the transmission performance in the future 5G-IoT heterogeneous network with high delay and transmission .

Adaptive Joint Lossy Source-Channel Coding for Multihop IoT Networks

We consider monitoring applications in multihop wireless sensor networks (WSNs), where nodes rely on limited batteries so that energy efficiency and reliability are of paramount importance. Typically, lossy compression is aimed at saving transmission energy, yet affects the quality of transmitted data over lossy channels. Accordingly, using error correction coding (ECC) along with compression is required to guarantee both energy efficiency and high-fidelity reconstruction. In this paper, we analyze the energy efficiency of the joint use of lossy compression along with ECC, with the twofold objective of extending the network lifetime and assuring reliability. Specifically, we consider an adaptive joint lossy source-channel coding (JLSCC) system, where the energy efficiency and reliability performances depend on both the compression and the coding rates. Therein, we first carry out a performance analysis of JLSCC, considering realistic models of communication and computational energies, when the communication is performed over a Rayleigh fading channel. Then, we evaluate the performance of the JLSCC system compared to lossy compression and ECC systems in both end-to-end and multihop communications. Our results reveal that an adaptive JLSCC results in substantial energy saving while guaranteeing the required reliability performance, compared to both lossy compression and channel coding systems, that cannot be efficient for both energy and reliability. Instead, the JLSCC system is proved to be energy efficient for small distance end-to-end communication and large-scale multihop network, while leading to satisfactory reliability performance.

Dominating Set Based Clustering Algorithm for Mobile Adhoc Network

A group of mobile nodes using a common wireless media forms a dynamic multihop network known as Mobile Ad-Hoc network (MANET). Creating substructure (cluster) of the mobile adhoc network, basically divides the network into sub network. It has been observed that clustering of large size MANET improves the system performance to a large extent. Clustering allows the MANET to organize it in some hierarchy which reduces control overhead and make it scalable. This paper, gives a new scheme of clustering the MANET that uses the concept of dominating set. The cluster so formed by the proposed method is more stable (less mobile) than the earlier existing algorithms .Here the dominating nodes will be considered as the cluster head of a particular cluster. The non dominating nodes will select the most qualified dominating node as their cluster head and will join the cluster. The quality of the node is measured by its clustering co efficient