Mobility Management in 4G Networks

Over the past 25 years, the evolution of the internet and the advances of wireless technologies have made a tremendous impact on lifestyle of people around the world. Together, these two factors have changed the way people communicate, work, and get their entertainment. In order to be always best connected for various applications, the network selection procedure in heterogeneous multi-access environment during vertical handover decision is intended to choose the most suitable network for mobile user. In this paper, a performance study using the fuzzy logic concept is done and the integration of UMTS and WiMAX network is taken as an example to show that the proposed vertical handoff decision algorithm is able to determine when a handoff is required, and selects the best access network that is optimized to network conditions, quality of service requirements, received signal strength, bandwidth requirements and user preferences

CFT: Co-operative file transfer algorithm for multi network interface sessions

File transfer is one of the important operations on the Internet. Generally files are transferred from one machine to another machine through one interface. File transfer can occur through multiple interface connections also. Protocols such as SCTP, transfers data in multiple data stream within a single connection and LFTP transfers file sourced from multiple servers to a single host. Here, we present the concept of using multiple network interfaces for transferring files from a single server. This would ensure the utilization of combined bandwidth of all the interfaces used, so that the rate of file transfer would increase considerably compared to single bandwidth transfer. In this work, we use two interfaces i.e, IEEE 802.3 (Ethernet) and IEEE 802.11 (WiFi) to accomplish the above task. We use a non pre-emptive context switching framework Twisted where threading is avoided for an effective resource utilization. The required file is downloaded utilizing two interfaces instead of one unlike normal file transfer. We analyze the improvement in performance by observing the time taken to download a file using two different interfaces (Ethernet and WiFi) and comparing that with a single interface download (using either Ethernet or WiFi) in real time scenario. We attempt to deal with the issue of when and how to connect through two interfaces which combines the bandwidths of both these interfaces, aiding in improving the performance of file transfer when compared to file transfer using single interface

The role of communication systems in smart grids: Architectures, technical solutions and research challenges

The purpose of this survey is to present a critical overview of smart grid concepts, with a special focus on the role that communication, networking and middleware technologies will have in the transformation of existing electric power systems into smart grids. First of all we elaborate on the key technological, economical and societal drivers for the development of smart grids. By adopting a data-centric perspective we present a conceptual model of communication systems for smart grids, and we identify functional components, technologies, network topologies and communication services that are needed to support smart grid communications. Then, we introduce the fundamental research challenges in this field including communication reliability and timeliness, QoS support, data management services, and autonomic behaviors. Finally, we discuss the main solutions proposed in the literature for each of them, and we identify possible future research directions