Wireless Networking

Mobile VPN Architectures: Mobile IP, the more popular global mobility solution, was designed to support mobility of a single host. Even though the same protocol can be applied in the case of network mobility, providing connectivity to mobile networks introduces many issues related to the scalability, security and QoS. Instead, a mobile network can be cited as a remote site, trying to establish secured communication with the home network. This view of mobile network solves many issues related to QoS, security and scalability. The objective of this research topic is to explore the possibility of using different VPN techniques to provide connectivity for mobile networks.

Quantizing the Throughput Reduction of IPSec with Mobile IP: The demand for immediate access to information universally is increasing rapidly, leading to the desire for mobile access to the Internet. The Mobile Internet Protocol (Mobile IP) provides mobility to Internet users with some basic security features that are insufficient. Internet Protocol Security (IPSec) brings security to the network, but uses more bandwidth. The desire for mobility does not reduce the requirement for security and maximum throughput. The purpose of this research is to further examine the effects of different security algorithms on bandwidth in mobile scenarios.

Mobile MoGRE VPN: While the usage of IPSec based VPNs for the construction and maintenance of a mobile VPN is feasible, issues related to its scalability in terms of required resources and QoS provisioning limit its practical deployment. The research work in this area explores the usage of a MPLS over GRE (MoGRE) based VPN architecture to construct a mobile VPN that would provide scalable, yet secure connections between the mobile networks and their corresponding home networks.

Redistribution of routes between ad-hoc and infra-structured networks: Work in the area of mobility has either concentrated on ad-hoc only networks or an infra-structured only networks resulting in an impractical global mobility solution. The work in this research area aims at filling this gap by redistributing routes learnt from the infra-structured and the ad-hoc networks to provide global mobility.

Deployment of NAT with Mobile IP: The deployment of NAT with Mobile IP introduces a set of issues related the presence of the Home Agent or the Foreign Agent behind a firewall. Due to the usage of private addresses for the mobility entities, the mobile IP registration and packet forwarding mechanism fails completely. The current work explores possible solutions to this problem by using a UDP tunneling mechanism to provide mobility to mobile networks.

Ad-Hoc Routing Protocol Performance Evaluation: An ad hoc network can be considered as a collection of mobile nodes that dynamically form a temporary network in the absence of an infrastructure of any kind or centralized administration. Various routing protocols were proposed for networks of this nature. DSR and TORA are two prominent Ad-Hoc routing protocols that are being widely accepted. Both the routing protocols have their own advantages and disadvantages. It is important to determine the suitable routing protocol for the given scenario. Hence the performance of the two routing protocols under various network conditions was measured and compared. The parameters considered were the packet loss, throughput and average delay. It is observed that the routing protocols performed as expected and the authors were able to segregate the routing protocols based on their usage and characteristics.  No single protocol had a complete advantage over the other, the performances varied as per the network.  The protocols that discover routes on the fly are found to perform the best in scenarios involving high mobility.  The protocols that tend to have message complexity had a deteriorated performance.

PCF vs DCF: A Performance Comparison: Wireless LANs are gaining importance at a very rapid pace. The idea of being mobile and being connected to the infrastructured network is driving new innovations in this area. With the recent innovations in the field of Multimedia over Internet, the requirements of QoS support over Wireless LAN are becoming more stringent. Quality of Service in a wireless LAN is affected by a number of parameters like channel access method, physical/environmental conditions, number of nodes, distance etc. A proper selection of protocols/topology could help in maintaining/improving the QoS support of a wireless network. In this research work, the researchers analyze the effect of channel access method on the multimedia (voice) traffic. Two channel access methods, namely Point Coordinate Function (PCF) and Distributed Coordinated Function are for their QoS support. In the process of comparison, the authors have also studied the impact of codec selection on the network performance. The simulations were carried out using OPNET network simulator. Parameters like number of simultaneously supported voice calls, voice end-to-end delay, packet drop percentage were considered for comparison. In addition, the effects of multimedia traffic on the data traffic were also analyzed both analytically as well as through simulations. The simulation results indicate that using PCF for multimedia traffic would result in better performance.