A B C D E F G H I J K L M N O P Q R S T U V W X Y Z All
Sudheer, S. K.
- Design & Analysis of Wireless Network for Signaling and Safety in Railways
Authors
1 Vellore Institute of Technology University, Vellore, Tamilnadu, IN
2 Thanthai Periyar Govt. Institute of Technology, Vellore, Tamilnadu, IN
3 International School of Photonics, Cochin University of Science and Technology, IN
Source
Networking and Communication Engineering, Vol 2, No 3 (2010), Pagination: 101-108Abstract
Today’s world still follows the wired network in railways for signalling and control with least options for safety. But with the advent of new high speed mass transit system, deployment of a secure and highly fast signalling mechanism has become the need of the hour. Indian Railways is looking forward to start high speed bullet trains on trial basis. So, to present a novel solution for the system, this paper aims to design and analyse a wireless network, adapted from Railways’ network structure, which aims to have high throughput, less delay as various key features using ns2 (Network Simulator) software. For the best deployment of such wireless networks, we have introduced the concept of “ZONE FORMATION”. A concept of Modified MAC (M-MAC) over IEEE 802.11 MAC protocol has been proposed. M-MAC protocol with some reduction in frame over-head size, reduction in Contention Window size and a new Adaptive Back-off Timer help us to achieve necessary results. The designed network has a Hybrid topology with star topology and bus topology joined together using Term nodes. The results have been analysed using standard channel and Rayleigh fading channel after necessary modifications to get the results, and then later analysed the same with real data collected from survey in Delhi Metro Rail Corporation Ltd., New Delhi.
Keywords
Adaptive Back-Off Timer, Junction, M-Mac, Post, Term, Tts Algorithm, Zone Interface Post.
- Analysis of Air Core Index Guided Photonic Crystal Fiber
Authors
1 School of Electrical Sciences, VIT University, Vellore, TamilNadu, IN
Source
Networking and Communication Engineering, Vol 1, No 4 (2009), Pagination: 173-176Abstract
In this paper, two types of PCF structure are designed as air core index guided with three rings of three different diameters nmis numerically investigated, using finite element method (COMSOL Multi Physics3.2a). The impact of the air-core on the three parameters that is, effective mode index, confinement loss and birefringence behavior are studied for this two different types of structure. By destroying the symmetry of the structure and make effective index difference between two orthogonal polarization states, birefringence is achieved. By using different diameter of air- holes around the newly formed core, the confinement loss is reduced and birefringence becomes high. It is seen that the effective mode index decreases with increase in wavelength and birefringence decreases with increase in normalized frequency.