Abhijit Sharma

Applications of wireless sensor network in Intelligent Traffic System: A review

An Intelligent Traffic System (ITS) involves a much closer interaction between all of its components: drivers, pedestrians, public transportation and traffic management systems. Adaptive signal systems, driver advisory and route planning and automated vehicles are some of the goals set up to increase the efficiency of actual systems. Vehicular network became one of the most active and emerging fields of research during last decade. Its use in diversified applications (for example safe driving, congestion avoidance, parking assist system and even entertainment) will soon bring revolutionary changes in transportation system. In this paper we have reviewed applications of wireless sensor network towards developing an efficient system to control and manage smooth traffic flow.

Congestion optimized routing in unidirectional de Bruijn WDM networks in presence of node faults

In this paper the problem of reducing congestion in WDM networks based on unidirectional de Bruijn graphs has been addressed in the presence of node faults. We propose a polynomial time routing algorithm for reducing congestion and analyze its time complexity. Congestion is defined as the maximum of the number of lightpaths propagating through a link over all links in the network. Congestion optimization is important as it leads to optimization of the load λmax an important parameter of a lightpath request. Results of the algorithm are shown for de Bruijn networks with various sizes of lightpath requests both in the presence and absence of node faults. Finally we evaluate the performance of the algorithm by comparing the results with those from two other strategies, the greedy routing algorithm and the graph search routing algorithm. Comparisons show that the proposed routing algorithm is the best amongst the three both in the presence and absence of node faults.

MoveFree: A ubiquitous system to provide women safety

With surveys of what is happening around us, it is beyond any argument to state that women are not safe enough to move freely alone. It is high time for the women to give a good retort to the society and raise their voice against the crimes that are taking place regularly. Pervasive computing with its omnipresent nature is emerging with a revolutionary approach towards technological growth. Anything and everything of the surroundings can be made to act as a computing device using the concept of pervasive computing. This paper makes use of the ever-present nature of pervasive computing to provide security to women. The work of this paper aims at designing a pervasive system comprising of a wearable computer that will act as a guardian angel for women in danger. The design of the system makes use of body area sensors, Bluetooth communication, GPS, SMS and MMS, Internet connection and mobile database system. A machine learning approach based on supervised classification is used to determine whether a woman is in danger. A prototype of the system is implemented in android.

New call and handoff call management scheme for reuse partitioning based cellular systems

In cellular networks, blocking occurs when a Base Station has no free channel to allocate to a mobile user. There are two kinds of blocking. New call blocking refers to blocking of newly originated calls and the handoff dropping refers to blocking of ongoing calls due to the mobility of the users. From the users point of view, the service of a handoff request is more important, as the forced termination of an ongoing call is more annoying than the blocking of new calls. In this paper, an adaptive guard channel based call admission control scheme is proposed which also deals with the problem of non-uniform traffic demand in different cells of the cellular network. A common set of channels are determined dynamically which can be used simultaneously in all the cells. Cell tiers with different radii are used to cope with the interference introduced by using same set of channels simultaneously in all cells. The adaptive guard channels alleviate the considerable amount of increase in the new call blocking probability due to guard channels while it can still protect handoff calls. The performance of the proposed scheme is presented in terms of call blocking probability, call dropping probability and channel utilization. Simulation results show that the proposed scheme can reduce the call blocking as well as call dropping significantly in highly congested cell.

Load balancing scheme for wireless cellular networks

In cellular networks, while the motivation behind all basic channel assignment strategies is the better utilization of the available frequency spectrum with the consequent reduction of the call blocking probability in each cell, very few of them deal with the problem of non-uniform traffic demand in different cells which may lead to a gross imbalance in the system performance. Mobile users in hot cells (the cells with heavy traffic loads) may suffer from low throughput due to the load imbalance problem. In this paper, we propose a load balancing scheme where a borrowed channel can be used in borrower as well as in lender cell simultaneously. To cope with the interference introduced by channel borrowing, cell tiers with different radii are used. Simulation results shows that the scheme can effectively balance the load among cells of a cellular cluster.

A high throughput internet access protocol (HTIAP) for moving things in smart cities

In spite of regular usage of internet in our daily lives, we are yet to receive highly incessant internet connection while travelling from one location to another. This occurs as a result of frequent handoffs between base stations of cellular networks. A high throughput Internet access protocol (HTIAP) is proposed in this paper in order to provide uninterrupted internet connectivity to the mobile devices in transit. In the proposed protocol, a network of moving vehicles and stationary hosts (GPS enabled Wi-Fi hotspots), placed along the roadsides of a city is considered. The performance of this network infrastructure is evaluated using ONE (Opportunistic Network Environment) simulator. The simulation result is compared with Default Gateway Selection (DGwS) algorithms and QoS-balancing Scheme for Gateway Selection (QGwS) on the basis of Vehicle to Infrastructure (V2I) communication efficiency. Together with high throughput and low delivery delay, HTIAP also offers the mobile users travelling along the city to have incessant access to the Internet which the other existing approaches fail to provide.

Overview on Location Management in PCS Network: A Survey

Location Management is an important and key issue in any wireless communication network to deliver the services of mobile user and the network needs to keep track of that mobile user constantly. Two methods for location management exist-Location update (LU) and Paging. Both location update and paging takes huge cost in terms of bandwidth, battery power, memory space, computing time etc. More location updates reduce cost of paging and the vice versa is also true. Since the LU cost is much higher than the cost of paging, this paper focuses on location management using LU only. A thorough study of different existing LU procedures of location management process in Personal Communication Service (PCS) network and its related research work are presented in this paper.

CAC DPLB MCN: A Distributed Load Balancing Scheme in Multimedia Mobile Cellular Networks

Abstract The problem of non-uniform traffic demand in different cells of a cellular network may lead to a gross imbalance in the system performance. Thus, the users in hot cells may suffer from low throughput. In this paper, an effective and simple load balancing scheme CAC_DPLB_MCN is proposed that can effectively reduce the overall call blocking. This model considers dealing with multi-media traffic as well as time-varying geographical traffic distribution. The proposed scheme uses the concept of cell-tiering thereby creating fractional frequency reuse environment. A message exchange based distributed scheme instead of centralized one is used which help the proposed scheme be implemented in a multiple hot cell environment also. Furthermore, concept of dynamic pricing is used to serve the best interest of the users as well as for the service providers. The performance of the proposed scheme is compared with two other existing schemes in terms of call blocking probability and bandwidth utilization. Simulation results show that the proposed scheme can reduce the call blocking significantly in highly congested cell with highest bandwidth utilization. Use of dynamic pricing also makes the scheme useful to increase revenue of the service providers in contrast with compared schemes.

Implementation of high speed processor for computing convolution sum for DSP applications

In this paper, we report on transistor level (ASIC) implementation of high speed processor for the first time, for computing convolution sum (linear and circular) of two sequences. The convolution sum was calculated through the orientation of the sequences into array formation for parallel processing, owing towards high speed architecture design. The architectures were implemented and functionality was verified through spice simulator. The mathematical transformation along with binary coded decimal(BCD) arithmetic have been incorporated for the practical implementation of convolution sum, ensure substantial reduction of propagation delay in comparison with earlier reported architectures. The performance parameters such as propagation delay, dynamic switching power consumption were calculated through spice using 90nm CMOS technology. The propagation delay of the resulting 4-point linear convolution was only ~12.79ns and consumes ~27.56mW power with a layout area of ~9.06mm2. Moreover, performance parameters of 4-point circular convolution were ~14.8ns propagation delay with ~37.8mW switching power consumption.

Adaptive call admission control scheme with optimal resource allocation for multi-class cellular networks

There exists an increasing demand by an ever-growing number of mobile customers for transfer of rich media contents such as video conferencing, file transfer and retrieval service, e-mail, paging, fax in addition to simple voice calls. This requires very high bandwidth that cannot be provided by the current cellular systems maintaining quality of service QoS because of limited bandwidth capacity. In this paper, a new adaptive call admission control scheme is proposed for allocating bandwidth optimally as well as provisioning QoS to the mobile users so far as practicable. In addition to these services, the proposed scheme during congestion also attempts to maximise the number of served calls in a cell to satisfy maximum number of users. Extensive simulation results show that the proposed scheme outperforms the existing schemes in terms of call blocking probability, system delay and bandwidth utilisation.