Brahmjit Singh

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Papers by Brahmjit Singh

Comparison of Vertical Handover Mechanisms Using Generic QOS Trigger for Next Generation Network

International Journal of Next-Generation Networks, 2010

Next Generation Network (NGN) is envisage to integrate heterogeneous wireless systems. NGN is exp... more Next Generation Network (NGN) is envisage to integrate heterogeneous wireless systems. NGN is expected to have Quality as the major challenging issue. More specifically, NGN aims at providing guaranteed Quality of Service (QoS) and Quality of Experience (QoE) i.e. what quality a network provider can offer (or claims) & what quality user experiences. NGN user may be interested in changing its network operator or is forced to change the serving access point (AP) or base station (BS) in order to achieve a given level of QoE. Seamless transfer of user's service from existing operator to a new operator bearing dissimilar radio access technology is called Vertical Handover (VHO). VHO decision may depend on the popular signal to noise ratio (SNR) criteria or other performance metrics like bit error rate, delay, jitter etc or combination of these metrics. Performance of candidate target network depends on the type of traffic i.e. whether conversational, streaming, interactive or background is implemented. Therefore to optimise VHO mechanism, all these metrics & traffic types should be evaluated. Paper elucidates contemporary VHO approaches i.e. hybrid ANP/ RTOPSIS & Oliver blume method. Different Interworking scenarios & NGN testbeds are prepared considering Wi-Fi, WiMAX, UMTS etc. as the candidate networks. Neuro-fuzzy based MCDM weight assignment technique is applied & overall network cost function is computed based on Qualnet simulation. At the end of the paper investigation suggests that Blume algorithm is better than the hybrid ANP mechanism because it is simple to implement, more efficient (40% more accurate), quickly computed (20 times less) and more dynamic (application oriented).

format_quoteBlume algorithm outperforms hybrid ANP by being 40% more accurate, 20 times faster, and simpler in implementation.format_quote

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High performance hardware implementation of AES using minimal resources

2013 International Conference on Intelligent Systems and Signal Processing (ISSP), 2013

ABSTRACT Increasing need of data protection in computer networks led to the development of severa... more ABSTRACT Increasing need of data protection in computer networks led to the development of several cryptographic algorithms hence sending data securely over a transmission link is critically important in many applications. Hardware implementation of cryptographic algorithms are physically secure than software implementations since outside attackers cannot modify them. In order to achieve higher performance in today&amp;amp;#39;s heavily loaded communication networks, hardware implementation is a wise choice in terms of better speed and reliability. This paper presents the hardware implementation of Advanced Encryption Standard (AES) algorithm using Xilinx-virtex 5 Field Programmable Gate Array (FPGA). In order to achieve higher speed and lesser area, Sub Byte operation, Inverse Sub Byte operation, Mix Column operation and Inverse Mix Column operations are designed as Look Up Tables (LUTs) and Read Only Memories (ROMs). This approach gives a throughput of 3.74Gbps utilizing only 1% of total slices in xc5vlx110t-3-ff1136 target device.

Optimization of the Security-Performance Tradeoff in RC4 Encryption Algorithm

Wireless Personal Communications, 2016

In this paper, we have investigated different vulnerabilities in RC4 and its enhanced variants to... more In this paper, we have investigated different vulnerabilities in RC4 and its enhanced variants to overcome the security attacks. It is established that in spite of several proposals, RC4 is not secure enough and a trade-off is always sought between security and network performance for overall provisioning of the secure communication. The main goal of the work presented in this paper is the optimization of security-performance tradeoff. We have proposed three RC4 variants referred to as RC4-M1, RC4-M2 and RC4-M3. Security of the proposed schemes is analyzed in terms of randomness and computational complexity. All the proposed variants qualify the NIST statistical test suite of randomness satisfactorily. The proposed schemes also offer computational complexity in terms of greater number of operations relative to the existing variants. The strength of the proposed schemes has been analyzed against different cryptanalytic attempts and shown the resistance of proposed schemes against attacks. The security-performance tradeoff has been analyzed in terms of run time, CPU cycles consumed, energy cost, and throughput. Encryption time of the proposed schemes-RC4-M1, RC4-M2 and RC4-M3 is 30.1, 10 and 48.7 % less as compared to RC4? respectively. The results clearly indicate that the computation load of the proposed variants is significantly reduced as compared to the RC4?, concluding that the proposed schemes are computationally efficient. Our results and their analysis also recognize the suitability of the security algorithms for particular application areas.

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Reduced VHO latency using EVM measurement and ad hoc cooperation for heterogeneous ubiquitous networks

International Journal of Information and Communication Technology, 2013

Future heterogeneous network HetNet will allow mobile ad hoc network MANET to interoperate with W... more Future heterogeneous network HetNet will allow mobile ad hoc network MANET to interoperate with WiMAX/LTE/WCDMA/CRN, etc. and will prefer OFDM modulation scheme for better spectrum efficiency. The RF parts of these standards have to face major challenges viz. channel estimation under very strict low power transmission viz. MANET. To exploit the ubiquitous diversity of HetNet, mobile node MN of MANET will prefer to perform vertical handover VHO across the HetNet for better guaranteed QoS and optimal resource utilisation. Considering these design challenges, paper proposes an optimal VHO model to associate a neighbouring ad hoc node CoN to cooperate and perform some parts of the VHO procedure requiring large latencies, such as authentication L1/L2 and IP registration procedures L3 which are based on measurement of error vector magnitude EVM. Performance of proposed VHO architecture is compared with conventional VHO schemes in terms of VHO latency, average service disruption time and reject rate. Proposed algorithm significantly reduces overall VHO latency.

Analytical Performance Evaluation of Inter-System Handover

IETE Journal of Research, 2005

Résumé/Abstract In this paper, we analyze the behavior of inter-system handover between second ge... more

Handover Initiation Control Techniques in Mobile Cellular Systems

IETE Technical Review, 2003

Résumé/Abstract This paper presents the handover process in terms of radio propagation issues. It... more

EVM as Generic QOS Trigger for Heterogeneous Wireless Overlay Networks

International Journal of Wireless & Mobile Networks, 2010

Fourth Generation (4G) Wireless System will integrate heterogeneous wireless overlay systems i.e.... more Fourth Generation (4G) Wireless System will integrate heterogeneous wireless overlay systems i.e. interworking of WLAN/ GSM/ CDMA/ WiMAX/ LTE/ etc with guaranteed Quality of Service (QoS) and Experience (QoE).QoS(E) vary from network to network and is application sensitive. User needs an optimal mobility solution while roaming in Overlaid wireless environment i.e. user could seamlessly transfer his session/ call to a best available network bearing guaranteed Quality of Experience. And If this Seamless transfer of session is executed between two networks having different access standards then it is called Vertical Handover (VHO). Contemporary VHO decision algorithms are based on generic QoS metrics viz. SNR, bandwidth, jitter, BER and delay. In this paper, Error Vector Magnitude (EVM) is proposed to be a generic QoS trigger for VHO execution. EVM is defined as the deviation of inphase/ quadrature (I/Q) values from ideal signal states and thus provides a measure of signal quality. In 4G Interoperable environment, OFDM is the leading Modulation scheme (more prone to multi-path fading). EVM (modulation error) properly characterises the wireless link/ channel for accurate VHO decision. EVM depends on the inherent transmission impairments viz. frequency offset, phase noise, non-linearimpairment, skewness etc. for a given wireless link. Paper provides an insight to the analytical aspect of EVM & measures EVM (%) for key management subframes like association/re-association/disassociation/ probe request/response frames. EVM relation is explored for different possible NAV-Network Allocation Vectors (frame duration). Finally EVM is compared with SNR, BER and investigation concludes EVM as a promising QoS trigger for OFDM based emerging wireless standards.

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Cognitive Vertical Handover with cooperative gaming for optimal payoff in emerging wireless HetNet

2012 International Conference on Communications, Devices and Intelligent Systems (CODIS), 2012

Future Heterogeneous wireless network (HetNet) will foster cognitive Vertical Handover (VHO) to e... more Future Heterogeneous wireless network (HetNet) will foster cognitive Vertical Handover (VHO) to exploit the ubiquitous diversity which is defined as seamless transfer of a session between different Radio Access Technologies (RATs). Classical VHO mechanisms lacks to expedite the effect of spectrum sensing for network selection which greatly affects the Quality of Experience (QoE) of both Access Node (AN) and Mobile Node (MN). Therefore, Paper proposes Error Vector Magnitude (EVM), which measures error in modulation quality and characterizes neighboring ANs. To maximize the overall network resource utility, EVM based multi-tenderee bidding model is proposed which utilises cooperative game theory. Performance is compared with classical MADM bidding model in terms of network bid value and total HetNet payoff. Results show that EVM based bidding increases the payoff by ~ 49.3% when compared with classical MADM bidding model.

Optimal Network Selection in Heterogeneous Wireless Environment for Multimedia Services

Wireless Personal Communications, 2015

The complementary characteristics of different wireless networks make it attractive to integrate ... more The complementary characteristics of different wireless networks make it attractive to integrate a wide range of radio access technologies. Most of previous work on integrating heterogeneous wireless networks concentrates on network layer quality of service (QoS), such as blocking probability and utilization, as design criteria. However, from a user's point of view, application layer QoS, such as multimedia distortion, is an important issue. In this paper, we propose an optimal distributed network selection scheme in heterogeneous wireless networks considering multimedia application layer QoS. Specifically, we formulate the integrated network as a restless bandit system. With this stochastic optimization formulation, the optimal network selection policy is indexable, meaning that the network with the lowest index should be selected. The proposed scheme can be applicable to both tight coupling and loose coupling scenarios in the integration of heterogeneous wireless networks. Simulation results are presented to illustrate the performance of the proposed scheme.

format_quoteIntroduced a unique distributed scheme for network selection considering application layer QoS has been overlooked in existing studies.format_quote

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Hybrid Intelligent Routing in Wireless Mesh Networks: Soft Computing Based Approaches

International Journal of Intelligent Systems and Applications, 2013

Wireless Mesh Networks (WMNs) are the evolutionary self-organizing multi-hop wireless networks to... more Wireless Mesh Networks (WMNs) are the evolutionary self-organizing multi-hop wireless networks to pro mise last mile access. Due to the emergence of stochastically varying network environments, routing in WMNs is critically affected. In this paper, we first propose a fu zzy logic based hybrid performance metric co mp rising of link and node parameters. Th is Integrated Link Cost (ILC) is computed for each link based upon throughput, delay, jitter of the lin k and residual energy of the node and is used to compute shortest path between a given sourceterminal node pair. Further to address the optimal routing path selection, two soft computing based approaches are proposed and analyzed along with a conventional approach. Extensive simu lations are performed for various architectures of WMNs with varying network conditions. It was observed that the proposed approaches are far superior in dealing with dynamic nature of WMNs as compared to Adhoc Ondemand Distance Vector (AODV) algorithm.

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AntMeshNet

International Journal of Applied Metaheuristic Computing, 2014

Wireless Mesh Networks (WMNs) are emerging as evolutionary self organizing networks to provide co... more Wireless Mesh Networks (WMNs) are emerging as evolutionary self organizing networks to provide connectivity to end users. Efficient Routing in WMNs is a highly challenging problem due to existence of stochastically changing network environments. Routing strategies must be dynamically adaptive and evolve in a decentralized, self organizing and fault tolerant way to meet the needs of this changing environment inherent in WMNs. Conventional routing paradigms establishing exact shortest path between a source-terminal node pair perform poorly under the constraints imposed by dynamic network conditions. In this paper, the authors propose an optimal routing approach inspired by the foraging behavior of ants to maximize the network performance while optimizing the network resource utilization. The proposed AntMeshNet algorithm is based upon Ant Colony Optimization (ACO) algorithm; exploiting the foraging behavior of simple biological ants. The paper proposes an Integrated Link Cost (ILC) me...

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Real Time Available-Bandwidth Estimation (ABE) Algorithm Based Selection in Heterogeneous Network for WiMAX and 3G

2011 Fifth International Conference on Next Generation Mobile Applications, Services and Technologies, 2011

... Our current implementation supports WiMAX echolife dongle and 3G dongle as interfaces and dua... more

Cross Layer Based Dynamic Handover Decision in Heterogeneous Wireless Networks

Wireless Personal Communications, 2015

ABSTRACT Heterogeneous wireless networks encompass different radio access technologies to offer s... more ABSTRACT Heterogeneous wireless networks encompass different radio access technologies to offer services as per the requirements of the users at anytime and anywhere. In such networks, mobile users have to undergo vertical and horizontal handovers to realize seamless communication with guaranteed quality of service. In this paper, we propose cross layer based dynamic handover decision algorithm to maximize resource utilization and to attain high QoS. The parameters measured at different layers are used through media independent handover functionality to estimate handover requirement and to select an appropriate target network. Based on user’s preferences, different weights are assigned to handover decision parameters using fuzzy analytical hierarchical process. The weights, assigned to decision parameters, are made adaptive to call time, velocity of mobile user, type of application and remaining battery life of the mobile handset. A popular multiple attribute decision making technique, TOPSIS (technique for order preference by similarity to the ideal solution), is adopted to choose the most suitable target network. Numerical results are obtained through computer simulation for preference scores of different networks, security, end to end delay and available data rate, which show that QoS perceived by the end user is maintained consistently in varied conditions of the network and applications.

A prediction based handover trigger in overlapped heterogeneous wireless networks

2013 IEEE International Conference on Signal Processing, Computing and Control (ISPCC), 2013

ABSTRACT Heterogeneous wireless networks are envisaged to be an integration of different wireless... more ABSTRACT Heterogeneous wireless networks are envisaged to be an integration of different wireless networks and demand the ability of users to move from one network domain to another network domain seamlessly. These networks are overlapped by each other to some extent. An appropriate time to initiate Handover (HO) is required to be calculated based on the necessity of HO as well as availability of target network. The link down trigger and link up trigger are the points corresponding to the HO requirement and resource availability respectively. In this paper, a prediction based HO trigger is proposed to initiate HO procedure at appropriate time. Matlab Simulation results demonstrate significant improvement in HO performance in different network overlapping environments.

WiMAX Network for Capacity and Coverage Assessment

Wireless Personal Communications, 2013

This article represents the system performance and its operation stability of a fixed worldwide i... more This article represents the system performance and its operation stability of a fixed worldwide interoperability for microwave access network operating with point to multipoint technology. It provides broadband access in fixed locations for mixed environments in Greater Noida, UP, India. The Field measurement for its capacity and coverage are recorded simultaneously to optimize a network by raising customer premises equipment (CPE) antenna height. This process is not going to alter any technical parameters of a network. CPE antenna is a directional antenna facing towards base station to achieve optimum LOS reception. The net changes in RSS 10-17 dBm, DTR 512-1.8 Mbps, path loss exponent 0.5-0.9 and standard deviation of 1.2-2.3 were observed by raising CPE antenna height of 2-5 m above the prescribed height. The path loss exponents for different environments are obtained using least squares method based on measured data by MatLab statistics tool. Standard deviations of signal strength variability with distance are derived. Real coverage of a network is presented based upon path loss exponent and standard deviation. Our result suggest that, raising the height of CPE antenna can reduce transmitted power, there for reducing overall maintenance cost and system interference in future.

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Performance Enhancement of Cellular Network Using Adaptive Soft Handover Algorithm

Wireless Personal Communications, 2010

Mobility management is the most important feature of a wireless cellular communication system. Co... more Mobility management is the most important feature of a wireless cellular communication system. Continuation of an active call is one of the most important quality measurements in the cellular systems. Handover makes it possible for a user to travel between various networks or cells while having a seamless connection. This paper shows that, performance of cellular network can be increased with proposed adaptive soft handoff algorithm, which dynamically calculates the Soft handover margin based on the received signal strength and distance. Performance is evaluated in terms of the performance metrics active set update rate, active set size, soft handover region and probability of outage. Simulation results show that soft handover algorithm gives better performance with adaptive soft handoff margin compared to that of fixed soft handover margin in varied propagation conditions.

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Network Selection Based on Weight Estimation of QoS Parameters in Heterogeneous Wireless Multimedia Networks

Wireless Personal Communications, 2014

ABSTRACT

Impact of L2 Triggering Time on Handover Performance for 4G Wireless Networks

Wireless Personal Communications, 2011

ABSTRACT 4G wireless networks are based on All-IP architecture integrating cellular networks, Wir... more ABSTRACT 4G wireless networks are based on All-IP architecture integrating cellular networks, Wireless local area networks, Worldwide Interoperability for Microwave Access, Wireless ad hoc networks, and Wireless Personal Area Networks etc. This makes seamless handover an important issue for users roaming among these networks. Anticipation of future events based on layer 2 (L2) trigger information is the basic principle of fast handover. It incurs higher signaling costs compared with the other protocols like Mobile IPv6 and Hierarchical Mobile IPv6. L2 trigger is based on fluctuating wireless channel states. Therefore, the handover anticipation using L2 trigger may sometimes be incorrect. Unnecessary buffer space is used for providing a smooth handover in the case of incorrect anticipation. Therefore, it is very important to analyze overhead costs and compare the performance of IP based handover protocols. This paper investigates the impact of L2 triggering time on the signaling cost, packet delivery cost, total overhead cost, and buffer space. Results show that Session to mobility ratio, L2 trigger time and number of subnets are determining parameters for optimizing handover performance.

Cross layer based fast handover for IEEE 802.16e networks

Optik - International Journal for Light and Electron Optics, 2014

ABSTRACT To guarantee the QoS in real time applications in wireless networks, handover delay is o... more ABSTRACT To guarantee the QoS in real time applications in wireless networks, handover delay is one of the most important parameters to be considered while mobile users are changing their point of attachment to the access networks. This calls for a fast handover mechanism that will be able to offer uninterrupted services to mobile users. In this paper, a cross layer based fast handover mechanism is proposed to reduce handover delay and signaling load in IEEE 802.16e wireless metropolitan area networks. This is achieved by overlapping the functions of Medium Access Control (MAC) Layer and Internet Protocol (IP) layer. The analytical results show that the proposed mechanism significantly enhances the handover performance in terms of handover delay and signaling load thus resulting into fast handover.

A New Empirical Formula for Handover Rate in Microcellular Systems

International Journal of Wireless Information Networks, 2005

In this paper, we propose a new empirical formula for handover rate as a function of base station... more In this paper, we propose a new empirical formula for handover rate as a function of base stations separation, standard deviation of shadow fading, path loss exponent, averaging distance, and correlation distance. The handover initiation algorithm is based on averaged signal strength measurements using relative signal strength with hysteresis margin approach. We generate the data through computer simulations for the average number of handovers referred to as handover rate, for the practical range of path loss exponent and standard deviation of shadow fading. The proposed formula provides for a practical design tool to optimize the handover initiation performance under varied propagation environments.

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