Bilal Muhammad Khan

Collision Free Mobility Adaptive (CFMA) MAC for wireless sensor networks

In this paper we propose high throughput collision free, mobility adaptive and energy efficient medium access protocol (MAC) called Collision Free Mobility Adaptive (CFMA) for wireless sensor networks. CFMA ensures that transmissions incur no collisions, and allows nodes to undergo sleep mode whenever they are not transmitting or receiving. It uses delay allocation scheme based on traffic priority at each node and avoids allocating same backoff delay for more than one node unless they are in separate clusters. It also allows nodes to determine when they can switch to sleep mode during operation. CFMA for mobile nodes provides fast association between the mobile node and the cluster coordinator. The proposed MAC performs well in both static and mobile scenarios, which shows its significance over existing MAC protocols proposed for mobile applications. The performance of CFMA is evaluated through extensive simulation, analysis and comparison with other mobility aware MAC protocols. The results show that CFMA outperforms significantly the existing CSMA/CA, Sensor Mac (S-MAC), Mobile MAC (MOB-MAC), Adaptive Mobility MAC (AM-MAC), Mobility Sensor MAC (MS-MAC), Mobility aware Delay sensitive MAC (MD-MAC) and Dynamic Sensor MAC (DS-MAC) protocols including throughput, latency and energy consumption.

Improved backoff algorithm for IEEE 802.15.4 wireless sensor networks

In wireless sensor networks (WSN) the medium access control CSMA/CA uses binary exponential backoff (BEB) algorithm to minimize collision among the contending nodes. The range of backoff exponent is limited to very small values. This causes channel access collision among the nodes resulting in degradation of quality of service. In this paper improved binary exponential backoff (IBEB) algorithm is proposed using interim backoff (IB) and unit interim period (IP) to minimize channel access collision by randomly waking up within the backoff time to sense the channel. The result shows that IBEB outperforms significantly the existing BEB algorithm employed in the IEEE 802.15.4 MAC standard as well as Linear/Multiplicative Increase and Linear Decrease (LMILD) and Multiplicative Increase Linear Decrease (MILD) schemes on variable network load and size.

Flying Ad-Hoc Networks: Technological and Social Implications

With the world turning into a global village due to technological advancements, automation in all aspects of life is gaining momentum. Wireless technologies address the everincreasing demands of portable and flexible communications. Wireless ad-hoc networks, which allow communication between devices without the need for any central infrastructure, are gaining significance, particularly for monitoring and surveillance applications. A relatively new research area of ad-hoc networks is flying ad-hoc networks (FANETs), governing the autonomous movement of unmanned aerial vehicles (UAVs) [1]. In such networks multiple UAVs are allowed to communicate so that an ad-hoc network is established between them. All UAVs in the network carry UAV-to-UAV communication and only groups of UAVs interact with the ground station. This feature eliminates the need for deployment of complex hardware in each UAV. Moreover, even if one of the UAV communication links breaks down; there is no link breakage with the base station due to the ad-hoc network between UAVs.

IWSN - Standards, Challenges and Future

Wireless sensor network (WSN) is a system that comprises thousands of wireless nodes spread around. These nodes use radio frequency (RF) channels to share their information and data, which may be further processed to monitor or control the system.

Improved quality of service in wireless sensor Network with mobile sink

Wireless Sensor Network (WSN) is an emerging field in the broader area of wireless networking; with application ranges from surveillance to health care. One of the major quality of service (QoS) degradation factor is last hop bottle neck in WSN, which results in low throughput and valuable energy depletion of the nodes; resulting in degradation of overall network lifetime and latency. This paper provides in depth simulation and analysis of sink mobility strategies to overcome the last hop bottle neck issue. We have investigated different sink mobility strategies with different speeds depending upon network load and traffic to bring optimized results. The paper is aimed in finding a substantial solution to the problem using cross layer protocols. Simulations are carried out in OPNET Modeler v 14.5 to investigate ZigBee (IEEE 802.15.4) various important quality of service parameters in WSN.

High Quality of Service and Energy Efficient MAC Protocols for Wireless Sensor Networks

Wireless sensor networks (WSNs) are increasingly gaining impact in our day to day lives. They are finding a wide range of applications in various domains, including health care, assisted and enhanced-living scenarios, industrial and production monitoring, control networks, and many other fields. In future, WSNs are expected to be integrated into the “Internet of Things”, where sensor nodes join the Internet dynamically, and use it tocollaborate and accomplish their tasks. As wireless sensor networks being used in many emerging applications the requirement of providing high quality of service (QoS ) is becoming ever more necessary. This highlights major issues like collision, scalability, latency, throughput and energy consumption. In addition mobile sensor network faces further challenges like link failure, neighbourhood information, association, scheduling, synchronisation and collision. Medium Access Control (MAC) protocols play vital role in solving these key issues. This chapter presents the fundamentals of MAC protocols and explains the specific requirements and problems these protocols have to withstand for WSN. The QoS is addressed for both static and mobile sensor networks with detailed case study of the IEEE 802.15.4 WPAN standard. Research challenges with literature survey and further directions are also discussed. The chapter ends with conclusions and references.

Mobility Adaptive Energy Efficient and Low Latency MAC for Wireless Sensor Networks

In this paper a high throughput, low latency, mobility adaptive and energy efficient medium access protocol (MAC) called Mobility Adaptive (MA) for wireless sensor networks. MAMAC ensures that transmissions incur no collisions, and allows nodes to undergo sleep mode whenever they are not transmitting or receiving. It uses delay allocation scheme based on traffic priority at each node and avoids allocating same back off delay for more than one node unless they are in separate clusters. It also allows nodes to determine when they can switch to sleep mode during operation. MA-MAC for mobile nodes provides fast association between the mobile node and the cluster coordinator. The proposed MAC performs well in both static and mobile scenarios, which shows its significance over existing MAC protocols proposed for mobile applications. The performance of MA-MAC is evaluated through extensive simulation, analysis and comparison with other mobility aware MAC protocols. The results show that MA-MAC outperforms significantly the existing CSMA/CA, Sensor Mac (S-MAC), Mobile MAC (MOBMAC), Mobility aware Delay sensitive MAC (MD-MAC) and Dynamic Sensor MAC (DS-MAC) protocols including throughput, latency and energy consumption.

A thin and flexible ultra wideband antenna for wireless body area networks with reduced ground plane effect

In this paper, the design, simulation and optimization study of a rectangular microstrip patch antenna (MPA) for ultra wideband (UWB) wireless body area network is presented. The UWB technology provides wideband wireless communication using very narrow pulses and at very low spectral densities. The Federal Commission of Communication allocates the bandwidth of ultra wideband from 3.1GHz to 10.6GHz for the unlicensed radio applications. The proposed antenna is designed and simulated in Agilent advance design system - momentum, an electromagnetic simulator that works on method of moment technique. The antenna is designed using RT/duroid 5880 (εr = 2.2 and h = 0.381mm), a thin and flexible substrate suitable for wearable antennas in body area networks and FR4 substrate (εr = 4.6 and h = 1.6mm). The dimensions of the proposed design for both the substrates is calculated using the well known transmission-line model. An offset feeding technique is used to feed the antenna. The maximum achieved antenna gain and bandwidth using RT/duroid 5880 substrate is 2.96dBi and 8.3GHz, whereas using FR4 substrate is 2.52dBi and 7.7GHz, respectively. The proposed design uses a reduced ground plane technique to achieve the wide bandwidth characteristic.

Mobility adaptive CSMA/CA MAC for wireless sensor networks

In this paper we propose high throughput low collision, mobility adaptive and energy efficient medium access protocol (MAC) called Mobility Adaptive (MA-CSMA/CA) for wireless sensor networks. MA-CSMA/CA ensures that transmissions incur less collision, and allows nodes to undergo sleep mode whenever they are not transmitting or receiving. It uses contention based as well as contention free period efficiently together to minimise the number of collisions cause by the mobile node entering and leaving the clusters. It also allows nodes to determine when they can switch to sleep mode during operation. MA-CSMA/CA for mobile nodes provides fast association between the mobile node and the cluster coordinator. The performance of MACSMA/CA is evaluated through extensive simulation, analysis and compared with the existing IEEE 802.15.4 industrial standard. The results show that MACSMA/CA outperforms significantly the existing CSMA/CA protocol including throughput, latency and energy consumption.

Development of Resin Infusion Process for Ultralight Large Composite Structures

Resin Infusion process is an affordable process for developing composite structures but resin impregnate is made difficult by its large size of engineering products. This research demonstrates development of large structures such as body of a high performance automobile in a single step resin infusion process. Three different scaled down models of the car were developed according to user’s technical requirements focusing on minimal weight, air drag and aesthetics. Pro E and ANSYS were used to determine the optimal shape, geometry, size, aesthetics and strength. The digital model of exterior shape of car body was developed through coordinate measuring machine using selected model instead of Pro-E modeling due to time constraints. The digitized data was used for development of Pro-E model. The Pro-E model was scaled up to generate CAD drawings for tool development. Different stations were marked on the model and sliced virtually for development of pattern. After developing pattern, the mold was manufactured from carbon and glass / polyester composites for prototype manufacturing of the car body. The prototype manufacturing involved placement of specific number of carbon layers as perform on female side of the mold. The vacuum sucked the resin through a number of carefully selected entry ports. Multiple resin delivery ports ensured effective resin distribution and impregnation. After curing the cutting, trimming and drilling operations were carried out to finish car body to actual size. Polyacrylic wind shield was thermoformed in convection current oven according to streamlined geometry of car body. The car body was integrated with the compatible floor panels and accessories. The crumble zone shock absorber in the bumper was manufactured using successive layers of Nomex® honeycomb and PVC rigid foam to dampen the accidental shock. The successful test runs were made to qualify the car body according to user’s technical requirements.