The Internet of Things (IoT) has dominated the digital world by enabling thousands of physical de... more The Internet of Things (IoT) has dominated the digital world by enabling thousands of physical devices to communicate with each other and share useful data over the Internet. With use cases spanning every sphere of modern life, the IoT is all set to revolutionize the traveling sector by extending services associated with safety, security, surveillance, tracking, comfort, and a lot more. This paper presents the design and implementation of a prototype Easy-Weigh-Out, based on the principles of the IoT which enables a user to run Android-based mobile application and view the weight of luggage and track its location without any contact with it. The hardware of the system is built around Arduino UNO microcontroller which interfaces with a load cell (20 kg) via A/D converter and a NEO-6M Global Positioning System (GPS) module for tracking of the bag. The system uploads data to a Cloud server using ESP8266 Wi-Fi module. Our results show the real-time weight and tracking of the bag at a cl...
Mobile Ad-hoc Networks (MANETs) are infrastructure-less networks comprising of nodes that are mob... more Mobile Ad-hoc Networks (MANETs) are infrastructure-less networks comprising of nodes that are mobile and do not have fixed interconnections. These distinctive features render conventional routing algorithms unsuitable for these networks and designing special routing protocols for MANETs is an important area for ongoing research. Routing protocols that have been proposed till now can be categorized into three types, reactive, proactive and hybrid. This paper explicates and compares three significant routing protocols for MANETs, one from each category. We analyze these protocols in terms of end to end delay through simulations performed in Network Simulator (ns2) for varying network conditions like network load, mobility and network size. Our results show that none of the proposed protocols clearly outperforms others under all conditions. Although AODV and DSDV perform better when network congestion is less and TORA performs better for congested networks, there is a need to design a ...
Mobile ad hoc networks are envisaged to play a vital role in ubiquitous networking owing to their... more Mobile ad hoc networks are envisaged to play a vital role in ubiquitous networking owing to their mobility support without relying on infrastructure-based design. Conversely, the same feature makes routing in these networks challenging as compared to the typical wired networks. As a result typical routing protocols designed for wired networks are not appropriate for these networks. A number of routing protocols have emerged over the last few years which can be generally classified as proactive and reactive routing protocols. In this research, we analyze and compare three most important routing protocols from both categories in terms of throughput, end to end delay and packet delivery fraction. This comparison is useful in understanding the requirements and challenges for routing protocols in mobile and ad hoc setting and forms the basis of designing a new routing protocol which we plan to present in future. Our simulation results based on simulations carried out using Network Simula...
Engineering, Technology & Applied Science Research, 2018
Internet of Things (IoT) is expected to play a major role in our lives through pervasive systems ... more Internet of Things (IoT) is expected to play a major role in our lives through pervasive systems of sensor networks encompassing our environment. These systems are designed to monitor vital physical phenomena generating data which can be transmitted and saved at cloud from where this information can be accessed through applications and further actions can be taken. This paper presents the implementation and results of an environmental monitoring system which employs sensors for temperature and humidity of the surrounding area. This data can be used to trigger short term actions such as remotely controlling heating or cooling devices or long term statistics. The sensed data is uploaded to cloud storage and an Android application accesses the cloud and presents the results to the end users. The system employs Arduino UNO board, DHT11 sensor, ESP8266 Wi-Fi module, which transmits data to open IoT API service ThingSpeak where it is analyzed and stored. An Android application is develope...
The reliability of data transfer is vital for commercial and enterprise applications of Wireless ... more The reliability of data transfer is vital for commercial and enterprise applications of Wireless Sensor Networks (WSN). Likewise, mission-oriented and critical military applications of these networks demand dependable and timely data transport. This ...
A mobile ad hoc network is a collection of autonomous mobile nodes that communicate with each oth... more A mobile ad hoc network is a collection of autonomous mobile nodes that communicate with each other over wireless links. Such networks are expected to play an increasingly important role in future civilian and military settings, being useful for providing communication support where no fixed infrastructure exists or the deployment of a fixed infrastructure is not economically profitable and movement of communicating parties is possible. However, since there is no stationary infrastructure such as base stations, mobile hosts need to operate as routers in order to maintain the information about the network connectivity. Therefore, a number of routing protocols have been proposed for ad hoc wireless networks. In this paper, we study and compare the performance of the following routing protocols AODV, PAODV (preemptive AODV), CBRP, DSR, and DSDV. A variety of workload and scenarios, as characterized by mobility, load and size of the ad hoc network were simulated. Our results indicate that despite its improvement in reducing route request packets, CBRP has a higher overhead than DSR because of its periodic hello messages while AODV's end-to-end packet delay is the shortest when compared to DSR and CBRP. PAODV has shown little improvements over AODV.
A data center is a facility with a group of networked servers used by an organization for storage... more A data center is a facility with a group of networked servers used by an organization for storage, management and dissemination of its data. The increase in data center energy consumption over the past several years is staggering, therefore efforts are being initiated to achieve energy efficiency of various components of data centers. One of the main reasons data centers have high energy inefficiency is largely due to the fact that most organizations run their data centers at full capacity 24/7. This results into a number of servers and switches being underutilized or even unutilized, yet working and consuming electricity around the clock. In this paper, we present Adaptive TrimTree; a mechanism that employs a combination of resource consolidation, selective connectedness and energy proportional computing for optimizing energy consumption in a Data Center Network (DCN). Adaptive TrimTree adopts a simple traffic-and-topology-based heuristic to find a minimum power network subset called 'active network subset' that satisfies the existing network traffic conditions while switching off the residual unused network components. A 'passive network subset' is also identified for redundancy which consists of links and switches that can be required in future and this subset is toggled to sleep state. An energy proportional computing technique is applied to the active network subset for adapting link data rates to workload thus maximizing energy optimization. We have compared our proposed mechanism with fat-tree topology and ElasticTree; a scheme based on resource consolidation. Our simulation results show that our mechanism saves 50%-70% more energy as compared to fat-tree and 19.6% as compared to ElasticTree, with minimal impact on packet loss percentage and delay. Additionally, our mechanism copes better with traffic anomalies and surges due to passive network provision.
A data center is a facility that houses computational and storage systems which are interconnecte... more A data center is a facility that houses computational and storage systems which are interconnected through a communication network. Although the earlier data centers comprised of interconnected servers and related equipment, the hierarchical design of Abstract A data center is a facility for housing computational and storage systems interconnected through a communication network called data center network (DCN). Due to a tremendous growth in the computational power, storage capacity and the number of interconnected servers, the DCN faces challenges concerning efficiency, reliability and scalability. Although transmission control protocol (TCP) is a time-tested transport protocol in the Internet, DCN challenges such as inadequate buffer space in switches and bandwidth limitations have prompted the researchers to propose techniques to improve TCP performance or design new transport protocols for DCN. Data center TCP (DCTCP) emerge as one of the most promising solutions in this domain which employs the explicit congestion notification feature of TCP to enhance the TCP congestion control algorithm. While DCTCP has been analyzed for two-tier tree-based DCN topology for traffic between servers in the same rack which is common in cloud applications, it remains oblivious to the traffic patterns common in university and private enterprise networks which traverse the complete network interconnect spanning upper tier layers. We also recognize that DCTCP performance cannot remain unaffected by the underlying DCN architecture hence there is a need to test and compare DCTCP performance when implemented over diverse DCN architectures. Some of the most notable DCN architectures are the legacy three-tier, fat-tree, BCube, DCell, VL2, and CamCube. In this research, we simulate the two switch-centric DCN architectures; the widely deployed legacy three-tier architecture and the promising fat-tree architecture using network simulator and analyze the performance of DCTCP in terms of throughput and delay for realistic traffic patterns. We also examine how DCTCP prevents incast and outcast congestion when realistic DCN traffic patterns are employed in above mentioned topologies. Our results show that the underlying DCN architecture significantly impacts DCTCP performance. We find that DCTCP gives optimal performance in fat-tree topology and is most suitable for large networks.
The smart grid delivers electricity from suppliers to consumers and uses bidirectional communicat... more The smart grid delivers electricity from suppliers to consumers and uses bidirectional communication to exchange real-time information between supply system and smart meters at the user end. With a combined communication infrastructure, smart grid manages the operation of all associated components to provide reliable and supportable electricity supply. The Neighborhood Area Network (NAN) of smart grid supports bi-directional data transfer between smart meters (installed at customer premises) and control center of the utility company through an aggregator. This communication suffers low throughput and excessive delays due to the Head of Line (HOL) blocking when the Transmission Control Protocol (TCP) is implemented for reliability. In this paper we propose SCTP-aware Link Layer Retransmission mechanism (SCTP-LLR) which augments the Stream Control Transmission Protocol (SCTP) with Link Layer Retransmissions at the aggregator. SCTP-LLR uses the multi-streaming feature offered by SCTP a...
IEEE 802.15.4 based Wireless Personal Area Networks (WPANs) are envisioned to play a vital role i... more IEEE 802.15.4 based Wireless Personal Area Networks (WPANs) are envisioned to play a vital role in the application centric ubiquitous networks. In IEEE802.15.4 networks, the use of non-interfering logical channels in multiple PANs, operating in a Personal Operating Space (POS) ensures to control the scope of PAN-directed broadcasts, reduce received energy per PAN device, and minimize interference at the physical layer. At the downside the inter-PAN communication is not possible with this setup as PANs in the same region remain unaware of each other's presence. This situation hinders sharing information of common interest amongst PANs and accessing infrastructure networks hopping through multiple PANs. In this paper, we present a comprehensive architecture enables neighboring PANs to communicate by diffusing into each other through border nodes. The basic idea is to time share logical channels to perform a gating operation by border nodes. Our contribution includes detection of border nodes, discovery of neighboring PAN(s), a common channel based gating protocol, interest diffusion and inter-PAN data transfer. We mathematically analyze the proposed architecture and carry out simulations in Network Simulator (ns2) for performance evaluation. Our simulations show that the proposed architecture gives optimal performance when multiple border nodes are able to perform gating.
EURASIP Journal on Wireless Communications and Networking, 2013
Lately, wireless sensor network applications have emerged for provision of commercial services to... more Lately, wireless sensor network applications have emerged for provision of commercial services to end users. This results in commercial deployment of sensor networks which is as an important research area due to a number of design and quality of service challenges. An important technical challenge for sensor service provision to end users is managing dynamic network conditions such as unreliability of sensor nodes and network links which results in frequent service outages. This research is aimed at addressing this challenge. It presents a novel architecture which utilizes the availability of multiple sensor networks under different administrative domains, deployed in an area such that maximum network connectivity and high service availability are ensured. The architecture incorporates modifications and enhancements at the medium access control and the routing layers of sensor nodes for the collaborative operation of sensor networks. The design is based on IEEE 802.15.4 standard and...
EURASIP Journal on Image and Video Processing, 2014
Visual sensor networks (VSNs) are innovative networks founded on a broad range of areas such as n... more Visual sensor networks (VSNs) are innovative networks founded on a broad range of areas such as networking, imaging, and database systems. These networks demand well-defined architectures in terms of sensor nodes and camera deployment, image capturing and processing, and well-organized distributed systems. This makes existing VSN architectures deficient because these are limited in approach and in design. In this paper, we propose VISTA, a distributed vision multi-layer architecture aimed at constructing the cumulative vision of mobile objects (MOs). VISTA realizes silhouette recognition of mobile targets through (a) premeditated deployment of sensor nodes (SNs) that are equipped with sonar sensors and fixed view (FV) on-board cameras present at the periphery of region of interest (RoI) and SNs with only on-board cameras within RoI, (b) pre-distribution of silhouettes of known objects across SNs, (c) sonar-based presence detection of MO at the outskirts of RoI, (d) MO silhouette capturing and matching at interior node to determine the % age match, (e) subsequent activation of next interior cameras in order to improve % age match, and (f) terminating further activation upon threshold recognition of MO. Experimental evaluation of our image processing algorithms against baseline algorithms with respect to execution time and memory shows significant reduction in image data and memory occupancy. Also, experiments show that true match is achieved fully under broad daylight conditions and large backgrounds when our proposed background subtraction and pixel reduction techniques are used. The mobility-driven behavior of associated network layer algorithms of VISTA is simulated in a network simulator (NS2) by representing the surety of MO identification as a function of number of cameras, database size and distribution, MO's trajectory, stored perspectives, and network depth. The simulation results show that doubling and, in some situations, manifold increase is observed in the surety of the target with an increase in the number of silhouettes deployed against the baselined database size and mobility model. The results substantiate that VISTA is a suitable architecture for low-cost, autonomous and efficient human and asset monitoring surveillance, friend-or-foe (FoF) identification, and target tracking systems.
EURASIP Journal on Wireless Communications and Networking, 2010
6LoWPAN (IPv6 based Low-Power Personal Area Network) is a protocol specification that facilitates... more 6LoWPAN (IPv6 based Low-Power Personal Area Network) is a protocol specification that facilitates communication of IPv6 packets on top of IEEE 802.15.4 so that Internet and wireless sensor networks can be interconnected. This interconnection is especially required in commercial and enterprise applications of sensor networks where reliable and timely data transfers such as multiple code updates are needed from Internet nodes to sensor nodes. For this type of inbound traffic which is mostly bulk, TCP as transport layer protocol is essential, resulting in end-to-end TCP session through a default gateway. In this scenario, a single gateway tends to become the bottleneck because of non-uniform connectivity to all the sensor nodes besides being vulnerable to buffer overflow. We propose SET; a management architecture for multiple split-TCP sessions across a number of serving gateways. SET implements striping and multiple TCP session management through a shim at session layer. Through analytical modeling and ns2 simulations, we show that our proposed architecture optimizes communication for ingress bulk data transfer while providing associated load balancing services. We conclude that multiple split-TCP sessions managed in parallel across a number of gateways result in reduced latency for bulk data transfer and provide robustness against gateway failures.
Blockchain-based Internet of Things (BIoT) is an emerging paradigm of Internet of Things (IoT) wh... more Blockchain-based Internet of Things (BIoT) is an emerging paradigm of Internet of Things (IoT) which utilizes the blockchain technology to provide security services to the IoT applications. In essence, the blockchain built-in security mechanism can provide services such as availability, authentication, authorization, confidentiality, and integrity to the IoT applications. While most of the IoT devices are inherently resource-constrained in terms of computational power and storage capacity, the downside for blockchain is a requirement of massive amount of energy and computational resources for its operation, which poses challenges to the realization of BIoT. This paper strives to explore the challenges associated with the integration of blockchain and IoT and review their solutions. First, a brief introduction of blockchain technology is presented, followed by characterization of blockchain-based IoT applications as per their heterogeneous traffic demand and Quality of Service (QoS) requirements. Next, challenges that limit the design, development, and deployment of BIoT applications are explained in detail such as energy efficiency, privacy, throughput, latency, fork problem, security, legal issues, smart contracts, storage, and network broadcast mechanism and their proposed solutions are discussed. Finally, future research directions of blockchain and IoT integration are indicated. This investigation will benefit the researchers and developers to identify and solve blockchain and IoT integration challenges in order to realize efficient BIoT applications.
AbstractIEEE 802.15.4 Wireless Personal Area Networks (WPANs) are envisaged to play an important... more AbstractIEEE 802.15.4 Wireless Personal Area Networks (WPANs) are envisaged to play an important role in future ubiquitous network applications. When multiple PANs operate in the same area called personal operating space (POS), they are not aware of each other's presence ...
The Internet of Things (IoT) has dominated the digital world by enabling thousands of physical de... more The Internet of Things (IoT) has dominated the digital world by enabling thousands of physical devices to communicate with each other and share useful data over the Internet. With use cases spanning every sphere of modern life, the IoT is all set to revolutionize the traveling sector by extending services associated with safety, security, surveillance, tracking, comfort, and a lot more. This paper presents the design and implementation of a prototype Easy-Weigh-Out, based on the principles of the IoT which enables a user to run Android-based mobile application and view the weight of luggage and track its location without any contact with it. The hardware of the system is built around Arduino UNO microcontroller which interfaces with a load cell (20 kg) via A/D converter and a NEO-6M Global Positioning System (GPS) module for tracking of the bag. The system uploads data to a Cloud server using ESP8266 Wi-Fi module. Our results show the real-time weight and tracking of the bag at a cl...
Mobile Ad-hoc Networks (MANETs) are infrastructure-less networks comprising of nodes that are mob... more Mobile Ad-hoc Networks (MANETs) are infrastructure-less networks comprising of nodes that are mobile and do not have fixed interconnections. These distinctive features render conventional routing algorithms unsuitable for these networks and designing special routing protocols for MANETs is an important area for ongoing research. Routing protocols that have been proposed till now can be categorized into three types, reactive, proactive and hybrid. This paper explicates and compares three significant routing protocols for MANETs, one from each category. We analyze these protocols in terms of end to end delay through simulations performed in Network Simulator (ns2) for varying network conditions like network load, mobility and network size. Our results show that none of the proposed protocols clearly outperforms others under all conditions. Although AODV and DSDV perform better when network congestion is less and TORA performs better for congested networks, there is a need to design a ...
Mobile ad hoc networks are envisaged to play a vital role in ubiquitous networking owing to their... more Mobile ad hoc networks are envisaged to play a vital role in ubiquitous networking owing to their mobility support without relying on infrastructure-based design. Conversely, the same feature makes routing in these networks challenging as compared to the typical wired networks. As a result typical routing protocols designed for wired networks are not appropriate for these networks. A number of routing protocols have emerged over the last few years which can be generally classified as proactive and reactive routing protocols. In this research, we analyze and compare three most important routing protocols from both categories in terms of throughput, end to end delay and packet delivery fraction. This comparison is useful in understanding the requirements and challenges for routing protocols in mobile and ad hoc setting and forms the basis of designing a new routing protocol which we plan to present in future. Our simulation results based on simulations carried out using Network Simula...
Engineering, Technology & Applied Science Research, 2018
Internet of Things (IoT) is expected to play a major role in our lives through pervasive systems ... more Internet of Things (IoT) is expected to play a major role in our lives through pervasive systems of sensor networks encompassing our environment. These systems are designed to monitor vital physical phenomena generating data which can be transmitted and saved at cloud from where this information can be accessed through applications and further actions can be taken. This paper presents the implementation and results of an environmental monitoring system which employs sensors for temperature and humidity of the surrounding area. This data can be used to trigger short term actions such as remotely controlling heating or cooling devices or long term statistics. The sensed data is uploaded to cloud storage and an Android application accesses the cloud and presents the results to the end users. The system employs Arduino UNO board, DHT11 sensor, ESP8266 Wi-Fi module, which transmits data to open IoT API service ThingSpeak where it is analyzed and stored. An Android application is develope...
The reliability of data transfer is vital for commercial and enterprise applications of Wireless ... more The reliability of data transfer is vital for commercial and enterprise applications of Wireless Sensor Networks (WSN). Likewise, mission-oriented and critical military applications of these networks demand dependable and timely data transport. This ...
A mobile ad hoc network is a collection of autonomous mobile nodes that communicate with each oth... more A mobile ad hoc network is a collection of autonomous mobile nodes that communicate with each other over wireless links. Such networks are expected to play an increasingly important role in future civilian and military settings, being useful for providing communication support where no fixed infrastructure exists or the deployment of a fixed infrastructure is not economically profitable and movement of communicating parties is possible. However, since there is no stationary infrastructure such as base stations, mobile hosts need to operate as routers in order to maintain the information about the network connectivity. Therefore, a number of routing protocols have been proposed for ad hoc wireless networks. In this paper, we study and compare the performance of the following routing protocols AODV, PAODV (preemptive AODV), CBRP, DSR, and DSDV. A variety of workload and scenarios, as characterized by mobility, load and size of the ad hoc network were simulated. Our results indicate that despite its improvement in reducing route request packets, CBRP has a higher overhead than DSR because of its periodic hello messages while AODV's end-to-end packet delay is the shortest when compared to DSR and CBRP. PAODV has shown little improvements over AODV.
A data center is a facility with a group of networked servers used by an organization for storage... more A data center is a facility with a group of networked servers used by an organization for storage, management and dissemination of its data. The increase in data center energy consumption over the past several years is staggering, therefore efforts are being initiated to achieve energy efficiency of various components of data centers. One of the main reasons data centers have high energy inefficiency is largely due to the fact that most organizations run their data centers at full capacity 24/7. This results into a number of servers and switches being underutilized or even unutilized, yet working and consuming electricity around the clock. In this paper, we present Adaptive TrimTree; a mechanism that employs a combination of resource consolidation, selective connectedness and energy proportional computing for optimizing energy consumption in a Data Center Network (DCN). Adaptive TrimTree adopts a simple traffic-and-topology-based heuristic to find a minimum power network subset called 'active network subset' that satisfies the existing network traffic conditions while switching off the residual unused network components. A 'passive network subset' is also identified for redundancy which consists of links and switches that can be required in future and this subset is toggled to sleep state. An energy proportional computing technique is applied to the active network subset for adapting link data rates to workload thus maximizing energy optimization. We have compared our proposed mechanism with fat-tree topology and ElasticTree; a scheme based on resource consolidation. Our simulation results show that our mechanism saves 50%-70% more energy as compared to fat-tree and 19.6% as compared to ElasticTree, with minimal impact on packet loss percentage and delay. Additionally, our mechanism copes better with traffic anomalies and surges due to passive network provision.
A data center is a facility that houses computational and storage systems which are interconnecte... more A data center is a facility that houses computational and storage systems which are interconnected through a communication network. Although the earlier data centers comprised of interconnected servers and related equipment, the hierarchical design of Abstract A data center is a facility for housing computational and storage systems interconnected through a communication network called data center network (DCN). Due to a tremendous growth in the computational power, storage capacity and the number of interconnected servers, the DCN faces challenges concerning efficiency, reliability and scalability. Although transmission control protocol (TCP) is a time-tested transport protocol in the Internet, DCN challenges such as inadequate buffer space in switches and bandwidth limitations have prompted the researchers to propose techniques to improve TCP performance or design new transport protocols for DCN. Data center TCP (DCTCP) emerge as one of the most promising solutions in this domain which employs the explicit congestion notification feature of TCP to enhance the TCP congestion control algorithm. While DCTCP has been analyzed for two-tier tree-based DCN topology for traffic between servers in the same rack which is common in cloud applications, it remains oblivious to the traffic patterns common in university and private enterprise networks which traverse the complete network interconnect spanning upper tier layers. We also recognize that DCTCP performance cannot remain unaffected by the underlying DCN architecture hence there is a need to test and compare DCTCP performance when implemented over diverse DCN architectures. Some of the most notable DCN architectures are the legacy three-tier, fat-tree, BCube, DCell, VL2, and CamCube. In this research, we simulate the two switch-centric DCN architectures; the widely deployed legacy three-tier architecture and the promising fat-tree architecture using network simulator and analyze the performance of DCTCP in terms of throughput and delay for realistic traffic patterns. We also examine how DCTCP prevents incast and outcast congestion when realistic DCN traffic patterns are employed in above mentioned topologies. Our results show that the underlying DCN architecture significantly impacts DCTCP performance. We find that DCTCP gives optimal performance in fat-tree topology and is most suitable for large networks.
The smart grid delivers electricity from suppliers to consumers and uses bidirectional communicat... more The smart grid delivers electricity from suppliers to consumers and uses bidirectional communication to exchange real-time information between supply system and smart meters at the user end. With a combined communication infrastructure, smart grid manages the operation of all associated components to provide reliable and supportable electricity supply. The Neighborhood Area Network (NAN) of smart grid supports bi-directional data transfer between smart meters (installed at customer premises) and control center of the utility company through an aggregator. This communication suffers low throughput and excessive delays due to the Head of Line (HOL) blocking when the Transmission Control Protocol (TCP) is implemented for reliability. In this paper we propose SCTP-aware Link Layer Retransmission mechanism (SCTP-LLR) which augments the Stream Control Transmission Protocol (SCTP) with Link Layer Retransmissions at the aggregator. SCTP-LLR uses the multi-streaming feature offered by SCTP a...
IEEE 802.15.4 based Wireless Personal Area Networks (WPANs) are envisioned to play a vital role i... more IEEE 802.15.4 based Wireless Personal Area Networks (WPANs) are envisioned to play a vital role in the application centric ubiquitous networks. In IEEE802.15.4 networks, the use of non-interfering logical channels in multiple PANs, operating in a Personal Operating Space (POS) ensures to control the scope of PAN-directed broadcasts, reduce received energy per PAN device, and minimize interference at the physical layer. At the downside the inter-PAN communication is not possible with this setup as PANs in the same region remain unaware of each other's presence. This situation hinders sharing information of common interest amongst PANs and accessing infrastructure networks hopping through multiple PANs. In this paper, we present a comprehensive architecture enables neighboring PANs to communicate by diffusing into each other through border nodes. The basic idea is to time share logical channels to perform a gating operation by border nodes. Our contribution includes detection of border nodes, discovery of neighboring PAN(s), a common channel based gating protocol, interest diffusion and inter-PAN data transfer. We mathematically analyze the proposed architecture and carry out simulations in Network Simulator (ns2) for performance evaluation. Our simulations show that the proposed architecture gives optimal performance when multiple border nodes are able to perform gating.
EURASIP Journal on Wireless Communications and Networking, 2013
Lately, wireless sensor network applications have emerged for provision of commercial services to... more Lately, wireless sensor network applications have emerged for provision of commercial services to end users. This results in commercial deployment of sensor networks which is as an important research area due to a number of design and quality of service challenges. An important technical challenge for sensor service provision to end users is managing dynamic network conditions such as unreliability of sensor nodes and network links which results in frequent service outages. This research is aimed at addressing this challenge. It presents a novel architecture which utilizes the availability of multiple sensor networks under different administrative domains, deployed in an area such that maximum network connectivity and high service availability are ensured. The architecture incorporates modifications and enhancements at the medium access control and the routing layers of sensor nodes for the collaborative operation of sensor networks. The design is based on IEEE 802.15.4 standard and...
EURASIP Journal on Image and Video Processing, 2014
Visual sensor networks (VSNs) are innovative networks founded on a broad range of areas such as n... more Visual sensor networks (VSNs) are innovative networks founded on a broad range of areas such as networking, imaging, and database systems. These networks demand well-defined architectures in terms of sensor nodes and camera deployment, image capturing and processing, and well-organized distributed systems. This makes existing VSN architectures deficient because these are limited in approach and in design. In this paper, we propose VISTA, a distributed vision multi-layer architecture aimed at constructing the cumulative vision of mobile objects (MOs). VISTA realizes silhouette recognition of mobile targets through (a) premeditated deployment of sensor nodes (SNs) that are equipped with sonar sensors and fixed view (FV) on-board cameras present at the periphery of region of interest (RoI) and SNs with only on-board cameras within RoI, (b) pre-distribution of silhouettes of known objects across SNs, (c) sonar-based presence detection of MO at the outskirts of RoI, (d) MO silhouette capturing and matching at interior node to determine the % age match, (e) subsequent activation of next interior cameras in order to improve % age match, and (f) terminating further activation upon threshold recognition of MO. Experimental evaluation of our image processing algorithms against baseline algorithms with respect to execution time and memory shows significant reduction in image data and memory occupancy. Also, experiments show that true match is achieved fully under broad daylight conditions and large backgrounds when our proposed background subtraction and pixel reduction techniques are used. The mobility-driven behavior of associated network layer algorithms of VISTA is simulated in a network simulator (NS2) by representing the surety of MO identification as a function of number of cameras, database size and distribution, MO's trajectory, stored perspectives, and network depth. The simulation results show that doubling and, in some situations, manifold increase is observed in the surety of the target with an increase in the number of silhouettes deployed against the baselined database size and mobility model. The results substantiate that VISTA is a suitable architecture for low-cost, autonomous and efficient human and asset monitoring surveillance, friend-or-foe (FoF) identification, and target tracking systems.
EURASIP Journal on Wireless Communications and Networking, 2010
6LoWPAN (IPv6 based Low-Power Personal Area Network) is a protocol specification that facilitates... more 6LoWPAN (IPv6 based Low-Power Personal Area Network) is a protocol specification that facilitates communication of IPv6 packets on top of IEEE 802.15.4 so that Internet and wireless sensor networks can be interconnected. This interconnection is especially required in commercial and enterprise applications of sensor networks where reliable and timely data transfers such as multiple code updates are needed from Internet nodes to sensor nodes. For this type of inbound traffic which is mostly bulk, TCP as transport layer protocol is essential, resulting in end-to-end TCP session through a default gateway. In this scenario, a single gateway tends to become the bottleneck because of non-uniform connectivity to all the sensor nodes besides being vulnerable to buffer overflow. We propose SET; a management architecture for multiple split-TCP sessions across a number of serving gateways. SET implements striping and multiple TCP session management through a shim at session layer. Through analytical modeling and ns2 simulations, we show that our proposed architecture optimizes communication for ingress bulk data transfer while providing associated load balancing services. We conclude that multiple split-TCP sessions managed in parallel across a number of gateways result in reduced latency for bulk data transfer and provide robustness against gateway failures.
Blockchain-based Internet of Things (BIoT) is an emerging paradigm of Internet of Things (IoT) wh... more Blockchain-based Internet of Things (BIoT) is an emerging paradigm of Internet of Things (IoT) which utilizes the blockchain technology to provide security services to the IoT applications. In essence, the blockchain built-in security mechanism can provide services such as availability, authentication, authorization, confidentiality, and integrity to the IoT applications. While most of the IoT devices are inherently resource-constrained in terms of computational power and storage capacity, the downside for blockchain is a requirement of massive amount of energy and computational resources for its operation, which poses challenges to the realization of BIoT. This paper strives to explore the challenges associated with the integration of blockchain and IoT and review their solutions. First, a brief introduction of blockchain technology is presented, followed by characterization of blockchain-based IoT applications as per their heterogeneous traffic demand and Quality of Service (QoS) requirements. Next, challenges that limit the design, development, and deployment of BIoT applications are explained in detail such as energy efficiency, privacy, throughput, latency, fork problem, security, legal issues, smart contracts, storage, and network broadcast mechanism and their proposed solutions are discussed. Finally, future research directions of blockchain and IoT integration are indicated. This investigation will benefit the researchers and developers to identify and solve blockchain and IoT integration challenges in order to realize efficient BIoT applications.
AbstractIEEE 802.15.4 Wireless Personal Area Networks (WPANs) are envisaged to play an important... more AbstractIEEE 802.15.4 Wireless Personal Area Networks (WPANs) are envisaged to play an important role in future ubiquitous network applications. When multiple PANs operate in the same area called personal operating space (POS), they are not aware of each other's presence ...
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