Faisal Bashir

Real life applicable fall detection system based on wireless body area network

Real-time health monitoring with wearable sensors is an active area of research. In this domain, observing the physical condition of elderly people or patients in personal environments such as home, office, and restroom has special significance because they might be unassisted in these locations. The elderly people have limited physical abilities and are more vulnerable to serious physical damages even with small accidents, e.g. fall. The falls are unpredictable and unavoidable. In case of a fall, early detection and prompt notification to emergency services is essential for quick recovery. However, the existing fall detection devices are bulky and uncomfortable to wear. Also, detection system using the devices requires the higher computation overhead to detect falls from activities of daily living (ADL). In this paper, we propose a new fall detection system using one sensor node which can be worn as a necklace to provide both the comfortable wearing and low computation overhead. The proposed necklace-shaped sensor node includes tri-axial accelerometer and gyroscope sensors to classify the behaviour and posture of the detection subject. The simulated experimental results performed 5 fall scenarios 50 times by 5 persons show that our proposed detection approach can successfully distinguish between ADL and fall, with sensitivities greater than 80% and specificities of 100%.

A hybrid routing protocol for wireless sensor networks with mobile sinks

Low power and lossy networks have been an active area of research due to their large number of potential applications in different environments like health, environment monitoring and entertainment domain. Numbers of protocols have been proposed for routing in these networks using metrics like hop count, delay, bandwidth etc. The working group of IETF has done one major contribution in form of a proactive gradient based routing protocol for low power and lossy networks (RPL). However, for a network having few mobile sinks calculating gradients using proactive approach is costly in terms of energy. This paper proposes a hybrid routing protocol for wireless sensor networks with mobile sinks. It proposes a combination of reactive and proactive approach to enhance RPL for efficiently handling movement of multiple sinks. DAGs are only maintained by nodes close to the sink within a certain zone. While the nodes outside the zone use on demand sink discovery to find the closest possible sink, without maintaining DAG. The frequency of zone creation messages and zone sizes can increase or decrease depending on the speed of sink. This helps to decrease the number of retransmissions resulting in low standing cost for maintain DAGs and enhances the network life time especially under average or high mobility of sink.

Dual head clustering scheme in wireless sensor networks

Energy efficient data aggregation is one of the key research areas of wireless sensor networks (WSNs). Many clustering techniques have been proposed for topology maintenance and routing in these networks. In addition to this, these techniques are also beneficial in prolonging the network life time. Clustering protocols proposed in existing literature use a single Cluster Head (CH) for a group of nodes (Cluster). In these protocols, the CH performs a number of activities, such as data gathering, data aggregation and data forwarding. As a result, the CH depletes its energy quickly as compared to its member nodes. Hence, re-clustering is required frequently, which consumes considerable energy. This paper proposes an energy efficient Dual Head Clustering Scheme (DHCS) for WSNs. DHCS selects two different nodes within the cluster for cluster management and aggregation namely Cluster Head (CH) and Aggregator Head (AH) respectively. Simulation results show that the DHCS outperforms conventional clustering protocols in terms of energy conservation, network life time and network latency.

XL-WMSN: cross-layer quality of service protocol for wireless multimedia sensor networks

Energy conservation has been the prime motivation behind the design of conventional protocols for wireless sensor networks (WSNs). However, recent trends toward high data rate multimedia communication over WSNs demand traffic- and deadline-aware content delivery with minimum energy expenditure. The basic quality of service requirement in wireless multimedia sensor networks (WMSNs) is time-bound data delivery. The conventional-layered protocol design solutions are inefficient, as real-time content delivery requires interactions between multiple layers like application for traffic categorization, network for real-time delivery, and media access control (MAC) for prioritized medium access with minimum energy expenditure. In this paper a cross-layer solution (XL-WMSN) is proposed for real-time data delivery. The XL-WMSN provides interaction between energy-based admission control, delay- and interference-aware routing, and dynamic duty cycle assignment at MAC layer. Simulation analysis shows that XL-WMSN increases the probability of delivering multimedia content within their allocated deadline and is more efficient than existing solutions.

Coordinator assisted passive discovery for mobile end devices in IEEE 802.15.4

Energy conservation has been the key focus of research in low-rate wireless personal area networks (WPANs). Several algorithms have been proposed to dynamically adjust the duty cycle of nodes in beacon-enabled WPANs. Increasing beacon interval for lowering the duty cycle of end devices decreases the probability of fast node association, when passive scan is used. Moreover, the requirement of performing coordinator discovery increases with mobility of end devices because of frequent cell changes. In this paper, we propose a scheme for facilitating prompt passive discovery of coordinator(s) by mobile end devices. Simulation analysis has shown that proposed scheme can swiftly discover the coordinator(s) irrespective of beacon interval length.

Cross -layer QoS routing protocol for Multimedia communications in Sensor Networks

Wireless Multimedia Sensor Networks (WMSN) are new and emerging networks of wirelessly connected devices, which consist of cameras, microphones, infra-red sensors, scalar sensors and others. These networks are fast gaining popularity due to their potential to be incorporated in various applications, such as, traffic monitoring, border surveillance, smart homes, environment and habitat monitoring, to retrieve heterogeneous data from the environment. However, these networks present many challenges as they are highly sensitive to delay and errors. The paper presents a Cross-layer QoS Routing protocol for WMSNs (CR-WMSN) that is aimed at providing soft end-to-end delay guarantees. Evaluation of this protocol shows that it provides better delay guarantees as compared to minimum hop routing protocol.

Intelligent routing protocol for Multimedia Sensor networks

The increase in the usefulness of WSNs, have lead to the transmission of multimedia content over these networks. This has escorted to the concept of Wireless Multimedia Sensor networks (WMSNs). Due to resource constrained structure of WSNs, special attention is required to route data in these networks. In this paper, we propose a novel routing protocol for WMSNs which establishes paths on the basis of traffic load, hop count and node energy. The protocol aims to find completely or partially disjoint paths for routing multimedia traffic with relatively minimum distance. Simulation results have shown that the proposed protocol is capable of finding intelligent path such that it increases throughput and avoid creation of network holes near the sink.

Comparative study of centralized cooperative spectrum sensing in cognitive radio networks

Fixed spectrum assignment policy is loosing applicability in present wireless networks which demand for efficient usage of spectrum. There is an urgent need to fully exploit the available spectrum. Moreover, regulatory bodies require flexible and adaptable band assignment techniques to tackle for inefficient utilization of spectrum. Cognitive radio (CR) network is a key solution used by organizations to counter the short comings of fixed spectrum assignment policy. This paper analyzes different centralized cooperative spectrum sensing techniques to detect the Primary Transmitter (PT) in wireless band. Techniques compared in this study include fuzzy logic collaborative sensing, asynchronous cooperative sensing, weighted cooperative sensing etc. Conclusive analysis of this paper indicates that probability of detection can be best achieved by sending local decision of CR user to decision center (DC), which further confirm it on the bases of collaborative decision about the existence of PT.

A hash-based distributed mapping control scheme in mobile locator-identifier separation protocol networks

Summary In the locator-identifier separation protocol (LISP), the existing mapping control scheme is based on a centralized approach, in which a map server is used as a mobility anchor for mobile hosts. However, such a centralized scheme has some limitations that include traffic overhead at the central map server, service degradation by a single point of failure, and large data transmission delay. In this article, we propose a new hash-based distributed mapping control scheme of endpoint identifier (EID) and local locator in the LISP-based mobile networks. In the proposed scheme, each access router in the mobile network has a distributed local map server. For a mobile host, a distributed local map server is designated to manage the associated EID-local locator mapping by using a hash function. For roaming support, each gateway has a distributed global map server, which maintains visiting EID-locator register. From the numerical results, we see that the proposed scheme can reduce the amount of control traffic at the map server and total signaling delay compared to the existing mapping control schemes.

Cluster-based data dissemination, cluster head formation under sparse, and dense traffic conditions for vehicular ad hoc networks

Information and communication technologies have changed the way of operations in all fields. These technologies also have adopted for wireless communication and provide low cost and convenient solutions. Vehicular ad hoc networks are envisioned with their special and unique intercommunication systems to provide safety in intelligent transportation systems and support large-size networks. Due to dense and sparse traffic conditions, routing is always a challenging task to establish reliable and effective communication among vehicle nodes in the highly transportable environment. Several types of routing protocols have been proposed to handle high mobility and dynamic topologies including topology-based routing, position and geocast routing, and cluster-based routing protocols. Cluster-based routing is one of the feasible solutions for vehicular networks due to its manageable and more viable nature. In cluster-based protocols, the network is divided into many clusters and each cluster selects a cluster head for data dissemination. In this study, we investigate the current routing challenges and trend of cluster-based routing protocols. In addition, we also proposed a Cluster-based Routing for Sparse and Dense Networks to handle dynamic topologies, the high-mobility of vehicle nodes. Simulation results show a significant performance improvement of the proposed protocol.