Improvement of Quality of Service Parameters in Dynamic and Heterogeneous WBAN

With growth in population and diseases, there is a need for monitoring and curing of patients with low cost for various health issues. Due to life threatening conditions, loss-free and timely sending of data is an essential factor for healthcare WBAN. Health data needs to transmit through reliable connection and with minimum delay, but designing a reliable, and congestion and delay free transport protocol is a challenging area in Wireless Body Area Networks (WBANs). Generally, transport layer is responsible for congestion control and reliable packet delivery. Congestion is a critical issue in the healthcare system. It not only increases loss and delay ratio but also raise a number of retransmissions and packet drop rates, which hampers Quality of Service (QoS). Thus, to meet the QoS requirements of healthcare WBANs, a reliable and fair transport protocol is mandatory. This motivates us to design a new protocol, which provides loss, delay and congestion free transmission of heterogeneous data. In this paper, we present a Dynamic priority based Quality of Service management protocol which not only controls the congestion in the network but also provides a reliable transmission with timely delivery of the packet

PFPS: Priority-First Packet Scheduler for IEEE 802.15.4 Heterogeneous Wireless Sensor Networks

This paper presents priority-first packet scheduling approach for heterogeneous traffic flows in low data rate heterogeneous wireless sensor networks (HWSNs). A delay sensitive or emergency event occurrence demands the data delivery on the priority basis over regular monitoring sensing applications. In addition, handling sudden multi-event data and achieving their reliability requirements distinctly becomes the challenge and necessity in the critical situations. To address this problem, this paper presents distributed approach of managing data transmission for simultaneous traffic flows over multi-hop topology, which reduces the load of a sink node; and helps to make a life of the network prolong. For this reason, heterogeneous traffic flows algorithm (CHTF) algorithm classifies the each incoming packets either from source nodes or downstream hop node based on the packet priority and stores them into the respective queues. The PFPS-EDF and PFPS-FCFS algorithms present scheduling for each data packets using priority weight. Furthermore, reporting rate is timely updated based on the queue level considering their fairness index and processing rate. The reported work in this paper is validated in ns2 (ns2.32 allinone) simulator by putting the network into each distinct cases for validation of presented work and real time TestBed. The protocol evaluation presents that the distributed queue-based PFPS scheduling mechanism works efficiently using CSMA/CA MAC protocol of the IEEE 802.15.4 sensor networks

VSRS: Variable Service Rate Scheduler for Low Rate Wireless Sensor Networks

This paper proposes a variable service rate scheduler VSRS for heterogeneous wireless sensor and actuator networks (WSANs). Due to recent advancement, various applications are being upgraded using sensor networks. Generally, traffic consists of delay sensitive and delay tolerant applications. Handling such traffic simultaneously is a critical challenge in IEEE 802.15.4 sensor network. However, the standard CSMA/CA does not focus on traffic-based data delivery. Therefore, this paper presents a solution for prioritybased traffic over no-priority i.e. regular traffic using CSMA/CA IEEE 802.15.4 MAC sublayer. The VSRS scheduler uses a queuing model for scheduling incoming traffic at an actor node using a dual queue. The scheduler updates priority of each incoming packet dynamically using network priority weight metric. The VSRS scheduler scans queues and picks the highest network priority packet. A packet weight is updated after selection from the respective queue. This core operation of an actor node offers good packet delivery ratio, throughput, and less delay experience of long distance traveled packets against no priority traffic. The work is validated using theoretical analysis and computer generated network simulators; proves that the priority based approach using weight factor works better over the First-Come-First-Serve (FCFS) mechanism

A Data Transmission Protocol for Wireless Sensor Networks: A Priority Approach

Recent development in the field of a wireless sensor network has shown the significant improvement and has emerged as a new energy efficient wireless technology for low data rate applications. Handling different types of event data altogether is a crucial task in the sensor networks. This paper presents the solution to the problem of heterogeneous data transmission of long distance prioritised nodes in low data rate wireless sensor networks (LR-WSNs). The solution comprises three main algorithms, namely data reporting, traffic scheduling, and centralised reporting rate mechanism. The data reporting algorithm reports the demanded data in each specified decision window size with variable reporting rate. The traffic aware packet scheduling algorithm performs the packet reprioritisation and scheduling. The priority assignment is designed based on the data priority and hop count. It serves transient traffic against newly sensed packets, or less hop distance travelled packets. As a result, it minimises the chances of dying earlier than its deadline. The third algorithm presents the flexible data gathering approach based on the level of the buffer either sensed by its own or recently received information from hop node. It uses a decision interval window for managing the frequency of data delivery. This centralised decision approach makes the sink node more adaptive for data gathering and controlling the active source nodes. This multi-tier framework functions over CSMA/CA due to its unique feature of energy saving, especially for LR-WSNs. The reported work is simulated and examined over various scenarios in the multi-hop wireless sensor networks. Moreover, the performance of the scheduler proves better data transmission rate for prioritybased traffic over regular traffic flows; approximately 7% over First-Come-First-Served (FCFS) and 5% against Precedence Control Scheme (PCS) mechanism using theoretical analysis and computer simulations

A priority-based energy efficient multi-hop routing protocol with congestion control for wireless body area network

Wireless Body Area Networks (WBANs) are advanced and integrated monitoring networks for healthcare applications. In these networks, different types of Biomedical Sensor Nodes (BSNs) are used to monitor physiological parameters of the human body. The BSNs have limited resources such as energy, memory and computation power. These limited resources make the network challenging especially in terms of energy consumption. Efficient routing schemes are required to save the energy during communication processes. Additionally, the BSNs generate sensitive and non-sensitive data packets, which need to be routed according to their priority. In order to address these problems, a priority-based Energy Efficient Multihop Routing protocol with congestion control (3EMR) for wireless body area network was developed that comprises of three different schemes. First, an Optimal Next-hop Selection (ONS) scheme was developed based on the cost function of routing parameters to dynamically select best next-hop for forwarding data packets. Second, a Priority Based Routing (PBR) scheme was developed to forward data packets according to data priority, which is based on sensitivity of the data with regards to patience’s life. Third, a Congestion Avoidance and Mitigation (CAM) scheme was developed to save energy consumption and packet loss due to congestion by considering packet flow adjustment and congestion zone avoidance based strategy. It improvement is benchmarked against related solutions, and they are Healthcare-aware Optimized Congestion Avoidance (HOCA), Differentiated Rate control for Congestion (DRC), Priority based Cross Layer Routing (PCLR), Even Energy-consumption and Backside Routing (EEBR), and Energy Efficient Routing (EER) scheme. The simulation results demonstrated that the 3EMR scheme achieved significant improvement in terms of increased network lifetime by 31.4%, increased throughput by 33.2%, reduced packet loss 30.9%, increased packet delivery ratio by 21.1% and reduced energy consumption 26.8%. Thus, the proposed routing scheme has proven to be an energy efficient solution for data communication in wireless body area networks

Congestion control mechanism for sensor-cloud Infrastructure

 This thesis has developed a sensor-Cloud system that integrates WBANs with Cloud computing to enable real-time sensor data collection, storage, processing, sharing and management. As the main contribution of this study, a congestion detection and control protocol is proposed to ensure acceptable data flows are maintained during the network lifetime