Jemimah Ebenezer

Low latency and energy efficient routing protocols for wireless sensor networks

Wireless sensor network (WSN) consists of tiny sensor nodes with sensing, computation and wireless communication capabilities. Now a days, it is finding wide applicability and increasing deployment, as it enables reliable monitoring and analysis of environment. The design of routing protocols for WSN is influenced by many challenging factors like fault tolerance, energy efficiency, scalability, latency, power consumption and network topology. In this paper, we mainly focus on minimizing end to end latency and energy efficiency as primary design objectives of routing protocols for WSN without overshadowing the other design factors. We present a survey of low latency, energy efficient and time critical routing protocols. TEEN (Threshold - sensitive Energy Efficient sensor Network protocol), a reactive network protocol which is well suited for time critical data sensing applications is quite efficient in terms of energy consumption and response time. APTEEN (Adaptive Periodic Threshold - sensitive Energy Efficient sensor Network protocol), a hybrid network protocol which gives the overall picture of the network at periodic intervals in a very energy efficient manner. SPEED is a Stateless, highly efficient and scalable protocol for sensor networks which achieves end to end soft real time communication by maintaining a desired delivery speed across the network through a novel combination of feedback control and non deterministic geographic forwarding. RAP, a real - time communication architecture for large scale sensor networks which significantly reduces the end to end latency by using Velocity - Monotonic Scheduling (VMS). RPAR, Real - Time Power Aware Routing Protocol which supports energy efficient real - time communication by dynamically adapting transmission power and routing decisions. We also discuss the advantages and performance issues of each routing protocol.

Experimental analysis of RSSI for distance and position estimation

In wireless sensor network (WSN), position awareness (localization) of the sensor nodes is necessary to exploit the communication and to provide the meaningful information about their surroundings. Here Received Signal Strength Indicator (RSSI) technique is used as it requires no extra hardware and can be used for both indoor and outdoor environment. RSSI is having limitations such as high randomness due to fading and shadowing. This makes difficulties in establishing exact relationship between RSSI value and distance. In this paper we propose the method of creating database by using Split Range Technique (SRT) to estimate the approximate distance between two nodes. Using this database, position estimation has been done. For this Adaptive n-Triangle algorithm is implemented. Present results of RSSI shows the approximate positioning of the sensor node with the error estimation of about 5–10%. The experiment can be extended to show the predicted path of a moving object which is being identified by sensors.

WSN based temperature monitoring for High Performance Computing cluster

Wireless Sensor Network (WSN) supports different kinds of applications in distinct areas, such as military, health care, agriculture, home or industry automation and others. Generally, there are three models of WSN: continuous, on-demand and event-driven. In continuous model, sensors send data periodically to the sink. In on-demand model, sensors sense continuously, store the data and sends only when requested. In event driven model the sensors send data only when certain events occur. In this paper we have presented the implementation details of WSN based temperature monitoring application. The main feature of our network is to continuously monitor the temperature in the 128 node High Performance Computing Cluster for its smooth functioning. The wireless sensor node senses and transmits the current value of temperature to the base station. This paper explains about the various steps involved in the experimental implementation and maintenance of the temperature monitoring network for High Performance Computing cluster at Computer centre, IGCAR. The performance analysis of the network is also discussed.

Theoretical analysis on designing Full Functional Device of WSN using Wireless Power Transfer

Wireless Sensor Network (WSN) is not completely autonomous and wire free, as Full Functional Devices (FFD), that are part of the network, require continuous power source (AC mains). The main aim of this paper is to make WSN completely wire free, fully autonomous and self sustainable system. This paper analyzes the feasibility of removing the power line (wired) connection for FFD of WSN. Theoretical calculation and analysis to design a low power FFD with good processing speed has been performed. The designed node can continuously operate in active mode on battery for 8 days (generally FFD will be always active). To make the device functional for longer duration energy harvesting (EH) solutions has been considered. Initially, solar was found to be the only such EH source. Later, Wireless Power Transfer (WPT) possibilities for WSN node has been analyzed, as solar power is available only for outdoor environment. Thus by EH solutions like solar along with WPT, power wire of a low power FFD can be eliminated.

Ethernet gateway for wireless sensor networks

In any industrial environment, the plant data network is used to connect instruments and systems distributed across entire plant area. It allows central monitoring and control of the instruments very easy. With the advent of wireless sensor networking technology, few industries started adapting the wireless monitoring systems in phases. Gateway devices allow data communication between main plant data network and wireless field devices. It enables application level access to these field devices from central monitoring station. The gateways devices are used as protocol converter, command/data forwarder and also it can be used as Security Manager, Synchronizer in network. In this implementation, the Ethernet gateway has been designed to collect data from wireless sensor network and connect to the existing Ethernet network. This paper describes the design and development of Ethernet gateway and also describes the integration of this gateway with the computer centre wireless sensor network.

Development of network debugging tools for IEEE 802.15.4 networks

Different commercial Wireless Sensor networking systems use IEEE 802.15.4 as a basis for their media access control mechanisms. IEEE 802.15.4 is a physical and media access layer standard for low rate WPANs (LR-WPAN). Various experimental Wireless Sensor Networks have been deployed in IGCAR with the different type of sensors. WSN Network monitoring and analyzer tools are useful during the software development phase to assist in network design and during deployment phase for assessment of RF environment and traffic analysis. During various development and deployment experiments, we have developed different network debugging and analyzer tools. In this paper, the hardware and software details of these tools have been presented along with implementation specifics. These tools were used during site survey assessment phase and were found very useful. Application specific uses are also described in this paper.

EMI/EMC testing of wireless sensor networking node

For the deployment of Wireless Sensor Networks (WSN) in nuclear reactor environment to monitor and measure the plant parameters, the WSN nodes should be rugged, able to withstand high temperature, radiation and should be qualified in the environmental tests, Electromagnetic compatibility (EMC) and seismic tests as per the international standards. Hence Industrial grade wireless sensor networking nodes which meet the required specifications have been designed and developed. The nodes after successful development and functionality testing have been subjected to EMC tests at EMI/EMC Lab in Indira Gandhi Centre for Atomic Research (IGCAR). Subsequently they have been successfully qualified for EMC tests at SAMEER (Society for Applied Microwave Electronic Engineering and Research), chennai. This paper describes briefly about the design and development of nodes, measures taken for EMC qualification of nodes, qualification tests done and the test results.