TEEN: A Routing Protocol for Enhanced Efficiency in Wireless Sensor Networks. By M. JAFFAR KHAN SP11-REE-029. Abstract. Classification of sensor networks with respect to mode of functioning proactive networks reactive networks - PowerPoint PPT Presentation
TEEN: A Routing Protocol for Enhanced Efficiency in Wireless Sensor Networks
TEEN: A Routing Protocol for Enhanced Efficiency in Wireless Sensor NetworksBy M. JAFFAR KHANSP11-REE-0291AbstractClassification of sensor networks with respect to mode of functioningproactive networksreactive networks Proactive networks, respond immediately to changes in the relevant parameters of interest. TEEN (Threshold sensitive Energy Efficient sensor Network protocol) is for reactive networks. Teen protocol is for a simple temperature sensing applications. Energy efficient protocol than conventional sensor network protocols.2Requirements of Sensor NetworksSensor networks are usually unattended and need to be fault-tolerantThe advancement in technology extremely smallLow powered devices equipped with programmable computingmultiple parameter sensing wireless communication capability. low cost of sensors makes network of huge amount of wireless sensors,enhancing the reliability and accuracy of data and the area coverage sensors be easy to deploy (i.e., require no installation cost etc). Protocols for these networks must be designed in such a way that the limited power in the sensor nodes is efficiently used. Environments in which these nodes operate and respond are very dynamic, with fast changing physical parameters.3Requirements of Sensor Networks(Cont)Depending on the application, following parameters may change dynamically :Power availability.Position (if the nodes are mobile).Reachability.Type of task (i.e. attributes the nodes need to operate on)So, the routing protocol should be fault-tolerant in such a dynamic environment.4
Requirements of Sensor Networks(Cont)
Sensor networks are data centric unlike traditional networks where data is requested from a specific node, data is requested based on certain attributes such as, which area has temperature 50 F ?
Sensor Network is application-specific. The requirements of the network change with the applicationFor example, in some applications the sensor nodes are fixed and not mobile, while others need data based only on one attribute (i.e., attribute is fixed in this network).
5In both cases we assume there are some common elements- the sink first sends out a query/interest for data, the sensor nodes which have the appropriate data then respond with the data. They differ in the manner the data is sent from the sources to the sink:Data-centric Protocol (DC): The sources send data to the sink, but routing nodes enroute look at the content of the data and performsome form of aggregation/consolidation function on the data originating at multiple sources.Figure is a simple illustration of the difference between AC and DC schemes. In the address-centric approach, each source sends its information separately to the sink (source 1 routing the data labelled 1 through node A, and source 2 routing the data labelled 2 through nodes C and B). In the data centric-approach, the data from the two sources is aggregated at node B, and the combined data (labelled 1+2) is sent from B to the sink. This results in energy savings as fewer transmissions are required to send the information from both sources to the sink.5Requirements of Sensor Networks(Cont)Adjacent nodes may have similar data. So, rather than sending data separately from each node to the requesting node, desirable to aggregate similar data and send it.In traditional wired and wireless networks, each node is given a unique id, used for routing. This cannot be effectively used in sensor networks. This is because, these networks being data centric, routing to and from specific nodes is not required. Also, the large number of nodes in the network implies large ids , which might be substantially larger than the actual data being transmitted.
Thus, sensor networks need protocols which are application specific, data centric, capable of aggregating data and optimizing energy consumption.6An ideal sensor network should have the following additional features:Attribute based addressing The attribute based addresses are composed of a series of attribute-value pairs which specify certain physical parameters to be sensed. For example, an attribute address may be (temperature 100 F, location=??) So, All nodes which sense a temperature greater than 100 should respond with their location.Location awareness. Since most data collection is based on location, it is desirable that the nodes know their position whenever needed.7 Related WorkProvide a brief overview of some related research work. Intanagonwiwat et. al have introduced a data dissemination paradigm called directed diffusion for sensor networks.It is a data-centric paradigm and its application to query dissemination and processing has been demonstrated in this work.Estrin et. al discuss a hierarchical clustering method with emphasis on localized behavior and the need for asymmetric communication and energy conservation in sensor networks.83.3.3 Query-based:In this type of routing protocols the base station sends queries for requesting data from the targeted node. A node that sense or collect data, read the query and if there is matched data it will forward it to the base station or any mentioned sink. This process is also known as Directed Diffusion .In Directed Diffusion base station sends an interest message to the network, it spreads across the network through moving in the nodes. If a node is having data suitable to the interest message, will send it back on the path on which it received the interest message. Data aggregation is performed on data while it is moving from node to base station.3.7 Directed Diffusion: Directed Diffusion  is a well known flat routing protocol and many other protocols based on it. This protocol is of data centric nature, in which queries are directed to a certain area of the network instead of whole network. The Directed Diffusion protocol is completed in three steps namely interest propagation, gradient setup and data delivery. In interest propagation, a node spread an attribute along with a certain value for example an attribute is temperature and value is set to 35. This named data might be for all nodes that have an attribute temperature and a value (>35). This named data has the advantage of receiving only the interested data. The initial interest also specifies the rate at which the node has to send data to the sink that might be ten seconds or so. The initial interest also specifies the time stamp value i.e. when to stop sending data. It might be 10 minutes or so. The interest entry contains the ID of nodes from which interest has received. It also defines the data rate to be used for communication with those nodes. Second stage is gradient setup; gradient is the data rate at which to send data about a specific interest to a specific neighbor. Directed Diffusion also uses data aggregation in which the received data is compared with the data in node cache and duplication is discarded. During the last stage of data delivery, data is forwarded to the sink. Data is sent with a data rate specified in the reinforcement message. The data is sent via a single path that was established.
8Related Work(Cont)A cluster based routing protocol (CBRP) has been proposed by Jiang et. al in for mobile ad-hoc networks. It divides the network nodes into a number of overlapping or disjoint two-hop-diameter clusters in a distributed manner. this protocol is not suitable for energy constrained sensor networks in this form. Heinzelman et. al introduce a hierarchical clustering algorithm for sensor networks, called LEACH.9 MotivationIn the current body of research done in the area of wireless sensor networks, we see that particular attention has not been given to the time criticality of the target applications. Most current protocols assume a sensor network collecting data periodically from its environment or responding to a particular query. We feel that there exists a need for networks geared towards responding immediately to changes in the sensed attributes. We also believe that sensor networks should provide the end user with the ability to control the trade-off between energy efficiency, accuracy and response times dynamically. So, in our research, focused on developing a communication protocol which can fulfill these requirements.10Classification of Sensor NetworksClassification of sensor networks on the basis of their mode of functioning and the type of target application. Proactive Networksnodes in the network periodically switch on their sensors and transmitters, sense the environment and transmit the data of interest.Reactive Networksnodes react immediately to sudden and drastic changes in the value of the sensed attribute.well suited for time critical applications.11Sensor Network ModelBased on the model developed by Heinzelman et. al. (leach paper), We consider a model which is well suited for these sensor networks,consists of a base station (BS), away from the nodes, through which the end user can access data from the sensor network.homogeneous and begin with the same initial energy.The BS however has a constant power supply and so, has no energy constraints. BS can transmit with high power to all the nodes. Thus, there is no need for routing from the BS to any specific node. the nodes cannot always reply to the BS directly due to their power constraints, resulting in asymmetric communication.12Multi-Level Hierarchical ClusteringEach cluster has a cluster head which collects data from its cluster members, aggregates it and sends it to the BS or an upper level cluster head. For example, nodes 1.1.1, 1.1.2, 1.1.3, 1.1.4, 1.1.5 and 1.1 form a cluster with node 1.1 as the cluster head. Similarly there exist other cluster heads such as 1.2, 1 etc. These cluster-heads, in turn, form a cluster with node 1 as their second level cluster-head. This pattern is repeated to form a hierarchy of clusters with th