Categories for The MAC Protocols for Wireless Sensor Networks

A WSN is a type of wireless networks that consists of collection sensor nodes which are tiny devices. Each sensor node of the network has different processing capability. It may contain multiple types of memory (program, data and flash memories), have a RF transceiver, have a power source (e.g., batteries and solar cells), and accommodate various sensors and actuators. The nodes communicate wirelessly and often self-organize after being deployed in an ad hoc fashion [13, 14]. Optimum need of each sensor node is to maximize its own utility function. Also the whole network requires resource assignments balance to perform in a useful and efficient way. This chapter presents a brief survey on WSNs showing its types, characterizing features, protocols and applications.

At the beginning of first period, each node except the sink node sets its both cost fields to and parent node fields to -1, but at the beginning of subsequent periods, each node only sets its both cost field to and no change is made to the parent node fields. The sink node sets its both cost fields to 0 and set its parent node fields to its own ID. At the beginning of this phase, sink node transmit an ADV1 message to all its neighbours. When a node receives an ADV1 message, it does not broadcast its own ADV message to its neighbour immediately. Following steps are executed before sending the ADV1 message to its

Dense Traffic:Nodes Simply broadcasting the packets leads to many collisions and conflicts in transmission among neighbouring nodes.

From the past years, there has been a rapid growth in the field of wireless communication for the need of connectivity. The main reason behind this growth is excessive data exchange rate through wireless data networks such as internet services, telephones, etc. The quality of service and throughput of these wireless networks has got very strong impact on man’s day to day life. Two of those most important wireless networks which are universally used today are Ad Hoc and Sensor Networks. Ad-hoc networks are infrastructure less and self-adaptable wireless networks. In this networks no node is an access point and Sensor networks is more or less considered as an Ad

Data communication allows individuals and companies to transmit or receive information from one point to another. For two or more devices to communicate, there should be some mechanism or medium that can link them to help them achieve their goals. This mechanism or medium is governed by rules or laws defining a format is called a protocol [3]. This is because all communications between devices require that the devices agree on proper format of the data. There are variety of standard protocols from which programmers can choose based on the resources available and mainly on the requirements. For e.g. if reliability is very important, then reliable protocols such as TCP should be used. Each protocol has its own advantage and restrictions. Depending on several factors such as speed, reliability, simplicity, programmers choose these protocols. In this essay, I am going to address about the networks and commonly used protocols, functions of seven layers of the OSI model, TCP/IP protocol, and protocols used in wireless communication.

Domestic Applications: Sensor networks can bring the idea of smart homes where we can monitor and control at site or remotely home appliances like air conditioning, heating, ventilation, refrigeration, security alarms etc.

Keywords—wireless sensor network, distributed wireless sensor network, hierarchical wireless sensor network, key distribution, key pre-distribution, pair-wise keys, group-wise key, network keying.

detected by all nodes but are accepted only by the node(s) to which they are

Published schemes on tolerating node failure can be classified into two categories; provisioned and reactive solutions. Provisioned tolerance relies on the availability of redundant resources that can make up for the lost node(s). However, provisioned solutions for restoring connectivity are not suitable for WSAN since actors are typically more expensive and hard to deploy compared to sensors and thus assuming the presence of many actors is not practical. The second category pursues real-time restoration of severed connectivity. The main idea is to reposition the healthy actors so that a strongly connected inter-actor network topology can be established. For example, DARA [2] replaces the failed node with one of its neighbours. The approach requires every node to maintain 2-hop neighbour information so that the effect of the loss of a node can be assessed, i.e., whether the failed node is highly probable a cut-vertex or not. The candidate among the neighbours of the failed node is picked based on the node degree, distance from the failed node and the nodes ID respectively. The effect of moving a node triggers a cascaded relocation that ripples throughout the network to avoid breaking connectivity in another part in the network. The approach of [5] strives to limit the scope of cascaded relocation through the identification of dominators.

The B-MAC is proposed to meet these goals, a configurable MAC protocol for WSNs. It is simple in both for implementation and design. MAC protocol support a wide variety of sensor network workloads by factoring out some functionality and exposing control to higher services. In contrast to the classic monolithic MAC protocol this minimalist model of MAC protocol is designed [1].

A Wireless Sensor Network (WSN) has a large number of energy constrained sensor nodes that have the capability to compute and communicate. They are used to identify the events of interests and transfer the data to the sink node.

Energy efficient routing algorithm can be categorized as follows: data centric routing algorithm, location based routing algorithm and hierarchical routing algorithm . Data centric routing algorithm uses meta data to find the route from source to destination before any actual data transmission to eliminate redundant data transmission Location based routing algorithm requires actual location information for every sensor node. Hierarchical routing algorithm divides the network into clusters. Cluster head (CH) is elected in

When a sensor node has new data, it advertises it using the ADV messages to its neighbors. When a neighboring node receives this message, it checks whether it has already received or requested the advertised data. If not, it sends an REQ message back to the broadcast address requesting the data item. Upon receiving a REQ message, only the originating node sends the actual data to the requesting nodes. One advantage of this protocol is its simplicity and does not require any other topology information.

Wireless sensor networks are the networks that gather information such as environmental information, which there are numbers of applications of WSN such as healthcare, building monitoring, forest fire, smart home etc. WSN is capable of sensing, processing and communicating independently. However, as most of the sensor nodes are powered by non-rechargeable battery, the limitation of energy supply has considerably reduced the lifetime of the sensor network. Hence, new designs of sensor node network and energy efficient MAC (Media Access Control) and protocols for long term autonomous monitoring wireless sensor network has become the next vision.

Low Energy adjustive clump Hierarchy(LEACH) protocol [2],[ 3] is class-conscious protocols during which cluster heads are at random elective . The operation in LEACH consists of the set-up part and steady state part. The set-up state part contains of cluster heads (CHs) choice and cluster formation.The steady state part contains of sensing and transmission of the perceived data to the bottom station &(BS) through CHs. In each spherical, at the beginning the set-up part, every sensing element node generates a random range between zero and one to choose whether or not it will become a CH or not for the present spherical. If the quantity generated by sensing element node is a smaller amount than the edge price