Mobile Multi-hop Data Gathering Mechanisms in WSN Networks Essay

The Two-Tier Data Dissemination (TTDD) assumes that the sensor nodes are stationary and location aware and sinks are allowed to change their location dynamically [9]. When any change is sensed by sensors the source node will generate the reports. Then the source node chooses itself as a start crossing point and sends data to its adjacent crossing points. This is also used in which nodes are stationery for multiple mobile sinks.

A group of wireless sensor nodes (devices) dynamically constructs a temporary network without the exercise of any pre-existing network infrastructure or centralized administration. The main goal of ad-hoc networking is multihop broadcasting in which packets are transferred from source node to destination node through the intermediate nodes (hops). The main function of multi hop WSN is to enable communication between two terminal devices through a bit of middle nodes, which are transferring information from one level to another level. On the foundation of network connectivity, it dynamically gets to determine that which nodes should get included in routing, each node involved in routing transmit the data to further

World Wide Web). The nodes can be static or dynamic [24]. Wireless Sensor Networks (WSN) will continue to play a very important role in our day to day lives. A WSN contains of sensor nodes that are powered by little unique batteries. These sensor nodes are densely arranged in the area to be monitored to sense and transmit information towards the base station. WSN can simplify structure design and operation, as the environment being monitored does not need the communication or energy infrastructure connected with wired networks [25].

Network nodes can have logical or actual communication with all devices,this communication mostly defines the type of network topology, depending on the application. Sensors are able to be pair with all the topologies types but, in some cases, the sensors may not be appropriate for all the networks. Most logical network topology tends to be defined depending on their logical roles. Centralized configuration techniques are always appropriate for networks whereby the processing power capacity specifically depends on a specific but unique device. The device is responsible for coordination, processing, and management of any information activities that is sensed within the environment. From here, it forwards the grasped information to a sink node. This, therefore, means that the sensors are quite reliable in grasping information (Karl, Holger, and Willig 2005, 105). The advantage of this network arrangement is the centralized configuration allows more energy management and roaming is usually allowed inside the network to facilitate

The purpose of the CDSWS scheme introduced in [52], is to extend the life of the network while ensuring network coverage. This proposal divides the sensor nodes into clusters based on the sensitivity of the coverage metrics and allows more than one node in each cluster to maintain activity simultaneously through the dynamic node selection mechanism. The dynamic rejection scheme was also presented to overcome the failure problem during cluster combining process, which has not been studied in depth before. The simulation results show that CDSWS outperforms some of the other algorithms in terms of coverage assurance, algorithm efficiency and energy saving. However, this concept assumes that some resource-rich nodes are available and need to be synchronized, which means maintenance costs. In addition to the burdens caused by re-clustering and re - registration making the distributed directories concept less suitable for dynamic IP-enabled LLNs.

One application example of the proposed system is illustrated in Fig. 1 (b). In this scenario, multiple mobile sensors distributed over a geographical area need to transmit data to a remote destination node. Here

Abstract— Mobile ad hoc networks will appear in environments where the nodes of the networks are absent and have little or no physical protection against tampering. The nodes of mobile ad hoc networks are thus susceptible to compromise. The networks are particularly vulnerable to denial of service (DOS) attacks launched through compromised nodes or intruders. This work proposed a new DOS attack and its defense in ad hoc networks. The new DOS attack, called Ad Hoc Flooding Attack(AHFA), can result in denial of service when used against on-demand routing protocols for mobile ad hoc networks, such as AODV, DSR.

The signal data obtained in the measurement phase is then used to approximate the position of the target node. Since, due to many factors range data often gets attenuated by noisy signal measurements, optimization methods are to be employed to filter the noise and arrive at a more definite position estimate.

In ad-hoc wireless network, mobile nodes are connected by wireless links. The network is an autonomous and self-configured. It doesn’t have fixed infrastructure or centralized management. The mobile nodes in network are free to move from one place to another. Each node has transmitter and receiver which is used to send and receives the data and communicates with other nodes which are in their communication range. If any node wants to forward packet to the node which is out of range, co-operation of other nodes required; this is known as multi-hop communication. In multi-hop communication message send and received by various intermediate nodes. The network topology frequently changes due to the mobility of nodes as they move within, move into, or move out of the network. In recent years, the ad-hoc wireless network rapidly increases being used in various applications i.e. military purpose, civilian and commercial uses without the fixed infrastructure and human interference.

Wireless sensor networks ensure a wide range of applications [1], starting fromsecurity surveillance in military and battlefields, monitoring previously unobservedenvironmental phenomena, smart homes and offices, improved healthcare, industrialdiagnosis, and many more.Main of the issues in wireless sensor network is coverage and communication problem which directly reflect on connectivity between different nodes. The coverage problem is determined to how well the sensing field is monitored or tracked by sensors. In this paper, the entire existing problem is discussed and focused. We also classify the coverage problem into three categories: area coverage, target coverage, and barrier coverage.

In this level, each sensor node sends and receives data from their neighbor nodes. The sensor node performs low computation to detect its integrity of its sensor circuits, by matching its own sensed data with received sensed data from its nearest neighbors during a certain time interval (t). However, microcontroller circuit in each sensor node tests bit data packets from member of neighbors, by comparing its own sensed data (yj) with its previous or next neighbor's sensed data (xi) to determine operational status of its sensor circuits. If sensor

13 application framework comprising of a huge number of minor vitality constrained and ease hubs. Sensor hubs self-rulingly sense, transform and impart by means of the radio medium shaping a sorted toward oneself out system design. Ordinarily, sensors report sensed information to an outer base station for further processing.[2] WSN can be characterized as an issue of gadgets, meant as hubs, which can sense the Environment and convey the data gathering from the checked field (e.g. a region of volume) through remote connections.

Abstract: Wireless Sensor Network is a collection of homogeneous/heterogeneous wireless devices used to monitor the changes in the surrounding of the wireless device. Each wireless device present in the network has the capability of sensing the changes in the surrounding environment. Homogeneous sensors are those which have same computational power, energy etc. Each node is battery powered which is used to transmit the sensed data over the network. So efficient transmission of data in Wireless Sensor Network is important and to transmit the data unaltered over the network to the receiver security is important

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 (WSNs) are presented their abilities in many vital applications such as wildlife tracking, checking heart rates of human, military applications, traffic monitoring, etc, [1]. Wireless sensors have limited resources, including limited storage, limited processing facility, and communication capability. In addition, each sensor node is powered by a battery, which has a finite size and cannot be recharged or replaced due to environmental conditions [2-5]. Actually, Sensor nodes depend on their finite resources to survive. Due to these reasons, it is important to enhance the energy efficiency of nodes to improve the quality of the application service REF. The first problem of WSNs is to minimize energy consumption in