Nt1310 Unit 1 Ad-Hoc Network

The main base for the protection of your own you have to be a security think (what I mean thinking any security you have the same way of thinking that enjoyed by penetration) experts

The wireless local area network diagram uses a combination of three different topologies. The topologies represented are Ring, Star, and Mesh.

There are three kinds of MQTT-SN components: clients, gateways and forwarders. MQTT-SN clients connect themselves to a MQTT server via a MQTT-SN gateway using the MQTT-SN protocol. A MQTT-SN gateway may or may not be integrated with a MQTT server. In case of a stand-alone gateway, the MQTT protocol is used between the MQTT server and the MQTT-SN gateway. Its main function is the translation between MQTT and MQTT-SN. MQTT-SN clients can also access a gateway via a forwarder in case the gateway is not directly attached to the network. The forwarder simply encapsulates the MQTT-SN frames it receives on the sensor network side and forwards them unchanged to the gateway; in the opposite direction, it decapsulates the frames it receives from the

The proposed concept is implemented as a prototype and this document gives a detailed insight about the prototype. The prototype considers wired and wireless communication and the data exchanges between them. All the simulations are executed on a windows laptop.

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.

The Wireless Routing Protocol (WRP) is a table-based distance-vector routing protocol. Each node in the network maintains a Distance table (DT), a Link-Cost table, a Routing table and a Message Retransmission list. The DT contains the network observation of the neighbours of a node. It contains a matrix where each element contains the distance and the one

The Ad-hoc network is a collection of mobile nodes which can communicate without each other with the help of wireless. There is no former communication infrastructure in MANETs [1]. There is no fixed infrastructure and centralized control in MANETs therefore nodes can communicate the network at any time. All nodes are supposed to be equal in processing power. All node can act either as a host or as a router to direct the packet from source to destination in the network. All nodes acts as routers and are capable of discovering and maintaining routes to propagate packets to the destinations.[2] There are lots of advantages promised of network in terms of cost and flexibility compared to network with infrastructures. Ad-hoc network are used for a great variety of applications such as data

Many networks are infrastructure less networks where the nodes can configure dynamically to form a useful network. There are many challenges in wireless networks as explored in [1]. The challenges are as follows.

Ad hoc networks are a new prototype of wireless communication for mobile hosts (which we call nodes).In an Ad hoc network, there is no fixed particular infrastructure such as base stations and mobile nodes. Mobile nodes that are within each other’s radio frequency range communicate directly via wireless links, while those that are far apart depend on other nodes to forward messages as routers. Ad hoc networks are peer to peer networks of mobile nodes. They are mostly used in sensor networks, habitat monitoring and robotic collaboration. In the recent times, Ad hoc networks have evoked increasing interest as adjustable distributed application environments. These days many people are using different types of wireless devices, such as laptops, mobile phones, PDAs (personal digital assistant) and mp3 players, as part of their professional and private lives. For the most part, these devices are used separately because the network applications do not interact. Ad hoc wireless communication between devices can be defined as a scheme, often indicated as the Ad hoc network, which allows devices to establish communication between the nodes anytime and anywhere to transfer data without the aid of a central infrastructure. The concepts of mobile Ad hoc networking along with its applications that can be envisioned are being described in this report. Ad hoc networking covers different types of positions in a communication. An Ad hoc Network framework can comprise of a

Power efficiency is the first factor that directly affects the performance of the nodes and hence of the overall sensor network. For better and desired performance, the nodes of a WSN must be efficient in terms of power which in simple words means that the duty cycle of the nodes must be made small [5]. The design considerations must take into account the sleeping mode of the nodes when there is no activity thereby reducing power consumption and contributing to performance enhancement. However, the sleep mode of nodes has the main disadvantage that if any of the nodes remains in the sleep mode for a significant chunk of time, it is likely that communication with neighbors nodes may come to a halt. Also, a reduced duty cycle for the network nodes leads to threatening the network reliability. The data as well as the control packets that maintain the routing and communication among the nodes of the sensor network will also have a delayed reception.

An important issue for mobile ad hoc network is the routing protocol design. Due to frequent changes in the topology of the network this becomes a major technical challenge. Node failures and link breakages in the network may cause loss of the network resources. In signal strength based AODV, protocol measures signal strength between nodes and compare with RSSI threshold values. If it is greater than threshold value then it is accepted for further processing otherwise it is discarded. If it will not find any route between source and destination then it will switch to normal AODV which selects route on the basis of minimum hop count. The benefit of this scheme is by selecting a strong route to the destination we can increase the lifetime of the network.

For achieving this goal, physical deployment of the nodes and the sample periods are pre-determined by the scientists. To ensure that data is delivered as expected is the real role of the network. For achieving this goal it is necessary to reduce the network complexity as much as possible from the services and its application. It is possible to optimize communication performance for that application-not for a generic set of users as each node executes a single application. For achieving this it is necessary to translate them into a set of goals for media access protocol to satisfy the requirement of wireless sensor network deployment and monitoring application. For WSNs application, the common goals for a MAC protocol are:

Connectivity and topology control: Some approaches tried to improve the system reliability by carefully designing the connectivity or topology of wireless networks. Paper [50] addresses the problem of fault tolerant deployment of wireless ad-hoc networks. Based on the pre-assumed transmission range, the authors propose a scheme to calculate the probability that a given network is k-connected. Based on the intensive deployment, the redundant sensor nodes are used to cope the random working nodes failure. Following the similar idea, a distributed algorithm is proposed in [52]. By deploying calculated necessary number of extra nodes in the given network, the objective of fault-tolerant topology control can be achieved. However, due to the limited space and cost constraint, adding redundant nodes to a deployed WSN may not always be an acceptable solution. Another fault-tolerant topology control algorithm is presented by Li and Hou in [53], in which a spanning subgraph is computed by each node. If a pair of vertices is not k-connected, an extra edge will be added between these two vertices. The authors further prove that the resultant global network is k-connected. In [54], by considering the mobility of nodes, the author shows the mobility resilient topology control protocols. The author classifies the topology control protocols into two types. 1) In this case, the topology is built and maintained by each node based on its own knowledge about its neighbors. According to its own

Mobile ad hoc network (MANET) falls in the category of wireless ad hoc network, and is a self-configuring network. Each device is free to move independently in any direction, and hence will change its link with other devices

Recent trends in compact computing and wireless technologies are expansion of ad hoc network. Ad hoc network consists of versatile flat forms which are free to move expeditiously. Ad hoc networks are multi-hop network that use wireless communication for transmission without any fixed infrastructure. The networks are form and deform on-the-fly without the need for any system. Ad hoc structure does not require an access point, it is easy to setup, especially in a small or temporary network. Each node in the network forwards the packet without the need of central administration. In ad hoc network, node acts as a router to send and receive the data. An advantage of the system is robustness, flexibility and mobility. Ad hoc network are capable for analyzing radio propagation environment to optimize the performance. This typically requires that the network node have positioning capability as well as memory to recall geographical local condition. An ad hoc network typically refers to any set of network where all devices have equal status on a network and are free to associate with any other ad hoc network device in link range. Ad hoc network often refers to a mode of operation of IEEE 802.11 wireless networks. This review is focused on the applications, advantages and challenges of ad hoc networks.