Broadcasting in Hybrid Ad Hoc Networks.

In this paper, we consider hybrid ad hoc networks, which are composed of two kinds of nodes, regular ones and nodes with additional capabilities. For example, multi-hop cellular and wireless Internet networks consist of static or mobile nodes, and fixed access points which provide an access to an infrastructure. In such a network, each node may use direct or multihop link to connect to an access point, allowing a greater mobility. The goal of this paper is to provide protocols for broadcasting data in such an environment, by taking advantage of the presence of access points to optimize the broadcast, either from an energy consumption or from a latency point of view. We thus consider known protocols for pure ad hoc networks and adapt them to hybrid ad hoc networks. These protocols are the Blind Flooding, the Neighbor Elimination Scheme, the Multipoint Relay protocol and the generalized Self-Pruning Rule (algorithm that elects some dominant nodes to relay messages). We give some experimental data for these modified protocols to compare them to their original version, so that we are able to emphasize the gain obtained thanks to our proposed modifications

Classification and Comparative Study of Routing Techniques in Adhoc Wireless Networks

Wireless systems have been in use since 1980s. We have seen their evolutions to first, second and third generation's wireless systems. Wireless systems operate with the aid of a centralized supporting structure such as an access point. These access points assist the wireless users to keep connected with the wireless system, when they roam from one place to the other. The presence of a fixed supporting structure limits the adaptability of wireless systems. In other words, the technology cannot work effectively in places where there is no fixed infrastructure. Future generation wireless systems will require easy and quick deployment of wireless networks. This quick network deployment is not possible with the Infrastructured wireless systems. Recent advancements such as Bluetooth introduced a new type of wireless systems known as ad-hoc networks. Ad-hoc networks or "short live" networks operate in the absence of fixed infrastructure. They offer quick and easy network deployment in situations where it is not possible otherwise. Ad-hoc is a Latin word, which means "for this or for this only." Mobile ad-hoc network is an autonomous system of mobile nodes connected by wireless links; each node operates as an end system and a router for all other nodes in the network. Nodes in ad-hoc network are free to move and organize themselves in an arbitrary fashion. Each user is free to roam about while communication with others. The path between each pair of the users may have multiple links and the radio between them can be heterogeneous. This allows an association of various links to be a part of the same network. A mobile ad-hoc network is a collection of mobile nodes forming an ad-hoc network without the assistance of any centralized structures. These networks introduced a new art of network establishment and can be well suited for an environment where either the infrastructure is lost or where deploy an infrastructure is not very cost effective. The popular IEEE 802.11 "WI-FI" protocol is capable of providing ad-hoc network facilities at low level, when no access point is available. However in this case, the nodes are limited to send and receive information but do not route anything across the network. Ad-hoc networks can operate in a standalone fashion or could possibly be connected to a larger network such as the Internet. An ad-hoc network has certain characteristics, which imposes new demands on the routing protocol. The most important characteristic is the dynamic topology, which is a consequence of node mobility. Nodes can change position quite frequently; the nodes in an ad-hoc network can consist of laptops and personal digital assistants and are often very limited in resources such as CPU power, storage capacity, battery power and bandwidth. This means that the routing protocol should try to minimize control traffic, such as periodic update messages. The Internet Engineering Task Force currently has a working group named Mobile Ad-hoc Networks that is working on routing specifications for ad-hoc networks. This M.Phill thesis evaluates some of the protocols put forth by the working group. This evaluation is done by means of simulation using Network simulator 2 from Berkeley. This work aims at classification of the existing routing protocols of adhoc wireless networks using some definite parameters. After classification of routing protocols of adhoc wireless network, their comparative study was undertaken in order to yield category wise distribution. Furthermore performance evaluation of these protocols was carried out by employing different parameters like fading models, mobility models, traffic patterns etc using the network simulator NS-2 Hence I explore and evaluate different methods for validation of ad hoc routing protocols which are used to set up forwarding paths in spontaneous networks of mobile/Adhoc devices to accomplish the above mentioned comparative study and classification

Mobile ad-hoc networks: MANET

Currently in 2018, 7.6 billion people are in the world, and 8.6 billion mobile devices. As mobile phones have completely changed the meaning of the term to be available, a similar change in the wait and laptops users is, so it is only a matter of time before the new way to use your notebooks will change your habits and make life easier. As modern man is becoming increasingly accustomed to the availability of the 'network' (the Internet), where he can find almost every necessary information, he is increasingly integrating in his life, for example, if one wants to quickly find out where one can buy a book of a particular author, or on a specific topic, which pharmacies are open, how to find the street etc. Today, wireless internet access at airports, restaurants, hotels is almost everywhere , and such approaches are based on previously installed infrastructure such as wireless access point (wireless access point) through which you connect your device to the Internet or communicate with another person and exchange data. This way of accessing the Internet while on the go-via a laptop computer would require an infrastructure like the GSM network. That is why we started to develop a different network model, which are ad-hoc networks, that is, Mobile Ad-hoc Networks, as an ad-hoc network

Engineering a Suburban Ad-Hoc Network

Networks are growing in popularity, as wireless communication hardware, both fixed and mobile, becomes more common and affordable. The Monash Suburban Ad-Hoc Network (SAHN) project has devised a system that provides a highly secure and survivable ad-hoc network, capable of delivering broadband speeds to co-operating users within a fixed environment, such as a residential neighbourhood, or a campus. The SAHN can be used by residents within a community to exchange information, to share access to the Internet, providing last-mile access, or for local telephony and video conferencing. SAHN nodes are designed to be self-configuring and selfmanaging, relying on no experienced user intervention. Thus, they are suitable for use by the general public, in ‘plug-and-play’ fashion. This paper investigates possible architectures for an implementation of the SAHN (Tyson 2005), and presents a real-world prototype. The prototype presented takes the form of a Linux kernel module, and a user-space daemon

A Multichannel MAC Protocol for IoT-enabled Cognitive Radio Ad Hoc Networks

Cognitive radios have the ability to dynamically sense and access the wireless spectrum, and this ability is a key factor in successfully building Internet-of-Things (IoT)-enabled mobile ad hoc networks. This paper proposes a contention-free token-based multichannel MAC protocol for IoT-enabled Cognitive Radio Ad Hoc Networks (CRAHNs). In this, secondary users of CRAHNs detect activity on the wireless spectrum and then access idle channels licensed by primary users. CRAHNs are divided into clusters, and the channel to use for transmission is determined dynamically from the probability of finding idle primary-user channels. The token-based MAC window size is adaptive, with adjustment according to actual traffic, which reduces both end-to-end MAC contention delay and energy consumption. High throughput and spatial reuse of channels can also be achieved using a dynamic control channel and dynamic schemes for contention windows. We performed extensive simulations to verify that the proposed method can achieve better performance in mobile CRAHNs than other MAC schemes can

Cooperation as a Service in VANET: Implementation and Simulation Results

The past decade has witnessed the emergence of Vehicular Ad-hoc Networks (VANET), specializing from the well-known Mobile Ad Hoc Networks (MANET) to Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) wireless communications. While the original motivation for Vehicular Networks was to promote traffic safety, recently it has become increasingly obvious that Vehicular Networks open new vistas for Internet access, providing weather or road condition, parking availability, distributed gaming, and advertisement. In previous papers [27,28], we introduced Cooperation as a Service (CaaS); a new service-oriented solution which enables improved and new services for the road users and an optimized use of the road network through vehicle\u27s cooperation and vehicle-to-vehicle communications. The current paper is an extension of the first ones; it describes an improved version of CaaS and provides its full implementation details and simulation results. CaaS structures the network into clusters, and uses Content Based Routing (CBR) for intra-cluster communications and DTN (Delay and disruption-Tolerant Network) routing for inter-cluster communications. To show the feasibility of our approach, we implemented and tested CaaS using Opnet modeler software package. Simulation results prove the correctness of our protocol and indicate that CaaS achieves higher performance as compared to an Epidemic approach

Last mile mobile hybrid optical wireless access network routing enhancement

This study focuses on mobile ad hoc networks (MANETs) that support Internet routing protocol imposing stringent resource consumption constraints of Quality of service (QoS). The mobile Internet causes the on-going issue of inefficient use of the MANET resources due to its random nature of wireless environments. In this paper, the new improved architecture of the last mile mobile hybrid optical-wireless access network (adLMMHOWAN) is proposed and designed to tackle the arised issues. The proposed design is based on a unified wireless-wired network solution required the deployment of MANET-based wireless fidelity (WiFi) technology at the wireless front-end and wavelengths division multiplexing passive optical network (WDM PON) at the optical backhaul. The critical performance metrics such as network capacity and energy consumption based on modified AODVUU routing protocol using OMNeT++ software is analyzed with 2 scenarios, namely the number of nodes and mobility speed. This mode of communication results in better QoS network capacity of 47.07% improvement, with 26.85% reduction of lower energy resource consumption for mobile wireless front-end over passive optical network backhaul architecture when compared with the existing work of oRiq scheme that focus on improvement in MANETs