Mobility Prediction in Mobile Ad-Hoc Networks

A Mobile Ad hoc NETwork (MANET) is a collection of wireless mobile nodes forming a network without using any existing infrastructure. All mobile nodes function as mobile routers that discover and maintain routes to other mobile nodes of the network and therefore, can be connected dynamically in an arbitrary manner. The mobility attribute of MANETs is a very significant one. The mobile nodes may follow different mobility patterns that may affect connectivity, and in turn protocol mechanisms and performance. Mobility prediction may positively affect the service-oriented aspects as well as the application-oriented aspects of ad hoc networking. At the network level, accurate node mobility prediction may be critical to tasks such as call admission control, reservation of network resources, pre-configuration of services and QoS provisioning. At the application level, user mobility prediction in combination with user’s profile may provide the user with enhanced location-based wireless services, such as route guidance, local traffic information and on-line advertising. In this chapter we present the most important mobility prediction schemes for MANETs in the literature, focusing on their main design principles and characteristics.

Ambient Networks

This chapter introduces the Ambient Network (AN) which is a network integration solution that aims at fostering dynamic co-operation between the next generation, heterogeneous wireless and wired networks, in order to gather resources within and across networks to provide new services to end users. First, it depicts the main characteristics of AN before describing the Ambient Control Space, which is the space where functional entities managing the networks and the services are active, and the interfaces. Then it focuses on the SATO (Service-aware Adaptive Transport Overlays), which is a service overlay networks deployed on top of the underlying heterogeneous physical networks and tailored according to the services‘ requirements and users‘ context. This chapter aims at giving the readers a good overview of what Ambient networks are since they will be present in the next years everywhere.

Vehicular Communications Networks

Vehicular communications networks (VCNs) are created by vehicles equipped with short and medium range wireless communication technology. They include vehicular ad-hoc networks (VANETs), vehicle-to-vehicle and vehicle-to-infrastructure communications. VCNs enable a plethora of important applications and services, ranging from active safety or safety of life applications to traffic information, music/maps download and multi-hop internet connection. Recently, the promises of wireless communications to support vehicular safety applications have led to several national/international projects around the world. These include the consortia like Vehicle Safety Consortium (US), Car-2-Car Communication Consortium (Europe) and Advanced Safety Vehicle Program (Japan), standardization efforts like IEEE 802.11p (WAVE), and field trials like the large-scale Vehicle Infrastructure Integration Program (VII) in the US. All these efforts have as a main goal to improve safety in vehicular environments by the use of wireless communications, but also consider transport efficiency, comfort and environment. In comparison to other communication networks, VCNs come with unique attractive features: unlimited transmission power, predictable mobility and plethora of potential applications. However, to bring its potency to fruition, VCNs have to cope with formidable challenges that include: rapidly changing topology subject to frequent fragmentations and congestions, lack of connectivity redundancy, and the stringent application requirement on real-time and robust message delivery. In this chapter, we present a detailed description of the state of the art of this fast-moving research area pointing to research, projects and standardization efforts that have been done. We explore the unique features and challenges that characterise these highly dynamic networks as well as their requirements with respect to applications, types of communication, self-organization and security. We discuss various forwarding and routing strategies focussing on position-based techniques including ‘anchor-based routing‘. We survey various ‘intelligent flooding’ and information dissemination approaches. Scenarios for highways and cities are taken as example. We conclude by exploring future research directions in this field.

Service Discovery in Mobile Ad-Hoc Networks

Service discovery plays a relevant role in mobile ad hoc environments. Indeed, upon joining a self-organizing network, mobile nodes should be able to explore the environment to learn about, locate, and share the available services. As a result, many researches were performed in this area. Recently, research is being directed towards integrating the service discovery into the routing protocols. This chapter presents the basic concepts of service discovery and their related issues. It also describes the service discovery challenges that arise due to the properties of mobile ad hoc networks. The chapter is concluded by presenting some observations and discussing the current challenges to provide guidelines for possible improvements.

Mechanisms for Automatic Web Service Composition

This chapter introduces the web services composition as a means of studying efficient integration of the existing web services to satisfy users’ requirements. It discusses the web services composition definition, combined with the current web services composition methods, and divides those methods into two categories: AI-based methods and Non-AI methods. Also, the authors present the features and the comparison of these two categories, to assist researchers in the understanding of web service composition in a variety of contexts.

Routing in Asymmetric Wireless Ad-Hoc Networks

The presence of asymmetric links is a common and non-negligible phenomenon in many ad-hoc networks, including MANETs and sensor networks. Asymmetry is caused by node mobility, heterogeneous radio technologies, and irregularities in radio ranges and packet loss patterns. Most existing ad-hoc routing protocols either assume fully symmetric networks or simply ignore any asymmetric links. In the first case, route discovery can fail when the symmetry assumption does not hold true, e.g., many reactive routing protocols rely on a two-phase communication process, where the same path is used to communicate between a sender and a receiver. If a single link on this path is asymmetric, the route establishment may fail. In the second case, asymmetric links are identified and explicitly ignored in the route establishment phase. This can lead to route discovery failure if there is no symmetric path between a sender and a receiver or it can lead to less than optimal routes. This document provides an overview of routing protocols that explicitly consider asymmetric links in the route discovery phase and introduces robust mechanisms that bypass asymmetric links to ensure successful route establishment.

Calling Police Using SMS

In this chapter, a method is proposed to contact the Police with mobile phones and via SMS (Short Message Service). In this method, when a person wants to contact the Police, he must only press a special key on his mobile phone for a short time to launch a special program. This program sends current location of the person using GPS system and sends it periodically with other useful information such as name, home and work address of that person automatically to the Police Station using SMS. In this method, there is no need to talk and a person can contact the Police easily and tell them the place which crime has occurred. In addition, there is no busy line problem. This method has low cost and can be run on many mobile phones This method is implemented using JavaME (Java Platform Micro Edition) programming language and tested on a Nokia N71 mobile phone by using an ‘Evermore BT-R700’ GPS receiver.

Middleware Technologies for Ubiquitous Computing

Middleware handles many important functionalities for ubiquitous computing. The authors distinguish various middleware technologies providing key elements for all applications‘ requirements such as discovery, adaptation/composition, context management, and management of ubiquitous applications. In this chapter, they propose a classification for some of the most employed ubiquitous middleware. The classification was established upon the challenges raised by ubiquitous computing – effective use of smart spaces, invisibility, and localized scalability - and upon how the various ubiquitous middleware respond to them in terms of interoperability, discoverability, location transparency, adaptability, context awareness, scalability, security, and autonomous management. This classification shows that if many middleware are mature enough and offer specific functionalities respecting the properties of ubiquity, a real lack is noticed in having an interoperable, autonomous and scalable middleware for the execution of ubiquitous applications. The development of the service-oriented paradigm, the semantics, the Web middleware, and the ambient intelligence shows the new trend the middleware research field is engaged in.

MAC Protocols for Wireless Sensor Networks

The chapter describes related work on medium access control protocols for wireless sensor nodes. We focus on scheduled and contention-based protocols that have been proposed by the research community during the last few years. In particular, we evaluate the potential to save energy of several representative protocols, namely LMAC, TEEM, and WiseMAC. This has been done by measurements of implementations in real sensor networks. The measurement results show that by sophisticated MAC protocol design we can significantly improve the energy-efficiency and increase the lifetime of a sensor node. Real-world measurements are important to determine power consumption parameters of sensor nodes.