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In this chapter the SmartME application is introduced to demonstrate the idea presented in Chapter 10 about Digital Ownership Management on real mobile devices. The main goal of the SmartME application is to enable spontaneous collaboration between its users establishing ad hoc peer-to-peer networks using Bluetooth. Within these networks the users are able to provide each other with two different services: The CollectME service is derived from the idea of digital collectibles. When the application is initially started the user is given an incomplete collection of soccer cards (currently containing the logos of Danish soccer teams). The objective from a user’s perspective is to complete an entire collection. A new user is given twelve randomly selected cards, where some of them are duplicates and the user can then start exchanging cards. To enable the exchange of cards the user can access his current collection of soccer cards, here he can configure his wish list and trade list. The wish list contains the cards that the user is currently looking for and the trade list the cards that the user wants to trade as shown in Figure 11.1.

As Voice-over IP (VoIP) services are dominating the telephony backbone already, the main focus of this project is to investigate the possibility of using VoIP over the last hop between the home IP router and the mobile phone. Most homes are already equipped with fixed IP communication lines, and many network providers plan to use VoIP to the IP router at the homes. The project investigates the possibility to use VoIP between the mobile phone, hosting the personal information, and the home router. As a first result a Walkie-Talkie has been developed allowing Push-to-Talk services in a Peerto-Peer manner called the scenario as shown in Figure 12.1.

Summary. This chapter provides an introduction to cooperative techniques in wireless networks, with emphasis on the wireless devices. A motivating introduction is first presented, discussing the scope, scenarios, and potentials of cooperative techniques. Some key challenges are also identi.ed and discussed. Cooperative approaches are then classi.ed according to the employed principles, scope, and goals as communicational, operational, and social cooperation. Finally, a very promising paradigm for cooperation in heterogeneous wireless networks is proposed and explained. This approach is based on a composite centralized-distributed architecture of two combined access networks, a wide area cellular network and a local short-range network.

Summary. A simple Python program transmitting a short text message over the GSM network without causing any costs for the customer is presented. The application is intended to underline the strength of cooperation in cellular controlled peer-to-peer networks. Furthermore an example how to extend the Python library with Symbian/C++ is given.

Summary. Peer-to-peer (P2P) file sharing is a relatively new addition to the growing list of mobile-based technologies. The advanced connectivity features and powerful hardware of new generation mobile devices facilitates the implementation of even the most complex P2P technologies. The characteristics of the P2P architecture, such as reliability, easy one-to-one communication, and extensible distribution of resources, make it one of the most suitable networking technologies for mobile systems. In this chapter, we give a summary of our experience in implementing the Gnutella and the BitTorrent file sharing technologies on a mobile platform. We examine the particular protocols and emphasize the points relevant to the mobile implementation.

Summary. This chapter describes the implementation of wireless cooperative networks. The application was developed to prove energy savings for cooperative mobile devices. 16.1 Motivation As previously introduced, cooperation among mobile devices controlled by a cellular network is a novel wireless architecture capable of overcoming problems and limits encountered by conventional wireless networks. To prove these claims, a very simple application has been implemented to advocate the use of cooperative behavior in wireless networks. Furthermore the application can act in a stand-alone fashion too, without cooperation. Both approaches are compared with each other. The application itself underlies the same concept as BitTorrent in the wired world. In the first step we are not focusing on a commercial application. Larger interest lies in the understanding of the cooperative concepts and its related performance compared to state-of-the-art technologies. In the end of the chapter we will implement the new cooperative concept in the SymTorrent application explained before. Chapter 17; Summary. This chapter provides an introduction to cross-layer protocol design. Cross-layer design is needed in order to enhance data transmission across especially wireless network connections. This enhancement is achievable by being able to optimize certain parameters jointly across multiple layers instead of considering each layer separately. Cross-layer protocol design is a principle that provides the possibility of enhancing the architecture and operation of the layered protocol stack by allowing communication between nonadjacent layers as an extension of what is possible in the OSI model. We briefly summarize the layered network protocol stack concept of the ISO OSI model and explain cross-layer communication in this context. We provide an overview of di.erent categories of exchanging data across layers of the network protocol stack and point out advantages and drawbacks of di.erent approaches. We provide examples from the literature of such approaches. Similarly, we review a number of recent examples from research literature of how cross-layer protocol design is being put to use. The examples provide an overview of which layers are involved in di.erent cross-layer optimization approaches. The examples also provide an overview of which technological areas are currently considered in - and which optimization techniques employ - cross-layer design.

Summary. Service discovery deals with locating services which can be used to accomplish a task. For example discovering a printer to print documents on, or locating a shop offering the service of hairdressing. When you locate a service you usually obtain an address which you use to invoke the o.ered service. Here in this chapter we will start by looking at an example of service discovery from human life, with a short story of a pizza restaurant which o.ers the service of baking pizzas and see how customers can discover it. Next, we will have a look at how those methods from the pizza-story can be applied in computer networks. Finally, an introduction to UPnP is given as an example of a service discovery system.

Summary. This chapter gives a first idea how cross-layer design could be carried on mobile devices improving the overall performance of the communication system. As an example we refer to multimedia services that are conveyed over the Bluetooth technology. To increase the bandwidth efficiency on the wireless medium IP header compression schemes are used.

Summary. Pervasive computing with mobile devices and wireless sensor networks has been identified as a future area of research. Wireless sensors have the possibility to sense the surrounding world, while mobile devices offer a sophisticated user interface together with the well-known cellular services to the symbiotic partnership. The strength of the envisioned convergence is shown throughout the next chapters and here possible architecture forms are classified.

Summary. One of the limiting factors in mobile applications development is the restrictions imposed on the user interface through reliance on the standard ITU-T keyboard which is only really optimal for dialling phone numbers. However, with the convergence of the mobile phone with other sensing technologies, such as Radio Frequency Identi.cation (RFID) and the associated Near Field Communications (NFC), Cameras, and 3D motion sensors, we have the opportunity to use new relational interfaces [12] based on touch, vision, and movement to create new and exciting experiences for mobile application users. In this chapter we present the technologies and the software Application Program Interfaces (APIs) associated with these sensors together with methodologies for their use.