The evolution of today's wireless and mobile technologies and personalized hand-held devices has increased the challenge to handle the trade-off between mobility, performance and cost. The user simply needs to be Always Best Connected (ABC). To make this happen, different types of criteria reflecting relevant characteristics of wireless and mobile access networks such as WLAN, UMTS and GPRS have to be established and judged. In this paper the criteria are divided into three main groups, performance, cost and accessibility. The criteria are fed into a Multi-Criteria Decision Making (MCDM) tool which is able to deliver a ranking of network links in order to become ABC. Finally, a case study with two different Generic Services (GSs) illustrates the decision making process and its outcomes in different situations.

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Seamless Connectivity in WLAN and Cellular Networks with Multi Criteria Decision Making

The Voice over Internet Protocol (VoIP) is becoming a more available and popular way of communication for the Internet users. This also applies to the Peer-to-Peer (P2P) systems and merging these two have already proven to be successful (e.g. Skype). Even the existing standards of VoIP provide an assurance of security and Quality of Service (QoS), however, these features are usually optional and supported by a limited number of implementations. As a result, the lack of mandatory and widely applicable QoS and security guarantee makes the contemporary VoIP systems vulnerable to attacks and network disturbances. In this paper we are facing these issues and propose the SecMon system, which simultaneously provides a lightweight security mechanism and improves quality parameters of the call. SecMon is intended specially for VoIP service over P2P networks and its main advantage is that it provides authentication, data integrity services, adaptive QoS and (D)DoS attack detection. Moreover, the SecMon approach represents a lowbandwidth consumption solution that is transparent to the users and possesses a self-organizing capability. The above-mentioned features are accomplished mainly by utilizing two information hiding techniques: digital audio watermarking and network steganography. These techniques are used to create covert channels that serve as transport channels for lightweight QoS measurement results. Furthermore, these metrics are aggregated in a reputation system that enables best route path selection in the P2P network. The reputation system helps also to mitigate (D)DoS attacks, maximize performance and increase transmission efficiency in the network.

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SecMon: end-to-end quality and security monitoring system

Wireless and Mobile Internet have changed the way people and businesses operate. Communication from any Internet access point, including wireless networks such as UMTS, GPRS or WLAN has enabled organizations to have a mobile workforce. However, networked applications such as web, email, streaming multimedia etc. rely upon the ability of timely data delivery. The achievable throughput is a quality measure for the very task of a communication system, which is to transport data in time. Throughput is thus one of the most essential enablers for networked applications. While in general, throughput is defined on network or transport level, the application-perceived throughput reflects the Quality of Service from the viewpoints of the application and user. The focus of the thesis is on the influence of the network on the applicationperceived Quality of Service and thus the user perceived experience. An analysis of application based active measurements mimicking the needs of streaming applications is presented. The results reveal clear influence of the network on the application-perceived Quality of Service seen from variations of application-perceived throughput on small time scales. Results also indicate that applications have to cope with considerably large jitter when trying to use the nominal throughputs. It was observed that the GPRS network had considerable problems in delivering packets in the downstream direction even when the nominal capacity of the link was not reached. Finally, the thesis discusses the suitability of wireless networks for different mobile services, since the influence of the network on the application-perceived Quality of Service is of great significance when it comes to customer satisfaction. Therefore, application-perceived Quality of Service in wireless networks must also be considered by the mobile application programmer during the application development.

On application-perceived quality of service in wireless networks

PERIMETER is a new EU FP7 project, whose main objective is to establish a new paradigm of user-centricity for advanced networking. In contrast to network-centric approaches, user-centric strategies could achieve true seamless mobility. Putting the user at the centre rather than the operator enables the user to control his or her identity, preferences and credentials, and so seamless mobility is streamlined, enabling mobile users to be “Always Best Connected” in multiple-access multiple-operator networks of the Future Internet. For this purpose, PERIMETER will develop and implement protocols designed to cope with increased scale, complexity, mobility and requirements for privacy, security, resilience and transparency of the Future Internet. These include appropriate mechanisms for network selection based on Quality of Experience; innovative implementation of “Distributed A3M” protocols for Fast Authentication, Authorisation and Accounting based on privacy-preserving digital identity models. All these mechanisms will be designed to be independent from the underlying networking technology and service provider, so that fast, inter-technology handovers will be possible.

PERIMETER: Privacy-Preserving Contract-less, User Centric, Seamless Roaming for Always Best Connected Future Internet

The paper reports on a new middleware architecture suggested for seamless handover. The middleware is part of an architectural solution suggested by Blekinge Institute of Technology (BTH) for seamless handover, which is implemented at the application layer. This architecture is sub ject for the PERIMETER STREP and MOBICOME pro jects, granted by the EU FP7 and EUREKA, respectively. Compared to the existent handover solutions, implemented at the link layer and network layer, this solution oﬀers the advantage of less dependence on physical parameters and more ﬂexibility in the design of architectural solutions. Furthermore, it allows for dynamic combinations of services and underlying transport substrates (overlays and networks). The suggested middleware, called ROMA, represents a software system with two sets of APIs, one for application writers and another one for interfacing various overlay and un- derlay systems. ROMA thus provides a transport-agnostic platform for future Internet applications. The paper provides a short description of the ROMA middleware, with par- ticular focus on API design and address translation.

ROMA : A Middleware Framework for Seamless Handover

During recent years, it has become evident that mobility functions will have a profound impact on current and future wireless networks. Users expect service connectivity anywhere and anytime without having to think about the underlying communication systems used at that particular moment in time.

On this background, this paper presents a ready-to-deploy implementation of a mobility framework that supports seamless communication and represents an important enabler for adaptive applications through its simple QoS feedback mechanism. The framework selects the best available network through a decision algorithm that takes advantage of both experience with different network types for certain types of services and a link performance monitoring concept. The impact of the proposed framework on performance in terms of processing and throughput overhead is also discussed.

Network selection box: an implementation of seamless communication

In order to meet user expectations in an ITS environment, services need efficient support from the underlying communication systems. Seamless communication is an important functionality in these systems. The PIITSA1 project is a research and demonstration project, mainly funded by Vinnova the Swedish Agency for Innovation Systems, and aims at a communication concept that delivers this seamless functionality. A framework for seamless communication has been outlined and during 2006 this concept has been implemented and evaluated. This paper presents the framework, results from the technical evaluation, and outlines the demonstration ahead. For the covering abstract see ITRD E134653.

Roland Waltersson

Papers

Network selection box: an implementation of seamless communication

Seamless communication for its applications