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Byline: Jorma Lilleberg (1), Ramjee Prasad (2) Keywords: UMTS; 3G; 4G; IMT-2000; space-time coding; multiuser detection; global information multimedia village; software radio; communication processor; adaptive radio interface; receiver architecture; multi standard Abstract: The first third-generation (3G) systems are going to be implemented within the year 2001. Academia and industry are, however, already looking for means to improve the system performance further. Spectral efficiency and higher data rate are the goal. In order to achieve this goal, several means have to be combined. The most important of these are interference cancellation and multiuser detection, optimum space-time processing and adaptive modulation and coding. In the future several wireless systems having different performance characteristics, system structure and parameters will exist. This heterogeneity will make the seamless handover from system to system difficult if not appropriately solved. 4G (fourth generation) is an acronym without any generally accepted concept. We describe some desirable goals and features of the 4G systems. Author Affiliation: (1) Nokia Mobile Phones, Elektroniikkatie 3, P.O. Box 50, FIN-90571, Oulu, Finland (2) CPK, Aalborg University, Fredrik Bajers Vej 7A5-205, 9200, Aalborg, Denmark Article History: Registration Date: 04/10/2004

Byline: Shingo Ohmori (1), Yasushi Yamao (2), Nobuo Nakajima (2) Keywords: mobile communications; broadband access; 4G; ITS; HAPS Abstract: The forthcoming mobile communication systems are expected to provide much variety of services from high quality voice to high definition videos through high data rate wireless channels at anywhere in the world. High data rate requires broad frequency bands, and sufficient broadband can be achieved in higher frequency bands such as microwave, Ka-band and millimeter-wave. Broadband wireless channels have to be connected to broadband fixed networks such as the Internet and local area networks. The future generation systems will include not only cellular phones, but also many new types of communication systems such as broadband wireless access systems, millimeter-wave LAN, intelligent transport systems (ITS) and high altitude stratospheric platform station (HAPS) systems. The key words in the future generations of mobile communications are 'multimedia communications', 'wireless access to broadband fixed networks' and 'seamless roaming among different systems'. This article discusses the future generations mobile communication systems. Author Affiliation: (1) Communications Research Laboratory, Ministry of Posts and Telecommunications, 184-8795 Koganei, Tokyo, Japan (2) Wireless Laboratories, NTT Mobile Communications Network, Inc, Japan Article History: Registration Date: 04/10/2004

Byline: Sunho Lim, Chansu Yu, Chita R. Das Recent studies discovered that many of social, natural and biological networks are characterised by scale-free power-law connectivity distribution. We envision that wireless networks are directly deployed over such real-world networks to facilitate communication among participating entities. This paper proposes Clustered Mobility Model (CMM), in which nodes do not move randomly but are attracted more to more populated areas. Unlike most of prior mobility models, CMM is shown to exhibit scale-free connectivity distribution. Extensive simulation study has been conducted to highlight the difference between Random WayPoint (RWP) and CMM by measuring network capacities at the physical, link and network layers.

Byline: Tao Zhou, Yaobin Lu, Bin Wang, Kwok-Kee Wei This research analyses factors affecting mobile community user participation from a social capital perspective. The six factors of social capital are categorised into three dimensions: the structural dimension, the cognitive dimension, and the relational dimension. User participation intention includes two variables: the intention to view and the intention to post. We collected 370 valid questionnaires and performed data analysis using Structural Equation Modelling (SEM). The results showed that trust had the strongest effect on the intention to view, whereas identification with the community had the strongest effect on the intention to post. Thus, mobile community providers need to focus on the relational dimension of social capital in order to promote user participation in their communities.

Byline: Ye Ouyang, M. Hosein Fallah More than 217 UMTS licenses have been issued by June 2007. Mobile operators, especially those with GSM legacy networks, prefer UMTS R4 technique to evolve their existing 2G GSM networks. UMTS R4 technique provides a smooth path to bridge legacy TDM-based network to an IP-based soft-switched network. This paper describes the basic architecture and topology of UMTS R4 core network and introduces two options in network planning: flat structure or layered structure. To propose an evolution path, the paper then suggests a 'threelayer structure' solution to seamlessly converge UMTS R4 core network with legacy GSM core network. The proposed solution approach achieves the all-IP vision and is capable of convergence with IMS and EPC.

Byline: Lei Wang, Yimin Wang, Yaping Lin For m-covered and connected sensor networks, a new distributed node scheduling algorithm is designed, which can allocate all the nodes in the sensor network into k (k ≤ m) different groups without requiring location information. Theoretical analysis and simulation results show that the newly proposed algorithm has better node scheduling performance and can prolong the lifetime of the sensor networks more effectively than the traditional random-based node scheduling scheme.

Byline: Aaron L. Phillips, Timothy I. Matis In this paper, we show that the use of global positioning system (GPS) information in a mobile ad hoc network (MANET) running the file transfer protocol (FTP) over the transmission control protocol (TCP) can be used to block the inclusion of unreliable links within a discovered route by not allowing the nodes outside of a given distance to participate in their formation. In doing so, this creates more reliable routes over time and lowers the amount of network overhead necessary to maintain the flow of data packets. This approach to route formation is validated using the NS-2.31 network simulator under different types of multipath fading models as well as varying network dimensions and node densities. While this GPS blocking scheme has been explored previously in a constant bit rate (CBR) over a user datagram protocol (UDP) setting, it has not yet been tested previously under the more common real-world conditions of FTP running over TCP.

Byline: B. Hughes, V. Cahill The unpredictability of mobile ad hoc networks (MANETs) characterised by dynamic membership, host mobility and time-varying connectivity, poses significant challenges to achieving real-time communication guarantees. In this paper we describe both a new communication model, the space-elastic model, that provides timely communication in a desired geographical area and a new real-time ad hoc routing protocol, the space-elastic adaptive routing (SEAR) protocol, that supports the space-elastic model. In a MANET, timeliness guarantees may not always be achievable within the complete desired network topology. The space-elastic model makes use of a trade-off between time and space to provide timely communication in an adaptable geographical area. In addition, the model guarantees timely notification of adaptations to this area to applications, which may then be used by them as the basis for behavioural changes. We have experimentally validated the model's guarantees of both timely message transmission and adaptation notification in the real world. Our results show that both low-jitter message transmission (e.g., worst case jitter of only 163 μs over three hops regardless of receiver mobility) and notification of adaptations within known time bounds are achieved, thereby demonstrating the feasibility of the model.

Byline: M. Bheemalingaiah, M.M. Naidu, D. Sreenivasa Rao, G. Varaprasad With the advance of wireless communication technologies, small-size and high-performance computing and communication devices like laptops and personal digital assistants are increasingly used in daily life. After the success of second generation mobile system, more interest was started in wireless communications. This interest had led to two types of the wireless networks such as infrastructure wireless network and infrastructure less wireless network, also called mobile ad hoc network (MANET). The research challenges in MANET are related to the routing, security, reliability, scalability, quality of services, internetworking, power consumption and multimedia applications. All the mobile nodes of MANET operate on the battery power; hence power consumption becomes an important issue in MANET. It proposes a power-aware node-disjoint multipath source routing (PNDMSR) for real-time traffic, which balances the node energy utilisation to increase the network lifetime. It takes the network congestion into account to reduce the routing delay across the network, and increases the reliability of the data packets reaching the destination.

Byline: Geethapriya Thamilarasu, Ramalingam Sridhar In mobile ad hoc networks (MANET), lack of centralised monitoring point and lack of clear line of defense pose serious challenges for intrusion detection systems (IDS). In this paper, we present CIDS, a cross-layer based intrusion detection system with enhanced security performance in mobile ad hoc networks. We utilise cross-layer interactions to gather measurements from different protocol layers to detect attacks with increased accuracy. We present a case study to analyse packet drop detection in ad hoc networks using cross-layer techniques. Compared to traditional watchdog detection, CIDS is more effective in distinguishing network misbehaviour from genuine network irregularities. Simulation results based on extensive experiments illustrate the robustness and reliability of CIDS through higher detection rate and lower false positives.

Byline: Shuchih Ernest Chang Pervasive computing may provide multiple modes of interface for end users to access the internet applications at anytime from anywhere using any device. This article describes how multimodal user-interface pages for supporting various wireless devices can be implemented with multimodal transformation. It also illustrates how a Multimodal Web System (MWS) could be voice-enabled to support an interactive voice channel. This study provides insights for the design and implementation of successful business applications to catch the revolutionary opportunity and benefit of voice-enabled MWSs. In doing so, it contributes to the body of knowledge associated with the emergent pervasive computing environment.

Byline: Angappa Gunasekaran, Ronald E. McGaughey Mobile Commerce (M-Commerce) is any direct or indirect transaction conducted and facilitated through a wireless telecommunication network. M-commerce technologies have the potential to improve consumers' lives, spawn new businesses and make existing businesses more profitable. The flexibility and convenience of new wireless technologies make anywhere, anytime Electronic Commerce (E-Commerce) and 'always on' internet a reality. Most companies and stakeholders have not completely grasped the complexities, challenges, opportunities and ramifications of m-commerce. Issues and obstacles abound in this new frontier for business, consumers and regulators; moreover, these issues and obstacles warrant the attention of both researchers and practitioners, if m-commerce is to reach its potential. We reviewed the literature to identify major issues and obstacles in m-commerce. We present them in a framework to assist practitioners in understanding the challenges they face with m-commerce and to identify research opportunities.

Byline: Thorsten Caus, Stefan Christmann, Svenja Hagenhoff Experts predict context-tailored contents to be the future profit earner of mobile communication. On the other hand, mobile applications and services suitable for tailoring and delivering those contents have low market penetration so far. A lack of standardisation concerning the handling of context-information and high technical complexity involved in the development of mobile applications are reasons for this situation. This article presents 'Hydra', a framework to simplify and shorten the development of context-aware mobile applications and thus render the development of these applications more economically viable.

Byline: Dimitar Radev, Izabella Lokshina In this paper, we present the Universal Mobile Telecommunication System (UMTS) core network model with calls that belong to one of four service classes and arrive randomly. Arriving calls are granted service based on specific service class, required maximum and minimum bandwidth and available network resources. Performance of priority-based dynamic capacity allocation, suitable for the Wireless ATM (WATM) system is analysed. Scheduling of the ATM cell transmission in each uplink Time-Division Multiple-Access (TDMA) frame is based on a priority scheme. GoS (blocking probability) and QoS (throughput) parameters for Bandwidth Sharing Policy (BSP) are considered and Partial Overlap Link (POL) is implemented. The clustering procedure for the performance analysis of the mobile communication networks and the blocking probability and throughput measurements are introduced as Markov reward models enhanced with Vector Quantification (VQ) and neural modelling. The optimal link occupancy probability distribution is determined using neural network that was trained on the base of Kohonen rules. Simulation and numerical results are shown.

Byline: Timo Koivumaki, Annu Ristola, Manne Kesti This paper studies consumer acceptance of mobile services. The theoretical framework of the study is based on extended Technology Acceptance Model (TAM). The empirical part of the study was conducted in an experimental mobile service environment, SmartRotuaari, which was developed in the University of Oulu's Rotuaari research project. SmartRotuaari is operational at the city centre of Oulu in Northern Finland. Our results show that usefulness, user guidance and support, and user skills are significant factors in explaining the acceptance of mobile services. We also found that usefulness and user-satisfaction are significant predictors of the willingness to recommend the services to others.

Byline: Anna Trifonova, Marco Ronchetti M-learning is currently a rapidly expanding domain. Provoked by the fast advances of mobile technologies, different applications and systems are developed continuously. Here we address the hoarding problem, which is weakly explored before but is a particularly important issue in the mobile domain, and a solution should be included in every system with a large quantity of data. Hoarding is the process of automatically selecting learning content, which is to be prepared and prefetched on the mobile device's local memory for the following offline session. We describe the hoarding problem and the strategy to solve it with the goal of providing an efficient hoarding solution.

Byline: Keng Siau, Hong Sheng, Fiona Nah, Sid Davis Mobile commerce represents a significant development in e-commerce, offering accessibility, ubiquity, mobility, and localisation to users. Despite the potential of mobile commerce, trust is a major obstacle in its adoption and development. Many consumers feel uncomfortable with the idea of conducting commerce over wireless, hand-held devices. The focus of this research is to understand trust in mobile commerce and to identify factors that are important for trust development. The research builds on Siau and Shen's framework which depicts two key factors influencing trust in mobile commerce. This research not only validates and expands on the existing framework, but also provides an expanded conceptual model for future research.

Byline: Minder Chen There is a tremendous amount of interest in developing mobile enterprise computing applications, driven by recent advancements in mobile technologies and standards, as well as an increasing mobile workforce population. However, many enterprises are uncertain of the various options they may have due to the emerging nature of mobile computing technologies. Additionally, they are concerned about the integration of mobile technologies with existing IT infrastructure and applications. In this paper, we propose a methodology to help enterprises develop business strategies and architectures for mobile computing. A generic mobile technical infrastructure is presented to assist enterprises in evaluating and implementing mobile applications. Software standards that may have major impacts on mobile technical architectures and application development are discussed. Finally, the implications of the proposed methodology for mobile computing for practitioners and researchers are discussed in the conclusion.

Byline: Pia Hurmelinna, Jukka Bergman, Ari Jantunen Companies need abilities to sense and seize new opportunities as well as to reconfigure and protect knowledge assets, competences, complementary assets and technologies in order to achieve sustainable competitive advantage. Utilising the scenario process where sharing existing knowledge enhances recognising new possibilities, finding and creating future-oriented knowledge assets can be notably improved. This process produces both tacit and explicit knowledge. Since competitive advantage can only be achieved by using hard-to-imitate scarce assets, creating barriers for imitation becomes essential, especially when codified knowledge is considered. Thus, taking appropriability strategies into account from the very beginning of the scenario process is an essential part of using and creating the dynamic capabilities for the companies participating in the process. In this study, the combination of the scenario process and appropriability strategies is examined in the field of wireless communication technology, and it is illustrated by a case example of varying partners forming a knowledge network.

A possible form for telecommunication industry wide value creation and factors shaping the inter-firm relationships in mobile telecommunications is presented. Further, the factors that will jointly determine corporate strategies and the resulting competitive and informational characteristics of the industry are mentioned.

The study Business Life 2020 written by James Harkin, an expert on social trends, states that most of the UK's offices will become nothing more than lounges containing wireless hotspots. [...]