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Byline: Pruthikrai Mahatanankoon Text messaging is an asynchronous communication tool for both utilitarian and entertainment activities. The purpose of this study is to investigate the self-determined motivation of text messaging behaviours through Self-Determination Theory (SDT). Data collected via a web-based survey were used to examine the effects of autonomy, competence and relatedness on self-determined Short Message Service (SMS). Structural Equation Modelling (SEM) revealed that only competency and relatedness increase self-determined SMS, while autonomy affected it negatively. The result implies that the ability to engage in personal communication and the desire to become socially connected are the essence of SMS internal motivation. This study also suggests that higher self-determined information technology usage reduces freedom to disengage from it and that obligated communication becomes another determining factor of usage. Practitioners and researchers can benefit from these findings by incorporating self-determined usage behaviours into workplay aspects of modern day ubiquitous computing usage.

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: Dong-Hee Shin This study presents a case analysis of a socio-technical framework used to assess the development of 4th generation mobile technology in Korea. Using Actor Network Theory (ANT), this study develops a rich understanding of how 4G will evolve and stabilise in next-generation network environments. ANT provides a framework of ideas for describing the process of technology adoption and for developing stories that explain it. An interpretive case study investigates the complex interaction between the social and technical aspects of 4G by highlighting the co-evolving nature, diversity, and interface that constitute the next-generation network environment. It provides insight into the Korean mobile environment by offering a socio-technical analysis of 4G development and how it involves the dynamics of industry, regulation, and technology. The use of ANT as a framework of analysis reveals a unique set of socio-technical problems, challenges, and opportunities in 4G technology.

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: 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: ThaeMin Lee, JongKun Jun We propose Contextual Perceived Value (CPV) of marketing offer as a new construct that reflects Mobile Commerce (MC)-specific features. The primary contribution of this research is to integrate MC-specific variable (CPV of marketing offer) with TAM (Technology Acceptance Model) to explain MC acceptance. This study also investigated the role of contextual marketing offer in MC acceptance between MC-users and nonusers. The empirical results support the extended TAM in explaining consumers' behavioural intentions to use MC. Specifically, the effect of CPV of marketing offer on the behavioural intention to use MC was greater for MC-nonusers group than for MC-users group.

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.