Mobile Information Systems - Volume 6, issue 1

Authors: You, Ilsun | Hara, Takahiro

Article Type: Research Article

DOI: 10.3233/MIS-2010-0089

Citation: Mobile Information Systems, vol. 6, no. 1, pp. 1-3, 2010

Authors: Hara, Takahiro | Nishio, Shojiro

Article Type: Research Article

Abstract: In a mobile ad hoc network, consistency management of data operations on replicas is a crucial issue for system performance. In our previous work, we classified several primitive consistency levels according to the requirements from applications and provided protocols to realize them. In this paper, we assume special types of applications in which the instances of each data item can be partitioned and propose two consistency management protocols which are combinations of an escrow method and …our previously proposed protocols. We also report simulation results to investigate the characteristics of these protocols in a mobile ad hoc network. From the simulation results, we confirm that the protocols proposed in this paper drastically improve data availability and reduce the traffic for data operations while maintaining the global consistency in the entire network. Show more

Keywords: Consistency management, mobile ad hoc network, data replication, escrow

DOI: 10.3233/MIS-2010-0090

Citation: Mobile Information Systems, vol. 6, no. 1, pp. 5-26, 2010

Authors: Caballé, Santi | Xhafa, Fatos | Barolli, Leonard

Article Type: Research Article

Abstract: Mobile collaborative learning is considered the next step of on-line collaborative learning by incorporating mobility as a key and breakthrough requirement. Indeed, the current wide spread of mobile devices and wireless technologies brings an enormous potential to e-learning, in terms of ubiquity, pervasiveness, personalization, flexibility, and so on. For this reason, Mobile Computer-Supported Collaborative Learning has recently grown from a minor research field to significant research projects covering a fairly variety of …formal and specially informal learning settings, from schools and universities to workplaces, museums, cities and rural areas. Much of this research has shown how mobile technology can offer new opportunities for groups of learners to collaborate inside and beyond the traditional instructor-oriented educational paradigm. However, mobile technologies, when specifically applied to collaborative learning activities, are still in its infancy and many challenges arise. In addition, current research in this domain points to highly specialized study cases, uses, and experiences in specific educational settings and thus the issues addressed in the literature are found dispersed and disconnected from each other. To this end, this paper attempts to bridge relevant aspects of mobile technologies in support for collaborative learning and provides a tighter view by means of a multidimensional approach. Show more

Keywords: Mobile collaborative learning, mobile technologies, ubiquity, pervasiveness, constructivism, behaviorism, situated learning, social learning

DOI: 10.3233/MIS-2010-0091

Citation: Mobile Information Systems, vol. 6, no. 1, pp. 27-47, 2010

Authors: Durresi, Arjan | Zhang, Ping | Durresi, Mimoza | Barolli, Leonard

Article Type: Research Article

Abstract: Multi domain networks can be used in several scenarios including military, enterprize networks, emergency networks and many other cases. In such networks, each domain might be under its own administration. Therefore, the cooperation among domains is conditioned by individual domain policies regarding sharing information, such as network topology, connectivity, mobility, security, various service availability and so on. We propose a new architecture for Heterogeneous Multi Domain (HMD) networks, in which one the operations are …subject to specific domain policies. We propose a hierarchical architecture, with an infrastructure of gateways at highest-control level that enables policy based interconnection, mobility and other services among domains. Gateways are responsible for translation among different communication protocols, including routing, signalling, and security. Besides the architecture, we discuss in more details the mobility and adaptive capacity of services in HMD. We discuss the HMD scalability and other advantages compared to existing architectural and mobility solutions. Furthermore, we analyze the dynamic availability at the control level of the hierarchy. Show more

Keywords: Network architecture, mobility, policy based networking, heterogeneous networks

DOI: 10.3233/MIS-2010-0092

Citation: Mobile Information Systems, vol. 6, no. 1, pp. 49-63, 2010

Authors: Tang, Feilong | You, Ilsun | Guo, Minyi | Guo, Song | Zheng, Long

Article Type: Research Article

Abstract: Mobile and wireless networks are the integrant infrastructure of mobile and pervasive computing that aims at providing transparent and preferred information and services for people anytime anywhere. In such environments, end-to-end network bandwidth is crucial to improve user's transparent experience when providing on-demand services such as mobile video playing. As a result, powerful computing power is required for networked nodes, especially for routers. General-purpose processors cannot meet such requirements due to their …limited processing ability, and poor programmability and scalability. Intel's network processor IXP is specially designed for fast packet processing to achieve a broad bandwidth. IXP provides a large number of registers to reduce the number of memory accesses. Registers in an IXP are physically partitioned as two banks so that two source operands in an instruction have to come from the two banks respectively, which makes the IXP register allocation tricky and different from conventional ones. In this paper, we investigate an approach for efficiently generating balanced bipartite graph and register allocation algorithms for the dual-bank register allocation in IXPs. The paper presents a graph uniform 2-way partition algorithm (FPT), which provides an optimal solution to the graph partition, and a heuristic algorithm for generating balanced bipartite graph. Finally, we design a framework for IXP register allocation. Experimental results demonstrate the framework and the algorithms are efficient in register allocation for IXP network processors. Show more

Keywords: Register allocation, network processor, bipartite graph, mobile and wireless network, register bank

DOI: 10.3233/MIS-2010-0093

Citation: Mobile Information Systems, vol. 6, no. 1, pp. 65-83, 2010

Authors: Chang, Hang Bae | Kwon, Hyuk Jun | Kang, Jong Gu

Article Type: Research Article

Abstract: The commensurate number of the attacks and infringement targeting a vulnerability of the game service has been increasing constantly, due to the dramatic growth and expansion of the impact of the game industry. However, there exist no subsequent researches for the differentiated technology, which is to prevent the reverse function of the game service. Therefore, in this study, we examined the current status of infringement toward online game services which are provided in the market currently …and designed the proper technical measures ('Software Tamper Resistance') for a manipulation of the game service which is the most vulnerable part. In detail, we have encrypted an execution file and decrypted it in real time process. After that we implemented antibebugging, disassemble, and antidump technology. Show more

Keywords: Mobile game security, software tamper resistance, debugging, disassemble, memory dump

DOI: 10.3233/MIS-2010-0094

Citation: Mobile Information Systems, vol. 6, no. 1, pp. 85-105, 2010

Authors: Kim, HyunGon | Lee, Jong-Hyouk

Article Type: Research Article

Abstract: Wireless communication service providers have been showing strong interest in Proxy Mobile IPv6 for providing network-based IP mobility management. This could be a prominent way to support IP mobility to mobile nodes, because Proxy Mobile IPv6 requires minimal functionalities on the mobile node. While several extensions for Proxy Mobile IPv6 are being developed in the Internet Engineering Task Force, there has been little attentions paid to developing efficient authentication mechanisms. An authentication scheme for a …mobility protocol must protect signaling messages against various security threats, e.g., session stealing attack, intercept attack by redirection, replay attack, and key exposure, while minimizing authentication latency. In this paper, we propose a Diffie-Hellman key based authentication scheme that utilizes the low layer signaling to exchange Diffie-Hellman variables and allows mobility service provisioning entities to exchange mobile node's profile and ongoing sessions securely. By utilizing the low layer signaling and context transfer between relevant nodes, the proposed authentication scheme minimizes authentication latency when the mobile node moves across different networks. In addition, thanks to the use of the Diffie-Hellman key agreement, pre-established security associations between mobility service provisioning entities are not required in the proposed authentication scheme so that network scalability in an operationally efficient manner is ensured. To ascertain its feasibility, security analysis and performance analysis are presented. Show more

Keywords: PMIPv6, NETLMM, authentication, security

DOI: 10.3233/MIS-2010-0095

Citation: Mobile Information Systems, vol. 6, no. 1, pp. 107-121, 2010