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Application of Particle Swarm Optimizer on Load Distribution for Hybrid Network Selection Scheme in Heterogeneous Wireless Networks  [PDF]
Yoke Chek Yee,Su Wei Tan,Heng Siong Lim,Su Fong Chien
ISRN Communications and Networking , 2012, DOI: 10.5402/2012/340720
Abstract: Mobile terminal with multiradios is getting common nowadays with the presence of heterogeneous wireless networks such as 3G, WiMAX, and WiFi. That Network selection mechanism plays an important role in ensuring mobile terminals are always connected to the most suitable network. In this paper, we introduce and evaluate the performance of load distribution model to facilitate better network selection. We focus on the optimization of network resource utilization using the particle swarm optimizer (PSO) with the objective to distribute the system load according to the various conditions of the heterogeneous networks in order to achieve minimum system cost. Simulation results showed that the proposed approach outperformed the conventional iterative algorithm by a cost improvement of 7.24% for network size of 1000 mobile terminals using 10 particles. 1. Introduction There has been a drastic and huge development in both mobile technologies such as global system for mobile communications (GSM), general packet radio service (GPRS), and universal mobile telecommunications system (UMTS) which promise high mobility, wide coverage, but low bandwidth rate, as well as on other wireless technologies such as wireless fidelity (WiFi) and worldwide interoperability for microwave access (WiMAX) which offer faster rates at lower cost but suffered from limited mobility and coverage. The different characteristics of these mobile/wireless technologies help compensating for coverage, mobility, bandwidth, and speed, and this helps meeting the requirements due to the increase of user demands in a complementary manner [1]. It is therefore believed that the future network infrastructure will consist of coverage overlapping of heterogeneous networks [2], where multiradios mobile devices could seamlessly and conveniently access to any network in a ubiquitous manner according to the concept of always best connected (ABC) [3]. The challenge to ubiquitous access to any network lies on an efficient and effective mobility management framework which initially focused on enabling seamless vertical handover across heterogeneous networks due to user mobility. Recently, vertical handover is also considered as proactive means to system performance improvement [4, 5]. Realizing a seamless and ubiquitous network access heavily depends on the second phase in vertical handover process called handover decision, which determines and selects one of the most optimal alternative networks to connect to. The selection of network is usually based on parameters such as signal strength, network conditions,
Framework for Key Management Scheme in Heterogeneous Wireless Sensor Networks
Kamal Kumar,A. K. Verma,R. B. Patel
Journal of Emerging Technologies in Web Intelligence , 2011, DOI: 10.4304/jetwi.3.4.286-296
Abstract: Ubiquitous computing environments find their practical implementations through wireless sensor networks, which sense a relationship among themselves and the environment. Presently devised key management schemes are classified namely for homogeneous environments, or heterogeneous environments. In this paper, we propose a deployment conscious security framework supporting, a shift of complex operations to more capable nodes of heterogeneous environment and relieving resource constrained generic sensor nodes of major activities. We introduced a concept of deployment knowledge independent group key generation using a special kind of heterogeneity-multilevel transmission. Performance of proposed key management schemes is evaluated across relevant matrices and concluded to be satisfactory. Findings show that asymmetric key cryptography is comparatively more demanding in resources than symmetric version but ensures maximum security. Through our work we able to conclude that a hybrid of asymmetric and symmetric key cryptography best suits heterogeneous environments.
Ubiquitous HealthCare in Wireless Body Area Networks  [PDF]
N. A. Khan,N. Javaid,Z. A. Khan,M. Jaffar,U. Rafiq,A. Bibi
Computer Science , 2012,
Abstract: Recent advances in wireless communications, system on chip and low power sensor nodes allow realization of Wireless Body Area Networks (WBANs).WBANs comprise of tiny sensors, which collect information of a patient's vital signs and provide a real time feedback. In addition,WBANs also support many applications including ubiquitous healthcare, entertainment, gaming, military, etc. Ubiquitous healthcare is required by elderly people to facilitate them with instant monitoring anywhere they move around. In this paper, we provide a survey on different architectures used in WBANs for ubiquitous healthcare monitoring. Different standards and devices used in these architectures are also discussed in this paper. Finally, path loss in WBANs and its impact on communication is presented with the help of simulations performed for different models of In-Body communication and different factors (such as, attenuation, frequency, distance etc) influencing path loss in On-Body communications.
A Fuzzy Preprocessing Module for Optimizing the Access Network Selection in Wireless Networks  [PDF]
Faisal Kaleem,Abolfazl Mehbodniya,Kang K. Yen,Fumiyuki Adachi
Advances in Fuzzy Systems , 2013, DOI: 10.1155/2013/232198
Abstract: A heterogeneous wireless network is characterized by the presence of different wireless access technologies that coexist in an overlay fashion. These wireless access technologies usually differ in terms of their operating parameters. On the other hand, Mobile Stations (MSs) in a heterogeneous wireless network are equipped with multiple interfaces to access different types of services from these wireless access technologies. The ultimate goal of these heterogeneous wireless networks is to provide global connectivity with efficient ubiquitous computing to these MSs based on the Always Best Connected (ABC) principle. This is where the need for intelligent and efficient Vertical Handoffs (VHOs) between wireless technologies in a heterogeneous environment becomes apparent. This paper presents the design and implementation of a fuzzy multicriteria based Vertical Handoff Necessity Estimation (VHONE) scheme that determines the proper time for VHO, while considering the continuity and quality of the currently utilized service, and the end-users' satisfaction. 1. Introduction During recent years, the need for global connectivity to access different types of services at any place and any time has significantly increased. The latest innovations [1] in wireless access technology provide uninterrupted on-demand services, such as real-time multimedia, which are independent of device type, locations, and available networks [2]; the ultimate goal is to maintain a satisfactory end-user experience by providing the necessary quality and continuity of the currently utilized service in a cost-efficient manner. A heterogeneous wireless network comprises of different wireless networks including IEEE 802.15 based Wireless Personal Area Network (WPAN), IEEE 802.11 based Wireless Local Area Networks (WLAN), IEEE 802.16 based Wireless Metropolitan Area Network (WMAN), different types of cellular technologies such as Global System of Mobile Communication (GSM) and Universal Mobile Telecommunication System (UMTS), Vehicular Ad hoc Network (VANET), and satellite networks. To provide seamless mobility and convergence, integration of these diverse wireless networks is required. A multimodal Mobile Station (MS), in the presence of these integrated networks with overlapping coverage, can connect to any of these wireless access technologies. An MS, in a heterogeneous wireless network, switches its current Point of Attachment (PoA) to a new wireless network using a process called Vertical Handoff (VHO). These VHOs are required to maintain the continuity and quality of the current session
Ubiquitous robust communications for emergency response using multi-operator heterogeneous networks  [cached]
Fragkiadakis Alexandros,Askoxylakis Ioannis,Tragos Elias,Verikoukis Christos
EURASIP Journal on Wireless Communications and Networking , 2011,
Abstract: A number of disasters in various places of the planet have caused an extensive loss of lives, severe damages to properties and the environment, as well as a tremendous shock to the survivors. For relief and mitigation operations, emergency responders are immediately dispatched to the disaster areas. Ubiquitous and robust communications during the emergency response operations are of paramount importance. Nevertheless, various reports have highlighted that after many devastating events, the current technologies used, failed to support the mission critical communications, resulting in further loss of lives. Inefficiencies of the current communications used for emergency response include lack of technology inter-operability between different jurisdictions, and high vulnerability due to their centralized infrastructure. In this article, we propose a flexible network architecture that provides a common networking platform for heterogeneous multi-operator networks, for interoperation in case of emergencies. A wireless mesh network is the main part of the proposed architecture and this provides a back-up network in case of emergencies. We first describe the shortcomings and limitations of the current technologies, and then we address issues related to the applications and functionalities a future emergency response network should support. Furthermore, we describe the necessary requirements for a flexible, secure, robust, and QoS-aware emergency response multi-operator architecture, and then we suggest several schemes that can be adopted by our proposed architecture to meet those requirements. In addition, we suggest several methods for the re-tasking of communication means owned by independent individuals to provide support during emergencies. In order to investigate the feasibility of multimedia transmission over a wireless mesh network, we measured the performance of a video streaming application in a real wireless metropolitan multi-radio mesh network, showing that the mesh network can meet the requirements for high quality video transmissions.
HETEROGENEOUS PROTOCOLS FOR INCREASING LIFETIME OF WIRELESS SENSOR NETWORKS  [cached]
Samayveer Singh
Journal of Global Research in Computer Science , 2011,
Abstract: In this paper, the heterogeneous energy-efficient data gathering protocols for lifetime of wireless sensor networks have been reported. The main requirements of wireless sensor network are to prolong the network lifetime and energy efficiency. Here, Heterogeneous - SEP: A Stable Election Protocol for clustered heterogeneous (H-SEP) for Wireless Sensor Network has been proposed to prolong the network lifetime. In this paper, the impacts of heterogeneity in terms of node energy in wireless sensor networks have been mentioned. Finally the simulation result demonstrates that H-SEP achieves longer lifetime and more effective data packets in comparison with the SEP and LEACH protocol.
Enabling Roaming in Heterogeneous Multi-Operator Wireless Networks  [cached]
Oscar Salazar Gaitán,Philippe Martins,Jacques Demerjian,Samir Tohmé
Journal of Communications , 2007, DOI: 10.4304/jcm.2.4.18-28
Abstract: Next generation wireless networks will take advantage of the popularity and the data rates offered byunlicensed wireless networks to enhance cellular services. Nowadays, it is not surprising to see heterogeneous wireless networks coexisting on a daily basis i.e. UMTS, WiFi, and WiMAX. Unfortunately, technical issues and the lack of roaming agreements between network operators prevent interoperability. One of the goals of next generation wireless networks is to enable service mobility between heterogeneous wireless networks, thus we present in this article a SIP-based roaming architecture to enable service mobility in heterogeneous multi-operator wireless networks. Our objective is to establish mutual trust between cellular network operators and unlicensed wireless networks through a efficient SLA monitoring and enforcement and brokerbased access control. All this, with minimal changes in current wireless network architectures.
An Efficient Architecture in Next Generation Wireless Networks
Anjali Rasal,Dr. S. D. Lokhande
International Journal of Engineering Science and Technology , 2010,
Abstract: Next-Generation wireless networks are proposed to achieve the goal of ubiquitous wireless networking by utilizing heterogeneous networks. The performance of Location management scheme directly affects the overall performance of NGWN at large. This affect significantly impacts on the signalling traffic in terms of the database’s waiting time, query and update response time, processing power, bandwidth requirements etc. in the global roaming. Several architectures have been proposed to reduce such traffic. We have analyzed the impactof different system parameters with different architectures, one is multi-tier HLR and another is WING architecture. The performance of these architectures is analyzed with parameters such as location management cost, paging cost, query response time etc. The result of this work shows that WING architecture enhances the location management scheme than MHLR architecture during heterogeneous system roaming process. Thus in global roaming WING architecture can improve the network performance significantly in terms of signalling traffic.
Connectivity of Heterogeneous Wireless Networks  [PDF]
Wei Ren,Qing Zhao,Ananthram Swami
Computer Science , 2009,
Abstract: We address the connectivity of large-scale ad hoc heterogeneous wireless networks, where secondary users exploit channels temporarily unused by primary users and the existence of a communication link between two secondary users depends on not only the distance between them but also the transmitting and receiving activities of nearby primary users. We introduce the concept of connectivity region defined as the set of density pairs -- the density of secondary users and the density of primary transmitters -- under which the secondary network is connected. Using theories and techniques from continuum percolation, we analytically characterize the connectivity region of the secondary network and reveal the tradeoff between proximity (the number of neighbors) and the occurrence of spectrum opportunities. Specifically, we establish three basic properties of the connectivity region -- contiguity, monotonicity of the boundary, and uniqueness of the infinite connected component, where the uniqueness implies the occurrence of a phase transition phenomenon in terms of the almost sure existence of either zero or one infinite connected component; we identify and analyze two critical densities which jointly specify the profile as well as an outer bound on the connectivity region; we study the impacts of secondary users' transmission power on the connectivity region and the conditional average degree of a secondary user, and demonstrate that matching the interference ranges of the primary and the secondary networks maximizes the tolerance of the secondary network to the primary traffic load. Furthermore, we establish a necessary condition and a sufficient condition for connectivity, which lead to an outer bound and an inner bound on the connectivity region.
Mobile identity management system in heterogeneous wireless networks
ukasz Kucharzewski, Zbigniew Kotulski
Annales UMCS, Informatica , 2011, DOI: 10.2478/v10065-011-0016-5
Abstract: Heterogeneous wireless networks increasingly encroach on our lives. Various technologies and mobile applications more often than usual are now used by mobile users. Intensive development of mobile networks not only sets new standards for radio, but increasingly focuses on providing security for traffic transmitted in wireless networks. Security in wireless networks has never been the primary objective of the designers of new network standards. The reason for this fact were both low hardware resources of equipment, but also lack of awareness of users about the potential vulnerabilities. Creating a secure, independent of network architecture solutions effectively raising the level of security of transmitted data between end users is the main priority of our research. Current wireless security solutions do not provide sufficient protection of the integrity, confidentiality of data, are not designed to operate in heterogeneous networks, or are too complex to implement. Both networks WiMAX, LTE and WiFi, there are methods that protect the resources in these networks, but they are not consistent with each other. The proposed security system requires the use of mobile version of the PKI to verify the identity of mobile users. Mobile PKI center is an innovative solution, not yet introduced for casual use. Such a solution in heterogeneous wireless networks is a fast, secure and transparent to transmission medium. Designing secure and efficient authentication protocols to enable fast connections to the heterogeneous network is challenging. In the proposed system in this paper, the users authenticate their identity digital certificates that are issued by a trusted third party (CA). PKI uses the algorithms based on elliptic curves. Advantages of elliptic curves in mobile environment will be particularly evident. This ensures adequate protection of data in a heterogeneous networks. In this system, it is possible to implement many new secure services for end users secure email, secure chat, secure remote access.
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