共查询到20条相似文献,搜索用时 13 毫秒
1.
We propose an integrated resource management approach that can be implemented in next generation wireless networks that support multimedia services (data, voice, video, etc.). Specifically, we combine the use of position-assisted and mobility predictive advanced bandwidth reservation with a call admission control and bandwidth reconfiguration strategy to support flexible QoS management. We also introduce a mobile agent based framework that can be used to carry out the functions of geolocation and of the proposed resource management in wireless networks. A model is also developed to obtain the optimal location information update interval in order to minimize the total cost of the system operation. The comparison of the achievable performance results of our proposed scheme with the corresponding results of a conventional system that supports advanced bandwidth reservation only, as means of supporting the QoS requirements, demonstrate that our integrated scheme can alleviate the problem of overreservation, support seamless operation throughout the wireless network, and increase significantly the system capacity. 相似文献
2.
Linoh A. Magagula H. Anthony Chan Olabisi E. Falowo 《Wireless Communications and Mobile Computing》2012,12(16):1414-1428
Next generation wireless networks (NGWN) will be an integration of heterogeneous wireless access networks that will interwork over an IP‐based infrastructure. This all‐IP vision has led to the development of handover mechanisms to support seamless mobility for active network services among the different interworking wireless networks in order to ensure network access ubiquity in NGWN. These handover mechanisms need to ensure that mobile devices continue to receive ongoing communication without any noticeable disruption during handover events among the heterogeneous networks. This paper gives a qualitative and quantitative review of current handover approaches of IP mobility management protocols for NGWN with an objective to introduce a new way of further optimizing the handover performance. In particular, the paper focuses on handover approaches of mobile IPv6 (MIPv6) based mobility management protocols. Thus, the need, benefits, and limitations of these handover approaches are explored. Thereafter, dynamic handover coordination is introduced as a new viable solution that exploits the benefits and mitigates the limitations of these handover approaches hence improving handover performance in terms of handover delay, packet loss, and signaling overhead. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
3.
Luan Huang Yajian Liu Shyamalie Thilakawardana Rahim Tafazolli 《Communications Letters, IEEE》2006,10(12):822-824
This letter addresses the user assignment problem for multimedia streaming applications in heterogeneous multicast-enabled wireless networks using a network-centric strategy. The optimal problem is mathematically formulated and proven to be non-deterministic polynomial-time (NP)-hard. An efficient heuristic algorithm is then proposed to find sub-optimal solutions in practical systems. Simulation results demonstrate the improved performance of this heuristic in comparison to a conventional user-centric algorithm 相似文献
4.
As many geo-located Web services will be deployed in the future, mobile clients will be interested in locating a specific application server based on requirements such as proximity, service cost per location area, bandwidth, and server utilization rates. This paper presents a middleware system called GLWSA (Geo-Located Web Services Architecture) that aims to satisfy these requirements in addition to providing a thematic factorization of common location functions in order to locate mobile clients. The GLWSA supports a set of GLWSMs (Geo-Located Web Services Manager) distributed over the mobile network. It defines protocols to discover and inform a Supplier Application Server (SAS) to migrate the service execution (from a specific client) to the nearest SAS based on the client's location. This architecture is suitable to assist mobile clients to discover the geo-located Web services and to maintain the service execution closest to their location. 相似文献
5.
Dr. techn. Dr. tekn. h.c. Prof. Emeritus J?rgen Bach Andersen M.Sc. Ph.D. Prof. Gert Fr?lund Pedersen 《e & i Elektrotechnik und Informationstechnik》2012,129(6):383-386
In future mobile communications many antennas will coexist on the device. This creates a number of problems related to bandwidth, efficiency, and correlation. Remedies are discussed in the paper, and attention is called to the promising area of adaptive matching, which also can solve problems related to the user. 相似文献
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Employees in today’s enterprises are requesting their employers to allow them to work in a flexible manner. Work is no longer
a place to go to but an activity to be undertaken. With developments in technology, the activity can be undertaken whenever
and wherever it is convenient for the employees. Increasing demands by employees to be able to work in this way creates a
tension within the enterprise as CIOs and finance officers strive to manage the costs and the infrastructure required to support
this way of working. Over time, this situation will change as technology allows users to roam securely and seamlessly between
networks accessing the required applications and information from a single suitably enabled device. This will tend to reduce
the underlying costs as the best connection can be used. Service management will remain a challenge but become a better understood
problem as the ’stove-pipe’ nature of current solutions is removed. For this change to be brought about, some enabling technologies
have to be put in place.
This paper considers issues surrounding next generation mobile solutions and shows how converged services can be used to deliver
the vision of being able to work from any place, at any time. Consideration is given to how roaming from fixed to wireless
networks can be achieved by reusing already established authentication principles that are now deployed in wide area wireless
networks. In order to do this, open methods of managing user identity need to be devised and implemented and approaches to
this are also discussed. The paper concludes with a consideration of some of the research challenges that remain to be solved.
HP 相似文献
8.
Simulation has become an indispensable tool in the design and evaluation of mobile systems. By using mobility models that describe constituent movement, one can explore large systems, producing repeatable results for comparison between alternatives. In this paper, we show that a large class of mobility models - including all those in which nodal speed and distance or destination are chosen independently - have a transient period in which the average node speed decreases until converging to some long-term average. This speed decay provides an unsound basis for simulation studies that collect results averaged over time, complicating the experimental process. In this paper, we derive a general framework for describing this decay and apply it to a number of cases. Furthermore, this framework allows us to transform a given mobility model into a stationary one by initializing the simulation using the steady-state speed distribution and using the original speed distribution subsequently. This transformation completely eliminates the transient period and the decay in average node speed and, thus, provides sound models for the simulation of mobile systems. 相似文献
9.
《Communications Magazine, IEEE》2006,44(9):62-71
10.
Salsano S. Polidoro A. Mingardi C. Niccolini S. Veltri L. 《Wireless Communications, IEEE》2008,15(2):92-99
The ITU-T definition of next generation networks includes the ability to make use of multiple broadband transport technologies and to support generalized mobility. Next generation networks must integrate several IP-based access technologies in a seamless way. In this article, we first describe the requirements of a mobility management scheme for multimedia real-time communication services; then, we report a survey of the mobility management schemes proposed in the recent literature to perform vertical handovers between heterogeneous networks. Based on this analysis, we propose an application-layer solution for mobility management that is based on the SIP protocol and satisfies the most important requirements for a proper implementation of vertical handovers. We also implemented our proposed solution, testing it in the field, and proving its overall feasibility and its interoperability with different terminals and SIP servers. 相似文献
11.
Perera E. Boreli R. Herborn S. Georgiades M. Eisl J. Hepworth E. 《Wireless Communications, IEEE》2008,15(2):8-16
The future Internet will need to cater to an increasing number of mobile devices and mobile networks, roaming across different access networks and trust domains. In addition, various limitations imposed by the end user, service provider, or network operator agreements and preferences will need to be considered. A plethora of mobility management protocols have been proposed to handle different and mostly limited sets of these mobility requirements. In this article we make the case for coexistence of mobility protocols in order to support the large range of mobility scenarios possible in future all-IP networks. This coexistence takes the form of a mobility toolbox that enables mobility handling mechanisms to be selected according to the context. We then present a design for the mobility toolbox as a component of the ambient networks architecture, including a simplified mobility tool interface toward protocol modules, and show how it meets the requirements of future all-IP networks. We further demonstrate the feasibility and performance gains of the mobility toolbox architecture with a prototype implementation based on network mobility. 相似文献
12.
Tobias Buehler 《电子产品世界》2005,(1):113-115
10多年前,当第一代蜂窝电话出现时,采用了许多分立功率器件.第一代手机显得很笨重,高功耗使得待机时间和通话时间都很短.为了响应客户对外形更小,性能更高的无线电子设备不断增长的需求,工程师发展了许多先进的设计技术.这些技术既可缩小印刷电路板(PCB)尺寸,又可以提供更快更高效的性能. 相似文献
13.
Roland Bless Joachim Hillebrand Christian Prehofer Martina Zitterbart 《Wireless Personal Communications》2007,43(3):817-835
The coupling of signaling protocols for mobility management and resource reservation plays an important role to achieve Quality-of-Service
(QoS) in wireless environments. When performing a handover, request and allocation of resources have to be done in the shortest
possible time to avoid disruptions for the user service. Therefore, it is preferable to ensure resource availability in advance,
which we call anticipated handover. This approach for providing seamless handovers in turn poses challenges for the overall
design of the QoS architecture and its associated QoS signaling protocol. This article describes the design, implementation,
and evaluation of a comprehensive QoS architecture and a suitable QoS signaling protocol. It discusses intrinsic problems
of reservations in IP based networks such as session ownership as well as a number of protocol design issues regarding the
integration of QoS signaling with other protocols, such as Mobile IP. In particular, we define an end-to-end QoS architecture
and a mobility-aware reservation signaling protocol Mobility Aware Reservation Signaling Protocol (MARSP) that supports anticipated
handover, thus enabling seamless services over heterogeneous wireless access networks. The presented architecture and protocol
were implemented and evaluated by measurements. They show that anticipated handovers not only outperform hard handovers regarding
handover latency, but that they also provide functional and robustness advantages.
Authors Hillebrand and Prehofer changed their affiliation in the meantime, the work described in this paper was carried out
during their employment at DoCoMo Communications Laboratories Europe. 相似文献
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On the predictability of next generation mobile network traffic using artificial neural networks 下载免费PDF全文
I. Loumiotis E. Adamopoulou K. Demestichas T. Stamatiadi M. Theologou 《International Journal of Communication Systems》2015,28(8):1484-1492
Though the introduction of the new 4th Generation mobile access technologies promises to satisfy the increasing bandwidth demand of the end‐users, it poses in parallel the need for novel resource management approaches at the side of the base station. To this end, schemes that try to predict the forthcoming bandwidth demand using supervised learning methods have been proposed in the literature. However, there are still open issues concerning the training phase of such methods. In the current work, the authors propose a novel scheme that dynamically selects a proper training set for artificial neural network prediction models, based on the statistical characteristics of the collected data. It is demonstrated that an initial statistical processing of the collected data and the subsequent selection of the training set can efficiently improve the performance of the prediction model. Finally, the proposed scheme is validated using network traffic collected by real, fully operational base stations. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
16.
文章首先介绍了下一代网络(NGN)中的核心--IP多媒体子系统(IMS)及其体系结构的特点,说明了它适合于网络和服务融合的原因,然后分析了利用IMS架构开展的业务,以及一种基于IMS的多业务移动平台,最后结合IP电视(IPTV)的技术特点以及融合中的问题,提出了一种将IPTV应用于IMS移动平台的方案. 相似文献
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A mobility measure for mobile ad hoc networks 总被引:1,自引:0,他引:1
A mobility measure for mobile ad hoc networks is proposed that is flexible because one can customize the definition of mobility using a remoteness function. The proposed measure is consistent because it has a linear relationship to the rate at which links are established or broken for a wide range of mobility scenarios, where a scenario consists of the choice of mobility model, the physical dimensions of the network, the number of nodes. This consistency is the strength of the proposed mobility measure because the mobility measure reliably represents the link change rate regardless of network scenarios. 相似文献
19.
Europe's third-generation mobile communication system will transform the capabilities of cellular networks. The authors describe some of the implications for users, network operators and would-be licence holders of UMTS (Universal Mobile Telephone System) 相似文献
20.
Heterogeneity of connection technologies and nodes mobility open new challenges in home networks control strategies. Moreover, user’s needs are changing towards applications requiring high transmission speeds such as 3D gaming, enhanced interactivity and high definition video. Each of those applications puts several constraints on the network capabilities to guarantee requirements on the Quality of Service. In this paper we introduce an innovative concept based on fast load balancing algorithm operating on top of a convergence layer, in order to rapidly react to network changes and contemporaneously to satisfy strict application demands. We formulated the load balancing problem as a Multi-Commodity Flow and resolved it with a column generation approach using Lagrangian Relaxation and Dijkstra algorithm. The load balancing problem computational complexity is decreased with respect to state of the art load balancing solutions based on linear programming techniques. Proof of concept simulation results are reported. 相似文献