共查询到20条相似文献,搜索用时 10 毫秒
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鉴权管理是移动通信移动管理中非常重要的技术,其策略的选择将直接影响网络中各网元的信令负荷。本文主要讨论移动通信系统前向指针位置管理策略中的鉴权管理。当用户在远离其HLR的不同VLR对应覆盖区域移动时,系统通过向其原VLR索取剩余鉴权数据或向其HLR申请新鉴权数据来实现用户的鉴权管理。通过鉴权开销及被呼处理时延等指标的分析,本文提出的鉴权管理算法较适合于CMR较小的MS鉴权管理;当MS的CMR增大时,本文提出的鉴权管理算法与二层管理策略如GSM或IS-41移动系统的开销及时延等指标逐渐接近。 相似文献
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Wireless Networks - In mobile social networks, forwarding is a challenging problem since there may be no end-to-end paths. Existing schemes using overlays are not applicable to pure mobile social... 相似文献
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Marques V. Costa X.P. Aguiar R.L. Liebsch M. Duarte A.M.O. 《Selected Areas in Communications, IEEE Journal on》2005,23(11):2138-2151
This paper presents a Mobile IPv6-based overlay network architecture for heterogeneous environments, designed entirely based on IPv6, that aims to be implemented seamlessly irrespectively of the supporting network infrastructure. All transmission technologies are handled at the physical and data-link layers, imposing IPv6-based protocols for all higher layer communications and signaling. The architecture builds on Mobile IPv6 including improved fast handover, and integrates quality-of-service and authentication, authorization, accounting, and charging control per user. The most critical issues of the proposed architecture, mainly related to the handover process, were subject of a performance evaluation via ns-2 simulations. Finally, a field trial of the system was implemented, overlaying part of the GEANT infrastructure between Madrid and Stuttgart, which results are presented here. 相似文献
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Xiaonan Wang Shan Zhong 《AEUE-International Journal of Electronics and Communications》2013,67(5):414-425
The paper proposes a hierarchical scheme on implementing all-IP communication between wireless sensor networks and IPv6 networks. The paper proposes the cluster-tree architecture for all-IP wireless sensor networks which is consistent with the IPv6 Internet architecture. Based on the cluster-tree architecture, the paper proposes the hierarchical IPv6 address configuration algorithm where the IPv6 configuration for cluster members in different clusters can be performed simultaneously, so the IPv6 configuration delay is shortened. Based on the proposed cluster-tree architecture and the IPv6 address configuration algorithm, the paper proposes the hierarchical routing scheme in the link layer where the intermediate nodes only need to deal with the frame header in the link layer without processing the headers in the above layers, so the routing delay is shortened and the power consumption is reduced. From both theoretical perspective and simulative perspectives, the paper analyze the performance parameters of the proposed scheme. And the data results show that the performance of the proposed scheme is better. 相似文献
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《中国邮电高校学报(英文版)》2008
In order to reduce the cost and decrease the delay caused by combining the AAA function while guaranteeing the fast handover performance, we bring out an enhanced secure fast handover scheme. Our research focuses on improving the security and reducing the delay during the handover process of mobile IPv6, the most important thing is to minimize the authentication latency in AAA processing. According to the scheme referred above, the performance evaluation is analyzed in terms of pedestrian and vehicle, and the results of simulation show that the proposed mechanism reduces the handoff and authentication latency evidently compared to the previous simple traditional combination modeling. 相似文献
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Sun-Kyum Kim Ji-Hyeun Yoon JunYeop Lee Gi-Young Jang Sung-Bong Yang 《Wireless Networks》2016,22(2):537-552
Most schemes in mobile social networks (MSNs) assume that nodes simply forward messages without considering selfishness. We therefore first devise social preference-based selfishness for MSNs by which nodes decide to drop or keep (forward) and replace messages to save buffer space according to the message preference and the communities of nodes. We then propose a novel cooperative forwarding scheme for social preference-based selfishness in MSNs, the social preference-aware forwarding scheme (SPF) incorporates the proposed message forwarding scheme and a buffer replacement policy for the message preference. It takes advantage of social information with the home-cell community-based mobility model. Considering the contact probability and buffer replacement policy for the message preferences, SPF, therefore, efficiently delivers messages to the destination by reflecting the degree of selfishness to which nodes cooperatively manage their buffer spaces and how frequently and how recently they meet. Consequently, all nodes can cooperatively drop or keep (forward) and replace the messages in the buffer spaces for the message preferences in SPF. SPF outperforms Epidemic, PRoPHET, and SimBet in terms of delivery ratio, network traffic, buffer space, hop count, and replacement frequency. 相似文献
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代理移动IPv6(PMIPv6)是一种基于网络的移动性管理协议。在进行切换的时候,该协议虽在MIPv6的基础上有效地降低了切换延迟,但仍可进行更有效地调整以进一步降低切换延迟。文中提出在原有PMIPv6的基础上,将切换过程中的移动节点的身份认证和移动接入网关在本地移动锚点的注册同步起来,即AR-PMIPv6,引入有效地双缓存机制避免接收数据的丢失和乱序问题,降低了切换延迟和信令开销。实验仿真可知,通过认证注册同步的过程后,AR-PMIPv6在原有PMIPv6的基础上有效地降低了切换延迟,对网络服务质量有显著的提高。 相似文献
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Excellent handover performance is essential for deploying real time applications over wireless Internets. In this paper, this study present a novel handover scheme for Mobile IPv6. The proposed scheme is based on an infrastructure, which is called Cross-layer Address Resolution (CAR). A smart message interaction for the Binding Update procedure is also introduced. The prototype is illustrated first and a buffering approach adopted to achieve zero packet loss. The proposed scheme, which is called Seamless Handover for Mobile IPv6 (S-MIPv6), evolved from Fast Handover for Mobile IPv6 (F-MIPv6). The problems in F-MIPv6, such as triangle route and sequence disorder, are solved by the proposed scheme. The S-MIPv6 avoids building tunnels and reduces registration delay. It is capable of cooperating with a Mobility Anchor Point (MAP) to take advantage from hierarchical networks. The S-MIPv6 is modeled and simulated. In a practical case, the disruption duration is close to the Data Link layer handover latency (50–100 ms). We believe that the proposed S-MIPv6 is capable of providing seamless handover for time critical services. 相似文献
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In mobile ad hoc networks (MANETs) and wireless sensor networks (WSNs), it is easy to launch various sophisticated attacks such as wormhole, man-in-the-middle and denial of service (DoS), or to impersonate another node. To combat such attacks from outsider nodes, we study packet authentication in wireless networks and propose a hop-by-hop, efficient authentication protocol, called HEAP. HEAP authenticates packets at every hop by using a modified HMAC-based algorithm along with two keys and drops any packets that originate from outsiders. HEAP can be used with multicast, unicast or broadcast applications. We ran several simulations to compare HEAP with existing authentication schemes, such as TESLA, LHAP and Lu and Pooch’s algorithm. We measured metrics such as latency, throughput, packet delivery ratio, CPU and memory utilization and show that HEAP performs very well compared to other schemes while guarding against outsider attacks. 相似文献
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Jen‐Yi Pan Wei‐Jen Lin Ting‐Wei Hsu Kai‐Fang Pan 《Wireless Communications and Mobile Computing》2010,10(3):394-404
IP paging is a well‐known topic, which focuses on reducing amount of binding update (BU). Various IP paging architectures rely on multicast/broadcast to send their messages in wireless network. However, multicast/broadcast is unreliable and has limited bandwidth in power saving mode. This paper uses unicast to avoid exhaustion of the limited bandwidth and reliably page mobile nodes (MNs) by layer 2's supporting acknowledgment in nature. Furthermore, we successfully suppress the amount of BU by remembering and checking MNs' ever attached on‐link care of addresses (LCoAs) in the stack, which is maintained by least recently used (LRU) algorithm for efficiently paging while MNs moving in a localized pattern. We simulate this mechanism to obtain the optimal stack size, which can dramatically reduce the signals of location update and paging. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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Seung‐Hee Hwang Bo‐Kyung Lee Youn‐Hee Han Chong‐Sun Hwang 《Wireless Communications and Mobile Computing》2004,4(2):233-245
The Hierarchical Mobile IPv6 (HMIPv6), which is based on the Mobile IPv6 (MIPv6), has been proposed by IETF to reduce registration control signaling. It separates micro‐mobility from macro‐mobility with the help of an intermediate mobility agent, called the mobility anchor point (MAP), and exploits a Mobile Node's (MN's) spatial locality. However, all packets from a Correspondent Node (CN) to an MN are delivered through the MAP. That causes delay in packets delivery and the congestion of packets in the MAP so that it results in deterioration of network capability. To alleviate these problems, we propose a Hierarchical Mobile IPv6 protocol using not only spatial locality but also temporal locality. We introduce a profile for management of these locality information. According to the information in the profile, some packets are directly delivered to an MN, if MN seems to reside for a long time in the current subnet. Also, we introduce a handover scheme with the help of an L2 trigger, so that the proposed scheme takes nearly the same handover delay time as HMIPv6. The other contribution of this paper is to suggest a mathematical modeling and analysis of network traffic costs, MAP processing costs and handover latency for both HMIPv6 and the proposed scheme. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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Hai Jiang Ping Wang H. Vincent Poor Weihua Zhuang 《Wireless Communications and Mobile Computing》2010,10(4):547-558
Future mobile ad hoc networks are expected to support voice traffic. The requirement for small delay and jitter of voice traffic poses a significant challenge for medium access control (MAC) in such networks. User mobility presents unique difficulties in this context due to the associated dynamic path attenuation. In this paper, a MAC scheme for mobile ad hoc networks supporting voice traffic is proposed. With the aid of a low‐power probe prior to DATA transmissions, resource reservation is achieved in a distributed manner, thus leading to small packet transmission delay and jitter. The proposed scheme can automatically adapt to dynamic path attenuation in a mobile environment. Statistical multiplexing of on/off voice traffic can also be achieved by partial resource reservation for off voice flows. Simulation results demonstrate the effectiveness of the proposed scheme. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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By introducing a mobility anchor point (MAP), Hierarchical Mobile IPv6 (HMIPv6) reduces the signaling overhead and handoff
latency associated with Mobile IPv6. In this paper, we propose a mobility-based load control (MLC) scheme, which mitigates
the burden of the MAP in fully distributed and adaptive manners. The MLC scheme combines two algorithms: a threshold-based
admission control algorithm and a session-to-mobility ratio (SMR)-based replacement algorithm. The threshold-based admission
control algorithm gives higher priority to ongoing mobile nodes (MNs) than new MNs, by blocking new MNs when the number of
MNs being serviced by the MAP is greater than a predetermined threshold. On the other hand, the SMR-based replacement algorithm
achieves efficient MAP load distribution by considering MNs’ traffic and mobility patterns. We analyze the MLC scheme using
the continuous time Markov chain in terms of the new MN blocking probability, ongoing MN dropping probability, and binding
update cost. Also, the MAP processing latency is evaluated based on the M/G/1 queueing model. Analytical and simulation results
demonstrate that the MLC scheme outperforms other schemes and thus it is a viable solution for scalable HMIPv6 networks. 相似文献
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When two opportunistic network peers encounter, utility functions are generally employed to select the messages that have to be exchanged, with the purpose of maximizing message delivery probability and reduce congestion. These functions compute weighted sums of various parameters, like centrality, similarity, and trust. Most of the existing solutions statically compute the weights based on offline observations and apply the same values regardless of a node’s context. However, mobile networks are not necessarily constant in terms of behavior and characteristics, so the classic approach might not be suitable. The network might be split into sub-networks, which behave differently from each other. Thus, in this paper, we show that, by dynamically adjusting the behavior of a node based on its context, through the adjustment of the utility function on the fly, the opportunistic forwarding process can be improved. We show that nodes behave differently from each other and have different views of the network. Through real-life trace-based simulations, we prove that our solution is feasible and is able to improve an opportunistic network’s performance from the standpoint of hit rate, latency, and delivery cost. 相似文献