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1.
This paper introduces a mobility tracking mechanism that combines a movement-based location update policy with a selective paging scheme. Movement-based location update is selected for its simplicity. It does not require each mobile terminal to store information about the arrangement and the distance relationship of all cells. In fact, each mobile terminal only keeps a counter of the number of cells visited. A location update is performed when this counter exceeds a predefined threshold value. This scheme allows the dynamic selection of the movement threshold on a per-user basis. This is desirable as different users may have very different mobility patterns. Selective paging reduces the cost for locating a mobile terminal in the expense of an increase in the paging delay. We propose a selective paging scheme which significantly decreases the location tracking cost under a small increase in the allowable paging delay. We introduce an analytical model for the proposed location tracking mechanism which captures the mobility and the incoming call arrival patterns of each mobile terminal. Analytical results are provided to demonstrate the cost-effectiveness of the proposed scheme under various parameters 相似文献
2.
In this paper new paging schemes are presented for locating mobile users in wireless networks. Paging costs and delay bounds are considered since paging costs are associated with bandwidth utilization and delay bounds influence call setup time. In general, location tracking schemes require intensive computation to search for a mobile terminal in current PCS networks. To reduce the paging costs, three new paging schemes, reverse, semi-reverse and uniform, are introduced to provide a simple way of partitioning the service areas and decrease the paging costs based on each mobile terminal's location probability distribution. Numerical results demonstrate that our approaches significantly reduce the paging costs for various probability distributions such as uniform, truncated discrete Gaussian, and irregular distributions. 相似文献
3.
Highly mobile users and paging: optimal polling strategies 总被引:2,自引:0,他引:2
We consider the problem of minimizing average paging cost subject to delay constraints in a wireless system. Previous work assumed the unit to be found did not move during the paging process whereas here the unit may change location during polling events. We show that the conditionally most probable locations, given that the unit has not yet been found, should be searched first. We find the optimal sequential paging strategies for given maximum delay constraints and compute both paging and delay costs as a function of the time between polling events. The results show that sequential paging strategies are beneficial in all but the extremely high-mobility cases where polling failures provide little information about the unit location. It is observed that optimal sequential paging strategies substantially lower the paging cost compared to the classical blanket polling at the expense of a small degradation in the average delay performance 相似文献
4.
In today's systems, upon arrival of calls to mobile users, the system attempts to locate the users sequentially (one by one) through a paging operation. In this letter, we propose to concurrently search for a number of mobile users in a mobile network, significantly reducing the cost of locating mobile users. The reduction in the paging costs due to such a concurrent search can be quite substantial, depending on the knowledge of the probabilities of the users' locations, the number of cells in the network, and the number of mobiles to be located. Additionally, we propose a low-complexity heuristic that reduces the average paging cost by 25%, in the case of no knowledge of probabilities of the mobiles' locations. With such knowledge, further reduction in the average paging costs of up to 90% can be achieved. 相似文献
5.
Mobile user location update and paging under delay constraints 总被引:3,自引:0,他引:3
Wireless personal communication networks (PCNs) consist of a fixed wireline network and a large number of mobile terminals. These terminals are free to travel within the PCN coverage area without service interruption. Each terminal periodically reports its location to the network by a process calledlocation update. When a call for a specific terminal arrives, the network will determine the exact location of the destination terminal by a process calledterminal paging. This paper introduces a mobile user location management mechanism that incorporates a distance based location update scheme and a selective paging mechanism that satisfies predefined delay requirements. An analytical model is developed which captures the mobility and call arrival pattern of a terminal. Given the respective costs for location update and terminal paging, the average total location update and terminal paging cost is determined. An iterative algorithm is then used to determine the optimal location update threshold distance that results in the minimum cost. Analytical results are also obtained to demonstrate the relative cost incurred by the proposed mechanism under various delay requirements. 相似文献
6.
Mobility tracking is concerned with finding a mobile subscriber (MS) within the area serviced by the wireless network. The
two basic operations for tracking an MS, location updating and paging, constitute additional load on the wireless network.
The total cost of updating and paging can be minimized by optimally dividing the cellular area into location registration
(LR) areas. In current systems broadcast paging messages are sent within the LR area to alert the MS of an incoming call.
In this paper we propose a selective paging strategy which uses the MS mobility and call patterns to minimize the cost of
locating an MS within an LR area subject to a constraint on the delay in locating the MS.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
7.
In Proxy Mobile IP (PMIPv6) networks, proxy-registrations are performed even for idle MNs, resulting in unnecessary signaling
traffic. Although there have been many IP paging techniques aimed at reducing the unnecessary location update, they focus
only on Mobile IP (MIP) since they had been developed before PMIPv6 was proposed. Thus, adopting existing IP paging support
is not sufficient to support mobility in PMIPv6 networks. For more efficient support, we propose a dynamic multi-step paging
scheme that pages an MN in multiple incremental steps instead of flooding paging messages to a whole paging area to significantly
reduce the signaling traffic caused by the proxy location updates in the PMIPv6 networks. In addition, to improve the paging
delay performance that may be deteriorated by the multi-step paging, the proposed scheme configures paging area dynamically
to raise the efficiency of locating MNs. The size of a paging area is designed to be determined based on the speed of an MN.
We also develop a thorough analytical model for evaluating the performance of the proposed scheme compared with a static paging
scheme in terms of the signaling cost and the paging delay. Thorough analysis and simulation demonstrate that in the PMIPv6
network, our paging scheme can significantly reduce the signaling cost for IP paging, achieving a shorter paging delay, compared
to that of a paging scheme with a fixed paging area. 相似文献
8.
Mobility database that stores the users’ location records is very important to connect calls to mobile users on personal communication
networks. If the mobility database fails, calls to mobile users may not be set up in time. This paper studies failure restoration
of mobility database. We study per-user location record checkpointing schemes that checkpoint a user’s record into a non-volatile
storage from time to time on a per-user basis. When the mobility database fails, the user location records can be restored
from the backup storage. Numeric analysis has been used to choose the optimum checkpointing interval so that the overall cost
is minimized. The cost function that we consider includes the cost of checkpointing a user’s location record and the cost
of paging a user due to an invalid location record. Our results indicate that when user registration intervals are exponentially
distributed, the user record should never be checkpointed if checkpointing costs more than paging. Otherwise, if paging costs
more, the user record should be always checkpointed when a user registers. 相似文献
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11.
Mobility management in heterogeneous wireless networks 总被引:2,自引:0,他引:2
Assouma A.D. Beaubrun R. Pierre S. 《Selected Areas in Communications, IEEE Journal on》2006,24(3):638-648
In heterogeneous wireless networks, mobile users are able to move from their home networks to different foreign networks while maintaining access capability to their subscribed services, which refers to global mobility. One of the key challenges in global mobility management is intersystem location management, which consists of keeping track of mobile users who roam into foreign networks. This paper presents an overview of mobility management in heterogeneous wireless networks and introduces a scheme which improves location management efficiency in terms of total signaling costs and intersystem paging delay. More specifically, cost reduction reaches about 50% when comparing the proposed architecture with conventional architectures. 相似文献
12.
In this paper, we propose to concurrently search for a number of mobile users in a wireless cellular network based on the probabilistic information about the locations of mobile users. The concurrent search approach guarantees that all k mobile users will be located within k time slots. It is shown that even in the worst case when mobile users appear equally in all the cells of the network, the concurrent search approach is able to reduce the average paging cost by 25%. More importantly, this is achieved without an increase in the worst case paging delay or in the worst case paging cost. Depending on the total number of mobile users to be located, total number of cells in the network, and the probabilistic information about the locations of mobile users, the reduction of the average paging cost due to the usage of the concurrent search approach ranges from 25% to 88%. The case in which perfect probabilistic information is unavailable is also studied. 相似文献
13.
This paper considers several optimization problems of sequential paging with aggregation mechanism which has been shown to reduce significantly the paging cost of a wireless communication system. An important problem is to find the optimal aggregation factor subject to a constraint on the average paging delay. Another problem is, given a cost function that depends on both paging cost and paging delay, how to find the optimal aggregation factor to minimize that cost function. We have formulated and shown that these can be solved nicely due to the monotonicity and convexity of the average paging cost function and paging delay function. We demonstrate that the optimization problems of the aggregate factor and subnet clustering are not separable. This leads to joint optimization problems of aggregation factor and clustering that are investigated in this paper. The paper presents different algorithms to solve these joint optimization problems using the monotonicity in the aggregation factor and the number of clusters of the average paging cost and delay with the unconstrained optimal clustering and the structures of the constrained optimal clustering. 相似文献
14.
Lyberopoulos G.L. Markoulidakis J.G. Polymeros D.V. Tsirkas D.F. Sykas E.D. 《Vehicular Technology, IEEE Transactions on》1995,44(3):543-554
Location management procedures, in conjunction with the millions of users expected to subscribe to third generation mobile telecommunication systems, will generate a huge signaling load. In this paper, we propose a method which aims at the reduction of signaling overhead on the radio link produced by the paging procedure. The key idea is the application of a multiple step paging strategy which operates as follows: at the instance of a call terminating to a mobile user who roams within a certain location area, paging is initially performed in a portion of the location area (the paging area) that the so-called “paging related information” indicates. On no paging response, the mobile user is paged in the complementary portion of the location area-this phase can be completed in more than one (paging) step. Various “paging related information” elements (e.g. recent interaction information, high mobility flag, etc.) can be used and several “intelligent” paging strategies can be defined. Representative paging strategies are analyzed in terms of network performance and quality of service (paging signaling, paging delay, processing power requirements), via a simulation tool which models a realistic city area environment 相似文献
15.
The mobility of phones in a cellular or Personal Communication Services (PCS) environment introduces the problem of efficiently locating the called phone. In this paper, we present an analysis of the delay and number of messages transmitted in different sequential and parallel search strategies, considering for the first time the issue of queuing on radio paging channels. Our analysis shows that parallel search may not reduce the time to find a mobile phone if the parameters of the system are unfavorable. We also develop an efficient algorithm for searching with minimum expected number of message when the location of the phone is given by a probability vector. 相似文献
16.
This paper presents a dynamic and individualized location update scheme that considers each user's mobility patterns. The mobility patterns are used to create individualized location areas for each user. The proposed scheme is flexible and can be used in network with arbitrary cell topologies. The scheme, along with other existing schemes is simulated using realistic users' mobility and call arrival patterns, and network topology. The simulated environment consists of 90 cells representing the geographical area of the San Francisco bay, and 66,550 mobile users representing the typical classes of users that are normally present in a real cellular network. Results show the proposed scheme gives lower overall signaling costs, resulting in savings on the limited radio bandwidth that may have otherwise been used for location updates and paging. 相似文献
17.
In Beyond Third Generation (B3G) wireless communications, multiple overlays of wireless access networks may cooperate to allow a user access to novel services, the future demands of which will significantly increase the load on location management systems within the networks. In this paper, we introduce the reader to our novel proposals for providing efficient Mobile Terminal (MT) Location Discovery and Paging across an inter-worked network consisting a Digital Video Broadcast (DVB) network and Universal Mobile Telecommunication System (UMTS) network. We further present numerical and simulation analyzes of our scheme. The numerical and simulation results allow broadcast and cellular network operators to configure their inter-worked system to reduce location management and paging costs whilst controlling average latency. Our results demonstrate that our UMTS LA plus DVB paging schemes offer promise for efficient MT discovery in an inter-network environment that includes uni-directional broadcast network such as DVB; under realistic scenarios we achieve a minimum 4 times reduction in paging cost across the inter-network compared with independent paging systems. Furthermore, we briefly introduce further aspects of research that must be addressed in order to fully evaluate our proposals. 相似文献
18.
在移动IP网络中,层次移动IP协议可降低移动IP位置管理的信令消耗。该文研究支持寻呼的HMIPv6,提出了时延限制下的多步寻呼策略以及基于遗传算法的多步寻呼方案——根据移动节点的位置概率分布,采用遗传算法对寻呼区域内的所有子网进行分组,每步寻呼一个组,使平均寻呼信令开销达到或接近最优。此外,对HMIPv6、单步寻呼的HMIPv6以及基于遗传算法的多步HMIPv6寻呼方案的信令开销进行了比较分析,得出寻呼节省信令开销的必要条件。最后,给出一组数值结果以说明所提出的寻呼策略的有效性。 相似文献
19.
20.
One-dimensional location area design 总被引:1,自引:0,他引:1
Location management cost in a wireless network is expressed in this work as the sum of signaling cost due to paging and signaling cost due to registration. We introduce and compare a heuristic method and an asymptotic method for selecting a disjoint partition of a one-dimensional service area to minimize location management costs. In special cases for which the best design is known, the asymptotic design rule outperforms the heuristic rule, including cases for which the number of location areas is small. With offered load λ, per-event paging cost P, per-event registration cost R, and fixed traffic patterns, optimal location area edges depend on √λP/R and location management costs are proportional to √λPR 相似文献