共查询到20条相似文献,搜索用时 31 毫秒
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位置更新过程由移动终端发起,一般位置更新的失败率在10%以内,造成位置更新失败的原因多为无线链路故障、HLR无用户数据、网络传输故障等,单个LAC区位置更新成功率下降30%基本可以认定为异常。本文通过中创信令监测系统数据,针对上海移动网络发生的位置更新指标恶化进行深入分析,定位了产生位置更新失败的终端型号。 相似文献
2.
How to reduce location updating traffic is a critical issue for tracking the current locations of users in a personal communication
system. Traditional location management approaches usually bring about network overload or bottleneck of the HLR when a mobile
user moves back and forth between adjacent location areas. So far, many works have focused on this research topic to solve
the location updating rate or the location updating cost. In this paper, we shall employ both concepts of time stamp and virtual
overlapping to propose a newly developed scheme for reducing both the location updating rate and the location updating cost.
From the simulated results, our scheme can significantly reduce the location updating traffic. 相似文献
3.
位置管理或移动性管理是移动计算研究领域的一个具有挑战性的问题.我国及其他国家目前正在使用的个人通信网络如GSM、IS-41中,用两层数据库HLR/VLR支持位置管理.在这些网络中,每当移动台从一个位置区LA(Location area)移动到另一个位置区,其基本的位置管理策略(简称"基本策略")不管是否必要均立即进行位置更新操作,因而造成系统资源的极大浪费,降低了系统的性能.本文给出一种带门槛的环形搜索策略(简称"门槛环形策略")——将位置区分成环,设定一个门槛(整数),当移动台越过的位置区的环数没有达到门槛时,系统不进行位置更新操作,以减少位置管理的费用.在假定移动台的呼入是一个泊松过程,移动台在各个位置区的逗留时间是符合一般概率分布的随机变量的条件下,推导出在两次呼入之间移动台处于各位置区环的概率及移动台所越过的位置区环数公式,给出了"门槛环形策略"的位置管理费用小于"基本策略"的条件. 相似文献
4.
GSM网位置更新成功率低的案例分析 总被引:1,自引:0,他引:1
首先对移动网位置更新知识进行了介绍,然后根据A接口的信令消息对失败原因进行了分析,并有针对性地对MSC参数进行了调整,解决了位置更新成功率低的问题。 相似文献
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位置管理是移动通信领域的一个具有挑战性的问题,涉及到位置更新和位置查找操作.我国及其他国家目前正在使用的个人通信网络中,基本的位置管理策略(简称"基本策略")的位置查找操作采用的是,在整个位置区中同步寻呼移动台.由于所要寻找的移动台只在由众多小区所组成的位置区内的一个小区中,因此,"基本策略"会造成系统资源的极大浪费.本文给出一种对位置区内的小区进行分层,按移动台在各层小区的概率从大到小的次序,逐层进行寻呼的位置管理策略(简称"分层策略").在假定移动台在各个小区的逗留时间是符合一般概率分布的随机变量的条件下,推导出移动台处于各层小区的概率及"分层策略"所需搜索的小区平均个数公式.证明了"分层策略"的位置管理费用不大于"基本策略". 相似文献
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Enhanced distance-based location management of mobile communication systems using a cell coordinates approach 总被引:3,自引:0,他引:3
In managing the locations of mobile users in mobile communication systems, the distance-based strategy has been proven to have better performance than other dynamic strategies, but is difficult to implement. A simple approach is introduced to implement the distance-based strategy by using the cell coordinates in calculating the physical distance traveled. This approach has the advantages of being independent of the size, shape, and distribution of cells, as well as catering for the direction of movement in addition to the speed of each mobile terminal. An enhanced distance-based location management strategy is proposed to dynamically adjust the size and shape of location area for each individual mobile terminal according to the current speed and direction of movement. It can reduce the location management signaling traffic of the distance-based strategy by half when mobile terminals have predictable directions of movement. Three types of location updating schemes are discussed, namely, Circular Location Area, Optimal Location Area, and Elliptic Location Area. Paging schemes using searching techniques such as expanding distance search based on the last reported location and based on the predicted location, and expanding direction search are also explored to further reduce paging signal traffic by partitioning location areas into paging areas. 相似文献
10.
A model for estimating car and pedestrian crossing rates at the border of an area is developed. Validation results based on real measurements display the excellent accuracy the model provides. The model is then adjusted to estimate location updating and handover rates in cellular mobile networks.<> 相似文献
11.
The mobility feature of mobile stations (MSs) imposes a large burden on network traffic control as a result of location management. Design issues of location management include MS registration (updating) and call setup (paging). Previous approaches introduced several network topologies for updating and paging procedures, but most of them focused on a single problem: either updating optimization or paging optimization. In this paper, we design and integrate two mechanisms, distributed temporary location caches (TLCs) and distributed home location registers (HLRs), to reduce database access delay and to decrease network signaling traffic in both updating and paging for low power, low tier micro cellular systems. By using TLCs, our approach can improve the performance of updating and paging in comparison with previous approaches. Experimental results based on our analytic model show that our location management procedures have lower HLR access rate, lower registration cost, and lower call setup cost than other approaches. 相似文献
12.
《Communications Magazine, IEEE》1992,30(2):64-69
A mobile cellular network architecture that is based on intelligent network concepts is presented. Subscriber service mobility and call management attributes of the network, including location information retrieval and updating, authentication, call routing, handover, charging, and operations and maintenance, are discussed 相似文献
13.
The partition of location areas is designed to minimize the total costs of finding users' location and tracking their movement in personal communication networks (PCNs). A new scheme to partition and track mobile users and its implementation based on cellular architecture are proposed. According to the tracking strategy, the mobile station (MS) transmits only update messages at specific reporting cells, while the search for a mobile user is done at the vicinity of the cell to which the user has just reported. We use the cost analysis model to demonstrate the feasibility of updating and searching costs to reduce the amount of resources when using wireless channels. Simulations are performed to compare the performance of three schemes: always update, always search, and our new scheme 相似文献
14.
双VLR是移动网用户在位置更新过程中会遇到的较严重的网络故障,对用户呼叫,特别是用户作被叫时有严重影响.本文从问题的发现、问题的捕获过程、分析和解决的全过程进行了详细的介绍. 相似文献
15.
A new packet CDMA network protocol that employs power-controlled transmissions is proposed and analysed. Three types of codes are used, namely base codes as pilot signals, mobile codes for communication purposes, and common codes for registration or location updating. The performance of such a network is analysed for both fading and non-fading channels. 相似文献
16.
Location update optimization in personal communication systems 总被引:1,自引:0,他引:1
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 service area into location registration (LR)
areas. There are various factors affecting this cost, including the mobility and call patterns of the individual MS, the shape,
size and orientation of the LR area, and the method of searching for the MS within the LR area. Based on various mobility
patterns of users and network architecture, the design of the LR area is formulated as a combinatorial optimization problem.
The objective is to minimize the location update cost subject to a constraint on the size of the LR area.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
17.
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
18.
This paper deals with the problem of Location Management in mobile ad hoc networks where users are organized in groups. In the following this type of systems are referred to as Mobile Ad hoc Networks for Group Operations (MANGO). This paper proposes a framework for location management which exploits the trend of mobile users to spontaneously form groups in MANGOs. The management procedures required to support such spontaneous groups, which are by nature dynamic, are introduced as well. The proposed spontaneous group management is based on a hierarchical location database architecture and the concept of Group Leader, which is a terminal responsible for the location update of a group of terminals. Objective of the proposed framework is minimizing the burden on location databases and, at the same time, the signaling issued by terminals. In this paper, distributed operations required to support the whole framework are properly introduced and described. Simulation experiments have been run in order to assess the proposed scheme. Performance results show that the introduced methodology allows reduced signaling and location updating. 相似文献
19.
Eynard C. Lenti M. Lombardo A. Marengo O. Palazzo S. 《Selected Areas in Communications, IEEE Journal on》1995,13(5):893-907
The anticipated emergence of third-generation mobile systems, referred to as universal mobile telecommunication systems (UMTS), raises the problem of reconsidering the design of the databases destined to contain the user information. In particular, it is expected that the key concepts of the new database architectures will be high distribution and fast updating of information. So far, the problem of determining the most appropriate distributed database (DDB) architectures for third-generation mobile systems has not been widely dealt with in literature. This paper presents a methodology for evaluating hierarchical DDB architectures by means of an analytical model of the data querying operation. This methodology allows for structural alternatives, differing on account of the number of levels and branches in the hierarchy, to be evaluated in terms of query loads and mean response times, according to a given user mobility characterization and a given search protocol operation. By way of illustration, the paper discusses a case study, concerning a query operation arising from a location updating procedure and applied to a hierarchical tree-like DDB in which some structural alternatives are considered 相似文献
20.
The cellular network with ad hoc communication has been foreseen in the next-generation mobile communication system. For such a network, a distance-based (DB) location management scheme cooperated with the ad hoc assistance node (DBCAN) is proposed in this paper. Allowing a mobile terminal to pass its mobility information to the ad hoc assistance node (AAN) with appropriate location updating, DBCAN can effectively reduce the paging cost and limit the paging delay. Moreover, DBCAN includes a method to determine whether AANs should be utilized or not to make cost effective. Our simulation results show that DBCAN can effectively reach cost reduction and still get performance improvement even if the probability to successfully deliver mobility information to AANs falls to the median level. 相似文献