一种应用位置预测的动态寻呼框架

移动通信系统里评估系统的一项重要指标是用户在移动过程产生的信令消耗。在现行4G网络中,当核心网向目标终端发送寻呼时,在跟踪区域列表里的所有小区都要发送寻呼信令,造成了不必要的信令浪费。为减少寻呼信令的消耗,提出了一种移动性管理的框架,此框架可以分为预测部分和回落部分,其中预测部分提供了移动性管理与预测算法有机结合的方案,回落部分则使用马尔科夫链对寻呼过程进行分析,在预测失败时采取动态寻呼的方式。对该框架进行建模和仿真可以看出,所用的寻呼方案能有效减少移动终端的非接入层处于空闲态时进行移动性管理中寻呼信令的开销。     

GSM网小区寻呼丢弃优化方法

小区寻呼丢弃数量不仅是衡量网络性能的重要指标之一,同时与用户感受密切相关。GSM网寻呼丢弃量与网络寻呼策略、LA（位置区）寻呼容量、寻呼组设置、业务分担参数设置等因素息息相关。主要针对造成寻呼丢弃的多种原因分析,并结合实际优化案例说明通过LA分裂、对MFRMS（寻呼信道复帧数）参数及T3314参数调整均能够有效改善小区寻呼拥塞从而降低寻呼丢弃数量,对全网寻呼成功率的提高也有一定效果。     

LTE系统中小区搜索研究

在移动通信系统中,小区初始搜索是LTE-TDD系统一个非常关键的过程,处于物理层过程的第一步。通过该过程,用户终端（UE）可以搜索到一个可用的小区,并获得符号同步和帧同步。只有在完成小区初搜以后,UE才能后获取本小区更详细的信息以及邻近小区的信息,才可以监听寻呼或发起寻呼。     

联合处理中自适应调度算法研究

在新一代移动通信中,协作多点传输技术因其可以有效提高边缘用户性能而被广泛研究.对于协作多点传输来说,其核心思想是通过不同小区间协作来改变边缘用户的性能,从而提升系统性能.针对单用户多输入多输出的特点,本文是在经典调度算法的基础上改进了的自适应调度算法,此算法在每个时频资源块上灵活的选择较优的传输模式,从而增强系统性能.通过仿真表明了这种调度算法在保持较好公平性的同时,又可以很好的提升平均小区吞吐量和边缘用户频谱效率.     

一种提高小区边缘用户性能的多用户子载波功率分配策略

在OFDMA系统中,小区边缘用户由于受到来自相邻小区的同频干扰,通信质量严重下降.有效地抑制小区间干扰,极大地提升无线网络性能尤其是小区边缘用户性能是5G移动通信系统的目标之一.基于速率自适应(RA)准则提出了一种提高小区边缘用户性能的子载波和功率的联合资源分配算法,该算法分为子载波分配和混合功率分配两步,在提高小区边缘用户性能的同时,最大化链路吞吐量.仿真结果表明,小区边缘用户吞吐量增益为25％以上,混合功率分配下的系统吞吐量逼近全部用户使用注水法时的系统吞吐量,并且降低了运算复杂度.     

泛欧无线消息系统

近年来无线寻呼正向着国际漫游的方向发展,尤其是欧洲国家,开发了一种新型国际无线消息系统,即泛欧无线消息系统（ERMES）,它为国内用户和那些离开归属国家在外漫游的用户提供寻呼业务。ERMES是第一个规定了传输频率的寻呼标准技术规范,其信道容量极高,工作频率可达6250Mbit／s,在很大程度上支持了日益增长的用户数量,ER－MES每个信道可支持大约50万个用户,是现有系统的5～10倍。ERMES对基本业务进行了改善,如数字寻呼可达20个字符,最大消息长度为16000个数字字符;字母数字寻呼至少可达400个字符,最大消息长度为9000…     

移动通信的几种新型天线

移动通信的几种新型天线章燕翼（人民邮电出版社北京１０００６１）·名词与术语·智能天线系统（ｓｍａｒｔａｎｔｅｎｎａｓｙｓｔｅｍ）目前移动通信基站的天线大部分是全向性的天线，在寻呼移动通信用户时是在覆盖的整个小区寻找，天线的功率和信号强度大部分消耗在传...     

关于TMSI寻呼与IMSI寻呼性能分析

随着移动用户的持续增长和手机新业务的不断推广,移动通信系统的寻呼负荷日益加重。以移动用户漫游被叫时的呼叫流程为例,分析IMSI寻呼和TMSI寻呼的原理,对比两种寻呼方式对网络性能影响,提出一种评估寻呼方式的量化计算方法。通过对寻呼容量较为紧张网元的试验证明,该方法可以科学指导寻呼方式的优化工作,提高移动通信网络的系统寻呼容量,改善移动通信系统寻呼性能。     

国际寻呼系统简介

国际寻呼系统简介＠曾晓延国际寻呼系统简介曾晓延无线电寻呼是一种普及型的大众化的移动通信方式。目前寻呼所能提供的服务品种已有音响寻呼、数字寻呼、文字寻呼、语音寻呼、双向寻呼、带寻呼提示的语音信箱、传真信箱、电子信箱、用户终端入网、Ｉｎｔｅｒｎｅｔ上网寻呼等众...     

HRPD系统中基站协作式迭代并行小区间干扰消除技术

高速分组数据(HRPD)技术能够很好地支持移动通信网络中各种类型数据分组应用,采用干扰消除技术能够有效提高系统的容量和对各用户信号正确接收.基于基站协调器的协作式迭代并行小区间干扰消除算法利用基站协调器监视相邻小区的强干扰用户,并且通过信令传递强干扰用户的特征信息,利用基站协调器的协作采实现迭代式的并行小区间干扰消除.仿真结果表明,该算法可以有效的消除邻近小区对本小区的干扰,与不使用小区间千扰消除技术相比较,其性能有所提高.     

Optimal Sequential Paging in Cellular Wireless Networks

In a high-capacity cellular network with limited spectral resources, it is desirable to minimize the radio bandwidth costs associated with paging when locating mobile users. Sequential paging, in which cells in the coverage area are partitioned into groups and paged in a non-increasing order of user location probabilities, permits a reduction in the average radio costs of paging at the expense of greater delay in locating the users. We present a polynomial time algorithm for minimizing paging cost under the average delay constraint, a problem that has previously been considered intractable. We show the conditions under which cluster paging, a simple heuristic technique proposed for use with dynamic location update schemes, is optimal. We also present analytical results on the average delay and paging cost obtained with sequential paging, including tight bounds.     

Effective Paging Schemes with Delay Bounds as QoS Constraints in Wireless Systems

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.     

Concurrent search of mobile users in cellular networks

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.     

Non-Blocking Pipeline Paging with Known Location Probabilities for Wireless Systems

Paging schemes for wireless systems have been well studied in the literature. However, most schemes are considered on per user basis. In these schemes, when an incoming call arrives at a mobile terminal (MT), a paging request (PR) is put in a queue. PRs are served in an FIFO manner. When a PR is served, a search process is carried out to find the corresponding MT in a location area (LA). Most schemes study how to achieve a better performance in terms of cost with/without delay constraints per PR, and totally ignore other PRs in the queue until the MT is found or all the cells in the LA have been paged. In this paper, we propose a non-blocking pipeline probability paging scheme, which assumes known knowledge on location probabilities of individual MTs, under a paging delay constraint, where the location probability of an MT in a cell is the probability that the MT is in the cell. The proposed scheme is independent of the number of PRs in the queue and the arrival rate of PRs. Our study shows that the proposed scheme outperforms both the sequential probability paging scheme with known knowledge on location probabilities of individual MTs and the blanket paging scheme in terms of discovery rate and the total delay. Finally, we study several optimization problems with quality of service constraint for the pipeline probability paging scheme.     

Movement-based location update and selective paging for PCSnetworks

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     

Concurrently searching for mobile users in cellular networks

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.     

TD-LTE系统TA及TAlist规划原则

本文首先介绍了TD-LTE系统位置区的管理机制,其次从TD-LTE系统能力以及目前TD-LTE设备性能等角度,分析了TD-LTE网络的寻呼机制和寻呼容量,最后通过预测LTE小区的用户数目以及单用户寻呼模型,给出了TA/TA list的规划原则和建议。     

Intelligent paging strategies for third generation mobiletelecommunication systems

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     

User Independent Paging Scheme for Mobile IP

Multi-step paging has been widely proposed in personal communications services (PCS) systems to reduce the signaling overheads. Similar ideas can be applied to Mobile IP to provide IP paging services. However, current proposed multi-step paging schemes are user dependent under which the partition of paging areas and the selection of paging sequence are different for each user. The performance of a user dependent paging scheme for individual users may be affected by many factors. It is often difficult to achieve perfect performance for each user. In addition, when multiple users are paged at the same time, user dependent paging schemes may consume significant system resources. This paper introduces a user independent paging scheme where the paging criterion is not based on individual user information. The goal of user independent paging is to provide satisfactory overall performance of the whole system, when personalized optimal performance for each user is hard to obtain. The user independent paging scheme is proposed for IP mobility for its easy implementation and convenient combination with paging request aggregation. The paging criterion adopted is the mobility rate of each subnet determined by the aggregated movements of all mobile users. In order to implement the proposed scheme, a concept of “semi-idle state” is introduced and the detailed solution for obtaining mobility rate is presented. Analytical results show that when paging one user at a time, the performance of the proposed user independent paging scheme is comparable to that of the paging schemes based on perfect knowledge of user movement statistics. When paging multiple users simultaneously and when the knowledge on individual user behavior is not perfectly accurate, the proposed scheme has remarkable advantages in terms of reducing the overall paging cost. Jiang Xie received her B.E. degree from Tsinghua University, Beijing, China, in 1997, M.Phil. degree from Hong Kong University of Science and Technology in 1999, and M.S. and Ph.D. degrees from Georgia Institute of Technology in 2002 and 2004, respectively, all in electrical engineering. She is currently an assistant professor with the Department of Electrical and Computer Engineering at the University of North Carolina-Charlotte. Her current research interests include resource and mobility management of wireless networks,QoS provisioning, and next-generation Internet. She is a member of IEEE and ACM.     

A contention-free mobility management scheme based on probabilisticpaging

In forthcoming personal communication systems (PCSs), small cells are deployed to achieve high spectral efficiency. This has significant impacts on location tracking of mobile users. The increase in location update (LU) load leads to more contention on the reverse control channel. Thus, many algorithms are designed to distribute the LU load to a larger number of cells. This avoids the inefficiency of random accessing due to high offered load. In an alternative approach (Wong 1995), a contention-free LU algorithm is proposed. Two or more mobile units are permitted to register with a base station simultaneously without contention. A probabilistic paging mechanism called Bloom filtering is used to select cells to be paged. Since there is no contention in LU, inefficiencies due to random accessing are bypassed. In this paper, we present another contention-free LU algorithm. It is hybrid in the sense that LUs are temporally or geographically triggered. The use of hybrid LU alleviates inefficiencies inherent to temporal triggered LU in Wong. Three selective paging schemes are considered in this paper. Tradeoff between paging delay and paging bandwidth is addressed. The performance of this algorithm is compared to Wong and other conventional strategies. Numerical results show that the new algorithm compares favorably with previous proposed strategies