寻呼区域覆盖同播的卫星链路技术

区域覆盖同播是无线寻呼联网发展的主要趋势之一，本文简述寻呼系统中区域覆盖同播的构成及功能，介绍了寻呼区域覆盖同播的卫星通信链路控制技术，并与传统的通信连接方法作了比较。     

卫星寻呼广域联网系统组网方案

卫星寻呼广域联网系统是专门为跨省、跨地区经营的大寻呼台实现区域覆盖及广域联网而设计的ＶＳＡＴ应用系统，该系统采用单向广播主站实现寻呼的同播覆盖，采用以向小站实现区域间联网信息的交流，圆满解决了广域寻呼系统的漫游联网，同播覆盖、多频复用、同频干扰等问题，为卫星数据广播在寻呼领域内的应用开辟了广阔的前景。     

卫星控制无线寻呼系统

利用卫星高覆盖的特点，对寻呼系统的联网具有很多优点，本文介绍了ＶＳＴ卫星通信网的结构及特点，卫星寻呼信号的传送过程和双向ＴＮＰＰ广域覆盖系统。     

卫星控制无线寻呼系统

利用卫星高覆盖的特点，对寻呼系统的联网具有很多优点，本文介绍了ＶＳＡＴ卫星通信网的结构及特点，卫星寻呼信号的传送过程和双向ＴＮＰＰ广域覆盖系统。     

采用多基站同播方式的无线寻呼系统

本文介绍了两种采用多基站同播方式的无线寻呼系统；单寻呼终的简单系统和多寻呼终端的区域覆盖系统，并对多基站同播系统中的时延匀衡技术进行了介绍，最后给出摩托罗拉公司ＰＵＲＣ５０００型同步寻呼发射机实例。     

技术进步是寻呼业发展的真正源动力

寻呼业的发展与变化 １．竞争格局的变化 寻呼业开始时是邮电部门一统天下，１９９３年开放寻呼市场业务后，出现了百花争鸣群雄逐鹿的竞争性格局。发展到现在，出现了４种类型的寻呼台，既有国信寻呼、联通寻呼这样的国家队，又有全国联网台、省网台以及独立的寻呼台。 ２．寻呼覆盖方式的变化 从早期以独立城市为中心进行覆盖的各自为政的地方台，到有一定规模的省内区域联网同播覆盖，再到覆盖全省范围的省同台，现在已形成以天网、地网的同播覆盖和联网漫游登记方式覆盖全国的全国联网台。以笔者的观点，在今后的发展中，省网台和全国联网台将会占据越来越多的市场份额，并最终逼迫一部分未实现联网的地方台，要么参加到联网台中，要么逐步退出寻呼市场。 ３．寻呼服务内容的变化 经历了从单纯人工寻呼服务到人工／自动兼容服务，从简单电话信息传递到综合信息服务，甚至具备了向特定大客户提供具备一定特殊功能的客户服务（呼叫处理中心）的潜在能力。 ４．排队技术上的变化 早期是简单的无交换设备的电话模拟中继接入，后来是众多品牌进口交换机的程控交换，随后出现了国产排队机和ＰＣＭ数字中继接入。 ５．寻呼编码技术上的变化 经历了早期５１２ｂｉｔ／ｓ ＰＯＣＳＡＧ码编码、５１...     

GL3000自动寻呼系统呼叫流程的修改

ＧＬ３０００自动寻呼系统呼叫流程的修改姚卫刚山东省公用寻呼网于１９９５年５月１日完成全省联网。全省１７个地市局全部采用了加拿大建利尔公司的ＧＬ３０００自动寻呼系统，市区内采用同播形式，市区间采用ＤＤＮ线路连接。从运行一年的情况来看，设备本身十分稳定，...     

多基站同播通信系统设计

本文讨论一种分区覆盖的广域通信系统-多基站同播通信系统,介绍了同播系统的特点,阐述了同播系统信号失真的机理和消除信号失真的方法。对基站发射频率的一致性、调制信号的幅频特性、相频特性的差异以及CTCSS信号对同播系统的影响进行了分析,并对这些影响因数给出了具体的要求及实现方法,本文还详细介绍了同播系统优化调节的方法及步骤。     

卫星寻呼的新技术

采用调相单路单载波信号，可连接多部寻呼发射机进行同播。通过帧中继分组通信，可改进双向链路骨干网。     

四路无线寻呼卫星通信系统

<正> 四路无线寻呼卫星通信系统是利用现有的“中卫”五号卫星上转发的各省(路)电视节目中的空间伴音信道,应用独立边带-移频(ISB-FM)双重调制多工通信技术,实现在卫星覆盖范围内全国组网的无线寻呼通信系统。该无线寻呼网络原则上不用有线中继线路,不用增加中继通信频率,只要在“中卫”五号卫星覆盖区内的任何地点都可以联网,这不仅可以实现全国县以上城市联网,还可以实现旅游点或边远城市、港澳以及国外城市联网,具有网点多、易联网、成本低、质量好等特点。第一个四路无线寻呼卫星通信系统已于1995年10月在济南开通。实践证明这是一个技术先进、性能稳定、实用性强、经济效益好的无线寻呼系统。     

移动IP网络中基于遗传算法的多步寻呼策略及性能分析

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。     

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     

Dynamic multi-step paging scheme in PMIPv6-based wireless networks

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.     

A parallel shuffled paging strategy under delay bounds in wireless systems

In sequential paging schemes, the paging process is considered on per user basis. When an incoming call arrives to a mobile terminal (MT), the associated location area is divided into several paging areas (PAs) and PAs are paged one by one until the MT is found. Even though sequential paging algorithms can reduce the paging cost compared to the blanket-paging scheme, they introduce extra and unnecessary delay due to the fact that, during each paging cycle, unpaged cells are idle and unused in terms of paging. In this letter, a simple parallel shuffled paging strategy is proposed to reduce delay and improve performance. In the proposed scheme, multiple MTs can be paged in difference PAs in parallel. Our study shows that the proposed scheme outperforms both the sequential paging and the blanket paging in terms of discovery rate and queueing delay.     

A simple analytical framework for location management in personalcommunication systems

Efficient mobility management for portable stations (PS's)-handoff, channel assignment and locating-will play an important role in future personal communication systems (PCS's). Among these tasks, location management plays a critical role for wide-area roaming. The key elements of locating are location registration/updating and paging. Due to the smaller cell size in PCS, the high boundary crossing rate of PS will result in more frequent location area (LA) updating. This, in turn, will result in more interrogations with location registers, which will generate a higher volume of access and signaling traffic (SS7 traffic). One solution to this problem is to increase the size of LA, which, unfortunately, also increases paging traffic. Efficient paging algorithms may generate relatively less paging traffic such that larger LA's may become plausible. Depending on the call-arrival rate to the cell, boundary crossing rate, optimum size of LA, and paging technique used, the overall cost could vary substantially. The paging techniques considered in this paper are simultaneous paging and sequential paging. The two schemes are studied in detail in order to understand the problems associated with location management in the PCS environment. In the authors' opinion, this paper provides, for the first time, a simple yet powerful analytical framework which can be used to analyze “intelligent” paging schemes as well as simultaneous and sequential paging     

SIP Paging and Tracking of Wireless LAN Hosts for VoIP

This paper introduces a new paging technique to track and wake up a mobile node (MN) attached to an access point (AP) in a wireless LAN network after a session initiation protocol (SIP) INVITE message is initiated by a caller. A tracking agent (TA) keeps track of the mobiles' handoffs between the APs. A paging agent (PA) triggers the TA to page the mobile when a SIP INVITE is received for one of its users. The context transfer feature of our paging protocol allows the paging messages to deliver the station context in order to enable faster session reestablishment. The AP then does onlink paging in a wireless link. SIP extensions are needed to trigger the PA to start paging MNs to notify their dormant status using an extended SIP REGISTER method. Tracking protocol is analyzed to compare soft- and hard-state approaches for state inconsistency ratio, message rate, and the overall cost. The simulation model we developed enables us to evaluate the traffic introduced by the tracking protocol and the cache (state) size. Paging protocol is analyzed for CPU processing times and the transmission delays in the SIP session setup with paging. Simulation of the paging with context transfer is used to show the gains in reauthentication.     

A dynamic paging scheme for long‐term evolution mobility management

In long‐term evolution, the service area is partitioned into several tracking areas (TAs), which comprise one or more cells (the radio coverages of base stations). The TAs are grouped into TA list (TAL). When an incoming call arrives, the network attempts to connect to the user equipment (UE) by paging the cells in the UE's TAL, which may incur large paging traffic that significantly consumes the limited radio resources. To resolve this issue, this paper proposes a dynamic paging scheme that determines the paging sequence of cells in real time according to the UE movement and call behavior. We compare the performance of the dynamic paging with that of the previously proposed Cell‐TA‐TAL (CTT) paging. Our study indicates that the dynamic paging outperforms the CTT paging when movement pattern is regular and the UE moves frequently. Copyright © 2013 John Wiley & Sons, Ltd.     

A comparison of different paging mechanisms for mobile IP

This paper proposes two Individual paging schemes, then presents a comparative analysis on the signaling cost functions of Mobile IP (MIP) with different paging protocols and paging schemes and investigates constructing optimal paging areas using discrete system model as a mobility model. In wireless mobile Internet, mobile hosts often visit foreign networks that might be far away from their home networks and the occurrences of their inter-domain movement are relatively rare. In this scenario, our analytical results show that paging, particularly individual paging, can significantly improve the total signaling cost of MIP. We show that Domain paging can bring about considerable cost saving compared to FA (Foreign Agent) paging. Our results also demonstrate the significant advantages of Individual Paging over Static Aggregate Paging. The results show that specifying the optimal paging area size is critical in saving signaling cost of MIP with paging support. Hung Tuan Do received the B.E. degree in Electrical Engineeing and Computer Science from Hanoi University of Technology, Vietnam, and the M.E. and the Ph.D. both from Gunma University, Japan. His research interests include Mobility Management, Wireless Internet and Mobile Ad hoc Networks. Yoshikuni Onozato is a Professor with Gunma University. His research interests are in satellite systems, computer communication networks and distributed computing systems and span the entire spectrum from the design and performance evaluation of these systems to their implementation. He is a member of IEEE, ACM, IPSJ, ORSJ and IEICE.     

WAP网关实现研究

无线应用协议（Ｗｉｒｅｌｅｓｓ Ａｐｐｌｉｃａｔｉｏｎ Ｐｒｏｔｏｃｏｌ,ＷＡＰ０产品的开发与部署将基于因特网的网络应用技术与无线数据网络通信技术进行有效地结合,是当前产业界和研究界所共同关心的热点问题。文中就ＷＡＰ应用的核心技术之一－ＷＡＰ网关的实现与性能测试问题进行研究,讨论了我们所研发的一种基于ＵＮＩＸ平台和多线程技术的ＷＡＰ网关实现方法,分析了具体实现中的关键技术,并就ＷＡＰ网关实现的性能改进与测试工作进行分析和讨论,大量测试的结果表明,采用上述技术所研发的ＷＡＰ网关具有高的可靠性和运行性能。     

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.