浅谈七号信令在网络中的应用

No.7信令系统是目前应用最广的信令方式,它不仅应用于电话、数据、移动电话业务,而且适应于综合业务数字网（ISDN）中多种业务的要求。七号信令具有灵活性高、功能强及应用广泛等特点,利用No.7信令可传送并处理国际国内电话网的局间信令、ISDN的局间信令、各种操作管理和维护中心的信息传递业务信令以及用户至用户的端对端信令。七号信令网的畅通与否直接关系到整个电信网的通信质量。因此,对No.7信令进行分析和探讨,己经成为网络优化和日常运维工作中的重要工作。     

国家一级No.7信令网与监控网

信令网是传送Ｎｏ－７公共信道信令的信令消息的电信传输网络,在使用随路信令的年代,没有专用的信令网,或者说信令与话路是在同一话路中传输的,所以电话网就是信令网。随着Ｎｏ－７信令的使用,话路与信令相对独立地由专用链路传送,引出了独立信令网的产生。信令网由于Ｎｏ－７信令系统是一种数字型的信令系统,信令容量极大,其用途不仅是传送电话的所用信令,而且是可支持使用数字信令的一切电信业务网,如ＮＩＳＤＮ,ＢＩＳＤＮ,ＩＮ等,所以Ｎｏ－７信令网是各种业务网的支撑网,是国家的基础设施之一。１Ｎｏ－７信令网结构…     

MAP信令的安全保护研究

移动应用部分(MAP)协议是移动通信网络的信令协议,MAP协议消息是由7号信令网承载,而7号信令网是缺乏安全保护的。为保护在7号信令网上运行的MAP协议,必须利用另外的安全协议。MAP安全(MAPsec)协议为传输MAP消息提供了安全保证。文章研究了MAPsec协议的网络模型、保护模式、消息结构及交互流程,并提出了MAP信令的安全保护方法。     

7号信令及7号信令网技术

７号信令及７号信令网技术＠赵松璞７号信令及７号信令网技术赵松璞公共信道信令系统１．公共信道信令系统的概念对于任何通信系统来讲，系统不仅要传送数据，而且为了使设备之间能够正确发送、接收数据，还应传输一定的控制信号。如图１所示，在简单的从ａ呼叫ｂ，到通话完毕的...     

天津网通七号信令集中监测系统

七号信令网是电信网的重要组成部分,其运行质量直接影响到电信网及各种新业务的稳定运行和经济收益。七号信令集中监测系统通过直接采集七号信令的原始数据进行分析处理,提供对七号信令网实时动态监测,以及各种用户信令的各种微观分析。章在分析七号信令集中监测系统框架的基础上,对监测系统的组网结构、系统功能、软件应用做了进一步的研究。     

七号信令监测系统在山西铁通的应用

七号信令网是电话网、智能网以及各种新业务的支撑网,是通信网络维护建设的重要组成部分。七号信令网主要用于转接交换网的各种控制信令,是通信网的神经,其重要性不言而喻。为了有效的维护七号信令网,就需要建立七号信令监测系统。七号信令监测系统在日常维护的应用直接关系到整个电信网络的性能和通信质量。     

光联网中的信令网

在未来的光网络中，网络的控制管理是关键，完全有必要为光网络提供一种类似于7号信令的信令网，专门用于信令、控制信息、管理信息的传送和处理。本介绍了光信令网的概念，对其产生、实现和目前的趋势都做了介绍。     

七号信令集中监测系统的实现与应用

信令网是现代通信网络的神经中枢,良好的七号信令网能有效的提高呼叫接续质量及接通率等指标,有利于全程全网监控。七号信令集中监测平台是基于整个七号信令网络的实时监测和告警及故障处理系统,本为对七号信令及信令网进行了分析,并对信令集中监测系统的应用提出了自己的观点。     

消息过滤在移动七号信令集中监测系统中的应用

一、引言 随着中国移动通信网络规模的不断扩大以及各种通信业务的迅速增长,作为现代网络通信的神经枢纽,七号信令网在移动通信中发挥的作用也越来越大,对七号信令网管理和维护的要求越来越高。移动七号信令集中监测系统可以准确、完整、有效地获取信令信息,为信令网管理和维护以及业务质量监测和分析提供有效地支撑手段,有极强的应用价值和广阔的市场前景。消息过滤是移动七号信令监测平台中实时应用部分中七号信令规程分析的一个重要组成部分,它的实现对获得完整的信令规程分析,实现网络故障精确定位,有重要意义。同时,也为协议兼容性测试、有效性测试、工程验收提供有力工具。     

深圳市七号信令网的建设

CCITT Na7信令方式具有传输速度快、信号容量大、灵活可靠等优点,已被越来越多的人所共识。目前在我国,七号信令主要用在市话中继上,且仅限于电话业务。深圳也是如此,初期,在部分使用AXE10交换机的局间中继使用了七号信令,九一年对使用NEAX61交换机的9个端局和二个远端交换单元(RSU)全面开通了七号信令系统,采用SP和综合STP的二级信号方式,构成以准对应信号方式为主的七号信令网。本文主要介绍深圳市七号信令网的组成及NEAX61交换机七号信令结构,以供将要开通七号信令的地区参考。     

基于VxWorks的ASON中CCI接口的设计与实现

介绍了ASON体系结构和CCI(连接控制接口)协议机制,同时介绍如何在嵌入式操作系统VxWorks上进行网络通信程序的编写,并结合SDH协议的知识,实现了ASON信令网元与传送网元的接口软件.     

七号信令在现代通信中的应用

七号信令是国际标准化公共信道信令，介绍了七号信令的网络结构和功能结构，及其在公用电话网(PSTN)／综合业务数据网(ISDN)、移动通信网和智能网中的应用。随着现代通信网的快速发展，七号信令有必要引入高速信令链路以解决网络拥塞问题，同时对第三代移动通信系统将影响到现有七号信令的网络结构与协议，七号信令也要与下一代IP网络的融合，以实现电信网与下一代网络体系的互通等问题进行了进一步探讨。     

ATM-based TH-SSMA network for multimedia PCS

Personal communications services (PCS) promise to provide a variety of information exchanges among users with any type of mobility, at any time, in any place, through any available device. To achieve this ambitious goal, two of the major challenges in the system design are: (i) to provide a high-speed wireless subsystem with large capacity and acceptable quality-of-service (QoS) and (ii) to design a network architecture capable of supporting multimedia traffic and various kinds of user mobility. A time-hopping spread-spectrum wireless communication system called ultra-wide bandwidth (UWB) radio is used to provide communications that are low power, high data rate, fade resistant, and relatively shadow free in a dense multipath environment. Receiver-signal processing of UWB radio is described, and performance of such communications systems, in terms of multiple-access capability, is estimated under ideal multiple-access channel conditions. A UWB-signal propagation experiment is performed using the bandwidth in excess of 1 GHz in a typical modern office building in order to characterize the UWB-signal propagation channel. The experimental results demonstrate the feasibility of the UWB radio and its robustness in a dense multipath environment. A ATM network is used as the backbone network due to its high bandwidth, fast switching capability, flexibility, and well-developed infrastructure. To minimize the impact caused by user mobility on the system performance, a hierarchical network-control architecture is postulated. A wireless virtual circuit (WVC) concept is proposed to improve the transmission efficiency and simplify the network control in the wireless subsystem. The key advantage of this network architecture and WVC concept is that the handoff can be done locally most of the time, due to the localized behavior of PCS users     

Digital Time Division Switching for Military Communications

This paper describes system designs and design techniques applied in the design of a digital time-division switching system for a military communication network. The digital switches are interconnected by bit interleaved digital time-division multiplexed trunk groups. The switching system uses an advanced non-blocking, bit interleaved, digital time-division switch matrix to switch synchronous voice and data communications. The nodes of the model network are timed by high accuracy atomic clocks and use first-in-first-out buffers to compensate for clock frequency differences. The digital switching system uses common channel digital message signaling to communicate signaling and supervision data between connected switching centers. Signaling channels use a comprehensive error control system to provide reliable signaling and maintain signaling throughput in adverse transmission noise environments. The switching system's stored program control provides a telephone switching system which can be applied to many different networks. The flexible stored program control enables the same hardware system to perform switching for networks with different network signaling and/or routing/numbering plans.     

H.323-SIP信令网关的实现

H.323和会话初始化协议（SIP）都是基于IP网络的多媒体通信协议,采用实时传送协议（RTP）传送实时的音频视频传输,二者之间可以通过设置信令网关互通,完成信令消息的翻译和转换功能。要实现H.323与SIP网络之间的互通,必须解决地址格式的转换、消息映射和终端能力协商等方面的问题。H.323-SIP信令网关在H.323和SIP互通中占有得要的地位,它能够使位于不同网络的用户直接和对端进行媒体交换,实现点到点、点到多点之间的通信。H.323-SIP信令网关的功能会越来越完善,也会越来越适应用户更加广泛的业务需要。     

Implementation of SS7: Italtel's experience

Field results in implementing Signaling system No.7 (SS7) in preparation for the introduction of intelligent network (IN) services are reported. Besides implementing SS7 for interexchange trunk signaling, Italtel has adapted it for communications with remote units, i.e. remote switching modules and subscriber multiplexers and concentrators. IN implementation in a distributed system is discussed. The distributed architecture of the Linea UT intelligent network is described     

Multimedia communications for users

Research on next-generation multimedia communications services and technologies within a highly interdisciplinary research program that encompasses behavioral science, computer science, and electrical engineering is discussed. The authors state that they have taken an approach to their research that allows the needs of users and the demands of end-to-end applications to shape the future of the multimedia communications network. They use several examples to show how such a perspective affects the development of practical, advanced communications services. These examples span a wide range, including: empirical studies of people's use of technology to communicate in collaborative work settings; the design of software supporting the real-time network delivery of interactive multimedia documents for casual information users in the home; and the creation of next-generation prototypes that support the transmission and viewing of multimedia information in homes, offices and classrooms     

Performance of ultrawideband SSMA using time hopping and M-ary PPM

Wireless spread spectrum multiple access (SSMA) using time hopping and block waveform encoded (M-ary) pulse position modulated (PPM) signals is analyzed. For different M-ary PPM signal designs, the multiple-access performance in free-space propagation renditions is analyzed in terms of the number of users supported by the system for a given bit error rate, signal-to-noise ratio, bit transmission rate, and number of signals in the M-ary set. The processing gain and number of simultaneous users are described in terms of system parameters. Tradeoffs between performance and receiver complexity are discussed. Upper bounds on both the maximum number of users and the total combined bit transmission rate are investigated. This analysis is applied to ultrawideband impulse radio modulation. In this modulation, the communications waveforms are practically realized using subnanosecond impulse technology. A numerical example is given that shows that impulse radio modulation is theoretically able to provide multiple-access communications with a combined transmission capacity of hundreds of megabits per second at bit error rates in the range 10^-4 to 10^-7 using receivers of moderate complexity     

Resource management model and performance evaluation for satellite communications

Efficient resource management is mandatory to achieve maximum system capacity for next generation communications systems. Resource management deals with the available spectral band, time, power, and space for a transmission signal. It includes (i) the frequency planning, (ii) the selection of transmit power, and (iii) the assignment of the channels and access nodes to the users. The paper presents a generalized notation as well as graph algorithms for resource management problems. Impairment graphs can be used for frequency planning, whereas flow graphs are suitable for channel access problems. To evaluate the performance of the resource management, service criteria (such as blocking or the carrier to interference ratio C/I) or efficiency criteria (bandwidth requirements) can be derived from the graphs. The resource management techniques are applied to satellite networks with non‐geostationary orbits yielding time‐variant network topologies. As a simple example, the channel assignment and capacity optimization of the EuroSky Way system are shown. Furthermore, a comparison of fixed, dynamic and hybrid channel allocation schemes (FCA, DCA, HCA) for a typical MEO satellite scenario is given. Satellite diversity and its impact on bandwidth requirement and transmission quality is also examined. Finally, it is shown how spread spectrum systems can be investigated with the presented tools. Copyright © 2001 John Wiley & Sons, Ltd.     

A performance evaluation approach for GSM-based information services

The ever increasing diffusion of mobile communications will lead to massive mobile access to the Internet. The paper focuses on the wireless application protocol (WAP) for providing mobile information services, as envisaged by the personalized access to local information and services for tourists (PALIO) project within the fifth research framework of the European Commission. In particular, we consider a global system for mobile communications (GSM) network where WAP traffic is transported by the short message service (SMS) on specific GSM signaling channels. We develop suitable traffic models for both the WAP downlink traffic and the signaling traffic. An analytical approach is described that allows evaluation of the mean transmission delay of a WAP page. Finally, a downlink traffic scheduling policy is proposed in order to reduce the delay variance so that users experience a more regular traffic behavior (service usability requirement). The theoretical derivations for the GSM-SMS scenario are general and can also be tailored for other mobile communication systems. The study allows dimensioning of both the service and the downlink signaling traffic capacity in order to fulfill quality-of-service requirements for users.