构筑在GPRS之上的VAP应用

WAP规范了一种建立在各种承载之上的应用平台,为移动用户提供了统一,开放的应用接口。在各种承载网络的应用中,构筑在GPRS（通和分组无线业务0之上的WAP是目前最佳的方案。本文从协议和网络结构两个方面对构筑在GPRS之上的WAP进行分析,并就移动终端的接入过程作了讨论。     

WAP over GPRS技术及应用前景

文章详细介绍了目前手机上网的两大关键技术WAP和GPRS技术，给出了WAP的通信模型和WAP的分层协议结构，以及GPRS的网络结构、协议和GPRS较以前网络的技术优势。最后阐述了WAP over GPRS的应用前景。     

多媒体消息服务

MMS是3GPP规范中定义的移动数据业务,它利用WAP协议作承　载,短消息作通知,用户可以像使用短消息一样收发更加个性化的多媒　体消息,如:文本、图形、图像、音频、视频、动画、音乐等信息内容。　 多媒体消息服务要求一个WAP/PUSH代理网关、适用于大量信息传　输的配置、一个数据传输网如电路交换网、GPRS或UMTS网络,和一个　短消息中心。MMS业务以WAP作承载,短消息作提示通知,纯属应用层　业务。多媒体信息中心（MMS-C）并不直连核心移动网络,而是通过HTTP PAP（PushAccessProtocol）连接WAP网关,SMPP连接SMS-C。 　 多媒体消息服务并不依赖于哪一代网络,它能够在第2代、第2.5代　及第3代无线网络中实施。无论CSD、HCSD,还是EDGE、GPRS、UMTS,　都可以支持MMS业务。鉴于网络带宽、传输速度和移动终端方面考虑,　MMS业务将在当前GPRS网络上起飞,在未来3G网络中走向成熟。 　当前MMS手机支持以下几种业务方式:手机端到端双向收发　MMS;手机到E-mail双向收发MMS;Web向手机下发MMS。     

GPRS手机

诺基亚 查询号194诺基亚8310通过基于GPRS的WAP功能可以快速、及时地接入基于网络的信息和服务,并实现“永远在线”。在GPRS网络中运行WAP的情况下,只要打开GPRS手机,就能通过GPRS网络与移动服务建立快速连接。GPRS以分组方式传送数据,从而使根据信息收发的数量,而不是根据连接时间的长短来收费的模式成为可能。基于GPRS技术的WAP应用使用户可以上网浏览餐馆指南,或查询当地影院节目单。此产品还支持HSCSD,实现灵活的数据连接。GPRS手机     

在GPRS之上构筑WAP网络的方案研究

从协议和网络结构两个方面对构筑在GPRS之上的WAP进行了分析,并就分组数据接入过程进行了讨论。     

移动通信小常识

1WAP WAP（Wireless Application Protocol）是无线应用协议的缩写,相当于无线上网的TCP/IP。具有WAP功能的终端设备,如WAP手机,通过手机内置的微型浏览器,经由数字无线网络,如GSM网络登陆互联网。 WAP内容用WML编写,在手机上显示的内容以文字为主。WAP的最大优点是移动性,用手机你可以在任何时候、任何地点上网,带来无与伦比的便捷和自由。 另外,通过网络可以知道用户的所在位置,也就可能把与位置相关的信息提供给用户,如交通、附近的医院、饭店、酒吧、电影院、提款机等信息。 WAP与GPRS属于不同的范畴,它的目的是将互联网的丰富信息及先进的业务引入到移动电话等无线终端之中来。打个比喻,GPRS和GSM都是马路,而WAP是在马路上高速行驶的汽车。 当移动开通GPRS之后,WAP就行驶在GSM和GPRS两条马路上,而行驶在GPRS马路上可以提高数据传输速度。因此,现有WAP上的内容一样可以通过GPRS进行浏览和应用。     

开放源码的WAP网关

1997年6月,Motorola、Ericsson、Nokia、UnwiredPlanet（现为Phone．com公司）4家无线设备生产厂商共同组成了无线应用协议（WAP）论坛,旨在洛因特网的海量信息和业务引入到无线通信终端上,产生一个适用于不同无线网络技术的全球无线协议规范,并使其成为行业标准。到2000年6月,加入WAP论坛的厂商已有241家。1999年12月,WAP论坛正式公布WAP1．2标准。WAP的编程模型如图1所示,其中,WAP代理由协议网关和内容编码解码两部分功能组成,协议网关用来完成从WAP协议（WSP、WTP、WTLS和WDP）的请求到WWW协议（HTTP、TCP…     

WTP协议在OPNET中的实现

WAP是基于Internet技术标准以及一些无线通信公司制定的无线服务标准之上的一个规范。WTP是协议栈 中的核心部分。本文阐述了如何利用WAP协议规定的特性和参数在OPNET8.1上建立WAP协议模型,着重阐述了WTP的实 现,并说明利用此模型可以方便的仿真负载对基于各种底层承载的移动网络的影响。     

无线上网由移动通信业主导

在无线上网的历史中，众所周知的是WAP的失败，以及日本在无线上网市场的成功。分析两者各自的原因，就能发现其背后有着复杂的产业因素。然而追根究底，无线上网市场要成功的关键却只有两个：一个是要由移动通信业来主导，一个是要有足够规模的市场。应由移动通信业主导据统计，全球使用WAP和GPRS的用户少得可怜，实在难以成市。WAP失败的原因不外乎是手机接口难以操作、联机速度慢、费用贵。首先是手机接口的问题。移动电话上本来就只有几个按钮，要输入中英文确实很不方便。看看日本的手机就设计得相当好，所谓的“拇指族”用一只…     

蓝牙三频GPRS手机─R520

在新加坡召开的CommunicAsia展览会上,爱立信推出了第一部使用蓝牙技术的GPRS（通用分组无线业务）三频电话手机──R520。R520融合了GPRS、高速数据（HSCSD）、蓝牙无线技术和WAP。R520带有一个WAP创览器,因此它是爱立信的第6款WAP手机。WAP（无线应用协议）是一种为了向无线设备用户提供互联网内容服务而开发的技术。GPRS将使移动互联网的成本更低、速度更快,而且对用户来说更易于操作。GPRS是GSM和TDMA（GPRS／EDGE）处理更高速的数据业务并是向第三代移动通信过渡的中间步骤。GPRS在普通GSM网络的传统电路…     

The Complementary Use of 3G WCDMA and GSM/GPRS Cellular Radio Networks

The traffic performance of integrated 3G wide-band code division multiple access (WCDMA) and GSM/GPRS network is evaluated. This type of network links two cellular radio systems which have different set of frequency bands and the same coverage size. The base station of 3G WCDMA is installed on an existing GSM/GPRS site. Dual-mode mobile terminals use handoff to establish calls on the better system. The soft handoff or inter-frequency hard handoff occurs when mobile terminals of 3G WCDMA or GSM/GPRS move between two adjacent cells, respectively. The inter-system hard handoffs are used between 3G WCDMA and GSM/GPRS systems. The data rate conversions between different systems, soft handoff region size, multiple data rate multimedia services, and the effect of the mobile terminal mobility on the user mean dwell time in each system are considered in the study. The simulation results demonstrate that a great traffic performance improvement on the complementary use of 3G WCDMA and GSM/GPRS cellular radio networks compared with the use of GSM/GPRS cellular radio networks. When high-data rate transmission is chosen for low-mobility subscribers, both the handoff failure probability, and carried traffic rates increase with the new call generation rate. However, both rates decrease conversely with the increasing new call generation rate as soon as the new call generation rate exceeds a critical value. This causes the integrated networks saturation. The higher mean speed for the mobile terminals produces lower new call blocking probabilities and total carried traffic. The new call blocking probabilities and total carried traffic increase with the size of the soft handoff region.     

GSM网络监测系统Abis接口信令的解码研究与实现

随着网络不断的成熟和网络承载业务量的不断增加,基于站址,站群的优化变得越来越困难。Abis接口的监测对于GSM,GPRS网优具有独特的优势。文章着重对Abis接口协议栈进行分析,并对该接口消息的解码方法进行了研究,提出GSM网络监测系统Abis接口解码模块设计的总体方案。最终的测试结果表明,该系统运行稳定且解码效率高。     

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.     

GPRS网络上MMS业务的实现方法

MMS是运行于GPRS承载网络之上的一个高层应用。而GPRS是在GSM Phase 2 阶段实现的内容，是对GSM网络的一个升级，把分组交换网络引入到了传统GSM的电路交换网络中，从而实现了宽带的移动数据通信。由于GPRS数据交换采用的是IP包交换的方式，从而把Internet网络从固定网延伸到了移动网，极大地改进了Internet网络的通讯接入方式，做到了随时随地都可以接入Internet网络。主要讨论无线终端接入GPRS网络以及MMS消息的具体实现方法。     

Wireless Internet access for mobile subscribers based on theGPRS/UMTS network

With the advent of IP technologies and the tremendous growth in data traffic, the wireless industry is evolving its core networks toward IP technology. Enabling wireless Internet access is one of the upcoming challenges for mobile radio network operators. The General Packet Radio Service is the packet-switched extension of GSM and was developed to facilitate access to IP-based services better than existing circuit-switched services provided by GSM. We illustrate how a visited mobile subscriber on a GPRS/UMTS network can access his/her home network via the gateway GPRS support node (GGSN). We also propose some implementation ideas on wireless Internet access for a remote mobile subscriber based on a GPRS/UMTS network     

Concepts, services, and protocols of the new GSM phase 2+ generalpacket radio service

For almost three years the European Telecommunications Standards Institute (ETSI) has been working on the specification of the general packet radio service (GPRS) for the Global System for Mobile Communications (GSM). In the course of 1997 standardization will come to an end, and a first introduction of GPRS by a service provider or network operator is likely to take place in 1999. The new service will accommodate data connections with variable bit rates and high bandwidth efficiency, and thus offers the possibility to attract a wide range of new applications to GSM networks. In this article possible applications and elementary concepts and service characteristics of GPRS are explained in detail. Furthermore, a medium access control protocol that conforms to the draft standard proposal for the GPRS air interface is introduced and analyzed. Thereafter, the simulation model is described and simulation results presented. The performance analysis carried out shows reasonable performance even under high load conditions     

WLAN接入GPRS核心网的认证机制

无线局域网和移动运营商网络结合起来，利用现有GPRS核心网强大的管理功能和漫游能力，可以拓展无线局域网的业务范围。这一方案中，只有控制信息被传输到移动核心网，而用户数据直接通过IP骨干网传输，这样可以极大地缓解无线数据业务对移动核心网的负荷。如何利用IP机制将移动用户认证信令从终端传到GPRS核心网是设计的难点。本着重分析认证机制及其相关协议。     

General Packet Radio Service (GPRS): architecture,interfaces, and deployment

This article provides an overview of General Packet Radio Service (GPRS). GPRS reuses the existing GSM infrastructure to provide end‐to‐end packet‐switched services. Benefits of GPRS include efficient radio usage, fast set‐up/access time and high bandwidth with multiple timeslots. GPRS also provides a smooth path for GSM evolution to the third generation mobile network. Specifically, a third generation network can continue to utilize the GPRS IP backbone network. We describe the GPRS network nodes and the interfaces among these nodes. Deployment issues for GPRS are also elaborated. Copyright © 2001 John Wiley & Sons, Ltd.     

无线应用协议(WAP)与通用分组无线业务(GPRS)技术

首先介绍了通用分组无线业务(CPRS)技术的功能业务、网络结构、协议模型,然后介绍无线应用协议(WAP)的基本原理以及一种GPRS中的WAP组网方案,最后得出结论WAP技术只有与GPRS结合才有利于WAP技术的发展.