GPRS核心網路模擬系統之研究

Research of GPRS Core Network Emulation System

陳建彰(Chien-Chang Chen)

指導教授 ： 張世杰

元智大學/工程學院/通訊工程學系/碩士(2005年)

摘要

GPRS(General Packet Radio Service)目前仍是行動通訊的主流，其核心網路主要是包括SGSN(Serving GPRS Support Node),GGSN(Gateway GPRS Support Node)兩大部分，透過此兩大部分可以來進行訊息傳遞和封包轉換，就算是3G行動網路系統，其核心網路也是參照GPRS網路發展而來的。

本論文的目的就是利用現成的伺服器和網路卡，以Linux作業系統為核心，修改現有OpenGGSN所提供的開放式GGSN與SGSNEmu的原始碼，再加上本論文新研發的手機模擬器(Mobile Station Emulator-MS Emu)以經濟而有效地發展出GPRS核心網路系統研發平台以做為GPRS之基礎。根據此平台可以來研究GPRS訊息傳遞，如:建立/回應PDP(Packet Data Protocal)請求等，或者實際上傳遞IP封包，透過Ethereal網路分析軟體可以來了解GPRS封包轉換的程序。

根據此論文中所開發的平台，了解到真實GPRS網路實際運作的情形，然後再更進一步去修改它，使它可適用於3G WCDMA，無線都會網路及其他多擷取網路，成為更有價值的研究發展平台。

關鍵字

手機模擬器 ； 伺服器 ； 網路卡

並列摘要

This thesis presents a discussion of using off-the-shelf server hardware and network interface cards and OpenGGSN source codes to cost-effectively build a GPRS core network emulation system. Using this emulation system, a research on GPRS message communication flow was carried out. This includes GPRS attach request, activate PDP (Packet Data Protocol) context request, create PDP context request, create PDP context response and data packet delivery. A discussion of utilizing a network protocol analyzer called ‘Ethereal’ to analyze and visualize GPRS message/data packets flow within this system is also presented. Finally, problems encountered with OpenGGSN and solutions are also discussed.

This research produces two products: the YZU GPRS core network emulation system and a Linux-based GGSN prototype. The former includes a Mobile Station Emulator (MSemu) that can cost-effectively emulate multiple Mobile Stations. MSemu is a new product of this research.

With appropriate modifications, this emulation system can be extended to 3G cellular network, wireless local/metropolitan area networks and other multiple access networks, to become a very valuable research and development platform.

並列關鍵字

Ethereal ； OpenGGSN ； SGSN ； GGSN ； MS Emu

參考文獻

[2] Yi-Bing Lin and I. Chlamtac, ”Wireless and Mobile Network Architectures ”, John Wiley & Sons, Inc, 2001.

[5] Sanders, Geoffrey,“ GPRS Networks ”, Wiley, 2003.

[8] W.Richard Stevens, ”UNIX Network Programming: The Sockets Networking API, 3e ”, Addison-Wesley, 2004.

[1] OpenGGSN- Open Source GPRS Core Network, http://www.openggsn.org/.

[3] 3GPP.3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; General Packet Radio Service(GPRS); Service description; Stage 2(Release 6). Technical Specification 3GPP TS 23.060 version 6.4.0 (2004-03).