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来自「用C++编写的GPRS协议栈源代码」· HTML 代码 · 共 138 行
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<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"><!--Converted with LaTeX2HTML 96.1 (Feb 5, 1996) by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds --><HTML><HEAD><TITLE>The General Packet Radio Service - GPRS</TITLE><META NAME="description" CONTENT="The General Packet Radio Service - GPRS"><META NAME="keywords" CONTENT="gprs"><META NAME="resource-type" CONTENT="document"><META NAME="distribution" CONTENT="global"><LINK REL=STYLESHEET HREF="gprs.css"></HEAD><BODY LANG="EN"> <A NAME="tex2html62" HREF="node2.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="http://cbl.leeds.ac.uk/nikos/figs/next_motif.gif"></A> <A NAME="tex2html60" HREF="gprs.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="http://cbl.leeds.ac.uk/nikos/figs/up_motif.gif"></A> <A NAME="tex2html54" HREF="gprs.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="http://cbl.leeds.ac.uk/nikos/figs/previous_motif.gif"></A> <BR><B> Next:</B> <A NAME="tex2html63" HREF="node2.html">Configuration - How to </A><B>Up:</B> <A NAME="tex2html61" HREF="gprs.html">No Title</A><B> Previous:</B> <A NAME="tex2html55" HREF="gprs.html">No Title</A><BR> <P><H1><A NAME="SECTION00100000000000000000">The General Packet Radio Service - GPRS</A></H1><P>This chapter describes the implentation GSM/GPRS in <I>ns</I>. Only the MobileStation (MS) -BaseStation(BS) interactions are dealt with so far. The focus is onhandling of the radio resources and on the ntework stack ie the Link Layer(LL), the Radio Link Control (RLC) and the Medium Access Control (MAC)operating between the MS and the BS.<P> We allow for operation in a single cell. The BS may be interfaced withwired nodes (using hierarchical routing) to simulate the GPRS scenario.Traffic can be set-up in either direction from MS to BS or vice-versa. Thenumber of frequencies available in a cell can be varied by the user throughthe OTcl script. The maximum number of mobile nodes permissible in the cellcan also be set through the users' script.<P>Mobile nodes can be configured as GSM MS or GPRS MS. The difference here isthat GPRS MS release slots when there is no active packet transfer, whileGSM MS retain their slots till the call ends. Each MS can transmit/receiveonly on one frequency at a time. The BS however, can listen to/transmit onmany frequencies simultaneously.<P>In order to provide these, the LL, RLC and MAC layers have been implementedwith the following features<UL><LI> <B>LL</B>: Fragmentation and reassembly of higher layer PDUs; a stop-and-waitretransmit mechanism.<LI> <B>RLC</B>: Fragmentation and reassembly of LL PDUs; a selective retransmitmechanism.<LI> <B>MAC</B>: Separate uplink and downlink frequencies; TDMA frames with 8 time slotson each; slot allocation by request; symmetrically allocation of uplink anddownlink channels; slotrelease.</UL>These are further described in later sections.<P> The LL and RLC ack/fragmentation mechanisms can be used can be used withany other stack implementation (ie apart from GPRS) with minor modificationsas described later.<P>Note that for GSM/GPRS, we require the mobile nodes to be ``non-adhoc" ie theyshould communicate only with the BaseStation and not amongst themselves.The NOAH (Non-Adhoc ) routing agent may be used for this purpose and isincluded in this patch. Details can be found athttp://www.icsi.berkeley.edu/ widmer/mnav/ns-extension/<P><BR> <HR><UL> <LI> <A NAME="tex2html64" HREF="node2.html#SECTION00110000000000000000">Configuration - How to use the LL/RLC/MAC</A><LI> <A NAME="tex2html65" HREF="node3.html#SECTION00120000000000000000">MAC Implementation Details</A><UL> <LI> <A NAME="tex2html66" HREF="node4.html#SECTION00121000000000000000">Channels</A><LI> <A NAME="tex2html67" HREF="node5.html#SECTION00122000000000000000">TDMA Slot Structure</A><UL> <LI> <A NAME="tex2html68" HREF="node6.html#SECTION00122100000000000000">Timing Advance</A></UL> <LI> <A NAME="tex2html69" HREF="node7.html#SECTION00123000000000000000">Packet Transmission and Reception</A><LI> <A NAME="tex2html70" HREF="node8.html#SECTION00124000000000000000">Call Set-up and Handling</A><UL> <LI> <A NAME="tex2html71" HREF="node9.html#SECTION00124100000000000000">Resource Request</A><LI> <A NAME="tex2html72" HREF="node10.html#SECTION00124200000000000000">Resource Reply</A><LI> <A NAME="tex2html73" HREF="node11.html#SECTION00124300000000000000">Resource Release</A></UL> <LI> <A NAME="tex2html74" HREF="node12.html#SECTION00125000000000000000">Slot Handling</A><UL> <LI> <A NAME="tex2html75" HREF="node13.html#SECTION00125100000000000000">Allocation</A><LI> <A NAME="tex2html76" HREF="node14.html#SECTION00125200000000000000">Release</A></UL> <LI> <A NAME="tex2html77" HREF="node15.html#SECTION00126000000000000000">Dealing with Collisions</A><LI> <A NAME="tex2html78" HREF="node16.html#SECTION00127000000000000000">Error model</A><LI> <A NAME="tex2html79" HREF="node17.html#SECTION00128000000000000000">Handling ARPs</A><LI> <A NAME="tex2html80" HREF="node18.html#SECTION00129000000000000000">MacGprs class in C++</A><UL> <LI> <A NAME="tex2html81" HREF="node19.html#SECTION00129100000000000000">Storage Structures</A><LI> <A NAME="tex2html82" HREF="node20.html#SECTION00129200000000000000">Methods</A><LI> <A NAME="tex2html83" HREF="node21.html#SECTION00129300000000000000">Timers</A></UL> </UL> <LI> <A NAME="tex2html84" HREF="node22.html#SECTION00130000000000000000">Psuedocode for Packet Processing at MAC</A><UL> <LI> <A NAME="tex2html85" HREF="node23.html#SECTION00131000000000000000">Packet at MS MAC</A><LI> <A NAME="tex2html86" HREF="node24.html#SECTION00132000000000000000">Packet received at an BS</A><LI> <A NAME="tex2html87" HREF="node25.html#SECTION00133000000000000000">Accepting a packet from the IFQ </A><LI> <A NAME="tex2html88" HREF="node26.html#SECTION00134000000000000000">End of a Down Slot</A><LI> <A NAME="tex2html89" HREF="node27.html#SECTION00135000000000000000">End of a Up Slot</A><LI> <A NAME="tex2html90" HREF="node28.html#SECTION00136000000000000000">Packet to be transmitted onto the Air-Interface </A><LI> <A NAME="tex2html91" HREF="node29.html#SECTION00137000000000000000">Packet to be received from the Air-Interface</A><LI> <A NAME="tex2html92" HREF="node30.html#SECTION00138000000000000000">Packet send completed</A><LI> <A NAME="tex2html93" HREF="node31.html#SECTION00139000000000000000">Packet receive completed</A><LI> <A NAME="tex2html94" HREF="node32.html#SECTION001310000000000000000">A packet has to be passed to the RLC</A><LI> <A NAME="tex2html95" HREF="node33.html#SECTION001311000000000000000">Resources have to be alloted to an MS</A></UL> <LI> <A NAME="tex2html96" HREF="node34.html#SECTION00140000000000000000">Radio Link Control (RLC)</A><UL> <LI> <A NAME="tex2html97" HREF="node35.html#SECTION00141000000000000000">RLC class in C++</A><LI> <A NAME="tex2html98" HREF="node36.html#SECTION00142000000000000000">Parameters</A><LI> <A NAME="tex2html99" HREF="node37.html#SECTION00143000000000000000">Modifications for use outside GPRS</A><LI> <A NAME="tex2html100" HREF="node38.html#SECTION00144000000000000000">To bypass the RLC</A></UL> <LI> <A NAME="tex2html101" HREF="node39.html#SECTION00150000000000000000">Link Layer(LL)</A><UL> <LI> <A NAME="tex2html102" HREF="node40.html#SECTION00151000000000000000">LL class in C++</A><LI> <A NAME="tex2html103" HREF="node41.html#SECTION00152000000000000000">Parameters</A><LI> <A NAME="tex2html104" HREF="node42.html#SECTION00153000000000000000">Modifications for use outside GPRS/GSM</A></UL> <LI> <A NAME="tex2html105" HREF="node43.html#SECTION00160000000000000000">Commands at a glance</A><UL> <LI> <A NAME="tex2html106" HREF="node44.html#SECTION00161000000000000000">Configuration</A><LI> <A NAME="tex2html107" HREF="node45.html#SECTION00162000000000000000">Medium Access Control (MAC)</A><LI> <A NAME="tex2html108" HREF="node46.html#SECTION00163000000000000000">Radio Link Control (RLC)</A><LI> <A NAME="tex2html109" HREF="node47.html#SECTION00164000000000000000">Link Layer (LL)</A></UL></UL><HR><A NAME="tex2html62" HREF="node2.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="http://cbl.leeds.ac.uk/nikos/figs/next_motif.gif"></A> <A NAME="tex2html60" HREF="gprs.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="http://cbl.leeds.ac.uk/nikos/figs/up_motif.gif"></A> <A NAME="tex2html54" HREF="gprs.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="http://cbl.leeds.ac.uk/nikos/figs/previous_motif.gif"></A> <BR><B> Next:</B> <A NAME="tex2html63" HREF="node2.html">Configuration - How to </A><B>Up:</B> <A NAME="tex2html61" HREF="gprs.html">No Title</A><B> Previous:</B> <A NAME="tex2html55" HREF="gprs.html">No Title</A><P><ADDRESS><I>Richa Jain (96D07007) <BR>Tue Jul 24 22:29:53 IST 2001</I></ADDRESS></BODY></HTML>⌨️ 快捷键说明
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