1 | /************************************************************************************ |
---|
2 | * Copyright (C) 2008 by Politehnica University of Bucharest and Rutgers University |
---|
3 | * All rights reserved. |
---|
4 | * Refer to LICENSE for terms and conditions of use. |
---|
5 | ***********************************************************************************/ |
---|
6 | //Petroaca - Physical layer module |
---|
7 | package vnsim.network.dsrc; |
---|
8 | |
---|
9 | |
---|
10 | import java.util.List; |
---|
11 | |
---|
12 | import java.util.List; |
---|
13 | |
---|
14 | import vnsim.core.*; |
---|
15 | import vnsim.core.events.*; |
---|
16 | import vnsim.map.object.*; |
---|
17 | import vnsim.map.utils.*; |
---|
18 | import vnsim.network.propagation.*; |
---|
19 | |
---|
20 | |
---|
21 | |
---|
22 | |
---|
23 | public class WirelessPhy |
---|
24 | { |
---|
25 | private int stateMachine; |
---|
26 | |
---|
27 | private NoiseMonitor noiseMonitor; |
---|
28 | |
---|
29 | // the duration of a frame receive ; this time is taken from the crtTime in Engine.java |
---|
30 | private int currentTime; |
---|
31 | |
---|
32 | //the Signal to Interference/Noise Ratio of the current frame |
---|
33 | private double SINR; |
---|
34 | |
---|
35 | //if the ratio of the strongest sgignal to teh sum of the others is less tahn this value then they collide |
---|
36 | private double cpThreshold=Globals.CP_THRESHOLD; |
---|
37 | |
---|
38 | //if a frame has a receievd power below this value then it is too weak to be received. |
---|
39 | private double csThreshold; |
---|
40 | |
---|
41 | //if a frame has a received power below this value then it can be received by phy but it is corrupted |
---|
42 | private double rxThreshold; |
---|
43 | |
---|
44 | private double txPower=Globals.TRANSMITTER_POWER; |
---|
45 | |
---|
46 | private int propagationType=Engine.propagationModel; |
---|
47 | |
---|
48 | private double totalPower=0; |
---|
49 | |
---|
50 | private double maxPower=0; |
---|
51 | |
---|
52 | private double SINRThreshold=Globals.SINRThresholdBPSK; |
---|
53 | |
---|
54 | private int totalReceived; |
---|
55 | |
---|
56 | public WirelessPhy(int currentTime) |
---|
57 | { |
---|
58 | stateMachine=Globals.IDLE; |
---|
59 | |
---|
60 | noiseMonitor=new NoiseMonitor(fromDBmToW(Globals.ThermalNoise)); |
---|
61 | this.SINRThreshold=Globals.SINRThresholdBPSK; |
---|
62 | |
---|
63 | this.csThreshold=Globals.CS_THRESHOLD_S; |
---|
64 | this.rxThreshold=Globals.RX_THRESHOLD_S; |
---|
65 | |
---|
66 | this.currentTime=currentTime; |
---|
67 | |
---|
68 | this.totalReceived=0; |
---|
69 | } |
---|
70 | |
---|
71 | public ReceiveEvent recvFromChannel(List<ReceiveEvent> receivedSignals,int currentTime) |
---|
72 | { |
---|
73 | //DsrcFrame frame=new DsrcFrame(); |
---|
74 | int noSignals=0; |
---|
75 | |
---|
76 | |
---|
77 | //check stateMachine |
---|
78 | if(this.stateMachine==Globals.IDLE) |
---|
79 | { |
---|
80 | |
---|
81 | ReceiveEvent best=null; |
---|
82 | |
---|
83 | for(ReceiveEvent re : receivedSignals) |
---|
84 | { |
---|
85 | double receivedPower=0; |
---|
86 | |
---|
87 | Road r1 = (Road) Globals.map.roads.get(re.sender.getRoadIdx()); |
---|
88 | Point p1 = (Point) r1.points.get(re.sender.getPointIdx()); |
---|
89 | Road r2 = (Road) Globals.map.roads.get(re.receiver.getRoadIdx()); |
---|
90 | Point p2 = (Point) r2.points.get(re.receiver.getPointIdx()); |
---|
91 | |
---|
92 | double R = GPSutil.distance(p1, p2); |
---|
93 | |
---|
94 | R*=1000; |
---|
95 | |
---|
96 | switch(this.propagationType) |
---|
97 | { |
---|
98 | case Globals.SHADOWING :receivedPower=Shadowing.getPr(fromDBmToW(this.txPower),R,true); |
---|
99 | break; |
---|
100 | case Globals.TWO_RAY_GROUND: receivedPower=TwoRay.getPr(fromDBmToW(this.txPower),R); |
---|
101 | break; |
---|
102 | case Globals.RICEAN: receivedPower=Engine.riceanModule.getPr(fromDBmToW(this.txPower),R,currentTime); |
---|
103 | break; |
---|
104 | } |
---|
105 | |
---|
106 | if(receivedPower>this.csThreshold) |
---|
107 | { |
---|
108 | this.totalPower+=receivedPower; |
---|
109 | noSignals++; |
---|
110 | } |
---|
111 | |
---|
112 | if(receivedPower>this.maxPower) |
---|
113 | { |
---|
114 | maxPower=receivedPower; |
---|
115 | best=re; |
---|
116 | } |
---|
117 | |
---|
118 | if((re.getMessage())[0]==Globals.PROT_EMERGENCY) |
---|
119 | Globals.EMERGENCY_SENT++; |
---|
120 | } |
---|
121 | |
---|
122 | |
---|
123 | Globals.DSRC_PACKETS_TOTAL+=receivedSignals.size(); |
---|
124 | this.totalReceived+=noSignals; |
---|
125 | Globals.DSRC_PACKETS_LOST_WEAK+=(receivedSignals.size()-noSignals); |
---|
126 | |
---|
127 | if(best==null) |
---|
128 | return null; |
---|
129 | |
---|
130 | if(maxPower<this.csThreshold) |
---|
131 | { |
---|
132 | //weak signal |
---|
133 | this.noiseMonitor.addInterference(totalPower); |
---|
134 | return null; |
---|
135 | } |
---|
136 | else |
---|
137 | { |
---|
138 | this.noiseMonitor.addInterference(totalPower-maxPower); |
---|
139 | |
---|
140 | |
---|
141 | |
---|
142 | //can decode the preamble and phy header |
---|
143 | |
---|
144 | |
---|
145 | |
---|
146 | this.setSINR(maxPower); |
---|
147 | |
---|
148 | if(maxPower>this.rxThreshold) |
---|
149 | { |
---|
150 | |
---|
151 | //frame received ok |
---|
152 | |
---|
153 | this.stateMachine=Globals.RXing; |
---|
154 | // send frame to MAC |
---|
155 | Globals.DSRC_PACKETS_LOST_RX+=noSignals-1; |
---|
156 | return best; |
---|
157 | } |
---|
158 | else |
---|
159 | { |
---|
160 | |
---|
161 | if(!this.checkCollision(maxPower)) |
---|
162 | { |
---|
163 | //collision |
---|
164 | Globals.DSRC_PACKETS_LOST_COLLISION+=noSignals; |
---|
165 | this.noiseMonitor.addInterference(maxPower); |
---|
166 | return null; |
---|
167 | } |
---|
168 | //tag frame as corrupted and send to mac |
---|
169 | Globals.DSRC_PACKETS_LOST_CORRUPTED+=noSignals-1; |
---|
170 | best.setSender(null); |
---|
171 | return best; |
---|
172 | } |
---|
173 | |
---|
174 | } |
---|
175 | |
---|
176 | } |
---|
177 | |
---|
178 | //in transmit mode |
---|
179 | Globals.DSRC_PACKETS_LOST_TX+=receivedSignals.size(); |
---|
180 | return null; |
---|
181 | |
---|
182 | } |
---|
183 | |
---|
184 | public byte[] sendToChannel(byte[] message,int currentTime) |
---|
185 | { |
---|
186 | |
---|
187 | //if(this.stateMachine==Globals.IDLE) |
---|
188 | //{ |
---|
189 | //PCLP frame formation - make a packet out of the received frame |
---|
190 | //byte[] phyHeader=new byte[3]; |
---|
191 | //byte[] preamble=new byte[12]; |
---|
192 | //DsrcPacket packet=new DsrcPacket(preamble,phyHeader,new DsrcFrame()); |
---|
193 | |
---|
194 | //DSSS modulation |
---|
195 | |
---|
196 | this.stateMachine=Globals.TXing; |
---|
197 | return message; |
---|
198 | //} |
---|
199 | |
---|
200 | //return null; |
---|
201 | |
---|
202 | } |
---|
203 | |
---|
204 | // if the layer was transmitting or receiving a frame then after the duration of a frame it must return back to idle |
---|
205 | public void refreshFrameTime(int currentTime) |
---|
206 | { |
---|
207 | int ret; |
---|
208 | |
---|
209 | if(currentTime-this.currentTime>=Globals.WIRELESS_TRANSMISSION_FRAMES) |
---|
210 | { |
---|
211 | this.stateMachine=Globals.IDLE; |
---|
212 | this.noiseMonitor.refreshInterference(); |
---|
213 | this.totalPower=0; |
---|
214 | this.maxPower=0; |
---|
215 | |
---|
216 | if(currentTime%4==0) |
---|
217 | this.totalReceived=0; |
---|
218 | } |
---|
219 | |
---|
220 | this.currentTime=currentTime; |
---|
221 | } |
---|
222 | |
---|
223 | public NoiseMonitor getNoiseMonitor() |
---|
224 | { |
---|
225 | return this.noiseMonitor; |
---|
226 | } |
---|
227 | |
---|
228 | public DsrcPacket recvFromMac(DsrcFrame frame) |
---|
229 | { |
---|
230 | return null; |
---|
231 | } |
---|
232 | |
---|
233 | // calculates the SINR for the frame received |
---|
234 | public void setSINR(double receivedPower) |
---|
235 | { |
---|
236 | //this.SINR=10 * Math.log10(receivedPower/this.noiseMonitor.getInterference()); |
---|
237 | this.SINR=receivedPower/this.noiseMonitor.getInterference(); |
---|
238 | } |
---|
239 | |
---|
240 | public double getSINR() |
---|
241 | { |
---|
242 | return this.SINR; |
---|
243 | } |
---|
244 | |
---|
245 | |
---|
246 | //checks the ratio of the strongest signal to the rest to see if there is a collision |
---|
247 | public boolean checkCollision(double receivedPower) |
---|
248 | { |
---|
249 | if(receivedPower/(this.noiseMonitor.getInterference()-this.noiseMonitor.getThermalNoise())>this.cpThreshold) |
---|
250 | return true; |
---|
251 | |
---|
252 | return false; |
---|
253 | } |
---|
254 | |
---|
255 | // checks if the IAndN level is above the SINRThreshold |
---|
256 | public boolean checkInterferenceAndNoiseLevel() |
---|
257 | { |
---|
258 | if(this.noiseMonitor.getInterference()>=this.SINRThreshold) |
---|
259 | return false; |
---|
260 | |
---|
261 | return true; |
---|
262 | } |
---|
263 | |
---|
264 | public double fromDBmToW(double dbm) |
---|
265 | { |
---|
266 | return Math.pow(10, (dbm - 30) / 10); |
---|
267 | } |
---|
268 | |
---|
269 | public int getPropagation() |
---|
270 | { |
---|
271 | return this.propagationType; |
---|
272 | } |
---|
273 | |
---|
274 | public void setPropagation(int set) |
---|
275 | { |
---|
276 | this.propagationType=set; |
---|
277 | } |
---|
278 | |
---|
279 | public int getTotalReceivedPackets() |
---|
280 | { |
---|
281 | return this.totalReceived; |
---|
282 | } |
---|
283 | |
---|
284 | } |
---|