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 - two ray propagation model |
---|
7 | package vnsim.network.propagation; |
---|
8 | |
---|
9 | import vnsim.map.object.Globals; |
---|
10 | import vnsim.network.propagation.FreeSpace; |
---|
11 | |
---|
12 | public class TwoRay |
---|
13 | { |
---|
14 | private static double Hr=Globals.AH; |
---|
15 | private static double Ht=Globals.AH; |
---|
16 | private static double crossoverDistance=(4*Math.PI*Ht*Hr)/Globals.DSRC_LAMBDA; |
---|
17 | |
---|
18 | public static double getPr(double Pt,double R) |
---|
19 | { |
---|
20 | if(Pt<=0.0 || R<=0.0) |
---|
21 | return -1; |
---|
22 | |
---|
23 | if(R<=crossoverDistance) |
---|
24 | { |
---|
25 | return FreeSpace.getPr(Pt,R); |
---|
26 | } |
---|
27 | else |
---|
28 | { |
---|
29 | double aux=Math.pow(Ht,2)*Math.pow(Hr,2); |
---|
30 | double R4=Math.pow(R,4); |
---|
31 | |
---|
32 | return (Pt*Math.pow(Globals.ANTENNA_GAIN,2)*aux)/(R4*Globals.SYSTEM_LOSS); |
---|
33 | } |
---|
34 | } |
---|
35 | |
---|
36 | public static double getPrAlt(double Pt,double R) |
---|
37 | { |
---|
38 | if(Pt<=0 || R<=0) |
---|
39 | return -1; |
---|
40 | |
---|
41 | double pathloss = -(2*Globals.ANTENNA_GAIN); |
---|
42 | double freeSpace = (4.0 * Math.PI * R) / Globals.DSRC_LAMBDA; |
---|
43 | double planeEarth = (R * R) / (Hr*Ht); |
---|
44 | |
---|
45 | if (planeEarth > freeSpace){ |
---|
46 | pathloss += 20.0 * Math.log10(planeEarth); |
---|
47 | }else{ |
---|
48 | pathloss += 20.0 * Math.log10(freeSpace); |
---|
49 | } |
---|
50 | |
---|
51 | return Pt-pathloss; |
---|
52 | } |
---|
53 | } |
---|