/* aodv_dra_power.ps.c */                                                       /* Default received power model for radio link Transceiver Pipeline *//****************************************//*  	  Copyright (c) 1993-2000		*//*      by OPNET Technologies, Inc.     *//*		(A Delaware Corporation)		*//*	3400 International Drive,  N.W.		*//*		Washington, D.C., U.S.A.		*//*			All Rights Reserved.		*//****************************************/#include "opnet.h"#include <math.h>/***** constants *****/#define C					3.0E+08			/* speed of light (m/s) */#define SIXTEEN_PI_SQ		157.91367		/* 16 times pi-squared */static const char*	PowI_Err_Hdr = "Error in radio power computation pipeline stage (aodv_dra_power):";/***** pipeline procedure *****/#if defined (__cplusplus)extern "C"#endifvoidaodv_dra_power (Packet * pkptr)	{	double		prop_distance, rcvd_power, path_loss;	double		tx_power, tx_base_freq, tx_bandwidth, tx_center_freq;	double		lambda, rx_ant_gain, tx_ant_gain;	Boolean		sig_lock;	Objid		rx_ch_obid;	double		in_band_tx_power, band_max, band_min;	double		rx_base_freq, rx_bandwidth;	/** Compute the average power in Watts of the		**/	/** signal associated with a transmitted packet.	**/	FIN (aodv_dra_power (pkptr));	/* If the incoming packet is 'valid', it may cause the receiver to	*/	/* lock onto it. However, if the receiving node is disabled, then	*/	/* the channel match should be set to noise.						*/	if (op_td_get_int (pkptr, OPC_TDA_RA_MATCH_STATUS) == OPC_TDA_RA_MATCH_VALID)		{		if (op_td_is_set (pkptr, OPC_TDA_RA_ND_FAIL))			{			/* The receiving node is disabled.  Change	*/			/* the channel match status to noise.		*/			op_td_set_int (pkptr, OPC_TDA_RA_MATCH_STATUS, OPC_TDA_RA_MATCH_NOISE);			}		else			{			/* The receiving node is enabled.  Get	*/			/* the address of the receiver channel.	*/			rx_ch_obid = op_td_get_int (pkptr, OPC_TDA_RA_RX_CH_OBJID);				/* If the receiver channel is already locked,		*/			/* the packet will now be considered to be noise.	*/			/* This prevents simultaneous reception of multiple	*/			/* valid packets on any given radio channel.		*/			if (op_ima_obj_attr_get (rx_ch_obid, "signal lock", &sig_lock)				== OPC_COMPCODE_FAILURE)				{				op_sim_end (PowI_Err_Hdr,					"Unable to get signal lock flag from channel attribute.",					OPC_NIL, OPC_NIL);				}					if (sig_lock)				op_td_set_int (pkptr, OPC_TDA_RA_MATCH_STATUS, OPC_TDA_RA_MATCH_NOISE);			else				{				/* Otherwise, the receiver channel will become	*/				/* locked until the packet reception ends.		*/				sig_lock = OPC_BOOLINT_ENABLED;				if (op_ima_obj_attr_set (rx_ch_obid, "signal lock", sig_lock)					== OPC_COMPCODE_FAILURE)					{					op_sim_end (PowI_Err_Hdr,						"Unable to set receiver channel attribute (signal lock).",						OPC_NIL, OPC_NIL);					}						}			}		}	/* Get power allotted to transmitter channel. */	tx_power = op_td_get_dbl (pkptr, OPC_TDA_RA_TX_POWER);	/* Get transmission frequency in Hz. */	tx_base_freq = op_td_get_dbl (pkptr, OPC_TDA_RA_TX_FREQ);	tx_bandwidth = op_td_get_dbl (pkptr, OPC_TDA_RA_TX_BW);	tx_center_freq = tx_base_freq + (tx_bandwidth / 2.0);	/* Caclculate wavelength (in meters). */	lambda = C / tx_center_freq;	/* Get distance between transmitter and receiver (in meters). */	prop_distance = op_td_get_dbl (pkptr, OPC_TDA_RA_START_DIST);	/* When using TMM, the TDA OPC_TDA_RA_RCVD_POWER will already	*/	/* have a raw value for the path loss. */	if (op_td_is_set (pkptr, OPC_TDA_RA_RCVD_POWER))		{		path_loss = op_td_get_dbl (pkptr, OPC_TDA_RA_RCVD_POWER);		}	else		{		/* Compute the path loss for this distance and wavelength. */		if (prop_distance > 0.0)			{			path_loss = (lambda * lambda) / 				(SIXTEEN_PI_SQ * prop_distance * prop_distance);			}		else			path_loss = 1.0;		}	/* Determine the receiver bandwidth and base frequency. */	rx_base_freq = op_td_get_dbl (pkptr, OPC_TDA_RA_RX_FREQ);	rx_bandwidth = op_td_get_dbl (pkptr, OPC_TDA_RA_RX_BW);	/* Use these values to determine the band overlap with the transmitter.	*/	/* Note that if there were no overlap at all, the packet would already	*/	/* have been filtered by the channel match stage.						*/	/* The base of the overlap band is the highest base frequency. */	if (rx_base_freq > tx_base_freq) 		band_min = rx_base_freq;	else		band_min = tx_base_freq;		/* The top of the overlap band is the lowest end frequency. */	if (rx_base_freq + rx_bandwidth > tx_base_freq + tx_bandwidth)		band_max = tx_base_freq + tx_bandwidth;	else		band_max = rx_base_freq + rx_bandwidth;	/* Compute the amount of in-band transmitter power. */	in_band_tx_power = tx_power * (band_max - band_min) / tx_bandwidth;	/* Get antenna gains (raw form, not in dB). */	tx_ant_gain = pow (10.0, op_td_get_dbl (pkptr, OPC_TDA_RA_TX_GAIN) / 10.0);	rx_ant_gain = pow (10.0, op_td_get_dbl (pkptr, OPC_TDA_RA_RX_GAIN) / 10.0);	/* Calculate received power level. */	rcvd_power = in_band_tx_power * tx_ant_gain * path_loss * rx_ant_gain;	/* Assign the received power level (in Watts) */	/* to the packet transmission data attribute. */	op_td_set_dbl (pkptr, OPC_TDA_RA_RCVD_POWER, rcvd_power);	FOUT;	}