wlan_propdel.ps.c

opnet环境中实现aodv路由协议建模

/* wlan_propdel.ps.c */                                                       
/* Modified for IEEE802.11										*/
/* Propagation delay model for radio link Transceiver Pipeline 	*/

/****************************************/
/*		  Copyright (c) 1993			*/
/*			by MIL 3, Inc.				*/
/*		(A Delaware Corporation)		*/
/*	3400 International Drive,  N.W.		*/
/*		Washington, D.C., U.S.A.		*/
/*			All Rights Reserved.		*/
/****************************************/

#include <opnet.h>


/***** constants *****/

/* propagation velocity of radio signal (m/s) */
#define	PROP_VELOCITY	3.0E+08

/* The variable defining a maximum range across which the station can communicate (meters)	*/ 
static double wlan_max_distance = OPC_DBL_INFINITY;

/***** pipeline procedure *****/
#if defined (__cplusplus)
extern "C"
#endif
void
wlan_propdel (pkptr)
	Packet*		pkptr;
	{
	double		start_prop_delay, end_prop_delay;
	double		start_prop_distance, end_prop_distance;


	/** Compute the propagation delay separating the	**/
	/** radio transmitter from the radio receiver.		**/
	FIN (wlan_propdel (pkptr));

	/* Get the start distance between transmitter and receiver. */
	start_prop_distance = op_td_get_dbl (pkptr, OPC_TDA_RA_START_DIST);

	/* Get the end distance between transmitter and receiver. */
	end_prop_distance = op_td_get_dbl (pkptr, OPC_TDA_RA_END_DIST);

	/* Compute propagation delay to start of reception. */
	start_prop_delay = start_prop_distance / PROP_VELOCITY;

	/* Compute propagation delay to end of reception. */
	end_prop_delay = end_prop_distance / PROP_VELOCITY;

	/* If the maximum transmission range of the station is not already set then extract	*/
	/* it from the user defined simulation attribute.									*/
	if (wlan_max_distance == OPC_DBL_INFINITY)
		{
		if (op_ima_sim_attr_exists ("Wireless LAN Range (meters)") == OPC_TRUE)
			{
			op_ima_sim_attr_get (OPC_IMA_DOUBLE, "Wireless LAN Range (meters)", &wlan_max_distance);
			}
		}

    /* If the starting and ending propagation distance is more than the maximum transmission	*/
	/* range then discard the packet in the pipeline stage. This will model the physical		*/
	/* transmission boundary of a wireless station.												*/ 
	if (end_prop_distance > wlan_max_distance || start_prop_distance > wlan_max_distance)
		{
		/* Discard the packet if the destination is more than the specified range	*/
		op_td_set_int (pkptr, OPC_TDA_RA_MATCH_STATUS, OPC_TDA_RA_MATCH_IGNORE);
		}

    /* Place both propagation delays in packet transmission data attributes. */
	op_td_set_dbl (pkptr, OPC_TDA_RA_START_PROPDEL, start_prop_delay);
	op_td_set_dbl (pkptr, OPC_TDA_RA_END_PROPDEL, end_prop_delay);
	FOUT;
	}