wlan_chanmatch.ps.c

在OPNET中实现AODV路由协议

/* wlan_chanmatch.ps.c */                                                       
/* Modified for IEEE802.11									*/
/* Channel match 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"


#if defined (__cplusplus)
extern "C"
#endif
void
wlan_chanmatch (Packet * pkptr)
	{
	double		tx_freq, tx_bw, tx_drate, tx_code;
	double		rx_freq, rx_bw, rx_drate, rx_code;
	Vartype		tx_mod;
	Vartype		rx_mod;

	/** Determine the compatibility between transmitter and receiver channels. **/
	FIN (wlan_chanmatch (pkptr));

	/* Obtain transmitting channel attributes. */
	tx_freq		= op_td_get_dbl (pkptr, OPC_TDA_RA_TX_FREQ);
	tx_bw		= op_td_get_dbl (pkptr, OPC_TDA_RA_TX_BW);
	tx_drate	= op_td_get_dbl (pkptr, OPC_TDA_RA_TX_DRATE);
	tx_code		= op_td_get_dbl (pkptr, OPC_TDA_RA_TX_CODE);
	tx_mod		= op_td_get_ptr (pkptr, OPC_TDA_RA_TX_MOD);	

	/* Obtain receiving channel attributes. */
	rx_freq		= op_td_get_dbl (pkptr, OPC_TDA_RA_RX_FREQ);
	rx_bw		= op_td_get_dbl (pkptr, OPC_TDA_RA_RX_BW);
	rx_drate	= op_td_get_dbl (pkptr, OPC_TDA_RA_RX_DRATE);
	rx_code		= op_td_get_dbl (pkptr, OPC_TDA_RA_RX_CODE);
	rx_mod		= op_td_get_ptr (pkptr, OPC_TDA_RA_RX_MOD);	

	/* For non-overlapping bands, the packet has no	*/
	/* effect; such packets are ignored entirely.	*/
	if ((tx_freq > rx_freq + rx_bw) || (tx_freq + tx_bw < rx_freq))
		{
		op_td_set_int (pkptr, OPC_TDA_RA_MATCH_STATUS, OPC_TDA_RA_MATCH_IGNORE);
		FOUT;
		}

    /* If the transmitter and receiver data rate do not match then drop the packet.	*/
    if (tx_drate != rx_drate)
    	{
		op_td_set_int (pkptr, OPC_TDA_RA_MATCH_STATUS, OPC_TDA_RA_MATCH_IGNORE); 
		FOUT;
		}
	
	/* Otherwise check for channel attribute mismatches which would	*/
	/* cause the in-band packet to be considered as noise.			*/
	if ((tx_freq != rx_freq) || (tx_bw != rx_bw) || 
		(tx_code != rx_code) || (tx_mod != rx_mod))
		{
		op_td_set_int (pkptr, OPC_TDA_RA_MATCH_STATUS, OPC_TDA_RA_MATCH_NOISE);
		FOUT;
		}

	/* Otherwise the packet is considered a valid transmission which	*/
	/* could eventually be accepted at the error correction stage.		*/
	op_td_set_int (pkptr, OPC_TDA_RA_MATCH_STATUS, OPC_TDA_RA_MATCH_VALID);

	FOUT;
	}