mac-802_11e.h

在网络仿真模拟工具下实现支持QoS的MAC层EDCF协议

/*
 *
 * Ported from CMU/Monarch's code, nov'98 -Padma.
 * wireless-mac-802_11.h
 */

#ifndef ns_mac_80211e_h
#define ns_mac_80211e_h

#include "priq.h"
#include "mac-timers_802_11e.h"
//#include "mac/mac-802_11.h"
#include "mac-802_11_226.h"
#include "marshall.h"
#include "iostream.h"

#define DEBUG 0
#define MAX_PRI 4 //max number of priority queues

#define GET_ETHER_TYPE(x)		GET2BYTE((x))
#define SET_ETHER_TYPE(x,y)            {u_int16_t t = (y); STORE2BYTE(x,&t);}
#define LEVEL(p) HDR_IP(p)->prio()
/* ======================================================================
   Frame Formats
   ====================================================================== */
/*
#define	MAC_ProtocolVersion	0x00

#define MAC_Type_Management	0x00
#define MAC_Type_Control	0x01
#define MAC_Type_Data		0x02
#define MAC_Type_Reserved	0x03

#define MAC_Subtype_RTS		0x0B
#define MAC_Subtype_CTS		0x0C
#define MAC_Subtype_ACK		0x0D
#define MAC_Subtype_Data	0x00
*/

/*
struct frame_control {
	u_char		fc_subtype		: 4;
	u_char		fc_type			: 2;
	u_char		fc_protocol_version	: 2;

	u_char		fc_order		: 1;
	u_char		fc_wep			: 1;
	u_char		fc_more_data		: 1;
	u_char		fc_pwr_mgt		: 1;
	u_char		fc_retry		: 1;
	u_char		fc_more_frag		: 1;
	u_char		fc_from_ds		: 1;
	u_char		fc_to_ds		: 1;
};

struct rts_frame {
	struct frame_control	rf_fc;
	u_int16_t		rf_duration;
	u_char			rf_ra[ETHER_ADDR_LEN];
	u_char			rf_ta[ETHER_ADDR_LEN];
	u_char			rf_fcs[ETHER_FCS_LEN];
};

struct cts_frame {
	struct frame_control	cf_fc;
	u_int16_t		cf_duration;
	u_char			cf_ra[ETHER_ADDR_LEN];
	u_char			cf_fcs[ETHER_FCS_LEN];
};

struct ack_frame {
	struct frame_control	af_fc;
	u_int16_t		af_duration;
	u_char			af_ra[ETHER_ADDR_LEN];
	u_char			af_fcs[ETHER_FCS_LEN];
};

// XXX This header does not have its header access function because it shares
// the same header space with hdr_mac.
struct hdr_mac802_11 {
	struct frame_control	dh_fc;
	u_int16_t		dh_duration;
	u_char			dh_da[ETHER_ADDR_LEN];
	u_char			dh_sa[ETHER_ADDR_LEN];
	u_char			dh_bssid[ETHER_ADDR_LEN];
	u_int16_t		dh_scontrol;
	u_char			dh_body[0]; // XXX Non-ANSI
};

*/
/* ======================================================================
   Definitions
   ====================================================================== */
/*
#define PLCP_HDR_LEN                            \
  	((phymib_->PreambleLength >> 3) +        \
 	 (phymib_->PLCPHeaderLength >> 3))

#define ETHER_HDR_LEN11				\
	(PLCP_HDR_LEN +				\
	 sizeof(struct hdr_mac802_11) +		\
	 ETHER_FCS_LEN)

#define ETHER_RTS_LEN				\
        (PLCP_HDR_LEN +				\
	 sizeof(struct rts_frame))

#define ETHER_CTS_LEN				\
         (PLCP_HDR_LEN +			\
         sizeof(struct cts_frame))

#define ETHER_ACK_LEN				\
         (PLCP_HDR_LEN +			\
	 sizeof(struct ack_frame))
*/
/*
 * IEEE 802.11 Spec, section 15.3.2
 *	- default values for the DSSS PHY MIB
 *
 * not taken from mac-802_11.h to have own PHY and MAC parameters
 * own class EDCF_PHY_MIB necessary, due to lack of CWmin and max values
 */

#define DSSS_EDCF_SlotTime			0.000020	// 20us
#define	DSSS_EDCF_CCATime		        0.000015	// 15us
#define DSSS_EDCF_RxTxTurnaroundTime		0.000005	// 5us
#define DSSS_EDCF_SIFSTime			0.000010	// 10us
#define DSSS_EDCF_PreambleLength	        144		// 144 bits
#define DSSS_EDCF_PLCPHeaderLength		48		// 48 bits
#define DSSS_EDCF_PLCPDataRate		1.0e6		// 1Mbps

/* Must account for propagation delays added by the channel model when
 * calculating tx timeouts (as set in tcl/lan/ns-mac.tcl).
 *   -- Gavin Holland, March 2002
 */
#define DSSS_EDCF_MaxPropagationDelay        0.000002        // 2us   XXXX

class EDCF_PHY_MIB {
public:
        double          SlotTime;
        double          CCATime;
        double          RxTxTurnaroundTime;
        double          SIFSTime;
        u_int32_t       PreambleLength;
        u_int32_t       PLCPHeaderLength;
        double          PLCPDataRate;
};


/*
 * IEEE 802.11 Spec, section 11.4.4.2
 *      - default values for the MAC Attributes
 */
#define MAC_EDCF_RTSThreshold		3000		// bytes
//#define MAC_EDCF_RTSThreshold		0		// bytes
#define MAC_EDCF_ShortRetryLimit	7		// retransmittions
#define MAC_EDCF_LongRetryLimit		4		// retransmissions
#define MAC_EDCF_FragmentationThreshold	2346		// bytes
#define MAC_EDCF_MaxTransmitMSDULifetime	512		// time units
#define MAC_EDCF_MaxReceiveLifetime		512		// time units


/* ======================================================================
   The actual 802.11e MAC class.
   ====================================================================== */
class Mac802_11e : public Mac {
	friend class DeferTimer_802_11e;
	friend class SIFSTimer_802_11e;
	friend class BackoffTimer_802_11e;
	friend class IFTimer_802_11e;
	friend class NavTimer_802_11e;
	friend class RxTimer_802_11e;
	friend class TxTimer_802_11e;
	friend class AkaroaTimer; 
public:
	Mac802_11e(EDCF_PHY_MIB* p, MAC_MIB *m);
	void		recv(Packet *p, Handler *h);
	inline int	hdr_dst(char* hdr, int dst = -2);
	inline int	hdr_src(char* hdr, int src = -2);
	inline int	hdr_type(char* hdr, u_int16_t type = 0);
	void setQ(PriQ* priqueue);	
	PriQ* queue_;  // for pointer to Queues in priq.cc
	double     getAIFS(int pri);
	void       defer_stop(int pri);
	void       calc_throughput();
	double     idle_time;
	
	int 	  rst_cw_mode_;
	
 protected:
	inline void transmit(Packet *p, double t);
	void	backoffHandler(int pri);
	void	deferHandler(int pri);
	void	navHandler(void);
	void	recvHandler(void);
	void	sendHandler(void);
	void	txHandler(void);
        // methods for priority-parameters
	int     getCW(int level);
	double interval_;

private:
	int   	command(int argc, const char*const* argv);
	bool     AIFSset;
	bool     CWset;
	int     cw_[MAX_PRI];
	int     cwmin_[MAX_PRI];
	int     cwmax_[MAX_PRI];
	double  txop_limit_[MAX_PRI];
	Handler*  callback_[MAX_PRI];
        
        /*
	 * Called by the timers.
	 */
	void		recv_timer(void);
	void		send_timer(void);
	int		check_pktCTRL(int pri);
	int		check_pktRTS(int pri);
	int		check_pktTx(int pri);
	int             levels;
	int             slotnum;
	double          aifs_[MAX_PRI];
	Packet*          packets_[MAX_PRI];
        
        /*
	 * Packet Transmission Functions.
	 */
	void	send(Packet *p, Handler *h);
	void 	sendRTS(int pri, int dst);
	void	sendCTS(int pri, int dst, double duration);
	void	sendACK(int pri, int dst);
	void	sendDATA(int pri, Packet *p);
	void	RetransmitRTS(int pri);
	void	RetransmitDATA(int pri);

	/*
	 * Packet Reception Functions.
	 */
	void	recvRTS(Packet *p);
	void	recvCTS(Packet *p);
	void	recvACK(Packet *p);
	void	recvDATA(Packet *p);

	void		capture(Packet *p);
	void		collision(Packet *p);
	void		discard(Packet *p, const char* why);
	void		rx_resume(void);
	void		tx_resume(void);

	inline int	is_idle(void);
	
	/*
	 * Debugging Functions.
	 */
	void		trace_pkt(Packet *p);
	void		dump(char* fname);

	inline int initialized() {
	    	return (phymib_ && macmib_ && cache_ && logtarget_ && Mac::initialized());
	}
	void mac_log(Packet *p) {
		logtarget_->recv(p, (Handler*) 0);
	}
	double txtime(Packet *p);
	double txtime(double psz, double drt);
	double txtime(int bytes) { /* clobber inherited txtime() */ abort(); }

	inline void inc_cw(int level) {
	    //get persistence factor
	    pf = queue_->pri_[level].getPF();
	    cw_old = cw_[level];
	    //calculate new cw_[pri] 
	    cw_[level] = ((cw_old + 1) * pf) - 1;
	    if(cw_[level] > cwmax_[level]) cw_[level] = cwmax_[level];
	}
	inline void rst_cw(int level) { 
		if(rst_cw_mode_==0)
			cw_[level] = cwmin_[level];
		else
			cw_[level] = int(0.9 * (cw_[level] - cwmin_[level]) * (cw_[level] - cwmin_[level])/ (cwmax_[level] - cwmin_[level])) + cwmin_[level];
        }

	inline double sec(double t) { return(t *= 1.0e-6); }
	inline u_int16_t usec(double t) {
		u_int16_t us = (u_int16_t)floor((t *= 1e6) + 0.5);
		/* u_int16_t us = (u_int16_t)rint(t *= 1e6); */
		return us;
	}
	inline void set_nav(u_int16_t us) {
		double now = Scheduler::instance().clock();
		double t = us * 1e-6;

		if((now + t) > nav_) {
			nav_ = now + t;
			if(mhNav_.busy()){
				mhNav_.stop();
				
			}
			mhNav_.start(t);
		}
	}

	inline void reset_eifs_nav();
	    
protected:
	EDCF_PHY_MIB   	*phymib_;
	MAC_MIB		*macmib_;

private:
	double          eifs_nav_;
	double		basicRate_;
 	double		dataRate_;
	int             numbytes_[MAX_PRI]; // for Akaroa Observation
	double          throughput;
	double          jitter;
	int             rtx_[MAX_PRI];
        int    pf;
	int cw_old;
	
	/*
	 * Contention Free Burst
	 */
	int     cfb_;
	int     cfb_broadcast;
	double  cfb_dur; 
	int     cfb_active;
	void    cfb(int pri);

	/*
	 * Mac Timers
	 */
	IFTimer_802_11e		mhIF_;          	// interface timer
	NavTimer_802_11e	mhNav_;		        // NAV timer
	RxTimer_802_11e		mhRecv_;		// incoming packets
	TxTimer_802_11e 	mhSend_;         	// outgoing packets

	DeferTimer_802_11e	mhDefer_;       	// defer timer
	SIFSTimer_802_11e       mhSifs_;                // defer timer for sifs, not stoppable!
	BackoffTimer_802_11e	mhBackoff_;	        // backoff timer
	AkaroaTimer             AK;
	/* ============================================================
	   Internal MAC State
	   ============================================================ */
	double		nav_;		// Network Allocation Vector

	MacState	rx_state_;	// incoming state (MAC_RECV or MAC_IDLE)
	MacState	tx_state_[MAX_PRI];	// outgoint state
	int		tx_active_;          	// transmitter is ACTIVE
	int		sending;          	// transmitter is ACTIVE
	Packet		*pktRTS_[MAX_PRI];	// outgoing RTS packet
	Packet		*pktCTRL_[MAX_PRI];	// outgoing non-RTS packet
        Packet          *pktTx_[MAX_PRI];
	//u_int32_t	cw_;		 // Contention Window
	u_int32_t	ssrc_[MAX_PRI];  // STA Short Retry Count
	u_int32_t	slrc_[MAX_PRI];  // STA Long Retry Count
	double		sifs_;		 // Short Interface Space
	double		pifs_;		 // PCF Interframe Space
	double		difs_;		 // DCF Interframe Space
	double		eifs_;  // Extended Interframe Space
	
        //double		tx_sifs_;
	//double		tx_pifs_;
	//double		tx_difs_;

	//int		min_frame_len_;

	NsObject*	logtarget_;

	/* ============================================================
	   Duplicate Detection state
	   ============================================================ */
	u_int16_t	sta_seqno_;	// next seqno that I'll use
	int		cache_node_count_;
	Host		*cache_;
};
#endif /* __mac_80211e_h__ */