mac-802_11.h

ns2 中802.11 mac层的实现代码！

#define DSSS_CWMax			1023
#define DSSS_SlotTime			0.000020	// 20us
#define	DSSS_CCATime			0.000015	// 15us
#define DSSS_RxTxTurnaroundTime		0.000005	// 5us
#define DSSS_SIFSTime			0.000010	// 10us
#define DSSS_PreambleLength		144		// 144 bits
#define DSSS_PLCPHeaderLength		48		// 48 bits

class PHY_MIB {
public:
	u_int32_t	CWMin;
	u_int32_t	CWMax;
	double		SlotTime;
	double		CCATime;
	double		RxTxTurnaroundTime;
	double		SIFSTime;
	u_int32_t	PreambleLength;
	u_int32_t	PLCPHeaderLength;
};


/*
 * IEEE 802.11 Spec, section 11.4.4.2
 *      - default values for the MAC Attributes
 */
#define MAC_RTSThreshold		3000		// bytes
#define MAC_ShortRetryLimit		7		// retransmittions
#define MAC_LongRetryLimit		4		// retransmissions
#define MAC_FragmentationThreshold	2346		// bytes
#define MAC_MaxTransmitMSDULifetime	512		// time units
#define MAC_MaxReceiveLifetime		512		// time units

class MAC_MIB {
public:
	//		MACAddress;
	//		GroupAddresses;
	u_int32_t	RTSThreshold;
	u_int32_t	ShortRetryLimit;
	u_int32_t	LongRetryLimit;
	u_int32_t	FragmentationThreshold;
	u_int32_t	MaxTransmitMSDULifetime;
	u_int32_t	MaxReceiveLifetime;
	// wqos - Wed 04 Oct 00, 09:20 - dugdale
	u_int32_t dot11CFPollable;
	u_char    dot11CFPPeriod;
	u_int16_t dot11CFPMaxDuration;
	u_int16_t dot11BeaconPeriod;
	u_char    dot11DTIMPeriod;
	// wqos - changes by dugdale ends
	//		ManufacturerID;
	//		ProductID;

	u_int32_t	TransmittedFragmentCount;
	u_int32_t	MulticastTransmittedFrameCount;
	u_int32_t	FailedCount;	
	u_int32_t	RetryCount;
	u_int32_t	MultipleRetryCount;
	u_int32_t	FrameDuplicateCount;
	u_int32_t	RTSSuccessCount;
	u_int32_t	RTSFailureCount;
	u_int32_t	ACKFailureCount;
	u_int32_t	ReceivedFragmentCount;
	u_int32_t	MulticastReceivedFrameCount;
	u_int32_t	FCSErrorCount;
};


/* ======================================================================
   The following destination class is used for duplicate detection.
   ====================================================================== */
class Host {
public:
	LIST_ENTRY(Host) link;
	u_int32_t	index;
	u_int32_t	seqno;
};


// wqos - Thu 05 Oct 00, 13:36 - almquist
/* ======================================================================
   PCF List and utilities
   ====================================================================== */
class PCFPollElement{
public:
	inline PCFPollElement(int macId, int cfPollField):
		macId_(macId), cfPollField_(cfPollField), dontPoll_(0), next_(NULL){}
	int macId_;
	int cfPollField_;
	int dontPoll_;
	PCFPollElement *next_;
};

class PCFPollList{
public:
	PCFPollList();
	~PCFPollList();
	int getNextPollable();
	void insertNode(int macId, int cfPollable, int cfPollReq);
	int deleteNode(int macId);
	void initPoll();
	void markDontPoll(int macId);
	void clearDontPoll();
	int numPollable();
	
private:
	int nrOfNodes, onlyPollable;
	PCFPollElement *lastPollable, *lastPolled;
	PCFPollElement *firstElement, *lastElement;
};
// wqos - changes by almquist ends

/* ======================================================================
   The actual 802.11 MAC class.
   ====================================================================== */
class Mac802_11 : public Mac {
	friend class DeferTimer;
	friend class BackoffTimer;
	friend class IFTimer;
	friend class NavTimer;
	friend class RxTimer;
	friend class TxTimer;
	// wqos - Tue 26 Sep 00, 16:43 - dugdale
	friend class BeaconTimer;
	// wqos - changes by dugdale ends
public:
	Mac802_11(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);

protected:
	void	backoffHandler(void);
	void	deferHandler(void);
	void	navHandler(void);
	void	recvHandler(void);
	void	sendHandler(void);
	void	txHandler(void);
	// wqos - Tue 26 Sep 00, 16:43 - dugdale
	virtual void    beaconHandler(void);
	virtual void    pcfHandler(void);
	// wqos - changes by dugdale ends
	
private:
	int		command(int argc, const char*const* argv);

	/*
	 * Called by the timers.
	 */
	void		recv_timer(void);
	void		send_timer(void);
	int		check_pktCTRL();
	int		check_pktRTS();
	int		check_pktTx();
	// wqos - Tue 26 Sep 00, 17:04 - dugdale
	virtual int		check_pktPCF();
	// wqos - changes by dugdale ends
	
	/*
	 * Packet Transmission Functions.
	 */
	void	send(Packet *p, Handler *h);
	void 	sendRTS(int dst);
	void	sendCTS(int dst, double duration);
	void	sendACK(int dst);
	void	sendDATA(Packet *p);
	void	RetransmitRTS();
	void	RetransmitDATA();
	// wqos - Tue 26 Sep 00, 17:04 - dugdale
	void          send_beacon();
	void          sendPoll();
	void          sendCFEnd();
	void          pcfSend(int type, int subtype);
	// wqos - changes by dugdale ends

	/*
	 * Packet Reception Functions.
	 */
	void	recvRTS(Packet *p);
	void	recvCTS(Packet *p);
	void	recvACK(Packet *p);
	void	recvDATA(Packet *p);
	// wqos - Wed 29 Nov 00, 13:20 - dugdale
	void recvPoll(Packet *p);
	// wqos - changes by dugdale ends
	
	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);

	// wqos - Mon 09 Oct 00, 09:45 - dugdale
	void  do_cfp(); // Function to do a CFP... Remove this?
	// wqos - changes by dugdale ends
	
	/*
	 * 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);
	}
	inline double TX_Time(Packet *p) {
		double t = DATA_Time((HDR_CMN(p))->size());
		if(t < 0.0) {
			drop(p, "XXX");
			exit(1);
		}
		return t;
	}
	inline void inc_cw() {
		cw_ = (cw_ << 1) + 1;
		if(cw_ > phymib_->CWMax)
			cw_ = phymib_->CWMax;
	}
	inline void rst_cw() { cw_ = phymib_->CWMin; }
// wqos - Sat 18 Aug 01, 16:39 - dugdale
	inline u_int32_t usec(double t) {
		u_int32_t us = (u_int16_t)ceil(t *= 1e6);
		return us;
	}
// wqos - changes by dugdale ends

	// wqos - Thu 05 Oct 00, 10:42 - dugdale 
	// Converts seconds to TU
	inline u_int16_t tu(double t) {
		return (u_int16_t)ceil(t/0.001024);
	}
	
	// Converts TU to seconds
	inline double tutos(int t) {
		return (double)(t*0.001024);
	}
	// wqos - changes by dugdale ends
	
// wqos - Sat 18 Aug 01, 16:39 - dugdale
	inline void set_nav(u_int32_t us) {
// wqos - changes by dugdale ends
		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);
		}
	}

protected:
	PHY_MIB		*phymib_;
	MAC_MIB		*macmib_;

private:
	/*
	 * Mac Timers
	 */
	IFTimer		mhIF_;		// interface timer
	NavTimer	mhNav_;		// NAV timer
	RxTimer		mhRecv_;		// incoming packets
	TxTimer		mhSend_;		// outgoing packets
	// wqos - Tue 26 Sep 00, 16:46 - dugdale
	BeaconTimer     mhBeacon_;      // Beacon timer
	// wqos - changes by dugdale ends
	
	DeferTimer	mhDefer_;	// defer timer
	BackoffTimer	mhBackoff_;	// backoff timer

	/* ============================================================
	   Internal MAC State
	   ============================================================ */
	double		nav_;		// Network Allocation Vector

	MacState	rx_state_;	// incoming state (MAC_RECV or MAC_IDLE)
	MacState	tx_state_;	// outgoint state
	int		tx_active_;	// transmitter is ACTIVE

	Packet		*pktRTS_;	// outgoing RTS packet
	Packet		*pktCTRL_;	// outgoing non-RTS packet
	// wqos - Tue 10 Oct 00, 14:14 - dugdale 
	Packet          *pktPCF_;       // outgoing PCF stuff
	// wqos - changes by dugdale ends

	u_int32_t	cw_;		// Contention Window
	u_int32_t	ssrc_;		// STA Short Retry Count
	u_int32_t	slrc_;		// 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_;

	// wqos - Sat 30 Sep 00, 18:58 - dugdale
	// If this is non-zero then this is a PC
	int pc_;
	u_char dtimcount_, cfpcount_;
	int cfp_; // Non-zero during a CFP
	PCFPollList *pollList_;
	int pollsToSend_, btbs_;
	double lastPoll_;
	// wqos - changes by dugdale ends

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

#endif /* __mac_80211_h__ */