NMT / DMS: User data facility support (required for SMS)

src/nmt/dms.h

@@ -0,0 +1,61 @@
+typedef struct nmt nmt_t;
+
+struct dms_frame {
+	struct dms_frame	*next;
+	uint8_t			s;			/* CT/DT frame */
+	uint8_t			n;			/* sequence number */
+	uint8_t			data[8];		/* data */
+};
+
+struct dms_state {
+	int			started;		/* did we start conversation ? */
+	int			rand_sent;		/* if we sent rand as an initiator? */
+	int			established;		/* DT frames after RAND (ack) */
+	int			tx_pending;		/* uper layer sent data, but not yet sent and acked */
+	uint8_t			n_r;			/* next expected frame to be received */
+	uint8_t			n_s;			/* next frame to be sent */
+	uint8_t			n_a;			/* next frame to be acked */
+	uint8_t			n_count;		/* counts frames that are stored in list */
+	uint8_t			dir;			/* direction */
+	int			eight_bits;		/* what mode are used for DT frames */
+	struct dms_frame	*frame_list;		/* list of frames to transmit */
+	int			send_rr;		/* RR must be sent next */
+};
+
+typedef struct dms {
+	/* DMS transmission */
+	int			frame_valid;		/* set, if there is a valid frame in sample buffer */
+	int16_t			*frame_spl;		/* 127 * fsk_bit_length */
+	int			frame_pos;		/* current sample position in frame_spl */
+	int			frame_length;		/* number of samples in frame_spl */
+	uint16_t		rx_sync;		/* shift register to detect sync */
+	double			rx_sync_level[256];	/* level infos */
+	double			rx_sync_quality[256];	/* quality infos */
+	int			rx_sync_count;		/* next bit to receive */
+	int			rx_in_sync;		/* if we are in sync and receive bits */
+	uint8_t			rx_frame[12];		/* receive frame, including label at the start and 3 words crc */
+	double			rx_frame_level[12];	/* level info */
+	double			rx_frame_quality[12];	/* quality info */
+	int			rx_bit_count;		/* next bit to receive */
+	int			rx_frame_count;		/* next character to receive */
+	struct {
+		uint8_t		d;			/* direction */
+		uint8_t		s;			/* selection */
+		uint8_t		p;			/* prefix */
+		uint8_t		n;			/* number of DT frame */
+	} rx_label;					/* used while receiving frame */
+
+	/* DMS protocol states */
+	struct dms_state	state;
+} dms_t;
+
+int dms_init_sender(nmt_t *nmt);
+void dms_cleanup_sender(nmt_t *nmt);
+int fsk_dms_frame(nmt_t *nmt, int16_t *samples, int length);
+void fsk_receive_bit_dms(nmt_t *nmt, int bit, double quality, double level);
+void dms_reset(nmt_t *nmt);
+
+void dms_send(nmt_t *nmt, const uint8_t *data, int length, int eight_bits);
+void dms_all_sent(nmt_t *nmt);
+void dms_receive(nmt_t *nmt, const uint8_t *data, int length, int eight_bits);
+