14 files changed, 714 insertions, 170 deletions

diff --git a/gsm-tvoid/src/lib/Makefile.am b/gsm-tvoid/src/lib/Makefile.am
index 2d4d7f7..88b8faa 100755..100644
--- a/gsm-tvoid/src/lib/Makefile.am
+++ b/gsm-tvoid/src/lib/Makefile.am
@@ -37,16 +37,17 @@ ourpython_PYTHON =			\
 ourlib_LTLIBRARIES = _gsm.la
 
 # These are the source files that go into the shared library
-_gsm_la_SOURCES = 			\
+_gsm_la_SOURCES = 		\
 	gsmstack.c			\
-	interleave.c			\
+	interleave.c		\
 	conv.c				\
 	sch.c				\
 	cch.c				\
 	gsm.cc				\
-	gsm_burst.cc			\
-	gsm_burst_ff.cc			\
-	gsm_burst_cf.cc
+	gsm_burst.cc		\
+	gsm_burst_ff.cc		\
+	gsm_burst_cf.cc		\
+	gsm_burst_sink_c.cc
 	
 
 # magic flags
@@ -62,16 +63,17 @@ gsm.cc gsm.py: $(LOCAL_IFILES) $(ALL_IFILES)
 	$(SWIG) $(SWIGPYTHONARGS) -module gsm -o gsm.cc $(LOCAL_IFILES) 
 
 # These headers get installed in ${prefix}/include/gnuradio
-grinclude_HEADERS =			\
+grinclude_HEADERS =		\
 	gsm_burst.h			\
 	gsmstack.h			\
-	interleave.h			\
+	interleave.h		\
 	conv.h				\
 	sch.h				\
 	cch.h				\
 	system.h			\
-	gsm_burst_ff.h			\
-	gsm_burst_cf.h			\
+	gsm_burst_ff.h		\
+	gsm_burst_cf.h		\
+	gsm_burst_sink_c.h	\
 	gsm_constants.h
 
 
diff --git a/gsm-tvoid/src/lib/gsm.i b/gsm-tvoid/src/lib/gsm.i
index d990e8b..106e378 100755
--- a/gsm-tvoid/src/lib/gsm.i
+++ b/gsm-tvoid/src/lib/gsm.i
@@ -9,6 +9,7 @@
 //#include "gsm_burst.h"
 #include "gsm_burst_ff.h"
 #include "gsm_burst_cf.h"
+#include "gsm_burst_sink_c.h"
 //#include <stdexcept>
 
 %}
@@ -43,6 +44,10 @@
 
 #define CLK_CORR_TRACK		0x00000010		//adjust timing based on correlation offsets
 
+#define BURST_CB_SYNC_OFFSET	1
+#define BURST_CB_ADJ_OFFSET		2
+#define BURST_CB_TUNE			3
+
 //EQ options
 enum EQ_TYPE {
 	EQ_NONE,
@@ -73,6 +78,8 @@ public:
 	long			d_unknown_count;
 	long			d_total_count;
 	
+	long 			next_arfcn;
+
 	int				sync_state();
 	float 			last_freq_offset(void);
 	double 			mean_freq_offset(void);
@@ -81,24 +88,32 @@ public:
 	void full_reset(void);
 
 protected:
-	gsm_burst();  
+	gsm_burst(gr_feval_ll *);  
 };
 
 
 GR_SWIG_BLOCK_MAGIC(gsm,burst_ff);
-gsm_burst_ff_sptr gsm_make_burst_ff ();
+gsm_burst_ff_sptr gsm_make_burst_ff (gr_feval_ll *);
 
 class gsm_burst_ff : public gr_block, public gsm_burst {
 private:
-	gsm_burst_ff ();
+	gsm_burst_ff (gr_feval_ll *);
 };
 
 GR_SWIG_BLOCK_MAGIC(gsm,burst_cf);
-gsm_burst_cf_sptr gsm_make_burst_cf (float);
+gsm_burst_cf_sptr gsm_make_burst_cf (gr_feval_ll *,float);
 
 class gsm_burst_cf : public gr_block, public gsm_burst {
 private:
-	gsm_burst_cf (float);
+	gsm_burst_cf (gr_feval_ll *,float);
+};
+
+GR_SWIG_BLOCK_MAGIC(gsm,burst_sink_c);
+gsm_burst_sink_c_sptr gsm_make_burst_sink_c(gr_feval_ll *,float);
+
+class gsm_burst_sink_c : public gr_sync_block, public gsm_burst {
+private:
+	gsm_burst_sink_c (gr_feval_ll *,float);
 };
 
 
diff --git a/gsm-tvoid/src/lib/gsm_burst.cc b/gsm-tvoid/src/lib/gsm_burst.cc
index b862d69..14950c6 100755
--- a/gsm-tvoid/src/lib/gsm_burst.cc
+++ b/gsm-tvoid/src/lib/gsm_burst.cc
@@ -13,12 +13,15 @@
 #include "gsmstack.h"
 
 
-gsm_burst::gsm_burst () :
+gsm_burst::gsm_burst (gr_feval_ll *t) :
+		p_tuner(t),
 		d_clock_options(DEFAULT_CLK_OPTS),
 		d_print_options(0),
 		d_equalizer_type(EQ_FIXED_DFE)
 {
  
+//	fprintf(stderr,"gsm_burst: enter constructor (t=%8.8x)\n",(unsigned int)t);
+	  	
 //	M_PI = M_PI; //4.0 * atan(1.0); 
 
 	full_reset();
@@ -348,14 +351,15 @@ void gsm_burst::shift_burst(int shift_bits)
 //of the mean phase  from pi/2.
 void gsm_burst::calc_freq_offset(void) 
 {
-	int start = d_burst_start + 10;
-	int end = d_burst_start + USEFUL_BITS - 10;
+	const int padding = 20;
+	int start = d_burst_start + padding;
+	int end = d_burst_start + USEFUL_BITS - padding;
 	
 	float sum = 0.0;
 	for (int j = start; j <= end; j++) {
 		sum += d_burst_buffer[j];
 	}
-	float mean = sum / ((float)USEFUL_BITS - 20.0);
+	float mean = sum / ((float)USEFUL_BITS - (2.0 * (float)padding) );
 	
 	float p_off = mean - (M_PI / 2);
 	d_freq_offset = p_off * 1625000.0 / (12.0 * M_PI);
@@ -466,7 +470,8 @@ float gsm_burst::correlate_pattern(const float *pattern,const int pat_size,const
 		corr = 0.0;
 		for (int i = 1; i < pat_size; i++) {	//Start a 1 to skip first bit due to diff encoding
 			//d_corr[j+distance] += d_burst_buffer[center+i+j] * pattern[i];
-			corr += SIGNUM(d_burst_buffer[center+i+j]) * pattern[i];  //binary corr/sliced
+			//corr += SIGNUM(d_burst_buffer[center+i+j]) * pattern[i];  //binary corr/sliced
+			corr += d_burst_buffer[center+i+j] * pattern[i];
 		}
 		corr /= pat_size - 1; //normalize, -1 for skipped first bit
 		if (corr > d_corr_max) {
@@ -609,8 +614,9 @@ int gsm_burst::get_burst(void)
 		case PARTIAL_SCH:
 			d_sync_state = WAIT_SCH;
 			break;
-		case SCH:
-			d_sync_state = SYNCHRONIZED;
+		//case SCH:
+		//let the burst type switch handle this so it knows if new or old sync
+		//	d_sync_state = SYNCHRONIZED;
 		break;
 		default:
 			break;
@@ -645,6 +651,18 @@ int gsm_burst::get_burst(void)
 		d_ts = 0;		//TODO: check this
 		break;
 	case SCH:
+#ifndef TEST_TUNE_TIMING
+		//TODO: it would be better to adjust tuning on first FCCH (for better SCH detection),
+		//		but tuning can run away with false FCCHs
+		//		Some logic to retune back to original offset on false FCCH might work
+		if (p_tuner) {
+			if (SYNCHRONIZED == d_sync_state)
+				p_tuner->calleval(BURST_CB_ADJ_OFFSET);
+			else
+				p_tuner->calleval(BURST_CB_SYNC_OFFSET);
+				
+		}
+#endif
 		d_burst_count++;
 		d_sch_count++;
 		d_last_sch = d_burst_count;
@@ -672,7 +690,6 @@ int gsm_burst::get_burst(void)
 		d_last_good = d_burst_count;
 	}
 
-
 	//Check for loss of sync
 	int bursts_since_good = d_burst_count - d_last_good;
 	if (bursts_since_good > MAX_SYNC_WAIT) {
@@ -686,6 +703,47 @@ int gsm_burst::get_burst(void)
 		//print info
 		print_burst();
 
+		/////////////////////
+		//start tune testing
+#ifdef TEST_TUNE_TIMING
+
+		static int good_count = -1; //-1: wait sch, >=0: got sch, counting
+		static int wait_count = 0;
+			
+		if (UNKNOWN == d_burst_type) {
+			if (good_count >= 0) {
+				fprintf(stdout,"good_count: %d\n",good_count);
+	
+				if (p_tuner) {
+					next_arfcn = TEST_TUNE_GOOD_ARFCN;
+					p_tuner->calleval(BURST_CB_TUNE);
+				}
+			}
+			good_count = -1;	// start again at resync
+	
+		} else {
+	
+			if (good_count >= 0 ) {
+				good_count++;
+			}
+	
+			if (SCH == d_burst_type) {	
+				if ((good_count < 0) && (++wait_count > 20)) {	// get some good syncs before trying again
+					fprintf(stdout,"restarting good_count\n");
+					good_count = wait_count = 0;
+					//tune away
+					if (p_tuner) { 
+						next_arfcn = TEST_TUNE_EMPTY_ARFCN;
+						p_tuner->calleval(BURST_CB_TUNE);
+					}
+				}
+			}
+		}
+#endif
+		//end tune testing	
+		/////////////////////
+
+
 		//Adjust the buffer write position to align on MAX_CORR_DIST
 		if ( d_clock_options & CLK_CORR_TRACK )
 			d_bbuf_pos += MAX_CORR_DIST - d_burst_start;
diff --git a/gsm-tvoid/src/lib/gsm_burst.h b/gsm-tvoid/src/lib/gsm_burst.h
index def20e0..48fafac 100755
--- a/gsm-tvoid/src/lib/gsm_burst.h
+++ b/gsm-tvoid/src/lib/gsm_burst.h
@@ -8,10 +8,15 @@
 
 #include "gsm_constants.h"
 #include <gr_math.h>
-//#include <Python.h>		//for callback testing
 #include <gr_feval.h>
 #include "gsmstack.h"
 
+//Testing Modes
+//Tune test measures hopping latency by hopping between good and empty ARFCNs
+#undef TEST_TUNE_TIMING
+#define TEST_TUNE_GOOD_ARFCN	658
+#define TEST_TUNE_EMPTY_ARFCN	655
+
 
 //Console printing options
 #define PRINT_NOTHING		0x00000000
@@ -73,13 +78,18 @@ enum EQ_TYPE {
 	EQ_VITERBI
 };
 
+#define BURST_CB_SYNC_OFFSET	1
+#define BURST_CB_ADJ_OFFSET		2
+#define BURST_CB_TUNE			3
+
+
 class gsm_burst;
 
 class gsm_burst
 {
 protected:
 	
-	gsm_burst();  
+	gsm_burst(gr_feval_ll *t);  
 
 	//Burst Buffer: Storage for burst data
 	float			d_burst_buffer[BBUF_SIZE];
@@ -116,30 +126,33 @@ protected:
 	double			d_freq_off_sum;
 	double			d_freq_off_weight;
 
+	gr_feval_ll 	*p_tuner;
+	
 	//////// Methods
 	int				get_burst(void);
 	BURST_TYPE		get_fcch_burst(void);
 	BURST_TYPE		get_sch_burst(void);
 	BURST_TYPE		get_norm_burst(void);
 	
-	void	shift_burst(int);
-	void	calc_freq_offset(void); 
-	void	equalize(void);
-	float	correlate_pattern(const float *,const int,const int,const int);
-	void	diff_decode_burst(void);
+	virtual void	shift_burst(int);
+	void			calc_freq_offset(void); 
+	virtual void	equalize(void);
+	float			correlate_pattern(const float *,const int,const int,const int);
+	void			diff_decode_burst(void);
 
-	void	sync_reset(void);
+	void			sync_reset(void);
 
-	void	print_bits(const float *data,int length);
-	void	print_hex(const unsigned char *data,int length);
-	void	soft2hardbit(char *dst, const float *data, int len);
-	void	print_burst(void);
+	void			print_bits(const float *data,int length);
+	void			print_hex(const unsigned char *data,int length);
 
-	void	diff_encode(const float *in,float *out,int length,float lastbit = 1.0);	
-	void	diff_decode(const float *in,float *out,int length,float lastbit = 1.0);	
+//	void			soft2hardbit(char *dst, const float *data, int len);	//need this?
+	void			print_burst(void);
+
+	void			diff_encode(const float *in,float *out,int length,float lastbit = 1.0);	
+	void			diff_decode(const float *in,float *out,int length,float lastbit = 1.0);	
 
 public:
-	~gsm_burst ();	
+	virtual 		~gsm_burst ();	
 
 	////// General Stats
 	//TODO: Maybe there should be a burst_stats class?
@@ -157,12 +170,17 @@ public:
 	unsigned long	d_print_options;
 	EQ_TYPE			d_equalizer_type;
 	
-	int sync_state() { return d_sync_state;}
-	float last_freq_offset() {return d_freq_offset;}
-	double mean_freq_offset(void);
 	
 	//Methods
 	void full_reset(void);
+
+	int sync_state() { return d_sync_state;}
+
+	//Frequency
+	float last_freq_offset() {return d_freq_offset;}
+	double mean_freq_offset(void);
+
+	long next_arfcn;
 };
 
 
diff --git a/gsm-tvoid/src/lib/gsm_burst_cf.cc b/gsm-tvoid/src/lib/gsm_burst_cf.cc
index a91c569..a584cd6 100755
--- a/gsm-tvoid/src/lib/gsm_burst_cf.cc
+++ b/gsm-tvoid/src/lib/gsm_burst_cf.cc
@@ -9,21 +9,23 @@
 #include <stdio.h>
 #include <gri_mmse_fir_interpolator_cc.h>
 
-gsm_burst_cf_sptr gsm_make_burst_cf (float sample_rate)
+gsm_burst_cf_sptr gsm_make_burst_cf (gr_feval_ll *t,float sample_rate)
 {
-  return gsm_burst_cf_sptr (new gsm_burst_cf (sample_rate));
+  return gsm_burst_cf_sptr (new gsm_burst_cf (t,sample_rate));
 }
 
 static const int MIN_IN = 1;	// minimum number of input streams
 static const int MAX_IN = 1;	// maximum number of input streams
-static const int MIN_OUT = 1;	// minimum number of output streams
+static const int MIN_OUT = 0;	// minimum number of output streams
 static const int MAX_OUT = 1;	// maximum number of output streams
 
-gsm_burst_cf::gsm_burst_cf (float sample_rate) : 
+gsm_burst_cf::gsm_burst_cf (gr_feval_ll *t, float sample_rate) : 
+	gsm_burst(t),
 	gr_block (	"burst_cf",
 				gr_make_io_signature (MIN_IN, MAX_IN, sizeof (gr_complex)),
 				gr_make_io_signature (MIN_OUT, MAX_OUT, USEFUL_BITS * sizeof (float))),
 	d_clock_counter(0.0),
+	d_mu(0.5),
 	d_last_sample(0.0,0.0),
 	d_interp(new gri_mmse_fir_interpolator_cc())
 
@@ -36,7 +38,7 @@ gsm_burst_cf::gsm_burst_cf (float sample_rate) :
 	fprintf(stderr,"Sample interval      : %e\n",d_sample_interval);
 	fprintf(stderr,"Relative sample rate : %g\n",d_relative_sample_rate);
 		
-	set_history(4); 
+	set_history(4); //need history for interpolator
 	
 }
 
@@ -63,41 +65,39 @@ int gsm_burst_cf::general_work (int noutput_items,
 	
 	int ii=0;
 	int rval = 0;  //default to no output
+	int do_output = output_items.size() > 0 ? 1 : 0;
 
 	int ninput = ninput_items[0];
 	//fprintf(stderr,"#i=%d/#o=%d",n_input,noutput_items);
 
-	int  ni = ninput - d_interp->ntaps();  // interpolator need -4/+3 samples NTAPS = 8
+	int  ni = ninput - d_interp->ntaps() - 16;  // interpolator need -4/+3 samples NTAPS = 8  , - 16 for safety margin
 	
 	while (( rval < noutput_items) && ( ii < ni ) ) {
 		//clock symbols 
 		//TODO: this is very basic and can be improved.  Need tracking...
 		//TODO: use burst_start offsets as timing feedback
 		//TODO: save complex samples for Viterbi EQ
-		if ( d_clock_counter >= GSM_SYMBOL_PERIOD) {
-
-			d_clock_counter -= GSM_SYMBOL_PERIOD; //reset clock for next sample, keep the remainder
-
-			//float mu = 1.0 - d_clock_counter / GSM_SYMBOL_PERIOD;
-			float mu = d_clock_counter / GSM_SYMBOL_PERIOD;
-			gr_complex sample = d_interp->interpolate (&in[ii], mu);	//FIXME: this seems noisy, make sure it is being used correctly
+		
+		//from m&m
+		gr_complex sample = d_interp->interpolate (&in[ii], d_mu);	//FIXME: this seems noisy, make sure it is being used correctly
+		
+		gr_complex conjprod = sample * conj(d_last_sample);
+		float diff_angle = gr_fast_atan2f(imag(conjprod), real(conjprod));
 
-			gr_complex conjprod = sample * conj(d_last_sample);
-			float diff_angle = gr_fast_atan2f(imag(conjprod), real(conjprod));
+		d_last_sample = sample;
 
-			d_last_sample = sample;
-	
-			assert(d_bbuf_pos <= BBUF_SIZE );
-			
-			if (d_bbuf_pos >= 0)	//could be negative offset from burst alignment.  TODO: perhaps better just to add some padding to the buffer
-				d_burst_buffer[d_bbuf_pos] = diff_angle;
-			
-			d_bbuf_pos++;
-			
-			if ( d_bbuf_pos >= BBUF_SIZE ) { 
-			
-				if (get_burst()) {
-					//found a burst, send to output
+		assert(d_bbuf_pos <= BBUF_SIZE );
+		
+		if (d_bbuf_pos >= 0)	//could be negative offset from burst alignment.  TODO: perhaps better just to add some padding to the buffer
+			d_burst_buffer[d_bbuf_pos] = diff_angle;
+		
+		d_bbuf_pos++;
+		
+		if ( d_bbuf_pos >= BBUF_SIZE ) { 
+		
+			if (get_burst()) {
+				//found a burst, send to output
+				if (do_output) {
 					//ensure that output data is in range
 					int b = d_burst_start;
 					if (b < 0)
@@ -106,31 +106,36 @@ int gsm_burst_cf::general_work (int noutput_items,
 						b = 2 * MAX_CORR_DIST - 1;
 		
 					memcpy(out+rval*USEFUL_BITS, d_burst_buffer + b, USEFUL_BITS*sizeof(float));
-					rval++;
-
-					switch ( d_clock_options & QB_MASK ) {
-					case QB_QUARTER: //extra 1/4 bit each burst
-						d_clock_counter -= GSM_SYMBOL_PERIOD / 4.0; 
-						break;
-					case QB_FULL04:	//extra bit on timeslot 0 & 4
-						if (!(d_ts%4))
-							d_clock_counter -= GSM_SYMBOL_PERIOD; 
-						break;
-					case QB_NONE:	//don't adjust for quarter bits at all
-					default:
-						break;
-					}
-					
-					d_last_burst_s_count = d_sample_count;	
-					
-					//fprintf(stderr,"clock: %f, pos: %d\n",d_clock_counter,d_bbuf_pos);
 				}
-			}	   
-		}
-
-		d_clock_counter += d_sample_interval;
-		d_sample_count++;
- 		ii++;
+				rval++;
+				
+				switch ( d_clock_options & QB_MASK ) {
+				case QB_QUARTER: //extra 1/4 bit each burst
+					d_mu -= d_relative_sample_rate / 4.0;
+					//d_clock_counter -= GSM_SYMBOL_PERIOD / 4.0; 
+					break;
+				case QB_FULL04:	//extra bit on timeslot 0 & 4
+					if (!(d_ts%4))
+						d_mu -= d_relative_sample_rate;
+						//d_clock_counter -= GSM_SYMBOL_PERIOD; 
+					break;
+				case QB_NONE:	//don't adjust for quarter bits at all
+				default:
+					break;
+				}
+				
+				d_last_burst_s_count = d_sample_count;
+				
+				//fprintf(stderr,"clock: %f, pos: %d\n",d_clock_counter,d_bbuf_pos);
+			}
+		}	   
+		
+		//TODO: timing adjust
+		//d_mu = d_mu + d_omega + d_gain_mu * mm_val;
+		d_mu += d_relative_sample_rate;
+		ii += (int)floor(d_mu);
+		d_sample_count += (int)floor(d_mu);
+		d_mu -= floor(d_mu);
 	}
 	
 	//fprintf(stderr,"/ii=%d/rval=%d\n",ii,rval);
diff --git a/gsm-tvoid/src/lib/gsm_burst_cf.h b/gsm-tvoid/src/lib/gsm_burst_cf.h
index 33f61f6..40ccc83 100755
--- a/gsm-tvoid/src/lib/gsm_burst_cf.h
+++ b/gsm-tvoid/src/lib/gsm_burst_cf.h
@@ -8,7 +8,7 @@ class gsm_burst_cf;
 
 typedef boost::shared_ptr<gsm_burst_cf> gsm_burst_cf_sptr;
 
-gsm_burst_cf_sptr gsm_make_burst_cf(float);
+gsm_burst_cf_sptr gsm_make_burst_cf(gr_feval_ll *,float);
 
 class gri_mmse_fir_interpolator_cc;
 
@@ -16,15 +16,17 @@ class gsm_burst_cf : public gr_block, public gsm_burst
 {
 private:
 	
-	friend gsm_burst_cf_sptr gsm_make_burst_cf(float);
-	gsm_burst_cf(float);  
+	friend gsm_burst_cf_sptr gsm_make_burst_cf(gr_feval_ll *,float);
+	gsm_burst_cf(gr_feval_ll *,float);  
 	
 	//clocking parameters
-	float			d_relative_sample_rate;
 	double			d_sample_interval;
 	double			d_clock_counter;
 	gr_complex		d_last_sample;
 
+	float			d_relative_sample_rate;		//omega
+	float			d_mu;
+	
 	gri_mmse_fir_interpolator_cc 	*d_interp;  //sub-sample interpolator from GR
 		
 public:
diff --git a/gsm-tvoid/src/lib/gsm_burst_ff.cc b/gsm-tvoid/src/lib/gsm_burst_ff.cc
index 2980829..dd449f1 100755
--- a/gsm-tvoid/src/lib/gsm_burst_ff.cc
+++ b/gsm-tvoid/src/lib/gsm_burst_ff.cc
@@ -9,17 +9,18 @@
 #include <stdio.h>
 #include <gri_mmse_fir_interpolator_cc.h>
 
-gsm_burst_ff_sptr gsm_make_burst_ff ()
+gsm_burst_ff_sptr gsm_make_burst_ff (gr_feval_ll *t)
 {
-  return gsm_burst_ff_sptr (new gsm_burst_ff());
+  return gsm_burst_ff_sptr (new gsm_burst_ff(t));
 }
 
 static const int MIN_IN = 1;	// minimum number of input streams
 static const int MAX_IN = 1;	// maximum number of input streams
-static const int MIN_OUT = 1;	// minimum number of output streams
+static const int MIN_OUT = 0;	// minimum number of output streams
 static const int MAX_OUT = 1;	// maximum number of output streams
 
-gsm_burst_ff::gsm_burst_ff () : 
+gsm_burst_ff::gsm_burst_ff (gr_feval_ll *t) : 
+	gsm_burst(t),
 	gr_block(	"burst_ff",
 				gr_make_io_signature (MIN_IN, MAX_IN, sizeof (float)),
 				gr_make_io_signature (MIN_OUT, MAX_OUT, USEFUL_BITS * sizeof (float)))
@@ -37,7 +38,7 @@ void gsm_burst_ff::forecast (int noutput_items, gr_vector_int &ninput_items_requ
 {
   unsigned ninputs = ninput_items_required.size ();
   for (unsigned i = 0; i < ninputs; i++)
-    ninput_items_required[i] = noutput_items * BBUF_SIZE + history();
+    ninput_items_required[i] = noutput_items * BBUF_SIZE;
 }
 
 
@@ -51,9 +52,10 @@ int gsm_burst_ff::general_work (int noutput_items,
 	
 	int ii=0;
 	int rval = 0;  //default to no output
-
+	int do_output = output_items.size() > 0 ? 1 : 0;
+	
 	int n_input = ninput_items[0];
-	//fprintf(stderr,"#i=%d/#o=%d",n_input,noutput_items);
+//	fprintf(stderr,"out=%8.8x/#i=%d/#o=%d",(unsigned)out,n_input,noutput_items);
 
 	while (( rval < noutput_items) && ( ii < n_input ) ) {
 
@@ -68,15 +70,16 @@ int gsm_burst_ff::general_work (int noutput_items,
 		
 			if (get_burst()) {
 				//found a burst, send to output
-
-				//ensure that output data is in range
-				int b = d_burst_start;
-				if (b < 0)
-					b = 0;
-				else if (b >= 2 * MAX_CORR_DIST)
-					b = 2 * MAX_CORR_DIST - 1;
-	
-				memcpy(out+rval*USEFUL_BITS, d_burst_buffer + b, USEFUL_BITS*sizeof(float));
+				if (do_output) {
+					//ensure that output data is in range
+					int b = d_burst_start;
+					if (b < 0)
+						b = 0;
+					else if (b >= 2 * MAX_CORR_DIST)
+						b = 2 * MAX_CORR_DIST - 1;
+		
+					memcpy(out+rval*USEFUL_BITS, d_burst_buffer + b, USEFUL_BITS*sizeof(float));
+				}
 				rval++;
 
 				switch ( d_clock_options & QB_MASK  ) {
@@ -98,7 +101,7 @@ int gsm_burst_ff::general_work (int noutput_items,
  		ii++;
 	}
 	
-	//fprintf(stderr,"/ii=%d/rval=%d\n",ii,rval);
+//	fprintf(stderr,"/ii=%d/rval=%d\n",ii,rval);
 
 	consume_each (ii);
 	
diff --git a/gsm-tvoid/src/lib/gsm_burst_ff.h b/gsm-tvoid/src/lib/gsm_burst_ff.h
index 30c10dc..8ca61ef 100755
--- a/gsm-tvoid/src/lib/gsm_burst_ff.h
+++ b/gsm-tvoid/src/lib/gsm_burst_ff.h
@@ -8,14 +8,14 @@ class gsm_burst_ff;
 
 typedef boost::shared_ptr<gsm_burst_ff> gsm_burst_ff_sptr;
 
-gsm_burst_ff_sptr gsm_make_burst_ff();
+gsm_burst_ff_sptr gsm_make_burst_ff(gr_feval_ll *);
 
 class gsm_burst_ff : public gr_block, public gsm_burst
 {
 private:
 	
-	friend gsm_burst_ff_sptr gsm_make_burst_ff();
-	gsm_burst_ff();  
+	friend gsm_burst_ff_sptr gsm_make_burst_ff(gr_feval_ll *);
+	gsm_burst_ff(gr_feval_ll *t);  
 	
 public:
 	~gsm_burst_ff ();	
diff --git a/gsm-tvoid/src/lib/gsm_burst_ff_single.cc b/gsm-tvoid/src/lib/gsm_burst_ff_single.cc
new file mode 100755
index 0000000..ff6c354
--- /dev/null
+++ b/gsm-tvoid/src/lib/gsm_burst_ff_single.cc
@@ -0,0 +1,118 @@
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gsm_burst_ff.h>
+#include <gr_io_signature.h>
+#include <gr_math.h>
+#include <stdio.h>
+#include <gri_mmse_fir_interpolator_cc.h>
+
+gsm_burst_ff_sptr gsm_make_burst_ff (gr_feval_ll *t)
+{
+  return gsm_burst_ff_sptr (new gsm_burst_ff(t));
+}
+
+static const int MIN_IN = 1;	// minimum number of input streams
+static const int MAX_IN = 1;	// maximum number of input streams
+static const int MIN_OUT = 0;	// minimum number of output streams
+static const int MAX_OUT = 1;	// maximum number of output streams
+
+gsm_burst_ff::gsm_burst_ff (gr_feval_ll *t) : 
+	gsm_burst(t),
+	gr_block(	"burst_ff",
+				gr_make_io_signature (MIN_IN, MAX_IN, sizeof (float)),
+//				gr_make_io_signature (MIN_OUT, MAX_OUT, USEFUL_BITS * sizeof (float)))
+				gr_make_io_signature (0, 0, 0))
+//				gr_make_io_signature (MIN_OUT, MAX_OUT, sizeof (float)))
+{
+		
+	set_history(1); 
+	
+}
+
+gsm_burst_ff::~gsm_burst_ff ()
+{
+}
+
+/*
+void gsm_burst_ff::forecast (int noutput_items, gr_vector_int &ninput_items_required)
+{
+  unsigned ninputs = ninput_items_required.size ();
+  for (unsigned i = 0; i < ninputs; i++)
+    ninput_items_required[i] = noutput_items * BBUF_SIZE + history();
+}
+*/
+
+int gsm_burst_ff::general_work (int noutput_items,
+				   gr_vector_int &ninput_items,
+				   gr_vector_const_void_star &input_items,
+				   gr_vector_void_star &output_items)
+{
+	const float *in = (const float *) input_items[0];
+	float *out = (float *) output_items[0];
+	
+	int ii=0;
+	//int rval = 0;  //default to no output
+	int rval = noutput_items;  //default to no output
+
+	//int do_output = output_items.size() > 0 ? 1 : 0;
+	int do_output = 0;
+	
+	int n_input = ninput_items[0];
+//	fprintf(stderr,"out=%8.8x/#i=%d/#o=%d",(unsigned)out,n_input,noutput_items);
+//	fprintf(stderr,"#i=%d/#o=%d",n_input,noutput_items);
+
+//	while (( rval < noutput_items) && ( ii < n_input ) ) {
+	while ( ii < n_input ) {
+
+		assert(d_bbuf_pos <= BBUF_SIZE );
+		
+		if (d_bbuf_pos >= 0)	//could have been offset negative.  TODO: perhaps better just to add some slack to the buffer
+			d_burst_buffer[d_bbuf_pos] = in[ii];
+		
+		d_bbuf_pos++;
+		
+		if ( d_bbuf_pos >= BBUF_SIZE ) { 
+		
+			if (get_burst()) {
+				//found a burst, send to output
+				if (do_output) {
+					//ensure that output data is in range
+					int b = d_burst_start;
+					if (b < 0)
+						b = 0;
+					else if (b >= 2 * MAX_CORR_DIST)
+						b = 2 * MAX_CORR_DIST - 1;
+		
+					memcpy(out+rval*USEFUL_BITS, d_burst_buffer + b, USEFUL_BITS*sizeof(float));
+				}
+				//rval++;
+				//rval += USEFUL_BITS*sizeof(float);
+
+				switch ( d_clock_options & QB_MASK  ) {
+				case QB_QUARTER: //Can't do this in the FF version
+				case QB_FULL04:	//extra bit on timeslot 0 & 4
+					if (!(d_ts%4))
+						d_bbuf_pos--;
+					break;
+				case QB_NONE:	//don't adjust for quarter bits at all
+				default:
+					break;
+				}
+
+				d_last_burst_s_count = d_sample_count;	
+
+			}
+		}
+		d_sample_count++;
+ 		ii++;
+	}
+	
+//	fprintf(stderr,"/ii=%d/rval=%d\n",ii,rval);
+
+	consume_each (ii);
+	
+	return rval;
+}
diff --git a/gsm-tvoid/src/lib/gsm_burst_ff_single.h b/gsm-tvoid/src/lib/gsm_burst_ff_single.h
new file mode 100755
index 0000000..553fe65
--- /dev/null
+++ b/gsm-tvoid/src/lib/gsm_burst_ff_single.h
@@ -0,0 +1,31 @@
+#ifndef INCLUDED_GSM_BURST_FF_H
+#define INCLUDED_GSM_BURST_FF_H
+
+#include <gr_block.h>
+#include <gsm_burst.h>
+
+class gsm_burst_ff;
+
+typedef boost::shared_ptr<gsm_burst_ff> gsm_burst_ff_sptr;
+
+gsm_burst_ff_sptr gsm_make_burst_ff(gr_feval_ll *);
+
+class gsm_burst_ff : public gr_block, public gsm_burst
+{
+private:
+	
+	friend gsm_burst_ff_sptr gsm_make_burst_ff(gr_feval_ll *);
+	gsm_burst_ff(gr_feval_ll *t);  
+	
+public:
+	~gsm_burst_ff ();	
+
+//	void forecast (int noutput_items, gr_vector_int &ninput_items_required);
+	
+	int general_work (	int noutput_items,
+						gr_vector_int &ninput_items,
+						gr_vector_const_void_star &input_items,
+						gr_vector_void_star &output_items);
+};
+
+#endif /* INCLUDED_GSM_BURST_FF_H */
diff --git a/gsm-tvoid/src/lib/gsm_burst_sink_c.cc b/gsm-tvoid/src/lib/gsm_burst_sink_c.cc
new file mode 100755
index 0000000..58787bb
--- /dev/null
+++ b/gsm-tvoid/src/lib/gsm_burst_sink_c.cc
@@ -0,0 +1,141 @@
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "gsm_burst_sink_c.h"
+#include <gr_io_signature.h>
+#include <gr_math.h>
+#include <stdio.h>
+#include <gri_mmse_fir_interpolator_cc.h>
+
+gsm_burst_sink_c_sptr gsm_make_burst_sink_c (gr_feval_ll *t,float sample_rate)
+{
+  return gsm_burst_sink_c_sptr (new gsm_burst_sink_c(t,sample_rate));
+}
+
+static const int MIN_IN = 1;	// minimum number of input streams
+static const int MAX_IN = 1;	// maximum number of input streams
+
+gsm_burst_sink_c::gsm_burst_sink_c (gr_feval_ll *t, float sample_rate) : 
+	gsm_burst(t),
+	gr_sync_block (	"burst_sink_c",
+				gr_make_io_signature (MIN_IN, MAX_IN, sizeof (gr_complex)),
+				gr_make_io_signature (0,0,0)
+			),
+	d_clock_counter(0.0),
+	d_mu(0.5),
+	d_last_sample(0.0,0.0),
+	d_ii(0),
+	d_interp(new gri_mmse_fir_interpolator_cc())
+
+{
+
+	//clocking parameters
+	d_sample_interval = 1.0 / sample_rate;
+	d_relative_sample_rate = sample_rate / GSM_SYMBOL_RATE;
+	
+	fprintf(stderr,"Sample interval      : %e\n",d_sample_interval);
+	fprintf(stderr,"Relative sample rate : %g\n",d_relative_sample_rate);
+	
+	//we need history for interpolator taps and some saftey relative to relative rate
+	int hist = d_interp->ntaps(); // + 16;  // interpolator need -4/+3 samples NTAPS = 8  , 16 for safety margin
+	set_history(hist); //need history for interpolator
+	
+}
+
+gsm_burst_sink_c::~gsm_burst_sink_c ()
+{
+	delete d_interp;
+}
+
+void gsm_burst_sink_c::shift_burst(int shift_bits)
+{
+	//fprintf(stderr,"sft:%d\n",shift_bits);
+
+	assert(shift_bits >= 0);
+	assert(shift_bits < BBUF_SIZE );
+
+	gr_complex *p_src = d_complex_burst + shift_bits;
+	gr_complex *p_dst = d_complex_burst;
+	int num = BBUF_SIZE - shift_bits;
+	
+	memmove(p_dst,p_src,num * sizeof(gr_complex));  //need memmove because of overlap
+
+	//DON'T adjust the buffer positions, the superclass method will do that...
+	//d_bbuf_pos -= shift_bits;
+	//call the parent method to shift the float version
+	gsm_burst::shift_burst(shift_bits);
+}
+
+//TODO: put everything but GR stuff in a common complex type class (share w/ gsm_burst_cf)
+int gsm_burst_sink_c::work(int noutput_items,
+		gr_vector_const_void_star &input_items,
+		gr_vector_void_star &output_items)
+
+{
+	const gr_complex *in = (const gr_complex *) input_items[0];
+	
+//	fprintf(stderr,"#o=%d",noutput_items);
+
+	assert( d_ii >= 0 );
+
+	while ( d_ii < noutput_items ) {
+		//clock symbols 
+
+		gr_complex sample = d_interp->interpolate (&in[d_ii], d_mu);
+		
+		gr_complex conjprod = sample * conj(d_last_sample);
+		float diff_angle = gr_fast_atan2f(imag(conjprod), real(conjprod));
+
+		d_last_sample = sample;
+
+#if 1		
+		assert(d_bbuf_pos <= BBUF_SIZE );
+		
+		if (d_bbuf_pos >= 0) {	//could be negative offset from burst alignment.  TODO: perhaps better just to add some padding to the buffer
+			d_burst_buffer[d_bbuf_pos] = diff_angle;
+			d_complex_burst[d_bbuf_pos] = sample;
+		}
+		
+		d_bbuf_pos++;
+		
+		if ( d_bbuf_pos >= BBUF_SIZE ) { 
+			if (get_burst()) {
+				//adjust timing
+				//TODO: generate timing error from burst buffer (phase & freq)
+							
+				switch ( d_clock_options & QB_MASK ) {
+				case QB_QUARTER: //extra 1/4 bit each burst
+					d_mu -= d_relative_sample_rate / 4.0;
+					break;
+				case QB_FULL04:	//extra bit on timeslot 0 & 4
+					if (!(d_ts%4))
+						d_mu -= d_relative_sample_rate;
+					break;
+				case QB_NONE:	//don't adjust for quarter bits at all
+				default:
+					break;
+				}
+				
+				d_last_burst_s_count = d_sample_count;
+				
+				//fprintf(stderr,"clock: %f, pos: %d\n",d_clock_counter,d_bbuf_pos);
+			}
+		}	   
+#endif			
+
+		d_mu += d_relative_sample_rate;
+		d_ii += (int)floor(d_mu);
+		//d_sample_count += (int)floor(d_mu);		//TODO: outside loop?
+		d_mu -= floor(d_mu);
+	}
+
+	//reset d_ii, accounting for advance
+	d_ii -= noutput_items;
+	
+//	fprintf(stderr,"/mu=%f",d_mu);
+//	fprintf(stderr,"/ii=%d\n",d_ii);
+
+	return noutput_items;
+}
diff --git a/gsm-tvoid/src/lib/gsm_burst_sink_c.h b/gsm-tvoid/src/lib/gsm_burst_sink_c.h
new file mode 100755
index 0000000..1197a2c
--- /dev/null
+++ b/gsm-tvoid/src/lib/gsm_burst_sink_c.h
@@ -0,0 +1,54 @@
+#ifndef INCLUDED_gsm_burst_sink_c_H
+#define INCLUDED_gsm_burst_sink_c_H
+
+#include <gr_sync_block.h>
+#include <gsm_burst.h>
+
+class gsm_burst_sink_c;
+
+typedef boost::shared_ptr<gsm_burst_sink_c> gsm_burst_sink_c_sptr;
+
+gsm_burst_sink_c_sptr gsm_make_burst_sink_c(gr_feval_ll *,float);
+
+class gri_mmse_fir_interpolator_cc;
+
+//class gsm_burst_sink_c : public gr_block, public gsm_burst
+class gsm_burst_sink_c : public gr_sync_block, public gsm_burst
+{
+private:
+	
+	friend gsm_burst_sink_c_sptr gsm_make_burst_sink_c(gr_feval_ll *,float);
+	gsm_burst_sink_c(gr_feval_ll *,float);  
+	
+	//clocking parameters
+	double			d_sample_interval;
+	double			d_clock_counter;
+	gr_complex		d_last_sample;
+
+	float			d_relative_sample_rate;		//omega
+	float			d_mu;
+	int				d_ii;	//save index between work calls for interp advance
+	
+	gri_mmse_fir_interpolator_cc 	*d_interp;  //sub-sample interpolator from GR
+	
+	gr_complex		d_complex_burst[BBUF_SIZE];
+
+	void 			shift_burst(int shift_bits);
+		
+public:
+	~gsm_burst_sink_c ();	
+
+//	void forecast (int noutput_items, gr_vector_int &ninput_items_required);
+
+	int work(int noutput_items,
+				gr_vector_const_void_star &input_items,
+				gr_vector_void_star &output_items);
+	
+/*	int general_work (	int noutput_items,
+						gr_vector_int &ninput_items,
+						gr_vector_const_void_star &input_items,
+						gr_vector_void_star &output_items);
+*/
+};
+
+#endif /* INCLUDED_gsm_burst_sink_c_H */
diff --git a/gsm-tvoid/src/lib/gsm_constants.h b/gsm-tvoid/src/lib/gsm_constants.h
index c404b57..c404b57 100755..100644
--- a/gsm-tvoid/src/lib/gsm_constants.h
+++ b/gsm-tvoid/src/lib/gsm_constants.h
diff --git a/gsm-tvoid/src/python/gsm_scan.py b/gsm-tvoid/src/python/gsm_scan.py
index 5d48ce5..6d25fd3 100755
--- a/gsm-tvoid/src/python/gsm_scan.py
+++ b/gsm-tvoid/src/python/gsm_scan.py
@@ -1,13 +1,15 @@
 #!/usr/bin/env python
 # TODO:
-#	* Adjust offset by PPM
-#	* Auto-tune offset (add option to enable)
 #	* Add status info to window (frequency, offset, etc)
 #	* Put direct frequency tuning back
 #	* Add rate-limited file reads (throttle?)
 #	* Make console only version
 #	* Reset burst_stats on retune
 #	* Add better option checking
+#	* Wideband (multi-channel) processing (usrp and/or file input)
+#	* Automatic beacon scan (quick scan RSSI, then check for BCCH)
+#	* AGC
+#	* Refactor, this is too messy
 
 import sys
 
@@ -26,6 +28,62 @@ from math import pi
 import wx
 import gsm
 
+
+class burst_callback(gr.feval_ll):
+	def __init__(self, fg):
+		gr.feval_ll.__init__(self)
+		self.fg = fg
+		self.offset_mean_num = 10		#number of FCCH offsets to average
+		self.offset_vals = []
+		
+	def eval(self, x):
+		#print "burst_callback: eval(",x,")\n";
+		try:
+			#TODO: rework so this will work on file input
+			if gsm.BURST_CB_SYNC_OFFSET == x:
+				#print "burst_callback: SYNC_OFFSET\n";
+				if self.fg.options.tuning.count("o"):
+					last_offset = self.fg.burst.last_freq_offset()
+					self.fg.offset -= last_offset
+					#print "burst_callback: SYNC_OFFSET:", last_offset, " ARFCN: ", self.fg.channel, "\n";
+					self.fg.set_channel(self.fg.channel)
+
+			elif gsm.BURST_CB_ADJ_OFFSET == x:
+				last_offset = self.fg.burst.last_freq_offset()
+
+				self.offset_vals.append(last_offset)
+				count =  len(self.offset_vals)
+				#print "burst_callback: ADJ_OFFSET:", last_offset, ", count=",count,"\n";
+
+				if count >= self.offset_mean_num:
+					sum = 0.0
+					while len(self.offset_vals):
+						sum += self.offset_vals.pop(0)
+
+					self.fg.mean_offset = sum / self.offset_mean_num
+
+					#print "burst_callback: mean offset:", self.fg.mean_offset, "\n";
+
+					#retune if greater than 100 Hz
+					if abs(self.fg.mean_offset) > 100.0:	
+						#print "burst_callback: mean offset adjust:", self.fg.mean_offset, "\n";
+						if self.fg.options.tuning.count("o"):	
+							#print "burst_callback: tuning.\n";
+							self.fg.offset -= self.fg.mean_offset
+							self.fg.set_channel(self.fg.channel)
+
+			elif gsm.BURST_CB_TUNE == x and self.fg.options.tuning.count("h"):
+				#print "burst_callback: BURST_CB_TUNE: ARFCN: ", self.fg.burst.next_arfcn, "\n";
+				if self.fg.options.tuning.count("h"):
+					#print "burst_callback: tuning.\n";
+					self.fg.set_channel(self.fg.burst.next_arfcn)
+
+			return 0
+
+		except Exception, e:
+			print "burst_callback: Exception: ", e
+
+
 def pick_subdevice(u):
 	if u.db[0][0].dbid() >= 0:
 		return (0, 0)
@@ -73,6 +131,9 @@ class app_flow_graph(stdgui.gui_flow_graph):
 	def __init__(self, frame, panel, vbox, argv):
 		stdgui.gui_flow_graph.__init__(self)
 
+		#testing
+		self.status_msg = "Started."
+		
 		self.frame = frame
 		self.panel = panel
 		
@@ -100,10 +161,15 @@ class app_flow_graph(stdgui.gui_flow_graph):
 							help="Sample clock offset frequency")
 		parser.add_option("-E", "--equalizer", type="string", default="none",
 							help="Type of equalizer to use.  none, fixed-dfe [default=%default]")
-		parser.add_option("-t", "--timing", type="string", default="cq",
+		parser.add_option("-t", "--timing", type="string", default="cn",
 							help="Type of timing techniques to use. [default=%default] \n" +
 							"(n)one, (c)orrelation track, (q)uarter bit, (f)ull04 ")
 
+		#tuning options
+		parser.add_option("-T", "--tuning", type="string", default="oh",
+							help="Type of tuning to perform. [default=%default] \n" +
+							"(n)one, (o)ffset adjustment, (h)opping ")
+		
 		#file options
 		parser.add_option("-I", "--inputfile", type="string", default=None,
 							help="Select a capture file to read")
@@ -115,10 +181,17 @@ class app_flow_graph(stdgui.gui_flow_graph):
 		#usrp options
 		parser.add_option("-R", "--rx-subdev-spec", type="subdev", default=None,
 							help="Select USRP Rx side A or B (default=first one with a daughterboard)")
+		parser.add_option("--fusb-block-size", type="int", default=0,
+							help="Set USRP blocksize")
+		parser.add_option("--fusb-nblocks", type="int", default=0,
+							help="Set USRP block buffers")
+		parser.add_option("--realtime",action="store_true", dest="realtime",
+							help="Use realtime scheduling.")
+
 		#FIXME: gain not working?
 		parser.add_option("-g", "--gain", type="eng_float", default=None,
 							help="Set gain in dB (default is midpoint)")
-		parser.add_option("-c", "--channel", type="int", default=None,
+		parser.add_option("-c", "--channel", type="int", default=1,
 							help="Tune to GSM ARFCN.  Overrides --freq")
 		parser.add_option("-r", "--region", type="string", default="u",
 							help="Frequency bands to use for channels.  (u)s or (e)urope [default=%default]")
@@ -134,6 +207,8 @@ class app_flow_graph(stdgui.gui_flow_graph):
 		self.region = options.region
 		self.channel = options.channel
 		self.offset = options.offset
+
+		self.mean_offset = 0.0		#this is relative averaged freq offset
 		
 		self.print_status = options.print_console.count('s')
 		
@@ -164,6 +239,31 @@ class app_flow_graph(stdgui.gui_flow_graph):
 		gsm_symb_rate = 1625000.0 / 6.0
 		sps = input_rate/gsm_symb_rate
 
+		# Attempt to enable realtime scheduling
+		if options.realtime:
+			r = gr.enable_realtime_scheduling()
+			if r == gr.RT_OK:
+				realtime = True
+				print "Realtime scheduling ENABLED"
+			else:
+				realtime = False
+				print "Realtime scheduling FAILED"
+		
+		#set resonable defaults if no user prefs set
+		if options.realtime:                        # be more aggressive
+			if options.fusb_block_size == 0:
+				options.fusb_block_size = gr.prefs().get_long('fusb', 'rt_block_size', 1024)
+			if options.fusb_nblocks == 0:
+				options.fusb_nblocks    = gr.prefs().get_long('fusb', 'rt_nblocks', 16)
+		else:
+			if options.fusb_block_size == 0:
+				options.fusb_block_size = gr.prefs().get_long('fusb', 'block_size', 4096)
+			if options.fusb_nblocks == 0:
+				options.fusb_nblocks    = gr.prefs().get_long('fusb', 'nblocks', 16)
+		
+		print "fusb_block_size =", options.fusb_block_size
+		print "fusb_nblocks    =", options.fusb_nblocks
+
 		# Build the flowgraph
 		# Setup our input source
 		if options.inputfile:
@@ -172,7 +272,8 @@ class app_flow_graph(stdgui.gui_flow_graph):
 			self.source = gr.file_source(gr.sizeof_gr_complex, options.inputfile, options.fileloop)
 		else:
 			self.using_usrp = True
-			self.u = usrp.source_c(decim_rate=options.decim)
+			self.u = usrp.source_c(decim_rate=options.decim,fusb_block_size=options.fusb_block_size,fusb_nblocks=options.fusb_nblocks)
+				
 			if options.rx_subdev_spec is None:
 				options.rx_subdev_spec = pick_subdevice(self.u)
 			self.u.set_mux(usrp.determine_rx_mux_value(self.u, options.rx_subdev_spec))
@@ -201,6 +302,7 @@ class app_flow_graph(stdgui.gui_flow_graph):
 		else:
 			offset = 0.0
 
+		#TODO: try a differnet filter for latency (and CPU)
 		filter_taps = gr.firdes.low_pass(1.0, input_rate, filter_cutoff, filter_t_width, gr.firdes.WIN_HAMMING)
 		self.filter = gr.freq_xlating_fir_filter_ccf(1, filter_taps, offset, input_rate)
 
@@ -217,9 +319,17 @@ class app_flow_graph(stdgui.gui_flow_graph):
 			if self.scopes.count("I"):
 				self.connect(self.u, self.input_fft_scope)
 
+		#create a tuner callback
+		self.burst_cb = burst_callback(self)
+		
 		# Setup flow based on decoder selection
 		if options.decoder.count("c"):
-			self.burst = gsm.burst_cf(input_rate)
+			#use the sink version if burst scope not selected
+			if self.scopes.count("b"):
+				self.burst = gsm.burst_cf(self.burst_cb,input_rate)
+			else:
+				self.burst = gsm.burst_sink_c(self.burst_cb,input_rate)
+			
 			self.connect(self.filter, self.burst)
 
 		elif options.decoder.count("f"):
@@ -236,7 +346,7 @@ class app_flow_graph(stdgui.gui_flow_graph):
 													gain_mu,
 													0.3)			#omega_relative_limit, 
 
-			self.burst = gsm.burst_ff()
+			self.burst = gsm.burst_ff(self.burst_cb)
 			self.connect(self.filter, self.demod, self.clocker, self.burst)
 
 			if self.scopes.count("d"):
@@ -247,31 +357,6 @@ class app_flow_graph(stdgui.gui_flow_graph):
 				self.clocked_scope = scopesink.scope_sink_f(self, panel, sample_rate=gsm_symb_rate,v_scale=1)
 				self.connect(self.clocker, self.clocked_scope)
 
-		elif options.decoder.count("F"):
-			#configure clock recovery
-			gain_mu = 0.01
-			gain_omega = .25 * gain_mu * gain_mu		# critically damped
-			self.clocker = gr.clock_recovery_mm_cc(	sps, 
-													gain_omega,
-													0.5,			#mu
-													gain_mu,
-													0.3)			#omega_relative_limit, 
-
-
-			# configure demodulator
-			self.demod = gr.quadrature_demod_cf(1);
-			
-			self.burst = gsm.burst_ff()
-			self.connect(self.filter, self.clocker, self.demod, self.burst)
-
-			if self.scopes.count("d"):
-				self.demod_scope = scopesink.scope_sink_f(self, panel, sample_rate=input_rate)
-				self.connect(self.demod, self.demod_scope)
-
-			if self.scopes.count("c"):
-				self.clocked_scope = scopesink.scope_sink_f(self, panel, sample_rate=gsm_symb_rate,v_scale=1)
-				self.connect(self.clocker, self.clocked_scope)
-
 
 		# setup decoder parameters
 		# equalizer
@@ -344,30 +429,26 @@ class app_flow_graph(stdgui.gui_flow_graph):
 			popts |= gsm.PRINT_GSM_DECODE
 		
 		#TODO: should warn if PRINT_GSM_DECODE is combined with other flags (will corrupt output for gsmdecode)
-		
 		self.burst.d_print_options = popts	
 		
-		##########################
-		#set burst tuning callback
-		#self.tuner = gsm_tuner()
-		#self.burst.set_tuner_callback(self.tuner)
-		
-		# connect the primary path after source
-		self.v2s = gr.vector_to_stream(gr.sizeof_float,142)		#burst output is 142 (USEFUL_BITS)
-		self.connect(self.burst, self.v2s)
 
 		# create and connect the scopes that apply to all decoders
 		if self.scopes.count("F"):
 			self.filter_fft_scope = fftsink.fft_sink_c (self, panel, fft_size=1024, sample_rate=input_rate)
 			self.connect(self.filter, self.filter_fft_scope)
 
+		# connect the burst output
+		if self.scopes.count("b") or options.outputfile:
+			self.v2s = gr.vector_to_stream(gr.sizeof_float,142)		#burst output is 142 (USEFUL_BITS)
+			self.connect(self.burst, self.v2s)
+#		else:
+#			self.burst_sink = gr.null_sink(gr.sizeof_float)
+#			self.connect(self.v2s, self.burst_sink)
+
 		#Connect output sinks
 		if self.scopes.count("b"):
 			self.burst_scope = scopesink.scope_sink_f(self, panel, sample_rate=gsm_symb_rate,v_scale=1)
 			self.connect(self.v2s, self.burst_scope)
-		elif not options.outputfile:
-			self.burst_sink = gr.null_sink(gr.sizeof_float)
-			self.connect(self.v2s, self.burst_sink)
 							
 		# setup & connect output file
 		if options.outputfile:
@@ -383,6 +464,9 @@ class app_flow_graph(stdgui.gui_flow_graph):
 		self.t1.Start(5000,0)
 		self.frame.Bind(wx.EVT_TIMER, self.on_tick)
 
+		#bind the idle routing for message_queue processing	
+		self.frame.Bind(wx.EVT_IDLE, self.on_idle)
+
 
 	def _set_status_msg(self, msg):
 		self.frame.GetStatusBar().SetStatusText(msg, 0)
@@ -428,22 +512,28 @@ class app_flow_graph(stdgui.gui_flow_graph):
 												callback=self.set_channel)
 
 			vbox.Add(hbox, 0, wx.EXPAND)
-
+		
 
 	def set_freq(self, freq):
-
+		#TODO: for wideband processing, determine if the desired freq is within our current sample range.
+		#		If so, use the frequency translator to tune.  Tune the USRP otherwise.
+		#		Maybe have a flag to force tuning the USRP?
+		
 		if not self.using_usrp:
-			return False
+			#if reading from file just adjust for offset in the freq translator
+			print "Setting filter center freq to offset: ", self.offset, "\n"
+			self.filter.set_center_freq(self.offset) 
+			return True
 	
 		freq = freq - self.offset
 
 		r = self.u.tune(0, self.subdev, freq)
 
 		if r:
-			self._set_status_msg('%f' % (freq/1e6))
+			self.status_msg = '%f' % (freq/1e6)
 			return True
 		else:
-			self._set_status_msg("Failed to set frequency (%f)" % (freq/1e6))
+			self.status_msg = "Failed to set frequency (%f)" % (freq/1e6)
 			return False
 
 	def set_gain(self, gain):
@@ -455,23 +545,24 @@ class app_flow_graph(stdgui.gui_flow_graph):
 
 	def set_channel(self, chan):
 
-		if not self.using_usrp:
-			return False
+		self.chan = chan
 		
 		freq = get_freq_from_arfcn(chan,self.region)
 
 		if freq:
 			self.set_freq(freq)
 		else:
-			self._set_status_msg("Invalid Channel")
+			self.status_msg = "Invalid Channel"
 
 	def print_stats(self):
+
 		n_total = self.burst.d_total_count
 		n_unknown = self.burst.d_unknown_count
 		n_known = n_total - n_unknown
 		
 		print "======== STATS ========="
-		print 'freq_offset:    ',self.burst.mean_freq_offset()
+		print 'freq_offset:    ',self.offset
+		print 'mean_offset:    ',self.mean_offset
 		print 'sync_loss_count:',self.burst.d_sync_loss_count
 		print 'total_bursts:   ',n_total
 		print 'fcch_count:     ',self.burst.d_fcch_count
@@ -491,7 +582,13 @@ class app_flow_graph(stdgui.gui_flow_graph):
 			
 		if self.print_status:
 			self.print_stats()
-			
+
+	def on_idle(self, event):
+		#We can't update this while in the tune functions since they can be invoked by callbaks and the GUI croaks...
+		#FIXME: This is icky.
+		self._set_status_msg(self.status_msg)
+		#print "Idle.\n";
+
 def main ():
 	app = stdgui.stdapp(app_flow_graph, "GSM Scanner", nstatus=1)
 	app.MainLoop()