Merge pull request #1741 from simonduq/pr/tsch-adaptive-control-traffic

TSCH adaptive control traffic

core/net/mac/tsch/tsch-adaptive-timesync.c

@@ -38,8 +38,10 @@
  *
  */
 
-#include "tsch-adaptive-timesync.h"
-#include "tsch-log.h"
+#include "net/mac/tsch/tsch.h"
+#include "net/mac/tsch/tsch-conf.h"
+#include "net/mac/tsch/tsch-adaptive-timesync.h"
+#include "net/mac/tsch/tsch-log.h"
 #include <stdio.h>
 
 #if TSCH_ADAPTIVE_TIMESYNC
@@ -72,6 +74,10 @@ timesync_entry_add(int32_t val, uint32_t time_delta)
   buffer[pos] = val;
   if(timesync_entry_count < NUM_TIMESYNC_ENTRIES) {
     timesync_entry_count++;
+  } else {
+    /* We now have accurate drift compensation.
+     * Increase keep-alive timeout. */
+    tsch_set_ka_timeout(TSCH_MAX_KEEPALIVE_TIMEOUT);
   }
   pos = (pos + 1) % NUM_TIMESYNC_ENTRIES;
 

core/net/mac/tsch/tsch-conf.h

@@ -174,7 +174,7 @@
 #ifdef TSCH_CONF_ADAPTIVE_TIMESYNC
 #define TSCH_ADAPTIVE_TIMESYNC TSCH_CONF_ADAPTIVE_TIMESYNC
 #else
-#define TSCH_ADAPTIVE_TIMESYNC 0
+#define TSCH_ADAPTIVE_TIMESYNC 1
 #endif
 
 /* HW frame filtering enabled */

core/net/mac/tsch/tsch-rpl.c

@@ -85,7 +85,7 @@ tsch_rpl_callback_new_dio_interval(uint8_t dio_interval)
       tsch_set_coordinator(1);
     }
     /* Set EB period */
-    tsch_set_eb_period(TSCH_EB_PERIOD);
+    tsch_set_eb_period((CLOCK_SECOND * 1UL << dag->instance->dio_intcurrent) / 1000);
     /* Set join priority based on RPL rank */
     tsch_set_join_priority(DAG_RANK(dag->rank, dag->instance) - 1);
   } else {

core/net/mac/tsch/tsch.c

@@ -139,6 +139,8 @@ uint8_t tsch_join_priority;
 static uint8_t tsch_packet_seqno = 0;
 /* Current period for EB output */
 static clock_time_t tsch_current_eb_period;
+/* Current period for keepalive output */
+static clock_time_t tsch_current_ka_timeout;
 
 /* timer for sending keepalive messages */
 static struct ctimer keepalive_timer;
@@ -175,9 +177,15 @@ tsch_set_join_priority(uint8_t jp)
 }
 /*---------------------------------------------------------------------------*/
 void
+tsch_set_ka_timeout(uint32_t timeout)
+{
+  tsch_current_ka_timeout = timeout;
+}
+/*---------------------------------------------------------------------------*/
+void
 tsch_set_eb_period(uint32_t period)
 {
-  tsch_current_eb_period = period;
+  tsch_current_eb_period = MIN(period, TSCH_MAX_EB_PERIOD);
 }
 /*---------------------------------------------------------------------------*/
 static void
@@ -244,10 +252,10 @@ keepalive_send()
 void
 tsch_schedule_keepalive()
 {
-  /* Pick a delay in the range [TSCH_KEEPALIVE_TIMEOUT*0.9, TSCH_KEEPALIVE_TIMEOUT[ */
-  if(!tsch_is_coordinator && tsch_is_associated) {
-    unsigned long delay = (TSCH_KEEPALIVE_TIMEOUT - TSCH_KEEPALIVE_TIMEOUT / 10)
-      + random_rand() % (TSCH_KEEPALIVE_TIMEOUT / 10);
+  /* Pick a delay in the range [tsch_current_ka_timeout*0.9, tsch_current_ka_timeout[ */
+  if(!tsch_is_coordinator && tsch_is_associated && tsch_current_ka_timeout > 0) {
+    unsigned long delay = (tsch_current_ka_timeout - tsch_current_ka_timeout / 10)
+      + random_rand() % (tsch_current_ka_timeout / 10);
     ctimer_set(&keepalive_timer, delay, keepalive_send, NULL);
   }
 }

core/net/mac/tsch/tsch.h

@@ -49,18 +49,33 @@
 #define TSCH_KEEPALIVE_TIMEOUT (12 * CLOCK_SECOND)
 #endif
 
+/* With TSCH_ADAPTIVE_TIMESYNC enabled: keep-alive timeout used after reaching
+ * accurate drift compensation. */
+#ifdef TSCH_CONF_MAX_KEEPALIVE_TIMEOUT
+#define TSCH_MAX_KEEPALIVE_TIMEOUT TSCH_CONF_MAX_KEEPALIVE_TIMEOUT
+#else
+#define TSCH_MAX_KEEPALIVE_TIMEOUT (60 * CLOCK_SECOND)
+#endif
+
 /* Max time without synchronization before leaving the PAN */
 #ifdef TSCH_CONF_DESYNC_THRESHOLD
 #define TSCH_DESYNC_THRESHOLD TSCH_CONF_DESYNC_THRESHOLD
 #else
-#define TSCH_DESYNC_THRESHOLD (4 * TSCH_KEEPALIVE_TIMEOUT)
+#define TSCH_DESYNC_THRESHOLD (2 * TSCH_MAX_KEEPALIVE_TIMEOUT)
 #endif
 
 /* Period between two consecutive EBs */
 #ifdef TSCH_CONF_EB_PERIOD
 #define TSCH_EB_PERIOD TSCH_CONF_EB_PERIOD
 #else
-#define TSCH_EB_PERIOD (4 * CLOCK_SECOND)
+#define TSCH_EB_PERIOD (16 * CLOCK_SECOND)
+#endif
+
+/* Max Period between two consecutive EBs */
+#ifdef TSCH_CONF_MAX_EB_PERIOD
+#define TSCH_MAX_EB_PERIOD TSCH_CONF_MAX_EB_PERIOD
+#else
+#define TSCH_MAX_EB_PERIOD (50 * CLOCK_SECOND)
 #endif
 
 /* Max acceptable join priority */
@@ -157,8 +172,10 @@ extern const struct mac_driver tschmac_driver;
 
 /* The the TSCH join priority */
 void tsch_set_join_priority(uint8_t jp);
-/* The the period at which EBs are sent */
+/* The period at which EBs are sent */
 void tsch_set_eb_period(uint32_t period);
+/* The keep-alive timeout */
+void tsch_set_ka_timeout(uint32_t timeout);
 /* Set the node as PAN coordinator */
 void tsch_set_coordinator(int enable);
 /* Set the pan as secured or not */