Merge pull request #1708 from atiselsts/tsch_enhancements

TSCH enhancements

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

@@ -86,12 +86,16 @@ timesync_entry_add(int32_t val, uint32_t time_delta)
 static void
 timesync_learn_drift_ticks(uint32_t time_delta_asn, int32_t drift_ticks)
 {
-  /* should fit in 32-bit unsigned integer */
+  /* should fit in a 32-bit integer */
-  uint32_t time_delta_ticks = time_delta_asn * tsch_timing[tsch_ts_timeslot_length];
+  int32_t time_delta_ticks = time_delta_asn * tsch_timing[tsch_ts_timeslot_length];
   int32_t real_drift_ticks = drift_ticks + compensated_ticks;
   int32_t last_drift_ppm = (int32_t)((int64_t)real_drift_ticks * TSCH_DRIFT_UNIT / time_delta_ticks);
 
   drift_ppm = timesync_entry_add(last_drift_ppm, time_delta_ticks);
+
+  TSCH_LOG_ADD(tsch_log_message,
+      snprintf(log->message, sizeof(log->message),
+          "drift %ld", drift_ppm / 256));
 }
 /*---------------------------------------------------------------------------*/
 /* Either reset or update the neighbor's drift */

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

@@ -53,6 +53,8 @@
 #define TSCH_HOPPING_SEQUENCE_4_16 (uint8_t[]){ 20, 26, 25, 26, 15, 15, 25, 20, 26, 15, 26, 25, 20, 15, 20, 25 }
 /* 4 channels, sequence length 4 */
 #define TSCH_HOPPING_SEQUENCE_4_4 (uint8_t[]){ 15, 25, 26, 20 }
+/* 2 channels, sequence length 2 */
+#define TSCH_HOPPING_SEQUENCE_2_2 (uint8_t[]){ 20, 25 }
 /* 1 channel, sequence length 1 */
 #define TSCH_HOPPING_SEQUENCE_1_1 (uint8_t[]){ 20 }
 
@@ -120,7 +122,7 @@
 #define TSCH_DEFAULT_TS_TIMESLOT_LENGTH    10000
 
 #elif TSCH_CONF_DEFAULT_TIMESLOT_LENGTH == 15000
-/* Default timeslot timing for platfroms requiring 15ms slots */
+/* Default timeslot timing for platforms requiring 15ms slots */
 
 #define TSCH_DEFAULT_TS_CCA_OFFSET         1800
 #define TSCH_DEFAULT_TS_CCA                128
@@ -182,4 +184,18 @@
 #define TSCH_HW_FRAME_FILTERING 1
 #endif /* TSCH_CONF_HW_FRAME_FILTERING */
 
+/* Keep radio always on within TSCH timeslot (1) or turn it off between packet and ACK? (0) */
+#ifdef TSCH_CONF_RADIO_ON_DURING_TIMESLOT
+#define TSCH_RADIO_ON_DURING_TIMESLOT TSCH_CONF_RADIO_ON_DURING_TIMESLOT
+#else
+#define TSCH_RADIO_ON_DURING_TIMESLOT 0
+#endif
+
+/* How long to scan each channel in the scanning phase */
+#ifdef TSCH_CONF_CHANNEL_SCAN_DURATION
+#define TSCH_CHANNEL_SCAN_DURATION TSCH_CONF_CHANNEL_SCAN_DURATION
+#else
+#define TSCH_CHANNEL_SCAN_DURATION CLOCK_SECOND
+#endif
+
 #endif /* __TSCH_CONF_H__ */

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

@@ -39,6 +39,7 @@
 #include "lib/ringbufindex.h"
 #include "net/linkaddr.h"
 #include "net/mac/tsch/tsch-schedule.h"
+#include "net/mac/mac.h"
 
 /******** Configuration *******/
 

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

@@ -73,7 +73,7 @@ tsch_rpl_callback_leaving_network(void)
 }
 /*---------------------------------------------------------------------------*/
 /* Set TSCH EB period based on current RPL DIO period.
- * To use, set #define RPL_CALLBACK_PARENT_SWITCH tsch_rpl_callback_new_dio_interval */
+ * To use, set #define RPL_CALLBACK_NEW_DIO_INTERVAL tsch_rpl_callback_new_dio_interval */
 void
 tsch_rpl_callback_new_dio_interval(uint8_t dio_interval)
 {

core/net/mac/tsch/tsch-slot-operation.c

@@ -36,6 +36,7 @@
  * \author
  *         Simon Duquennoy <simonduq@sics.se>
  *         Beshr Al Nahas <beshr@sics.se>
+ *         Atis Elsts <atis.elsts@bristol.ac.uk>
  *
  */
 
@@ -109,6 +110,18 @@
 #define RTIMER_GUARD 2u
 #endif
 
+enum tsch_radio_state_on_cmd {
+  TSCH_RADIO_CMD_ON_START_OF_TIMESLOT,
+  TSCH_RADIO_CMD_ON_WITHIN_TIMESLOT,
+  TSCH_RADIO_CMD_ON_FORCE,
+};
+
+enum tsch_radio_state_off_cmd {
+  TSCH_RADIO_CMD_OFF_END_OF_TIMESLOT,
+  TSCH_RADIO_CMD_OFF_WITHIN_TIMESLOT,
+  TSCH_RADIO_CMD_OFF_FORCE,
+};
+
 /* A ringbuf storing outgoing packets after they were dequeued.
  * Will be processed layer by tsch_tx_process_pending */
 struct ringbufindex dequeued_ringbuf;
@@ -370,6 +383,68 @@ update_neighbor_state(struct tsch_neighbor *n, struct tsch_packet *p,
   return in_queue;
 }
 /*---------------------------------------------------------------------------*/
+/**
+ * This function turns on the radio. Its semantics is dependent on
+ * the value of TSCH_RADIO_ON_DURING_TIMESLOT constant:
+ * - if enabled, the radio is turned on at the start of the slot
+ * - if disabled, the radio is turned on within the slot,
+ *   directly before the packet Rx guard time and ACK Rx guard time.
+ */
+static void
+tsch_radio_on(enum tsch_radio_state_on_cmd command)
+{
+  int do_it = 0;
+  switch(command) {
+  case TSCH_RADIO_CMD_ON_START_OF_TIMESLOT:
+    if(TSCH_RADIO_ON_DURING_TIMESLOT) {
+      do_it = 1;
+    }
+    break;
+  case TSCH_RADIO_CMD_ON_WITHIN_TIMESLOT:
+    if(!TSCH_RADIO_ON_DURING_TIMESLOT) {
+      do_it = 1;
+    }
+    break;
+  case TSCH_RADIO_CMD_ON_FORCE:
+    do_it = 1;
+    break;
+  }
+  if(do_it) {
+    NETSTACK_RADIO.on();
+  }
+}
+/*---------------------------------------------------------------------------*/
+/**
+ * This function turns off the radio. In the same way as for tsch_radio_on(),
+ * it depends on the value of TSCH_RADIO_ON_DURING_TIMESLOT constant:
+ * - if enabled, the radio is turned off at the end of the slot
+ * - if disabled, the radio is turned off within the slot,
+ *   directly after Tx'ing or Rx'ing a packet or Tx'ing an ACK.
+ */
+static void
+tsch_radio_off(enum tsch_radio_state_off_cmd command)
+{
+  int do_it = 0;
+  switch(command) {
+  case TSCH_RADIO_CMD_OFF_END_OF_TIMESLOT:
+    if(TSCH_RADIO_ON_DURING_TIMESLOT) {
+      do_it = 1;
+    }
+    break;
+  case TSCH_RADIO_CMD_OFF_WITHIN_TIMESLOT:
+    if(!TSCH_RADIO_ON_DURING_TIMESLOT) {
+      do_it = 1;
+    }
+    break;
+  case TSCH_RADIO_CMD_OFF_FORCE:
+    do_it = 1;
+    break;
+  }
+  if(do_it) {
+    NETSTACK_RADIO.off();
+  }
+}
+/*---------------------------------------------------------------------------*/
 static
 PT_THREAD(tsch_tx_slot(struct pt *pt, struct rtimer *t))
 {
@@ -456,7 +531,7 @@ PT_THREAD(tsch_tx_slot(struct pt *pt, struct rtimer *t))
         /* delay before CCA */
         TSCH_SCHEDULE_AND_YIELD(pt, t, current_slot_start, TS_CCA_OFFSET, "cca");
         TSCH_DEBUG_TX_EVENT();
-        NETSTACK_RADIO.on();
+        tsch_radio_on(TSCH_RADIO_CMD_ON_WITHIN_TIMESLOT);
         /* CCA */
         BUSYWAIT_UNTIL_ABS(!(cca_status |= NETSTACK_RADIO.channel_clear()),
                            current_slot_start, TS_CCA_OFFSET + TS_CCA);
@@ -480,7 +555,7 @@ PT_THREAD(tsch_tx_slot(struct pt *pt, struct rtimer *t))
           /* limit tx_time to its max value */
           tx_duration = MIN(tx_duration, tsch_timing[tsch_ts_max_tx]);
           /* turn tadio off -- will turn on again to wait for ACK if needed */
-          NETSTACK_RADIO.off();
+          tsch_radio_off(TSCH_RADIO_CMD_OFF_WITHIN_TIMESLOT);
 
           if(mac_tx_status == RADIO_TX_OK) {
             if(!is_broadcast) {
@@ -488,12 +563,12 @@ PT_THREAD(tsch_tx_slot(struct pt *pt, struct rtimer *t))
               int ack_len;
               rtimer_clock_t ack_start_time;
               int is_time_source;
-              radio_value_t radio_rx_mode;
               struct ieee802154_ies ack_ies;
               uint8_t ack_hdrlen;
               frame802154_t frame;
 
 #if TSCH_HW_FRAME_FILTERING
+              radio_value_t radio_rx_mode;
               /* Entering promiscuous mode so that the radio accepts the enhanced ACK */
               NETSTACK_RADIO.get_value(RADIO_PARAM_RX_MODE, &radio_rx_mode);
               NETSTACK_RADIO.set_value(RADIO_PARAM_RX_MODE, radio_rx_mode & (~RADIO_RX_MODE_ADDRESS_FILTER));
@@ -502,7 +577,7 @@ PT_THREAD(tsch_tx_slot(struct pt *pt, struct rtimer *t))
               TSCH_SCHEDULE_AND_YIELD(pt, t, current_slot_start,
                   tsch_timing[tsch_ts_tx_offset] + tx_duration + tsch_timing[tsch_ts_rx_ack_delay] - RADIO_DELAY_BEFORE_RX, "TxBeforeAck");
               TSCH_DEBUG_TX_EVENT();
-              NETSTACK_RADIO.on();
+              tsch_radio_on(TSCH_RADIO_CMD_ON_WITHIN_TIMESLOT);
               /* Wait for ACK to come */
               BUSYWAIT_UNTIL_ABS(NETSTACK_RADIO.receiving_packet(),
                   tx_start_time, tx_duration + tsch_timing[tsch_ts_rx_ack_delay] + tsch_timing[tsch_ts_ack_wait]);
@@ -514,7 +589,7 @@ PT_THREAD(tsch_tx_slot(struct pt *pt, struct rtimer *t))
               BUSYWAIT_UNTIL_ABS(!NETSTACK_RADIO.receiving_packet(),
                                  ack_start_time, tsch_timing[tsch_ts_max_ack]);
               TSCH_DEBUG_TX_EVENT();
-              NETSTACK_RADIO.off();
+              tsch_radio_off(TSCH_RADIO_CMD_OFF_WITHIN_TIMESLOT);
 
 #if TSCH_HW_FRAME_FILTERING
               /* Leaving promiscuous mode */
@@ -588,6 +663,8 @@ PT_THREAD(tsch_tx_slot(struct pt *pt, struct rtimer *t))
       }
     }
 
+    tsch_radio_off(TSCH_RADIO_CMD_OFF_END_OF_TIMESLOT);
+
     current_packet->transmissions++;
     current_packet->ret = mac_tx_status;
 
@@ -671,32 +748,26 @@ PT_THREAD(tsch_rx_slot(struct pt *pt, struct rtimer *t))
     TSCH_DEBUG_RX_EVENT();
 
     /* Start radio for at least guard time */
-    NETSTACK_RADIO.on();
+    tsch_radio_on(TSCH_RADIO_CMD_ON_WITHIN_TIMESLOT);
-    packet_seen = NETSTACK_RADIO.receiving_packet();
+    packet_seen = NETSTACK_RADIO.receiving_packet() || NETSTACK_RADIO.pending_packet();
     if(!packet_seen) {
       /* Check if receiving within guard time */
       BUSYWAIT_UNTIL_ABS((packet_seen = NETSTACK_RADIO.receiving_packet()),
           current_slot_start, tsch_timing[tsch_ts_rx_offset] + tsch_timing[tsch_ts_rx_wait]);
     }
-    if(packet_seen) {
+    if(!packet_seen) {
+      /* no packets on air */
+      tsch_radio_off(TSCH_RADIO_CMD_OFF_FORCE);
+    } else {
       TSCH_DEBUG_RX_EVENT();
       /* Save packet timestamp */
       rx_start_time = RTIMER_NOW() - RADIO_DELAY_BEFORE_DETECT;
-    }
+
-    if(!NETSTACK_RADIO.receiving_packet() && !NETSTACK_RADIO.pending_packet()) {
-      NETSTACK_RADIO.off();
-      /* no packets on air */
-    } else {
       /* Wait until packet is received, turn radio off */
       BUSYWAIT_UNTIL_ABS(!NETSTACK_RADIO.receiving_packet(),
           current_slot_start, tsch_timing[tsch_ts_rx_offset] + tsch_timing[tsch_ts_rx_wait] + tsch_timing[tsch_ts_max_tx]);
       TSCH_DEBUG_RX_EVENT();
-      NETSTACK_RADIO.off();
+      tsch_radio_off(TSCH_RADIO_CMD_OFF_WITHIN_TIMESLOT);
-
-#if TSCH_RESYNC_WITH_SFD_TIMESTAMPS
-      /* At the end of the reception, get an more accurate estimate of SFD arrival time */
-      NETSTACK_RADIO.get_object(RADIO_PARAM_LAST_PACKET_TIMESTAMP, &rx_start_time, sizeof(rtimer_clock_t));
-#endif
 
       if(NETSTACK_RADIO.pending_packet()) {
         static int frame_valid;
@@ -704,9 +775,9 @@ PT_THREAD(tsch_rx_slot(struct pt *pt, struct rtimer *t))
         static frame802154_t frame;
         radio_value_t radio_last_rssi;
 
-        NETSTACK_RADIO.get_value(RADIO_PARAM_LAST_RSSI, &radio_last_rssi);
         /* Read packet */
         current_input->len = NETSTACK_RADIO.read((void *)current_input->payload, TSCH_PACKET_MAX_LEN);
+        NETSTACK_RADIO.get_value(RADIO_PARAM_LAST_RSSI, &radio_last_rssi);
         current_input->rx_asn = current_asn;
         current_input->rssi = (signed)radio_last_rssi;
         header_len = frame802154_parse((uint8_t *)current_input->payload, current_input->len, &frame);
@@ -714,6 +785,11 @@ PT_THREAD(tsch_rx_slot(struct pt *pt, struct rtimer *t))
           frame802154_check_dest_panid(&frame) &&
           frame802154_extract_linkaddr(&frame, &source_address, &destination_address);
 
+#if TSCH_RESYNC_WITH_SFD_TIMESTAMPS
+        /* At the end of the reception, get an more accurate estimate of SFD arrival time */
+        NETSTACK_RADIO.get_object(RADIO_PARAM_LAST_PACKET_TIMESTAMP, &rx_start_time, sizeof(rtimer_clock_t));
+#endif
+
         packet_duration = TSCH_PACKET_DURATION(current_input->len);
 
 #if LLSEC802154_ENABLED
@@ -745,7 +821,7 @@ PT_THREAD(tsch_rx_slot(struct pt *pt, struct rtimer *t))
 
 #if TSCH_TIMESYNC_REMOVE_JITTER
             /* remove jitter due to measurement errors */
-            if(abs(estimated_drift) <= TSCH_TIMESYNC_MEASUREMENT_ERROR) {
+            if(ABS(estimated_drift) <= TSCH_TIMESYNC_MEASUREMENT_ERROR) {
               estimated_drift = 0;
             } else if(estimated_drift > 0) {
               estimated_drift -= TSCH_TIMESYNC_MEASUREMENT_ERROR;
@@ -784,7 +860,7 @@ PT_THREAD(tsch_rx_slot(struct pt *pt, struct rtimer *t))
                   packet_duration + tsch_timing[tsch_ts_tx_ack_delay] - RADIO_DELAY_BEFORE_TX, "RxBeforeAck");
               TSCH_DEBUG_RX_EVENT();
               NETSTACK_RADIO.transmit(ack_len);
-              NETSTACK_RADIO.off();
+              tsch_radio_off(TSCH_RADIO_CMD_OFF_WITHIN_TIMESLOT);
             }
 
             /* If the sender is a time source, proceed to clock drift compensation */
@@ -820,6 +896,8 @@ PT_THREAD(tsch_rx_slot(struct pt *pt, struct rtimer *t))
           process_poll(&tsch_pending_events_process);
         }
       }
+
+      tsch_radio_off(TSCH_RADIO_CMD_OFF_END_OF_TIMESLOT);
     }
 
     if(input_queue_drop != 0) {
@@ -860,8 +938,12 @@ PT_THREAD(tsch_slot_operation(struct rtimer *t, void *ptr))
 
     } else {
       uint8_t current_channel;
+      int is_active_slot;
       TSCH_DEBUG_SLOT_START();
       tsch_in_slot_operation = 1;
+      /* Reset drift correction */
+      drift_correction = 0;
+      is_drift_correction_used = 0;
       /* Get a packet ready to be sent */
       current_packet = get_packet_and_neighbor_for_link(current_link, &current_neighbor);
       /* There is no packet to send, and this link does not have Rx flag. Instead of doing
@@ -870,12 +952,13 @@ PT_THREAD(tsch_slot_operation(struct rtimer *t, void *ptr))
         current_link = backup_link;
         current_packet = get_packet_and_neighbor_for_link(current_link, &current_neighbor);
       }
+      is_active_slot = current_packet != NULL || (current_link->link_options & LINK_OPTION_RX);
+      if(is_active_slot) {
         /* Hop channel */
         current_channel = tsch_calculate_channel(&current_asn, current_link->channel_offset);
         NETSTACK_RADIO.set_value(RADIO_PARAM_CHANNEL, current_channel);
-      /* Reset drift correction */
+        /* Turn the radio on already here if configured so; necessary for radios with slow startup */
-      drift_correction = 0;
+        tsch_radio_on(TSCH_RADIO_CMD_ON_START_OF_TIMESLOT);
-      is_drift_correction_used = 0;
         /* Decide whether it is a TX/RX/IDLE or OFF slot */
         /* Actual slot operation */
         if(current_packet != NULL) {
@@ -886,11 +969,12 @@ PT_THREAD(tsch_slot_operation(struct rtimer *t, void *ptr))
            **/
           static struct pt slot_tx_pt;
           PT_SPAWN(&slot_operation_pt, &slot_tx_pt, tsch_tx_slot(&slot_tx_pt, t));
-      } else if((current_link->link_options & LINK_OPTION_RX)) {
+        } else {
           /* Listen */
           static struct pt slot_rx_pt;
           PT_SPAWN(&slot_operation_pt, &slot_rx_pt, tsch_rx_slot(&slot_rx_pt, t));
         }
+      }
       TSCH_DEBUG_SLOT_END();
     }
 

core/net/mac/tsch/tsch.c

@@ -609,24 +609,25 @@ PT_THREAD(tsch_scan(struct pt *pt))
 
   static struct input_packet input_eb;
   static struct etimer scan_timer;
+  /* Time when we started scanning on current_channel */
+  static clock_time_t current_channel_since;
 
   ASN_INIT(current_asn, 0, 0);
 
   etimer_set(&scan_timer, CLOCK_SECOND / TSCH_ASSOCIATION_POLL_FREQUENCY);
+  current_channel_since = clock_time();
 
   while(!tsch_is_associated && !tsch_is_coordinator) {
     /* Hop to any channel offset */
-    static int current_channel = 0;
+    static uint8_t current_channel = 0;
-    /* Time when we started scanning on current_channel */
-    static clock_time_t current_channel_since = 0;
 
     /* We are not coordinator, try to associate */
     rtimer_clock_t t0;
     int is_packet_pending = 0;
-    clock_time_t now_seconds = clock_seconds();
+    clock_time_t now_time = clock_time();
 
     /* Switch to a (new) channel for scanning */
-    if(current_channel == 0 || now_seconds != current_channel_since) {
+    if(current_channel == 0 || now_time - current_channel_since > TSCH_CHANNEL_SCAN_DURATION) {
       /* Pick a channel at random in TSCH_JOIN_HOPPING_SEQUENCE */
       uint8_t scan_channel = TSCH_JOIN_HOPPING_SEQUENCE[
           random_rand() % sizeof(TSCH_JOIN_HOPPING_SEQUENCE)];
@@ -635,7 +636,7 @@ PT_THREAD(tsch_scan(struct pt *pt))
         current_channel = scan_channel;
         PRINTF("TSCH: scanning on channel %u\n", scan_channel);
       }
-      current_channel_since = now_seconds;
+      current_channel_since = now_time;
     }
 
     /* Turn radio on and wait for EB */
@@ -649,12 +650,12 @@ PT_THREAD(tsch_scan(struct pt *pt))
     }
 
     if(is_packet_pending) {
-      /* Save packet timestamp */
-      NETSTACK_RADIO.get_object(RADIO_PARAM_LAST_PACKET_TIMESTAMP, &t0, sizeof(rtimer_clock_t));
-
       /* Read packet */
       input_eb.len = NETSTACK_RADIO.read(input_eb.payload, TSCH_PACKET_MAX_LEN);
 
+      /* Save packet timestamp */
+      NETSTACK_RADIO.get_object(RADIO_PARAM_LAST_PACKET_TIMESTAMP, &t0, sizeof(rtimer_clock_t));
+
       /* Parse EB and attempt to associate */
       PRINTF("TSCH: association: received packet (%u bytes) on channel %u\n", input_eb.len, current_channel);