From a5a2a0510181de24f269e25bffe7f2c376f6b2fd Mon Sep 17 00:00:00 2001
From: Simon Duquennoy <simon.duquennoy@ri.se>
Date: Mon, 26 Mar 2018 11:15:17 -0700
Subject: [PATCH 01/10] TSCH: implement burst mode

---
 os/net/mac/tsch/tsch-const.h          |  1 +
 os/net/mac/tsch/tsch-packet.c         | 14 ++++++++
 os/net/mac/tsch/tsch-packet.h         |  4 +++
 os/net/mac/tsch/tsch-slot-operation.c | 49 ++++++++++++++++++++++++---
 os/net/mac/tsch/tsch-slot-operation.h |  2 ++
 5 files changed, 65 insertions(+), 5 deletions(-)

diff --git a/os/net/mac/tsch/tsch-const.h b/os/net/mac/tsch/tsch-const.h
index 81ca7ffa8..51e7d0625 100644
--- a/os/net/mac/tsch/tsch-const.h
+++ b/os/net/mac/tsch/tsch-const.h
@@ -53,6 +53,7 @@
 #define LINK_OPTION_RX              2
 #define LINK_OPTION_SHARED          4
 #define LINK_OPTION_TIME_KEEPING    8
+#define LINK_OPTION_BURST          16
 
 /* Default IEEE 802.15.4e hopping sequences, obtained from https://gist.github.com/twatteyne/2e22ee3c1a802b685695 */
 /* 16 channels, sequence length 16 */
diff --git a/os/net/mac/tsch/tsch-packet.c b/os/net/mac/tsch/tsch-packet.c
index 64f03b588..5f6cb6b54 100644
--- a/os/net/mac/tsch/tsch-packet.c
+++ b/os/net/mac/tsch/tsch-packet.c
@@ -459,4 +459,18 @@ tsch_packet_parse_eb(const uint8_t *buf, int buf_size,
   return curr_len;
 }
 /*---------------------------------------------------------------------------*/
+/* Set frame pending bit in a packet (whose header was already build) */
+void
+tsch_packet_set_frame_pending(uint8_t *buf, int buf_size)
+{
+  buf[0] |= (1 << 4);
+}
+/*---------------------------------------------------------------------------*/
+/* Get frame pending bit from a packet */
+int
+tsch_packet_get_frame_pending(uint8_t *buf, int buf_size)
+{
+  return (buf[0] >> 4) & 1;
+}
+/*---------------------------------------------------------------------------*/
 /** @} */
diff --git a/os/net/mac/tsch/tsch-packet.h b/os/net/mac/tsch/tsch-packet.h
index 6b05d6653..a7426ebac 100644
--- a/os/net/mac/tsch/tsch-packet.h
+++ b/os/net/mac/tsch/tsch-packet.h
@@ -101,6 +101,10 @@ int tsch_packet_update_eb(uint8_t *buf, int buf_size, uint8_t tsch_sync_ie_offse
 int tsch_packet_parse_eb(const uint8_t *buf, int buf_size,
     frame802154_t *frame, struct ieee802154_ies *ies,
     uint8_t *hdrlen, int frame_without_mic);
+/* Set frame pending bit in a packet (whose header was already build) */
+void tsch_packet_set_frame_pending(uint8_t *buf, int buf_size);
+/* Get frame pending bit from a packet */
+int tsch_packet_get_frame_pending(uint8_t *buf, int buf_size);
 
 #endif /* __TSCH_PACKET_H__ */
 /** @} */
diff --git a/os/net/mac/tsch/tsch-slot-operation.c b/os/net/mac/tsch/tsch-slot-operation.c
index c4bb25e88..6b47b4ebf 100644
--- a/os/net/mac/tsch/tsch-slot-operation.c
+++ b/os/net/mac/tsch/tsch-slot-operation.c
@@ -167,6 +167,11 @@ static struct tsch_link *backup_link = NULL;
 static struct tsch_packet *current_packet = NULL;
 static struct tsch_neighbor *current_neighbor = NULL;
 
+/* Indicates whether an extra link is needed to handle the current burst */
+static int burst_link_scheduled = 0;
+/* Counts the length of the current burst */
+int tsch_current_burst_count = 0;
+
 /* Protothread for association */
 PT_THREAD(tsch_scan(struct pt *pt));
 /* Protothread for slot operation, called from rtimer interrupt
@@ -456,6 +461,8 @@ PT_THREAD(tsch_tx_slot(struct pt *pt, struct rtimer *t))
       /* is this a broadcast packet? (wait for ack?) */
       static uint8_t is_broadcast;
       static rtimer_clock_t tx_start_time;
+      /* Did we set the frame pending bit to request an extra burst link? */
+      static int burst_link_requested;
 
 #if CCA_ENABLED
       static uint8_t cca_status;
@@ -466,6 +473,13 @@ PT_THREAD(tsch_tx_slot(struct pt *pt, struct rtimer *t))
       packet_len = queuebuf_datalen(current_packet->qb);
       /* is this a broadcast packet? (wait for ack?) */
       is_broadcast = current_neighbor->is_broadcast;
+      /* Unicast. More packets in queue for the neighbor? */
+      burst_link_requested = 0;
+      if(!is_broadcast && (current_link->link_options & LINK_OPTION_BURST)
+             && tsch_queue_packet_count(&current_neighbor->addr) > 1) {
+        burst_link_requested = 1;
+        tsch_packet_set_frame_pending(packet, packet_len);
+      }
       /* read seqno from payload */
       seqno = ((uint8_t *)(packet))[2];
       /* if this is an EB, then update its Sync-IE */
@@ -618,6 +632,12 @@ PT_THREAD(tsch_tx_slot(struct pt *pt, struct rtimer *t))
                   tsch_schedule_keepalive();
                 }
                 mac_tx_status = MAC_TX_OK;
+
+                /* We requested an extra slot and got an ack. This means
+                the extra slot will be scheduled at the received */
+                if(burst_link_requested) {
+                  burst_link_scheduled = 1;
+                }
               } else {
                 mac_tx_status = MAC_TX_NOACK;
               }
@@ -844,6 +864,9 @@ PT_THREAD(tsch_rx_slot(struct pt *pt, struct rtimer *t))
                 TSCH_DEBUG_RX_EVENT();
                 NETSTACK_RADIO.transmit(ack_len);
                 tsch_radio_off(TSCH_RADIO_CMD_OFF_WITHIN_TIMESLOT);
+
+                /* Schedule a burst link iff the frame pending bit was set */
+                burst_link_scheduled = tsch_packet_get_frame_pending(current_input->payload, current_input->len);
               }
             }
 
@@ -930,6 +953,8 @@ PT_THREAD(tsch_slot_operation(struct rtimer *t, void *ptr))
       /* Reset drift correction */
       drift_correction = 0;
       is_drift_correction_used = 0;
+      /* For the packet burst mechanism */
+      burst_link_scheduled = 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
@@ -993,13 +1018,27 @@ PT_THREAD(tsch_slot_operation(struct rtimer *t, void *ptr))
           tsch_queue_update_all_backoff_windows(&current_link->addr);
         }
 
-        /* Get next active link */
-        current_link = tsch_schedule_get_next_active_link(&tsch_current_asn, &timeslot_diff, &backup_link);
-        if(current_link == NULL) {
-          /* There is no next link. Fall back to default
-           * behavior: wake up at the next slot. */
+        /* A burst link was scheduled. Replay the current link at the
+        next time offset */
+        if(burst_link_scheduled) {
           timeslot_diff = 1;
+          backup_link = NULL;
+          /* Keep track of the number of repetitions */
+          tsch_current_burst_count++;
+        } else {
+          /* Get next active link */
+          current_link = tsch_schedule_get_next_active_link(&tsch_current_asn, &timeslot_diff, &backup_link);
+          if(current_link == NULL) {
+            /* There is no next link. Fall back to default
+             * behavior: wake up at the next slot. */
+            timeslot_diff = 1;
+          } else {
+            /* Reset burst index now that the link was scheduled from
+              normal schedule (as opposed to from ongoing burst) */
+            tsch_current_burst_count = 0;
+          }
         }
+
         /* Update ASN */
         TSCH_ASN_INC(tsch_current_asn, timeslot_diff);
         /* Time to next wake up */
diff --git a/os/net/mac/tsch/tsch-slot-operation.h b/os/net/mac/tsch/tsch-slot-operation.h
index 1c71c5587..b1c05697b 100644
--- a/os/net/mac/tsch/tsch-slot-operation.h
+++ b/os/net/mac/tsch/tsch-slot-operation.h
@@ -57,6 +57,8 @@ extern struct ringbufindex input_ringbuf;
 extern struct input_packet input_array[TSCH_MAX_INCOMING_PACKETS];
 /* Last clock_time_t where synchronization happened */
 extern clock_time_t last_sync_time;
+/* Counts the length of the current burst */
+extern int tsch_current_burst_count;
 
 /********** Functions *********/
 

From c41057fc1be9720087ce0a10fb1f9af74c8aa622 Mon Sep 17 00:00:00 2001
From: Simon Duquennoy <simon.duquennoy@ri.se>
Date: Mon, 26 Mar 2018 11:15:45 -0700
Subject: [PATCH 02/10] TSCH: cleaner logging of burst mode

---
 os/net/mac/tsch/tsch-log.c | 6 ++++--
 os/net/mac/tsch/tsch-log.h | 1 +
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/os/net/mac/tsch/tsch-log.c b/os/net/mac/tsch/tsch-log.c
index d27dac064..5aa6f1e69 100644
--- a/os/net/mac/tsch/tsch-log.c
+++ b/os/net/mac/tsch/tsch-log.c
@@ -82,9 +82,10 @@ tsch_log_process_pending(void)
       printf("[INFO: TSCH-LOG  ] {asn %02x.%08lx link-NULL} ", log->asn.ms1b, log->asn.ls4b);
     } else {
       struct tsch_slotframe *sf = tsch_schedule_get_slotframe_by_handle(log->link->slotframe_handle);
-      printf("[INFO: TSCH-LOG  ] {asn %02x.%08lx link %2u %3u %3u %2u ch %2u} ",
+      printf("[INFO: TSCH-LOG  ] {asn %02x.%08lx link %2u %3u %3u %2u %2u ch %2u} ",
              log->asn.ms1b, log->asn.ls4b,
-             log->link->slotframe_handle, sf ? sf->size.val : 0, log->link->timeslot, log->link->channel_offset,
+             log->link->slotframe_handle, sf ? sf->size.val : 0,
+             log->burst_count, log->link->timeslot + log->burst_count, log->link->channel_offset,
              tsch_calculate_channel(&log->asn, log->link->channel_offset));
     }
     switch(log->type) {
@@ -135,6 +136,7 @@ tsch_log_prepare_add(void)
     struct tsch_log_t *log = &log_array[log_index];
     log->asn = tsch_current_asn;
     log->link = current_link;
+    log->burst_count = tsch_current_burst_count;
     return log;
   } else {
     log_dropped++;
diff --git a/os/net/mac/tsch/tsch-log.h b/os/net/mac/tsch/tsch-log.h
index 468eff869..8064922fd 100644
--- a/os/net/mac/tsch/tsch-log.h
+++ b/os/net/mac/tsch/tsch-log.h
@@ -80,6 +80,7 @@ struct tsch_log_t {
   } type;
   struct tsch_asn_t asn;
   struct tsch_link *link;
+  uint8_t burst_count;
   union {
     char message[48];
     struct {

From d3b8b80b2808c29dcb37532cc7f675453ad42e27 Mon Sep 17 00:00:00 2001
From: Simon Duquennoy <simon.duquennoy@ri.se>
Date: Mon, 26 Mar 2018 11:22:31 -0700
Subject: [PATCH 03/10] TSCH: add option to run 6TiSCH minimal with burst mode
 enabled

---
 os/net/mac/tsch/tsch-conf.h     | 7 +++++++
 os/net/mac/tsch/tsch-schedule.c | 3 ++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/os/net/mac/tsch/tsch-conf.h b/os/net/mac/tsch/tsch-conf.h
index 3ee47b9cb..934e0884f 100644
--- a/os/net/mac/tsch/tsch-conf.h
+++ b/os/net/mac/tsch/tsch-conf.h
@@ -317,6 +317,13 @@
 #define TSCH_SCHEDULE_WITH_6TISCH_MINIMAL (!(BUILD_WITH_ORCHESTRA))
 #endif
 
+/* Add burst mode to 6TiSCH minimal schedule */
+#ifdef TSCH_SCHEDULE_CONF_WITH_6TISCH_MINIMAL_WITH_BURST
+#define TSCH_SCHEDULE_WITH_6TISCH_MINIMAL_WITH_BURST TSCH_SCHEDULE_CONF_WITH_6TISCH_MINIMAL_WITH_BURST
+#else
+#define TSCH_SCHEDULE_WITH_6TISCH_MINIMAL_WITH_BURST 0
+#endif
+
 /* 6TiSCH Minimal schedule slotframe length */
 #ifdef TSCH_SCHEDULE_CONF_DEFAULT_LENGTH
 #define TSCH_SCHEDULE_DEFAULT_LENGTH TSCH_SCHEDULE_CONF_DEFAULT_LENGTH
diff --git a/os/net/mac/tsch/tsch-schedule.c b/os/net/mac/tsch/tsch-schedule.c
index 70a6b92ae..d5bf49653 100644
--- a/os/net/mac/tsch/tsch-schedule.c
+++ b/os/net/mac/tsch/tsch-schedule.c
@@ -423,7 +423,8 @@ tsch_schedule_create_minimal(void)
    * but is required according to 802.15.4e if also used for EB transmission.
    * Timeslot: 0, channel offset: 0. */
   tsch_schedule_add_link(sf_min,
-      LINK_OPTION_RX | LINK_OPTION_TX | LINK_OPTION_SHARED | LINK_OPTION_TIME_KEEPING,
+      LINK_OPTION_RX | LINK_OPTION_TX | LINK_OPTION_SHARED | LINK_OPTION_TIME_KEEPING
+        | (TSCH_SCHEDULE_WITH_6TISCH_MINIMAL_WITH_BURST ? LINK_OPTION_BURST : 0),
       LINK_TYPE_ADVERTISING, &tsch_broadcast_address,
       0, 0);
 }

From 3fe846dbada52ef4b1a738340ff073514bb65a2e Mon Sep 17 00:00:00 2001
From: Simon Duquennoy <simon.duquennoy@ri.se>
Date: Mon, 26 Mar 2018 11:35:35 -0700
Subject: [PATCH 04/10] TSCH burst mode: bounded burst lengths

---
 os/net/mac/tsch/tsch-conf.h           | 13 ++++++++++---
 os/net/mac/tsch/tsch-schedule.c       |  2 +-
 os/net/mac/tsch/tsch-slot-operation.c |  1 +
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/os/net/mac/tsch/tsch-conf.h b/os/net/mac/tsch/tsch-conf.h
index 934e0884f..afd90aaef 100644
--- a/os/net/mac/tsch/tsch-conf.h
+++ b/os/net/mac/tsch/tsch-conf.h
@@ -318,10 +318,17 @@
 #endif
 
 /* Add burst mode to 6TiSCH minimal schedule */
-#ifdef TSCH_SCHEDULE_CONF_WITH_6TISCH_MINIMAL_WITH_BURST
-#define TSCH_SCHEDULE_WITH_6TISCH_MINIMAL_WITH_BURST TSCH_SCHEDULE_CONF_WITH_6TISCH_MINIMAL_WITH_BURST
+#ifdef TSCH_CONF_WITH_6TISCH_MINIMAL_WITH_BURST
+#define TSCH_WITH_6TISCH_MINIMAL_WITH_BURST TSCH_CONF_WITH_6TISCH_MINIMAL_WITH_BURST
 #else
-#define TSCH_SCHEDULE_WITH_6TISCH_MINIMAL_WITH_BURST 0
+#define TSCH_WITH_6TISCH_MINIMAL_WITH_BURST 0
+#endif
+
+/* Set an upper bound on burst length */
+#ifdef TSCH_CONF_BURST_MAX_LEN
+#define TSCH_BURST_MAX_LEN TSCH_CONF_BURST_MAX_LEN
+#else
+#define TSCH_BURST_MAX_LEN 32
 #endif
 
 /* 6TiSCH Minimal schedule slotframe length */
diff --git a/os/net/mac/tsch/tsch-schedule.c b/os/net/mac/tsch/tsch-schedule.c
index d5bf49653..a03363eb9 100644
--- a/os/net/mac/tsch/tsch-schedule.c
+++ b/os/net/mac/tsch/tsch-schedule.c
@@ -424,7 +424,7 @@ tsch_schedule_create_minimal(void)
    * Timeslot: 0, channel offset: 0. */
   tsch_schedule_add_link(sf_min,
       LINK_OPTION_RX | LINK_OPTION_TX | LINK_OPTION_SHARED | LINK_OPTION_TIME_KEEPING
-        | (TSCH_SCHEDULE_WITH_6TISCH_MINIMAL_WITH_BURST ? LINK_OPTION_BURST : 0),
+        | (TSCH_WITH_6TISCH_MINIMAL_WITH_BURST ? LINK_OPTION_BURST : 0),
       LINK_TYPE_ADVERTISING, &tsch_broadcast_address,
       0, 0);
 }
diff --git a/os/net/mac/tsch/tsch-slot-operation.c b/os/net/mac/tsch/tsch-slot-operation.c
index 6b47b4ebf..a2e9982fe 100644
--- a/os/net/mac/tsch/tsch-slot-operation.c
+++ b/os/net/mac/tsch/tsch-slot-operation.c
@@ -476,6 +476,7 @@ PT_THREAD(tsch_tx_slot(struct pt *pt, struct rtimer *t))
       /* Unicast. More packets in queue for the neighbor? */
       burst_link_requested = 0;
       if(!is_broadcast && (current_link->link_options & LINK_OPTION_BURST)
+             && tsch_current_burst_count + 1 < TSCH_BURST_MAX_LEN
              && tsch_queue_packet_count(&current_neighbor->addr) > 1) {
         burst_link_requested = 1;
         tsch_packet_set_frame_pending(packet, packet_len);

From 5607308eed2540cc3fe10edf7c5902b6152ef64e Mon Sep 17 00:00:00 2001
From: Simon Duquennoy <simon.duquennoy@ri.se>
Date: Sun, 15 Apr 2018 04:18:33 -0700
Subject: [PATCH 05/10] Added doxygen for TSCH frame pending bit functions

---
 os/net/mac/tsch/tsch-packet.h | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/os/net/mac/tsch/tsch-packet.h b/os/net/mac/tsch/tsch-packet.h
index a7426ebac..cdf7c7bed 100644
--- a/os/net/mac/tsch/tsch-packet.h
+++ b/os/net/mac/tsch/tsch-packet.h
@@ -101,9 +101,18 @@ int tsch_packet_update_eb(uint8_t *buf, int buf_size, uint8_t tsch_sync_ie_offse
 int tsch_packet_parse_eb(const uint8_t *buf, int buf_size,
     frame802154_t *frame, struct ieee802154_ies *ies,
     uint8_t *hdrlen, int frame_without_mic);
-/* Set frame pending bit in a packet (whose header was already build) */
+/**
+ * \brief Set frame pending bit in a packet (whose header was already build)
+ * \param buf The buffer where the packet resides
+ * \param buf_size The buffer size
+ */
 void tsch_packet_set_frame_pending(uint8_t *buf, int buf_size);
-/* Get frame pending bit from a packet */
+/**
+ * \brief Get frame pending bit from a packet
+ * \param buf The buffer where the packet resides
+ * \param buf_size The buffer size
+ * \return The value of the frame pending bit, 1 or 0
+ */
 int tsch_packet_get_frame_pending(uint8_t *buf, int buf_size);
 
 #endif /* __TSCH_PACKET_H__ */

From 243386044158d4b792976d8dce48526b13846ede Mon Sep 17 00:00:00 2001
From: Simon Duquennoy <simon.duquennoy@ri.se>
Date: Sat, 12 May 2018 10:49:44 -0700
Subject: [PATCH 06/10] TSCH burst mode: do not channel hop within burst

---
 os/net/mac/tsch/tsch-slot-operation.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/os/net/mac/tsch/tsch-slot-operation.c b/os/net/mac/tsch/tsch-slot-operation.c
index a2e9982fe..7a26e4d81 100644
--- a/os/net/mac/tsch/tsch-slot-operation.c
+++ b/os/net/mac/tsch/tsch-slot-operation.c
@@ -171,6 +171,8 @@ static struct tsch_neighbor *current_neighbor = NULL;
 static int burst_link_scheduled = 0;
 /* Counts the length of the current burst */
 int tsch_current_burst_count = 0;
+/* The physical channel of the current burst */
+static uint16_t burst_current_channel = 0;
 
 /* Protothread for association */
 PT_THREAD(tsch_scan(struct pt *pt));
@@ -954,8 +956,6 @@ PT_THREAD(tsch_slot_operation(struct rtimer *t, void *ptr))
       /* Reset drift correction */
       drift_correction = 0;
       is_drift_correction_used = 0;
-      /* For the packet burst mechanism */
-      burst_link_scheduled = 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
@@ -966,8 +966,15 @@ PT_THREAD(tsch_slot_operation(struct rtimer *t, void *ptr))
       }
       is_active_slot = current_packet != NULL || (current_link->link_options & LINK_OPTION_RX);
       if(is_active_slot) {
-        /* Hop channel */
-        current_channel = tsch_calculate_channel(&tsch_current_asn, current_link->channel_offset);
+        /* If we are in a burst, we stick to current channel instead of
+         * doing channel hopping, as per IEEE 802.15.4-2015 */
+        if(burst_link_scheduled) {
+          current_channel = burst_current_channel;
+          burst_link_scheduled = 0;
+        } else {
+          /* Hop channel */
+          current_channel = tsch_calculate_channel(&tsch_current_asn, current_link->channel_offset);
+        }
         NETSTACK_RADIO.set_value(RADIO_PARAM_CHANNEL, current_channel);
         /* Turn the radio on already here if configured so; necessary for radios with slow startup */
         tsch_radio_on(TSCH_RADIO_CMD_ON_START_OF_TIMESLOT);
@@ -986,6 +993,10 @@ PT_THREAD(tsch_slot_operation(struct rtimer *t, void *ptr))
           static struct pt slot_rx_pt;
           PT_SPAWN(&slot_operation_pt, &slot_rx_pt, tsch_rx_slot(&slot_rx_pt, t));
         }
+      } else {
+        /* Make sure to end the burst in cast, for some reason, we were
+         * in a burst but now without any more packet to send. */
+        burst_link_scheduled = 0;
       }
       TSCH_DEBUG_SLOT_END();
     }
@@ -1023,6 +1034,7 @@ PT_THREAD(tsch_slot_operation(struct rtimer *t, void *ptr))
         next time offset */
         if(burst_link_scheduled) {
           timeslot_diff = 1;
+          burst_current_channel = current_channel;
           backup_link = NULL;
           /* Keep track of the number of repetitions */
           tsch_current_burst_count++;

From 0153566b928cb59ff02004dfb37033a560e5716f Mon Sep 17 00:00:00 2001
From: Simon Duquennoy <simon.duquennoy@ri.se>
Date: Sat, 12 May 2018 10:53:24 -0700
Subject: [PATCH 07/10] TSCH burst mode: fix logging

---
 os/net/mac/tsch/tsch-log.c            |  3 ++-
 os/net/mac/tsch/tsch-log.h            |  1 +
 os/net/mac/tsch/tsch-slot-operation.c | 14 +++++++-------
 os/net/mac/tsch/tsch.h                |  2 ++
 4 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/os/net/mac/tsch/tsch-log.c b/os/net/mac/tsch/tsch-log.c
index 5aa6f1e69..e705f50ab 100644
--- a/os/net/mac/tsch/tsch-log.c
+++ b/os/net/mac/tsch/tsch-log.c
@@ -86,7 +86,7 @@ tsch_log_process_pending(void)
              log->asn.ms1b, log->asn.ls4b,
              log->link->slotframe_handle, sf ? sf->size.val : 0,
              log->burst_count, log->link->timeslot + log->burst_count, log->link->channel_offset,
-             tsch_calculate_channel(&log->asn, log->link->channel_offset));
+             log->channel);
     }
     switch(log->type) {
       case tsch_log_tx:
@@ -137,6 +137,7 @@ tsch_log_prepare_add(void)
     log->asn = tsch_current_asn;
     log->link = current_link;
     log->burst_count = tsch_current_burst_count;
+    log->channel = tsch_current_channel;
     return log;
   } else {
     log_dropped++;
diff --git a/os/net/mac/tsch/tsch-log.h b/os/net/mac/tsch/tsch-log.h
index 8064922fd..186cda120 100644
--- a/os/net/mac/tsch/tsch-log.h
+++ b/os/net/mac/tsch/tsch-log.h
@@ -81,6 +81,7 @@ struct tsch_log_t {
   struct tsch_asn_t asn;
   struct tsch_link *link;
   uint8_t burst_count;
+  uint8_t channel;
   union {
     char message[48];
     struct {
diff --git a/os/net/mac/tsch/tsch-slot-operation.c b/os/net/mac/tsch/tsch-slot-operation.c
index 7a26e4d81..bc76b526e 100644
--- a/os/net/mac/tsch/tsch-slot-operation.c
+++ b/os/net/mac/tsch/tsch-slot-operation.c
@@ -155,7 +155,7 @@ static rtimer_clock_t volatile current_slot_start;
 static volatile int tsch_in_slot_operation = 0;
 
 /* If we are inside a slot, this tells the current channel */
-static uint8_t current_channel;
+uint8_t tsch_current_channel;
 
 /* Info about the link, packet and neighbor of
  * the current (or next) slot */
@@ -172,7 +172,7 @@ static int burst_link_scheduled = 0;
 /* Counts the length of the current burst */
 int tsch_current_burst_count = 0;
 /* The physical channel of the current burst */
-static uint16_t burst_current_channel = 0;
+static uint16_t burst_tsch_current_channel = 0;
 
 /* Protothread for association */
 PT_THREAD(tsch_scan(struct pt *pt));
@@ -772,7 +772,7 @@ PT_THREAD(tsch_rx_slot(struct pt *pt, struct rtimer *t))
         NETSTACK_RADIO.get_value(RADIO_PARAM_LAST_RSSI, &radio_last_rssi);
         current_input->rx_asn = tsch_current_asn;
         current_input->rssi = (signed)radio_last_rssi;
-        current_input->channel = current_channel;
+        current_input->channel = tsch_current_channel;
         header_len = frame802154_parse((uint8_t *)current_input->payload, current_input->len, &frame);
         frame_valid = header_len > 0 &&
           frame802154_check_dest_panid(&frame) &&
@@ -969,13 +969,13 @@ PT_THREAD(tsch_slot_operation(struct rtimer *t, void *ptr))
         /* If we are in a burst, we stick to current channel instead of
          * doing channel hopping, as per IEEE 802.15.4-2015 */
         if(burst_link_scheduled) {
-          current_channel = burst_current_channel;
+          tsch_current_channel = burst_tsch_current_channel;
           burst_link_scheduled = 0;
         } else {
           /* Hop channel */
-          current_channel = tsch_calculate_channel(&tsch_current_asn, current_link->channel_offset);
+          tsch_current_channel = tsch_calculate_channel(&tsch_current_asn, current_link->channel_offset);
         }
-        NETSTACK_RADIO.set_value(RADIO_PARAM_CHANNEL, current_channel);
+        NETSTACK_RADIO.set_value(RADIO_PARAM_CHANNEL, tsch_current_channel);
         /* Turn the radio on already here if configured so; necessary for radios with slow startup */
         tsch_radio_on(TSCH_RADIO_CMD_ON_START_OF_TIMESLOT);
         /* Decide whether it is a TX/RX/IDLE or OFF slot */
@@ -1034,7 +1034,7 @@ PT_THREAD(tsch_slot_operation(struct rtimer *t, void *ptr))
         next time offset */
         if(burst_link_scheduled) {
           timeslot_diff = 1;
-          burst_current_channel = current_channel;
+          burst_tsch_current_channel = tsch_current_channel;
           backup_link = NULL;
           /* Keep track of the number of repetitions */
           tsch_current_burst_count++;
diff --git a/os/net/mac/tsch/tsch.h b/os/net/mac/tsch/tsch.h
index 0f108bd93..93b6e0d88 100644
--- a/os/net/mac/tsch/tsch.h
+++ b/os/net/mac/tsch/tsch.h
@@ -164,6 +164,8 @@ extern const linkaddr_t tsch_eb_address;
 extern struct tsch_asn_t tsch_current_asn;
 extern uint8_t tsch_join_priority;
 extern struct tsch_link *current_link;
+/* If we are inside a slot, this tells the current channel */
+extern uint8_t tsch_current_channel;
 /* TSCH channel hopping sequence */
 extern uint8_t tsch_hopping_sequence[TSCH_HOPPING_SEQUENCE_MAX_LEN];
 extern struct tsch_asn_divisor_t tsch_hopping_sequence_length;

From 9569519bbe933b3d33ab7ab027cde6222efe6616 Mon Sep 17 00:00:00 2001
From: Simon Duquennoy <simon.duquennoy@ri.se>
Date: Sat, 12 May 2018 11:20:14 -0700
Subject: [PATCH 08/10] TSCH: burst mode is in the standard, remove custom link
 option

---
 os/net/mac/tsch/tsch-conf.h           | 11 +++--------
 os/net/mac/tsch/tsch-const.h          |  1 -
 os/net/mac/tsch/tsch-schedule.c       |  3 +--
 os/net/mac/tsch/tsch-slot-operation.c |  2 +-
 4 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/os/net/mac/tsch/tsch-conf.h b/os/net/mac/tsch/tsch-conf.h
index afd90aaef..8613eb0e3 100644
--- a/os/net/mac/tsch/tsch-conf.h
+++ b/os/net/mac/tsch/tsch-conf.h
@@ -317,14 +317,9 @@
 #define TSCH_SCHEDULE_WITH_6TISCH_MINIMAL (!(BUILD_WITH_ORCHESTRA))
 #endif
 
-/* Add burst mode to 6TiSCH minimal schedule */
-#ifdef TSCH_CONF_WITH_6TISCH_MINIMAL_WITH_BURST
-#define TSCH_WITH_6TISCH_MINIMAL_WITH_BURST TSCH_CONF_WITH_6TISCH_MINIMAL_WITH_BURST
-#else
-#define TSCH_WITH_6TISCH_MINIMAL_WITH_BURST 0
-#endif
-
-/* Set an upper bound on burst length */
+/* Set an upper bound on burst length. Set to 0 to never set the frame pending
+ * bit, i.e., never trigger a burst. Note that receiver-side support for burst
+ * is always enabled, as it is part of IEEE 802.1.5.4-2015 (Section 7.2.1.3)*/
 #ifdef TSCH_CONF_BURST_MAX_LEN
 #define TSCH_BURST_MAX_LEN TSCH_CONF_BURST_MAX_LEN
 #else
diff --git a/os/net/mac/tsch/tsch-const.h b/os/net/mac/tsch/tsch-const.h
index 51e7d0625..81ca7ffa8 100644
--- a/os/net/mac/tsch/tsch-const.h
+++ b/os/net/mac/tsch/tsch-const.h
@@ -53,7 +53,6 @@
 #define LINK_OPTION_RX              2
 #define LINK_OPTION_SHARED          4
 #define LINK_OPTION_TIME_KEEPING    8
-#define LINK_OPTION_BURST          16
 
 /* Default IEEE 802.15.4e hopping sequences, obtained from https://gist.github.com/twatteyne/2e22ee3c1a802b685695 */
 /* 16 channels, sequence length 16 */
diff --git a/os/net/mac/tsch/tsch-schedule.c b/os/net/mac/tsch/tsch-schedule.c
index a03363eb9..4f94b8e30 100644
--- a/os/net/mac/tsch/tsch-schedule.c
+++ b/os/net/mac/tsch/tsch-schedule.c
@@ -423,8 +423,7 @@ tsch_schedule_create_minimal(void)
    * but is required according to 802.15.4e if also used for EB transmission.
    * Timeslot: 0, channel offset: 0. */
   tsch_schedule_add_link(sf_min,
-      LINK_OPTION_RX | LINK_OPTION_TX | LINK_OPTION_SHARED | LINK_OPTION_TIME_KEEPING
-        | (TSCH_WITH_6TISCH_MINIMAL_WITH_BURST ? LINK_OPTION_BURST : 0),
+      (LINK_OPTION_RX | LINK_OPTION_TX | LINK_OPTION_SHARED | LINK_OPTION_TIME_KEEPING),
       LINK_TYPE_ADVERTISING, &tsch_broadcast_address,
       0, 0);
 }
diff --git a/os/net/mac/tsch/tsch-slot-operation.c b/os/net/mac/tsch/tsch-slot-operation.c
index bc76b526e..de4dec676 100644
--- a/os/net/mac/tsch/tsch-slot-operation.c
+++ b/os/net/mac/tsch/tsch-slot-operation.c
@@ -477,7 +477,7 @@ PT_THREAD(tsch_tx_slot(struct pt *pt, struct rtimer *t))
       is_broadcast = current_neighbor->is_broadcast;
       /* Unicast. More packets in queue for the neighbor? */
       burst_link_requested = 0;
-      if(!is_broadcast && (current_link->link_options & LINK_OPTION_BURST)
+      if(!is_broadcast
              && tsch_current_burst_count + 1 < TSCH_BURST_MAX_LEN
              && tsch_queue_packet_count(&current_neighbor->addr) > 1) {
         burst_link_requested = 1;

From 359ae59499760f17ca1bc73ac4b4da895f6056d4 Mon Sep 17 00:00:00 2001
From: Simon Duquennoy <simon.duquennoy@ri.se>
Date: Sun, 13 May 2018 06:47:37 -0700
Subject: [PATCH 09/10] tsch-packet: define constant for frame pending bit
 offset

---
 os/net/mac/tsch/tsch-packet.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/os/net/mac/tsch/tsch-packet.c b/os/net/mac/tsch/tsch-packet.c
index 5f6cb6b54..133e9a668 100644
--- a/os/net/mac/tsch/tsch-packet.c
+++ b/os/net/mac/tsch/tsch-packet.c
@@ -70,6 +70,9 @@
  */
 static struct packetbuf_attr eackbuf_attrs[PACKETBUF_NUM_ATTRS];
 
+/* The offset of the frame pending bit flag within the first byte of FCF */
+#define IEEE802154_FRAME_PENDING_BIT_OFFSET 4
+
 /*---------------------------------------------------------------------------*/
 static int
 tsch_packet_eackbuf_set_attr(uint8_t type, const packetbuf_attr_t val)
@@ -463,14 +466,14 @@ tsch_packet_parse_eb(const uint8_t *buf, int buf_size,
 void
 tsch_packet_set_frame_pending(uint8_t *buf, int buf_size)
 {
-  buf[0] |= (1 << 4);
+  buf[0] |= (1 << IEEE802154_FRAME_PENDING_BIT_OFFSET);
 }
 /*---------------------------------------------------------------------------*/
 /* Get frame pending bit from a packet */
 int
 tsch_packet_get_frame_pending(uint8_t *buf, int buf_size)
 {
-  return (buf[0] >> 4) & 1;
+  return (buf[0] >> IEEE802154_FRAME_PENDING_BIT_OFFSET) & 1;
 }
 /*---------------------------------------------------------------------------*/
 /** @} */

From 2bf79a98ce9727c2c547b4ba3ed0bcea1778d3ef Mon Sep 17 00:00:00 2001
From: Simon Duquennoy <simon.duquennoy@ri.se>
Date: Sun, 13 May 2018 06:49:52 -0700
Subject: [PATCH 10/10] TSCH burst mode: remove unnecessary variable
 burst_tsch_current_channel

---
 os/net/mac/tsch/tsch-slot-operation.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/os/net/mac/tsch/tsch-slot-operation.c b/os/net/mac/tsch/tsch-slot-operation.c
index de4dec676..917d13816 100644
--- a/os/net/mac/tsch/tsch-slot-operation.c
+++ b/os/net/mac/tsch/tsch-slot-operation.c
@@ -171,8 +171,6 @@ static struct tsch_neighbor *current_neighbor = NULL;
 static int burst_link_scheduled = 0;
 /* Counts the length of the current burst */
 int tsch_current_burst_count = 0;
-/* The physical channel of the current burst */
-static uint16_t burst_tsch_current_channel = 0;
 
 /* Protothread for association */
 PT_THREAD(tsch_scan(struct pt *pt));
@@ -969,7 +967,7 @@ PT_THREAD(tsch_slot_operation(struct rtimer *t, void *ptr))
         /* If we are in a burst, we stick to current channel instead of
          * doing channel hopping, as per IEEE 802.15.4-2015 */
         if(burst_link_scheduled) {
-          tsch_current_channel = burst_tsch_current_channel;
+          /* Reset burst_link_scheduled flag. Will be set again if burst continue. */
           burst_link_scheduled = 0;
         } else {
           /* Hop channel */
@@ -1034,7 +1032,6 @@ PT_THREAD(tsch_slot_operation(struct rtimer *t, void *ptr))
         next time offset */
         if(burst_link_scheduled) {
           timeslot_diff = 1;
-          burst_tsch_current_channel = tsch_current_channel;
           backup_link = NULL;
           /* Keep track of the number of repetitions */
           tsch_current_burst_count++;