Ejemplo n.º 1
0
/*---------------------------------------------------------------------------*/
static char
powercycle(struct rtimer *t, void *ptr)
{
#if SYNC_CYCLE_STARTS
  static volatile rtimer_clock_t sync_cycle_start;
  static volatile uint8_t sync_cycle_phase;
#endif

  PT_BEGIN(&pt);

#if SYNC_CYCLE_STARTS
  sync_cycle_start = RTIMER_NOW();
#else
  cycle_start = RTIMER_NOW();
#endif

  while(1) {
    static uint8_t packet_seen;
    static rtimer_clock_t t0;
    static uint8_t count;

#if SYNC_CYCLE_STARTS
    /* Compute cycle start when RTIMER_ARCH_SECOND is not a multiple
       of CHANNEL_CHECK_RATE */
    if(sync_cycle_phase++ == NETSTACK_RDC_CHANNEL_CHECK_RATE) {
      sync_cycle_phase = 0;
      sync_cycle_start += RTIMER_ARCH_SECOND;
      cycle_start = sync_cycle_start;
    } else {
#if (RTIMER_ARCH_SECOND * NETSTACK_RDC_CHANNEL_CHECK_RATE) > 65535
      cycle_start = sync_cycle_start + ((unsigned long)(sync_cycle_phase*RTIMER_ARCH_SECOND))/NETSTACK_RDC_CHANNEL_CHECK_RATE;
#else
      cycle_start = sync_cycle_start + (sync_cycle_phase*RTIMER_ARCH_SECOND)/NETSTACK_RDC_CHANNEL_CHECK_RATE;
#endif
    }
#else
    cycle_start += CYCLE_TIME;
#endif

    packet_seen = 0;

    for(count = 0; count < CCA_COUNT_MAX; ++count) {
      t0 = RTIMER_NOW();
      if(we_are_sending == 0 && we_are_receiving_burst == 0) {
        powercycle_turn_radio_on();
        /* Check if a packet is seen in the air. If so, we keep the
             radio on for a while (LISTEN_TIME_AFTER_PACKET_DETECTED) to
             be able to receive the packet. We also continuously check
             the radio medium to make sure that we wasn't woken up by a
             false positive: a spurious radio interference that was not
             caused by an incoming packet. */
        if(NETSTACK_RADIO.channel_clear() == 0) {
          packet_seen = 1;
          break;
        }
        powercycle_turn_radio_off();
      }
      schedule_powercycle_fixed(t, RTIMER_NOW() + CCA_SLEEP_TIME);
      PT_YIELD(&pt);
    }

    if(packet_seen) {
      static rtimer_clock_t start;
      static uint8_t silence_periods, periods;
      start = RTIMER_NOW();

      periods = silence_periods = 0;
      while(we_are_sending == 0 && radio_is_on &&
            RTIMER_CLOCK_LT(RTIMER_NOW(),
                            (start + LISTEN_TIME_AFTER_PACKET_DETECTED))) {

        /* Check for a number of consecutive periods of
             non-activity. If we see two such periods, we turn the
             radio off. Also, if a packet has been successfully
             received (as indicated by the
             NETSTACK_RADIO.pending_packet() function), we stop
             snooping. */
#if !RDC_CONF_HARDWARE_CSMA
       /* A cca cycle will disrupt rx on some radios, e.g. mc1322x, rf230 */
       /*TODO: Modify those drivers to just return the internal RSSI when already in rx mode */
        if(NETSTACK_RADIO.channel_clear()) {
          ++silence_periods;
        } else {
          silence_periods = 0;
        }
#endif

        ++periods;

        if(NETSTACK_RADIO.receiving_packet()) {
          silence_periods = 0;
        }
        if(silence_periods > MAX_SILENCE_PERIODS) {
          powercycle_turn_radio_off();
          break;
        }
        if(WITH_FAST_SLEEP &&
            periods > MAX_NONACTIVITY_PERIODS &&
            !(NETSTACK_RADIO.receiving_packet() ||
              NETSTACK_RADIO.pending_packet())) {
          powercycle_turn_radio_off();
          break;
        }
        if(NETSTACK_RADIO.pending_packet()) {
          break;
        }

        schedule_powercycle(t, CCA_CHECK_TIME + CCA_SLEEP_TIME);
        PT_YIELD(&pt);
      }
      if(radio_is_on) {
        if(!(NETSTACK_RADIO.receiving_packet() ||
             NETSTACK_RADIO.pending_packet()) ||
             !RTIMER_CLOCK_LT(RTIMER_NOW(),
                 (start + LISTEN_TIME_AFTER_PACKET_DETECTED))) {
          powercycle_turn_radio_off();
        }
      }
    }

    if(RTIMER_CLOCK_LT(RTIMER_NOW() - cycle_start, CYCLE_TIME - CHECK_TIME * 4)) {
      /* Schedule the next powercycle interrupt, or sleep the mcu
	 until then.  Sleeping will not exit from this interrupt, so
	 ensure an occasional wake cycle or foreground processing will
	 be blocked until a packet is detected */
#if RDC_CONF_MCU_SLEEP
      static uint8_t sleepcycle;
      if((sleepcycle++ < 16) && !we_are_sending && !radio_is_on) {
        rtimer_arch_sleep(CYCLE_TIME - (RTIMER_NOW() - cycle_start));
      } else {
        sleepcycle = 0;
        schedule_powercycle_fixed(t, CYCLE_TIME + cycle_start);
        PT_YIELD(&pt);
      }
#else
      schedule_powercycle_fixed(t, CYCLE_TIME + cycle_start);
      PT_YIELD(&pt);
#endif
    }
  }

  PT_END(&pt);
}
Ejemplo n.º 2
0
/*---------------------------------------------------------------------------*/
static void
powercycle_turn_radio_off(void)
{
#if CONTIKIMAC_CONF_COMPOWER
  uint8_t was_on = radio_is_on;
#endif /* CONTIKIMAC_CONF_COMPOWER */
  
#if RDC_CONF_HARDWARE_SEND_ACK
  if(we_are_sending == 0 && we_are_receiving_burst == 0) {
#else
  if(we_are_sending == 0 && we_are_receiving_burst == 0 && we_are_acking == 0) {
#endif
    off();
#if CONTIKIMAC_CONF_COMPOWER
    if(was_on && !radio_is_on) {
      compower_accumulate(&compower_idle_activity);
    }
#endif /* CONTIKIMAC_CONF_COMPOWER */
  }
}
/*---------------------------------------------------------------------------*/
static void
powercycle_turn_radio_on(void)
{
#if RDC_CONF_HARDWARE_SEND_ACK
  if(we_are_sending == 0 && we_are_receiving_burst == 0) {
#else
  if(we_are_sending == 0 && we_are_receiving_burst == 0 && we_are_acking == 0) {
#endif
    on();
  }
}
/*---------------------------------------------------------------------------*/
static char
powercycle(struct rtimer *t, void *ptr)
{
#if SYNC_CYCLE_STARTS
  static volatile rtimer_clock_t sync_cycle_start;
  static volatile uint8_t sync_cycle_phase;
#endif

  PT_BEGIN(&pt);

#if SYNC_CYCLE_STARTS
  sync_cycle_start = RTIMER_NOW();
#else
  cycle_start = RTIMER_NOW();
#endif

  while(1) {
    static uint8_t packet_seen;
    static rtimer_clock_t t0;
    static uint8_t count;

#if SYNC_CYCLE_STARTS
    /* Compute cycle start when RTIMER_ARCH_SECOND is not a multiple
       of CHANNEL_CHECK_RATE */
    if(sync_cycle_phase++ == NETSTACK_RDC_CHANNEL_CHECK_RATE) {
      sync_cycle_phase = 0;
      sync_cycle_start += RTIMER_ARCH_SECOND;
      cycle_start = sync_cycle_start;
    } else {
#if (RTIMER_ARCH_SECOND * NETSTACK_RDC_CHANNEL_CHECK_RATE) > 65535
      cycle_start = sync_cycle_start + ((unsigned long)(sync_cycle_phase*RTIMER_ARCH_SECOND))/NETSTACK_RDC_CHANNEL_CHECK_RATE;
#else
      cycle_start = sync_cycle_start + (sync_cycle_phase*RTIMER_ARCH_SECOND)/NETSTACK_RDC_CHANNEL_CHECK_RATE;
#endif
    }
#else
    cycle_start += CYCLE_TIME;
#endif

    packet_seen = 0;

    for(count = 0; count < CCA_COUNT_MAX; ++count) {
      t0 = RTIMER_NOW();
      if(we_are_sending == 0 && we_are_receiving_burst == 0) {
        powercycle_turn_radio_on();
        /* Check if a packet is seen in the air. If so, we keep the
             radio on for a while (LISTEN_TIME_AFTER_PACKET_DETECTED) to
             be able to receive the packet. We also continuously check
             the radio medium to make sure that we wasn't woken up by a
             false positive: a spurious radio interference that was not
             caused by an incoming packet. */
        if(NETSTACK_RADIO.channel_clear() == 0) {
          packet_seen = 1;
          break;
        }
        powercycle_turn_radio_off();
      }
      schedule_powercycle_fixed(t, RTIMER_NOW() + CCA_SLEEP_TIME);
      PT_YIELD(&pt);
    }

    if(packet_seen) {
      static rtimer_clock_t start;
      static uint8_t silence_periods, periods;
      start = RTIMER_NOW();

      periods = silence_periods = 0;
      while(we_are_sending == 0 && radio_is_on &&
            RTIMER_CLOCK_LT(RTIMER_NOW(),
                            (start + LISTEN_TIME_AFTER_PACKET_DETECTED))) {

        /* Check for a number of consecutive periods of
             non-activity. If we see two such periods, we turn the
             radio off. Also, if a packet has been successfully
             received (as indicated by the
             NETSTACK_RADIO.pending_packet() function), we stop
             snooping. */
#if !RDC_CONF_HARDWARE_CSMA
       /* A cca cycle will disrupt rx on some radios, e.g. mc1322x, rf230 */
       /*TODO: Modify those drivers to just return the internal RSSI when already in rx mode */
        if(NETSTACK_RADIO.channel_clear()) {
          ++silence_periods;
        } else {
          silence_periods = 0;
        }
#endif

        ++periods;

        if(NETSTACK_RADIO.receiving_packet()) {
          silence_periods = 0;
        }
        if(silence_periods > MAX_SILENCE_PERIODS) {
          powercycle_turn_radio_off();
          break;
        }
        if(WITH_FAST_SLEEP &&
            periods > MAX_NONACTIVITY_PERIODS &&
            !(NETSTACK_RADIO.receiving_packet() ||
              NETSTACK_RADIO.pending_packet())) {
          powercycle_turn_radio_off();
          break;
        }
        if(NETSTACK_RADIO.pending_packet()) {
          break;
        }

        schedule_powercycle(t, CCA_CHECK_TIME + CCA_SLEEP_TIME);
        PT_YIELD(&pt);
      }
      if(radio_is_on) {
        if(!(NETSTACK_RADIO.receiving_packet() ||
             NETSTACK_RADIO.pending_packet()) ||
             !RTIMER_CLOCK_LT(RTIMER_NOW(),
                 (start + LISTEN_TIME_AFTER_PACKET_DETECTED))) {
          powercycle_turn_radio_off();
        }
      }
    }

    if(RTIMER_CLOCK_LT(RTIMER_NOW() - cycle_start, CYCLE_TIME - CHECK_TIME * 4)) {
      /* Schedule the next powercycle interrupt, or sleep the mcu
	 until then.  Sleeping will not exit from this interrupt, so
	 ensure an occasional wake cycle or foreground processing will
	 be blocked until a packet is detected */
#if RDC_CONF_MCU_SLEEP
      static uint8_t sleepcycle;
      if((sleepcycle++ < 16) && !we_are_sending && !radio_is_on) {
        rtimer_arch_sleep(CYCLE_TIME - (RTIMER_NOW() - cycle_start));
      } else {
        sleepcycle = 0;
        schedule_powercycle_fixed(t, CYCLE_TIME + cycle_start);
        PT_YIELD(&pt);
      }
#else
      schedule_powercycle_fixed(t, CYCLE_TIME + cycle_start);
      PT_YIELD(&pt);
#endif
    }
  }

  PT_END(&pt);
}
/*---------------------------------------------------------------------------*/
static int
broadcast_rate_drop(void)
{
#if CONTIKIMAC_CONF_BROADCAST_RATE_LIMIT
  if(!timer_expired(&broadcast_rate_timer)) {
    broadcast_rate_counter++;
    if(broadcast_rate_counter < CONTIKIMAC_CONF_BROADCAST_RATE_LIMIT) {
      return 0;
    } else {
      return 1;
    }
  } else {
    timer_set(&broadcast_rate_timer, CLOCK_SECOND);
    broadcast_rate_counter = 0;
    return 0;
  }
#else /* CONTIKIMAC_CONF_BROADCAST_RATE_LIMIT */
  return 0;
#endif /* CONTIKIMAC_CONF_BROADCAST_RATE_LIMIT */
}
/*---------------------------------------------------------------------------*/
static int
send_packet(mac_callback_t mac_callback, void *mac_callback_ptr,
	    struct rdc_buf_list *buf_list,
            int is_receiver_awake)
{
  rtimer_clock_t t0;
  rtimer_clock_t encounter_time = 0;
  int strobes;
  uint8_t got_strobe_ack = 0;
  int hdrlen, len;
  uint8_t is_broadcast = 0;
  uint8_t is_reliable = 0;
  uint8_t is_known_receiver = 0;
  uint8_t collisions;
  int transmit_len;
  int ret;
  uint8_t contikimac_was_on;
  uint8_t seqno;
#if WITH_CONTIKIMAC_HEADER
  struct hdr *chdr;
#endif /* WITH_CONTIKIMAC_HEADER */

  /* Exit if RDC and radio were explicitly turned off */
   if(!contikimac_is_on && !contikimac_keep_radio_on) {
    PRINTF("contikimac: radio is turned off\n");
    return MAC_TX_ERR_FATAL;
  }
 
  if(packetbuf_totlen() == 0) {
    PRINTF("contikimac: send_packet data len 0\n");
    return MAC_TX_ERR_FATAL;
  }

#if !NETSTACK_CONF_BRIDGE_MODE
  /* If NETSTACK_CONF_BRIDGE_MODE is set, assume PACKETBUF_ADDR_SENDER is already set. */
  packetbuf_set_addr(PACKETBUF_ADDR_SENDER, &rimeaddr_node_addr);
#endif
  if(rimeaddr_cmp(packetbuf_addr(PACKETBUF_ADDR_RECEIVER), &rimeaddr_null)) {
    is_broadcast = 1;
    PRINTDEBUG("contikimac: send broadcast\n");

    if(broadcast_rate_drop()) {
      return MAC_TX_COLLISION;
    }
  } else {
#if UIP_CONF_IPV6
    PRINTDEBUG("contikimac: send unicast to %02x%02x:%02x%02x:%02x%02x:%02x%02x\n",
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[0],
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[1],
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[2],
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[3],
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[4],
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[5],
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[6],
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[7]);
#else /* UIP_CONF_IPV6 */
    PRINTDEBUG("contikimac: send unicast to %u.%u\n",
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[0],
               packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[1]);
#endif /* UIP_CONF_IPV6 */
  }
  is_reliable = packetbuf_attr(PACKETBUF_ATTR_RELIABLE) ||
    packetbuf_attr(PACKETBUF_ATTR_ERELIABLE);

  packetbuf_set_attr(PACKETBUF_ATTR_MAC_ACK, 1);

#if WITH_CONTIKIMAC_HEADER
  hdrlen = packetbuf_totlen();
  if(packetbuf_hdralloc(sizeof(struct hdr)) == 0) {
    /* Failed to allocate space for contikimac header */
    PRINTF("contikimac: send failed, too large header\n");
    return MAC_TX_ERR_FATAL;
  }
  chdr = packetbuf_hdrptr();
  chdr->id = CONTIKIMAC_ID;
  chdr->len = hdrlen;
  
  /* Create the MAC header for the data packet. */
  hdrlen = NETSTACK_FRAMER.create();
  if(hdrlen < 0) {
    /* Failed to send */
    PRINTF("contikimac: send failed, too large header\n");
    packetbuf_hdr_remove(sizeof(struct hdr));
    return MAC_TX_ERR_FATAL;
  }
  hdrlen += sizeof(struct hdr);
#else
  /* Create the MAC header for the data packet. */
  hdrlen = NETSTACK_FRAMER.create();
  if(hdrlen < 0) {
    /* Failed to send */
    PRINTF("contikimac: send failed, too large header\n");
    return MAC_TX_ERR_FATAL;
  }
#endif

  /* Make sure that the packet is longer or equal to the shortest
     packet length. */
  transmit_len = packetbuf_totlen();
  if(transmit_len < SHORTEST_PACKET_SIZE) {
    /* Pad with zeroes */
    uint8_t *ptr;
    ptr = packetbuf_dataptr();
    memset(ptr + packetbuf_datalen(), 0, SHORTEST_PACKET_SIZE - packetbuf_totlen());

    PRINTF("contikimac: shorter than shortest (%d)\n", packetbuf_totlen());
    transmit_len = SHORTEST_PACKET_SIZE;
  }


  packetbuf_compact();

#ifdef NETSTACK_ENCRYPT
  NETSTACK_ENCRYPT();
#endif /* NETSTACK_ENCRYPT */

  transmit_len = packetbuf_totlen();

  NETSTACK_RADIO.prepare(packetbuf_hdrptr(), transmit_len);

  /* Remove the MAC-layer header since it will be recreated next time around. */
  packetbuf_hdr_remove(hdrlen);

  if(!is_broadcast && !is_receiver_awake) {
#if WITH_PHASE_OPTIMIZATION
    ret = phase_wait(packetbuf_addr(PACKETBUF_ADDR_RECEIVER),
                     CYCLE_TIME, GUARD_TIME,
                     mac_callback, mac_callback_ptr, buf_list);
    if(ret == PHASE_DEFERRED) {
      return MAC_TX_DEFERRED;
    }
    if(ret != PHASE_UNKNOWN) {
      is_known_receiver = 1;
    }
#endif /* WITH_PHASE_OPTIMIZATION */ 
  }
  


  /* By setting we_are_sending to one, we ensure that the rtimer
     powercycle interrupt do not interfere with us sending the packet. */
  we_are_sending = 1;

  /* If we have a pending packet in the radio, we should not send now,
     because we will trash the received packet. Instead, we signal
     that we have a collision, which lets the packet be received. This
     packet will be retransmitted later by the MAC protocol
     instread. */
  if(NETSTACK_RADIO.receiving_packet() || NETSTACK_RADIO.pending_packet()) {
    we_are_sending = 0;
    PRINTF("contikimac: collision receiving %d, pending %d\n",
           NETSTACK_RADIO.receiving_packet(), NETSTACK_RADIO.pending_packet());
    return MAC_TX_COLLISION;
  }
  
  /* Switch off the radio to ensure that we didn't start sending while
     the radio was doing a channel check. */
  off();


  strobes = 0;

  /* Send a train of strobes until the receiver answers with an ACK. */
  collisions = 0;

  got_strobe_ack = 0;

  /* Set contikimac_is_on to one to allow the on() and off() functions
     to control the radio. We restore the old value of
     contikimac_is_on when we are done. */
  contikimac_was_on = contikimac_is_on;
  contikimac_is_on = 1;

#if !RDC_CONF_HARDWARE_CSMA
    /* Check if there are any transmissions by others. */
    /* TODO: why does this give collisions before sending with the mc1322x? */
  if(is_receiver_awake == 0) {
    int i;
    for(i = 0; i < CCA_COUNT_MAX_TX; ++i) {
      t0 = RTIMER_NOW();
      on();
#if CCA_CHECK_TIME > 0
      while(RTIMER_CLOCK_LT(RTIMER_NOW(), t0 + CCA_CHECK_TIME)) { }
#endif
      if(NETSTACK_RADIO.channel_clear() == 0) {
        collisions++;
        off();
        break;
      }
      off();
      t0 = RTIMER_NOW();
      while(RTIMER_CLOCK_LT(RTIMER_NOW(), t0 + CCA_SLEEP_TIME)) { }
    }
  }

  if(collisions > 0) {
    we_are_sending = 0;
    off();
    PRINTF("contikimac: collisions before sending\n");
    contikimac_is_on = contikimac_was_on;
    return MAC_TX_COLLISION;
  }
#endif /* RDC_CONF_HARDWARE_CSMA */

#if !RDC_CONF_HARDWARE_ACK
  if(!is_broadcast) {
    /* Turn radio on to receive expected unicast ack.  Not necessary
       with hardware ack detection, and may trigger an unnecessary cca
       or rx cycle */
     on();
  }
#endif

  watchdog_periodic();
  t0 = RTIMER_NOW();
  seqno = packetbuf_attr(PACKETBUF_ATTR_MAC_SEQNO);
  for(strobes = 0, collisions = 0;
      got_strobe_ack == 0 && collisions == 0 &&
      RTIMER_CLOCK_LT(RTIMER_NOW(), t0 + STROBE_TIME); strobes++) {

    watchdog_periodic();

    if(!is_broadcast && (is_receiver_awake || is_known_receiver) &&
       !RTIMER_CLOCK_LT(RTIMER_NOW(), t0 + MAX_PHASE_STROBE_TIME)) {
      PRINTF("miss to %d\n", packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[0]);
      break;
    }

    len = 0;

    {
      rtimer_clock_t wt;
      rtimer_clock_t txtime;
      int ret;

      txtime = RTIMER_NOW();
      ret = NETSTACK_RADIO.transmit(transmit_len);

#if RDC_CONF_HARDWARE_ACK
     /* For radios that block in the transmit routine and detect the
	ACK in hardware */
      if(ret == RADIO_TX_OK) {
        if(!is_broadcast) {
          got_strobe_ack = 1;
          encounter_time = txtime;
          break;
        }
      } else if (ret == RADIO_TX_NOACK) {
      } else if (ret == RADIO_TX_COLLISION) {
          PRINTF("contikimac: collisions while sending\n");
          collisions++;
      }
      wt = RTIMER_NOW();
      while(RTIMER_CLOCK_LT(RTIMER_NOW(), wt + INTER_PACKET_INTERVAL)) { }
#else /* RDC_CONF_HARDWARE_ACK */
     /* Wait for the ACK packet */
      wt = RTIMER_NOW();
      while(RTIMER_CLOCK_LT(RTIMER_NOW(), wt + INTER_PACKET_INTERVAL)) { }

      if(!is_broadcast && (NETSTACK_RADIO.receiving_packet() ||
                           NETSTACK_RADIO.pending_packet() ||
                           NETSTACK_RADIO.channel_clear() == 0)) {
        uint8_t ackbuf[ACK_LEN];
        wt = RTIMER_NOW();
        while(RTIMER_CLOCK_LT(RTIMER_NOW(), wt + AFTER_ACK_DETECTECT_WAIT_TIME)) { }

        len = NETSTACK_RADIO.read(ackbuf, ACK_LEN);
        //PRINTF("%u %u vs %u", len, ackbuf[ACK_LEN - 1], seqno);
        if(len == ACK_LEN && seqno == ackbuf[ACK_LEN - 1]) {
          got_strobe_ack = 1;
          encounter_time = txtime;
          break;
        } else {
          PRINTF("contikimac: collisions while sending\n");
          collisions++;
        }
      }
#endif /* RDC_CONF_HARDWARE_ACK */
    }
  }

  off();

  PRINTF("contikimac: send (strobes=%u, len=%u, %s, %s), done\n", strobes,
         packetbuf_totlen(),
         got_strobe_ack ? "ack" : "no ack",
         collisions ? "collision" : "no collision");

#if CONTIKIMAC_CONF_COMPOWER
  /* Accumulate the power consumption for the packet transmission. */
  compower_accumulate(&current_packet);

  /* Convert the accumulated power consumption for the transmitted
     packet to packet attributes so that the higher levels can keep
     track of the amount of energy spent on transmitting the
     packet. */
  compower_attrconv(&current_packet);

  /* Clear the accumulated power consumption so that it is ready for
     the next packet. */
  compower_clear(&current_packet);
#endif /* CONTIKIMAC_CONF_COMPOWER */

  contikimac_is_on = contikimac_was_on;
  we_are_sending = 0;

  /* Determine the return value that we will return from the
     function. We must pass this value to the phase module before we
     return from the function.  */
  if(collisions > 0) {
    ret = MAC_TX_COLLISION;
  } else if(!is_broadcast && !got_strobe_ack) {
    ret = MAC_TX_NOACK;
  } else {
    ret = MAC_TX_OK;
  }

#if WITH_PHASE_OPTIMIZATION
  if(is_known_receiver && got_strobe_ack) {
    PRINTF("no miss %d wake-ups %d\n",
	   packetbuf_addr(PACKETBUF_ADDR_RECEIVER)->u8[0],
           strobes);
  }

  if(!is_broadcast) {
    if(collisions == 0 && is_receiver_awake == 0) {
      phase_update(packetbuf_addr(PACKETBUF_ADDR_RECEIVER),
		   encounter_time, ret);
    }
  }
#endif /* WITH_PHASE_OPTIMIZATION */

  return ret;
}
/*---------------------------------------------------------------------------*/
static void
qsend_packet(mac_callback_t sent, void *ptr)
{
  int ret = send_packet(sent, ptr, NULL, 0);
  if(ret != MAC_TX_DEFERRED) {
    mac_call_sent_callback(sent, ptr, ret, 1);
  }
}