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Improved detection of link-layer ACKs; increased the time ContikiMAC waits when it has detected a link-layer ACK; increased the number of silence periods required to detect a CCA false positive

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This commit is contained in:
adamdunkels 2010-02-28 08:33:21 +00:00
parent fa1a96636e
commit ed88f487c8
1 changed files with 22 additions and 15 deletions
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37
core/net/mac/contikimac.c
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@ -28,7 +28,7 @@
*
* This file is part of the Contiki operating system.
*
* $Id: contikimac.c,v 1.5 2010/02/23 20:09:11 nifi Exp $
* $Id: contikimac.c,v 1.6 2010/02/28 08:33:21 adamdunkels Exp $
*/
/**
@ -106,7 +106,7 @@ struct announcement_msg {
#define LISTEN_TIME (RTIMER_ARCH_SECOND / 150)
#define WAIT_TIME_BEFORE_STROBE_ACK_CCA RTIMER_ARCH_SECOND / 3000
#define WAIT_TIME_AFTER_STROBE_ACK_CCA RTIMER_ARCH_SECOND / 2000
#define WAIT_TIME_AFTER_STROBE_ACK_CCA RTIMER_ARCH_SECOND / 1500
/* The cycle time for announcements. */
#define ANNOUNCEMENT_PERIOD 4 * CLOCK_SECOND
@ -209,6 +209,10 @@ schedule_powercycle(struct rtimer *t, rtimer_clock_t time)
if(contikimac_is_on) {
if(RTIMER_CLOCK_LT(RTIMER_TIME(t) + time, RTIMER_NOW())) {
time = RTIMER_NOW() - RTIMER_TIME(t);
}
while(RTIMER_TIME(t) + time == RTIMER_NOW() ||
RTIMER_TIME(t) + time == RTIMER_NOW() + 1) {
++time;
@ -316,7 +320,7 @@ powercycle(struct rtimer *t, void *ptr)
if(NETSTACK_RADIO.receiving_packet()) {
silence_periods = 0;
}
if(silence_periods > 2) {
if(silence_periods > 3) {
leds_on(LEDS_RED);
powercycle_turn_radio_off();
#if CONTIKIMAC_CONF_COMPOWER
@ -358,7 +362,7 @@ powercycle(struct rtimer *t, void *ptr)
compower_accumulate(&compower_idle_activity);
#endif /* CONTIKIMAC_CONF_COMPOWER */
}
break_the_loop:
/* If the packet indication flag is still set, it means that
there was never a packet received by the radio. We increase
the packet_indicated_but_not_received counter. */
@ -530,6 +534,8 @@ send_packet(void)
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;
}
@ -618,7 +624,9 @@ send_packet(void)
while(RTIMER_CLOCK_LT
(RTIMER_NOW(), wt + WAIT_TIME_BEFORE_STROBE_ACK_CCA)) { }
#endif
if(!is_broadcast && !NETSTACK_RADIO.channel_clear()) {
if(!is_broadcast && (NETSTACK_RADIO.receiving_packet() ||
NETSTACK_RADIO.pending_packet() ||
NETSTACK_RADIO.channel_clear() == 0)) {
uint8_t ackbuf[ACK_LEN];
wt = RTIMER_NOW();
#if NURTIMER
@ -628,18 +636,16 @@ send_packet(void)
while(RTIMER_CLOCK_LT
(RTIMER_NOW(), wt + WAIT_TIME_AFTER_STROBE_ACK_CCA)) { }
#endif
if(!is_broadcast) {
len = NETSTACK_RADIO.read(ackbuf, ACK_LEN);
if(len == ACK_LEN) {
got_strobe_ack = 1;
encounter_time = now;
packet_indication_flag = 0;
} else if(len > 0) {
packet_indication_flag = 0;
collisions++;
}
len = NETSTACK_RADIO.read(ackbuf, ACK_LEN);
if(len == ACK_LEN) {
got_strobe_ack = 1;
encounter_time = now;
packet_indication_flag = 0;
} else {
packet_indication_flag = 0;
collisions++;
}
} else {
}
}
}
@ -911,5 +917,6 @@ contikimac_debug_print(void)
indicated_last = indicated;
clear_second_last = clear_second;
clear_third_last = clear_third;
return 0;
}
/*---------------------------------------------------------------------------*/