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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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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. * 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 LISTEN_TIME (RTIMER_ARCH_SECOND / 150)
#define WAIT_TIME_BEFORE_STROBE_ACK_CCA RTIMER_ARCH_SECOND / 3000 #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. */ /* The cycle time for announcements. */
#define ANNOUNCEMENT_PERIOD 4 * CLOCK_SECOND #define ANNOUNCEMENT_PERIOD 4 * CLOCK_SECOND
@ -209,6 +209,10 @@ schedule_powercycle(struct rtimer *t, rtimer_clock_t time)
if(contikimac_is_on) { 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() || while(RTIMER_TIME(t) + time == RTIMER_NOW() ||
RTIMER_TIME(t) + time == RTIMER_NOW() + 1) { RTIMER_TIME(t) + time == RTIMER_NOW() + 1) {
++time; ++time;
@ -316,7 +320,7 @@ powercycle(struct rtimer *t, void *ptr)
if(NETSTACK_RADIO.receiving_packet()) { if(NETSTACK_RADIO.receiving_packet()) {
silence_periods = 0; silence_periods = 0;
} }
if(silence_periods > 2) { if(silence_periods > 3) {
leds_on(LEDS_RED); leds_on(LEDS_RED);
powercycle_turn_radio_off(); powercycle_turn_radio_off();
#if CONTIKIMAC_CONF_COMPOWER #if CONTIKIMAC_CONF_COMPOWER
@ -358,7 +362,7 @@ powercycle(struct rtimer *t, void *ptr)
compower_accumulate(&compower_idle_activity); compower_accumulate(&compower_idle_activity);
#endif /* CONTIKIMAC_CONF_COMPOWER */ #endif /* CONTIKIMAC_CONF_COMPOWER */
} }
break_the_loop:
/* If the packet indication flag is still set, it means that /* If the packet indication flag is still set, it means that
there was never a packet received by the radio. We increase there was never a packet received by the radio. We increase
the packet_indicated_but_not_received counter. */ the packet_indicated_but_not_received counter. */
@ -530,6 +534,8 @@ send_packet(void)
instread. */ instread. */
if(NETSTACK_RADIO.receiving_packet() || NETSTACK_RADIO.pending_packet()) { if(NETSTACK_RADIO.receiving_packet() || NETSTACK_RADIO.pending_packet()) {
we_are_sending = 0; we_are_sending = 0;
PRINTF("contikimac: collision receiving %d, pending %d\n",
NETSTACK_RADIO.receiving_packet(), NETSTACK_RADIO.pending_packet());
return MAC_TX_COLLISION; return MAC_TX_COLLISION;
} }
@ -618,7 +624,9 @@ send_packet(void)
while(RTIMER_CLOCK_LT while(RTIMER_CLOCK_LT
(RTIMER_NOW(), wt + WAIT_TIME_BEFORE_STROBE_ACK_CCA)) { } (RTIMER_NOW(), wt + WAIT_TIME_BEFORE_STROBE_ACK_CCA)) { }
#endif #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]; uint8_t ackbuf[ACK_LEN];
wt = RTIMER_NOW(); wt = RTIMER_NOW();
#if NURTIMER #if NURTIMER
@ -628,18 +636,16 @@ send_packet(void)
while(RTIMER_CLOCK_LT while(RTIMER_CLOCK_LT
(RTIMER_NOW(), wt + WAIT_TIME_AFTER_STROBE_ACK_CCA)) { } (RTIMER_NOW(), wt + WAIT_TIME_AFTER_STROBE_ACK_CCA)) { }
#endif #endif
if(!is_broadcast) { len = NETSTACK_RADIO.read(ackbuf, ACK_LEN);
len = NETSTACK_RADIO.read(ackbuf, ACK_LEN); if(len == ACK_LEN) {
if(len == ACK_LEN) { got_strobe_ack = 1;
got_strobe_ack = 1; encounter_time = now;
encounter_time = now; packet_indication_flag = 0;
packet_indication_flag = 0;
} else if(len > 0) {
packet_indication_flag = 0;
collisions++;
}
} else { } else {
packet_indication_flag = 0;
collisions++;
} }
} else {
} }
} }
} }
@ -911,5 +917,6 @@ contikimac_debug_print(void)
indicated_last = indicated; indicated_last = indicated;
clear_second_last = clear_second; clear_second_last = clear_second;
clear_third_last = clear_third; clear_third_last = clear_third;
return 0;
} }
/*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/