void etx_update(etx_neighbor_t *candidate)
{
DEBUG("update!\n");
/*
* Update the current ETX value of a candidate
*/
double d_f;
double d_r;
if (reached_window != 1 || candidate == NULL) {
//We will wait at least ETX_WINDOW beacons until we decide to
//calculate an ETX value, so that we have a good estimate
return;
}
/*
* Calculate d_f (the forward PDR) from ME to this candidate.
*/
d_f = candidate->packets_rx / (double) ETX_WINDOW;
/*
* Calculate d_r (the backwards PDR) from this candidate to ME
*/
d_r = etx_count_packet_tx(candidate) / (double) ETX_WINDOW;
/*
* Calculate the current ETX value for my link to this candidate.
*/
if (d_f * d_r != 0) {
candidate->cur_etx = 1 / (d_f * d_r);
}
else {
candidate->cur_etx = 0;
}
DEBUG(
"Estimated ETX Metric is %f for candidate w/ addr %d\n"
"Estimated PDR_forward is %f\n"
"Estimated PDR_backwrd is %f\n"
"\n"
"Received Packets: %d\n"
"Sent Packets : %d\n\n",
candidate->cur_etx, candidate->addr.uint8[ETX_IPV6_LAST_BYTE],
d_f, d_r, candidate->packets_rx, etx_count_packet_tx(candidate));
}
static void *etx_beacon(void *arg)
{
(void) arg;
/*
* Sends a message every ETX_INTERVAL +/- a jitter-value (default is 10%) .
* A correcting variable is needed to stay at a base interval of
* ETX_INTERVAL between the wakeups. It takes the old jittervalue in account
* and modifies the time to wait accordingly.
*/
etx_probe_t *packet = etx_get_send_buf();
uint8_t p_length = 0;
while (true) {
thread_sleep();
mutex_lock(&etx_mutex);
//Build etx packet
p_length = 0;
for (uint8_t i = 0; i < ETX_BEST_CANDIDATES; i++) {
if (candidates[i].used != 0) {
packet->data[i * ETX_TUPLE_SIZE] =
candidates[i].addr.uint8[ETX_IPV6_LAST_BYTE];
packet->data[i * ETX_TUPLE_SIZE + ETX_PKT_REC_OFFSET] =
etx_count_packet_tx(&candidates[i]);
p_length = p_length + ETX_PKT_HDR_LEN;
}
}
packet->length = p_length;
/* will be send broadcast, so if_id and destination address will be
* ignored (see documentation)
*/
sixlowpan_mac_send_ieee802154_frame(0, NULL, 8, &etx_send_buf[0],
ETX_DATA_MAXLEN + ETX_PKT_HDR_LEN, 1);
DEBUG("sent beacon!\n");
etx_set_packets_received();
cur_round++;
if (cur_round == ETX_WINDOW) {
if (reached_window != 1) {
//first round is through
reached_window = 1;
}
cur_round = 0;
}
mutex_unlock(&etx_mutex);
}
return NULL;
}
double etx_get_metric(ipv6_addr_t * address) {
etx_neighbor_t * candidate = etx_find_candidate(address);
if (candidate != NULL ) {
if (etx_count_packet_tx(candidate) > 0) {
//this means the current etx_value is not outdated
return candidate->cur_etx;
} else {
//The last time I received a packet is too long ago to give a
//good estimate of the etx value
return 0;
}
}
return 0;
}
void etx_beacon(void) {
/*
* Sends a message every ETX_INTERVAL +/- a jitter-value (default is 10%) .
* A correcting variable is needed to stay at a base interval of
* ETX_INTERVAL between the wakeups. It takes the old jittervalue in account
* and modifies the time to wait accordingly.
*/
etx_probe_t * packet = etx_get_send_buf();
uint8_t p_length = 0;
/*
* xxx If you get a -Wmissing-braces warning here:
* A -Wmissing-braces warning at this point is a gcc-bug!
* Please delete this information once it's fixed
* See: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53119
*/
ieee_802154_long_t empty_addr = { 0 };
while (true) {
thread_sleep();
mutex_lock(&etx_mutex);
//Build etx packet
p_length = 0;
for (uint8_t i = 0; i < ETX_BEST_CANDIDATES; i++) {
if (candidates[i].used != 0) {
packet->data[i * ETX_TUPLE_SIZE] =
candidates[i].addr.uint8[ETX_IPV6_LAST_BYTE];
packet->data[i * ETX_TUPLE_SIZE + ETX_PKT_REC_OFFSET] =
etx_count_packet_tx(&candidates[i]);
p_length = p_length + ETX_PKT_HDR_LEN;
}
}
packet->length = p_length;
send_ieee802154_frame(&empty_addr, &etx_send_buf[0],
ETX_DATA_MAXLEN+ETX_PKT_HDR_LEN, 1);
DEBUG("sent beacon!\n");
etx_set_packets_received();
cur_round++;
if (cur_round == ETX_WINDOW) {
if (reached_window != 1) {
//first round is through
reached_window = 1;
}
cur_round = 0;
}
mutex_unlock(&etx_mutex,0);
}
}
void show_candidates(void) {
etx_neighbor_t * candidate;
etx_neighbor_t *end;
for (candidate = &candidates[0], end = candidates
+ ETX_MAX_CANDIDATE_NEIGHBORS; candidate < end;
candidate++) {
if (candidate->used == 0) {
break;
}
printf("Candidates Addr:%d\n"
"\t cur_etx:%f\n"
"\t packets_rx:%d\n"
"\t packets_tx:%d\n"
"\t used:%d\n", candidate->addr.uint8[ETX_IPV6_LAST_BYTE],
candidate->cur_etx, candidate->packets_rx,
etx_count_packet_tx(candidate),
candidate->used);
}
}
