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Simplified. Removed the need for an initial guess.

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This commit is contained in:
Nicolas Tsiftes 2011-03-16 13:26:52 +01:00
parent 6554e87c00
commit eee9a68b12
1 changed files with 13 additions and 20 deletions
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33
core/net/neighbor-info.c
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@ -46,9 +46,7 @@
#define ETX_LIMIT 15
#define ETX_SCALE 100
#define ETX_ALPHA 90
#define ETX_FIRST_GUESS 5
#define NOACK_PACKET_ETX 8
#define ETX_NOACK_PENALTY ETX_LIMIT
/*---------------------------------------------------------------------------*/
NEIGHBOR_ATTRIBUTE(uint8_t, etx, NULL);
@ -61,16 +59,17 @@ update_etx(const rimeaddr_t *dest, int packet_etx)
uint8_t recorded_etx, new_etx;
etxp = (uint8_t *)neighbor_attr_get_data(&etx, dest);
packet_etx = NEIGHBOR_INFO_ETX2FIX(packet_etx);
if(etxp == NULL || *etxp == 0) {
recorded_etx = NEIGHBOR_INFO_ETX2FIX(ETX_FIRST_GUESS);
recorded_etx = NEIGHBOR_INFO_ETX2FIX(ETX_LIMIT);
new_etx = packet_etx;
} else {
recorded_etx = *etxp;
/* Update the EWMA of the ETX for the neighbor. */
new_etx = ((uint16_t)recorded_etx * ETX_ALPHA +
(uint16_t)packet_etx * (ETX_SCALE - ETX_ALPHA)) / ETX_SCALE;
}
/* Update the EWMA of the ETX for the neighbor. */
packet_etx = NEIGHBOR_INFO_ETX2FIX(packet_etx);
new_etx = ((uint16_t)recorded_etx * ETX_ALPHA +
(uint16_t)packet_etx * (ETX_SCALE - ETX_ALPHA)) / ETX_SCALE;
PRINTF("neighbor-info: ETX changed from %d to %d (packet ETX = %d) %d\n",
NEIGHBOR_INFO_FIX2ETX(recorded_etx),
NEIGHBOR_INFO_FIX2ETX(new_etx),
@ -96,9 +95,6 @@ add_neighbor(const rimeaddr_t *addr)
PRINTF("neighbor-info: The neighbor is already known\n");
break;
default:
if(subscriber_callback != NULL) {
subscriber_callback(addr, 1, NEIGHBOR_INFO_ETX2FIX(ETX_FIRST_GUESS));
}
break;
}
}
@ -127,18 +123,15 @@ neighbor_info_packet_sent(int status, int numtx)
packet_etx = numtx;
break;
case MAC_TX_NOACK:
packet_etx = NOACK_PACKET_ETX;
/* error and collissions will not cause high hits ??? */
packet_etx = ETX_NOACK_PENALTY;
break;
case MAC_TX_ERR:
default:
packet_etx = 0;
break;
/* Do not penalize the ETX when collisions or transmission
errors occur. */
return;
}
if(packet_etx > 0) {
update_etx(dest, packet_etx);
}
update_etx(dest, packet_etx);
}
/*---------------------------------------------------------------------------*/
void
@ -175,6 +168,6 @@ neighbor_info_get_etx(const rimeaddr_t *addr)
uint8_t *etxp;
etxp = (uint8_t *)neighbor_attr_get_data(&etx, addr);
return etxp == NULL ? 0 : *etxp;
return etxp == NULL ? ETX_LIMIT : *etxp;
}
/*---------------------------------------------------------------------------*/