5eb4a0fe8d
computed only over the actual samples, not over the entire buffer. Also, the initial link estimate is much more conservative now (16 transmissions) to favor links that have been probed, and which therefore are likely to have better ETXs.
149 lines
4.7 KiB
C
149 lines
4.7 KiB
C
/**
|
|
* \addtogroup rimelinkestimate
|
|
* @{
|
|
*/
|
|
/*
|
|
* Copyright (c) 2010, Swedish Institute of Computer Science.
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. Neither the name of the Institute nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* This file is part of the Contiki operating system.
|
|
*
|
|
* $Id: collect-link-estimate.c,v 1.5 2010/10/11 23:34:02 adamdunkels Exp $
|
|
*/
|
|
|
|
/**
|
|
* \file
|
|
* Implementation of Collect link estimate based on ETX
|
|
* \author
|
|
* Adam Dunkels <adam@sics.se>
|
|
*/
|
|
|
|
#include "net/rime/collect.h"
|
|
#include "net/rime/collect-link-estimate.h"
|
|
|
|
/* This defines the window used by the ETX computation when computing
|
|
the ETX. It cannot be larger than
|
|
COLLECT_LINK_ESTIMATE_HISTORY_SIZE, which is defined in
|
|
collect-link-estimate.h. */
|
|
#define ETX_HISTORY_WINDOW 8
|
|
|
|
#define INITIAL_LINK_ESTIMATE 16
|
|
|
|
#define DEBUG 0
|
|
#if DEBUG
|
|
#include <stdio.h>
|
|
#define PRINTF(...) printf(__VA_ARGS__)
|
|
#else
|
|
#define PRINTF(...)
|
|
#endif
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
static void
|
|
set_all_estimates(struct collect_link_estimate *le, uint16_t value)
|
|
{
|
|
int i;
|
|
|
|
for(i = 0; i < ETX_HISTORY_WINDOW; i++) {
|
|
le->history[i] = value;
|
|
}
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
void
|
|
collect_link_estimate_new(struct collect_link_estimate *le)
|
|
{
|
|
/* Start with a conservative / pessimistic estimate of link quality
|
|
for new links. */
|
|
set_all_estimates(le, 0/*INITIAL_LINK_ESTIMATE*/);
|
|
le->historyptr = 0;
|
|
le->num_estimates = 0;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
void
|
|
collect_link_estimate_update_tx(struct collect_link_estimate *le, uint8_t tx)
|
|
{
|
|
if(tx == 0) {
|
|
/* printf("ERROR tx == 0\n");*/
|
|
return;
|
|
}
|
|
if(le != NULL) {
|
|
/* if(le->num_estimates == 0) {
|
|
set_all_estimates(le, tx);
|
|
} else*/ {
|
|
le->history[le->historyptr] = tx;
|
|
le->historyptr = (le->historyptr + 1) % ETX_HISTORY_WINDOW;
|
|
}
|
|
if(le->num_estimates < ETX_HISTORY_WINDOW) {
|
|
le->num_estimates++;
|
|
}
|
|
}
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
void
|
|
collect_link_estimate_update_tx_fail(struct collect_link_estimate *le,
|
|
uint8_t tx)
|
|
{
|
|
collect_link_estimate_update_tx(le, tx * 2);
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
void
|
|
collect_link_estimate_update_rx(struct collect_link_estimate *n)
|
|
{
|
|
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
uint16_t
|
|
collect_link_estimate(struct collect_link_estimate *le)
|
|
{
|
|
int i;
|
|
uint16_t etx;
|
|
|
|
if(le->num_estimates == 0) {
|
|
return INITIAL_LINK_ESTIMATE * COLLECT_LINK_ESTIMATE_UNIT;
|
|
}
|
|
|
|
PRINTF("collect_link_estimate: ");
|
|
etx = 0;
|
|
for(i = 0; i < le->num_estimates; ++i) {
|
|
PRINTF("%d+", le->history[i]);
|
|
etx += le->history[(le->historyptr - i - 1) & (ETX_HISTORY_WINDOW - 1)];
|
|
}
|
|
PRINTF("/%d = %d\n", i,
|
|
(COLLECT_LINK_ESTIMATE_UNIT * etx) / i);
|
|
return (COLLECT_LINK_ESTIMATE_UNIT * etx) / i;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
int
|
|
collect_link_estimate_num_estimates(struct collect_link_estimate *le)
|
|
{
|
|
if(le != NULL) {
|
|
return le->num_estimates;
|
|
}
|
|
return 0;
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
/** @} */
|