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Updated to the minrank-hysteresis OF

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Nicolas Tsiftes 2011-02-04 15:45:24 +01:00 committed by nvt
parent 0b23116c30
commit e3638d2791
1 changed files with 38 additions and 21 deletions
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59
core/net/rpl/rpl-of-etx.c
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@ -36,7 +36,10 @@
*/ */
/** /**
* \file * \file
* An implementation of RPL's objective function 1 (ETX). * The minrank-hysteresis objective function (OCP 1).
*
* This implementation uses the estimated number of
* transmissions (ETX) as the additive routing metric.
* *
* \author Joakim Eriksson <joakime@sics.se>, Nicolas Tsiftes <nvt@sics.se> * \author Joakim Eriksson <joakime@sics.se>, Nicolas Tsiftes <nvt@sics.se>
*/ */
@ -60,21 +63,30 @@ rpl_of_t rpl_of_etx = {
1 1
}; };
#define LINK_ETX_MIN 1 /* Reject parents that have a higher link metric than the following. */
#define LINK_ETX_MAX 10 #define MAX_LINK_METRIC 10
#define LINK_ETX_GUESS 3
#define PATH_ETX_MIN 1
#define PATH_ETX_MAX 200
#define PARENT_SWITCH_ETX_THRESHOLD 0.5
typedef uint16_t etx_t; /* Reject parents that have a higher path cost than the following. */
#define MAX_PATH_COST 100
static etx_t min_path_etx = INFINITE_RANK; /* An initial guess of the link metric. */
#define INITIAL_LINK_METRIC 3
/*
* The rank must differ more than 1/PARENT_SWITCH_THRESHOLD_DIV in order
* to switch preferred parent.
*/
#define PARENT_SWITCH_THRESHOLD_DIV 2
#define MAX_DIFFERENCE(dag) \
((dag)->min_hoprankinc / PARENT_SWITCH_THRESHOLD_DIV)
static rpl_rank_t min_path_cost = INFINITE_RANK;
static void static void
reset(void *dag) reset(void *dag)
{ {
min_path_etx = INFINITE_RANK; min_path_cost = INFINITE_RANK;
} }
static void static void
@ -87,7 +99,7 @@ parent_state_callback(rpl_parent_t *parent, int known, int etx)
if(!known) { if(!known) {
if(RPL_PARENT_COUNT(dag) == 1) { if(RPL_PARENT_COUNT(dag) == 1) {
/* Our last parent has disappeared, set the path ETX to INFINITE_RANK. */ /* Our last parent has disappeared, set the path ETX to INFINITE_RANK. */
min_path_etx = INFINITE_RANK; min_path_cost = INFINITE_RANK;
} }
} }
} }
@ -103,11 +115,11 @@ calculate_rank(rpl_parent_t *p, rpl_rank_t base_rank)
if(base_rank == 0) { if(base_rank == 0) {
return INFINITE_RANK; return INFINITE_RANK;
} }
rank_increase = LINK_ETX_GUESS * DEFAULT_MIN_HOPRANKINC; rank_increase = INITIAL_LINK_METRIC * DEFAULT_MIN_HOPRANKINC;
} else { } else {
dag = (rpl_dag_t *)p->dag; dag = (rpl_dag_t *)p->dag;
if(p->local_confidence == 0) { if(p->local_confidence == 0) {
p->local_confidence = LINK_ETX_GUESS * ETX_DIVISOR; p->local_confidence = INITIAL_LINK_METRIC * ETX_DIVISOR;
} }
rank_increase = (p->local_confidence * dag->min_hoprankinc) / ETX_DIVISOR; rank_increase = (p->local_confidence * dag->min_hoprankinc) / ETX_DIVISOR;
if(base_rank == 0) { if(base_rank == 0) {
@ -115,12 +127,12 @@ calculate_rank(rpl_parent_t *p, rpl_rank_t base_rank)
} }
} }
PRINTF("RPL: OF1 calculate rank, base rank = %u, rank_increase = %u\n", PRINTF("RPL: MRHOF calculate rank, base rank = %u, rank_increase = %u\n",
(unsigned)base_rank, rank_increase); (unsigned)base_rank, rank_increase);
if(base_rank < min_path_etx) { if(base_rank < min_path_cost) {
min_path_etx = base_rank; min_path_cost = base_rank;
PRINTF("RPL: min_path_etx updated to %u\n", min_path_etx); PRINTF("RPL: min_path_cost updated to %u\n", min_path_cost);
} }
if(INFINITE_RANK - base_rank < rank_increase) { if(INFINITE_RANK - base_rank < rank_increase) {
@ -132,7 +144,7 @@ calculate_rank(rpl_parent_t *p, rpl_rank_t base_rank)
new_rank = base_rank + rank_increase; new_rank = base_rank + rank_increase;
} }
PRINTF("RPL: Path ETX %u\n", (unsigned)new_rank); PRINTF("RPL: Path cost %u\n", (unsigned)new_rank);
return new_rank; return new_rank;
} }
@ -146,11 +158,16 @@ best_parent(rpl_parent_t *p1, rpl_parent_t *p2)
dag = (rpl_dag_t *)p1->dag; /* Both parents must be in the same DAG. */ dag = (rpl_dag_t *)p1->dag; /* Both parents must be in the same DAG. */
p1_rank = DAG_RANK(calculate_rank(p1, 0), dag); p1_rank = calculate_rank(p1, 0);
p2_rank = DAG_RANK(calculate_rank(p2, 0), dag); p2_rank = calculate_rank(p2, 0);
/* Maintain stability of the preferred parent in case of similar ranks. */ /* Maintain stability of the preferred parent in case of similar ranks. */
if(p1_rank == p2_rank) { if(p1_rank < p2_rank + MAX_DIFFERENCE(dag) &&
p1_rank > p2_rank - MAX_DIFFERENCE(dag)) {
PRINTF("RPL: MRHOF hysteresis: %u <= %u <= %u\n",
p2_rank - MAX_DIFFERENCE(dag),
p1_rank,
p2_rank + MAX_DIFFERENCE(dag));
if(p1 == dag->preferred_parent) { if(p1 == dag->preferred_parent) {
return p1; return p1;
} else if(p2 == dag->preferred_parent) { } else if(p2 == dag->preferred_parent) {