X-Git-Url: https://oss.titaniummirror.com/gitweb/?p=tinyos-2.x.git;a=blobdiff_plain;f=tos%2Flib%2Fnet%2F4bitle%2FLinkEstimatorP.nc;h=d1cb1af8c22fd2b6207d1400f4fe4864b53aae71;hp=6738a9f8e6093af01c2b2d12f8f81d0aa81c1c1c;hb=ce7b4e8d571680f9aca097275fbee3eac5a22227;hpb=223d6e27fdc1a8865531c24a2d05e01a032c98a9 diff --git a/tos/lib/net/4bitle/LinkEstimatorP.nc b/tos/lib/net/4bitle/LinkEstimatorP.nc index 6738a9f8..d1cb1af8 100644 --- a/tos/lib/net/4bitle/LinkEstimatorP.nc +++ b/tos/lib/net/4bitle/LinkEstimatorP.nc @@ -29,7 +29,7 @@ @ Created: April 24, 2006 */ -#include "LinkEstimator.h" +#include "./LinkEstimator.h" module LinkEstimatorP { provides { @@ -56,18 +56,18 @@ implementation { // configure the link estimator and some constants enum { - // If the eetx estimate is below this threshold + // If the etx estimate is below this threshold // do not evict a link - EVICT_EETX_THRESHOLD = 55, + EVICT_ETX_THRESHOLD = 65, // if received sequence number if larger than the last sequence // number by this gap, we reinitialize the link MAX_PKT_GAP = 10, - BEST_EETX = 0, + BEST_ETX = 10, INVALID_RVAL = 0xff, INVALID_NEIGHBOR_ADDR = 0xff, // if we don't know the link quality, we need to return a value so // large that it will not be used to form paths - VERY_LARGE_EETX_VALUE = 0xff, + VERY_LARGE_ETX_VALUE = 0xffff, // decay the link estimate using this alpha // we use a denominator of 10, so this corresponds to 0.2 ALPHA = 9, @@ -77,10 +77,10 @@ implementation { // number of beacons to wait before computing a new // BLQ (Beacon-driven Link Quality) BLQ_PKT_WINDOW = 3, - // largest EETX value that we feed into the link quality EWMA - // a value of 60 corresponds to having to make six transmissions + // largest ETX value that we feed into the link quality EWMA + // a value of 70 corresponds to having to make six transmissions // to successfully receive one acknowledgement - LARGE_EETX_VALUE = 60 + LARGE_ETX_VALUE = 70 }; // keep information about links from the neighbors @@ -169,7 +169,7 @@ implementation { ne->failcnt = 0; ne->flags = (INIT_ENTRY | VALID_ENTRY); ne->inquality = 0; - ne->eetx = 0; + ne->etx = 0; } // find the index to the entry for neighbor ll_addr @@ -199,12 +199,12 @@ implementation { // find the index to the worst neighbor if the eetx // estimate is greater than the given threshold - uint8_t findWorstNeighborIdx(uint8_t thresholdEETX) { + uint8_t findWorstNeighborIdx(uint8_t thresholdETX) { uint8_t i, worstNeighborIdx; - uint16_t worstEETX, thisEETX; + uint16_t worstETX, thisETX; worstNeighborIdx = INVALID_RVAL; - worstEETX = 0; + worstETX = 0; for (i = 0; i < NEIGHBOR_TABLE_SIZE; i++) { if (!(NeighborTable[i].flags & VALID_ENTRY)) { dbg("LI", "Invalid so continuing\n"); @@ -218,13 +218,13 @@ implementation { dbg("LI", "Pinned entry, so continuing\n"); continue; } - thisEETX = NeighborTable[i].eetx; - if (thisEETX >= worstEETX) { + thisETX = NeighborTable[i].etx; + if (thisETX >= worstETX) { worstNeighborIdx = i; - worstEETX = thisEETX; + worstETX = thisETX; } } - if (worstEETX >= thresholdEETX) { + if (worstETX >= thresholdETX) { return worstNeighborIdx; } else { return INVALID_RVAL; @@ -269,45 +269,44 @@ implementation { } - // update the EETX estimator + // update the ETX estimator // called when new beacon estimate is done // also called when new DEETX estimate is done - void updateEETX(neighbor_table_entry_t *ne, uint16_t newEst) { - ne->eetx = (ALPHA * ne->eetx + (10 - ALPHA) * newEst + 5)/10; + void updateETX(neighbor_table_entry_t *ne, uint16_t newEst) { + ne->etx = (ALPHA * ne->etx + (10 - ALPHA) * newEst)/10; } - // update data driven EETX - void updateDEETX(neighbor_table_entry_t *ne) { + // update data driven ETX + void updateDETX(neighbor_table_entry_t *ne) { uint16_t estETX; if (ne->data_success == 0) { // if there were no successful packet transmission in the // last window, our current estimate is the number of failed // transmissions - estETX = (ne->data_total - 1)* 10; + estETX = ne->data_total * 10; } else { - estETX = (10 * ne->data_total) / ne->data_success - 10; + estETX = (10 * ne->data_total) / ne->data_success; ne->data_success = 0; ne->data_total = 0; } - updateEETX(ne, estETX); + updateETX(ne, estETX); } - // EETX (Extra Expected number of Transmission) - // EETX = ETX - 1 - // computeEETX returns EETX*10 - uint8_t computeEETX(uint8_t q1) { + // ETX (Expected number of Transmission) + // computeETX returns ETX*10 + uint16_t computeETX(uint8_t q1) { uint16_t q; if (q1 > 0) { - q = 2550 / q1 - 10; - if (q > 255) { - q = VERY_LARGE_EETX_VALUE; + q = 2500 / q1; + if (q > 250) { + q = VERY_LARGE_ETX_VALUE; } return (uint8_t)q; } else { - return VERY_LARGE_EETX_VALUE; + return VERY_LARGE_ETX_VALUE; } } @@ -335,13 +334,13 @@ implementation { if (totalPkt == 0) { ne->inquality = (ALPHA * ne->inquality) / 10; } else { - newEst = (255 * ne->rcvcnt) / totalPkt; - dbg("LI,LITest", " %hu: %hhu -> %hhu", ne->ll_addr, ne->inquality, (ALPHA * ne->inquality + (10-ALPHA) * newEst + 5)/10); - ne->inquality = (ALPHA * ne->inquality + (10-ALPHA) * newEst + 5)/10; + newEst = (250UL * ne->rcvcnt) / totalPkt; + dbg("LI,LITest", " %hu: %hhu -> %hhu", ne->ll_addr, ne->inquality, (ALPHA * ne->inquality + (10-ALPHA) * newEst)/10); + ne->inquality = (ALPHA * ne->inquality + (10-ALPHA) * newEst)/10; } ne->rcvcnt = 0; ne->failcnt = 0; - updateEETX(ne, computeEETX(ne->inquality)); + updateETX(ne, computeETX(ne->inquality)); } else { dbg("LI", " - entry %i is invalid.\n", (int)i); } @@ -370,16 +369,20 @@ implementation { if (packetGap > 0) { NeighborTable[idx].failcnt += packetGap - 1; } - if (packetGap > MAX_PKT_GAP) { - NeighborTable[idx].failcnt = 0; - NeighborTable[idx].rcvcnt = 1; - NeighborTable[idx].inquality = 0; - } - if (packetGap >= BLQ_PKT_WINDOW) { + // The or with packetGap >= BLQ_PKT_WINDOW is needed in case + // failcnt gets reset above + + if (((NeighborTable[idx].rcvcnt + NeighborTable[idx].failcnt) >= BLQ_PKT_WINDOW) + || (packetGap >= BLQ_PKT_WINDOW)) { updateNeighborTableEst(NeighborTable[idx].ll_addr); } + if (packetGap > MAX_PKT_GAP) { + initNeighborIdx(idx, NeighborTable[idx].ll_addr); + NeighborTable[idx].lastseq = seq; + NeighborTable[idx].rcvcnt = 1; + } } @@ -393,7 +396,7 @@ implementation { if (ne->flags & VALID_ENTRY) { dbg("LI,LITest", "%d:%d inQ=%d, rcv=%d, fail=%d, Q=%d\n", i, ne->ll_addr, ne->inquality, - ne->rcvcnt, ne->failcnt, computeEETX(ne->inquality)); + ne->rcvcnt, ne->failcnt, computeETX(ne->inquality)); } } } @@ -439,12 +442,12 @@ implementation { uint8_t idx; idx = findIdx(neighbor); if (idx == INVALID_RVAL) { - return VERY_LARGE_EETX_VALUE; + return VERY_LARGE_ETX_VALUE; } else { if (NeighborTable[idx].flags & MATURE_ENTRY) { - return NeighborTable[idx].eetx; + return NeighborTable[idx].etx; } else { - return VERY_LARGE_EETX_VALUE; + return VERY_LARGE_ETX_VALUE; } } } @@ -466,7 +469,7 @@ implementation { initNeighborIdx(nidx, neighbor); return SUCCESS; } else { - nidx = findWorstNeighborIdx(BEST_EETX); + nidx = findWorstNeighborIdx(BEST_ETX); if (nidx != INVALID_RVAL) { dbg("LI", "insert: inserted by replacing an entry for neighbor: %d\n", NeighborTable[nidx].ll_addr); @@ -511,7 +514,7 @@ implementation { ne->data_success++; ne->data_total++; if (ne->data_total >= DLQ_PKT_WINDOW) { - updateDEETX(ne); + updateDETX(ne); } return SUCCESS; } @@ -528,7 +531,7 @@ implementation { ne = &NeighborTable[nidx]; ne->data_total++; if (ne->data_total >= DLQ_PKT_WINDOW) { - updateDEETX(ne); + updateDETX(ne); } return SUCCESS; } @@ -623,7 +626,7 @@ implementation { initNeighborIdx(nidx, ll_addr); updateNeighborEntryIdx(nidx, hdr->seq); } else { - nidx = findWorstNeighborIdx(EVICT_EETX_THRESHOLD); + nidx = findWorstNeighborIdx(EVICT_ETX_THRESHOLD); if (nidx != INVALID_RVAL) { dbg("LI", "Evicted neighbor %d at idx %d\n", NeighborTable[nidx].ll_addr, nidx);