4bit link estimator

[tinyos-2.x.git] / tos / lib / net / 4bitle / LinkEstimator.h

diff --git a/tos/lib/net/4bitle/LinkEstimator.h b/tos/lib/net/4bitle/LinkEstimator.h
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+/* $Id$ */
+/*
+ * "Copyright (c) 2006 University of Southern California.
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation for any purpose, without fee, and without written
+ * agreement is hereby granted, provided that the above copyright
+ * notice, the following two paragraphs and the author appear in all
+ * copies of this software.
+ *
+ * IN NO EVENT SHALL THE UNIVERSITY OF SOUTHERN CALIFORNIA BE LIABLE TO
+ * ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
+ * DAMAGES ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
+ * DOCUMENTATION, EVEN IF THE UNIVERSITY OF SOUTHERN CALIFORNIA HAS BEEN
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THE UNIVERSITY OF SOUTHERN CALIFORNIA SPECIFICALLY DISCLAIMS ANY
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE
+ * PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
+ * SOUTHERN CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE,
+ * SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS."
+ *
+ */
+
+#ifndef LINK_ESITIMATOR_H
+#define LINK_ESITIMATOR_H
+/*
+ @ author Omprakash Gnawali
+ @ Created: June 08, 2006
+ */
+
+// Number of entries in the neighbor table
+#define NEIGHBOR_TABLE_SIZE 10
+
+// Masks for the flag field in the link estimation header
+enum {
+  // use last four bits to keep track of
+  // how many footer entries there are
+  NUM_ENTRIES_FLAG = 15,
+};
+
+// The first byte of each outgoing packet is a control byte
+// Bits 4..7 reserved for routing and other protocols
+// Bits 0..3 is used by the link estimator to encode the
+//   number of linkest entries in the packet
+
+// link estimator header added to
+// every message passing through the link estimator
+typedef nx_struct linkest_header {
+  nx_uint8_t flags;
+  nx_uint8_t seq;
+} linkest_header_t;
+
+
+// for outgoing link estimator message
+// so that we can compute bi-directional quality
+typedef nx_struct neighbor_stat_entry {
+  nx_am_addr_t ll_addr;
+  nx_uint8_t inquality;
+} neighbor_stat_entry_t;
+
+// we put the above neighbor entry in the footer
+typedef nx_struct linkest_footer {
+  neighbor_stat_entry_t neighborList[1];
+} linkest_footer_t;
+
+
+// Flags for the neighbor table entry
+enum {
+  VALID_ENTRY = 0x1, 
+  // A link becomes mature after BLQ_PKT_WINDOW
+  // packets are received and an estimate is computed
+  MATURE_ENTRY = 0x2,
+  // Flag to indicate that this link has received the
+  // first sequence number
+  INIT_ENTRY = 0x4,
+  // The upper layer has requested that this link be pinned
+  // Useful if we don't want to lose the root from the table
+  PINNED_ENTRY = 0x8
+};
+
+
+// neighbor table entry
+typedef struct neighbor_table_entry {
+  // link layer address of the neighbor
+  am_addr_t ll_addr;
+  // last beacon sequence number received from this neighbor
+  uint8_t lastseq;
+  // number of beacons received after last beacon estimator update
+  // the update happens every BLQ_PKT_WINDOW beacon packets
+  uint8_t rcvcnt;
+  // number of beacon packets missed after last beacon estimator update
+  uint8_t failcnt;
+  // flags to describe the state of this entry
+  uint8_t flags;
+  // MAXAGE-inage gives the number of update rounds we haven't been able
+  // update the inbound beacon estimator
+  uint8_t inage;
+  // inbound qualities in the range [1..255]
+  // 1 bad, 255 good
+  uint8_t inquality;
+  // EETX for the link to this neighbor. This is the quality returned to
+  // the users of the link estimator
+  uint16_t eetx;
+  // Number of data packets successfully sent (ack'd) to this neighbor
+  // since the last data estimator update round. This update happens
+  // every DLQ_PKT_WINDOW data packets
+  uint8_t data_success;
+  // The total number of data packets transmission attempt to this neighbor
+  // since the last data estimator update round.
+  uint8_t data_total;
+} neighbor_table_entry_t;
+
+
+#endif