Add tinyos.sh, a utility for changing the active tree (TOSROOT).

[tinyos-2.x.git] / doc / txt / tep124.txt

diff --git a/doc/txt/tep124.txt b/doc/txt/tep124.txt
index ab5c8c595370548d1b357248212ac56717ee54d3..3a16cfe9128ce91d86f7327015a9af3ee91ba97e 100644 (file)
--- a/doc/txt/tep124.txt
+++ b/doc/txt/tep124.txt
@@ -34,10 +34,10 @@ links to the neighbors.
 Routing protocols often require bi-directional link qualities to
 compute the routes. Nodes can estimate the quality of the in-bound
 link from a neighbor by estimating the ratio of successfully received
-messages and the total transmitted messages. These in-bound link
-qualities are exchanged among the neighbors using LEEP to determine
-the out-bound link qualities. Bi-directional link quality is computed
-using thus learned in-bound and out-bound link qualities.
+messages and the total transmitted messages. LEEP appends in-bound
+packet reception rate (PRR) estimates to packets. Other nodes hearing 
+these packets can combine the in-bound PRR values with their own
+in-bound values to compute bi-directional link quality.
 
 2. Definitions
 ============================================================================
@@ -45,11 +45,13 @@ using thus learned in-bound and out-bound link qualities.
 2.1 Link Quality
 --------------------------------------------------------------------
 
-Quality of the link between any two nodes describes the probability
-with which data link layer packets can be received without any
-error. This definition assumes uncorrelated link losses. The link
-between the nodes A and B may have different quality in A to B and B
-to A directions.
+The link quality between a directed node pair (A,B) is the probability
+that a packet transmitted by A will be successfully received by B. The
+bidirectional link quality of an undirected node pair (A,B) is the 
+product of the link quality of (A,B) and (B,A). This definition
+assumes independent link losses. It also includes the case when
+the link quality of (A,B) and (B,A) are different; this can occur
+due to local interference or noise.
 
 2.2 In-bound Link Quality
 --------------------------------------------------------------------
@@ -126,10 +128,10 @@ Information entry.
 The following diagram shows the LEEP header format::
 
                            1
-       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6
-      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-      |nentry | rsrvd |      seqno      |
-      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      |nentry | rsrvd |     seqno     |
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 
 
 Field definitions:
@@ -145,10 +147,10 @@ Field definitions:
 The following diagram shows the Link Information Entry format::
 
                            1
-       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6
-      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-      |             node id             |
-      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      |            node id            |
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       | link quality  |
       +-+-+-+-+-+-+-+-+