fix the description of the implementation

diff --git a/doc/txt/tep119.txt b/doc/txt/tep119.txt
index ee203b4c3bbb4a8677ad15e846acdb2fdbd0a71a..8291dd3464e341957e76c00b4f705f83f78110fe 100644 (file)
--- a/doc/txt/tep119.txt
+++ b/doc/txt/tep119.txt
@@ -251,28 +251,29 @@ forwarding policies, such as queueing and timing.
 LinkEstimatorP estimates the quality of link to or from each
 neighbor. In this TEP, we briefly describe the reference
 implementation in ''tinyos-2.x/tos/lib/4bitle'' and refer the readers
 LinkEstimatorP estimates the quality of link to or from each
 neighbor. In this TEP, we briefly describe the reference
 implementation in ''tinyos-2.x/tos/lib/4bitle'' and refer the readers

-to [3]_ for detailed description of the estimator.
+to [3]_ for a detailed description of the estimator.

 
 Link estimation is decoupled from the establishment of routes. There
 is a narrow interface -- LinkEstimator and CompareBit -- between the
 
 Link estimation is decoupled from the establishment of routes. There
 is a narrow interface -- LinkEstimator and CompareBit -- between the

-link estimator and the routing engine. The one requirement is that the
-quality returned is standardized. A smaller return value from
-LinkEstimator.getLinkQuality() MUST imply that the link to the
-neighbor is estimated to be of a higher quality than the one that
-results in a larger return value. The range of value SHOULD be
-[0,65535] and the variation in link quality in that range SHOULD be
-linear. Radio provided values such as LQI or RSI, beacon based link
-estimation to compute ETX, or their combination are some possible
-approaches to estimating link qualities. The routing engine instructs
+link estimator and the routing engine. A smaller return value from
+LinkEstimator.getLinkQuality() implies that the link to the neighbor
+is estimated to be of a higher quality than the one that results in a
+larger return value. Radio provided values such as LQI or RSI, beacon
+based link estimation to compute ETX, or their combination are some
+possible approaches to estimating link qualities. LinkEstimatorP
+returns (ETX-1)*10 as the link quality. The routing engine instructs

 LinkEstimatorP to insert the neighbor, through which a high quality
 path to the root can be constructed, into the neighbor table by
 returning TRUE when LinkEstimatorP signals Comparebit.shouldInsert()
 for the newly discovered neighbor.
 
 LinkEstimatorP to insert the neighbor, through which a high quality
 path to the root can be constructed, into the neighbor table by
 returning TRUE when LinkEstimatorP signals Comparebit.shouldInsert()
 for the newly discovered neighbor.
 

-LinkEstimatorP MAY have its own control messages to compute
-bi-directional link qualities. LinkEstimatorP provides calls (txAck(),
-txNoAck(), and clearDLQ()) to update the link estimates based on
-successful or unsuccessful data transmission to the
+LinkEstimatorP does not generate its own control messages to compute
+link qualities. When a user of LinkEstimatorP (CtpRoutingEngineP, for
+example) sends a packet using the Send interface provided by
+LinkEstimatorP, link estimation information is also sent with the
+packet as described in an upcoming TEP [4_]. LinkEstimatorP provides
+calls (txAck(), txNoAck(), and clearDLQ()) to update the link
+estimates based on successful or unsuccessful data transmission to the

 neighbors. LinkEstimatorP uses the LinkPacketMetadata interface to
 determine if the channel was of high quality when a packet is received
 from a neighbor to consider the link to that neighbor for insertion
 neighbors. LinkEstimatorP uses the LinkPacketMetadata interface to
 determine if the channel was of high quality when a packet is received
 from a neighbor to consider the link to that neighbor for insertion


@@ -328,16 +329,16 @@ policy::
 CtpRoutingEngineP is responsible for computing routes to the roots of a
 tree. In traditional networking terminology, this is part of the
 control plane of the network, and is does not directly forward any
 CtpRoutingEngineP is responsible for computing routes to the roots of a
 tree. In traditional networking terminology, this is part of the
 control plane of the network, and is does not directly forward any

-data packets, which is the responsibility of CtpForwardingEngine. 
+data packets, which is the responsibility of CtpForwardingEngineP. 

 The main interface between the two is UnicastNameFreeRouting.
 
 The main interface between the two is UnicastNameFreeRouting.
 

-CtpRoutingEngineP uses the LinkEstimator interface to learn
-about the nodes in the neighbor table maintained by LinkEstimatorP and
-the quality of links to and from the neighbors. The routing protocol
-on which collection is implemented MUST be a tree-based routing
-protocol with a single or multiple roots. CtpRoutingEngineP 
-allows a node to be configured as a root or a non-root node
-dynamically. CtpRoutingEngineP maintains multiple candidate next hops::
+CtpRoutingEngineP uses the LinkEstimator interface to learn about the
+nodes in the neighbor table maintained by LinkEstimatorP and the
+quality of links to and from the neighbors. The routing protocol on
+which collection is implemented computes a routing tree with a single
+or multiple roots. CtpRoutingEngineP allows a node to be configured as
+a root or a non-root node dynamically. CtpRoutingEngineP maintains
+multiple candidate next hops::

 
   generic module CtpRoutingEngineP(uint8_t routingTableSize, 
                                    uint16_t minInterval, 
 
   generic module CtpRoutingEngineP(uint8_t routingTableSize, 
                                    uint16_t minInterval, 


@@ -495,3 +496,5 @@ well as the configuration MultihopLqiP.
 .. [2] TEP 123: The Collection Tree Protocol (CTP) 
 
 .. [3] Rodrigo Fonseca, Omprakash Gnawali, Kyle Jamieson, and Philip Levis. "Four Bit Wireless Link Estimation." In Proceedings of the Sixth Workshop on Hot Topics in Networks (HotNets VI), November 2007
 .. [2] TEP 123: The Collection Tree Protocol (CTP) 
 
 .. [3] Rodrigo Fonseca, Omprakash Gnawali, Kyle Jamieson, and Philip Levis. "Four Bit Wireless Link Estimation." In Proceedings of the Sixth Workshop on Hot Topics in Networks (HotNets VI), November 2007

+
+.. [4] TEP 124: The Link Estimation Exchange Protocol (LEEP)