Collection

@@ -307,6 +306,7 @@ ul.auto-toc {

Note

This memo documents a part of TinyOS for the TinyOS Community, and @@ -314,25 +314,25 @@ requests discussion and suggestions for improvements. Distribution of this memo is unlimited. This memo is in full compliance with TEP 1.

Abstract

The memo documents the interfaces, components, and semantics used by collection protocol in TinyOS 2.x. Collection provides a best-effort, multihop delivery of packets to the root of a tree.

1. Introduction

Collecting data at a base station is a common requirement of sensor network applications. The general approach used is to build one or more collection trees, each of which is rooted at a base -station. When a node has data which needs to be collected, it +station. When a node has data which needs to be collected, it sends the data up the tree, and it forwards collection data that other nodes send to it. Sometimes, depending on the form of data collection, systems need to be able to inspect packets as they go by, either to gather statistics, compute aggregates, or suppress redundant transmissions.

When a network has multiple base stations that act as root nodes, -rather than one tree, it has a forest of trees. By picking a +rather than one tree, it has a forest of trees. By picking a parent node, a collection protocol implicitly joins one of these trees. Collection provides a best-effort, multihop delivery of packets to one of a network's tree roots: @@ -347,8 +347,8 @@ family:

Loop detection, detecting when a node selects one of its descendants as a new parent.
Duplicate suppression, detecting and dealing with when lost -acknowledgments are causing packets to replicate in the +
Duplicate suppression, detecting and dealing with when lost +acknowledgments are causing packets to replicate in the network, wasting bandwidth.
Link estimation, evaluating the link quality to single-hop neighbors.

The rest of this document describes a set of components and interfaces for a collection service outlined above.

2. Collection interfaces

A node can perform four different roles in collection: producer, consumer, snooper, and in-network processor. Depending on their role, the nodes use different interfaces to interact with the collection @@ -396,8 +396,8 @@ interface RootControl { }

3 Collection Services

A collection service MUST provide one component, TreeCollectionC, which has the following signature:

@@ -462,30 +462,18 @@ command provides a measure of the quality of a node's route to the
 base station. This routing metric MUST be monotonically increasing
 across hops. In a collection tree, if node A is the parent of node B,
 then node B's metric value MUST be greater than node A's.
-
-3.1 CollectionSenderC
+
+3.1 CollectionSenderC
 Collection has a virtualized sending abstraction, the generic
 component CollectionSenderC:
-
-System Message: WARNING/2 (txt/tep119.txt, line 198)
-Literal block expected; none found.
-
-generic configuration CollectionSenderC(collection_id_t collectid) {
-
-provides {
-interface Send;
-interface Packet;
-
-
-System Message: WARNING/2 (txt/tep119.txt, line 202)
-Definition list ends without a blank line; unexpected unindent.
-}
-
-
-
-System Message: WARNING/2 (txt/tep119.txt, line 203)
-Definition list ends without a blank line; unexpected unindent.
-}
++generic configuration CollectionSenderC(collection_id_t collectid) {
+  provides {
+    interface Send;
+    interface Packet;
+  }
+}
+
 This abstraction follows a similar virtualization approach to
 AMSenderC [1], except that it is parameterized by a collection_id_t
 rather than an am_id_t. As with am_id_t, every collection_id_t SHOULD
@@ -493,8 +481,8 @@ have a single packet format, so that receivers can parse a packet
 based on its collection ID and contents.
 
 
-
-4 Implementation
+
+4 Implementation
 An implementation of this TEP can be found in
 tinyos-2.x/tos/lib/net/collection. The implementation consists of
 three major components, which are wired together to form a
@@ -504,52 +492,70 @@ of use through modularization. Neighbor management and link estimation
 are are decoupled from the routing protocol. Furthermore, the routing
 protocol and route selection are decoupled from the forwarding policies,
 such as queueing and timing.
-
-4.1 LinkEstimatorP
+
+4.1 LinkEstimatorP
 LinkEstimatorP estimates the quality of link to or from each
 neighbor. Link estimation can be done in a variety of ways, and we do
 not impose one here. It is decoupled from the establishment of
-routes. There is a narrow interface (LinkEstimator) between the link
-estimator and the routing engine. The one requirement is that the
-quality returned is standardized. A larger return value from
-LinkEstimator.getQuality(), LinkEstimator.getforwardQuality(),
-LinkEstimator.getreserveQuality() MUST imply that the link to the
-neighbor is estimated to be of a higher quality than the one that
-results in a smaller return value. The range of value SHOULD be
-[0,255] 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. LinkEstimatorP MAY have its
-own control messages to compute bi-directional link qualities:
+routes. There is a narrow interface (LinkEstimator and
+NeighborTableEviction) between the link estimator and the routing
+engine. The one requirement is that the quality returned is
+standardized. A smaller return value from LinkEstimator.getQuality(),
+LinkEstimator.getforwardQuality(), LinkEstimator.getreserveQuality()
+MUST imply that the link to the neighbor is estimated to be of a
+higher quality than the one that results in a smaller return
+value. The range of value SHOULD be [0,255] 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. 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 neighbors. The
+user of LinkEstimatorP can call insertNeighbor() to manually insert a
+node in the neighbor table, pinNeighbor() to prevent a neighbor from
+being evicted, and unpinNeighbor() to restore eviction policy:
 -typedef uint16_t neighbor_t
+typedef uint16_t neighbor_table_entry_t
 
 LinkEstimatorP {
   provides {
+    interface StdControl;
+    interface AMSend as Send;
+    interface Receive;
     interface LinkEstimator;
-    interface NeighborTable;
+    interface Init;
+    interface Packet;
+    interface LinkSrcPacket;
   }
 }
 
 interface LinkEstimator {
-  command uint8_t getLinkQuality(neighbot_t neighbor);
-  command uint8_t getReverseQuality(neighbot_t neighbor);
-  command uint8_t getForwardQuality(neighbot_t neighbor);
+  command uint8_t getLinkQuality(uint16_t neighbor);
+  command uint8_t getReverseQuality(uint16_t neighbor);
+  command uint8_t getForwardQuality(uint16_t neighbor);
+  command error_t insertNeighbor(am_addr_t neighbor);
+  command error_t pinNeighbor(am_addr_t neighbor);
+  command error_t unpinNeighbor(am_addr_t neighbor);
+  command error_t txAck(am_addr_t neighbor);
+  command error_t txNoAck(am_addr_t neighbor);
+  command error_t clearDLQ(am_addr_t neighbor);
+  event void evicted(am_addr_t neighbor);
 }
 
-interface NeighborTable {
-  event void evicted(neighbot_t neighbor)
+interface NeighborTableEviction {
+  event void evicted(uint16_t neighbor)
 }
 
 
-
-4.2 TreeRoutingEngineP
+
+4.2 TreeRoutingEngineP
 TreeRoutingEngineP is responsible for computing routes to the roots of a
 tree. It uses NeighborTable and LinkEstimator interfaces 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. TreeRoutingEngineP
+protocol with a single or multiple roots. TreeRoutingEngineP 
 allows a node to be configured as a root or a non-root node
 dynamically. TreeRoutingEngineP maintains multiple candidate next hops:
 @@ -560,7 +566,7 @@ generic module TreeRoutingEngineP(uint8_t routingTableSize) {
       interface TreeRoutingInspect;
       interface StdControl;
       interface Init;
-  }
+  } 
   uses {
       interface AMSend as BeaconSend;
       interface Receive as BeaconReceive;
@@ -575,10 +581,10 @@ generic module TreeRoutingEngineP(uint8_t routingTableSize) {
 }
 
 
-
-4.3 ForwardingEngineP
+
+4.3 ForwardingEngineP
 The ForwardingEngineP component provides all the top level interfaces
-(except RootControl) which TreeCollectionC provides and an application
+(except RootControl) which TreeCollectionC provides and an application 
 uses:
  generic module ForwardingEngineP() {
@@ -620,7 +626,7 @@ broken up into a few groups of functionality:
 
 Single hop communication: SubSend, SubReceive, SubSnoop,
 SubPacket, PacketAcknowledgments, AMPacket
-Routing: UnicastNameFreeRouting, TreeRoutingInspect,
+
Routing: UnicastNameFreeRouting, TreeRoutingInspect, 
 RootControl, CollectionId, SentCache
 Queue and buffer management: SendQueue, MessagePool,
 QEntryPool
@@ -629,10 +635,10 @@ QEntryPool
 
 
 
-
-5. Author's Address
+
+5. Author's Address
 
-Rodrigo Fonseca
+Rodrigo Fonseca 
 473 Soda Hall
 Berkeley, CA 94720-1776
 

@@ -641,9 +647,9 @@ QEntryPool
 

 

 Omprakash Gnawali
-Ronald Tutor Hall (RTH) 418
+Ronald Tutor Hall (RTH) 418 
 3710 S. McClintock Avenue
-Los Angeles, CA 90089
+Los Angeles, CA 90089 
 

 phone - +1 213 821-5627
 email - gnawali@usc.edu
@@ -652,7 +658,7 @@ QEntryPool
 Kyle Jamieson
 The Stata Center
 32 Vassar St.
-Cambridge, MA 02139
+Cambridge, MA 02139 
 

 email - jamieson@csail.mit.edu
 

@@ -667,8 +673,8 @@ QEntryPool
 email - pal@cs.stanford.edu
 
 
-
-6. Citations
+
+6. Citations