Sensor network clustering and data aggregation (iHEED)
------------------------------------------------------

Author: Ossama M. Younis (oyounis@cs.purdue.edu).
Affiliation: Purdue University, Department of Computer Science.
First release: January 10, 2005.

---------------------------------------------------------------------------

The provided code extends TinyOS v.1.1 (http://www.tinyos.net). Below is a 
description of the modified files and a description of the modifications.

1) tos/interfaces/RouteControl.nc: defines new functions for declaring if
the node is a cluster head or is currently in a clustering process.

2) tos/interfaces/EnergyControl.nc: defines functions for for tracking
energy consumption of the mote.

3) tos/lib/Route/MultiHop.h: defines CLUSTERING_ON to enable node clustering

4) tos/lib/Route/MultiHopRouter.nc: binds the energy controller and clustering
timers to their corresponding components.

5) tos/lib/Route/MultiHopEngineM.nc: energy control and packet capture if 
the node is a cluster head

6) tos/lib/Route/MultiHopLEPSM.nc: link estimation and parent selection for
tree routing. Implements the main clustering process of the HEED algorithm.

7) apps/surge.h: extends the SurgeMsg fields to include the node remaining 
power, overhead, and the neighboring nodes that are still alive

8) apps/Surge.nc: for energy control and packet interception

9) apps/SurgeM.nc: the main application that uses multi-hop routing and data
aggregation. A cluster head aggregates the data it receives before forwarding
it on the routing tree. The routing tree is constructed only on the cluster
head overlay