
% $Id: discussion.tex,v 1.3 2005/04/08 21:21:45 gokhale Exp $

\subsection{Discussion}
\label{sec:discussion}

This section summarizes the EASM performance compared to other data
dissemination schemes we have studied.
\begin{enumerate}
  \item {\bf Sink movement pattern:} EASM handles localized mobility
pattern by sending the data response towards the grid center
as explained in Data Response section in the architecture.
Further, the grid center temporarily stores data response it 
received for a sink. It forwards the data when sink sends a 
query message (containing its instantaneous data) to that
grid center. Both TTDD and Index Based schemes are suitable 
only for localized mobility patterns i.e. if the sink is within
the cell from which it originated the request in the first place.
Thus in EASM, even for increased speeds the data is delivered 
successfully to the sink that requested it.


\item {\bf Energy Consumption:} For four sink-source pairs, our
results indicate 
that the energy consumption is comparable for TTDD, DD and
EASM. However, for high sink mobility patterns EASM scales
nicely as compared to TTDD. TTDD requires a new broadcast
each time a sink enters a new cell within the grid. Naturally,
since the rate of broadcast is higher for fast moving sinks
TTDD energy consumption increases more rapidly than EASM.

\item {\bf Routing Load:} Routing load is significantly lower than
both TTDD and DD. TTDD constructs and maintains one grid per 
source node for disseminating data, which are costly operations.
In EASM on the other hand, interests (requests) and responses 
are always routed toward a destination (and are not broadcast).
\end{enumerate}
