PRoPHET with LEGO Mindstorms

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PRoPHET with LEGO Mindstorms
The Goal of the Project The task in this project
is to implement the PRoPHET (Probabilistic
Routing Protocol using History of Encounters and
Transitivity) and Epidemic routing protocol for
the LEGO Mindstorms platform (RCX), and then do a
comparison between the two protocols by
evaluating the results from our test runs. The
LEGO robots will act as nodes in an
intermittently connected network.
PRoPHET PRoPHET is a routing protocol for
intermittently connected networks. In such
networks there are no guarantees that a fully
connected path between the sources and the
destinations exists at all time. To send messages
through these kind of networks, PRoPHET uses a
probability function to determine which path the
packet should choose.
Epidemic Routing Epidemic is a simple routing
protocol for intermittently connected networks.
It basically forwards all messages to all node it
meets, hence flooding the network. When the
receive buffer is full it will write over the old
messages.
Test setup The robots are kept inside areas,
where they are supposed to communicate with their
neighbours when an opportunity arise.
The tables below show the
probability from a specific node to the other
nodes calculated by PRoPHET from some of our test
runs.
About LEGO Mindstorms Lego Mindstorms are the
next generation of LEGO. Simply it is a
microcomputer where you can connect different
devices, such as motors, light sensors, triggers.
Its also capable of transmitting and receiving
IR (infra red), which is vital to this project,
since we want to send and receive data from the
different nodes in the network. The internal
memory in the Robot is 32Kb. The Robots has an
OS called BrickOS, which is an alternative
operating system for the Lego Mindstorms (RCX). 
It provides a C/C development environment for
RCX.
Results The results are derived from the data
collected through our test runs. Below are two
diagrams showing how the two protocols compare
with respect to delivery ratio and average sent
messages per node. The left diagram
clearly shows PRoPHET having a higher delivery
rate than Epidemic when buffer size is limited.
The right diagram shows that PRoPHET is also
utilizing less resources.
Node Id1 Id2 0.5743 Id3 0.1644 Id4 0.0697 Id5
0.2344 Id6 0.1178
Node Id3 Id1 0.0901 Id2 0.2999 Id4 0.3601 Id5
0.3634 Id6 0.1404
Node Id2 Id1 0.5965 Id3 0.3659 Id4 0.1679 Id5
0.5881 Id6 0.2700
Node Id4 Id1 0.0406 Id2 0.0915 Id3 0.2931 Id5
0.2057 Id6 0.0741
Node Id6 Id1 0.1422 Id2 0.2623 Id3 0.2394 Id4
0.1912 Id5 0.5763
Node Id5 Id1 0.2532 Id2 0.5144 Id3 0.5466 Id4
0.2992 Id6 0.6054
Members Patrik Vesterlund
Andreas Browall Jonas
Frisk Pontus
Johansen Supervisors Anders Lindgren
Kaustubh Phanse