The
expriment purpose was to first,
take a node-to-node baseline and second, repeate the
test conducted on July 30th, eliminating time synchronization issues to confirm
pervious results, please refer to the problem section
here
for more information.
Deployment
location
P2P Baseline:
We ran a 20 minutes
baseline to determine the packet drop rate without modems competing for channel
access. Baseline was ran at 0.15
packet/seconds where only MID2 is sending to MID1. Total of 74 packets was sent
from MID2 to MID3 in which 1 packet failed to arrive at MID1. As it was
expected, for this particular channel we have ~%99 success rate.
Back-off
Figure below compares back-off throughput to prior field experiments.
Throughput comparison between
pure Aloha with no back-off and the new back-off scheme
Table below shows
packet loss rate which is comparable to the July 30th experiment.
Packet Loss Rate Percentage
TX_Rate |
Back-off July 30th (%) |
Back-off Sept. 21st (%) |
0.05 |
31 |
31 |
0.08 |
44 |
39 |
0.10 |
39 |
39 |
0.15 |
44 |
41 |