Abstract:
Advanced Metering Infrastructure (AMI) applications
for Smart Grid (SG) typically employ wireless mesh based
data collection approaches that collect smart meter data via
multi-hop routing. One of the mesh-based solutions that is viable
to use is the IEEE 802.11s wireless mesh standard. However,
when TCP is employed in this standard for periodic smart
meter data collection, the performance starts to degrade due to
classical congestion mechanism of TCP which is falsely triggered
due to the link failures. The main reason for frequent link
failures is the occurring of collisions among beacons sent by the
Peering Management Protocol (PMP) of IEEE 802.11s standard
to maintain link connectivity among the smart meters (SMs). This
in turn causes doubling of the retransmission timeout (RTO) of
TCP assuming that there is congestion and thus introduces extra
overhead and packet delay. In this paper, we propose a cross-layer
approach to inform the transport layer about the link failures
happening at the MAC layer. To this end, path error information
from the routing protocol of IEEE 802.11s is exploited. The idea
is to eliminate the unnecessary doubling of the RTO timer when
there is a link failure. We evaluated the proposed mechanism
through simulation using ns-3 simulator. The results indicate that
significant network performance improvement in terms of endto-
end delay and collection time can be achieved by employing
our approach. The simulation results also show that further
improvement in collection time can be achieved when an upper
bound limit is enforced for the RTO timer.
