Coping
with episodic connectivity in heterogeneous networks
Rao Naveed
Bin Rais (Planete, INRIA Sophia Antipolis, France)
Thierry
Turletti (Planete, INRIA Sophia Antipolis, France)
Katia
Obraczka (
We present an efficient message
delivery mechanism that enables distribution/dissemination of messages in an
internet connecting heterogeneous networks and prone to disruptions in
connectivity. We call our protocol MeDeHa (pronounced “medea”) for Message
Delivery in Heterogeneous, Disruption prone Networks. MeDeHa is complementary
to the IRTF’s Bundle Architecture: while the Bundle Architecture provides
storage above the transport layer in order to enable interoperability among
networks that support different types of transport layers, MeDeHa stores data
at the link layer addressing heterogeneity at lower layers (e.g., when
intermediate nodes do not support higher-layer protocols). MeDeHa also takes
advantage of network heterogeneity (e.g., nodes supporting more than one
network) to improve message delivery. For example, in the case of IEEE 802.11
networks, we use both infrastructure- and ad hoc modes to deliver data to
otherwise unavailable destinations. Another important feature of MeDeHa is that
there is no need to deploy special-purpose nodes such as message ferries, data
mules, or throwboxes in order to relay data to intended destinations, or to
connect to the backbone network wherever infrastructure is available. The
network is able to store data destined to temporarily unavailable nodes for
some time depending upon available storage as well as quality-of-service issues
such as delivery delay bounds imposed by the application. We evaluate MeDeHa
via simulations using indoor scenarios (e.g. convention centers, exposition
halls, museums etc.) and show significant improvement in delivery ratio in the
face of episodic connectivity. We also showcase MeDeHa’s support for different
levels of quality-of-service through traffic differentiation and message
prioritization.
Modified
Version of INET Framework (OMNET++) (click
here to download)
INET
Simulation Scripts (click here to download)