Network-layer geocast: geographic addressing and routing for fixed networks

There is an increasing number of always connected devices in the world, of which many are mobile. Many of these devices can benefit from location-dependent data. In the case of connected vehicles, examples could be local traffic information, accident notifications and weather information. This information could be meant for a single intersection, an entire road or even a city. Sources of this type of information could be local, but many would likely be located further in the network, or in a different network altogether.

In today's Internet, location-dependent data is either sent to a host by having the host actively request it, or by some sort of central authority (for a specific application) keeping track of the host's location and sending it the relevant data. All of this is achieved by using unicast communication. The result is that hosts close to each other will likely receive identical data, which is transmitted multiple times over the network. If data could be sent to a specific area instead of only to host-specific network addresses, we could reduce the load on the network for this type of communication. Sending data to a location is generally referred to as geocast.

In this thesis we research, design and evaluate a system which could enable geocast both within and between networks. We design a addressing system that can address areas anywhere on the planet. We evaluate different forwarding trees for their link usage and fairness when applied to geographically scoped destinations. We design, implement a prototype and evaluate both a path-based and distance-vector-based geographic forwarding algorithm. We design and evaluate a system that can help vehicles forward messages between themselves by using geocast-enabled infrastructure when available.

All of these proposals combined allow a packet to be routed from a source to all devices in a geographic area. This source can also be located in a different network, as our path-based routing proposal can potentially enable inter-network routing. The message could even traverse multiple networks before the networks that actually cover the destination are reached. We hope that all these proposals combined provide the building blocks that will eventually lead to Internet-wide geocast support.