Contact: Ljubica Blazevic
The Terminode project is concerned with wide area, wireless mobile networks, which are autonomous, self-organized, and independent of any fixed infrastructure. In a Terminode network, all networking functions are embedded in the terminals themselves, which are, indeed, called terminodes, since they act as terminals and packet forwarding network nodes at the same time. Terminodes can communicate with each other directly or via other terminodes that relay communications.
The vision of the Terminode project can be illustrated by a free, amateur, wireless network covering a wide area, which operates at unlicensed frequencies. In this scenario, terminodes are small personal devices potentially owned by everybody in the area. Thus, the size of the network can be very large; it could reach several million devices in regions of high density population. Terminode users can be humans or equipments, depending on the application. Communication among users is based on multi-hop wireless communication of voice and data.
The aim of the following doctoral school project is to verify the geodesic packet forwarding mechanism in a terminode network, as described in the technical report SSC31. Packet forwarding works as follows. As destination addresses, packets contain both the EUI and an estimate of the LDA of the destination. A terminode keeps the EUIs and LDAs of all current friends; when it receives a packet, it checks whether the destination EUI is in the list of friends, and if so, sends it to the destination (local packet forwarding). Otherwise, it looks at the destination LDA and computes an estimate of which friend is closer to the destination, from a geographical viewpoint (geodesic packet forwarding); then it sends the packet to that friend. Looping packets are discarded by the beans mechanism described below (similar to the TTL field in IP packets). Convergence of the scheme requires some properties of the distribution of friends. In the beginning, we assume to have a MAC layer, i.e. the IEEE 802.11 Mac layer, where a node broadcasts the message and the MAC layer takes care to deliver it to the wished node(s), for example by limiting the transmission coverage. The project aim is to compare (in terms of how many packets ever reach the destination; how many hops in average are needed before the packet reaches the destination; the amount of the overhead messages) the performance of several packet forwarding algorithms based on geopraphycal coordinates:
1) The packet forwarding method applied in the DREAM project (University of Texas) where the message from node A to node B is not forwarded only to A`s friend that is “closest” to B, but is forwarded to the number of friends of A. Those friends are estimated to be in the vicinity of node B.
2) the terminode proposal where the message is sent to the A`s friend estimated to be the closest to node B.
Domain:
Other; Protocol design and implementation
Student info:
Alok Agarwal