University of Porto | Date: 2013-11-07
Method and system of key distribution by trusted nodes for a vehicular ad hoc network, the nodes of said network having at least one pair of public-private keys and the corresponding certificates, issued by a CA, said method comprising each vehicle node, on entering said network region, requesting a set of keys from an RSU node that is within range and within that region, said RSU node sending said vehicle node a set of private keys, selected from a pool of private keys, and a list with the key identifiers of the private keys shared by said vehicle node and the other vehicle nodes that have most recently contacted said RSU for a predetermined period of time; such that two nodes are able to establish a secure connection without further interaction by deriving a shared secret which is a cryptographic hash function of the keys shared by said two nodes.
University of Porto and Carnegie Mellon University | Date: 2013-09-30
A method for multi-hop forwarding of data packets in vehicular ad-hoc networks is disclosed. Each node knows both its own and the destinations geographical coordinates. The coordinates of the one-hop neighbors are obtained from periodically broadcast Cooperative-Awareness Messages (CAMs). The method comprises the following distributed coordination scheme, executed by each node upon receiving a packet: i) computing the set of candidate forwarders; ii) ranking the candidate forwarders according to an utility metric; iii) forwarding the packet after a period of time proportional to its rank if top-ranked, dropping the packet otherwise. The base utility metric used for ranking forwarders is the inverse of the distance to the destination. Moreover, an extension is disclosed where this metric is replaced by the inverse of the expected number of packet transmissions to reach the destination. The latter metric is calculated based on spatial connectivity information cooperatively collected by nodes in the network.
University of Porto and Carnegie Mellon University | Date: 2011-07-15
Systems, methods, software, and apparatuses for coordinating traffic proximate to a potential conflict zone, such as a roadway intersection, where travel conflicts, such as crossing traffic, can arise. Coordination involves forming an ad-hoc network in a region containing the conflict zone using, for example, vehicle-to-vehicle communications and developing a dynamic traffic control plan based on information about vehicles approaching the conflict zone. Instructions based on the dynamic traffic control plan are communicated to devices aboard vehicles in the ad-hoc network, which display one or more virtual traffic signals to the operators of the vehicles and/or control the vehicles in accordance with the dynamic traffic control plan.
University of Porto | Date: 2012-09-03
The present subject-matter relates to transmitting a real-time data stream, namely simultaneously to multiple receivers over unreliable networks (e.g. wireless multicast), in a timely and reliable manner, in particular to a method, apparatus and computer program product for feedback-based real-time network coding. It is disclosed a computer-implemented method for a transmitting node, a receiving node, and an intermediate node of feedback-based real-time network coding from a transmitter and to one or more receivers, in particular comprising a linear combination of packets from the transmitter; determining whether the received linear combination of packets is linearly independent of previous linear combinations of packets; determining the validity of a priority level of the packets; determining validity of the deadline of the packets; determining whether a packet is to be removed from a transmit queue, and if determined removing it. There are also disclosed said transmitting, receiving, and intermediate nodes.
University of Porto | Date: 2012-06-04
The present invention relates to a method for detecting resistant microorganisms to a therapeutic agent in a biological sample, comprising the following steps: Therefore, the present invention is useful in laboratory procedures or routines for the detection of the susceptibility of different microorganisms to a therapeutic agent, to the determination of microorganisms resistance mechanisms or even to evaluate the amount of antimicrobial drug in the biological sample.