End-to-end acknowledgement of geocast in vehicular networks

Abstract

Vehicular networks suffer from fundamental reliability problems, which preclude basing safety-critical decisions on the expected outcome of communication. To enable safe, distributed decision making, reliable feedback on the success of communication is of critical importance. In this paper, we address the problem of end-to-end acknowledgement of geocast, in order to allow an application to know to which vehicles its geocast messages were successfully transmitted. Acknowledgements are gathered in a wave of fixed velocity to obtain results with a predictable delay. Acknowledgements are aggregated into larger messages and aggregators are selected using consistent hashing to increase the probability of acknowledgements from different vehicles being forwarded to the same aggregator. The source is found using a combination of a sink tree towards its original position, which is overlaid on the road network, and position updates by the source. We show that the algorithm is effective under various traffic conditions on a simulated highway.

Analysis of a receiver-based reliable broadcast approach for vehicular networks

“…This approach is based on acknowledging the received messages to assure reliable delivery by indexing the copy of the messages. In [16] an end-to-end geocast acknowledgement scheme is proposed, in which individual acknowledgements are accumulated into larger messages in an aggregator. The acknowledgement is later sent to the source using a sink tree and position update schemes in order to find the path back towards the source.…”

“…We approximate the number of time slots before sending a reply by assuming that all N − i stations that have the packet do receive the request. Recalling that all the stations missing the packet, choose the back-off counter from a geometric distribution with the same parameter r R to send a retransmission request, the number of time slots to access the channel is geometrically distributed with parameter (16) which follows from the definition of the minimum of a set of random variables and the memoryless property of a geometric distribution. Similarly, the number of time slots to access the channel for sending the data packet is geometrically distributed with parameter…”

Analysis of multi-hop broadcast in vehicular ad hoc networks: A reliability perspective

“…Simple flooding was found to outperform the other two in terms of delay and delivery ratio. In [9] an end-to-end geocast acknowledgement scheme is proposed, in which individual ACKs are accumulated into larger messages in an aggregator and further forwarded back over multiple hops to the original source. The authors based their studies on simulations and examined the approach in terms of overhead and reliability.…”

Reliable Broadcasting in Vehicular Networks

“…This approach is based on acknowledging the received messages to assure reliable delivery by indexing the copy of the messages. In [120] an end-to-end geocast acknowledgement scheme is proposed, in which individual acknowledgments are accumulated into larger messages in an aggregator. The acknowledgement is later sent to the source using a sink tree and position update schemes in order to find the path back towards the source.…”

“…Though simple flooding outperforms the other two in terms of delay and delivery ratio, none of them has a explicit error recovery implemented. In [120] an E2E geocast acknowledgement scheme is proposed, in which individual ACKs are accumulated into larger messages in an aggregator and further forwarded back over multiple hops to the original source.…”