Time Barrier-Based Emergency Message Dissemination in Vehicular Ad-hoc Networks

Abstract

With the advancement in technology and inception of smart vehicles and smart cities, every vehicle can communicate with the other vehicles either directly or through ad-hoc networks. Therefore, such platforms can be utilized to disseminate time-critical information. However, in an ad-hoc situation, information coverage can be restricted in situations, where no relay vehicle is available. Moreover, the critical information must be delivered within a specific period of time; therefore, timely message dissemination is extremely important. The existing data dissemination techniques in VANETs generate a large number of messages through techniques such as broadcast or partial broadcast. Thus, the techniques based on broadcast schemes can cause congestion as all the recipients re-broadcast the message and vehicles receive multiple copies of same messages. Further, re-broadcast can degrade the coverage delivery ratio due to channel congestion. Moreover, the traditional cluster-based approach cannot work efficiently. As clustering schemes add additional delays due to communication with cluster head only. In this paper, we propose a data dissemination technique using a time barrier mechanism to reduce the overhead of messages that can clutter the network. The proposed solution is based on the concept of a super-node to timely disseminate the messages. Moreover, to avoid unnecessary broadcast which can also cause the broadcast storm problem, the time barrier technique is adapted to handle this problem. Thus, only the farthest vehicle rebroadcasts the message which can cover more distance. Therefore, the message can reach the farthest node in less time and thus, improves the coverage and reduces the delay. The proposed scheme is compared with traditional probabilistic approaches. The evaluation section shows the reduction in message overhead, transmission delay, improved coverage, and packet delivery ratio. INDEX TERMS VANET, emergency messages, data dissemination, 802.11p WAVE, probabilistic clustering, time barrier.

Blockchain for Vehicular Internet of Things: Recent Advances and Open Issues

“…Since it is difficult, if not impossible, to conduct efficient retransmissions of broadcast frames at the MAC layer, the reliability of broadcast communications becomes more difficult to achieve as compared to unicast communications [ 36 , 37 , 38 ]. The broadcast protocols should take into account both reliability and efficiency since inefficient broadcasting can cause the broadcast storm problem [ 39 , 40 ].…”

RBO-EM: Reduced Broadcast Overhead Scheme for Emergency Message Dissemination in VANETs

“…In [27], the authors propose a clustering scheme based on the time barrier technique, known as Time Barrier-Based Emergency Message Dissemination in Vehicular Adhoc Network (TBEM), to minimize unnecessary message dissemination. In their work, if an incident is observed, the farthest vehicle is used as a relay to cover more distance.…”

“…The vehicles deliver data to their cluster head for further dissemination within a cluster and, to maximize the coverage area and reduce end-to-end delay, the farthest vehicle based on Estimated Link Stability (L S T ) can be used to rebroadcast the message. Compared to the existing schemes, i.e., conventional flooding [16], TBEM [27] and DV-CAST [28], our contributions are summarized as follows.…”

“…Benkerdagh et al [26] High High End-to-end delay increases due to the post-event detection clustering process. TBEM [27] High Medium High number of retransmissions cause congestion and lower PDR. MCA-V2I [25] High High Clustering is based on BFS, which is time-consuming and, therefore, not suitable for large-scale networks.…”

“…The proposed RBO-EM scheme is compared and analyzed against conventional flooding [16] and two eminent schemes, namely, TBEM [27] and DV-CAST [28]. Performance is analyzed based on the following metrics.…”