Supporting Beacon and Event-Driven Messages in Vehicular Platoons through Token-Based Strategies

[EN] Timely and reliable inter-vehicle communications is a critical requirement to support traffic safety applications, such as vehicle platooning. Furthermore, low-delay communications allow the platoon to react quickly to unexpected events. In this scope, having a predictable and highly effective medium access control (MAC) method is of utmost importance. However, the currently available IEEE 802.11p technology is unable to adequately address these challenges. In this paper, we propose a MAC method especially adapted to platoons, able to transmit beacons within the required time constraints, but with a higher reliability level than IEEE 802.11p, while concurrently enabling efficient dissemination of event-driven messages. The protocol circulates the token within the platoon not in a round-robin fashion, but based on beacon data age, i.e., the time that has passed since the previous collection of status information, thereby automatically offering repeated beacon transmission opportunities for increased reliability. In addition, we propose three different methods for supporting event-driven messages co-existing with beacons. Analysis and simulation results in single and multi-hop scenarios showed that, by providing non-competitive channel access and frequent retransmission opportunities, our protocol can offer beacon delivery within one beacon generation interval while fulfilling the requirements on low-delay dissemination of event-driven messages for traffic safety applications.This work was partially supported by the Knowledge Foundation (KKS) via the ELECTRA project, the SafeCOP project, which is funded from the ECSEL Joint Undertaking under grant agreement n0 692529, and from national funding.Balador, A.; Uhlemann, E.; Tavares De Araujo Cesariny Calafate, CM.; Cano, J. (2018). Supporting Beacon and Event-Driven Messages in Vehicular Platoons through Token-Based Strategies. Sensors. 18(4):1-17. https://doi.org/10.3390/s18040955S117184Omar, H. A., Zhuang, W., & Li, L. (2013). VeMAC: A TDMA-Based MAC Protocol for Reliable Broadcast in VANETs. IEEE Transactions on Mobile Computing, 12(9), 1724-1736. doi:10.1109/tmc.2012.142Bergenhem, C., Hedin, E., & Skarin, D. (2012). Vehicle-to-Vehicle Communication for a Platooning System. Procedia - Social and Behavioral Sciences, 48, 1222-1233. doi:10.1016/j.sbspro.2012.06.1098Hadded, M., Muhlethaler, P., Laouiti, A., Zagrouba, R., & Saidane, L. A. (2015). TDMA-Based MAC Protocols for Vehicular Ad Hoc Networks: A Survey, Qualitative Analysis, and Open Research Issues. IEEE Communications Surveys & Tutorials, 17(4), 2461-2492. doi:10.1109/comst.2015.2440374Fernandes, P., & Nunes, U. (2012). Platooning With IVC-Enabled Autonomous Vehicles: Strategies to Mitigate Communication Delays, Improve Safety and Traffic Flow. IEEE Transactions on Intelligent Transportation Systems, 13(1), 91-106. doi:10.1109/tits.2011.2179936Hassanabadi, B., & Valaee, S. (2014). Reliable Periodic Safety Message Broadcasting in VANETs Using Network Coding. IEEE Transactions on Wireless Communications, 13(3), 1284-1297. doi:10.1109/twc.2014.010214.122008OMNeT++http://www.omnetpp.orgSommer, C., German, R., & Dressler, F. (2011). Bidirectionally Coupled Network and Road Traffic Simulation for Improved IVC Analysis. IEEE Transactions on Mobile Computing, 10(1), 3-15. doi:10.1109/tmc.2010.133Akhtar, N., Ergen, S. C., & Ozkasap, O. (2015). Vehicle Mobility and Communication Channel Models for Realistic and Efficient Highway VANET Simulation. IEEE Transactions on Vehicular Technology, 64(1), 248-262. doi:10.1109/tvt.2014.231910

A reliable token-based MAC protocol for delay sensitive platooning applications

© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Platooning is both a challenging and rewarding application. Challenging since strict timing and reliability requirements are imposed by the distributed control system required to operate the platoon. Rewarding since considerable fuel reductions are possible. As platooning takes place in a vehicular ad hoc network, the use of IEEE 802.11p is close to mandatory. However, the 802.11p medium access method suffers from packet collisions and random delays. Most ongoing research suggests using TDMA on top of 802.11p as a potential remedy. However, TDMA requires synchronization and is not very flexible if the beacon frequency needs to be updated, the number of platoon member changes or if retransmissions for increased reliability are required. We therefore suggest a token-passing medium access method where the next token holder is selected based on beacon data age. This has the advantage of allowing beacons to be re-broadcasted in each beacon interval whenever time and bandwidth is available. We show that our token-based method is able to reduce the data age and increase reliability considerably compared to pure 802.11p.This work was partially supported by the Ministerio de Ciencia e Innovación, Spain, under Grant TIN2011-27543- C03-01. Balador is funded by ERASMUS+ programme, and Böhm and Uhlemann are also funded by the Knowledge Foundation through the ACDC projectBalador, A.; Böhm, A.; Uhlemann, E.; Tavares De Araujo Cesariny Calafate, CM.; Cano Escribá, JC. (2015). A reliable token-based MAC protocol for delay sensitive platooning applications. IEEE. https://doi.org/10.1109/VTCFall.2015.7390813

Communication requirements of emerging cooperative driving systems

Traffic safety applications relying on cooperative systems are currently being considered by several research projects worldwide. An important question is if existing wireless technologies can meet the communication requirements from this emerging field of applications? Part of the answer to this question is that the communication requirements depend on what is actually communicated and how this information is used by and presented to the driver. The data traffic from realizations based on "cooperative awareness" or on "hazard warnings" are very different. This article discusses the communication requirements of some typical traffic safety applications and how these requirements are affected by different realizations.©2011 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.R2D

Hybrid ARQ Using Serially Concatenated Block Codes for Real-Time Communication - An Iterative Decoding Approach

The ongoing wireless communication evolution offers improvements for industrial applications where traditional wireline solutions causes prohibitive problems in terms of cost and feasibility. Many of these new wireless applications are packet oriented and timecritical. The deadline dependent coding (DDC) communication protocol presented here is explicitly intended for wireless real-time applications. The objective of the work described in this thesis is therefore to develop the foundation for an efficient and reliable real-time communication protocol for critical deadline dependent communication over unreliable wireless channels

Adaptive Concatenated Coding for Wireless Real-Time Communications

The objective of this thesis is to improve the performance of real-time communication overa wireless channel, by means of specifically tailored channel coding. The deadlinedependent coding (DDC) communication protocol presented here lets the timeliness and thereliability of the delivered information constitute quality of service (QoS) parametersrequested by the application. The values of these QoS parameters are transformed intoactions taken by the link layer protocol in terms of adaptive coding strategies.Incremental redundancy hybrid automatic repeat request (IR-HARQ) schemes usingrate compatible punctured codes are appealing since no repetition of previously transmittedbits is made. Typically, IR-HARQ schemes treat the packet lengths as fixed and maximizethe throughput by optimizing the puncturing pattern, i.e. the order in which the coded bitsare transmitted. In contrast, we define an IR strategy as the maximum number of allowedtransmissions and the number of code bits to include in each transmission. An approach isthen suggested to find the optimal IR strategy that maximizes the average code rate, i.e., theoptimal partitioning of n-kparity bits over at most M transmissions, assuming a givenpuncturing pattern. Concatenated coding used in IR-HARQ schemes provides a new arrayof possibilities for adaptability in terms of decoding complexity and communication timeversus reliability. Hence, critical reliability and timing constraints can be readily evaluatedas a function of available system resources. This in turn enables quantifiable QoS and thusnegotiable QoS. Multiple concatenated single parity check codes are chosen as examplecodes due to their very low decoding complexity. Specific puncturing patterns for thesecomponent codes are obtained using union bounds based on uniform interleavers. Thepuncturing pattern that has the best performance in terms of frame error rate (FER) at a lowsignal-to-noise ratio (SNR) is chosen. Further, using extrinsic information transfer (EXIT)analysis, rate compatible puncturing ratios for the constituent component code are found.The puncturing ratios are chosen to minimize the SNR required for convergence.The applications targeted in this thesis are not necessarily replacement of cables inexisting wired systems. Instead the motivation lies in the new services that wireless real-time communication enables. Hence, communication within and between cooperatingembedded systems is typically the focus. The resulting IR-HARQ-DDC protocol presentedhere is an efficient and fault tolerant link layer protocol foundation using adaptiveconcatenated coding intended specifically for wireless real-time communications.Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie, 2198, Technical report. D, 29,</p

Cooperative systems for traffic safety : Will existing wireless access technologies meet the communications requirements?

Traffic safety applications relying on cooperative systems are currently being considered by several research projects worldwide. An important question is if existing wireless technologies can meet the communication requirements from this emerging field ofvapplications? Part of the answer to the question is that the communication requirements depend on implementation. The data traffic from realizations based on “cooperative awareness” or on “hazard warnings” are very different. This article discusses the communication requirements of some typical traffic safety applications, how these requirements are affected by different realizations and finally what is required from a wireless access technology to support these applications

Joint design of relay and packet combining schemes for wireless industrial networks

Wireless industrial networks differ in many respects from other types of wireless networks. In particular, since many applications impose tight real-time and reliability requirements at the same time, and packet sizes tend to be small. In this paper we design a simple and practically implementable protocol in which relaying and packet combining work together to improve the probability that packets are delivered within a prescribed deadline over fading channels. The results indicate that such a combination can be fruitfully employed in wireless industrial networks.©2008 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.</p

PRIOREL-COMB : A protocol framework supporting relaying and packet combining forwireless industrial networking

The PRIOREL-COMB framework presented here integrates support for relaying and packet combining into wireless industrial networks. The selection of suitable relay nodes is made using distributed algorithms which includes different eligibility tests as well as different priority assignments. The framework improves performance in terms of probability to successfully deliver packets before their deadline and it can be implemented on top of commercial transceivers without modification of the physical layer. This class of protocols will therefore be a valuable addition to future wireless industrial communication systems.©2008 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.</p