2017-ENST-0021 EDITE - ED 130 Doctorat ParisTech T H È S E pour obtenir le grade de docteur délivré par TELECOM ParisTech Spécialité « Électronique et Communications » présentée et soutenue publiquement par Laurent GALLO le 5 mai 2017 Contrôle d’accès pour Réseaux Véhiculaires Cellulaires Ad-Hoc Directeur de thèse : Prof. Jérôme HÄRRI Jury M. Christian BONNET , Professeur, EURECOM Président Mme. Carla Fabiana CHIASSERINI , Professeur, Politecnico di Torino Rapporteur M. Xavier LAGRANGE , Professeur, IMT Atlantique Rapporteur M. Erik STRÖM , Professeur, Chalmers University of Technology Examinateur M. Ozan TONGUZ , Professeur, Carnegie Mellon University Examinateur Thèse effectuée à EURECOM École de l’Institut Mines-Télécom (IMT) 2017-ENST-0021 EDITE - ED 130 T H E S I S in partial fulfillment of the requirements for the degree of Doctor of Philosophy TELECOM ParisTech Specialty « Electronics and Communications » publicly defended by Laurent GALLO on May 5, 2017 Medium Access Control for Cellular-based Vehicular Ad-Hoc Networks Advisor : Prof. Jérôme HÄRRI Jury members Mr. Christian BONNET , Professor, EURECOM President Ms. Carla Fabiana CHIASSERINI , Professor, Politecnico di Torino Reviewer Mr. Xavier LAGRANGE , Professor, IMT Atlantique Reviewer Mr. Erik STRÖM , Professor, Chalmers University of Technology Examiner Mr. Ozan TONGUZ , Professor, Carnegie Mellon University Examiner Thesis conducted at EURECOM A School of Institut Mines-Télécom (IMT) ABSTRACT Vehicle to Vehicle (V 2V) communications represent a critical enabler for safety of life applications such as Highly Autonomous Driving (HAD) , which are subject to stringent reliability constraints. 802.11 p is the current de-facto standard for V2V, formalized by European Telecommunications Standard In- stitute (ETSI) in the EU and the Federal Communication Commission (FCC) in the USA. Fast evolving cellular technologies such as 3rd Generation Part- nership Project ( 3GPP) Long Term Evolution (LTE) are also working towards V2V support. Differently from 802.11 p, however, LTE has a strict centralized communication scheduling, which is a limiting factor for the specific traffic patterns, network topology, and safety criticality requirements of V2V. Very recent evolutions of the LTE standard, enabling direct Device-to-Device (D 2D) operations, open the path towards making it a viable candidate to coexist with 802.11 p, thus providing a technological redundancy desirable for safety-of-life systems. D2D LTE , currently referred to as the Proximity Services (ProSe) , retains nonetheless a strong centralized structure, with unsupervised opera- tions being enabled only for Public Safety UEs. As a matter of fact, none of the currently available technologies has been specifically designed for the traf- fic patterns and requirements of V2V communications. V2V over LTE D2D, specifically, requires careful analysis, as many questions need to be answered: how can the control of the transmissions shift from a central entity (basesta- tion) to many, distributed, actors? How it is possible to exploit LTE ’s channel structure to enable broadcast, cross-cell, pan-operator communications? This thesis shows that unsupervised operations, currently loosely specified in ProSe , are essential for V2V. A proposition is made to address V2V needs, by splitting Medium Access Control (MAC) layer analysis into two separate enti- ties: the resource reservation and the distributed channel access, of which only the former is performed by the network. A periodical, semi static-resource reservation scheme, based on a shared resource pool, was identified as the key to address the communication pattern requirements and to minimize the network involvement. A slotted and periodical channel organization pattern is proposed, which allows the scheduling to be treated as a TDMA-like sys- tem, wherein slots are distributed in both time and frequency. Two different approaches are then considered for distributed channel access: Optical Or- thogonal Codes (OOC) which performs is according to an enhanced random mechanism, and Self-Organizing TDMA (STDMA) , which exploits the knowl- edge of concurrent users’ transmission patterns. The effect of the proposed channel configuration, and channel access algorithms is evaluated analytically and by means of simulation. The cellular V2V mechanism proposed in this thesis enables cross-cell broad- cast, for in-band as well as out-of-band deployment. The flexible channel struc- ture allows coexistence with 802.11 p, which proves challenging due to the substantially different channel access techniques. It is shown that OOC can outperform 802.11 p while only being marginally affected by the half duplex impairment introduced by the time / frequency disposition of transmission i ii slots, but its performance degrades with increasing channel load because of its blind access scheme. STDMA, on the other hand, allows for more stable performance, but its re-reservation mechanism is more significantly affected by losses due to half duplex, thus requiring modifications to adapt to the pro- posed channel structure. CONTENTS 1 introduction 1 1.1 The connected vehicle . 1 1.1.1 The Car-2-Car Communications Consortium approach . 2 1.1.2 The 3rd Generation Partnership Project approach . 3 1.1.3 The Internet of Things approach . 4 1.1.4 Harmonizing the different approaches . 5 1.2 Methodology . 6 1.3 Applicability . 7 1.4 Technology overview . 8 1.4.1 Packet types . 8 1.4.2 Frequency bands allocation . 9 1.4.3 Transmission technology: 802.11 p .............. 10 1.5 Objective and Contributions . 10 1.6 Publications . 12 1.7 Overview of the thesis . 13 2 state of the art 15 2.1 Projects . 15 2.1.1 European projects . 15 2.1.2 US Projects . 17 2.2 Business perspective . 18 2.3 State of the Standard . 19 2.3.1 Introduction to LTE ...................... 19 2.3.2 Proximity Services . 21 2.3.3 LTE -based V2X ......................... 25 2.3.4 The PC 5 Sidelink Interface . 26 2.4 State of the research . 28 2.4.1 MAC Algorithms for V2X ................... 28 2.4.2 LTE -based techniques for V2X ................ 36 3 analysis and problem statement 41 3.1 Service requirements and challenges . 41 3.2 Resource reservation . 44 3.2.1 Cross-cell wide area resource reservation . 46 3.2.2 Timeline of propositions . 47 3.2.3 eMBMS-like resource reservation . 48 3.2.4 Sidelink-based resource reservation . 50 3.2.5 Synchronization . 52 3.2.6 Resource pool partitioning . 53 3.3 Distributed Scheduling . 56 3.4 Optical Orthogonal Codes (OOC) ................... 57 3.5 Self-Organizing TDMA ......................... 58 3.5.1 Related Work . 58 3.5.2 Protocol description . 59 3.5.3 Considerations on slot reuse . 68 3.6 Protocol extensions for STDMA over LTE -V2X ........... 69 3.6.1 OSTDMA ............................ 69 iii iv Contents 3.6.2 SH-STDMA ........................... 70 3.7 Congestion Control . 71 4 modeling 75 4.1 Static Evaluation . 75 4.1.1 OOC over LTE Sidelink: analytical performance evaluation 75 4.1.2 OOC vs 802.11 p: analytical performance comparison . 82 4.1.3 Self-Organizing TDMA : analytical performance evaluation 84 4.1.4 Simulator . 90 4.1.5 Static evaluation by simulation . 93 4.2 Dynamic Evaluation . 93 4.2.1 Highway configuration and mobility model . 94 4.2.2 Channel model . 95 4.2.3 Dynamic evaluation metrics . 97 5 results 99 5.1 Static Evaluation: results . 99 5.1.1 OOC over LTE Sldelink: analytical performance results . 99 5.1.2 OOC vs 802.11 p: analytical performance comparison re- sults . 104 5.1.3 Self-Organizing TDMA : analytical performance results . 106 5.1.4 Static analysis by simulation: results . 109 5.2 Dynamic Evaluation: results . 113 5.2.1 Dynamic evaluation: results for 240 veh/km . 114 6 conclusion and perspectives 119 6.1 Concluding remarks . 119 6.2 Perspectives . 121 Appendices 123 a prose channel access 125 a.1 Sidelink frequency allocation . 125 a.2 Direct Discovery . 125 a.2.1 Resource Allocation for Direct Discovery . 126 a.3 Direct communications . 126 a.4 Procedures for Sidelink Transmissions . 127 a.4.1 Transmission mode 1 (Scheduled Resource Allocation) . 127 a.4.2 Transmission Mode 2 (Autonomous resource selection) . 128 b version française 129 b.1 Résumé . 129 b.2 Introduction . 130 b.2.1 Le véhicule connecté . 130 b.2.2 Méthodologie . 131 b.2.3 Applicabilité . 132 b.2.4 Panorama technologique . 133 b.2.5 Objectifs et contributions . 134 b.2.6 Publications . 136 b.3 État de l’art . 137 b.3.1 État du standard . 137 b.3.2 Perspective business . 141 b.4 Analyse et problématique . 141 b.4.1 Exigences de service et défis . 141 Contents v b.4.2 Réservation des ressources . 142 b.4.3 Ordonnancement distribué . 144 b.4.4 Codes Optiques Orthogonaux ................ 144 b.4.5 Self-Organizing TDMA .................... 145 b.4.6 Extensions protocolaires pour STDMA en LTE -V2X . 146 b.5 Modélisation . 148 b.5.1 Évaluation statique . 148 b.5.2 Évaluation dynamique . 151 b.6 Résultats . 153 b.6.1 Évaluation statique: résultats . 153 b.6.2 Évaluation dynamique: résultats . 154 b.7 Conclusion et perspectives . 155 b.7.1 Remarques finales . 155 b.7.2 Perspectives futures . 156 7 acronyms 159 8 bibliography 165 LIST OF FIGURES Figure 1 Connectivity offered by Long Term Evolution (LTE) plus LTE -Vehicle to Everything (V 2X) .............. 7 Figure 2 Single hop broadcast communications . 8 Figure 3 Frequency allocation plans for ITS-G 5 in the EU and DSRC in the USA . 9 Figure 4 LTE Downlink (DL) air interface nomenclature . 20 Figure 5 ProSe architectural extension - adapted from [ 44 , § 4.2] . 22 Figure 6 Resource Allocation in time/frequency domain - Sub- frame and Resource Block pools . 24 Figure 7 Example of Sidelink (SL) channel structure for transmis- sion mode 2 .......................... 25 Figure 8 LTE V2X reference architecture for non-roaming scenario 26 Figure 9 Comparison of LTE operation mode . 43 Figure 10 Safety Broadcast Area ....................