Page 60 - ITU Journal Future and evolving technologies Volume 3 (2022), Issue 2 – Towards vehicular networks in the 6G era
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ITU Journal on Future and Evolving Technologies, Volume 3 (2022), Issue 2




                                                                                            Update
                            Source                                                       Destination
                                         4                 3  2                     1
                                                       V2V
                                    V2R        v                      traffic hole     V2R

                          Sensor                 L 1                          L 2          RSU

                                   Fig. 1 – Scenario of update delivery under traf ic light in vehicular networks


          The  second  vehicle  is  stopped  by  the  red  light  and  a   allowing for transmission of multimedia data such as ve‑
          traf ic  hole  appears  between  the   irst  and  the  second   hicle  images  for  use  in  machine  learning‑related  appli‑
          vehicle,  blocking  the  V2V  data  transmissions  and   cations  [13,  12].  6G  networks  allow  for  the  introduc‑
          increasing  the  delivery  delay  of  the  second  update.   tion of the Internet of Things or other real‑time applica‑
          While the second vehicle carrying the second update is   tion  services,  such  as    icial  intelligence  and  big  data
          waiting at the red light, the third vehicle catches up and   computing  applications  [14].  With  speeds  up  to  1Tbps
          forwards the third update to reduce its delay.       and packet delays below 100  /  , 6G networks can meet
                                                               quality  of  service  guarantee  requirements  [15].  In  or‑
          In this paper, we investigate the in luence of traf ic lights   der  to  meet  high  requirements  of  6G  networks  such  as
          on  data  delivery  in  vehicular  networks  using  the  met‑
                                                               high  reliability  and  high  security  in  a  dynamic  and  hete‑
          ric of Age of Information (AoI). Since traf ic lights block
                                                               rogeneous vehicular network, Zhang et al.  [16] propose
          V2V data delivery, we discuss the optimal generation rate
                                                               a novel Weight‑Based Ensemble machine Learning Algo‑
          at  the  source  by  considering  the  trade‑off  between  the   rithm (WBELA) to identify abnormal messages of vehicu‑
          AoI and transmission cost.  A red light stops the vehicles   lar Controller Area Network (CAN) bus network.  Emplo‑
          carrying  the  updates  and  increases  the  updates’  delays.   ying  machine  learning  into  6G  vehicular  networks  to
          Meanwhile,  the  vehicles  moving  behind  could  catch  up   support  vehicular  application  services  is  being  widely
          with the waiting vehicles in forwarding the new updates,   studied  and  a  hot  topic  for  the  latest  research  work  in
          and the old updates at the traf ic light will lose their con‑   the  literature.  In  vehicular  networks,  network  entities
          tributions on AoI. Increasing the generation rate can re‑   need  to  make  decisions  to  maximize  network  per-
          duce  the  AoI,  but  also  increase  the  number  of  such  old   formance  under  uncertainty.  Mekrache  et  al.  [14]
          updates at the red light.  We also consider the transmis‑   provide a comprehensive  review  of  research  work  that
          sion cost (energy consumed) [7],  as increasing the gene‑   integrated   reinforcement  and  deep  reinforcement
          ration  rate  can  also  increase  the  cost.  Therefore,  gene‑   learning algorithms for vehicular networks management
          ration rate control at the sensor source should consider   with  an  emphasis  on  vehicular  telecommunications
          the    luence  of    ic  lights  on  the  data  transmissions.   issues.
          We also propose a Total Average Cost aware generation
          rate Algorithm (TACA) for deciding the generation inter‑
          val time at the sensor source.  Our intensive simulations   There  are  many  vehicular  applications  based  on  sen‑
          verify the proposed algorithm and evaluate the in luence   sing  and  communications  between  vehicles.  Ahn  et  al.
          of the traf ic lights on AoI.                        [17] present the Road Information Sharing Architecture
                                                               (RISA),  a  distributed  approach  to  road  condition  detec‑
          The remainder of this paper is organized as follows:  In   tion  and  dissemination  for  vehicular  networks.  Signal‑
          Section 2, we review the most related work.  We discuss   Guru [18] relies solely on a collection of mobile phones
          the system model and the traf ic hole problem in Section   to detect and predict a traf ic signal’s schedule.  For such
          3. We analyze the AoI and transmission cost in Section 4.   an  infrastructure‑less  approach,  multiple  phones  in  the
          We evaluate the ef icacy of the analysis model and the data   vicinity use opportunistic ad‑hoc communications to col‑
          delivery with traf ic lights in Section 5.  The  inal section   laboratively learn traf ic signals’ timing patterns and pre‑
          concludes the paper.                                 dict  their  schedules.  Various  advanced  sensors  (e.g.,  li‑
                                                               dar, radar, camera, etc.) equipped on a representative au‑
          2.   RELATED WORK                                    tonomous vehicle. Due to the intrinsic limitations of these
                                                               sensors, autonomous vehicles are prone to making erro‑
          6G and vehicular networks:  The 6G vehicular network
                                                               neous decisions and causing serious disasters.  Networ‑
          aims to develop a highly dynamic and intelligent system,
                                                               king  and  communication  technologies  can  greatly
          which enables the networks to change the environment
                                                               make up  for  sensor    iciencies,  and  are  more  reliable,
          to  satisfy  various  application  requirements  and  service
                                                               feasible  and  ef icient  to  promote  the  information
          types, such as enhanced Mobile Broadband (eMBB), ultra‑
                                                               interaction,  thereby  improving  autonomous  vehicles’
          Reliable  and  Low‑Latency  Communications  (uRLLCs),
                                                               perception  and  planning  capabilities,  realizing  better
          and  massive  Machine‑Type  Communications  (mMTCs)  vehicle  control,  and  ultimately  greatly  improving  the
          [12]. 6G network transmission can reach speeds of 1Tbps,  security of autonomous vehicles [19].


          48                                 © International Telecommunication Union, 2022
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