A Progressive Single Channel Reservation Scheme for URLLC in Unlicensed Band

Sheng Shih Wang, Wei Kang Chen, Yu Cheng Chen, Mu Cheng Chiang, Li Ling Huang, Shiann Tsong Sheu

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


To tackle the problem of transmission uncertainty for ultra-reliable and low-latency communication (URLLC) in unlicensed band, existing studies have proposed many channel reservation based schemes categorized into single-channel reservation and multi-channel reservation schemes. The schemes integrate the full duplex radio and orthogonal busy tone technologies to reserve URLLC channel. URLLC channel reservation is accomplished by all URLLC devices continuously sending busy tones on the URLLC channel. Compared to the multi-channel reservation scheme, the single-channel reservation scheme is more friendly to the heterogeneous system, such as Wi-Fi, but it generates an unsatisfactory probability of successful channel reservations as it is difficult to find the common single channel for all URLLC devices especially when the traffic load of unlicensed band is above a certain level. This paper proposes a progressive single channel reservation (P-SCR) scheme to promote the success probability of channel reservation by relaxing simultaneousness restriction of URLLC channel reservation. The P-SCR scheme allows user equipment to reserve the common URLLC channel in a progressive manner and introduces an advanced preparation time to improve channel utilization and probability of successful URLLC channel reservations. The performance evaluation results showed that the proposed P-SCR scheme obviously outperforms the existing single- and multi-channel reservation schemes in terms of the probability of successful channel reservation.

Original languageEnglish
Title of host publication2021 IEEE 94th Vehicular Technology Conference, VTC 2021-Fall - Proceedings
PublisherInstitute of Electrical and Electronics Engineers Inc.
ISBN (Electronic)9781665413688
StatePublished - 2021
Event94th IEEE Vehicular Technology Conference, VTC 2021-Fall - Virtual, Online, United States
Duration: 27 Sep 202130 Sep 2021

Publication series

NameIEEE Vehicular Technology Conference
ISSN (Print)1550-2252


Conference94th IEEE Vehicular Technology Conference, VTC 2021-Fall
Country/TerritoryUnited States
CityVirtual, Online


  • 5G
  • busy tone
  • channel reservation
  • ultra-reliable and low latency communication (URLLC)


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