Evaluation and Synthesis of Connected Vehicle Communication Technologies (2021)

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

NCHRP 23-10 Evaluation and Synthesis of Connected Vehicle Communications Technologies Fact Sheet: FCC Realignment of 5.9 GHz (December 2020 Update) The National Cooperative Highway Research Program (NCHRP) is supporting a project that provides state DOTs with up to-date information on connected vehicle (CV) communications technologies to help inform policy development, strategic planning, and infrastructure investment decisions. The primary focus is to help explain the impacts of the Federal Communication Commission (FCC)’s efforts to reduce the amount of spectrum in the 5.9 GHz band dedicated to “operations related to the improvement of traffic flow, traffic safety and other intelligent transportation service applications,” realized today through CV applications. The project team of WSP USA and the University of Michigan Transportation Research Institute developed this fact sheet on the implications for state DOTs of the recent actions that will adopt, with only limited modifications, the previously announced Notice of Proposed Rulemaking (NPRM) to reduce the amount of spectrum dedicated to transportation from 75 MHz to only 30 MHz. As part of this action the FCC will establish specific technology requirements within that allocation and open the rest of the spectrum to unlicensed Wi-Fi devices. For more information about the NCHRP project, visit the project web page, or search the TRB website for “NCHRP 23-10”. A recap of FCC activities prior to this update include: • February 6, 2020 - NPRM published in Federal Register as FCC ET Docket No. 19-138 • April 27, 2020 - Comment Period and Reply Comment Period end, with 88% of comments in opposition to the NPRM • October 28, 2020 - FCC releases a draft First Report & Order and related documents for consideration • November 18, 2020 - FCC approved the First Report and Order, Further Notice of Proposed Rulemaking, and Order of Proposed Modification. What Was Approved on November 18, 2020 Three documents were presented and approved at the FCC’s Open Commission Meeting: 1. The First Report & Order (R&O) primarily sets the stage for the revised band plan, which allows unlicensed indoor devices in the lower 45 MHz immediately, and temporarily allows both dedicated short range communications (DSRC) and cellular vehicle to everything (C-V2X) in the upper 30 MHz. Existing DSRC licenses have 1 year following the effective date of the First Report and Order to vacate the lower 45 MHz and relocate to the upper 30 MHz. 2. The Further Notice of Proposed Rulemaking (FNPRM) is the same process as the NPRM that was completed in early 2020 - a document with several questions and requests for comments. In this case a lot of the significant details not covered in the First R&O are included here - such as revised channel alignments, power and antenna specs, output levels for each channel, how to affect change in on-board units (OBUs), co-existence of DSRC and C-V2X, future bandwidth needs, and more. Many of the technical details proposed for the newly reduced 30 MHz band will be decided in a new Report & Order that will result from this FNPRM process. 3. The Order of Proposed Modification (OPM) is a procedure required to modify existing licenses in the band and set basic ground rules for new licenses during this transition period. Forward Looking Timeline: The next step is for the package to undergo minor technical editing, and then on to the Federal Register for publication. This process can take anywhere from two to six weeks. Once it gets published, several process clocks and gates are activated: • Within 30 days of publication, parties can file a protest or petition for reconsideration on the R&O. • At 60 days after publication, the R&O officially goes into effect. At that point, the 1-year clock begins for existing DSRC licenses to vacate the lower 45 MHz. • Details for the FNPRM comment period(s) will be announced in the publication. The current NPRM included 30 days for comment and 30 days for reply comment. • At the conclusion of the FNPRM process, a new R&O will be released and voted on, presumably answering all the outstanding technical questions. Once that gets approved, published, and enacted (60 days after publication), another 2- year clock is proposed to begin whereby the upper 30 MHz must become only LTE C-V2X.

Impacts and Response for State Departments of Transportation Existing DSRC deployments: begin a migratory path to Channel 180 and eventually C-V2X Agencies with roadside units (RSUs) that are currently operating on any portion of the lower 45 MHz should meet with their device vendors and understand what firmware (and possibly hardware) updates will be necessary to migrate to Ch 180. Every vendor and device will likely have a different path toward this change. Under the current timeline this migration should be completed by Spring 2022. Additional time and resources will likely be required for this changeover. There are many unknowns as devices exist in various configurations around the country, and all were designed to operate on seven channels, not one. Agencies with RSUs that are currently operating DSRC only on Ch 180 will potentially have 2-3 years under the current FCC timeline, but would be wise to begin charting a course to switch over to currently available long term evolution (LTE) C-V2X sooner. In all likelihood device vendors will scale-back support for DSRC devices sooner than desired, which may have the unintended consequence of accelerating FCC timelines. Planned V2X deployments: keep moving forward, but emphasize no-regret investments There are many benefits to continued deployment of V2X communications. If your agency is already in the procurement process, consider dual-mode RSUs or LTE C- V2X only. It is recognized that not every agency can change mid-procurement and stopping a project might jeopardize other elements that could bring benefits. Continue to emphasize no-regret elements such as next generation signal controllers, enhanced communications and network architecture, data collection, security, and the potential benefits that can still be garnered through pilot testing and early deployment regardless of radio technology. Once again, device availability and support from vendors may drive this timeline. Impact on applications may vary For DSRC-focused deployments, discuss with your project partners what applications might be compromised given the many unknowns that currently exist with migrating to a single-channel configuration. Likewise, for LTE C-V2X- focused deployments, discuss any concerns related to application interference from unlicensed devices. Over the next year or two we will learn a lot about channel congestion and interference that will likely impact application development and performance. LTE C-V2X device availability, licensing, and testing is evolving: build time and cost into your projects LTE C-V2X devices are still in their infancy and with limited availability. The standards are still unfolding, and deployment experience has been small scale. Likewise, the licensing process remains uncertain (experimental licenses are assumed as of this writing), as is the availability of reliable and affordable test equipment. The industry will benefit from its experience with DSRC but it will take time for best practices to emerge, and new issues to be worked out at scale. DSRC was still experiencing lessons-learned for deployment after 5-7 years. Be prepared to thoroughly respond to the FNPRM and other docket activities There will be a comment and reply comment period following the official publication of the FNPRM, most likely in early 2021. This is an important opportunity for existing deployers to very thoroughly detail the cost of migrating to Ch 180 and/or moving away from DSRC, impacts of the reduction in spectrum to current and planned applications, and potential loss or change in benefits realized by the agency and the users of your system. The FNPRM also includes important questions about proposed transition timelines, seeks comments on the availability of and experiences with LTE C-V2X, and perhaps most importantly, seeks input on whether 30 MHz is sufficient for future V2X applications and if the FCC should consider allocating additional spectrum for ITS. Note that there will also be additional comment windows should there be a petition for reconsideration or other docket actions taken. These are important opportunities to provide the FCC with input about the impacts and implications that are unique to your agency, your users and your environment. NCHRP produces ready-to-implement solutions to the challenges facing transportation professionals. NCHRP is sponsored by the individual state DOTs of the American Association of State Highway and Transportation Officials (AASHTO), in cooperation with the Federal Highway Administration (FHWA). NCHRP is administered by the Transportation Research Board (TRB), part of the National Academies of Sciences, Engineering, and Medicine. Any opinions and conclusions expressed or implied in resulting research products are those of the individuals and organizations who performed the research and are not necessarily those of TRB; the National Academies of Sciences, Engineering, and Medicine; or NCHRP sponsor