ITU-R and 3GPP: Use of IMT for Cellular-Vehicle-to-Everything Applications
ITU-R WP5D is working on a preliminary draft report titled, “The use of the Terrestrial Component of IMT for [Cellular-Vehicle-to-Everything] Application.”
When completed (TBD), the report will address the perceived mutual relationship between IMT (International Mobile Telecommunications) technologies and Cellular-Vehicle-to-Everything (C-V2X) as a specific application and elements of functions in IMT technologies that are used to realize C-V2X applications.
Vehicle to everything (V2X) is a term that refers to high-bandwidth, low latency and highly reliable communication between a broad range of transport and traffic-related sensors. Many pundits and cheerleaders say that 5G mobile networks will be key to providing connectivity for vehicle to vehicle (V2V) and vehicle to infrastructure (V2I) communications. Others say that the 4G-LTE V2X sidelink will do just fine.
Also, there are two different types of V2X systems – one based on IEEE 802.11 standards and another (cellular) based on 3GPP specifications. That’s illustrated in this chart:
The focus of this article is on the Cellular-V2X system, previously developed by 3GPP and now via the aforementioned new draft ITU-R report.
The future ITU-R report will provide details and an overview on: Usage of IMT technology, Relationship between IMT and C-V2X, Characteristics and Capabilities supported by IMT, and Case Studies associated with C-V2X for the various scenarios including eMBB, mMTC, and URLLC of terrestrial component of IMT.
IMT usages relevant to vehicle communication are also indicated in the ITU-R M.2445 “ITS usage” report.
The C-V2X applications [described in the 3GPP Release 16 specifications], referred to as Vehicle-to-Everything (V2X), contain the following four different types:
– Vehicle-to-Vehicle (V2V)
– Vehicle-to-Infrastructure (V2I)
– Vehicle-to-Network (V2N)
– Vehicle-to-Pedestrian (V2P)
Utilizing 5G to enhance automotive safety was a focus area for 3GPP Release 16. Release 14 C-V2X introduced a 4G-LTE sidelink (V2V, V2I, V2P) to support basic safety use cases. Release 16 builds on Release 14/15 by introducing a NR-based sidelink that will enable new advanced safety use cases while also paving the path for autonomous driving. Release 16 supports reliable and efficient multicast communication based on HARQ feedback and uses distance as a new dimension at the physical layer, which enables “on-the-fly” multicast groups based on distance and applications.
Relevant ITU-R Recommendations and Reports:
Recommendation ITU-R M.1890 Operational radiocommunication objectives and requirements for advanced Intelligent Transport Systems
Recommendation ITU-R M.2083 IMT Vision – Framework and overall objectives of the future development of IMT for 2020 and beyond
Recommendation ITU-R M.2084 Radio interface standards of vehicle-to-vehicle and vehicle-to-infrastructure two-way communications for Intelligent Transport System applications
Recommendation ITU-R M.2121 Harmonization of frequency bands for Intelligent Transport Systems in the mobile service
Report ITU-R M.2228 Advanced intelligent transport systems (ITS) radiocommunications
Report ITU-R M.2441 Emerging usage of the terrestrial component of International Mobile Telecommunication (IMT)
Report ITU-R M.2444 Examples of arrangements for Intelligent Transport Systems deployments under the mobile service
Report ITU-R M.2445 Intelligent transport systems (ITS) usage
Handbook on Land Mobile (including Wireless Access) – Volume 4: Intelligent Transport Systems
[Editor’s note: More references to be added]
ITU-R Report: U.S. Experience on the use of terrestrial IMT systems in frequency bands below 1 GHz
Draft New Report M.[IMT.EXPERIENCES] – Annex 6 U.S.A
SOURCE: U.S. via FCC
On March 17, 2010, the FCC released The National Broadband Plan, establishing a roadmap for initiatives to stimulate economic growth, spur job creation and boost America’s capabilities in education, health care, homeland security and more. The plan includes sections focusing on economic opportunity, education, health care, energy and the environment, government performance, civic engagement and public safety. The Plan fulfilled a Congressional mandate to ensure every American has “access to broadband capability,” including a detailed strategy for achieving affordability and maximizing use of broadband. One of the key elements of the plan is ensuring efficient allocation and use of government-owned and government-influenced assets. The Plan recommended making an additional 500 MHz of spectrum newly available for broadband within 10 years, of which 300 MHz should be available for mobile use within five years. In order to achieve this goal, the FCC established principles to:
– Enable incentives and mechanisms to repurpose spectrum to more flexible uses. Mechanisms include incentive auctions, which allow auction proceeds to be shared in an equitable manner with current licensees as market demands change. These would benefit both spectrum holders and the American public. The public could benefit from additional spectrum for high-demand uses and from new auction revenues. Incumbents, meanwhile, could recognize a portion of the value of enabling new uses of spectrum. For example, this would allow the FCC to share auction proceeds with broadcasters who voluntarily agree to use technology to continue traditional broadcast services with less spectrum.
– Ensure greater transparency of spectrum allocation, assignment and use to foster an efficient secondary market.
– Expand opportunities for innovative spectrum access models by creating new avenues for opportunistic and unlicensed use of spectrum and increasing research into new spectrum technologies.
In 2014, the FCC adopted a Report and Order for Incentive Auctions. The incentive auction is a new tool authorized by Congress to help the Commission meet the Nation’s accelerating spectrum needs. Broadcasters were given the unique financial opportunity in the “reverse auction” phase of the incentive auction to return some or all of their broadcast spectrum usage rights in exchange for incentive payments. By facilitating the voluntary return of spectrum usage rights and reorganizing the broadcast television bands, the FCC could recover a portion of ultra-high frequency (“UHF”) spectrum for a “forward auction” of new, flexible-use licenses suitable for providing mobile broadband services. Payments to broadcasters that participate in the reverse auction can strengthen broadcasting by funding new content, services, and delivery mechanisms. And by making more spectrum available for mobile broadband use, the incentive auction will benefit consumers by easing congestion on the Nation’s airwaves, expediting the development of new, more robust wireless services and applications, and spurring job creation and economic growth.
The broadcast incentive auction itself comprised of two separate but interdependent auctions – a reverse auction, which will determine the price at which broadcasters will voluntarily relinquish their spectrum usage rights; and a forward auction, which will determine the price companies are willing to pay for flexible use wireless licenses. The lynchpin joining the reverse and the forward auctions is the “repacking” process. Repacking involves reorganizing and assigning channels to the remaining broadcast television stations in order to create contiguous blocks of cleared spectrum suitable for flexible use. In order to be successful, each of the components must work together. Ultimately, the reverse auction requires information about how much bidders are willing to pay for spectrum licenses in the forward auction; and the forward auction requires information regarding what spectrum rights were tendered in the reverse auction, and at what price; and each of these depend on efficiently repacking the remaining broadcasters.
The reverse and forward auctions was integrated in a series of stages. Each stage will consist of a reverse auction and a forward auction. Prior to the first stage, the initial spectrum clearing target is determined. Broadcasters indicate through the pre-auction application process their willingness to relinquish spectrum usage rights at the opening prices. Based on broadcasters’ collective willingness, the initial spectrum clearing target will be set at the highest level possible (up to 126 megahertz of spectrum) without exceeding a pre-determined national aggregate cap on the interference between wireless providers and TV stations (“impairments”) created when TV stations must be assigned to the wireless band. Under this approach, the auction system will establish a band of wireless spectrum that is generally uniform in size across all markets. Then the reverse auction bidding process will be run to determine the total amount of incentive payments to broadcasters required to clear that amount of spectrum.
The forward auction bidding process will follow the reverse auction bidding process. If the “final stage rule” is satisfied, the forward auction bidding will continue until there is no excess demand, and then the incentive auction will close. If the final stage rule is not satisfied, additional stages will be run, with progressively lower spectrum targets in the reverse auction and less spectrum available in the forward auction. The final stage rule is a set of conditions that must be met in order to close the auction at the current clearing target; failure to satisfy the rule would result in running a new phase at the next lowest clearing target.
The FCC’s central objective in designing this incentive auction is to harness the economics of demand for spectrum in order to allow market forces to determine its highest and best use. We are also mindful of the other directives that Congress established for the auction, including making all reasonable efforts to preserve, as of the date of the passage of the Spectrum Act, the coverage area and population served of remaining broadcast licensees. The auction affords a unique opportunity for broadcasters who wish to relinquish some or all of their spectrum rights, but we emphasize that a broadcaster’s decision to participate in the reverse auction is wholly voluntary. In the descending clock auction format we chose, for example, a broadcaster need only decide whether it is willing to accept one or more prices offered to it as the reverse auction proceeds; if at any point the broadcaster decides a price is too low, it may drop out of the reverse auction. No station will be compensated less than the total price that it indicates it is willing to accept.
The FCC also recognizes the importance of broadcasters that choose not to participate in the reverse auction. To free up a portion of the UHF spectrum band for new, flexible uses, Congress authorized the Commission to reorganize the broadcast television spectrum so that the stations that remain on the air after the incentive auction occupy a smaller portion of the UHF band. The reorganization (or “repacking”) approach we adopted will avoid unnecessary disruption to broadcasters and consumers and ensure the continued availability of free, over-the-air television service.
Ultimately, our actions will benefit consumers of telecommunications services. While minimizing disruption to broadcast television service, we seek to rearrange the UHF spectrum in order to increase its potential to support the changing needs of 21st Century consumers. We recognize that the same individuals may be consumers of television, mobile broadband – using both licensed and unlicensed spectrum – and other telecommunications services. To benefit such consumers, and consistent with the framework of the Spectrum Act, we have strived for balance in our decision-making process between television and wireless services, and between licensed and unlicensed spectrum uses.
FCC adopted a “600 MHz Band Plan” for new services in the reorganized UHF spectrum. By maximizing the spectrum’s value to potential bidders through features such as paired five megahertz “building blocks,” the Band Plan will help to ensure a successful auction. By accommodating variation in the amount of spectrum we recover in different areas, which depends on broadcaster participation and other factors, the Band Plan will ensure that the repurposing of spectrum for the benefit of most consumers nationwide is not limited by constraints in particular markets. The Band Plan will promote competition and innovation by creating opportunities for multiple license winners and for future as well as current wireless technologies. Because it is composed of a single band of paired spectrum blocks only, our Band Plan also simplifies the forward auction design. We adopt for new licensees flexible-use service rules, and technical rules similar to those governing the adjacent 700 MHz Band, an approach that should speed deployment in the 600 MHz band. Devices will be required to be interoperable across the entire new 600 MHz Band.
The FCC concluded that the 600 MHz Band Plan we adopt best supports our central goal of allowing market forces to determine the highest and best use of spectrum, as well as our other policy goals for the incentive auction, including the Commission’s five key policy goals for selecting a band plan. The Band Plan enhances the economic value and utility of the repurposed spectrum by enabling two-way (paired) transmissions throughout this well-propagating “coverage band.” This approach also simplifies auction design by offering only a single configuration – paired blocks – which allows for maximum interchangeability of blocks, and enables limited market variation, thus avoiding a “least common denominator” problem. It also provides certainty about the operating environment for forward auction bidders by establishing guard bands between television and wireless services in order to create spectrum blocks that are reasonably designed to protect against harmful interference. Further, the 600 MHz Band Plan promotes competition. By offering only paired blocks in a single band, and by licensing on a Partial Economic Area (“PEA”) basis, the 600 MHz Band Plan will promote participation by both larger and smaller wireless providers, including rural providers, and encourage new entrants. Finally, the 600 MHz Band Plan, composed of a single, paired band, promotes interoperability and international harmonization.
The 600 MHz Band Plan we adopt consists of paired uplink and downlink bands offered in 5 + 5 megahertz blocks. The uplink band will begin at channel 51 (698 MHz), followed by a duplex gap, and then the downlink band. We will license the 600 MHz Band on a geographic area license basis, using PEAs. Further, we will accommodate market variation: specifically, we will use the 600 MHz Band Plan in all areas where sufficient spectrum is available; and in constrained markets where less spectrum is available, we may offer fewer blocks, or impaired blocks, than what we offer generally in the 600 MHz Band Plan. Finally, we establish technically reasonable guard bands to prevent harmful interference and to ensure that the spectrum blocks are as interchangeable as possible.
Because the FCC did not know the exact number of blocks licensed or their frequencies until the incentive auction concludes, the 600 MHz Band Plan we adopted represents a framework for how to license the repurposed spectrum. The Technical Appendix sets forth each of the specific 600 MHz Band Plan scenarios based on the number of television channels cleared; ultimately, the repurposed spectrum will be licensed according to one of these scenarios.
The FCC noted that offering downlink-only blocks in the 600 MHz auction may undermine competition. Because providers must pair downlink-only blocks with existing spectrum holdings, new entrants would not be able to use downlink-only blocks, thus limiting their utility. In contrast, offering paired spectrum blocks will benefit all potential 600 MHz Band licensees. Further, offering downlink-only blocks would further complicate the auction design without a commensurate benefit. As explained above, downlink-only blocks are less valuable than paired blocks to bidders, and offering both paired and unpaired blocks would introduce additional differences among licenses in the forward auction and increase the amount of time the auction takes to close.
Finally, our all-paired band plan generally has nationally consistent blocks and guard bands, which will promote interoperability. In contrast, offering downlink-only blocks could exacerbate interoperability concerns by separating the 600 MHz Band into two bands. If we license both unpaired and paired blocks, we would expect that the industry standards body would create separate bands for the paired blocks and unpaired blocks, as it has done previously. If the 600 MHz Band were split into two separate bands, then some devices could support part, but not all, of the Band. Concerns were also raised over the potential for wireless carriers using downlink-only blocks to configure their networks so as to create barriers to roaming. Limiting the auction to paired blocks will help to ameliorate these concerns. It will also promote international harmonization, and in particular, should help to address cross-border issues with Canada and Mexico.
Repurposing for Mobile Use:
On 18 January 2017, the auction satisfied both of the conditions of the final stage rule, assuring that the auction will close in Stage 4. At $19.8 billion in gross revenue for 70 MHz of spectrum, the incentive auction is among the highest grossing auctions ever conducted by the FCC. The auction created a first-of-its-kind market for repurposing commercially-held spectrum licenses for new uses. The model is part of the foundation of the future of U.S. spectrum allocation and use policy designed for 21st century realities. The US incentive auctions started in March 2016 and has satisfied the rules for the final stage which means that 84 MHz (614-698 MHz) will be cleared from broadcasting including 70 MHz of licensed spectrum and 14 MHz for unlicensed.
Frequency arrangement from US incentive auction:
Following the conclusion of the incentive auction, the transition to the reorganized UHF band will be as rapid as possible without causing unnecessary disruption. Television stations that voluntarily turn in their licenses or agree to channel share must transition from their pre-auction channels within three months of receiving their reverse auction payments. The time required for stations reassigned to a new channel to modify their facilities will vary, so we will tailor their construction deadlines to their situations. This approach will ensure that stations transition as quickly as their circumstances allow, and allow coordination of deadlines where, for example, one station must vacate a channel before another can begin operating on its new channel. No station will be allowed to operate on a channel that has been reassigned or repurposed more than 39 months after the repacking process becomes effective. In other words, the repurposed spectrum will be cleared no later than 39 months after the effective date. Most new licensees should have access to 600 MHz spectrum well before then. Consistent with Congress’s mandate, we also establish procedures to reimburse costs reasonably incurred by stations that are reassigned to new channels, as well as by multichannel video programming distributors to continue to carry such stations.
As the U.S. Congress recognized, the incentive auction and the transition that follows require coordination with our cross-border neighbors, Canada and Mexico. Because of these common borders, the Commission has established processes and agreements to protect television and wireless operations in border areas from harmful interference. The FCC staff has used these processes to fully inform Canadian and Mexican officials regarding the incentive auction and, beginning in 2013, formed technical groups to meet routinely to plan for harmonious use of the reorganized UHF band following the incentive auction. Commission leadership has supplemented these efforts, meeting with their Canadian and Mexican counterparts to emphasize the need for and mutual benefits of harmonization. We are confident that the long and successful history of close cooperation with Canada and Mexico regarding the use of radio spectrum along our common borders will continue before, during, and after the incentive auction.
The recovery of the 700 MHz Band was made possible by the conversion of television broadcasting from the existing analog transmission system to a digital transmission system. Because the digital television (DTV) transmission system is more spectrally efficient than the analog system, less spectrum will be needed for broadcast television service after the transition to DTV on channels 251 is complete. The USA which switched-off its analogue transmissions in 2009, and was the first Administration to relocate the channels 52 to 69 to advanced wireless service.
The successful auction of the 700 MHz band has facilitated a nationwide roll-out of IMT (LTE) deployments, including establishing valuable spectrum for public safety uses. The U.S. 700 MHz band plan divides the 698-806 MHz frequency range into a lower 700 MHz portion and an upper 700 MHz portion. The final band plan is available at: http://wireless.fcc.gov/auctions/data/bandplans/700MHzBandPlan.pdf
To enable operability along border areas, the FCC has worked through bilateral coordination processes with its neighbours to address issues with variation in adopted band plans. The U.S. and APT FDD band plans are incompatible in their assignment of uplink and downlink spectrum therefore careful coordination of spectrum is required along the border areas. Due to overlapping base and mobile transmission of one band plan with base and mobile receiving frequencies of the other band plan, several interference scenarios can be found along the border.
According to a July 2012 survey, the U.S. 700 MHz ecosystem has grown rapidly to include 193 LTE device products including Modules for M2M, notebooks, phones, routers for hotspots, tablets and USB modems supported by over 18 manufacturers. 3GPP defines a number of bands in 700 MHz: Band 12: (Lower 700 MHz) 699 MHz-716 MHz /729 MHz-746 MHz; Band 13: (Upper C 700 MHz) 777 MHz-787 MHz /746 MHz-756 MHz; Band 14: (Upper D 700 MHz) 788 MHz798 MHz /758 MHz-768 MHz; Band 17: (Lower B, C 700 MHz) 704 MHz-716 MHz /734 MHz-746 MHz.