Assessment of V2X technologies for safety, system efficiency, and mobility; and assessment of the safest and most efficient use of allocated spectrum to accommodate transportation needs requires transparent, comprehensive, and repeatable test results that assure that the technologies work under normal as well as varying traffic conditions that create “edge-use” cases.
This website will serve as the host for the information on current and future US DOT ITS/V2X communications research and testing activities, including test goals and objectives, test plans and approaches, laboratory and field test data, summaries of key test observations, and program fact sheets and briefings.
The goal of the U.S. DOT’s LTE-V2X Test Program is to examine the radio performance of LTE-V2X technology under challenging, “edge-use case” conditions—the type of conditions that result in some of the most common and fatal crashes. These challenging conditions are not exclusive to transportation. However, because the V2X communications and BSM transmissions are designed to provide 360-degree awareness around a vehicle of the threats and hazards forming on the roadway from nearby vehicles, pedestrians, motorcycles, bicyclists or others, examination of the radio environment—its reliability and availability—is equally as important.
The test team designed scenarios to mimic the type of complex roadway conditions under which the radio or communications technology must perform reliably and consistently in a broadcast, non-networked mode. The radio performance must sustain communications under a variety of conditions, such as when:
A field test scenario spreadsheet was used to structure and organize the various field test runs performed at the large-scale field test site. The spreadsheet is provided below:
Device performance testing verifies that all parameters are set as directed by the software and that the performance of the devices and antennas meets specifications. Results from characterization testing can also provide insights into operational and/or performance trade-offs.
The laboratory testing performed on the LTE-V2X devices included: device characterization, GPS drift assessment, continuity of communications with loss of GPS, and device interoperability testing. Results of these tests are summarized below:
This U.S. DOT large-scale controlled field testing moves beyond the reliance on simulation to collect and present real-world measurements taken under challenging transportation conditions. The large-scale field test set-up will mimic the following use cases:
The data collected from these tests is provided below:
Initial modeling and simulation work helped the test team determine if any adjustments were necessary to the planned field test congestion scenario set-ups. The results from these efforts helped to provide the best understanding of communications performance in the field test environment before going out into the field. In addition, the modeling and simulation identified the necessity of allowing the congestion cloud to settle into its ongoing SPS performance before starting field test runs.
A summary of these activities is provided below:
The majority of the LTE-V2X testing has been completed and a summary of observations on device performance, interference, and performance within the 30 MHz is provided below:
The USDOT tested Dedicated Short-range Communications (DSRC) technology extensively over several years, including the impact of sharing the band with unlicensed devices, impact of out of band emissions (OOBE) and interference from unlicensed devices operating in adjacent channels.
As a result of these activities, several technical reports were produced and made available to the public. You can find these reports on the Safety Band website.
Please explore this site for a more detailed description of the program and progress. We will continue to upload relevant program information for public consumption as it becomes available. For inquiries regarding the program, please contact the USDOT Point of Contact below.