- For decades, RAIN RFID and other Part 15 devices have enjoyed transmitting across an unoccupied band with little interference
- NextNav is bringing terrestrial GPS to that bandwidth, if approved by the Federal Communication Commission, which could mean more wireless traffic on the same band
A survey and recent comments by the Federal Communication Commission’s (FCC) chairman show a potential for re-organization of the bandwidth that has been the exclusive domain for UHF RAIN RFID users and other Part 15 devices.
In April 2024, NextNav filed a rulemaking petition with the FCC to realign the 902-928 MHz band that is currently used by RAIN RFID as well as other wireless devices such as LoRa transmissions and Z-wave that could impact transmissions of UHF RAIN RFID and other “Part 15” devices in the U.S. The rule would permit 5G transmissions on that same band. Last summer was the deadline for the FCC to accept community comments about the impact of the rule change.
If the NextNav petition is awarded, the proposed changes could create some crowding of that bandwidth in the U.S., according to a joint statement issued by RFID industry standards organizations RAIN Alliance and AIM Global.
FCC Open to Deregulating any Band
Earlier this month, FCC Chairman Brendan Carr announced that the agency has launched a deregulatory initiative aimed at all of the agency’s existing regulations to review, including broadcast ownership caps. The FCC will consider a Notice of Inquiry exploring alternatives to GPS on March 27. While the notice mentions NextNav, it is broader than the single company and its petition.
As part of the effort, the FCC has opened a new docket titled “In re: Delete, Delete, Delete” in which the agency “seeks comment on every rule, regulation, or guidance document that the FCC should eliminate for the purposes of alleviating unnecessary regulatory burdens.” Carr said that the FCC was acting in direct response to “the Trump Administration’s decision to usher in prosperity through deregulation.”
The 902 to 928 MHz band could be included among these changes which could be a benefit for Part 15 devices as they are currently the least regulated element of the band.
Seeking Priority of 910-928 MHz for Terrestrial GPS
NextNav is a positioning, navigation, timing (PNT) and 3D geolocation technology company. Its petition aimed to expand the power level, bandwidth and priority of its licenses, resulting in new added regulatory requirements. Additionally, the Virginia-based company proposes to use bidirectional 5G connectivity over the lower bandwidth.
The company appealed to the federal independent regulatory agency for rule changes that would enable its terrestrial 3D PNT network for 5G and bidirectional transmissions in the lower 900 MHz band. The system could be used for location mapping and tracking services such as enhanced 911 (E911) communications, which enable first responders to view location information during emergencies even if GPS systems were down.
“This plan offers enormous benefits to the public by creating a complement and backup to GPS, while also unleashing much-needed spectrum for 5G broadband,” NextNav spokesperson Howard Waterman previously stated.
Existing 902-928 Part 15 Devices
Since 1995, the FCC has allowed RAIN RFID operation (as well as other Part 15 devices such as baby monitors and cordless phones and tolling systems) in the designated 902-928 MHz frequency band. Other technologies such as medical devices, smart home equipment and LoRa systems leverage this frequency band under the same unlicensed parameters.
However, manufacturers of such Part 15 devices are not protected against interference from other users and the devices must be designed to use techniques such as frequency hopping to avoid bandwidth crowding. NextNav has requested changed and added regulatory requirements that they systems would have priority over other devices.
NextNav’s Technical Study
NextNav recently released a report that found that transmission blocking from base stations would be minimal for Part 15 devices. It indicated the value of changing the bandwidth rules, by preventing GPS outages during an emergency, outweigh the costs felt by the competing industries using that bandwidth.
Under their analysis, a one-day nationwide GPS outage associated with geo-magnetic storms should occur around once every four years, and a seven-day nationwide outage should occur around once every 25 years. The report’s assumption means that in the last 25 years the country should have experienced roughly six nationwide GPS outages lasting one day, and likely one seven-day outage.
And NextNav has pointed to a Public Policy Polling survey released March 10 that found large majorities of voters see a terrestrial complement and backup to GPS as vital to safeguarding public safety, keeping pace with foreign rivals, protecting U.S. national security, and preserving a strong economy.
But these report has its critiques, led by the U.S. Chamber of Commerce who reacted dubiously about this finding. In its statement, it argued that these benefit would need to be weighed against harm the proposal could inflict on incumbent users of the lower 900 MHz band including RAIN RFID. Chamber officials contend “the report concedes that its analysis ‘focuses on benefits of reconfiguration’ and that such benefits must ‘be weighed against the costs of the reconfiguration in evaluating the benefits of the proposal to society’.”
NextNav Questions Interference Concerns
According to John Kim, NextNav’s technology development VP, for a 5G downlink transmissions to have an impact on a RAIN RFID system, all of the following must be true simultaneously: a 5G base station must be close enough to the RAIN RFID system to cause potential impact and that distance could vary because differing RAIN transmission ranges yield differing interference resiliency.
Kim added that the RAIN system must be conducting an inventory round (in operation), the RAIN RFID system must be operating at a frequency which overlaps with the NextNav proposed downlink band, and the 5G equipment must be transmitting at the same time. He argued that these conditions may not be very likely.
“A simultaneous concurrence of all of the events necessary for 5G signals to produce a real-world impact on RAIN [RFID] is not impossible, but it is highly improbable,” Kim said. In fact he pointed to figures that identify the terrestrial 5G functionality will be statistically minimal “The average UE activity factor on a 5G system in the 902-928 MHz band will be approximately 0.045 percent.”
GS1 US Weighs In
Furthermore, Kim contended interference to RAIN RFID transmissions can come from many different sources, including other nearby RAIN RFID readers and tags, other Part 15 operations, ISM devices, and licensed services in the band.
Those assertions may not ease the concerns for RAIN RFID industry members. Nonprofit standards group GS1 US governs the standards that power RFID technology, and in that role, “GS1 US is sharing information with industry stakeholders regarding the FCC request for comment, and GS1 US will respond to the FCC request for comment. In doing so it will outline the many benefits of the technology,” said Jonathan Gregory, GS1 US’ global standards director.
The RAIN Alliance Radio Regulation team, as well as other Part 15 users, are undertaking their own review of the NextNav released analysis and said they would respond in the future.
NextNav’s Prepares for Expansion
NextNav is already preparing for the proposed change. Last year, the public company invested $50 million following submission of the petition, with potential to expand up to $80 million. It also hired a Verizon executive to lead its strategy for what it called an innovative spectrum solution in the lower 900 MHz band.
The navigation company officials reported that its petitioned rule-change is needed for enhancing national security and public safety through robust and resilient PNT services. And in fact, some U.S. lawmakers have expressed concern about existing GPS system resiliency—President Donald Trump in 2020 signed an executive order on Strengthening National Resilience through Responsible Use of PNT services.
Chairman Carr indicates that the FCC plans to open an inquiry later in March which will explore alternatives to GPS. As the RAIN Alliance noted in a recent blog post: “We see this inquiry as a positive step as it should be possible to find an alternative to GPS that doesn’t cause such severe impacts to other technology deployments including RAIN systems.”
With the proposed rule change, NextNav would have preferential treatment which could result in RFID deployments being shut down. The NextNav report does not address that challenge.
Room for Compromise
NextNav’s company officials reported that they are “committed to working with all incumbents in the band to develop a better understanding of operations, including the frequencies and geographies where the band is in use.”
Kim added that he anticipates the petition to lead to new dialog as “the FCC’s rulemaking process allows us all to engage in these important conversations and we look forward to working together to put this spectrum to the best set of uses.”
In responses to the petition, the RAIN Alliance contended that the rule change could affect “the resilience and efficiency of America’s supply chains, businesses and government agencies.” And because the technology is used as part of global supply chains, the impact would be felt worldwide, added Aileen Ryan, president of the RAIN Alliance.
Chairman Carr indicates that the FCC plans to open an inquiry to explore alternatives to GPS. The NextNav proposed solution would potentially be one alternative, but there are others. “We see this inquiry as a positive step as it should be possible to find an alternative to GPS that doesn’t cause such severe impacts to other technology deployments including RAIN systems,” Ryan said in a recent RAIN Alliance blog.
