- The geo-positioning technology company has petitioned the FCC for access to the 902-928 MHz band, which creates potentially significant disruption for other technologies using that band, including UHF RFID, Z-Wave and LoRa.
- The company claimed—in its response to public comments addressed to the commission— that the petition was important for public health, and that it had reached out to amateurs and engineers whose work could be affected.
Terrestrial GPS technology company NextNav has responded to initial comments from members of the tech industry, over its Federal Communication Commission (FCC) petition request for access to the lower 900 MHz band.
The NextNav petition was filed in April to the FCC to expand the power level, bandwidth and priority of its licenses in the 902 to 907 and 918 to 928 MHz bands in the United States—a bandwidth currently in use by UHF RFID, Z-Wave, LoRa and numerous other wireless technologies. Additionally, NextNav proposes to use 5G connectivity over the relatively low bandwidth.
Thus far, there are 907 posted responses to the petition, many from industry associations, technology firms, end users, as well as amateur and hobbyist developers. While the initial responses period closed on Sept. 5, follow-up comments are being accepted until Sept. 20.
The majority indicated the change being requested would adversely affect the “Part 15” devices that already use the lower 900 MHz band NextNav is seeking access to, cutting off services that industries such as healthcare, defense, aerospace, retail and tolling rely on.
Arguing Urgency for Terrestrial PNT
NextNav claims there is an urgent need for a terrestrial position, navigation and timing, (TPNT) system to complement and back-up existing GPS. The plan would be to enhance wireless emergency (E911) location accuracy, but also provide consumer 5G access over the same band that is being used by other technologies.
NextNav referred RFID Journal’s requests for comment to its Sept 5-filed 55-page FCC response.
The company argues its service is imperative based on a need for a backup to GPS in the event of a disruption. “Rationalizing the lower 900 MHz band not only puts the lower 900 MHz band to its highest and best use, but also can require the licensee—NextNav in this case—to enable a TPNT complement and backup to GPS that the United States has long identified as a public interest imperative,” NextNav wrote in its FCC response.
At least two agencies commented to the FCC in favor of granting the petition for terrestrial PNT service over the lower 900 MHz band. The Fire Chief’s Association of Massachusetts and San Bernadino County Fire Protection District similarly wrote that GPS signals can be degraded (for instance by tall buildings in cities), leading to potential sporadic GPS based location. Both said that having a consistent x/y signal that penetrates buildings would support emergency response.
5G Services
Beyond emergency response navigation, NextNav is seeking to further use the band for 5G services, a “reconfiguration of the band results in 15 megahertz of low-band spectrum for the deployment of wireless broadband internet access services,” the company stated.
It also indicated that when it comes to government agencies that use technologies such as RFID, “while considerable outreach remains to be done, it appears that federal incumbents have a small footprint in the band, mostly confined to a handful of military bases.”
Additionally, NextNav expects these uses can continue to operate in the lower 900 MHz band, “although there will not be a one-size-fits-all solution.”
From Agriculture to Healthcare to Defense
In the meantime, dozens of technologies are using the bandwidth in question, for everything from smart lighting, agriculture management and factory work-in-progress, to inventory and supply chain tracking of products, including pharmaceuticals and healthcare devices.
According to a response that standards associations AIM Global and the RAIN Alliance submitted, there are more than 200 billion RAIN RFID tag chips shipped worldwide to date, and about 40 percent of them (80 billion) are deployed in the U.S. Such UHF RFID systems are widely used for logistics as well as in automotive and aviation, smart manufacturing, food safety, energy and smart cities.
Since 1995, the commission has upheld an “equitable balance” between the needs of communication service providers and those of the Part 15 users and manufacturer. That means devices cannot cause harmful interference with others. That would change with the NextNav petition, granting the navigation system dominance in a hierarchy above other systems.
Questioning Interference
The geopositioning system company said more study would be needed to identify interference concerns. “The point is simply that the interaction of many different kinds of transmitters and receivers and use cases during a time of rapid innovation defies easy generalization and merits further attention in a notice of proposed rulemaking,” they wrote to the commission.
The statement claims that “RFIDs [sic] are designed to incorporate a range of interference mitigation strategies, and, indeed, an ostensibly interfering signal can sometimes cause RFID performance to improve,” adding that, “the additional noise helps activate passive RFID tags and close otherwise marginal links.”
However, the RAIN Alliance and AIM Global officials indicated in their comments that they have performed a technical analysis of the interference that would be created if devices operating in accordance with the technical rules proposed by NextNav were introduced into the lower 900 MHz band.
In fact, the RFID associations argued that the introduction of NextNav’s PNT or 5G devices into the Lower 900 MHz Band, based on lab-based testing would be likely to severely disrupt, “if not force the termination of, the operations of RAIN RFID systems across the United States.”