The FCC Waived CBRS Sensor Rules for Hurricane Isaias. Its Own Footnote Lists 20 Earlier Waivers.

Twenty. That’s how many earlier orders footnote 16 lists when the FCC’s Wireless Telecommunications Bureau explains why it granted Federated Wireless another emergency waiver of the CBRS sensor rules on October 9 [1]. The list runs from September 2022 to September 25 of this year [1].

This one was for Hurricane Isaias. On the day it was granted, the Hurricane Center’s 4 p.m. advisory had Isaias as a Category 3 storm with winds near 115 mph, expected to come ashore on the western Florida Panhandle that evening [7].

What the FCC granted

The order, DA 26-1095, is four pages, signed by Roger Noel, chief of the Mobility Division [1]. Federated filed its request on October 7 and got an answer two days later [1].

Some background, because the mechanism is the story. The Citizens Broadband Radio Service shares the 3.5 GHz band (3550-3700 MHz) between federal incumbents and commercial users in two lower tiers, Priority Access licensees and General Authorized Access users [1]. An automated coordinator called a Spectrum Access System, or SAS, decides who can transmit where [1]. Networks of sensors called Environmental Sensing Capabilities, or ESCs, listen for federal signals inside Dynamic Protection Areas. When they hear one, the area activates and federal users get priority [1].

Here’s the design choice that matters. The order spells it out: “In the case that an ESC cannot accurately determine whether federal incumbents are active in the band, they must automatically activate the DPAs” [1]. A sensor that loses power or backhaul can’t hear anything, so the system assumes a federal user is there and moves commercial radios out of the way.

Federated asked to be excused from that rule for DPAs East 20 through East 24 and East 3 [1]. It said outages could otherwise force those zones on and cut service to about 10,000 Citizens Broadband Radio Service Devices, or CBSDs, serving what it called millions of customers, from homes and schools to oil and gas companies [1]. Its filing, as the order quotes it, says “[m]any of these customers will be relying on these services to stay apprised about ongoing dangers in the aftermath of the storm” [1].

The Bureau granted it under the second prong of its waiver standard, finding “unique circumstances that make application of the rules inequitable, unduly burdensome, and contrary to the public interest” [1]. Federated’s SASs may now treat those zones as “inactive” [1]. The Bureau also waived a handful of related Part 96 sections on its own motion [1].

The five conditions

The waiver is narrower than “turn the sensors off” [1]:

1. It applies only while a sensor can’t reach Federated’s SASs because of a power or backhaul outage.
2. It ends on October 23, 2026, or when power and backhaul are restored, whichever comes first.
3. Federated must confirm restoration to the FCC, the Department of War and the Navy within three business days.
4. Any extension request has to show the specific steps taken to bring the sensors back, and has to be filed at least three business days before the waiver ends.
5. The ESC operator has to activate the zones immediately if the FCC, NTIA or the Department of War says so.

Those five conditions are not new. The January 23 order for Winter Storm Fern uses the same list, and so does the September 25 order for Tropical Storm Nolo in Hawaii, with only the end dates changed [2, 5].

A year of storms, one template

The 2026 orders read like a weather log. Winter Storm Fern in January covered about 25,000 devices, by Federated’s estimate [2]. Winter Storm Gianna a week later covered about 35,000 [3]. Tropical Storm Bertha in July covered about 60,000 [4]. By late September the orders were for Hawaii, where Tropical Storm Nolo covered about 500 devices [5]. The paragraph describing customer harm in the Fern, Gianna and Bertha orders is the same paragraph with a different number dropped in [2, 3, 4].

The rest of the federal storm machinery was running too. Florida’s governor declared a state of emergency in 25 Panhandle and North Florida counties on October 6, the day the system became Tropical Depression Nine [8]. The FCC’s public safety bureau activated its Disaster Information Reporting System on October 8 at the request of Alabama, Florida and Mississippi, and expanded it to Geneva County, Alabama, two days later [6]. Providers in that system report daily on equipment status, restoration and whether they’re running on commercial or backup power [6].

What it means if you build things

This section is opinion.

Fail-closed is the right default, and it has a cost the rules push onto paperwork. If the sensor can’t hear, assume the federal system is there. I’d write it that way too. Protecting federal systems is the whole bargain that opened this band. But the failure that keeps triggering the rule isn’t a federal user showing up. It’s a sensor site losing power. The FCC’s answer, storm after storm, is a delegated waiver with the same five conditions. That works. It also means the fallback for a known, recurring failure mode lives in a filing someone has to draft while the storm is still offshore.

Lead time is the thing I’d worry about. Federated filed on October 7 and the grant came October 9, the day Isaias was forecast to make landfall [1, 7]. Two days is fast for an agency. It’s also not a guarantee. The rules give no automatic outage mode. Relief depends on the SAS operator asking and the Bureau answering in time.

If you run a private network on CBRS, put this in your outage model. Federated’s own description of who’s on these networks runs from homes to schools to oil and gas companies [1]. Your devices can go quiet because a sensor somewhere else lost power, even if your own site is fine. I’d ask your SAS provider three things: which DPAs your CBSDs sit in, whether it has asked for these waivers before, and what your devices do when a zone activates. The fifth condition matters here too. Your service can still be pulled mid-waiver if NTIA or the Department of War asks [1].

The federal side gets less in the record than the commercial side. The orders carry Federated’s estimate of affected devices and customers [1, 2, 4]. They don’t say whether a federal system ever needed protection during a waiver window, or whether condition 5 has ever been used. I’m not suggesting anything went wrong. I’m saying a rule that gets waived this often deserves a record of how the waivers turned out.

One small drafting note. The order calls the storm “Tropical Storm Isaias” in its opening paragraph, while the Hurricane Center’s 4 p.m. advisory that day said “Isaias is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale” [1, 7]. Copying a template forward will do that.

What I’m watching

• October 23. That’s when the waiver runs out, unless restored power ends it sooner or Federated asks for an extension [1]. An extension request would have to show its reactivation steps, which would be the first public account of what happened to these sensors in this storm.
• The restoration confirmation. Federated owes regulators and the military notice within three business days of getting power and backhaul back [1]. Whether that shows up in the docket will tell you how much of this process happens in public.
• DIRS. Daily outage reports are due at 10 a.m. Eastern until the FCC deactivates the system [6]. The aggregate numbers will show how much of the Gulf Coast’s network ran on backup power, which is the same dependency the CBRS sensors have.