What is that box on the pole outside your house?
If the box is on a streetlight or utility pole, it is probably a small cell. Under FCC rules that means a radio site on a structure about 50 feet tall or less, with no antenna bigger than three cubic feet. The US had 447,605 cell sites at the end of 2024, and 166,264 of them were small cells, according to the wireless industry's annual survey. Your city or county still approves where they go, but federal law limits what it may weigh. Published field surveys near these sites report radio-frequency levels at a tiny fraction of the exposure limit.
This site explains the poles and towers near you using the documents behind them: FCC rules and orders, auction records, court opinions and published field measurements. We cite the document behind every number.
Small cell or macro tower
The FCC's 2018 Small Cell Order drew the contrast in plain terms. The 3G and 4G era was built on "large, 200-foot towers," while new deployments use antennas "often no larger than a small backpack." The order also cited estimates that upwards of 80 percent of new deployments would be small cells.
What makes something a "small wireless facility" in law is a set of size tests in 47 CFR 1.6002. A site has to meet all of them:
| Test | Limit in the FCC rule |
|---|---|
| Height of the structure | 50 feet or less including antennas, or no more than 10% taller than nearby structures |
| Raising an existing structure | Not above 50 feet, or by more than 10%, whichever is greater |
| Each antenna | No more than 3 cubic feet |
| All other equipment on the structure | No more than 28 cubic feet in total |
| RF exposure | Must not exceed the FCC's safety limits |
Anything larger is reviewed as an ordinary wireless facility, on the FCC's longer clocks.
How many cell sites the US has
CTIA, the wireless trade group, has surveyed carriers since 1985. Its count of cell sites grew about three and a half times between 2001 and 2024.
Counts include small cells. The survey is voluntary; CTIA says the 2024 round covered carriers serving more than 98% of connections.
Show the numbers
| Year | Cell sites |
|---|---|
| 2001 | 127,540 |
| 2002 | 139,338 |
| 2003 | 162,986 |
| 2004 | 175,725 |
| 2005 | 183,689 |
| 2006 | 195,613 |
| 2007 | 213,299 |
| 2008 | 242,130 |
| 2009 | 247,081 |
| 2010 | 253,086 |
| 2011 | 283,385 |
| 2012 | 301,779 |
| 2013 | 304,360 |
| 2014 | 298,055 |
| 2015 | 307,626 |
| 2016 | 308,334 |
| 2017 | 323,448 |
| 2018 | 349,344 |
| 2019 | 395,562 |
| 2020 | 417,215 |
| 2021 | 418,887 |
| 2022 | 414,571 |
| 2023 | 432,469 |
| 2024 | 447,605 |
The newest release, CTIA's 2026 survey highlights, gives a rounded 442,000 sites for 2025 and about 173,000 small cells, which it calls "nearly 40%" of all sites. That rounded total sits below the 2024 count, and the highlights do not say why, so treat the 2025 figure as provisional until CTIA publishes its full table. Small cells, by CTIA's own chart, have grown from 79,000 in 2018.
Who approves the antenna on your block
Section 332(c)(7) of the Communications Act, at 47 U.S.C. 332, leaves siting decisions with state and local governments, then fences them in. A city may not unreasonably discriminate among carriers, may not effectively prohibit service, must act within a reasonable time, and must put any denial in writing backed by substantial evidence. It also may not regulate a facility "on the basis of the environmental effects of radio frequency emissions" if the facility meets FCC rules.
FCC rules then set the clocks: 60 days to review a small cell on an existing pole, 90 days for one on a new pole, with longer periods for bigger sites. Upgrades to existing towers that do not substantially change their size must be approved. The details, the fee caps and what a 2020 appeals court threw out are in our guide to what local rules can and cannot do.
What measured RF levels look like
The FCC's general-population limit is 1.0 milliwatt per square centimeter for frequencies from 1.5 to 100 GHz. That range covers every band in our 5G auction table except 600 MHz. Field surveys near cell sites report results as a percentage of a limit like that one.
- 0.14%
- highest total reading at 50 Melbourne locations, ARPANSA, March to April 2022
- 5% or less
- worst-case estimate at 56 UK 5G macro sites, UKHSA, 2025
- 0.0082%
- highest millimeter-wave reading near US small base stations, 2025 study
- 1.0 mW/cm²
- FCC public limit from 1.5 to 100 GHz
Source: Henderson, Bhatt and Loughran 2023; Calderon et al. 2025; Bushberg and Butcher 2025; 47 CFR 1.1310.
The FCC's own engineering bulletin says ground-level power densities near cellular antennas mounted higher than 10 meters are "typically hundreds to thousands of times below" its limits (OET Bulletin 65). The FCC enforcement case we found was right in front of the antennas: in 2015 FCC agents measured about 175% to 300% of the public limit twelve inches from rooftop panels in Phoenix, where barriers were broken and signs were unclear. Our page on RF measured near 5G sites puts the studies side by side and says which limit each one used.
What people do after reading the numbers
Some readers stop at the survey data. Others ask the city for the carrier's RF compliance paperwork, speak at a siting hearing, or buy a meter. Some buy products such as EMF stickers for phones and routers. This site sticks to what the documents show about the sites themselves.
If you want to know what the 5G bands from 600 MHz to 47 GHz are and what the FCC charged for them, start with 5G frequency bands explained. The short version: the C-band auction alone drew $81.2 billion in gross bids, and the public exposure limit at those frequencies is the same 1.0 mW/cm² as at 28 GHz.
Small Cell Street explains what is mounted on the poles and towers near you, who gets to approve it, and what measured radio-frequency levels look like, using FCC records, statutes and published survey data. It is not affiliated with any carrier, tower company or city.