Last week, ANATEL issued Official Letter 81/2025, clarifying the definition of indoor environments for the 5150-5350 MHz frequency band in vehicular applications, per items 3.1.48 and 11.2 of Act 14448 (Click here to access Act 14448).
Key Updates:
- Indoor Environment Definition: ANATEL defines an indoor environment as one that attenuates transmitted signals due to building penetration, reducing emissions in multiple directions (item 3.1.1 of Act 14448).
- Vehicle Restrictions: The 5150-5350 MHz band (WLAN B1/B2) is permitted only in fully enclosed vehicles, such as cars and trucks.
- Prohibited Vehicles: This band cannot be used in open vehicles, including motorcycles, tuk-tuks, and convertibles.
Official Letter Excerpt:
ANATEL acknowledges receipt of Letter OFFICIAL_SEI_COMMITTEE OCDS_057_25, requesting guidance on applying items 3.1.48 and 11.2 of Act 14448/2017 to motorcycles, tuk-tuks, and convertible cars. Given the definition of a “closed environment (indoor),” ANATEL confirms that these vehicles do not meet indoor criteria, as they lack physical barriers to degrade signal emissions.
For more details, click here to access the official letter.
