47 CFR § 88.109 - Time division duplex requirement.

---
identifier: "/us/cfr/t47/s88.109"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "47 CFR § 88.109 - Time division duplex requirement."
title_number: 47
title_name: "Telecommunication"
section_number: "88.109"
section_name: "Time division duplex requirement."
chapter_name: "FEDERAL COMMUNICATIONS COMMISSION"
subchapter_number: "D"
subchapter_name: "SAFETY AND SPECIAL RADIO SERVICES"
part_number: "88"
part_name: "UNCREWED AIRCRAFT SYSTEM SERVICES"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "47 U.S.C. 154(i), 303, 307."
regulatory_source: "90 FR 1395, Jan. 8, 2025, unless otherwise noted."
cfr_part: "88"
---


# 88.109 Time division duplex requirement.

Transmitters operating in the 5030-5091 MHz band must comply with the time division duplex (TDD) frame structure and timing accuracy requirements specified in technical standard RTCA DO-362A (incorporated by reference, see § 88.117) sections 2.2.1.3 and 2.2.1.3.1.