AT&T has filed a lawsuit against T-Mobile alleging harmful interference linked to T-Mobile’s operation of 5G systems in the 2.5 GHz band, according to reporting by RCR Wireless. The case spotlights long-running tensions in the wireless industry over spectrum access, interference risks, and the responsibilities carriers have when deploying new technologies on shared airwaves. While litigation between major telecom providers is not new, this dispute arrives at a time when 5G competition is intensifying and regulatory scrutiny around mid-band spectrum is growing.
RCR Wireless reports that AT&T’s complaint centers on claims that T-Mobile’s 2.5 GHz operations create interference affecting AT&T’s customers and network performance. AT&T alleges that the problem occurs when T-Mobile uses high-power transmissions without, in AT&T’s view, sufficient safeguards to prevent overlap or degradation of neighboring spectrum use. The lawsuit requests injunctive relief, potentially requiring T-Mobile to modify its deployment practices.
(Source: RCR Wireless, “AT&T sues T-Mobile US,” Dec. 2025.)
Understanding the Spectrum at Issue
The 2.5 GHz band has become a critical piece of mid-band 5G strategy in the U.S. T-Mobile acquired extensive 2.5 GHz licenses through its merger with Sprint in 2020, giving it a substantial competitive advantage. Mid-band spectrum offers an effective balance between coverage and capacity, making it extremely valuable for delivering fast, wide-area 5G.
Because carriers operate multiple technologies across adjacent bands, coexistence rules are essential. These rules are overseen primarily by the Federal Communications Commission (FCC), which establishes technical standards intended to prevent harmful interference. However, even with regulatory frameworks in place, real-world deployment conditions may vary by market, terrain, and device mix, creating room for disputes like this one.
AT&T’s Allegations and Requested Relief
According to the reporting, AT&T claims that T-Mobile’s equipment or configurations exceed power limits or otherwise cause signal bleed that disrupts AT&T’s network. AT&T asserts that its customers experience degraded connectivity as a result. The lawsuit asks the court for:
- An injunction requiring T-Mobile to adjust or limit its use of 2.5 GHz systems
- Possible compensation for damages associated with interference
- Enforcement that ensures compliance with FCC technical standards
While the FCC governs spectrum policy, carriers may bring disputes directly into federal court, especially when they believe another provider is violating rules or harming commercial operations.
T-Mobile’s Position
T-Mobile has not yet issued detailed public statements in response to the filing, but historically the company has argued that its 2.5 GHz deployment fully complies with FCC regulations and represents one of the most efficient 5G upgrades in the U.S. It is likely that T-Mobile will claim the network operates within permitted parameters and that AT&T’s allegations are either exaggerated or mischaracterize technical behavior that falls within normal tolerances.
The outcome may hinge on technical measurements, engineering data, and expert testimony about whether harmful interference actually occurred and whether T-Mobile’s equipment exceeded regulatory thresholds.
A Broader Industry Trend
This lawsuit reflects broader competitive dynamics across the wireless sector:
- Race for 5G leadership — Mid-band spectrum is limited and extremely valuable; disputes over its use are increasing.
- Regulatory complexity — Even well-defined FCC rules can be interpreted differently by carriers deploying networks at national scale.
- Heightened scrutiny — As carriers expand into advanced 5G and edge-computing services, tensions around performance, coverage claims, and customer experience continue to intensify.
Legal action between carriers has historically shaped technical standards, including tower siting, roaming agreements, and device compatibility. This case may similarly influence future coexistence requirements for mid-band spectrum.
Why This Matters for the Telecom Ecosystem
Even though the lawsuit is focused on two major carriers, interference disputes affect the entire wireless environment. Network performance issues can impact consumers, enterprises relying on mobile connectivity, and broader adoption of 5G applications such as IoT, logistics automation, and emergency services.
If courts or regulators impose new conditions on how spectrum is used, carriers nationwide may need to adjust deployment strategies. The case could also influence future spectrum auctions, investment decisions, and cross-carrier competitive claims.
An Ongoing Story
The litigation is still in its early stages, and both technical and legal questions remain unresolved. As filings progress, the case will likely shed new light on how carriers interpret FCC rules and how aggressively they are willing to defend their competitive positions in the 5G era.
For now, the lawsuit underscores a fundamental truth in wireless communications: as networks evolve, so do the disputes over the airwaves that power them.
Source: RCR Wireless, “AT&T sues T-Mobile US,” Dec. 4, 2025.
