This dataset identifies 36 patent families published between 2015 and 2026 that combine positive train control or train control system terminology with wireless-specific claim language such as 220 MHz radio, train-to-wayside communication or secure wireless messaging. That is a small, narrowly defined corpus, not the full universe of rail signalling patents. Broadening the search terms or IPC codes would surface additional adjacent filings in general railway control or wireless networking.

Based on this dataset, no: filings peaked at 8 in 2017 and had fallen to zero by the 2022 midpoint, with no tracked assignee showing filings in the most recent year. Publication lag of roughly 18 months means the very latest year is always undercounted, but the multi-year plateau before that lag window is a genuine signal rather than a reporting artefact. A team evaluating freedom to operate should treat the core apparatus claims as largely settled rather than still being contested.

US10501102B2, assigned to Avante International Technology and granted in December 2019, claims a positive train control system using RFID devices embedded in the track way to store location data, read by an RFID reader mounted on the train. The location data is processed on-train or at a central facility to check whether the train's position and timing match its routing order, with alerts generated when they do not. Anyone building an RFID-based track-location approach to PTC should review its claim scope directly rather than relying on the abstract alone.

The assignee base in this corpus is thin and includes both corporate filers and named individual inventors who appear together across several filings, alongside at least one university. No single assignee shows recent-year filing momentum, and citation weight in the corpus sits with early apparatus and RFID-based PTC filings rather than with any one dominant current player. That pattern is more consistent with a niche, technically mature field than with an actively contested market.

The corpus is heavily concentrated in the core B61L railway traffic control subclass, with only single-digit spillover into brakes, vehicle bodies, couplings, digital data processing and educational aids. Sub-areas such as 220 MHz radio link redundancy, secure wireless authority messaging and multi-train cooperative control links appear thinly claimed relative to the core PTC apparatus filings. Those branches are worth a closer prior-art check before assuming they are clear, since thin coverage in a search corpus is a starting signal, not a guarantee of open claim space.