Two-phase rollout is intended to improve game flow, enhance officiating accuracy
Beginning with games on Nov. 1, NBA referees are using headsets to communicate in real time with one another and the NBA Replay Center. The rollout is the first in a planned two-phased approach to deploy the new communication system to improve game flow and enhance officiating accuracy.
In the first phase, each referee will have an earpiece clipped on their uniform. The referees will unclip the earpiece and place it in their ears only during instant-replay review and as needed during other stoppages but not during live play.
Pending evaluation of the first phase, the second phase will begin in January with earpieces worn throughout the game, including during live play. In the second phase, referees will be able to communicate directly with the Replay Center and each other at all times during the game. The second phase will run through at least the NBA All-Star break in February.
Prior to being implemented, the technology was tested extensively during NBA preseason games (in 2024 and 2025), NBA Summer League (2023-25), and the NBA G League Winter Showcase (2022-24).
The NBA says it will work closely with the National Basketball Referees Association throughout the process.
Infrastructure and Components
The new referee-comms system is based on the Riedel Bolero S. Configured in standalone mode, an NSA-002A network stream adaptor handles bidirectional conversion between analog and AES67 signals, enabling connection to the legacy RTS RVON system in the replay center and to the venue PA system and the broadcaster’s audio system.
Each NBA arena is also fitted with three comms antennas: one on each stanchion or hoop support, one in the locker room, and an NSA-002A to connect to the RVON that goes back to the Replay Center, the PA-announce system, and the broadcast truck. Each arena also has a Bolero S beltpack for each referee and a full-size Bolero for a technician.
A total of 172 headsets, custom-fabricated by Riedel and similar to the ones it supplies to the MLB, are equipped with dual-PTT buttons.
The rollout also involves upgrades to the NBA Replay Center: enhanced referee communications, native use of high-frame-rate video, and, for broadcasts and fans, increased transparency on how each call is made. In addition, the NBA has expanded SMPTE ST 2110 workflows across its arenas; its Secaucus, NJ, broadcast facility; and remote data centers connected via the league’s HSAN network, delivering greater resiliency and scalability for media services through a fully distributed architecture.
Future reconfiguration and expansion of the system is under consideration.
