The Indianapolis Motor Speedway Radio Network (known typically as the IMS Radio Network or the INDYCAR Radio Network), is an in-house radio syndication arrangement which broadcasts the Indianapolis 500, the NTT IndyCar Series, and Indy Lights to radio stations covering most of North America. The network, owned by the Indianapolis Motor Speedway and headquartered in Speedway, Indiana, claims to be one of the largest of its kind in the world. It currently boasts over 350 terrestrial radio affiliates, plus shortwave transmissions through American Forces Network and World Harvest Radio. The network is carried on satellite radio through SiriusXM, and is also accessible through online streaming, and downloadable podcasts. For 2017, the broadcast reached 20.5 million listeners.