At a time of increasing demand for video on mobile devices, it is vital to use the resources on existing mobile networks as efficiently as possible. 4G Broadcast (LTE eMBMS) offers the possibility of addressing issues of congestion and peak demand for popular content by sending a single stream once for reception by multiple users within a cell. This capability could be enabled in localised areas of peak demand, within existing 4G networks, and switched on as required, to allow the network to be dynamically optimised for the current traffic conditions. BBC Research & Development has been investigating how 4G Broadcast technology might be used to improve the delivery of streamed content to mobile devices. We have demonstrated two example use cases - firstly as part of an app tailored to a specific event (for example at a sports venue), and secondly by connecting the technology seamlessly to BBC iPlayer (the BBC's Internet streaming service that offers both live and catch-up content) to allow viewers to continue watching popular content in congested areas, without the experience being spoilt by buffering. This paper will explain the work BBC Research & Development has been carrying out on 4G Broadcast and present the results of recent trial work.