cts were introduced9 but failed to gain mass-market traction. A DRM receiver works well under a wide range of operating conditions and is power efficient. It is, however, bandwidth limited and (at present levels of compression) incompatible with any existing TV content standards. There is a wide range of global programming available, Vatican Radio being one example. Up-to-date information on DRM receivers and DRM programming can be found on the Digital Radio Mondiale web site. 15.6 DAB, DMB and DVB H DAB/DMB is potentially useable across three radio bands - the VHF FM band, band 3 at 220 MHz and L band at 1.5 GHZ. It is MPEG2 TS and MPEG4 Part 10 compliant and supports useful features like multimedia object transfer, SO it's definitely not now just an audio delivery system. At 2011 there are only 15 countries with DAB networks deployed, which is not enough to achieve global mass market adoption. 11 It does work well in the UK and despite the limited global uptake there are nice receiver products available. 12 DVB-H has proved more problematic. The intention was that cellular phones would have mobile TV delivered via a DVB H physical layer either at Band 3 VHF, Band 4 or Band 5 UHF. Crown Castle purchased a 5-MHz bandwidth allocation in the US between 1670 and 1675 MHz and in 2005 started a DVB H trial in Pittsburgh. Technically, DVB H was quite attractive. DVB-H increased the power efficiency of the receiver by time slicing. If multiplexed with a DVB T signal for example, a 2-Mbit burst would be taken out of the DVB T 15-Mbps stream and sent in a 146-millisecond burst. The receiver then powered down for just over 6 seconds then powered up for the next burst. The 2-Mbit burst was read into and out of a buffer at a constant 350 kbps. 8 http://www.radioandtelly.co.uk/visualradio.html. For example, a product from Coding Technologies subsequently acquired by the Dolby Corporation w.dolby.com/professional/technology/broadcast/he-aac-dolby-metadata.html 10 http://www.drm.org/products. 11 tp://www.worlddab.org/country_in