MediaFLO was a technology developed by Qualcomm for transmitting audio, video, and data to portable devices such as mobile phones and personal televisions, used for mobile television. In the United States, the service powered by this technology was branded as FLO TV.
Broadcast data transmitted via MediaFLO includes live, real-time audio and video streams, as well as scheduled video and audio clips and shows. The technology could also carry Internet Protocol datacast application data, such as stock market quotes, sports scores, and weather reports. Qualcomm press release on "Live Datacasting", 05Apr2006
In October 2010, Qualcomm announced it was suspending new sales of the service to consumers. In December 2010, AT&T announced that it will purchase Qualcomm's FCC licenses in the 700 MHz band. FLO TV discontinued service on March 27, 2011.
The "FLO" in MediaFLO stood for Forward Link Only, meaning that the data transmission path is one way, from the tower to the device. The MediaFLO system transmitted data on a frequency separate from the frequencies used by current mobile telephone networks. In the United States, the MediaFLO system used frequency spectrum 716-722 MHz, which had previously been allocated to UHF TV channel 55.01Nov2004 Qualcomm press release regarding 700 MHz spectrum usage for MediaFLO
FLO was standardized within ETSI as TS 102 589, and has components standardized within the Telecommunications Industry Association (TIA 1099, 1102, 1103, 1104, 1120, 1130, 1132, 1146 and 1178.)
MediaFLO was a competitor to the Korean T-DMB, the Japanese 1seg, and the European DVB-H standards.
Qualcomm conducted MediaFLO technical trials internationally, with the intention of forming partnerships with existing multi-channel content providers and service operators, but has since discontinued development.
The protocol was developed because of the inherent spectral inefficiency of unicasting high-rate full-motion video to multiple subscribers. Additionally, traditional analog television and over-the-air terrestrial digital television signals (DVB-T) were difficult to implement on mobile devices, due mostly to issues of power consumption. ATSC, used only by the United States and its neighbors, also has difficulty even with fixed reception due to multipath, and mobile ATSC-M/H (which is free-to-air from individual TV stations) was not finalized until 2008.
In addition, the transmission need not convey as high a resolution as would be needed for a larger display. MediaFLO streams are only 200-250 kbit/s, which would be insufficient for larger screen sizes.
In the now-defunct United States implementation, FLO was transmitted by a network of high-power broadcast transmitters operating at effective radiated powers as high as 50 kilowatts. This allowed for a coverage area of a transmitter to be as large as 30 to 40 kilometers (19 to 25 mi). The activation of many of these transmitters was delayed due to the official end of analog TV broadcasting on channel 55 being delayed. Immediately following the transition, the FLO network was expanded to several new markets, and coverage was enhanced in some existing ones.
The transmission was an encrypted OFDM set of QAM signals sent on a 5.55 MHz channel from 716-722 MHz (former UHF TV channel 55). The band was auctioned off by the Federal Communications Commission (FCC) and known as the "Lower 700 MHz Block D". Qualcomm also bought, in a later auction, the use of former analog UHF TV channel 56 (722-728 MHz) in Boston, Los Angeles, New York, Philadelphia, and San Francisco for additional services. However, this is owned by Manifest Wireless (a subsidiary of Dish Network's Frontier Wireless) in most other media markets, where ATSC-M/H signals were on air. All of the transmitters sent the same signal and used the same frequency, forming a single-frequency network. This allowed the mobile to decode the signal from more than one transmitter in the same way that it might if it was a multipath-delayed version from the same transmitter. All stations used callsign WPZA237, but each has an identifier indicating its group and number. For example, one station in the metro Atlanta media market was ATL-006, while another was ATL-014.