Wireless, Uncompressed HD

Loea Corp. transmitters look down upon Qualcomm Stadium prior to theSuper Bowl. They later sent uncompressed, wireless HD signals of beautyshots to ABC’s broadcast truck.

January's Super Bowl telecast on ABC featured an interestingtechnical development in high-definition broadcasting — anuncompressed, point-to-point, wireless transmission in realtime of afull 720p HD signal for instant broadcast during the network's high-defversion of the game. The shots were part of an experiment conductedduring the game to air wide beauty shots of San Diego's QualcommStadium. This became necessary, as it turned out, for both ABC's HD andstandard-def telecasts because security concerns prohibited thetraditional use of a blimp for overhead venue shots.

According to Mike Strein, ABC's general manager of technology andstrategic planning, shots manufactured by the experiment aired 10 to 15times during the Super Bowl broadcast, in realtime on both the HD andSD telecasts (downconverted for the SD show). Strein says ABC managedthe feat by using a “virtual fiber” transmission technologycreated by Hawaii's Loea Corporation, in combination with a special,high-frequency spectrum granted to the telecast on a temporary basis bythe FCC.

“We placed an HD camera [a Panasonic AJ-HDC27 VariCam] andoperator on a hillside location overlooking the stadium, about ahalf-mile away,” explains Strein. “We connected the cameraby simple coax cable to a pair of transmitters [two for redundancy]provided by Loea that allowed us to transmit a pencil-beam signal above70GHz, point-to-point, to our HD production truck outside the stadium.This was a totally uncompressed signal transmitted via radio waves, andit worked perfectly. Our HD people were able to air the shotsinstantly, and our standard-def people were able to downconvert thesignal and air it several times.”

Strein says this was an important success, because it convinced himit is possible to air a realtime, uncompressed HD signal in situationswhere fiber is not practical, and where delays caused by the use ofcompressed microwave signals are not acceptable.

“We tried using free-space optics and microwave transmissionsat the 2000 Super Bowl in Atlanta, and it just didn't work well for alive telecast,” says Strein. “In this case, the transmitterlinks are simple to set up — they took just minutes. Theproduction trucks had no problem picking them up because we werebroadcasting within line-of-sight.”

Lou Slaughter, Loea's CEO, says the virtual fiber technology evolvedfrom work done by the company's parent, Trex Enterprises. Trek wasworking to develop passive millimeter-wave cameras for the Departmentof Defense — cameras capable of receiving signals within the70GHz to 90GHz spectrum. Loea's communications link at this year'sSuper Bowl, built from that technology base, communicated at 1.485Gbps,which is equivalent to 1,000 T1 lines, according to Loea officials.

“This frequency is not yet commercially available to thepublic, but we applied to the FCC for a temporary license to prove theconcept at the Super Bowl, and the FCC is now in the process ofdeveloping rules to make this frequency spectrum permanently availableto the private sector,” says Slaughter. “If they moveforward on this, as we expect, the potential applications for livesporting events and other types of shows broadcasting in HD aresignificant because it does away with the issues of cables orcompressed signals. The rules being considered by the FCC would permitanyone to use the frequency, and Loea would be able to offer thisproduct to the industry based on our hardware designs that allow us tocreate and transmit HD pencil beams from a very simplesetup.”

Strein thinks the technology has great potential for HDbroadcasters.

“We definitely have an interest in using it again,” hesays. “The weakness, of course, is that it has to transmitline-of-sight, but I know they are developing it to work with multiplelinks to get that kind of bandwidth around corners. That might end upbeing more complicated than what we did, but on the other hand, itwouldn't be more complicated than trying to put down miles offiber.”