Multimedia Matters: Religion And Cognition
By Peter J. Brown
Spreading the news that the Church of Sweden has inked a deal with Satlynx SA to equip all of its 3,500 churches throughout Sweden with satellite dishes is about as close to religion as this column is ever going to venture. But when it comes to cognition, the process of acquiring knowledge, our quest never ends.
We wandered into the cognitive space via software defined radio (SDR) and heard the news that Congress might be slashing more than $230 million from the Joint Tactical Radio System (JTRS), which is where much work has been underway on SDR. We encourage readers to keep abreast of SDR-related developments, while realizing that it is not the same thing as cognitive radio (CR). We asked Charles Bostian, director of Virginia Tech’s Center for Wireless Telecommunications to help us sort out the not so subtle differences between SDR and CR. The center is extending its research in the field of CR to advance cognitive network capability under a three-year National Science Foundation grant.
"SDR uses software and digital electronics to generate waveforms and perform the key functions of a transmitter and receiver," says Bostian. "A piano generates music via analog hardware, keys, hammers, strings and a sounding board. You can modify the sound a little bit by using the pedals, but piano music still comes out. The piano is like a hardware radio. A keyboard generates music using digital electronics and software. It can sound like almost anything, depending on the software you load. Load trumpet software and it will sound like a trumpet. The keyboard is like an SDR."
When SDR and CR converge, big things happen. CR is aware of its environment, its own capabilities, the U.S. Federal Communications Commission rules, and its user’s needs, says Bostian.
"CR can configure itself autonomously and intelligently to meet the user’s needs and it can learn from past experience. You can think of a cognitive radio as consisting of a radio platform plus a cognitive engine that serves as a brain to operate the radio," says Bostian. "SDRs make the best radio platforms because everything about them can be changed by changing the software; thus they are easy for the cognitive engine to control. A legacy hardware radio can be made cognitive to the extent that it has outputs and inputs that a cognitive engine can understand and control."
And what exactly is the satellite angle here? Do CR applications in the satellite environment face any unique challenges?
"It depends on the application. CRs do things like find an open frequency that can legally be used and establish a link. Things that would make this hard on a satellite path would be the time delay associated with the path length, the limited ability of a terrestrial receiver to sense the RF environment at other downlink sites, and the limited fade margin of most downlinks," says Bostian.
Bostian’s input here is more than casual background info, it is a reminder that the next generation of hybrid CR/SDR solutions are likely to emerge in an IP-saturated wireless world awash in terrestrial and even meshed transmitters of every size and description. Like Internet protocol (IP) TV and the satellite sector today, there will be opportunities for some, and big headaches for others.
A continent away, Nolo Letele, CEO of direct-to-home service provider Multichoice Africa, appears to be cognitively in tune with what his customers want.
"Multichoice will continue to offer a 60-channel bouquet, as well as a smaller 11-channel tier. There are no plans to add new channels in the short term," Letele says, adding that Multichoice would be launching its digital video recorder in November with video-on-demand to follow next year, and high-definition TV in 2007.
Multichoice has swapped out its legacy decoders and is conducting joint IPTV trials. Interactive services now include interactive TV advertising along with conversion of all sports data to enhanced mode on seven dedicated sports channels.
As for cognitive meltdowns during the rainiest October in memory in the Northeastern United States, a new satellite broadband customer who found himself signal free in severe weather reports that when he attempted to contact a customer call center, nobody volunteered any information about the phenomenon of rain fade. Only after being prodded did a call center contact finally come clean. The solution, this customer was told, was to do a manual reset, that is, shut it down for two minutes.
"I did it three times today," the customer said. "Why not incorporate an automatic reset into the unit?"
Lastly, I want to end 2005 by taking this opportunity to thank everyone who helped all the planes fly, trucks roll, ships sail and satellite dishes lock on during the enormously complex and massive relief efforts that unfolded after Hurricanes Katrina and Rita in the Gulf Coast region of the United States as well as in the aftermath of the earthquake in Asia.
Satellite technology made a big difference and rest assured that it will make more of a difference in our responses to future disasters. And it was lots of folks wearing various hats — DBS, VSAT, FSS, MSS and DARS — who worked hard for long hours, day after day, both in the field and behind the scenes, to help links light up and get the right equipment to the right place in a timely manner.
So give thanks if you have a roof over your head this holiday season, give a little to the relief effort if you can and be thankful always if a satellite link is close at hand.
Peter Brown is Via Satellite’s senior Multimedia & Homeland Security editor.