Year in Review, 2012

Another year comes to a close, and it was a busy one!  Here is a quick summery what we’ve been up to with our satellite trucks, flyaways, and teleport

January:  Iowa Caucus.  What better way to kick off the political season than a trip to freezing
Des Moines in the winter? 

January:  Ron Paul visits DCI Studio.  DCI recently installed an insert studio for live interviews via satellite or fiber, and Ron Paul stopped by to talk with Current TV.

 Ron Paul with DCI founder Al Levin

February:  New Hampshire Primary.  After Iowa comes equally cold New Hampshire, and all the satellite trucks rush from Des Moines to Manchester to cover the next early primary state.

February:  Pope Benedict in Cuba.  Pope Benedict made the first papal visit to Cuba in over 20 years, and for the first time ever, DCI provided TWO flyaway uplink systems on the same job.  We had one dish based at the Santiago broadcast center, and our ultra portable flyaway uplink dish traveled (11 hours in a van, overnight!)  between the two mass sites, one in Santiago and the other in Havana.

April:  Corporate Event in Cancun.  A few days in Cancun was a nice break in the political news cycle.  DCI’s flyaway provided video backhaul for the Budlight Bucket Challenge, which was broadcast live on the Budweiser website and Facebook pages.  We used our ultra portable flyaway satellite uplink configured for airline checked baggage, delivering a redundant HD H.264 transmission solution in under 500lbs across 9 cases. 

May:  787 Dreamliner:  Three of the DCI staff are pilots, and we were excited to cover the 787 DreamTour stop in DCA National Airport.  Treated to a private media walk through, we got to talk to Boeing’s chief pilot and see the entire aircraft from cabin to the cockpit’s Heads Up Display.  We used our microwave transmitter with a high gain antenna to send live video to the Clocktower, for a business network live shot- without a satellite truck. 

May:  John Edwards trial, Greensboro NC.  The much covered trial of former Presidential candidate John Edwards ended with a mistrial.  DCI provided a HD satellite uplink truck for NBC News. 

June:  G20 meeting in Los Cabos, Mexico.  The G20 held their annual meeting at the tip of Baja California Sur, in Cabo San Lucas.  A DCI flyaway uplink provided multiple paths of video back to the US.

September:  Joe Biden’s Debate Response The Obama campaign hired DCI to provide a satellite truck at the Vice President’s residence at the Naval Observatory in northwest Washington.  Joe Biden delivered a response to the first presidential debate that was carried live on YouTube and the campaign website.  DCI’s compact satellite uplink truck worked well in the small parking area in front of Biden’s house.

November:  Hurricane Sandy.   Both DCI satellite trucks were busy covering Hurricane Sandy and the subsequent damage.  During the storm we were positioned in Ocean City, MD and Long Island, NY.  After the storm, the Ocean City satellite truck went to Long Beach Island, NJ and the NY truck covered damaged areas in coastal New York.

November:  Election Night Boston.  DCI deployed to Boston to cover the highly anticipated 2012 presidential election.  Setup in a position outside the convention center, we got the witness the many Romney supporters going in, and the always entertaining Vermin Supreme delivering speeches on the outside. 

DCI also expanded our multicamera production capabilities in 2012 with a new ATEM switcher and 18′ jib, more info on these additions will be coming soon!  Contact us for all your satellite uplink truck, flyaway uplink, teleport, and video production needs in 2013! 

Progression of Modulation

When satellites first became commercially available for television broadcasts, analog transmission was the standard way video was sent.  Analog uplinks require large bandwidth- typically no less than 18MHz but often a full 36MHz transponder was used.  Large bandwidth requires large antennas and power, meaning a small portable uplink was limited to only one, or sometimes two paths, or channels on the uplink.

In the late 1990s, DVB-S, or Digital Video Broadcasting for Satellite- became more common.  A DVB-S uplink is made up of two main parts- the encoding and modulation.  Encoding is the process of converting the analog or uncompressed digital video- known as baseband- into a compressed format more easily sent over the limited bandwidth of a satellite uplink.  Modulation takes these digital bits and sends them over a radio frequency.  The most simple form of digital modulation is Morse code, turning a signal on and off to spell out letters.  Modulation used for DVB is far more advanced, and always improving, finding better ways to transmit more data in less bandwidth.  A typical uplink in 1998 used QPSK- which stands for Quadrature Phase Shift Keying, where each “symbol” of the uplink signal can represent 4 states for two bits per symbol by adjusting the phase of the RF carrier.  DVB includes FEC, or Forward Error Correction, which allows a receiver to produce a error-free output despite noise or other interference.  The FEC is expressed as a ratio, from 1/2 to 9/10 being common ratios.  1/2 means 1 out of every 2 bits is a data bit, and 9/10 is 9 out of 10 are data bits, the rest is the error correction overhead.  A signal uplinked with 1/2 can be received at much lower levels than 9/10, but the trade off is there is much less usable data available in the channel. 

QPSK modulation constellation

DVB also includes several QAM modes, which changes the amplitude of a signal.  Uplinks that use QAM modulation can carry more information in the same bandwidth.  There is no free lunch, and the tradeoff of putting more data in less bandwidth is the signal gets harder to receive, and requires larger antennas to “pick up” more of the signal.  Just as its harder for your eye to differentiate between 16 shades of a color compared to 4 shades, the same holds true for satellite links.  It gets even worse with even higher levels that have more “shades”, such as 64QAM. 

16-QAM modulation constellation

64 QAM modulation constellation.  More “states” per symbol makes it harder to “see” what is being sent. 

Published in 2003, the second generation improvement to the DVB standard, known as S2, was created.  DVB-S2 has many improvements over the older DVB-S (now sometimes known as S1).  More efficient error correction allows more data at lower signal levels, more FEC ratios to choose the most optimal error correction level, and more modulation constellations to pick from. 
8PSK modulation is very common in DVB-S2 uplinks, and allows about 61% more data to be transmitted compared to the same signal in QPSK.  However, because of the more efficient error correction, 8PSK requires about the same signal level as DVB-S QPSK!   If signal level is an issue, DVB-S2 QPSK works at almost half as strong signal levels as DVB-S QPSK. 

8PSK modulation constellation

DVB-S2 also adds more complex hybrid modulations, such as 32APSK, or 32 level Amplitude and Phase Shift Keying.  Unlike QAM, which is very susceptible to noise, APSK combines the better noise performance of PSK with the higher levels available in QAM.   Comparing two 16-level constellations- 16APSK and 16QAM, the APSK mode requires 2.6dB LOWER (almost half) power than the QAM signal, and still carries 7% more info. 

The 3rd generation standard, DVB-S3 promises to include even higher levels- up to 64APSK- with dozens of FEC choices and tighter “roll off”, making a sharper-sided signal with more usable bandwidth.  This comes very close to the Shannon Limit, the maximum amount of data that can be transmitted through a channel. 

What does all this mean to you?  DCI‘s engineers UNDERSTAND modulation.  Unlike companies who simply use the same standards that have been around for 15 years, we know all the tricks and tweaks to make a difficult shot work, or optimize a good shot with incredible quality.  While most uplinkers will simply shrug their shoulders if a uplink is breaking up despite maximum power, DCI knows the right adjustments to make.  In fact, on a recent flyaway in Los Cabos, when 6Mhz 8PSK was not working, DCI knew the margins would work at QPSK with 12MHz.  We can also apply the same technology to save money on sat space.  No matter if its a flyaway, satellite uplink truck, or teleport service, let DCI put our extensive know-how and experience to work for you.