Slashdot Mirror
L.A. TV Stations Free Up Some Spectrum For Wireless Broadband
alphadogg (971356) writes An effort to free up some of the airwaves used by TV broadcasts and make them available for wireless broadband took a big step forward this week in the U.S. Two TV stations in Los Angeles, KLCS and KCET, have agreed to share a single frequency to deliver their programming freeing up a channel that can be auctioned off to wireless carriers next year. The change, which the Federal Communications Commission calls "repackaging," is possible because digital TV broadcasts don't need the full 6MHz of broadcast spectrum that was used for analog TV.
digital TV broadcasts don't need the full 6MHz of broadcast spectrum that was used for analog TV.
Which is why the signal is worse than analog. Clipping, blocky shadows, dropped signals.
The only time digital has been better was the move to DVD from VHS/Beta and CDs from tape. 78s and 45s are still better than digital.
We will bankrupt ourselves in the vain search for absolute security. -- Dwight D. Eisenhower
Digital gets a little twitchy, you see a still frame (or nothing). Sound becomes silent. It's hard for your brain to actually filter out a blank screen and no audio.
OUtER SPACE THE
Stations which I used to consider viewable (even some which came in at 0 - -10dB of gain, which is perfect for analog) have disappeared outright, or become modern examples of "flickervision" under digital. Don't fool yourself - the broadcast networks would love to see everyone get their signals from cable or via an encrypted stream from satellite. Instead of the fluctuating income stream bounded by ratings and advertiser whims, they can rely on CableCo for a guaranteed, predictable, reliable revenue stream.
So two stations that were previously using 6 MHz bandwidth each, will now share one channel, presumably using 3 MHz each.... and so each will have a 50% drop in picture quality. How is this a good thing for the consumer?
Well, everyone except Joe Sixpack; but he's just an ignorant dolt anyhow (an insensitive clod?).
Digital becoming twitchy isn't just because of transitioning to digital. It's also because they lowered the transmitter power.
So if you were watching an analog signal of the same power, you'd have a hard time making it out too.
(T>t && O(n)--) == sqrt(666)
It'd me so much better if they'd use the full 6MHz for a single channel, rather than two HDs and a standard definition channel. Plus, as others have said, analog was better. Seriously though, no digital cliffs. Oh well. It's not like cable TV goes out during storms with trees coming down and whatnot.
Modern digital television is on even higher frequencies.[than analog UHF]
Not true. Digital television frequencies are basically the same as the analog ones, with some channels either no longer used or no longer used except under special circumstances (e.g. grandfathered stations, low-power stations, etc.).
In practice, most US digital TV stations are UHF stations between channels 14 and 69.
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
KCLS is the Los Angeles Unified School district's vanity money pit TV station (and a PBS member). KCET opted out of PBS programming several years ago because PBS wanted millions and millions of dollars. This deal allows KCLS to save itself the cost of running a transmitter and KCET to have PBS programming (presumably as a subchannel (I have not RTFM)). Plus they get the money from the auction. Pretty smart it seems to me.
In my area, many of our OTA network stations share a channel (due to financial issues, not to free up spectrum). Fox/ABC, CBS/CW, NBC/myTV.
I think most programs have no issues with 12+ Mbps, which usually leaves room for a SD sub-channel. However, shoving two HD programs into a 6 MHz channel leaves each ~9 Mbps. Sports programs suffer significant blocking and pixelation on fast action and pans. Live shows such as America's Got Talent also block and pixelate. Studio shows fare better.
I believe the problem may vary based on market since, I assume, the broadcasts are re-compressed locally and we're at the mercy of the capability of whatever system my money-starved stations purchased. NBC and CBS are the worst here, and I'm not sure if it's their choice of compression hardware or just that 1080i suffers more than 720p.
So basically on these shared channels, you suffer from limited bandwidth, re-compression artifacts (going form 12-18 Mbps down to 9), and local hardware limitations (poor quality compressor, no pre-processing/single-pass only, etc).
With analog you have a gradual variation in quality and can tweak your antenna to get it as good as you can. With digital if your reception is on the edge you get [...] multi-second breakups
Better receivers, such as the box I bought in the coupon era, have a button on the remote that pops up a signal strength meter. I don't know whether that just means raw level of the signal or the actual SNR, but it has helped me aim the antenna to minimize signal dropouts.
Why can't you just go up on your roof and mount a VHF/UHF antenna?
It could be technically the landlord's roof, not mmell's.
Two video streams on a 6MHz channel is two video streams on a single 6MHz channel, not two video streams each with their own 3MHz channel.
That's not relevant.
What is relevant is that you can't squeeze blood out of a turnip.
If you are logically splitting the bandwidth with another broadcaster and you are broadcasting a show that uses 50% of the bandwidth, that only leaves 50% for the other broadcaster. If you want to broadcast a show that requires more bandwidth, such as a typical HD (1080p) television show, it can't do it unless the other broadcaster isn't trying to use more than the remaining bandwidth during that time period.
Assuming you can't get the other broadcaster to cooperate, you can't broadcast with the same "quality" (as defined by resolution and frequency-of-scene-changes) as you could if you controlled the entire 6MHz channel.
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
Spectrum is a finite resource. With one hunk of bandwidth, one TV station can be used by hundreds of thousands or millions of users. Or by one cell phone customer. So now you have this finite resource being gobbled up by phone users "oh, I use cable" cheerful to squander TV bandwidth. It was never a good idea. There is no end to wires, but there is a finite electromagnetic spectrum. Phones over wires, TV over air is the best use. Sadly, everything is now bass ackwards: TV over cables (something that can be distributed on-mass, distributed individually), and phones eating up spectrum (something that is single-use, occupying the spectrum shared by everyone).
Before KCET dropped their PBS affiliation (an idiotic move, but that's another topic)
What are they affiliated with now? Konami Computer Entertainment Tokyo?
I agree with this point
donghogiabao
I don't know whether mmell shares a roof, but I read your comment after having just got back from helping move a relative and her children into an apartment where she does share the building with up to 15 other families.