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Old 26th August 2008, 17:48   #406
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Linuxtechie, you're right. There is no upload in the DTH services we have in India. Even in countries where the service is interactive the dish doesn't do it via satellite. The STB has the provision for a phone/broadband line coming into it. Hence the download happens via satellite and upload using the phone line.
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Old 26th August 2008, 18:01   #407
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Originally Posted by linuxtechie View Post
Agreed, but consider this: the power supply to the STB: 12 V 1 Amp. Hence max power it can generate is 12VA, is that enough to send a signal across atmosphere, into the satellite? IMHO, for that the satellite has to be strong enough to detect feeble signal's coming to it, which IMHO isnot required in case of DTH. In case of broadband they have to use different satellite. However all said, I can be wrong.

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How does a GPS device send signals through the atmosphere ? Even a mobile with GPS does, right ?
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Old 26th August 2008, 18:09   #408
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Originally Posted by esteem_lover View Post
How does a GPS device send signals through the atmosphere ? Even a mobile with GPS does, right ?
???

How Does GPS Work?

Global Positioning System - Wikipedia, the free encyclopedia

Please ponder over the links. Also a bit of googling would also help.

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Old 26th August 2008, 18:14   #409
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Originally Posted by mjothi View Post
I see some (or line of) grains on the T.V. Is it because of the Photo or big screen size? I too have a 29" and so wanted to clarify this.
The lines you see in the pictures are because of the CRT TV's refresh rate. They can only be seen in the photographs, not in real. The cathode ray gun draws the picture on the screen line-by-line. It does that at a certain rate. If your camera's shutter speed is faster than the rate, it captures the process in action and hence you see the bands.
Your eyes don't have a physical shutter like a camera and hence you don't see the lines when you watch TV.

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Originally Posted by linuxtechie View Post
I have been using DishTV for about 4 years now. I was pondering on switch to BigTV for only one reason: HD, however it seems that it is not there yet. Have a HTPC setup at home and DisthTV does look nice, but not really sharp.

The USB thing did catch my attention, but I am very very sure that Reliance won't allow it to be used for recording shows, may be that would yield to copyright infringement or may be it will be some kind of revenue generator for Reliance.

Finger crossed.

~LT
LT, you're right again. No service offers HD signals in India. Heck even the regular signals from Dish and TSky are sub par when seen on a Hi-Def TV - nowhere near DVD quality as they claim. That's perhaps what you encounter on your PC.
I don't know about Reliance. I too have big hopes from them given that their STBs have all the requisite features but I'm not hopeful. I'd think, at the moment, they'd all be the same in terms of quality. Reliance's STBs perhaps are just future-proof. When they do offer a superior service, their customers may not have to change the hardware.
The reason I asked Anuj about what TV his BiG DTH is attached to, is because on a CRT all the DTH services look great. The difference shows up on a Hi-Def LCD TV. I have a 32 inch Sony LCD and if I view it from 2-3 feet away I can see pixellation and blotches all over the picture on my TSky connection. 6-7 feet away it looks fine.
The same doesn't happen with a DVD. Even at 480p or whatever res a DVD operates at, the picture looks crystal clear at whatever distance. Obviously, these signals are far from DVD quality.
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Old 26th August 2008, 18:24   #410
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I do not think asymmetric authentication can explain it all. The servers can not be broadcasting the 1000s of recharge coupon numbers being sold across the country all the time.

The server has no way of knowing when the user will switch on the box. Hence it will have to keep transmitting the updated key all the time till the box comes online and validates. Also, thereafter the server will still not know that the validation has happened. So it will keep doing the same. Now considering all those 1000s of coupons I do not find that feasible somehow. A much simpler solution is a very small data exchange at the exact time when required. Kindda handshaking.

SMS? You mean SMS as used in cell phones? On whose account? Where is the SIM? Its not that. The SMS is via satellite. As I conjectured earlier, a short handshaking.

And channels/movies on demand are not through filled up forms. They have a library. You can request for a movie from the library at the appropriate time. Accordingly it downloads the movie for you to see. Also, the cost is adjusted in your account. Depending on the movie (new/old/classic/hollywood etc) the prices also vary. The right amount is deducted from your account.

Finally, the 12VA signal should not be a problem really. You do not really need huge powerful transmitters for sending such small pulses. As EL said, small hand held GPS devices send your positions to the tracking satellites and download the correct map accordingly.

About satellites, yes, that I agree. In fact as I mentioned in the previous post the satellite or at least the transponders will probably have to change to support huge bandwith for broadband connectivity. Even if the dowload only happens via satellite (and upload via terrestrial lines) it will mean humongous bandwidth requirement. That will in all probabilities mean a change in satellite and/or transponder type/band.
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Old 26th August 2008, 18:25   #411
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Originally Posted by esteem_lover View Post
How does a GPS device send signals through the atmosphere ? Even a mobile with GPS does, right ?
nope, it does not. It is a receiver only. It figures out your positiion by triangulating the signals from the three GPS satellites.

How Does GPS Work?
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Old 26th August 2008, 18:29   #412
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We have satellite phones which must necessarilly be transmitting to satellites overhead, so I'm guessing it doesn't take that much power to transmit to a satellite.

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How does a GPS device send signals through the atmosphere ? Even a mobile with GPS does, right ?
Hi EsteemLover, in case of GPS it's the GPS satellites that do the transmitting. The GPS devices just need to receive, reception from 3 satellites is sufficient for them to triangulate.
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Old 26th August 2008, 18:41   #413
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Originally Posted by Zappo View Post
I do not think asymmetric authentication can explain it all. The servers can not be broadcasting the 1000s of recharge coupon numbers being sold across the country all the time.

I dont know exactly how this works but with TSky you call them give them the code and they activate the service. Which means the satellite just sends a `ok' signal to the STB. What the satellite possibly transmits is just the `ok' or `not ok' signal. And Im sure there is a simple, logical way to club/compress this data.

A much simpler solution is a very small data exchange at the exact time when required. Kindda handshaking.

I can assure you there is no data exchange.

SMS? You mean SMS as used in cell phones? On whose account? Where is the SIM? Its not that. The SMS is via satellite. As I conjectured earlier, a short handshaking.

With TSky you register a number with the account. When I call from it or send an SMS they know from which subscriber it is.

And channels/movies on demand are not through filled up forms. They have a library. You can request for a movie from the library at the appropriate time. Accordingly it downloads the movie for you to see. Also, the cost is adjusted in your account. Depending on the movie (new/old/classic/hollywood etc) the prices also vary. The right amount is deducted from your account.

There is no download. The movie is being broadcast all the time. When you choose to watch one by calling them or sending an SMS, the server sends a signal via satellite which unlocks the movie channel for 24 hours.
If the service was interactive then I should be able to watch the movie anytime I choose. Say like now 6:37pm. But that is not the case. There are set start times - every hour or so. And I have to choose the time when I buy a movie.

Finally, the 12VA signal should not be a problem really. You do not really need huge powerful transmitters for sending such small pulses. As EL said, small hand held GPS devices send your positions to the tracking satellites and download the correct map accordingly.

As I said earlier, GPS devices don't send signals. they only receive.
Im sure internet resources will be able to explain this better.

Last edited by StarScream : 26th August 2008 at 19:00.
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Old 27th August 2008, 09:13   #414
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Signal get lost in BIG TV too when it rains...

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Originally Posted by condor View Post
Anuj, thought you would have done the rain-testing last night. Do let us know when you do it.
Yesterday It was raining heavily and I was watching some channels in Big TV. When I changed the channel message display due to rain or other atmospheric reason signal is not coming.

But when you surf the list of channels, some or other channel comes randomly.

So, BIG TV is also same as Tata Sky. When it rains heavily, signal get lost.

On the other part, it seems this thread become too TECHNICAL in its discussions. From Set Top Box to GPS to SMS etc. I feel these are off topic discussions happening here. There is huge DVB specification available freely on internet, without knowing specification commenting on technical aspects of DTH would yield no result. I request members please discuss only DTH aspects in it.
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Old 27th August 2008, 11:11   #415
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Quote:
Originally Posted by anujmishra View Post
Yesterday It was raining heavily and I was watching some channels in Big TV. When I changed the channel message display due to rain or other atmospheric reason signal is not coming.

But when you surf the list of channels, some or other channel comes randomly.

So, BIG TV is also same as Tata Sky. When it rains heavily, signal get lost.
Umm. I was about ask you this when I was seeing those huge rains
So, should we stay with the cablewala?
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Old 27th August 2008, 11:56   #416
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Quote:
Originally Posted by mjothi View Post
Umm. I was about ask you this when I was seeing those huge rains
So, should we stay with the cablewala?
I will give you reasons not to stay:

1. If power is gone in the cable wala's region, he may or may not have inverter and hence u can;t watch tv.
2. According to cablewala's whim, some channel may disappear, go to different slot.
3. Depending upon the issue with Service Provider, the cablewala may discontinue some channel without notifying.
4. On average, roughly some 40 % of channels have great quality, rest all are pathetic.

Convincing enough eh?

~LT
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Old 27th August 2008, 12:32   #417
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Quote:
Originally Posted by mjothi View Post
Umm. I was about ask you this when I was seeing those huge rains
So, should we stay with the cablewala?
No, I don't see point to stay with cablewala. Even outage duration during rain is not significant (As per my first expereince). It goes off for 1 - 2 minute and then come again and stay. This is common phenomena across the world in all DTH platforms.

But most of the time you will get very good quality of picture and sound.

Even if you are paying Rs. 200 per month rent to cablewala, at the end of year you will be saving Rs. 200 when you take DTH connection as of now.
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Old 27th August 2008, 12:50   #418
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Rain outages are few & far between, DTH is wayyy better than the local cablewallah. Thanks guys for the pointers but my ageing brain still does not understand any of it.
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Old 27th August 2008, 12:52   #419
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Quote:
Originally Posted by anujmishra View Post
No, I don't see point to stay with cablewala. Even outage duration during rain is not significant (As per my first expereince). It goes off for 1 - 2 minute and then come again and stay. This is common phenomena across the world in all DTH platforms.

But most of the time you will get very good quality of picture and sound.

Even if you are paying Rs. 200 per month rent to cablewala, at the end of year you will be saving Rs. 200 when you take DTH connection as of now.
My experience with rain outages in Shillong is that if there is very heavy rain, there will be some disruptions in services but it will be for a few minutes at most. The maximum disruption I have had in 2 years of using their service has been 10 minutes. This is way better than having to deal with the cable mafia who will try to loot you at every opportunity. This holds true for all DTH operators when compared to cable operators.

However, it will be foolish to think that Reliance will not raise the prices of their services once the teething problems have been sorted out and the inaugural offers are over. How can you provide a service for nearly half the price of what your competitors are offering. Moreover, the DTH operator has to pay the broadcasters and this is quite transparent. Its not that BigTV is getting the same package from the broadcasters for half the price that of TataSky, DishTV and SunDTH! Its only a matter of time.

The main objective of shifting from cable to DTH is to get a better level of service in the form of clear picture and sound. In some cases, cable is much cheaper when compared to DTH, both in hardware costs and monthly subscription and to an extent service quality. Another advantage of DTH is that you don't have to be at the mercy of the cable operator when there is a cable breakdown or power failure.

Just my 2 cents.
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Old 27th August 2008, 13:37   #420
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Quote:
Originally Posted by anujmishra View Post

Here are the pics of BIG TV set top box and some screen shots. Movie channels still not activated would have to call customer care for that.
Tata Sky also has a logo at the bottom right of many channels. But that logo is semi transparent, and smaller than this Big TV logo.


Quote:
Originally Posted by esteem_lover View Post
Rain outages are few & far between, DTH is wayyy better than the local cablewallah.
Yes. I completely agree with you. We have a cable connection with Set Top box at our home (cannot get DTH due to direction problems, and society is not allowing antenna on terrace). The service is pathetic. Many channels are not available even on the STB. The signal disappears at the cablewallah's will. Picture is highly pixellated. We get Discovery channel only in Hindi on the STB. And Animal planet has English as well as Hindi audio simultaneously. Many say that DTH's customer service is not great. But our cablewallah is no different. We have been complaining about the audio for FIVE months, but the reply is standard "We do not have the required software".

In comparison, Tata Sky at my native place is extremely trouble free.
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