Currently unavailable. Please try later.

jcarrera

SatelliteGuys Pro
Original poster
Dec 15, 2006
901
0
Florida
Recently, I have been hitting lots oc channels where a message appears: "XXXX is currently unavailable. Please try again later."

This used to NEVER happen. What has changed that now produces this failure to deliver programming that is in our package?
 
Welcome to the world of Switched Digital Video.

First lets find out how SDV Works. SDV works similar to on-demand or say youtube (in laymans terms) There is a server at the "hub" and a set amount of "channels" 6mhz wide carriers)

Normally what happens is the BHN sends out every single channel on a carrier at once. 1 Analog channel takes up an entire "carrier" on its own. 10-15 Digital Channels can take up a single "Carrier" and up to 4 (depending on compression and activity ala sports vs say static images) HD Channels per carrier.

That means cable companies are limited to the number of channels they can offer based on the available "carriers" Since most cable systems (BHN being one of them) Are 750mhz systems (BHN Tampa I believe has upgraded to at least 870 maybe even 1ghz) And each Carrier is 6mhz wide and the first 50MHZ is set aside for return, that leaves a limited number of free carriers.

So what the cable industry has come with is a simple solution called Switched Digital Video (SDV) What it does is instead of sending out EVERY channel it only sends out the channels people request. So this way they can offer "100s" of channels but not need the space for them. As they only take up space when someone watches it. It "streams" the channel to the customer as they tune to it.

The problem is however when to many people want to watch to many different channels at once. The least popular channels are the ones on SDV however there are channels like starz etc on there also.

BHN was not at all prepared for the high demand and strain on the system, as they put way too many "nodes" (A node normally feeds a neighborhood of up to 500 passings or fewer) per "server" So what they have begun to do is upgrade and change this.

So as they upgrade it will be 1 for 1. 1 Node per server, thus giving way more space and eliminating that "cant see channel at this time" message. They are doing this at the same time of preparing the hubs for DOCSIS3 (wideband / lightning) but it is happening. They are also physically splitting several nodes based on "box" count (how many cable boxes a node feeds) Where as before node splits were only done based on modems (because only modems used "bandwidth" and needed free space) Now Boxes work similar in theory to the modems and traffic is important to monitor.

So nothing you can do or BHN really until the upgrades and node splits are done. The only thing you can really do is just keep trying the channel and wait till you get a free spot.

One problem is people will turn on an HD channel and when done watching TV turn off the TV but not the box. So in turn their cable box is still using that space for the HD channel even though no one is watching.

Its a problem ALL cable companies are running into and it simply requires them to upgrade the backbone. Which BHN is doing. Trust me I know ;) Hub techs are working 30-40hours OT a week to get the network upgraded. It can only happen so fast as its a lot of work to do, and it has to be done in stages to limit impact. And to catch problems before you get to far along.

Anyway a bit long winded but hope it helped.
 
Maybe they should have upgraded BEFORE going to SDV, huh?

I really like not getting the channels I want to watch.
 
Maybe they should have upgraded BEFORE going to SDV, huh?

I really like not getting the channels I want to watch.

I have noticed while waiting for a channel to become available; it is generally quicker to get the channel by using the channel up or channel down button, than actually selecting the channel from the program guide or directly imputing the channel number. Whether it is just a coincidence or not, I am not sure. However SDV can definitely be frustrating at times.
 
Maybe they should have upgraded BEFORE going to SDV, huh?

I really like not getting the channels I want to watch.

It was simply a case of under estimating demand. Not to mention a case of the people at the top demanding more get done faster then possible. They wanted to say bhn has 100 plus hd channels by a certain date. Its what happens when people who never worked in the field run a company.
 
You are telling me BHN did not know how many people watched each channel by time? Your advertisers are gonna be interested in knowing that!
 
Again you miss the point of channels they never had before. They only added the extra HD After they had SDV, (as they didnt have the space before) So they had no benchmark to base the popularity or viewership on there system of those channels as they never had them before.

Also advertising rates are determined just like they are on network channels etc. The Ratings system. Nielson and the likes.

And of course once the ball was rolling they certainly could not just turn off the channels and wait till they build more capacity.

So yes it was clearly poor planning on their part.
 
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Of course, the channels I am getting the "XXXX is currently unavailable" on are not the new channels. But I guess the new channels are eating up the insufficient bandwidth, and old channels are cut off because of that.
 
they didnt just put the new channels on the SDV. They based it more off of how many people watch it since only so many can view the said program at a time. Therefore some of the "new" hd are on regular carriers and some of the "old" channels are on the SDV carriers.

Orlando is still running on 750 mhz??
In tampa, the equipment is rated to 1ghz but I think the highest were running is like 865mhz right now.
 
they didnt just put the new channels on the SDV. They based it more off of how many people watch it since only so many can view the said program at a time. Therefore some of the "new" hd are on regular carriers and some of the "old" channels are on the SDV carriers.

Orlando is still running on 750 mhz??
In tampa, the equipment is rated to 1ghz but I think the highest were running is like 865mhz right now.

Yes Orlando is still running at 750 (we do go a few channels past it though, pushing our 750 gear to the limits.) We are not as special as tampa to get a brand new plant....

And everyone can watch said program at once. The SDV limit is not how many people can watch a single program, but how many Different channels can be watched at once.
 
I am beginning to see and to hear about more and more SDV limitations, and it is confirming my propensity to not like it at all. Maybe good for BHN; value to customer is beginning to be questionable.

Is it better to have more channels available to you, but not be able to watch something you want to watch on one of those channels? I tell you from personal experience, the "Currently unavailable..." message is one huge downer. When I get it, I don't sit there thinking, "boy, I'm really happy I have all these channels." No indeed, that is not at all what I am thinking about BHN at that point in time.
 
Yes Orlando is still running at 750 (we do go a few channels past it though, pushing our 750 gear to the limits.) We are not as special as tampa to get a brand new plant....

And everyone can watch said program at once. The SDV limit is not how many people can watch a single program, but how many Different channels can be watched at once.
You may be correct, but what I learned when they started running it was that the reason they put the not so popular channels on it was because there was a limit to how many could tune in at a time (im sure that limit is quite high but a limit none the less).

I also can see how there would be a limit to the amount of channels at a time since there are only so many sdv frequencies although I personally havent ever ran into that issue, at my house or a customers. (we may also have more frequencies do play with so that may be part of the reason). Whenever I see the not available, try again later there is a signal issue at the home causing it or a faulty box.
 
You may be correct, but what I learned when they started running it was that the reason they put the not so popular channels on it was because there was a limit to how many could tune in at a time (im sure that limit is quite high but a limit none the less).

I also can see how there would be a limit to the amount of channels at a time since there are only so many sdv frequencies although I personally havent ever ran into that issue, at my house or a customers. (we may also have more frequencies do play with so that may be part of the reason). Whenever I see the not available, try again later there is a signal issue at the home causing it or a faulty box.


Its not a limit to how many people can tune in at a time, every single customer in a node can tune into the same SDV channel at one time and have 0 problems.

Heres how it works, there are a set number of "channels/frequencies" setup to use SDV, lets for simple terms say channel 1 2 and 3 are the SDV channels.

Lets say there are 100 people in a node.

Now lets say one person wants to watch channel Z. So they tune to channel Z and it uses SDV channel 1 to send. So now SDV channel 1 is streaming Channel Z. Now when a new user wants to watch channel Z also they simply pick up the already going stream. All 100 users can watch channel Z at once, because it does not matter if one person or 100 are watching channel Z. Its already been picked.

Now lets say someone else wants to watch channel Y. So then channel Y comes on SDV channel 2.

So then another person wants to watch channel Q. Channel Q comes in on SDV channel 3..

So now there are three channels being viewed, even if only three people are watching TV (one on each of those channels) Anyone else who comes along will only be able to see those three channels. If they try to view another they will get the error message saying "unavailable"

But that person can watch any of those three already streaming channels without problem. So could the rest of the 96 people in the node.


Of course that is a really basic explanation, if we want to get technical A single "channel/frequency" (6mhz wide) has *about* 45mbit worth of bandwidth. Which means that single channel can stream about 3-4 different HD channels (depending on compression and activity) , or 10-15 Standard digital channels..

So those three channels we talked about early could literally have 30-40 different "channels" on them.

Now this "limit" is only "per *server*(beq) So its not all of brighthouse. A BEQ can have several nodes, or just one node (A node feeds a neighborhood typically 500 or less passings)

The problem as mentioned before was BHN put to many nodes per "server" They are fixing this and once they are one for one, the "unavailable" message will certainly be a distant memory. As there is tons of bandwidth available by doing this. Not to mention as they more one analog to SDV (They also usually make that QAM the channel was on an SDV QAM thus turning that one analog channel into a place for upto 15 digital)

Anywho my fingers hurt.
 
Insider, great explanation. Sorry about your fingers.

That explains technically why it happens. The results are still a bummer, although I have not seen it for over a week now.
 
yeah, man, but I was getting those messages on channels like AMC and SyFy and History. popular channels it is almost unheard of to be locked out of.
 
Im not sure where your at, but all three of those are SDV here in tampa.

Insider, that makes sense. Thanks for the info there! I wonder if they have done the node upgrades here. I havent seen that message in months from an SDV issue unless its an obvious poor signal thing.
 
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