Does TV Over The Internet Actually Reduce Last Mile Bandwidth Requirements?
from the to-some-extent dept
It looks like Tom Evslin is kicking off another interesting series of posts. This one is about the bandwidth requirements needed for next generation internet offerings, with a specific focus on video over the internet. This has obviously been something of a concern to many, with various warnings that the internet faces near certain collapse if changes aren’t made. While Evslin does admit that there’s backbone capacity that needs to be dealt with (on which he promises more details in future posts), he points out something that many people probably haven’t realized. When it comes to the last mile, routing TV over the internet could actually decrease the amount of bandwidth needed — at least when it comes to cable systems (which is part of the reason you don’t hear cable companies complaining as much as telcos these days). Current cable systems deliver 200 or so channels to your TV system simultaneously. In other words, all that bandwidth is already there — just not using the internet. If you switch to delivering the content over the internet, you no longer need to deliver all 200 channels all the time, but can simply deliver the content more “on demand.” That decreases the bandwidth needed towards the end of the network. Obviously, there are still concerns about other parts of the network (as well as what it would take for cable providers to shift existing infrastructure to support TV over the internet), but it’s still an important point as people discuss whether or not the rise of video online is a huge threat to the overall internet.
Comments on “Does TV Over The Internet Actually Reduce Last Mile Bandwidth Requirements?”
If I could watch teevee on my computer I probably would. Currently I don’t watch any teevee because my monitor would be blocking my view.
Good Job
Way to twist that debate around! 🙂
I wish more people would use simple logic like this when examining “supposed” problems of the internet.
Another point I was thinking about was how so many people are worried about Sexual Predators on the internet. In all actuality that’s exactly where we want them. I would much rather predators spending time “virtually” practicing their habits. If they happen to cross the line and act on their thoughts in real life then we have a perfect way to track them with their internet history.
A win win situation no?
you know..
Advertisers would REALLY love this, think about it. No more pointless ‘studies’ to figure out who is watching what, they would have actual statistics ’11million people were watching Heroes at nine pm, 37% of them changed channel during commercials’.
AS it stands
My son has a pretty good test bed; he gets tv, internet and phone from the cable company. When he has a lot of activity on the internet, his phone cuts in and out. when he is told, he will stop a couple of instances and it becomes bearable. Obviously his cable is to maximum throughput. weather or not his available bandwidth would increase if tv was shifted to the internet, I can’t say, but he would find a way to use it up.
Re: AS it stands
Your son needs a new router which supports QoS better. A proper router will prevent this from happening. I suggest a router compatible with dd-wrt. Also, the cable companies limit the upload rate on their lines. Not because they are out of bandwidth, but just to discourage running home servers. Unfortunately, this is the bandwidth the phones need the most. This is also the bandwidth file sharing software uses too.
helping other things
I can see how this will help other things too. We currently have the full digital cable with Internet. We get ghosts on several channels. G4 has wavy lines threw it. (really makes my head spin) I can’t get SciFi at all. Digital cable my ass.
If its switched over to IPTV, and it bypasses the download cap, I wouldn’t have any of these problems. No more digital signal running on top of analog. But we all would need cable boxes.
Re: helping other things
FYI, if it’s like here, TWC doesn’t provide “basic” channels via digital delivery. That’s pretty much SciFi, HGTV, CNN, Comedy Central, etc. All of these channels are still over analog cable channels, but your “digital” box doesn’t really tell you the difference. Premium channels and upper-tier are typically digital.
Re: Re: helping other things
Our SciFi is digital (Chan. 127). So are the other channels with the ghosts. Except G4, that channel sucks all over.
I think I already know the answer to this but I’ll ask anyways. How can a digital and analog signal occupy the same cable without overlapping and causing interference? I asked a tech at Comcast but they couldn’t answer me.
Re: Re: Re: helping other things
Frequency-division multiplexing. Each channel on the cable plant is its own little 6 MHz slice of heaven, and the headend can put any kind of signal it wants into that 6 MHz. So it puts upstream DOCSIS digital data down below Channel 2, analog video signals on channels 2-78, a downstream DOCSIS digital data channel in one of the channels above 78, and multiplexed MPEG-TS digital video signals on the rest of the channels above 78.
Re: Re: helping other things
Cogeco in here in Ontario, Canada delivers all channels, basic and premium, in digital format. The analog versions of the basic channels are also available and are remapped to the 900s on our digital cable boxes. I’m not sure why they bother remapping them since the picture quality is inferior to the digital versions.
Can't possibly do it all
For years greedy companies have just kept dumping more and more tasks onto the existing infrastructure. Whether we like it or not, the internet is a finite source that requires more investment to increase capacity. VOIP has become a real load just like streaming video. Just because we have the ability to make these things available doesn’t mean that they will al function flawlessly. As “Needs some help” stated proper routers and hardware at the end users connection are a tremendous help. Sadly many of the end users are just to dumb to understand. Many users have just enough technical knowledge to be a pain in the butt for everyone else. Their inept use of technology put strains on the system that cause slowdowns for everyone. Of course I really believe the main problems are the companies that keep piling more and more data onto the internet with no meaningful investment in the infrastructure on their part. Perhaps we need a system where the VOIP providers for example and the hardware manufacturers had to pay a percentage toward future investment in internet infrastructure to support the increased load they place on the system. Of course then there would always be the danger of governments wanting to get involved. After all lest we forget, Al Gore took credit for inventing the internet (Yeah right ) like he was ever anywhere near technically literate to do more than send e-mail.
Re: Can't possibly do it all
Video is the biggest future threat to internet bandwidth. Especially with online movie rentals/purchases becoming increasingly popular and available. Typical voip uses 90K or less when in use and next to nothing when not. The biggest waste of bandwidth is Spam and poorly patched/infected systems. I’d like to see that waste go away.
Paying into infrastructure is a great idea, however who do we pay? I don’t think charging content providers (voip, youtube) is the right idea, charge the end user by charging the ISPs more. The ISPs will pass this to the user.
COMPLETELY WRONG -->Tech Freak
We have a market system, we have technological advances in bandwdith and routing almost yearly. (10Gigabit etc)
The idea that anyone other than the pipe providers should pay for the pipes is just silly.
If you use lots of power, does that mean you also have to pay for the power lines from the generation plant to your house? Of course not you pay your power bill and the electric company pays the rest.
Network providers will continue to upgrade their networks to provide more bandwidth because they have to. If they don’t someone else will…and that’s what sucks about being a network provider, they are a commodity utility nothing more. The only real leverage they have is last might right of way and government sanctioned monopolies.
If ISP really though this was going to be a problem they would allow and implement multicasting across the internet to reduce the bandwidth load. But they have not, do you know why? because they like you using more bandwidth. They do not want you to use less, but they do want you to think there is this huge crisis so that they can scare people and government into allowing them more money for a service they already provide.
Re: COMPLETELY WRONG -->Tech Freak
Absolutely. I’m a network infrastructure engineer and I can tell you that the only reason bandwidth costs as much as it does is because of the right of way monopolies certain companies enjoy.
Fair enough
Needs I agree. I was simply using VOIP as an example. Your Video example is more accurate and streaming video I acknowledge as a huge problem. My intent with paying into infrastructure was aimed at the companies like Vonage, and the Video download services etc who offer these services. I would support a fee system where the consumers paid a share as well since we all use the system. That would indeed be fair enough for all of us. I simply want to see the companies who make the hardware and advance software to offer such new technologies pay a proportional share since they profit from it. Youtube and such should not be involved since they neither manufacture component hardware or created the software, they merely make use of what is already there. We on the other hand as consumers are the ones who create the demand and should be willing to shoulder our share of the costs invloved. Though I admit that I feel most ISP’s at least the cable and DSL providers are already pushing the envelope with the rates they charge consumers for the service provided. Even though they do have an investment in their infrastructure to get the service to us. Your points are more than valid and well taken.
Re: Fair enough
I fully support the arrangement proposed by Fair Enough.
I only think it’s right that the users help support our infrastructure, umm, I mean the internet. Yeah, forget about all the money that the government gave us to build out infrastructure, that went to executive compensation packages and other ‘important’ investments, I mean it’s not like anyone really wants fiber to the home, right?
While we are at it, we could also charge the content providers that provide the majority of the traffic that flows over our pipes, umm, I mean the internet (boy, tough keeping those things seperate, paid for by govenment subsidy, but we did build some of the infrastructure we were supposed to, so technically they are ‘our pipes’ and we should be able to prioritize and charge accordingly for the information flowing over them, right?
Network neutrality? Bah, who needs it, let us telco’s have the control, and we’ll make sure that you get the information from the content providers who pay us the most (that’s ‘quality of service’ prioritization for those of you unfamiliar with the issue – he who pays the most will be seen/heard the most, while those providers who don’t want to pay for ‘quality of service’ will still be available (with delays and dropouts added of course, since they aren’t paying the ‘quality of service’ enhancement fees that we charge).
Ok, I gotta get back to work reforming our monopoly. We had a good thing until the government broke us up, good thing they are letting all these mergers fly back thru without proper review… We’ll have our monopoly back in no time, and the people won’t even know what happened, but once we are back, they will know by the increases in cost and decreases in service as we prioritize all traffic using our patent pending ‘quality of service’ routing techniques… here is an example, but remember this is patent pending.. Priority ratings (1 = highest): Our network traffic or info we want users to se = 1, 5 highest paying content providers (those who pay the most for ‘quality of service’ guarantees) = 2, next 5 highest paying providers = 3, …. All other ‘regular’ internet traffic = 99)
Math doesn't add up
The average house has average 2.5 TVs. The average cable operator broadcasts their TV to in some places from 500 to a 1000 homes (passed). Say that only 70% have cable. So that is 350-700 homes. If you have only space for say 200 simultaneous channels that means of the 875-1750 homes only 200 can be watching TV at the same time. If you add HD TV the numbers should be worse.
So you will need a rebuilding of the cable infrastructure to handle this.
Also if you look over DSL – the individual line speed becomes problematic especially with HD.
Re: Math doesn't add up
First, even on existing systems, you have space for about 400 channels – typically, 83 analog channels (52-550 MHz) and 306 digital channels (550-860 MHz, 6 digital subchannels per 6 MHz channel, less one 6 MHz channel for DOCSIS downstream data).
If all a cable company did was to eliminate analog channels and use every channel (but one) for digital video, that would give them 810 channels.
Because the cable system is broadcast, every STB gets every subchannel, and picks the one (or two) to decode.
So your 875-1750 TVs could all be on and watching at the same time – as long as they’re not watching more than 810 different programs.
Re: Math doesn't add up
Bzzzt. Wrong. They can only be watching 200 _different channels_ at the same time.
Wrong again. You should quit trying to play engineer now.
Re: Math doesn't add up
You multicast the IPTV streams
What % of available bandwidth on the average cable system is currently devoted to IP?
I have been told that only 5% of the capacity is used by internet, so that would make the average home capable of downloading at a speed of 100 megabits ps if the entire network was devoted to IP. (correct??) If thats true then the cable companies can send 4 HD signals, several SD signals, internet, and phone all over the same line, all on-demand, all simultaneously; If they so chose to make the infrastructure upgrades, and consumer upgrades.
Re: Re:
DOCSIS 2.0 provides 38Mb/s downstream capacity in a single 6 MHz channel. DOCSIS 3.0 enables bonding of multiple 6 MHz channels. If someone build a DOCSIS 3.0+ CMTS and cable modems that enabled bonding of all 135 available channels, the theoretical downstream throughput would be just north of 5 Gb/s.
With 500 households on a node, 60% subscribing, that would be an allocation of 17 Mb/s per household.
Which doesn’t sound like a lot, until you do the math for what’s there currently – 38 Mb/s shared among 50% of those 300 households that are cable customers gives an allocation of about 250 kb/s per household, but that’s enough for cable companies to offer (and usually deliver) 6Mb/s service.
Ah, the wonders of overbooking.
DG Lewis did you account in your calculations that not everyone is going to be utilizing the network at the same time? That should definitely relieve the load.
Bandwidth Buyers Guide
what if they sell me only the channels I want?
Can somebody tell me how much bandwidth will be saved if the cable/sat companies sold their services by channel and not by these moronic bundles/packages? Out of the 170+ channels I get from Dish I probably use less than 10 regularly and maybe another 5 or 6 infrequently. Of course charging a la carte, they won’t make as much money…