In response to TekZilla episode 57, cable systems are more anemic, and fiber better, than you’d think. Here’s the skinny of the standards and speeds:

DOCSIS 1.1 (cable companies still use this tech in most markets): 38 Mbps downstream, 10 Mbps upstream
DOCSIS 2.0 (a few companies, plus a few markets on Comcast): 38 Mbps downstream, 30 Mbps upstream
DOCSIS 3 (the “wave of the future”): DOCSIS 2.0 speeds, multiplied by the number of channels you’re using

On DOCSIS 3, current deployments on Comcast “bond” three downstream channels, but only use one DOCSIS 2 channel for uploads. Technology is being set into motion that will allow for bonding four or even eight downstream channels and multiple (I think up to four) upstream channels for better bandwidth than what Comcast offers right now: 50 Mbps down, 10 Mbps up.

Note that the speeds mentioned above can technically be monopolized by a single cable modem, but in reality have to be shared among all users on a cable “node”, meaning that actual spped will be slower. The number of people on a single node varies widely; in some cases there are as little as 60 to 100 people per node, in other cases several hundred, and in extreme cases a thousand or two. As such, you’re not going to see “full speed” on a given tech pretty much ever. For example, in my area Comcast has DOCSIS 1.1 connectivity, and I get between 18 and 32 Mbps down on speed tests (using PowerBoost, which lets you max out the connection for prety much just long enough to do a speed test) and 2.4-2.8 Mbps up…

Fiber is another story. Verizon’s FiOS system is set up using PON (Passive Optical Network) technology, and they’re using a passive splitter to deliver service to 32 customers per “node”. You *could* put 64 or 128 customers on each node, or more if an “active optical network” was used (like SureWest and a few others provide) but Verizon has 32 subscribers per node. The bandwidth available is just plain crazy when these numbers are taken into account. There are two techs Verizon uses on their network, BPON (Broadband Passive Optical Network) and the newer GPON (Gigabit Passive Optical Network). The speeds are as follows:

BPON – 622 Mbps down, 155 Mbps up
GPON – 2.4 Gbps down, 1.2 Gbps up

These numbers are still shared among all subscribers, however they’re so much larger, and the “sharing factor” so much smaller, that speeds are just plain crazy fast. To give you an idea of the speeds, everyone on a node could be simultaneously using 16 Mbps on downloads and 4 Mbps on uploads, counting system overhead, and the network could handle it. And that’s BPON. GPON doesn’t have the “ATM overhead” and as such all customers could be online at one time, downloading at 75 Mbps AND uploading at 37.5 Mbps, in order to get the network at capacity. Crazy stuff.

Cable, on the other hand, can’t reach the speeds of BPON even with 8-channel DOCSIS 3, let alone GPON. 4-channel-bonded upload DOCSIS 3 can’t beat BPON either. And again, we’re talking about 250 or 500 customers per node versus 32.

So we can see why Verizon, with FiOS, has the HUGE advantage (albeit a costly one depoyment-wise) over any cable company out there who is still relying on coax for the “last mile”. On the one hand you have Comcast, who is just now able to offer a 22 Mbps down, 5 Mbps up tier on DOCSIS 3 (though Cablevision, by having a smaller “node sharing ratio”, is going faster than this on DOCSIS 2), with a very expensive 50 Mbps down, 10 Mbps up option available, all with 250 GB per month caps since, generally speaking, 250 customers or more are on each cable node. On the other you have Verizon, who started out with 52, 15/2, 15/15 and 30/15 (download/upload, megabits per second) tiers when they launched FiOS, then upped the ante to 10/2, 20/5, 20/20 and 50/20 later on, all of this before Comcast’s DOCSIS 3 rollout. Already, looking at Comcast, they can’t go much higher speed-wise before they run into network congestion issues…with their current bonding setup 50/10 is about all that they can reliably get. Even with 8/4 bonding they *might* be able to break 125/50 Mbps down/up before the system crashes. Verizon, on the other hand, can easily scale past 100 Mbps down, 50 Mbps up on their older system, and 4x that on the newer system. Verizon doesn’t want to oversubscribe (like cable systems do) so speeds may be a bit more conservative than what I just mentioned, however they’ve been testing 100 Mbps connections for employees in GPON areas for awhile now.

In conclusion, a lot of small providers (CenturyTel, Windstream, Embarq, NorthState) are running fiber-to-the-home (FTTH) on newer developments, as is AT&T in a very limited respect. Though most of the aforementioned providers don’t offer better speeds over fiber than they do with copper, some do, and in any case fiber-fed developments can easily outrun coax if the heat is turned up.

One more thing: if FiOS isn’t in your area, don’t expect DOCSIS 3 from your cable company any time soon. In most cases, DOCSIS 1.1 provides enough bandwidth that, with network managment, cable companies can sell 20-megabit-per-second down, 2-meg-per-second up connections (but usually less) with minimal complaints about overselling, and they can beat out the phone company if said phone company is using older DSL technology.

In short, competition is very, very good, but when it comes down to it, fiber trumps all.