I find it annoying when I read short articles that proclaim that a new technology that can deliver faster data speeds is right around the corner. This has most recently happened with 5G cellular, but in the past there have been spates of such articles talking about cable modem speeds with DOCSIS 3.1, and faster copper speeds with G.Fast.
It’s always easy to understand where such articles come from. Some vendor or large ISP will announce a technical breakthrough in a lab, and then soon thereafter there are numerous articles written by non-technical people proclaiming that we will soon be seeing blazing speeds at our homes or on our cell phones.
But these articles are usually premature, and sadly there are real-life consequences to this kind of lazy press. Politicians and policy makers see these articles and accept them as gospel and make decisions based upon these misleading articles. It then is up to people like me to come behind and explain to them why the public claims are not true.
This is happening right now with talk about blazingly fast millimeter wave radios to replace fiber loops. Even if this technology were ready for market tomorrow (which it won’t be), like any technology it will have limits. There are places where wireless loops might be a great solution but other places where it may never be financially or technically feasible. Yet a whole lot of the country now believes that our future broadband is dependent upon gigabit wireless, and this is quashing plans for building fiber networks.
One recent set of these kinds of articles proclaimed that DOCSIS 3.1 is going to bring everybody gigabit speeds over cable company networks. And there is some truth to that, but the nuances are never explained. There are a lot of changes needed in a cable network to bring gigabit speeds to all of their customers. What is really happening in the first upgrade is that cable networks will have limited gigabit capabilities. The companies will be able to deliver gigabit speeds to perhaps hundreds of people in a market. Their networks would have problems if they tried to deliver it to thousands, and their networks would crash if they tried to give fast speeds to everybody.
Consider the list of issues that must be overcome to use a cable network to bring gigabit speeds to the masses:
- First a cable company has to free up enough empty channels to make room for the gigabit data channels. For many cable system this will require upgrading the overall bandwidth of the cable network, and this can be very expensive. In the most extreme cases it can mean replacing all of the network amplifiers and power taps and even sometimes replacing some of the coaxial cable.
- Cable bandwidth is shared by all of the customers in a neighborhood (called a node). If a cable company only sells a few gigabit products in a given node there will be some small degradation of bandwidth performance for everybody else. But if enough customers want to buy a gigabit the cable company will be forced to ‘split’ the nodes so that there are fewer homes sharing the bandwidth. Cable companies today have nodes of 200 – 300 customers, compared to fiber network nodes that generally range between 16 and 32 customers per node. A cable company has to build more fiber and install more electronics to get nodes as small as fiber systems.
- Every network has chokepoints, or places where only a set amount of bandwidth can be handled at the same time. There are several of these chokepoints in a cable network – at the node, on the data pipe serving the node, at several data concentration points within the headend, and with the pipe to the outside Internet. You can’t upgrade speeds without upgrading these chokepoints, and that can be expensive.
- At some point if enough customers want fast speeds the network would need to be fundamentally reconfigured to a new technology. This might mean converting the whole headend and electronics to IPTV. It might mean moving the CMTS (the device that talks to the data at each node) into the field, similar to a fiber network. And it would mean building a lot more fiber, to the point where there would almost be as much fiber as in a fiber-to-the-premise network.
There is always some truth in these technological pronouncements. But these articles are way off base when they then imply that a given breakthrough is the end-all solution to broadband. Yes, cable systems can be faster now, which is great. But DOCSIS 3.1 does not make a cable network equivalent to a Google Fiber network that can already deliver a gigabit to everybody. And yes, there is great promise in wireless local loops. But even after all of the issues with deploying wireless in a real-life environment are solved, the technology is only going to work where there is fiber fairly close to customers and when a number of other factors are just right. These kind of nuances matter and I really wish that non-techie writers would stop telling us that the solution to all of our broadband speed problems is right around the corner. Because it’s not.