How Much Speed Do We Really Need?

There is a lot of buzz floating around in the industry that the FCC might lower the official definition of broadband from 25 Mbps down and 3 Mbps up. Two of the current FCC commissioners including the chairman opposed setting that definition a few years back. Lowering the speeds would let the FCC off the hook for the requirement by law to make sure that the whole country can get broadband. If they lower the definition, then voila, millions more Americans would be declared to have adequate broadband.

So today I thought I’d take a look at the download speeds we really need at our homes. You may recall that back when the FCC set the 25/3 Mbps definition that they made a list of the broadband speed needed to do typical activities. And in doing so they tried to create profiles of some typical American households. That attempt was awkward, but it was a good starting point for examining household bandwidth needs. I’m updating their list a bit for things that people do today, which is already different than just a few years ago. Consider the following web activities:

  • Web Background 5 Mbps
  • Web Browsing 1 – 2 Mbps
  • Online Class 1 – 2 Mbps
  • Social Media 1 – 2 Mbps
  • Streaming Music 3 Mbps
  • Voice over IP 2 Mbps
  • SD Video stream 1 – 3 Mbps
  • HD Video Stream 4 – 6 Mbps
  • 4K Video Stream 15 – 20 Mbps
  • Gaming 1 – 3 Mbps
  • Skype / Video Conference 1 – 3 Mbps
  • Big File Downloader 50 Mbps

People don’t agree with all of these listed speeds because there are no standards for how the web works. For example, by using different compression schemes a video stream from Netflix is not identical to one from Amazon. And even from one source there is variation since an action move takes more bandwidth than something like a stand-up comedy routine.

It’s important to remember that broadband demand can come from any device in your house – desktop, laptop, smartphone, tablet, etc. It’s also important to note that these are speed requirements for a single user. If two people in the house are watching an separate video, then you have to double the above number.

What the FCC failed to consider back when they set the speed definition is that households need enough bandwidth to handle the busiest times of the day. What matters is the number of simultaneous activities a home can do at the same time on the web, with most families being busiest in the evenings. There might be somebody on social media, somebody watching an HD movie, while somebody else is doing homework while also using a smartphone to swap pictures.

There is another issue to consider when trying to do simultaneous tasks on the Internet – packet loss. The connection between the ISP and a customer gets more congested when it’s trying to process multiple data streams at the same time. Engineers describe this as packet collision – which sounds like some kind of bumper-car ride – but it’s an apt way to describe the phenomenon. Most home routers are not sophisticated enough to simultaneously handle too many multiple streams at once. Packets get misdirected or lost and the router requests the missing packets to be sent again from the originator. The busier the router, the more packet interference. This is also sometimes called ‘overhead’ in the industry and this overhead can easily grow to 15% or more of the total traffic on a busy connection, meaning it takes 15% more bandwidth to complete a task than if that task was the only thing occurring on the broadband connection.

There is another kind of interference that happens in homes that have a WiFi network. This is a different kind of interference that has to do with the way that WiFi works. When a WiFi network gets multiple requests for service, meaning that many devices in the home are asking for packets, the WiFi router gets overwhelmed easily and shuts down. It then reinitiates and sends packets to the first device that gets its attention. In a busy network environment the WiFi router will shut down and restart constantly as it tries to satisfy the many needed devices. This kind of interference was designed into the WiFi specification as a way to ensure that WiFi could satisfy the needs of multiple devices. This WiFi overhead can also easily add 15% or more to the network demand.

Anybody who lives in a home with active users understands how networks can get overwhelmed. How many of you have been frustrated trying to watch a movie when others in the house are using the Internet? Even big bandwidth can be overwhelmed. I have a friend who has a 100 Mbps fiber connection on Verizon FiOS. He went to watch a video and it wouldn’t stream. He found that his two teenage sons were each using half a dozen gaming streams at the same time and had basically exhausted his fast bandwidth pipe.

The FCC can tinker with the official definition of broadband since that is their prerogative. But what they can’t do is to define for any given home how much bandwidth they really need. The funny thing is that the big ISPs all understand this issue. The cable companies have unilaterally increased speeds across-the-board to urban customers several times in recent years and in most markets offer speeds considerably faster than the current FCC definition of broadband. These ISPs know that if they were only delivering 25 Mbps that they would be overwhelmed with customers complaining about the connection. Those complaints are the real proof of how much bandwidth many homes need. If the FCC lowers the definition of broadband then they have on blinders and are ignoring how homes really use broadband today. If they lower the speed definition it’s hard to see it as anything other than a political move.

Our Degrading Networks

cheetah-993774Lately I’ve been hearing a lot of stories about rural broadband with a common theme. People say that their broadband has been okay for years and is now suddenly terrible. This seems to be happening more on DSL networks than with other technologies, but you hear this about rural cable networks as well.

There are several issues which contribute to the problem – more customers sharing a local network, increasing data usage for the average customer, and a data backbone feeding the neighborhood that is has grown too small for the current usage.

Broadband adoption rates have continued to grow as more and more households find it mandatory to use broadband. And so neighborhoods that once had 50% of homes using a local network will have grown to more than 70%. That alone can stress a local network.

Household broadband usage has also been increasing. A lot of the new usage is streaming video. This video doesn’t just come from Netflix but there is now video all over the web and social media. It’s hard to go to the web today and not encounter video. As more and more customers are using video at the same time they can quickly be asking for more aggregate data in a network than the network can supply. Where the demand has outstripped network capability there is a remedy available for most situations and increasing the size of the bandwidth pipe feeding a neighborhood will typically fix the problem.

Let’s look at an example. Consider a neighborhood that has 100 DSL customers and that is fed by a DS3 (45 Mbps). In the days before a lot of streaming video such a neighborhood probably felt like it had good broadband. The odds against more than a few customers trying to download something really large at exactly the same time meant that there was almost always enough bandwidth for everybody.

But today people want to watch streaming video. Netflix recommends that there be at least a 1.5 Mbps continuous stream available to watch a video. So up to about 30 households in this theoretical neighborhood could watch Netflix at the same time. That math is not quite that linear as I will explain below, but you can see how the math works. The problem is that it’s not hard to imagine that with 100 homes that there would be demand for more than 30 video streams at the same time, particularly when considering that some households want to watch more than one Netflix stream at the same time.

The problems in this theoretical neighborhood are made worse by what is called packet loss. Packet loss occurs when a network tries to download multiple signals at the same time. When that happens some packets are accepted, but some are just lost. Our current web protocols correct this problem by sending out a message from the receiving router asking for the retransmission of missing packets, and they are sent again. As networks get busy the amount of contention and packet loss increases and the percentage of the packets that are sent multiple times increases. And so as networks get busy they grow increasingly less efficient. Where this theoretical neighborhood network can theoretically accommodate 30 Netflix streams, in real life it might actually only handle 20 due to the extra traffic caused by resending lost packets.

This theoretical network has grown over time from being efficient to now being totally inadequate. Customers who were once happy with speeds are now unable to watch Netflix on an average evening. The network will still function great at 4:00 AM when nobody is trying to use it, but during the times when people want use it, it will fail more often than not. The only way to fix this theoretical neighborhood is increase the backbone from 45 Mbps to something much larger. And that requires capital – and we all know that the large telcos are not putting capital into copper neighborhoods.

Cellular companies have been dealing with these growth issues for a number of years now. Cellular networks are seeing annual growth between 60% and 120% per year, meaning that any improvement in the network is quickly eaten up by increased demand. But t’s a much bigger issue to keep upgrading all landline networks. While there are just over 200,000 cell towers in the US there must be several million local broadband backbone connections into neighborhoods. These range from tiny backbones with a few T1s feeding a few homes up to networks with a few hundred people sharing a larger backbone. Upgrading that many networks backbone connection means a huge capital outlay is needed to maintain acceptable levels of service.

Unfortunately my theoretical neighborhood is not really all that theoretical. The big increase in landline broadband demand is now starting to max out the bandwidth utilization in many neighborhoods. The FCC says that there are 34 million people in the country that don’t have adequate broadband today. But with the rate that neighborhood networks are degrading, that number of households with inadequate broadband is growing rapidly – and not get smaller as the FCC is hoping.