Explaining Bandwidth

It is not uncommon for someone to look at me sideways like I’m talking geek.  This commonly occurs when I’m trying to explain bandwidth to someone.  Even if they “hear” the numbers in mbps (megabytes per second), I know they still don’t get the relative jumps of each.  So I’ve created this graphic.

I’ve taken each of the common connective technologies and depicted the throughput as the area of a circle.  Now imaging that each of these technologies is a water (or beer) pipe.  They’ll all eventually fill your glass but how fast do you want that drink to be ready?

Telecom Speeds, click to view

The red colors represent the basic wireline services.  Dial-up modems at 56 kbps; residential DSL at 256 kbps; T-1 at 1.5 mbps; and T-3 at 45 mbps.  Obviously, a T-1 circuit is a far cry from dial-up.
The satellite system at the office runs slightly better than a DSL connection.  Some of the reasons that I push hard to move to a T1 circuit are the more stable connection (not prone to atmospheric influence), a faster connection (so more devices can be put on it), and it reduces the load on the satellite system so more bandwidth is available for use elsewhere on the network.  Even satellite bandwidth is a finite resource and when we are really busy my choke point is not at the remote unit in the field but at the downlink.

The blue colors represent the Wifi standards.  802.11b at 11 mbps; 802.11g at 22-54 mbps; 802.11n at 150-600 mbps.  The technology doesn’t operate at a fixed speed and can vary so I took a figure somewhere in the middle that is most likely.  Now you can easily visualize why upgrading from an 802.11b to 802.11n wireless access point won’t help your internet speed when your home is still on basic DSL.  Although it will help your home network if you move files from one computer to another – like sharing a music library or playing games.  In disasters, we’ve moved to 802.11n on the new wireless access points because we’re seeing a lot of file sharing and shared databases on the local network.  While this doesn’t fill up our bandwidth to the site, it does impact the local network.

The green colors represent the cellular industry.  It needs to be noted up front that these speeds are highly variable depending on devices, distance to cell towers, interference, and signal quality.  EDGE (GSM) at 0.5-1.6 mbps; EVDO Rev A at 1.8-3.1 mbps; LTE (3GPP) at 75-300 mbps; HSPA+ (3GPP) at 672 mbps; and LTE Advanced (4G) at 300-1,000 mbps.  In the right conditions, that EVDO cellular air card in your laptop has a better speed than a T-1 circuit.  Now imagine what is possible when you have a cellular air card running on LTE Advanced.  Expect to see in the next few years a shift from the mentality of one cellular aircard to a computer, to one cellular data connection meeting the data needs of an entire site.

What do you think?  Can this be improved?  How do techies like us communicate this information to our non-technical customers that rely on us yet still want to be better informed?