Evolution of link bandwidths
During my first lesson for the undergrad networking class, I wanted to provide the students with some historical background of the evolution of link bandwidth. Fortunately, wikipedia provides a very interesting page that lists most of the standards for modems, optical fibers, ...
A first interesting plot is the evolution of the modems that allow to transmit data over the traditional telephone network. The figure below, based on information extracted from http://en.m.wikipedia.org/wiki/List_of_device_bandwidths shows the evolution of the modem technology. The first method to transfer data was the Morse code that appeared in the mid 1800s. After that, it took more than a century to move to the Bell 101 modem that was capable of transmitting data at 110 bits/sec. Slowly, 300 bps and later 1200 bps modems appeared. The late 1980s marked the arrival of faster modems with 9.6 kbps and later 28.8 and 56 kbps. This marked the highest bandwidth that was feasible on a traditional phone line. ISDN appeared in the late 1980s with a bandwidth of 64 kbps on digital lines that was later doubled.
When the telephone network become the bottleneck, telecommunication manufacturers and network operators moved to various types of Digital Subscriber Lines technologies, ADSL being the most widespread. From the early days at 1.5 Mbps downstream to the latests VDSL deployments, bandwidth has increased by almost two order of magnitude. As of this writing, it seems that xDSL technology is reaching its limits and while bandwidth will continue to grow, the rate of improvement will not remain as high as in the past. In parallel, CATV operators have deployed various versions of the DOCSIS standards to provide data services in cable networks. The next step is probably to go to fiber-based solutions, but they cost more than one order of magnitude more than DSL services and can be difficult to deploy in rural areas.
The performance of wireless networks has also significantly improved. As an illustration, and again based on data from http://en.m.wikipedia.org/wiki/List_of_device_bandwidths here is the theoretical maximum bandwidth for the various WiFi standards. From 2 Mbps for 802.11 in 1997, bandwidth increased to 54 Mbps in 2003 for 802.11g and 600 Mbps for 802.11n in 2009.
The datasets used in this post are partial. Suggestions for additional datasets that could be used to provide a more detailed view of the evolution of bandwidth are more than welcome. For optical fiber, an interesting figure appeared in Nature, see http://www.nature.com/nphoton/journal/v7/n5/fig_tab/nphoton.2013.94_F1.html