1, 2, 3, 4, 5G Cellular Communications

by Jan 1, 2018Mobile-Cellular Technology0 comments

I think everyone would agree that cellular or mobile communications has revolutionized the way humans live and interact. I don’t need to tick through the profound changes that have resulted from this sea change, but I think it is instructive for us all to grasp some of the technological underpinnings of this revolution.

Anyone exposed to cellular service marketing has heard the phrase “4G LTE”, but many probably have no idea what that means. This is the most current worldwide cellular standard and is the 4th generation of mobile technology referred to as “Long Term Evolution” or LTE. Why the phrase “Long Term Evolution” was chosen is the subject of some debate, but I think the basic idea is that LTE represents an evolution to a cellular standard that closely aligns with the Internet paradigm: voice, video and data are ultimately all just packets which are asynchronously routed through a network. Compared to previous generations of cellular technology the LTE approach is cheaper, provides higher data rates and is compatible with Internet standards.

To put LTE into perspective, let’s review some history of mobile communications to illustrate how we got to this state and where we are headed. (For the techies out there, I have simplified some of the analysis to make it more relatable.)

1G (1970s, 80s and some of 90s)

The first generation of mobile communication is largely unremarkable from a commercial perspective. These were very limited and expensive analog networks which began in the mid-1970s and were characterized by large brick-like handsets or “bag phones”. Unless you were a Wall Street tycoon or the like, you probably had little or no familiarity with this technology. It simply was not meant for the masses.

2G (1995 – Present)

Cellular communication, as we know it today, started with a 2nd generation digital technology called GSM (Global System for Mobile) communications. The history of GSM actually begins in the 1980s, but commercially viable networks didn’t emerge until around 1995. GSM networks were optimized for voice calls with a short message system (SMS) added on for quick “chat messages”.

There was a competing (totally incompatible with GSM) 2G cellular technology called CDMA (Code Division Multiple Access) introduced by Qualcomm which gained some limited market share, most notably in the US (Verizon and Sprint) and Korea. Though some techies will swear that CDMA was a superior technology it really only served to muddy the waters and GSM was the predominate worldwide 2G cellular technology.

GSM networks still exist today but their prominence is fading—at least in the developed world. AT&T in the United States decommissioned their GSM network on January 1, 2017 and other service providers are beginning the wind-down process as well. GSM technology does not efficiently use precious licensed spectrum and thus providers are freeing up or “refarming” that spectrum to use for their new 4G LTE networks.

3G (2003 – Present)

The 3rd generation standards and service provider deployments feel to me like they were almost lost in history. 3G networks required a complete upgrade of technology and were expensive to deploy but were quickly supplanted by 4G LTE. 3G networks still exist today, but at least in the developed world, they are really just a backup network for when you cannot get on 4G. I let out a small groan (and an occasional curse word) whenever I am forced to use 3G because 4G isn’t available. I consider that to be a poor coverage area for my Verizon service. In fairness, it wasn’t until 3G that one could get a semi-reasonable Internet experience with downloads in the 1 Mbps range as opposed to 100s of Kbps.

For those that care, the predominant 3G technology is called UMTS or Universal Mobile Telecommunications System.

4G (2009 – Present)

4th generation LTE technology is the current state of the art. LTE ushered in the smartphone era as we know it, coinciding roughly with the launch of the Apple iPhone (2007) and first Android phones (2008). With LTE you could reliably get 20 – 30Mbps (or more) download speeds which made your phone Internet surfing and video playback experience—for the first time— on par or better than most home, fixed Internet connections. See a related post on how bad my home Internet connection was until recently.

5G (2020 – ??)

The 5th generation standards are still being developed and first commercial rollouts will likely occur in 2020 or so. I will write about this in a future blog post.