Wireless Tectonics

There are two large technological land masses that dominate the lithosphere of wireless personal communications. Land Mobile Radio is the stable and slowly evolving workhorse of Public Safety, and many residents of that wireless continent are barely able to perceive any movement or change in the terrain. In sharp contrast, 3G Wireless is the hyper-volcanic and rapidly advancing mainland that is shaking the planet, and occasional meteor strikes re-shape its landscape overnight (think Apple iPhone).

 

And while it may have appeared that these two technologies were peacefully coexisting, LMR dominating Public Safety and 3G dominating the mass markets, we can now see that within the Public Safety arena they are actually colliding. The unfolding of that collision is not widely followed outside of the Public Safety industry, but it is a most interesting story to follow, especially if you are a follower of the strategies of all things wireless.

 

Continuing the metaphor for a moment, I’ll enumerate some of the contrasts that comprise the “fault-line” between these two technologies:

 

LMR networks support Push-to-Talk (PTT), which is half-duplex, group-based, voice communications.	3G networks support group based PTT, as well as 1-to-1 PTT and full-duplex voice
Most LMR radios will not operate outside of their home network	Most 3G devices roam successfully beyond their home network
LMR radios are expensive, often costing a few thousand dollars per unit	Most 3G devices are available for less than a few hundred dollars
The prospects for streaming video to an LMR radio anytime in the near future is not good	There are at least 3 video streaming services for 3G devices available today (MobiTV, VCast, MediaFLO)
LMR radios require auxiliary equipment to provide a GPS location	Most 3G devices have integrated GPS capabilities and also support Assisted GPS so that indoor location fixes are possible

 

3G looks very favorable, but as there are two sides to every coin so there are some very good reasons that a firefighter running into a burning building carries an LMR portable unit rather than an iPhone. Here’s some advantages for LMR:

–          Demonstrated ruggedness – confidence that the radio will operate regardless of how it is treated.

–          Even handhelds have big batteries and 3 watts of power

–          Spectrum bands that propagate farther and penetrate better than most cellular bands, especially PCS

–          Base stations are equipped with backup power

–          Simplicity of design, at least for conventional LMR: when you press the Talk button you get to talk, period. No arbitration by a computer about who gets to talk. If two people are talking at the same time then the one yelling the loudest will be heard the best. That’s what I would want if I were suddenly being fired at by the driver I just pulled over for running a stop sign.

 

In short, an LMR network is designed to be a life-critical communications tool that is exclusive to the government or enterprise organization that owns it, while a 3G network is designed to provide ubiquitous, profitable advanced services for the mass market.

 

These “continents” don’t converge very nicely. Or do they? I propose that this convergence will proceed incrementally, without major “earthquakes” as 3G enters the Public Safety domain, and with great benefits to Public Safety organizations. Convergence may be the wrong term however, because for the foreseeable future I believe that both network technologies will continue to exist independently. What will be different is the relative roles of LMR and 3G in Public Safety communications.

 

In Public Safety today, LMR dominates while 3G augments LMR and provides some data capabilities at better cost and performance than LMR can. For example many police vehicles are equipped with laptop computers that are wirelessly connected using 3G aircards.

 

But the domination and augmentation roles will gradually reverse. Eventually, 3G networks will become the dominant solution for Public Safety voice, video, data, and location based services, and LMR will augment 3G by providing life-critical communications to specific types of front-line first responders.  Two large steps towards this future are about to occur:

1. The interoperation of PTT voice between commercial 3G networks and private LMR networks. With this capability the Public Safety PTT talkgroups will begin consisting of a hybrid user base – some carrying radios and others carrying cellphones. Regardless of the device type, when a member of the group presses the talk button and speaks all of the group members will hear it. Once this capability achieves moderate deployment the role-reversal will begin in earnest; personnel that once were loathe to part with their radio will find themselves seduced by the capabilities offered by the cellphone.
2. The 700 MHz D Block  auction will complete sometime in 2009. Even though the networks built for this spectrum must give special priority to Public Safety users none of them will be built out with LMR gear. The D Block will be deployed with some mix of 3G and 4G technology, or perhaps 4G exclusively.

 

Both of these advancements were recently tested by the US Department of Homeland Security, in a pilot called Radio Over Wireless-Broadband (ROW-B).

 

As this role reversal proceeds the market is adjusting and beginning to incorporate other LMR-style capabilities into 3G networks, for example:

–        PTT will become more capable and widely deployed on 3G (VzW  & Sprint ).

–        More rugged devices will become available (see Sonim , Casio )

–        Backup power for base stations will arrive sooner rather than later

 

The next several years will see some dramatic shifts for residents of the Public Safety continent as the 3G world encroaches. LMR will continue to provide a steady hand-hold as the convergence proceeds, but the landscape of new capabilities that regularly arrive will remind all that this is a new world.