View from the Top

Digital is the future, like it or not


Mark CrosbyRepresentatives from the Land Mobile Communications Council ( and several FCC bureaus — wireless telecommunications, public safety and homeland security, and enforcement — met recently to discuss issues associated with the growth and popularity of digital communications systems. The good news is that digital systems are very spectrum efficient, provide connectivity to other digital-based communication networks, and offer an ever-growing array of features that both business/industrial/transportation (BILT) and public-safety entities demand to better serve their respective missions.

Indeed, digital-based communication systems in the land mobile bands — from 150-900 MHz, as it was noted during the FCC meeting — will soon, very soon, represent the majority of these systems. If there is unpleasant news associated with the growth of digital systems, it is the fact that digital and analog technologies don't always play together well in the shared 150-470 MHz BILT and public-safety bands.

This is, of course, where the BILT and the public-safety organizations part ways, from a strategic standpoint, regarding how best to manage and accommodate customer preferences for digital technology. Now before I risk upsetting any of my public-safety friends, including the thousands of such entities that EWA serves each year, I fully recognize that there are segments of this industry that have special requirements that are better served through analog devices and system capabilities.

No one is suggesting, not even remotely, that those capabilities are not important to public safety and are best left alone. But if I were asked by a BILT licensee who was about to totally upgrade a communications system whether they should choose an analog or a digital system, all things being equal, I would not hesitate to suggest that they should choose digital.  And if an EWA public-safety customer were to ask me the same question, I would give the same answer.

But until almost everyone is operating a digital system and spectrum-sharing therefore becomes more compatible, certified frequency-advisory committees, vendors and applicants may need to do a deeper dive into the technology in order to ensure that its benefits are fully realized. This might include more-collaborative discussions to identify optimum channels within digital trunked systems when some of the channels are not exclusive and, therefore, subject to the regular monitoring requirement.

There is no reason why, as a matter of course, applicants cannot be provided a list of users with whom they could be sharing channels and the technologies that already are in use on them.  This is a practice that EWA follows in many instances in BILT spectrum-starved geographies. For example, selecting the optimum frequencies, say in Los Angeles County, for a 10-channel trunked system is not for the faint of heart.  You have to work together to manage expectations. Educating applicants on monitoring requirements, techniques and other operational best practices also will go a long way toward mitigating potential sharing issues among digital and analog licensees.

Maybe EWA could start informing incumbent operators that a new co-channel system has just been authorized in their service area.  Maybe! I need to think, for a minute or two, about possible unintended consequences of that approach.

In the BILT world, we should absolutely pursue these technology enhancements as we have no realistic alternatives.  We are not blessed with an abundance of spectrum choices (to put it kindly). We simply do not have the luxury to implement a "go or no go" frequency-coordination scenario. We must support the advancement of digital technology — all digital technologies, no matter what the emission designator. Narrowbanding has provided needed additional capacity, perhaps not 2-for-1 capacity, but additional spectrum capacity nevertheless. The transition to digital is as welcome.

At one point in the LMCC-FCC meeting, one of the more-notable public-safety spokespersons defended an engineering-based frequency-coordination solution for the public safety VHF band by stating that "our spectrum isn't used to fix leaky pipes, but to address man-down emergencies and we cannot afford any interference whatsoever."  Leaky-pipe fixers?  Really? Can you imagine the offense that rightfully would have been taken by the public-safety attendees had a BILT attendee questioned public-safety spectrum use?  And since most of us ride on trains from time to time — even public-safety personnel — we'd best hope that the communications needed to operate a railroad safely aren't delayed or garbled — to say nothing of nuclear power plants.

We may find that there just isn't a lot of commonality between BILT and public-safety approaches on how to best accommodate digital systems.  But both parts of this land mobile community need to permit a reasonable transition for digital technology, because its future is now.

What do you think? Tell us in the comment box below.

Mark Crosby is the President/CEO of the Enterprise Wireless Alliance (EWA).

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