The Crowded Airwaves of California

The Crowded Airwaves of California

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COMMUNICATIONS

To unclog communications, the chiefs of San Mateo County gave up their positions as No. 1 on the radio.

Take technological transformation. Add population explosion. And what you have is a potential communications crisis.

By the mid-1980s, San Mateo County, on California’s coast just south of San Francisco, had been among the nation’s fastest-growing for more than two decades.

Communications technologies were changing even more rapidly.

In mid-1984, 19 fire departments in San Mateo County were using a total of 14 frequencies, mostly on two-channel, tube-type radios. And most had their second channel tuned to one of California’s three statewide Office of Emergency Services mutual aid frequencies, White 1.

With a growing network of mutual aid for statewide sharing of resources to serve the increasingly urbanized communities effectively, as well as automatic aid agreements between bordering communities, fire chiefs were reaching the same conclusion in every municipality: Their radio communications systems, many of which were more than a decade old, were rapidly becoming the weak links in the chain of combined command. Three or four generations of technological sophistication had passed them by. Some of the equipment they used was so outdated, repair and replacement parts were becoming very difficult to obtain.

The 19 communities stretch from San Francisco’s southern border southward to the Palo Alto city line just north of Stanford University. The region extends from the Pacific Ocean on the west to the San Francisco Bay on the east and includes the San Francisco International Airport, operated by the city and county of San Francisco, both of which are 10 to 15 minutes to the north of the airport.

Officially, San Francisco was the first-due department for the airport; in reality, any significant incident at or adjacent to the airport created a need for assistance from the closer departments in surrounding San Mateo County.

By mid-1984, the chiefs recognized they had, in effect, 19 people on one telephone trying to call 18 people somewhere else in the county. When too many conversations after second alarms and during critiques of incidents started with “I could never get them to respond” or “I could never get on the air to tell them we were available,” the chiefs were persuaded to examine their growing frustration with their communications equipment.

They met to draw up a list of difficulties that had become routine, unwanted occurrences. Using that as a starting point, three chiefs, a communications technician, and a representative of a manufacturer of radio communications systems were appointed, with the San Mateo chief as chairman, to acquire technical knowledge, identify the departments’ mutual needs, and define those needs in terms of product design and availability.

The first priority was finding what the departments had in common so it would be possible to develop a communications plan for use by all San Mateo County fire agencies. During two months of study and preparation, committee members reported back to the chiefs after each meeting, to assure them the work would produce acceptable solutions.

The top choice was to integrate the fire frequencies in use in the county into a plan that would allow every department to have and share the same frequencies.

Initially, one of the hurdles was convincing the chiefs themselves. After years of having a great deal of autonomy, their tendency to be protective of their own prerogatives was strong.

To obtain the chiefs’ agreement to accept the plan, each of them had to be convinced that he had far more to gain by giving up the exclusive domain of his local control than by clinging to it any longer. One meeting featuring a flip chart that showed how each department would actually gain the use of several channels was enough to do the job. They were convinced.

Initially, one of the hurdles was convincing the chiefs themselves. After years of autonomy, the tendency to protect one’s own prerogatives was strong.

A new radio protocol that would guide each dispatch center in requesting the use of a mutual aid frequency was the foundation for the new level of cooperation. The need and the willingness to scan 16 channels and share them on a priority basis, rather than on the then-existing “what’s mine is mine” basis, is now the backbone of the plan.

Thought process

We chose 16 channels because committee members wanted enough to handle existing and foreseeable future needs, to allow channels for other local government agencies, and to tie in with all three statewide emergency service mutual aid channels.

Existing needs were defined in terms of integrating four command and five tactical channels: command for the communications between the incident commander and his divisions and between them and their individual sectors, tactical for the unit-to-unit communications.

By the fall of 1984, the committee members proposed and the chiefs subsequently adopted a plan from which they drew specifications to meet those goals and eight specific objectives.

Space for future growth in the number of usable channels was an obvious necessity. In the previous 20 years, for instance, Daly City’s population had virtually doubled; the growth rate is still strong. Other cities in the county—San Mateo, Millbrae, South San Francisco, San Bruno, and Menlo Park— were and still are adding to their populations daily.

Other radio equipment options the chiefs wanted were available at little or no extra cost:

  • Power output with a choice of either 55 watts or 110 watts offers flexibility to cover long distances and to avoid causing interference on a distant system when high power isn’t necessary.
  • Using a built-in switch so radios can have either a positive or negative ground saves the expense of purchasing more costly converters at a later date.
  • The priority channel that’s assigned by the dispatch center can now be selected by either push button or dial, much the way the radio station selector in a car works. In the fire department radios, however, the frequencies— grouped in a 12-megahertz range around 154 megahertz—are specifically programmed into a microchip called a PROM (for programmable, read-only memory). The wide-band coverage was required because California, with nearly 12 percent of the nation’s total population, already has a very low availability of radio frequencies.
  • For similar reasons, committee members recommended use of a private-line squelch to block out interference by unwanted signals from agencies outside the area. That’s accomplished by using what’s known as an automatic, tone-coded squelch.
  • The automatic squelch system also has a shut-off switch, so that in mutual-aid or automatic-aid situations, responding units from other departments can continue to talk with each other despite their differing tone codes.
  • Finally, committee members wanted radios that are repeateradaptive—that is, able to resend a received signal from a mobile unit in a vehicle to a portable unit strapped to the back of an individual firefighter. In rugged canyon and hill terrain, relying on the lineof-sight nature of a groundwave can be hazardous [see “Radio IQ,” page 35].

By the time the committee members had finished our work, we knew that only one supplier could actually meet our technical requirements. The specifications were drawn so that we would get a bid from that manufacturer. Bids also came from two other suppliers, but they didn’t fully meet our needs.

Within six months of the date of the chiefs’ first meeting to appoint a committee, we were ready to make our purchases. Having worked with a communications technician and a manufacturer’s representative from the start, we not only had the opportunity to learn about the latest available technology, but we were also able to obtain competent advice on how to purchase the most for our constrained financial resources—the selector switch for positive or negative grounds versus the more expensive converters.

In phase

As both plan and specifications came into focus, it was also clear that not all of the individual departments would be able to make the transition to the new radio communications technology at the same time.

Now, three years after the specifications were ready, the transition from the old system to the integrated system is still only about 70 percent complete in terms of equipment purchases. Budget constraints and the need for other, even higher-priority purchases mean San Mateo County’s smaller fire departments won’t complete the transition for another 18 to 24 months.

In the meantime, it should be clear that while all the departments are sharing frequencies limited by older radio systems, it’s very difficult for any department to retain its traditional “No. 1” position on the radio dial. As long as each department operated on a different frequency, the old, twochannel radios allowed any department to take channel 1 for itself and assign the second channel to the statewide emergency mutual aid system.

But in the process of coexisting with both an old and a new radio system for several years to accommodate the replacement schedules of 19 separate departments, the attachment to the first position on the radio has had to go.

Firefighters have had little difficulty accepting and adjusting to the change, with the help of a card printed with an index to the changes which has been distributed to the more than 400 individuals who make up the departments. Now as the remaining departments purchase their new equipment, they can adhere to the new order easily.

The transition is working well because we had the opportunity to develop a communications plan that handles our current needs and anticipates the future, to win the active support of all the chiefs, to use professional expertise to acquire the best technology suited to our needs, to phase in equipment as resources become available, and to involve all our firefighters to make it work in every situation.

As one of our people said, “We’ve gone from the Flintstones to the Jetsons in just four years.”

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