Copyright 1998, 2001 Harry Marnell


An Unofficial History of the Los Angeles Police Department's Communications Division

 The Beginning 

On March 28, 1931, under Police Chief Roy E. Steckel (at right), what was probably the most modern and efficient municipal police radio system in the world was completed -- the Los Angeles Police Radio, using the call letters KGPL.

In the beginning, calls were all received by the main City Hall switchboard operators. Those requiring police service were routed by a conveyor belt on top of the switchboard to call dispatchers, who forwarded the information to the radio-transmitting station in Elysian Park. From there, radio dispatchers broadcast the calls to patrol cars using a one-way 500-watt De Forest "A.M." radio transmitter. (Patrol Officers could receive calls, but could not "talk back" to the dispatcher). Two police officers were assigned to handle these calls


Originally, 44 automobiles were equipped with receivers. It was found that officers driving "swift moving automobiles" took an average of only two minutes forty seconds to respond to any call in the city, so thirty-five additional car radios were added as soon as funds became available. The first monthly report in June, 1931 indicated 12,644 radio messages broadcast.

 KGPL on First Day of operation

Desk sergeants and detective offices were equipped with receiving sets, and for important calls, detectives could respond immediately to the scene in their once-famous "fast cars." Soon, radios were installed in sergeants' vehicles, and major calls could be answered by field supervisors as well as by the concerned patrol car. This served as an efficient checking system as well as an added help in case the officers needed any assistance. The two-way system where officers could transmit as well as receive would not come into effect until 1938.

Department broadcasts were heard regularly by the LA Sheriff's Office, the Orange County Sheriff, the police departments of Beverly Hills, Alhambra, Santa Monica, Culver City, San Fernando, Hermosa Beach, Huntington Park, Burbank, Glendale, La Habra, Moorpark, and as far off as San Clemente. LAPD would frequently transmit high-priority calls for those departments' radio-equipped cars.

"Calling all cars, calling all cars..."

It should be remembered that the early 30's were the deepest of the depression years, and people didn't go out much.  And while radios had become very popular, good radio programs had not yet been developed.  Since police broadcasts were just above the broadcast band - LAPD was on 1730 kilocycles (kcs) - most home radios could tune them in.  At night, the signal of LAPD could be heard all across the country, even as far as the east coast and Hawaii. (And listeners could not only hear LAPD, but the then-new CHP had a frequency even lower, and at night, people could hear both departments' calls all over the country).

In these early days of police use of radio, it was customary for a dispatcher to end a call broadcast by giving his last name. One of LAPD's first radio dispatchers in 1931 was Jesse Rosenquist (1899 - 1966). Rosenquist, it seems, became quite famous across the country, because of the way he said his name. He had a deep voice, and he dragged out each syllable, "Rose-n-quist." so people everywhere became familiar with "Calling all cars, calling all cars...that is all. Rose-n-quist."

Before long, it was recognized that the full effectiveness of radio broadcasting required a more streamlined method of call-taking. A new system was instituted, which increased speed in answering and dispatching calls. Now, police officers working the eight position "complaint board" would receive all incoming public calls directly instead of having them relayed by the city hall switchboard. These officers were required to have at least five years experience in the field. Calls were then sent by the conveyor belt to the police radio room, which had five radio positions and a "link" operator. The room had overhead speakers to monitor calls from patrol cars, and status boards consisting of 48 buttons and ticket files.

Following inauguration of the radio-communication system, it was necessary to divide the city into 60 radio-patrol districts, scattered throughout the 15 geographical divisions according to activity of crime. This was also the start of numbering patrol units according to their division of assignment. Then as now, for example, Central Division cars began with the number "1."

An oversized patrol-district map was retained in the central dispatching headquarters, and reduced copies were placed on curtain rollers in each patrol car! Each car on radio patrol duty was equipped with all necessary data so it could be reassigned to a designated district on short notice in emergencies.

 A centralized teletype system and a statewide teletype system were also operating. The Gamewell call-box system was utilized for hourly "call-ins" by officers in the field, as it had been since very early in the century, , and would continue to be used well into the 1970s. At that time the remaining Gamewell-circuit phones were converted to regular dial phones and continue to see occasional use even as we enter the 21st century.

RTOs in City Hall, circa 1950


As mentioned, originally 1730 kilocycles (kc) was the dispatchers' "talk out" frequency. When the two-way system was introduced, the cars called in on frequencies in the 39 mc "VHF" range. In 1948, these "talk-in" frequencies moved up to the 154-155 mc band (there were 7 plus the supersecret "frequency 9" for surveillance). Frequency 9 continues in use today as "Tac 1."

As the city grew in the 1950's, and radio traffic increased, a second frequency of 2366 kc was added for dispatching to the Valley, Harbor and West LA and Venice.

The San Fernando Valley area dispatching was by then being handled from a separate facility in Van Nuys. (Harbor, West L.A. and Venice had, for many years, the dubious distinction of being referred to at Communications as "outlying" divisions...as if they were somehow perceived as different or second-class). In a major restructuring in 1964 and 1965, "talkout" was changed to the 158-159 MHz radio band, and RTOs eventually had five frequencies (A, B, C, D and E) for dispatching to their respective divisions.

RTO at Parker Center, circa 1968


When the new "Police Administration Building" (later renamed "Parker Center") opened in 1955, Communications Division was one of the first facilities to begin operation. Interestingly enough, though the space was more than three times as large as the previous cramped space in the north wing of City Hall, the general operation continued much as it had for many years. It is said that many of the operators' "status boards" were literally carried over from City Hall and installed in the horse-shoe shaped "mike room" consoles. Calls continued to be taken by policemen at the complaint board, and were still sent by a fast conveyor belt into the radio room.

Over the following years, of course, much upgrading and modernization did occur. The old paper-tape teletypes were replaced by continuous-feed paper machines, and those in turn were replaced by computer terminals. Rotary-dial phones were replaced by touch-tone and Centrex switching. The "Gamewell" system - street-corner callboxes connected to manual patch-cord switchboards - was converted into part of the regular city telephone network. More radio channels on more dependable frequencies and equipment were put into service. But the actual dispatching system remained virtually identical to that of the 1930s.


In the late 1960's, under the direction of Chief Tom Reddin, the department embarked on a mission to see if and how "space age" technologies could be put to use in the long-term by LAPD. It had become apparent that the dispatching system was quickly becoming obsolete, and would not be capable of handling expected call volumes in the 1970s and 1980s. Reddin's staff began working with Hughes Aircraft Company to study the existing communications system's efficiency and effectiveness, and developed a conceptual design for updating it. In 1972, under Chief Edward Davis, Jet Propulsion Laboratories performed a detailed analysis of those ideas, found them to be practical and technically feasible, and proposed a phased implementation over a number of years.


The culmination of those far-sighted plans was the "Emergency Command Control Communications System" (ECCCS, pronounced "X"), which consisted of five subsystems:

  • The ECCCS Radio System (in the "UHF-T" band, at 506 & 507 MHz)

  • Mobile Digital Terminals (MDTs)

  • Computer-Aided Dispatching (CAD)

  • Remote Out-of-Vehicle Emergency Radios (ROVERs)

    (the venerable "workhorse" Motorola MX350s in the beginning)

  • Area Command Centers (ACCs) at the 18 local police stations


The first phase was assignment of new voice radio channels to uniformed divisions, starting with Central Bureau in March, 1981, Valley Bureau in December of that year, and South and West Bureaus followed in July of 1982. First used were the popular "old reliable" Motorola MX-350 handheld radios.

It should be remembered that, until that time, the technology and costs associated with portable or "handheld" radios made their widespread use impractical in a city as large as Los Angeles. 


THESE 8-channel repeatered radios Replaced THESE 4-channel "bricks"

Being able to now equip every officer with his own two-way radio was a real milestone for LAPD and officer safety, as described at the time by Chief Daryl Gates:

"ROVER, the Remote Out-of-vehicle Emergency Radio is a two-watt, 8-channel, hand-held radio that can be utilized in two environments, portable and mobile. When used as a portable, the officer will always have communications available. A Request for an Automated Want/Warrant System (AWWS) check, for a supervisor or additional information can be made from locations away from the vehicle. There will be approximately 3,500 ROVERs utilized by field forces to increase officer availability, making it possible to contact an officer away from his vehicle on a non-emergency call and reassign him to one of high priority. To utilize ROVER as a mobile radio, it must be inserted into the Converta-com, located under the dashboard. The Converta-Com automatically connects the portable to a mobile microphone, a high power mobile speaker and an antenna.

"Each ROVER is identified by a four digit number. At the beginning of Watch, the officer will notify the RTO of his unit and the ROVER identification number, i.e., "1A12 with ROVERs 6125 and 6126," by voice or via the MDT.

"The ROVER system also has the ability to communicate from one radio to another without having to switch to a tactical frequency. Normal operations occur in the "duplex" mode, in which messages are sent and received by the dispatch center. In duplex operation, the system is repeated. This means that all officers broadcasting from the field will be rebroadcast on the RTO's frequency, incorporating the "cheater" feature in every ROVER. By switching to "simplex," one officer can talk to other officers on the same frequency without talking to the RTO. The RTO transmission will interrupt or override simplex voice transmission. Only those portables that are in close proximity will receive the transmission made in the simplex mode.

"The ROVER is equipped with a unique capability - the emergency trigger. This trigger enables the officer to request help digitally when circumstances prevent the use of voice transmission. When the trigger is activated, the ROVER automatically switches internally to the emergency channel. The emergency channel is a City-wide frequency utilized for emergency transmissions only. The "help" message is received by the RTO, who will be alerted by a digital and audible alarm on the display console. The RTO must know the unit's last assigned or Code 6 location in order to dispatch help.

"The ROVER will transmit the digital tone once every five seconds for thirty seconds. The digital ID is correlated to the officer's unit and location. The requesting officer's voice transmissions will take priority over the emergency code when the push-to-talk bar is activated. To resume normal operations after the emergency has terminated, the officer simply turns the portable off and then back on.


For digital communication with the Mobile Data Terminals in the police cars, it was decided to use the five former VHF "voice" dispatch frequency pairs, one for each geographic bureau and one for city-wide or back-up use.


MDTs give officers a second means of communication with the dispatch center and with each other. A significant number of messages do not require voice communications, such as routine status changes and database inquiries.

The MDTs have typewriter-like keyboards, computer-like monitors, and 16 "status" and other standard message buttons.

Important MDT capabilities include:

  • The ability to receive calls for service displayed on a screen, thus reducing voice-radio congestion.

  • Direct access to computerized databases to obtain want/warrant, stolen vehicle, DMV and other information without having to go thru the RadioTelephone Operator.

  • Digital messaging from car to car, to the station or to Communications Division, and

  • One-touch "Officer needs Help," officer needs "assistance," and request "back-up" buttons, which signal Communications the unit's identification and last known location.

CDC Opens ... and 9-1-1 arrives

The computer-assisted dispatch system went online in the new "Central Dispatch Center," four stories below City Hall East, at 4:00 a.m. on Sunday April 17, 1983. Dispatching for the five patrol areas of the Valley Bureau was transferred from their former "mike room" in Van Nuys. After a 6-month shake-down period, the three remaining bureaus went online in October.

Three months later, in January of 1984, the 9-1-1 emergency number became operational throughout the City of Los Angeles. In nine short (but well-planned for) months, LAPD's communications system had undergone a complete make-over.

The CDC is equipped with 62 consoles and terminals, including:
  • 55 CDC Operator consoles: Each CDC Operator has two display screens, a keyboard, a radio-control panel, a headset, a telephone keyset, and an instant-playback recorder. Four of these consoles are also designated as "Alarm Positions" and are equipped with special 60-button keysets connected to alarm lines.

Operators ("Police Service Representatives") are assigned daily to either a radio-dispatching position, a 9-1-1 phone position or another auxiliary telephone assignment.


4 Bureau Communications Coordinator consoles: The "BCCs" are supervisory operators, who also perform additional duties, such as using extra voice radio frequencies when needed, inputting additional computer commands, and monitoring the telephone system operation.

System Monitor Operator
  • 1 System Monitor Operator Console: This console has hardware ID displays for all ROVER frequencies, and computer status and reconfiguration capabilities. The "SMO" makes sure the whole system keeps running.

  • 1 Data Service Bureau System Operator terminal

  • 1 Communications Division Watch Commander terminal

Radio Control Panel - Rows of lights at top show the status of radio frequencies

Several thousand police officers had to learn how to use the MDT's too. A Police Academy training session.


Here's what the future has in store for LAPD Communications

When the CDC opened in 1983, it embodied the future of law enforcement communications in Los Angeles. However, within a year of the center's opening, the call-volume had surpassed estimates for the 1990s. Currently approximately 6000 emergency calls and 8000 non-emergency calls are received daily, and about 5500 of these are dispatched to police units.

This has caused a number of problems, mainly because of the lack of room to expand. Over 600 employees are assigned to Communications Division. Dispatching is handled by civilian Police Service Representatives (PSRs), with as many as 90 people on the dispatch floor at any given time, including supervisors and trainees.

A 1992 bond issue to revamp communications once again is about to come to fruition. Expected to cost a total of $250 million, two new "state-of-the-art" dispatch centers are nearing completion - one at 1st and Los Angeles Streets, next to Parker Center Police Headquarters, and the other 23001 Roscoe Blvd in Canoga Park.

The downtown "Metropolitan Communications Dispatch Center" will generally handle the nine patrol areas and two traffic divisions in Central and South Bureaus, while the "Valley Communications Dispatch Center" will handle calls for the nine patrol areas and two traffic divisions in the West and Valley Bureaus. The two centers will at all times be connected with each other in real-time by fiber-optic and microwave networks; in the event of a disaster, equipment failure or problem at either center, the other will be able to absorb some or all of the workload almost instantly.


A completely new radio "backbone" system is being constructed, with a 109-channel UHF and VHF frequency plan, operable in either analog or digital mode, with advanced encryption (scrambling) available as well. All existing mobile and portable radios are in the process of being replaced with new equipment, and one of the department's priorities is to acquire handheld portable data terminals first for all motorcycle officers, and then for foot and bicycle patrol officers.

Astro Saber III Portable Radio
LAPD Contract Announcement---Radio Specs


About 1200 new Motorola MW-520 vehicle MDTs have already been installed, and when the new system is completed in 2002 all 1400 patrol vehicles will be so equipped. The new data system has already been accepted and is in use, with twice as many channel pairs as before, and data speeds approximately eight times faster than the old system.


MW-520 Mobile Digital Terminal

TRW is the primary contractor for system design and integration, and Motorola is the radio system provider. While the voice radio system will be APCO "Project 25" compliant, LAPD has specifically rejected the idea of using radio frequency trunking, which essentially involves computer-controlled frequency "hopping." The idea is to make L.A.'s system as compatible as possible with other agency systems within Los Angeles County and Southern California. Trunking reduces interagency communication capabilities, since all agencies utilizing trunked radio communications have to be incorporated into the master trunking plan. In addition, trunking would add yet another layer of complication to the already complex system.

Construction of the Dispatch Centers is expected to be complete in 2001, and both should be furnished, staffed and operating by the end of 2002.


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