LASD "Sheriff's Communication Center" Radio Procedures

[finaldraft151]

Hey Everyone;

This is a pretty cool breakdown and accurate explanation of LASD's Radio System and Procedures; There are old threads buried on here that have explained it before, but I came across this and wanted to share; It was obviously drafted a few years ago (Lennox is now South LA Station) but it is still informative and will probably clear up the FAQs when it comes to scanning LASD like: ..."What is up with those 'beeps' on the dispatch channels? OR: .."I live in Norwalk and monitor Dispatch 13, but why am I hearing Lancaster and Lost Hills calls and radio traffic on Dispatch 13?" ...

Hope this helps! Feel free to ask any questions.

Best,

-Eric

LOS ANGELES COUNTY SHERIFF’S DEPARTMENT
RADIO PROCEDURES


How SCC Works
On any given shift, there are anywhere between 8-12 (12 is very unusual) dispatchers working. Of those dispatchers, 2 will be on a break, and one will be assigned to answer alarm company calls. Therefore, it is safe to say that there are between 5 and 9 dispatchers actually working the air every hour (there may be more, it depends on the break schedule).

Contrary to what most Deputies think, each dispatcher does not work only one station the whole night. The system is completely random. A dispatcher is able to have up to 8 channels at one time, and the computer assigns channels to the least busy dispatcher. When a dispatcher is done with a channel, he/she can drop it. Wait, let’s back track for a moment...

Each station in the county has a specific frequency, and that frequency is assigned a dispatch channel number. For example, Lennox/Marina has a dispatch number of 12. Century is 4, Santa Clarita is 5, and so on. It is important for you to know your station’s dispatch number. Also be aware that your dispatch channel is referred to as your home channel/frequency. For instance, if you are on L-TAC with your partners working a 211 in Century, and it goes C/4, someone might say “I’ll go ahead and put it out over 4.” Or you might hear SCC ask for someone to switch back to their home channel.

Now that you know what a channel is, you need to know how a channel is assigned. There are 3 ways, and until one of these things happens, the channel is in effect “floating” around in space. The first way that a channel can be assigned is by a call being sent out. When the station gets a call for service, they type in the call, assign units to handle and assist, and then send it out either digital, or voiced. Digital means the call only goes to MDTs, and is not voiced (read over the air by SCC). Voiced means that SCC reads the call over the air, and the call is sent to the MDT. So, when a call comes out, the channel gets assigned to the least busy dispatcher (the channel pops up onto his/her screen, along with the call).

The second way that a channel can be assigned is by a unit keying up the mike. This is why it is important to key your mike once before talking. If your channel is not assigned, and you begin to talk, when your channel gets assigned you may be talking over someone else. For example, a dispatcher might have Santa Clarita, Norwalk, and Temple. You are from Lakewood, and your channel is unassigned. Therefore, you do not hear air traffic or a busy tone, and you think it is ok to start talking. Meanwhile, the dispatcher is putting out a backup request in Norwalk, and all of a sudden you start talking over it. If you would have keyed your mike once, and waited, you would have heard the dispatcher talking and known that the air was not clear. If you are hearing SCC or a busy tone, then your channel is assigned. Wait for other traffic to stop, and then go ahead. You only need to key your mike when you have not heard anything for a while. If when you key up you still don’t hear anything, then it means the channel is probably clear. If you are ever unsure, just ask: “Is the channel clear?”


The third way that a channel can be assigned is by a dispatcher manually “picking it up.” A dispatcher can self assign a channel to his/her console. This might be necessary when a dispatcher’s console partner has an emergency and needs his/her channels picked up, etc..


A dispatcher will hold a channel for as long as necessary, and then drop it (thereby sending it back to “float” around in space). Things that make it necessary to hold a channel are officer safety issues such as back up requests, code-3 rolls, and any emergency like an assistance request. Other examples are calls such as 211's, 273.5's, and 459's.




What is the Patch?
Normal radio operation is called “simplex”. This means that when a Deputy in the field transmits on a channel, his/her traffic is heard by SCC only (however, the radio within that channel’s station will also receive his/her traffic. This is so the desk can be aware of all traffic as it happens). All other field Deputies, whether from the same station or not, will hear a busy tone. When the “duplex patch” is activated, it “patches” channels together, and changes the frequency from simplex to duplex. This means that Deputies can now transmit directly to one another. No busy tones will exist. This also means that whatever channels the SCC dispatcher might have at that moment, they are all tied together. For example, if the dispatcher has Lennox, Century, and Norwalk when the patch is activated, those three stations have direct communication with each other. If someone from Lennox transmits, Lennox, Century, and Norwalk deputies/stations will hear all traffic.



When to use the Patch
• emergency situations such as pursuits, code 9, etc.
• putting out broadcasts (crime/missing persons).
• coordination of “hot” calls (211N, 273.5N, etc.)

How to request the Patch
4. Emergency: “10-33!, Give me the Patch!” (It is also acceptable to say “give me the patch.”) Just saying 10-33 does not guarantee activation of the patch. 10-33 only means “I need to talk right now, give me clearance.” For example, if you were detaining a 921 at gunpoint, most likely you would say “10-33", the dispatcher would say “10-33" go, and you would talk. Every one else hears a busy tone while you talk.

There are only certain emergencies that automatically receive the patch, regardless of whether or not you asked for it. These are: 1) Foot Pursuits, 2) Pursuits, and 3)Code-9s. If you say, “10-33, I’m in foot pursuit of a 245 suspect...” SCC automatically activates the Patch as you are talking. (But, it does not hurt to ask for it anyway)

5. For Crime Broadcasts: “Century 212A, 10-34 for a 211 broadcast.”


6. For 920C Broadcast: “Century 212A, 10-34 for a 920C broadcast.”

7. For Call Coordination: “212A can I have the patch re my 211?” ; “SCC, can I have the patch re coordination?”



VERBAL FORMATS: what you say, and what SCC says back.

Crime Broadcasts

You: Century 212A , 10-34 for a 211 broadcast.

SCC: Century units and station, stand by for the following 211 broadcast.
212A you’re on the patch, go ahead.

You: 212A advising a 211 occurred 10 ago from 1234 Main St, cross of First, at Maria’s Liquor. Suspect is described as a male white, approximately 27 years old, black over blue, 6 foot, 210lbs. He was last seen wearing a black t-shirt, blue jeans, and black work boots. Suspect was last seen running northbound from the location towards First St, and out of view. Weapon used was a black 9mm handgun. Obtained was $400 in misc US currency. If there are no questions, you can drop the patch.

SCC: Any questions? (Pause) Any questions or information, contact 212A or Century station, patch and channel clear, 2230 hrs.


920C Broadcasts

You: Century 212A, 10-34 for a 920C Broadcast.

SCC: Century units and station, stand by for the following 920C broadcast.
212A you’re on the patch, go ahead.

You: Century 212A advising of a 920C from 1234 Jabber St. in LA. Missing person is Darla Clark, F/W, blk over brown, 4'6", 98 pounds, D.O.B. of 02-25-90. Missing person was last seen at 1300 hrs today, wearing a pink short sleeve top, blue jeans, and pink sandals. She was en route to Cherry Creek Park for soccer practice, and never showed up. If I could have units 927C the area of the park, and if there are no questions, SCC you can drop the patch.

SCC: Any questions? (Pause) Any questions or information, contact 212A or Century station, patch and channel clear, 1452 hrs.


CODE 4s

(Example 1)
You: Century 215 advising its C/4 re the 211S on 212th Street, accidental activation only. 215 ?

SCC: Century units and station, 215 is advising C/4 re the 211S on 212th street, accidental activation only, its C/4.

(Example 2)
You: Century 215 advising its C/4 re the 273.5N, 12233 Stimson Av., 10-15 with one. 215?


SCC: Century units and station, 215 is advising its C/4 re the 273.5N, 12233 Stimson Av, 10-15 with one, its C/4.

Etc....

What is L-TAC?


Each station has an L-TAC, though some share with others. It is a channel, other than the home channel, that is used for direct communication between Deputies. There are no busy tones, and SCC does not monitor the channel on a regular basis. You would use this channel to coordinate with your partners. It is also what you talk on when you are working a non emergent call, like a 459A, etc. Also, some emergencies will end up on L-TAC once things have cooled down (ex. foot pursuit goes to a containment)

requesting a unit to L-TAC (make this request over the home channel)

You: 10-31 46T2.

SCC: 46T2 to L-TAC, 46T2 frequency L-TAC.

*10-31 is generic for “switch this unit to L-TAC”. There are other tactical frequencies (C-TAC, A-TAC), and for these you would say “10-31 46T2 to C-TAC” or “46T2 to C-TAC.”

 

[jrholm]

Eric, this is going in the briefing book at work

 

[zerg901]

Can someone confirm that the 911 calltakers are at the Sheriffs stations scattered around the county, but all of the radio operators are at the SCC (? in East Los Angeles). I cant think of any other agency that operates a system like that.

 

[JoeyC]

I have always found the LASD very interesting to listen to since when I was a kid and heard it on skip on the east coast with somewhat regularity. It is a unique system and it intrigues me when I compare it to what I know as a typical simplex or duplex or repeatered radio operations and how it all seems to work when it is so foreign to what I am used to.

This was a great tutorial (thanks for posting it) and it gives great insight into a system that I've only sporatically listened to over the years. Recently I found that if I park right on the ocean, I can hear most LASD stations crystal clear from here in San Diego. I sat out there the other night and listened for 90 min or so and actually paid attention and tried to follow and make sense of it all.

What I don't understand still however, is when you mention how a channel is assigned and the idea that the channel is otherwise "floating in space". Do you mean the individual dispatchers console floats in space without a specific frequency to work because they haven't got radio traffic and it sits in "available" status until one of your 3 scenarios come up?

Also, I am confused about the keying up first before transmitting. I read the paragraph several times and it isn't clicking. If I am a deputy in lets say Santa Clarita and I have my radio set to ch 5 it monitors 482.8625 I assume and thats my home channel. Then when I key up on 485.8625 (Disp 5-input) I am not understanding why I would have to key up first, release and then start talking on a second key up if there was not already traffic on the air. You stated that if I were to just start talking I might talk right over an already in progress transmission. Why wouldn't I hear that (if it were the dispatcher) or the busy tone (if it were another deputy) without having to "wake up" my radio first with a keyup? Does that happen because all the available dispatchers are occupied and handling traffic on other channels and a free one is not available to handle my call when I key up the first time?

 

[K6CDO]

Can someone confirm that the 911 calltakers are at the Sheriffs stations scattered around the county, but all of the radio operators are at the SCC (? in East Los Angeles). I cant think of any other agency that operates a system like that.

Yes, the call takers are at the stations, and calls are routed to SCC for voicing by their staff.

 

[finaldraft151]

@ JRHolm

Sounds Good!

..Actually, if you want, send me your email address in a PM and I'll forward you the entire file. It has more radio info and instructions on verbal formats and procedure.

 

[finaldraft151]

Can someone confirm that the 911 calltakers are at the Sheriffs stations scattered around the county, but all of the radio operators are at the SCC (? in East Los Angeles). I cant think of any other agency that operates a system like that.

Yes, each station has their own individual call takers that handle the normal business lines and 911. They may be either Sworn or Civilian (although each station might have their own 'policy' as to whether or not they will utilize a Civilian to handle station level dispatching responsibilities) - The person(s) manning the phone lines is working a position referred to as "complaint" or "comp desk" - When a resident calls 911 or a station's business line and requests a call for service, the person working the "complaint" desk will enter a call for service into the department's CAD system. (assuming the call for service requires an LASD response; Not every call will require a police response, but LASD will be the first to answer the 911 line, evaluate the nature of the incident and then take the necessary steps based upon the information from the caller)

For incidents that wouldn't (normally) require a police response, the call taker will transfer the caller to the appropriate agency. A good example would be if someone called 911 for a medical emergency, the call would be answered at the station and then the person working phones would immediately transfer the call to the fire department's centralized dispatch center. (located in East LA at LA County Fire Department Headquarters)

For calls that need and/or require a police response the call taker will then type in the information or a 'narrative' along with the appropriate radio code(s) where it is entered into the CAD system and sent to the station level dispatcher (referred to as "the desk" - or by call sign)

Each station's desk or "dispatcher" utilizes it's station number followed by a Zero and a "D" or "David" - Example: San Dimas is station # 8; They use 80-89 series call signs, so their desk is "80-David" - Compton is station # 28, they use 280-289 series call signs, so their desk would be "280-David" ... The desk utilizes it's station's L-Tac channel to communicate with their field units.

The desk then looks at the call and will assign the appropriate unit(s) based upon the location and/or nature of the call. A call can either be labeled "Routine" "Priority" or "Emergent" and the call taker and/or desk will determine the nature of category, assign units and choose a routing method. Most non emergency calls for service will be routed directly to a unit(s) MDT or MDC and are not voiced by SCC. While any call can be sent out via MDT and to SCC for voicing, most routine calls are not sent to SCC for voicing simply because the amount of call volume would generally exceed the amount of air time available on a station's home dispatch channel.

There are many exceptions and factors that determine how a call is routed, but generally, all priority calls are sent simultaneously to SCC for voicing and to the respected unit(s) MDT/MDC via the station dispatcher.

Emergency or "Code 3" calls are automatically sent to SCC (bypassing the station level dispatcher) so that a dispatcher at SCC can voice the call on the dispatch channel and solicit for units with the shortest ETA to respond. SCC and the station's dispatcher will then talk to one another via a hotline (basically just an intercom) and determine how many units are needed and which ones that are authorized to roll code 3.

This is just a basic generic example and primarily depicts the sequence of events when someone dials 911 from a land line. Cell phones are still 'iffy' - One might dial 911 from a cell phone and be connected with CHP dispatch or depending upon the callers location, be connected to the appropriate Sheriff's Station or agency based upon the callers geographical location; It all depends. Cell phones used to be a nightmare, as one could only see the general area or tower that the caller was 'hitting' - But technology has allowed a 911 operator to pretty much pinpoint a caller's location.

All of this would probably lead one to ask "so why SCC?" - Why not just eliminate the middleman and simplify the process by keeping everything confined at a station level? Good question. LASD is unique when it comes to their radio system and methods. And the method to the madness actually works. Each station can focus solely on their units and calls, while SCC is the nerve center that handles the entire network of stations from one point, thus linking a vast assortment of resources together and having a broader arsenal of communication tools from one site.

It might sound illogical, but with this system, fewer people are actually needed to complete one task. One person at SCC can simultaneously voice a code 3 call, communicate with a station, go out for an aero unit, get CHP and run a plate, while a person at the station level is limited by a lack of available resources to be able to do this all in one shot. SCC gives one person the ability to simultaneously kill 5 birds with 1 stone, which in turn enables individual station personnel to focus on other tasks without ever removing them from the communications loop.

 

[finaldraft151]

I have always found the LASD very interesting to listen to since when I was a kid and heard it on skip on the east coast with somewhat regularity. It is a unique system and it intrigues me when I compare it to what I know as a typical simplex or duplex or repeatered radio operations and how it all seems to work when it is so foreign to what I am used to.

This was a great tutorial (thanks for posting it) and it gives great insight into a system that I've only sporatically listened to over the years. Recently I found that if I park right on the ocean, I can hear most LASD stations crystal clear from here in San Diego. I sat out there the other night and listened for 90 min or so and actually paid attention and tried to follow and make sense of it all.

What I don't understand still however, is when you mention how a channel is assigned and the idea that the channel is otherwise "floating in space". Do you mean the individual dispatchers console floats in space without a specific frequency to work because they haven't got radio traffic and it sits in "available" status until one of your 3 scenarios come up?

Also, I am confused about the keying up first before transmitting. I read the paragraph several times and it isn't clicking. If I am a deputy in lets say Santa Clarita and I have my radio set to ch 5 it monitors 482.8625 I assume and thats my home channel. Then when I key up on 485.8625 (Disp 5-input) I am not understanding why I would have to key up first, release and then start talking on a second key up if there was not already traffic on the air. You stated that if I were to just start talking I might talk right over an already in progress transmission. Why wouldn't I hear that (if it were the dispatcher) or the busy tone (if it were another deputy) without having to "wake up" my radio first with a keyup? Does that happen because all the available dispatchers are occupied and handling traffic on other channels and a free one is not available to handle my call when I key up the first time?

Thanks for your interest and questions!

When one refers to a channel as 'floating' it means that channel is (currently) not 'assigned' to anyone's console; There are several reasons as to why it might not be assigned, but usually it's because there is no active "hold-able" calls for that station, no field personnel are currently running plates/people on their MDT's or simply because nobody is talking. A channel doesn't have to be 'active' for one to hold it. A dispatcher could have Lomita/Avalon's (Dispatch 7) channel on their console along with Norwalk and Compton and never hear a peep from a Lomita or Avalon unit, yet everyone working Lomita/Avalon or anyone tuned in to that channel on a scanner will hear all the radio traffic for Compton and Norwalk. Now say that dispatcher drops Lomita's channel; With no traffic or calls Lomita's channel will float until either Lomita sends a call, a Lomita unit runs a plate or person with a 'hit' on it, or someone simply keys their mic on Lomita's channel. The second one of these scenarios happen Lomita will then land on a dispatcher's console and is no longer "floating" unassigned.

Where it lands is determined by a random computerized "point" system calculated by the number of dispatchers currently plugged in and "live" - Workload determines how the points are calculated, so a dispatcher who is slammed with calls and traffic will have more points then a dispatcher who hasn't voiced as many calls or requests. The dispatcher with the least amount of points gets the 'next' channel.

Since you used Santa Clarita as an example, I'll stick to Santa Clarita for you in this scenario; Let's say you're working a Santa Clarita car. The radio has been jumping all night and after awhile you notice that the radio traffic has pretty much gone silent. At this point there is no way for you (or anyone on the other end of the radio) to know if the silence is a result of simply no radio traffic at the moment, or if your channel is silent because it has been dropped and is now "floating" unassigned. You want to run a plate over the air but are unsure if the channel is silent because it's floating or simply because there is nothing going on. That's where the quick "keying of the mic" comes into play to determine if your channel is "floating" or simply sitting on a console with no radio traffic.

By quickly keying the mic once you accomplish several things simultaneously: If Santa Clarita's dispatch channel was currently floating 'unassigned' to any dispatcher, by simply keying your mic you directed the channel to land on a dispatcher's console. Where it lands is determined by computer so your channel might land on a dispatcher currently holding Lancaster, Lakewood and Temple's dispatch channels. If the dispatcher is currently voicing radio traffic or receiving traffic you will then hear either the dispatcher talking or a busy tone indicating the channel is in use. That's the reasoning behind the "quick key" - If you hear traffic or a busy tone, you would hold off on your radio traffic (unless it was emergency traffic of course) until there is a break in the traffic.

In this scenario if you just keyed your mic and went with your traffic you might land on a console with radio traffic already in progress and then you will cover the other units. But by doing a quick one keying of the mic you will assign the channel to a dispatcher (assuming your channel is floating) and you can determine if the channels are clear.

Again, there is no way for field personnel to know if their channel is floating or assigned, so radio silence could just mean that there isn't anything going on. Tuesdays at 3am are a good example. I could be holding Santa Clarita for 2 hours straight and not get one call or bit of traffic. You do a quick key, and you don't hear a dispatcher talking or a busy tone, go with your traffic. It's not a fail proof system. Channels are dropped and assigned all the time, and the "quick key" is not mandatory each time you need to put out traffic, but more for when you haven't heard any traffic recently and are unsure if your channel is floating.

Ultimately, it's a tool to use and is considered part of radio "etiquette" - But field personnel usually have so much going on that understandably there will be times when units step on each other. (Hopefully) most, if not all dispatchers should know that a field unit is exposed to all kinds of background noise at any given time (sirens, traffic noise, wind, other radios, irate folks, hysterical people, etc) so we understand that with so many other audible and visual distractions, a unit may not have noticed that the channel has gone quiet and in some cases they can't hear the busy tone. I loathe rude dispatchers that chastise units when they accidentally step on other units. It happens. We just have to then determine if any of the multiple units transmitting had emergency traffic and then go from there. I hope this helped answer your questions. I apologize for the thesis sized reply, but I was bouncing back and forth between tasks and didn't have time to really chop and edit for brevity lol.

Best,
- E Patton

 

[JoeyC]

Very good detailed explanation. Thank you! Do you know if there are any other departments anywhere that use a system like this? Now I am wondering about the radio software and hardware that is used to bring this dispatcher trunking all together. Does LASD get radio/software support from one of the big radio guys or is there a guru within the department that keeps everything working? Thanks again.

 

[inigo88]

What I don't understand still however, is when you mention how a channel is assigned and the idea that the channel is otherwise "floating in space".

From what I can tell, "floating in space" means no dispatcher is listening to the channel. The repeater isn't connected to any dispatch console. A computer tries to dynamically shuffle channel assignments around between dispatchers based on their workload. So if your dispatch channel is unassigned and you begin talking, the computer assigns it to the least busy dispatcher (probably clipping the beginning of your transmission in the process since you didn't wait), who then may be listening to traffic on another dispatcher - and now they have two people on two different dispatch channels talking in their ear at once.

Keying up first and momentarily waiting gives the computer enough time to say "uh oh, someone wants to talk on that channel that no one's listening to. I better assign it to the least busiest dispatcher." Then if that dispatcher is right in the middle of receiving traffic on another channel, the deputy who keyed up the radio a moment ago will hear "Beep beep beep beep..."

It's almost like trunking, in a weird backwards sort of way.

I actually drove through LA tonight and got a chance to monitor a fair amount of LASD, and I was thinking about this thread and pondering the following question: The computer dynamic channel allocation system makes great sense for SCC given its low staffing levels. But from an officer safety standpoint, it seems wrong to have a bunch of deputies on a channel that is "floating in space," with no dispatcher listening on the other end. How aware are the deputies in this case, and what is their best way to get through to a dispatcher or dispatch supervisor immediately in an emergency/11-99/cover now scenario? (Sorry don't know the relevant LASD code.) How could they prevent their emergency traffic from mixing with whatever the dispatcher was currently listening to when their channel was picked up? Does an emergency trigger activation immediately go to the dispatch supervisor, or get a dedicated SCC dispatcher who isn't working multiple channels?

Edit: Too late.

 

[jrholm]

Inigo 10-33 is emergency clearance for LASD. Deputies are always monitored by their home station so it's never like they are completly uncovered. If a channel is floating and a deputy keys up (they won't quick key for 10-33 traffic) with 10-33, even if they covered someone the SCC dispatcher will automatically tell everyone else to hold the air for 10-33 traffic. That emergency request overides whatever else is going on. The computer will not assign a floating frequency to a dispatcher that is already holding 10-33 traffic.


Eric, I'm 40FT (you don't have to worry about me jamming you at any 415E's on the westend anymore ) now and would appreciate anything you got brother for me and my other partners with a rocker on the sleeve.

 

[finaldraft151]

From what I can tell, "floating in space" means no dispatcher is listening to the channel. The repeater isn't connected to any dispatch console. A computer tries to dynamically shuffle channel assignments around between dispatchers based on their workload. So if your dispatch channel is unassigned and you begin talking, the computer assigns it to the least busy dispatcher (probably clipping the beginning of your transmission in the process since you didn't wait), who then may be listening to traffic on another dispatcher - and now they have two people on two different dispatch channels talking in their ear at once.

Keying up first and momentarily waiting gives the computer enough time to say "uh oh, someone wants to talk on that channel that no one's listening to. I better assign it to the least busiest dispatcher." Then if that dispatcher is right in the middle of receiving traffic on another channel, the deputy who keyed up the radio a moment ago will hear "Beep beep beep beep..."

It's almost like trunking, in a weird backwards sort of way.

I actually drove through LA tonight and got a chance to monitor a fair amount of LASD, and I was thinking about this thread and pondering the following question: The computer dynamic channel allocation system makes great sense for SCC given its low staffing levels. But from an officer safety standpoint, it seems wrong to have a bunch of deputies on a channel that is "floating in space," with no dispatcher listening on the other end. How aware are the deputies in this case, and what is their best way to get through to a dispatcher or dispatch supervisor immediately in an emergency/11-99/cover now scenario? (Sorry don't know the relevant LASD code.) How could they prevent their emergency traffic from mixing with whatever the dispatcher was currently listening to when their channel was picked up? Does an emergency trigger activation immediately go to the dispatch supervisor, or get a dedicated SCC dispatcher who isn't working multiple channels?

Edit: Too late.

Most of the time there are very few channels "floating" around unassigned. The system was designed to ensure that an "equal work load" is distributed to each dispatcher, and that is where the point system comes into play. The concept was that a dispatcher is to work and hold their channels until everything goes Code 4 and then release or "drop" the channels where it will briefly float until the next call or return pops up. However, most dispatchers don't do this, as they prefer to hold channels and just work them. Everyone has a few channels they they like to work, so usually all 17 working dispatch channels will be assigned and sitting on someone's console. All all of the busy channels will be assigned throughout the floor regardless, since non stop radio and data traffic prevents a dispatcher from dropping them. SCC usually has 2-4 trainees working the floor on any given shift, so their trainers will ensure they have plenty of channels on their console.

Even if there is no radio traffic, SCC dispatchers are still receiving a constant flow of data on their consoles from each dispatch channel they are holding, so with non-stop data being received, the channel is almost always going to have a home. In the event a channel is floating, it is assigned to a console the second a call, return or message pops up, or simply when a unit keys their mic.

Radio traffic vs data traffic;
Any time field personnel run a plate on their MDT that has a "hit" or warrant on it, SCC receives the same information on their screen. It is then the dispatchers responsibility to get a status on the return. Same scenario when a person is ran for wants/warrants on an MDT. The dispatcher receives the same info on their screen and will then cross reference the name and DOB that was ran with the information that was returned on the name. If there is a match for warrants, parole or probation, restraining orders, etc SCC will then ask status from the field unit. When a name is checked for wants/warrants the system simultaneously runs the name through 7 different databases. Each database can produce up to 10 pages of returns (especially when a common name is ran) so even if the dispatcher isn't talking, they're "paging" through returns and verifying whether or not a person has wants/warrants, on parole/probation, etc. The amount of units in the field running names and plates can produce massive data (LASD operates over 25 sub stations, so there is almost always data activity) so even if the radio is quiet, the channel is still "active."

In an emergency or "10-33" situation, a unit simply needs to say 10-33. (or "give me the patch") - 10-33 freezes everything and the dispatcher will then focus on the emergency. Their console partner will then pick up the other channels without the emergency, clear them and pick up where the other dispatcher left off.

I can see where the idea of a dispatch channel floating around "unassigned" or not currently being monitored to be an officer safety issue, but if there is no traffic or data, there is nothing to listen to or monitor. Not even dead air. In the event a unit goes "10-33" on a channel that is floating, it will land on a console in the same manner as previously mentioned. If the dispatcher is talking or receiving radio traffic they will still hear the 10-33 announcement (half duplex mode allows for the dispatcher to talk and hear traffic at the same time without ever having to let off their transmit button) and they will go from there. When 10-33 traffic comes in, a dispatcher will immediately hit a button that sends an alert across the room and on the SCC "Bridge" to let everyone know they have 10-33 traffic. This puts the console in "emergency pass mode" and prohibits their console from being assigned new channels until they go back into "normal" ready mode. During the course of the emergency a supervisor or SCC Watch Sergeant will "dupe" or clone the console with the emergency, which allows them to see and hear exactly what the dispatcher is seeing and hearing. "Duping" enables you to talk back and fourth between the SCC supervisor or W/Sgt and it's common for them to relay instructions, requests or sometimes even "demands" for you to relay to field units during the emergency. It can get a tad hectic when you have 6 units talking at once, the station talking to you on the hotline and a supervisor in your ear, but you just learn to roll with the changes and remain fluid.

Emergency Triggers or "E-Trigs" assign in the same manner. When a radio's E-Trig is depressed it automatically switches the radio to the E-Trig Channel (483.2875) and will transmit the units ID and last location onto the dispatchers screen. It will continue to transmit an E-trig message every 3-5 seconds until the radio is shut off and turned back on to reset. The E-trig channel is dedicated solely to this, but the channel itself is usually also sitting on someones console. If you monitor the E-Trig channel you will often hear it being held with normal dispatch channels and hear calls going out all over the County.

 

[inigo88]

Thanks very much for both the detailed responses. I didn't really mean to come off so critical or raise the officer safety question, but in the absence of knowing more information about SCC and how fast "floating" channels can be sent to a console and picked up, I honestly wasn't sure how easy it would be to hear an abrupt "10-33" or "give me the patch," or if that would ever make it to a live dispatcher in time. It sounds like it's lightning fast. It's a pretty ingenious system, and basically takes the idea behind trunking (where everyone's radio floats in limbo until there's traffic on their channel) and instead applies it to how the channels themselves are assigned to the dispatch consoles.

The E-trig channel is dedicated solely to this, but the channel itself is usually also sitting on someones console. If you monitor the E-Trig channel you will often hear it being held with normal dispatch channels and hear calls going out all over the County.

Thanks for answering this, it was another question I had as well. I indeed did hear routine dispatch traffic on the E-Trig channel, and figured that particular dispatcher was working both. But I didn't realize that if you monitor multiple channels on your console they all share each other's traffic (basically all the channels they're holding are temporarily patched together).

 

[finaldraft151]

Thanks very much for both the detailed responses. I didn't really mean to come off so critical or raise the officer safety question, but in the absence of knowing more information about SCC and how fast "floating" channels can be sent to a console and picked up, I honestly wasn't sure how easy it would be to hear an abrupt "10-33" or "give me the patch," or if that would ever make it to a live dispatcher in time. It sounds like it's lightning fast. It's a pretty ingenious system, and basically takes the idea behind trunking (where everyone's radio floats in limbo until there's traffic on their channel) and instead applies it to how the channels themselves are assigned to the dispatch consoles.

..No worries at all - The system and the way it operates sounds baffling and impractical, and the use of a busy tone is a topic of frustration too, since it's unique to LASD (and can be frustrating to the scanner listener and field personnel) so I know where you're coming from. It used to drive me nuts when I listened to a scanner. Beeps, tones, a constant array of channels changing from dispatcher to dispatcher, hearing Norwalk one second and then Lost Hills the next, it made no sense at all.

Here is a link to a previous thread about E-Trigs that I posted with more info and input/details from other members.

http://forums.radioreference.com/gr...24-lasd-e-trigs-e-mdt-code-6-activations.html

 

[jrholm]

Inigo also the asignment of a floating channel to a console is lightning fast. Field units don't even recognize it usually.

 

[inigo88]

Inigo also the asignment of a floating channel to a console is lightning fast. Field units don't even recognize it usually.

Very cool!