How does the LAPD radio systems/channels work?

[Silvesteeer]

Hey everyone! This might be a very stupid and over-simplified question but I have a hard time grasping how exactly LAPD officers communicate between the Tacticals, Simplex, Fallback and Dispatch channels.

Can Officers broadcast emergency messages or is it up to the Dispatchers to forward the help call to other units? In what situations are Tactical channels deployed? When do you have to use fallback channels and when do you tune in to the fallback channels?

If somebody could detail what exactly happens when an example OIS occurs or maybe even a pursuit of a vehicle, I'd really appreciate it.

Sorry if it's a stupid question and thank you for reading!

 

[ElevatorsAndRadios]

Routine communications goes on dispatch channels. Tactical channels are used to handle extended incidents or tactical operations.

 

[monitor142]

The LAPD is a very large UHF wide area simulcast system and their primary mode of comms. Think of it as multiple layers of the onion.

Dispatch: Primary (area driven) channels. (Simulcast and voted)
Tacticals: As E&R noted, extended or special operations (Simulcast and voted)
Fallback: A backup system geographically located for each division in the event their primary system is down (Repeated)
Simplex: Simply point to point or radio to radio bypassing the radio infrastructure. Short distance comms

It's a very elaborate Motorola conventional system. Two fully redundant dispatch centers that operate on a daily basis but can back each other up.

The next chapter is their 700MHz trunked system. It's still a work in progress but since the T-Band spectrum (470-512MHz) won't be taken away, they may only use the trunked system for special events and operations. Deployment of multi-band portables and mobiles is in progress if not completed for LAPD.

 

[jtech48]

Can Officers broadcast emergency messages or is it up to the Dispatchers to forward the help call to other units? In what situations are Tactical channels deployed? When do you have to use fallback channels and when do you tune in to the fallback channels?

There's two scenarios for what you asked. First, an officer cannot broadcast an emergency message unless they activate the emergency trigger. At that point, the radio switches to a pre-programmed channel (for LAPD it's channel 50 or "Emergency") and then a hot mic is activated for 10 secs. If the radio is not assigned, the Bureau Communications Coordinator (BCC) will make an initial emergency activation broadcast for an unassigned "ROVER". If the radio is assigned, the respective dispatcher will broadcast the activation broadcast on their division and emergency channel. If after the initial activation broadcast no acknowledgement is made the dispatcher proceeds to broadcast an officer needs help call.
Another scenario is when an officer themselves requests for help, the dispatcher will be the one to broadcast the emergency on all bordering divisions as well as AIR/K9, to notify any units who may be in the area, this is referred to as "Area Group".

There are different types of tactical channels for LAPD, the 2 most used are Bureau and Citywide. Citywide for the most part are mostly used on a scheduled or pre-planned basis. However, during instances of fluid situations which may span over a few divisions or there's concerns about radio coverage where a bureau tactical may not be practical, these are used on a first-come first-serve basis. Bureau tactical channels are similar except that the reception coverage is best for the bureau in which they are labeled for (ex. West Bureau Tac for West LA) and these are much more readily available for unusual occurrences. Fallback or simplex (LAPD uses interchangeably) are division wide car-to-car frequencies used on a case by case basis. The most common time this is used is when officers respond to a priority call and an air unit responds. You will hear the air unit request officers to switch to simplex in order to speak directly without using up the base frequency.

Hope this helps, feel free to DM me if you want to discuss further.

J

 

[Aggie_ita]

There's two scenarios for what you asked. First, an officer cannot broadcast an emergency message unless they activate the emergency trigger. At that point, the radio switches to a pre-programmed channel (for LAPD it's channel 50 or "Emergency") and then a hot mic is activated for 10 secs. If the radio is not assigned, the Bureau Communications Coordinator (BCC) will make an initial emergency activation broadcast for an unassigned "ROVER". If the radio is assigned, the respective dispatcher will broadcast the activation broadcast on their division and emergency channel. If after the initial activation broadcast no acknowledgement is made the dispatcher proceeds to broadcast an officer needs help call.
Another scenario is when an officer themselves requests for help, the dispatcher will be the one to broadcast the emergency on all bordering divisions as well as AIR/K9, to notify any units who may be in the area, this is referred to as "Area Group".

There are different types of tactical channels for LAPD, the 2 most used are Bureau and Citywide. Citywide for the most part are mostly used on a scheduled or pre-planned basis. However, during instances of fluid situations which may span over a few divisions or there's concerns about radio coverage where a bureau tactical may not be practical, these are used on a first-come first-serve basis. Bureau tactical channels are similar except that the reception coverage is best for the bureau in which they are labeled for (ex. West Bureau Tac for West LA) and these are much more readily available for unusual occurrences. Fallback or simplex (LAPD uses interchangeably) are division wide car-to-car frequencies used on a case by case basis. The most common time this is used is when officers respond to a priority call and an air unit responds. You will hear the air unit request officers to switch to simplex in order to speak directly without using up the base frequency.

Hope this helps, feel free to DM me if you want to discuss further.

J

I have a new question (I can't dm)
It's a dumb question but... Can officers hear each other on their normal dispatch channel?

 

[Z_DEO5]

I have a new question (I can't dm)
It's a dumb question but... Can officers hear each other on their normal dispatch channel?

Yes, the officers can hear each other on their dispatch channels. It is LA County sheriffs department that has the radio system where sometimes the officers just hear the beep.

 

[f40ph]

The LAPD is a very large UHF wide area simulcast system and their primary mode of comms. Think of it as multiple layers of the onion.

It's a very elaborate Motorola conventional system. Two fully redundant dispatch centers that operate on a daily basis but can back each other up.

They have two staffed dispatch centers?

 

[Engine104]

They have two staffed dispatch centers?

Yep.. One in DTLA and one out here in the SFV in West Hills.

 

[jtech48]

I have a new question (I can't dm)
It's a dumb question but... Can officers hear each other on their normal dispatch channel?

Yes they can but they do not have the ability to switch to direct on dispatch channels like LASD can.

 

[ScanFanEd]

Would anyone know if it is likely that LAPD will continue to be non-encrypted for the foreseeable future?

 

[Peter_SD911]

Would anyone know if it is likely that LAPD will continue to be non-encrypted for the foreseeable future?

Yes, for the foreseeable future.
They need new equipment first.

 

[KG6GTH]

Yes, for the foreseeable future.
They need new equipment first.

New Equipment??? They Have APX-8000's and APX-8500's that are Encryption Capable?

To Answer ScanFanEd: I would say Encryption in the LA Region is a given and its coming to those who are not using it already.... That being said, its always a possibility... :O)

 

[ladn]

New Equipment??? They Have APX-8000's and APX-8500's that are Encryption Capable?

To Answer ScanFanEd: I would say Encryption in the LA Region is a given and its coming to those who are not using it already.... That being said, its always a possibility... :O)

LAPD is very political and is controlled by the Police Commission who serves at the pleasure of the mayor/city council.

While I expect encryption to creep in, its progress will be mitigated by the department overseers in the name of "transparency" or "public's right to know".

 

[Peter_SD911]

New Equipment??? They Have APX-8000's and APX-8500's that are Encryption Capable?

To Answer ScanFanEd: I would say Encryption in the LA Region is a given and its coming to those who are not using it already.... That being said, its always a possibility... :O)

Well then it's just a "flip of the switch"?
APX's are not all of the equation.
How about the money to do this process?
Cost of manpower?
L.A is broke...and it may just be cheaper to educate the forces to use MDT's or keep P.I. off the clear air.
E is not the only option.

Scan Sexy...
Enjoy the "E" on the dance floor.