San Diego RCS OTAP

[P25Radio]

Wonder what talk group or channel the RCS uses to reprogram radios or does each department have their own assigned
channel?

 

[d119]

OTAP is extremely slow and painful, and I doubt it's even being used. It requires the radios to be authenticated in the back end and a whole bunch of other rigamarole to make it work (IP addresses, etc.)

The FNE initiates the session on whatever channel is available, just like a voice call. It's not a "talkgroup" per-se, but more of a function.

It also requires the subscriber radio to have the feature in the flashcode, and I seriously doubt any of these agencies paid for anything they didn't absolutely need.

Less features = more radios.

 

[f40ph]

SLOW and PAINFUL is right. OTAP isn't recommended for fleet updates. One radio here and there might save someone a drive but that's about it.
Our system just requires the radio be sitting on any trunking channel. The update happens in the background via the trunking data channel.

 

[d119]

I think it actually establishes a P25 data call on what would normally be a voice channel, but still - the transfer rate is crap.

 

[f40ph]

That's very interesting. I've watched my radio while receiving OTAP programming and it did receive voice traffic, maybe it pauses data during voice on the selected TG?

 

[d119]

Entirely possible. You certainly wouldn't want the thing running an OTAP update during a critical incident, so perhaps it does it that way so that's not a concern.

I have no personal experience with OTAP in a Motorola environment such as the RCS, but I would expect it to use packet data for the transfer rather than the control channel, as I would think it would cause an undue amount of contention on the control channel and impair system accessibility.

Most of the OTAP I'm familiar with does so over LTE or another broadband-type connection (WiFi in my particular case). If the radio has an update pending and it comes within WiFi range, the user is prompted if they want to receive the update or not so it doesn't drop them in the middle of a critical call. OTAP over LTE/BB happens in a matter of seconds.

 

[WayneH]

OTAP/POP25 utilizes the standard packet data system built into the ASTRO network (hence IV&D, integrated voice and data). Data calls are a separate thing and indicated specifically in the P25 CAI. It's a convoluted side of the infrastructure in how it all works but basically a radio will do a context activation after registering on the system; this process is similar to how a computer requests an IP address when it isn't assigned a fixed/static address. There's an assortment of infrastructure that makes this all happen (GGSN, PDR/PDG, Border Router) so that the system keeps track of the the radio network so the data calls can be sent efficiently. The device called the border router is the last router before the IP data that a subscriber initiates is introduced to the network where your data services are (so KMF, Radio Management, AVL, etc). To add to that, services such as AVL and OTAP can use encrypted data via an added device in the packet data network. The KMF is natively encrypted so these other services rely on a packet data encryption gateway to handle the other packet data services. This packet data network is often connected to the customer's private network where their CAD system resides to there's inter-operation between CAD and subscriber database (UCS aka Provisioning Manager) (for example).

From a scanner perspective you'll have no idea this is going on unless you monitor in conventional. Data calls don't utilize groups, but you will see radio IDs during the calls. Channels by default can handle both voice and data, with voice taking priority and you can enable the ability to pre-empt a data call for voice if the system loads up. Voice and data can be an and/or if you so want to dedicate a channel for data (see enhanced below). Calls are sequenced like people lining up at a bank.

Then there also an enhanced data format (you'll see it in a flashcode) that's typically associated with AVL and adds abilities like the ability to send location on PTT. When AVL is used on a system you'll see quite a lot of data calls. There are a lot of options as far as location goes, and some can send data often.

The smart way to do OTAP is to sync over WIFI to the radio management server and get the programming jobs that way.

 

[P25Radio]

Very interesting information on the subject and informative.

 

[2wayfreq]

Unless they have a good deal on Radio Manager Server, it's very expensive for licenses. I believe you can run it though Wi-Fi/Hot Spot networks for much faster multi-radio updates. Using Trunking Data speeds for OTAP is not ideal in a huge network.

 

[jmarshl]

OTAP/POP25 utilizes the standard packet data system built into the ASTRO network (hence IV&D, integrated voice and data). Data calls are a separate thing and indicated specifically in the P25 CAI. It's a convoluted side of the infrastructure in how it all works but basically a radio will do a context activation after registering on the system; this process is similar to how a computer requests an IP address when it isn't assigned a fixed/static address. There's an assortment of infrastructure that makes this all happen (GGSN, PDR/PDG, Border Router) so that the system keeps track of the the radio network so the data calls can be sent efficiently. The device called the border router is the last router before the IP data that a subscriber initiates is introduced to the network where your data services are (so KMF, Radio Management, AVL, etc). To add to that, services such as AVL and OTAP can use encrypted data via an added device in the packet data network. The KMF is natively encrypted so these other services rely on a packet data encryption gateway to handle the other packet data services. This packet data network is often connected to the customer's private network where their CAD system resides to there's inter-operation between CAD and subscriber database (UCS aka Provisioning Manager) (for example).

From a scanner perspective you'll have no idea this is going on unless you monitor in conventional. Data calls don't utilize groups, but you will see radio IDs during the calls. Channels by default can handle both voice and data, with voice taking priority and you can enable the ability to pre-empt a data call for voice if the system loads up. Voice and data can be an and/or if you so want to dedicate a channel for data (see enhanced below). Calls are sequenced like people lining up at a bank.

Then there also an enhanced data format (you'll see it in a flashcode) that's typically associated with AVL and adds abilities like the ability to send location on PTT. When AVL is used on a system you'll see quite a lot of data calls. There are a lot of options as far as location goes, and some can send data often.

The smart way to do OTAP is to sync over WIFI to the radio management server and get the programming jobs that way.

I agree. I just received a very large codeplug from radio management via WIFI in under 2 minutes.