[CORRECT AS IS] Datalink Update Rate

The datalink update rate is afaik incorrect in current OB. Here is a track where a pop up contact very close to me and awacs takes 12 seconds to show in SA page. Radar is silent and there is no extrapolation, just pure datalink with awacs.

There have been some conversations in youtube about this and a former hornet pilot that agrees that even 1 second measurement is wrong.

Hope it helps. Thanks.

datalink update rate.trk

Are you suggesting that an AWACS would provide an update rate higher than every 1 second? Or am I misunderstanding?

The update rate is not correct, it is currently 12 seconds which is crazy. I think he refers about something that went on today in youtube, I don't know if it is even something that I should talk about here, given current rules. But a fighter pilot suggested that 12 seconds isn't correct, and that measuring link16 is seconds in absurd, too long. I'm really confused about how things work in this community to be honest.

Please expand on what and why you think it's wrong. Is it just awacs? Or all of L16?

Please expand on what and why you think it's wrong. Is it just awacs? Or all of L16?

There are papers that have been shared here and there that suggest that Link16 has 300ms update rate. Here is a link of one of them, the others are more confidential I think. Anyway, I am pretty sure ED knows this already, it's a matter of how they wish to simulate things and what engine limitation there is. I honestly don't think this will change, seems like one of those sensitive things that ED is not open to external sources. In my humble opinion it is worth looking. https://drive.google.com/file/d/1eaxwaWtnvefME32qajM3r6Wla8tDhHr1/view

You are confusing L16 message transmission capabilities with awacs capabilities. You could transmit 300 messages a second, but if your radar takes 10 seconds to complete a rotation and update a target, then that target will be updated every 10 seconds.

That's why I asked if this is for all of L16 or just the awacs.

You are confusing L16 message transmission capabilities with awacs capabilities. You could transmit 300 messages a second, but if your radar takes 10 seconds to complete a rotation and update a target, then that target will be updated every 10 seconds.

 

That's why I asked if this is for all of L16 or just the awacs.

Santi, It is for all Link16, I'm flying at this very second and PPLI also updates each 12 seconds, which according to this hornet pilot isn't right.

Another way to check is to lock a maneuvering target in STT (so the F/F donor gets continuous radar updates) and have another F-18 check their radar and SA pages for updates.

Another way to check is to lock a maneuvering target in STT (so the F/F donor gets continuous radar updates) and have another F-18 check their radar and SA pages for updates.

No need, PPLI is also updating each 12 seconds.

Seems like "everything" updates every 12 sec. including RWR (angular update):D

… just a snotty remark.

Seems like "everything" updates every 12 sec. including RWR (angular update):D

… just a snotty remark.

Good catch!!! Maybe that will help ED track the issue.

Good catch!!! Maybe that will help ED track the issue.

They are aware of lots of issues that for whatever reasons are put on backburner. It's not easy to make a point once you enter any sensitive material twilight zone. No one that knows will open their mouths. Our local physicists, engineers and theoreticians can argue for years (it happened:smilewink:) but w/o public docs... Sometimes, I wish they just made stuff up based on their own common sense.:music_whistling:

Meanwhile, I'd better get my dial-up DL going before I need it.

They are aware of lots of issues that for whatever reasons are put on backburner. It's not easy to make a point once you enter any sensitive material twilight zone. No one that knows will open their mouths. Our local physicists, engineers and theoreticians can argue for years (it happened:smilewink:) but w/o public docs... >

I support that 100%, you're right. Still think though that this can be tweaked. Datalink update rate of 12 seconds is just as credible as a 360° radar on a fighter :)

They are aware of lots of issues that for whatever reasons are put on backburner. It's not easy to make a point once you enter any sensitive material twilight zone. No one that knows will open their mouths. Our local physicists, engineers and theoreticians can argue for years (it happened:smilewink:) but w/o public docs... Sometimes, I wish they just made stuff up based on their own common sense.:music_whistling:

Meanwhile, I'd better get my dial-up DL going before I need it.

But by current standards link 16 is slow. That why they are now looking at a replacements.

IF your using lOS VHF/UHF frequencies that your only looking at either 2.4k or 16k speeds. Dial up has a max theoretical capability of 56K.

IF using more modern Link 16 transmission techniques such as network hosted via TCP/IP protocols then only then are you looking at faster then dial up speeds to 115 Kilobits per second.

I support that 100%, you're right. Still think though that this can be tweaked. Datalink update rate of 12 seconds is just as credible as a 360° radar on a fighter :)

Even between AWACS and the rest I wouldn't expect a delay like this. Who knows...

But by current standards link 16 is slow. That why they are now looking at a replacements.

 

 

IF your using lOS VHF/UHF frequencies that your only looking at either 2.4k or 16k speeds. Dial up has a max theoretical capability of 56K.

 

IF using more modern Link 16 transmission techniques such as network hosted via TCP/IP protocols then only then are you looking at faster then dial up speeds to 115 Kilobits per second.

OK then, 12 secs it is.:)

looking further into it It seems to come from the general description of JTIDS ( which fall under Link 16 umbrella)

" It produces a spread spectrum signal using Frequency-shift keying (FSK) and Phase-shift keying (PSK) to spread the radiated power over a wider spectrum (range of frequencies) than normal radio transmissions. This reduces susceptibility to noise, jamming, and interception. In JTIDS Time Division Multiple Access (TDMA) (similar to cell phone technology), each time interval (e.g., 1 second) is divided into time slots (e.g. 128 per second). Together, all 1536 time slots in a 12-second interval are called a "frame". Each time slot is "bursted" (transmitted) at several different carrier frequencies sequentially. Within each slot, the phase angle of the transmission burst is varied to provide PSK. Each type of data to be transmitted is assigned a slot or block of slots (channel) to manage information exchanges among user participation groups. In traditional TDMA, the slot frequencies remain fixed from second to second (frame to frame)."

It would seem that "12 seconds" then is perhaps not necessarily entirely a speed limitation but because of specific transmission processes.

looking further into it It seems to come from the general description of JTIDS ( which fall under Link 16 umbrella)

 

 

 

" It produces a spread spectrum signal using Frequency-shift keying (FSK) and Phase-shift keying (PSK) to spread the radiated power over a wider spectrum (range of frequencies) than normal radio transmissions. This reduces susceptibility to noise, jamming, and interception. In JTIDS Time Division Multiple Access (TDMA) (similar to cell phone technology), each time interval (e.g., 1 second) is divided into time slots (e.g. 128 per second). Together, all 1536 time slots in a 12-second interval are called a "frame". Each time slot is "bursted" (transmitted) at several different carrier frequencies sequentially. Within each slot, the phase angle of the transmission burst is varied to provide PSK. Each type of data to be transmitted is assigned a slot or block of slots (channel) to manage information exchanges among user participation groups. In traditional TDMA, the slot frequencies remain fixed from second to second (frame to frame)."

 

It would seem that "12 seconds" then is perhaps not necessarily entirely a speed limitation but because of specific transmission processes.

Thanks, it took me 5 min. to digest it but I think I got it.

Very cool information indeed! I wonder why the hornet pilot on youtube was so suprised to read that in dcs is 12 secs.

https://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodm/465001r1p.pdf

Excerpt from Battlespace Technologies: Network-enabled Information Dominance

By Richard S. Deakin - 2010

Don't know what other nuances there are the would permit Link 16 to update at a faster interval when looking at the above. But multiple public open source info seems to point to transmission update only every frame ( in other words 12 seconds).

Hence probably why ED decided to simulate like it is in DCS.

Santi, It is for all Link16, I'm flying at this very second and PPLI also updates each 12 seconds, which according to this hornet pilot isn't right.

Here you go:

PPLIs are automatically transmitted by the MIDS terminal on the main net at a predetermined rate (normally every 12 sec.).

Thanks Guys. I'm really happy to know this is not a bug but a real thing, it makes the sim experience much better. I am still curious to know why a fighter pilot would say different. But who knows.

Here you go:

Santi, I didn't catch where that quote comes from.