IFF system modeled in depth

[pabletesoy]

A more deeply IFF system. In DCS it is too accurate with no possibility of failure. Right now it is lagging behind other functions.
I guess there is already a thread about this, although I haven't found it.

 

Cheers!

Edited February 14 by pabletesoy

[Northstar98]

+1, a couple of third parties (RAZBAM and Deka) already have their own implementations that (at least in RAZBAM’s case, not that familiar with Deka) do everything that would be necessary.

Though the other important aspect is having this apply to the AI, not only with the ability to assign codes, but also to have the AI perform interrogations as part of their identification process. Right now they appear to be able to instantly identify and classify everything they detect with perfect accuracy. With hostile/friendly being a simple coalition check and not accounting for things like IFF or other means of identification (e.g. visual, even if approximated).

This would also open up doctrinal considerations when against unknown targets - for instance, whether the AI should only fire at contacts positively identified as hostile, or whether they should fire at anything not identified as friendly.

[Miro]

1 hour ago, pabletesoy said:

In DCS it is too accurate with no possibility of failure.

 

Try F-15 E then...

[lmp]

To me the most obvious simplification is that all aircraft, regardless of reality, have a magical transponder that works with every interrogator. Even planes that shouldn't have a transponder at all. It's great to simulate system and user errors, false positives due to a friendly along a similar azimuth etc., but right now we're missing much simpler and more obvious stuff.

I think the key is that getting the AI to work in an unreliable IFF environment is a much bigger job than creating the unreliable IFF environment in the first place. We would need a comprehensive set of RoE options for the AI, including air defences, and we would need to explore the possibility of friendly AI shooting us down in error.

[peterbrownbyu]

I agree, add it to the list. I'd love to see it modeled too, and I hate to be cynical but there's like 10 other issues, each of them 15 years old, that need to be addressed first. Given ED's development timelines, I'd rather they pushed it back

Though I'm with you, it's irritating that only like 3 modules have it modeled

[Tippis]

A lot of it will come down to what you mean by “in depth”.

IFF is one of those “if you open the black box, you will be put into one yourself” topics, so that depth will obviously never happen. At the other end of the spectrum, the most shallow level of where you have to input and match codes — provide input, and get the expected outcome and what happens in the black box in-between is ignored — exist in a handful of aircraft already. But the lesson there is that it can cause incompatibilities with aircraft that don't have the same detail, so it falls back on magic knowledge anyway.

Having it be capable of failure would increase the depth ever so slightly, but then you'd need good info on why it can fail, but without going into details, and the game would probably have to be expanded in other areas to make room for that. For instance, the issue of the signal not getting through is actually already in the game — you can see it happen with TACAN, for instance. But that failure is a simple matter of line-of-sight and range attenuation, and the way those are handled wouldn't really come into effect if we're looking at aircraft querying each other. It could be faked with randomisation, of course, but those tend to end up over-modelled, or people won't notice. The AI issues discussed above fall into a similar “there, but would have to be expanded” category.

It also depends on what systems you want to include. If it's just giving the IFF code panel a purpose, then that's a separate thing from stuff like Hornet's NCTR mode, but maybe that's unique enough that it's better handled on a per-module basis.

[Dragon1-1]

2 minutes ago, Tippis said:

IFF is one of those “if you open the black box, you will be put into one yourself” topics, so that depth will obviously never happen.

On the aircraft that we have, it's far from it. Basically, IFF has three modes, one of which is basically a civilian transponder, two are well documented and one is an encrypted version of the civilian transponder. Friggin' Wikipedia has a good overview of how all the IFF modes work, complete with how the pulses are encoded. Even the range of frequencies is known.

In general, an IFF system is basically a digital radio transceiver that listens for a specific interrogation pulse and then replies in a way that's determined, in a fairly transparent way, by the position of switches in cockpit and (for mode 2, which replies with the tail number) in the avionics bay. Mode 4, the encrypted one, works the same, but now the code for both interrogation and reply is secret. Two codes are carried: A and B, changing according to the SOP (for instance, every 12 or 24 hours). A is the current one, B is the next one in rotation, if you're flying past the scheduled code change, you flip the switch when that happens. There's also a small, random delay to a mode 4 response that ties into the code, this is to make locating the aircraft via its IFF response harder. As far as failure modes go, they're basically the same as any other radio, plus accidental zeroization of the secret codes.

Properly implementing the Western IFF system would not be particularly difficult, compared to other systems of the same complexity. For Soviet ones there are some resources out there, and everything but SPZO-2M and Parol was compromised by Vietnam, so the docs for those might be declassified along with Combat Tree (which we may be getting on the Phantom). In any case, the Soviet systems gave the pilot relatively little control over them. MiG-29A supposedly even had automatic interrogation, and would inhibit firing or even locking onto an aircraft it recognized as friendly (with an override button on the stick, thankfully).

[Lt_Jaeger]

 

44 minutes ago, Tippis said:

IFF is one of those “if you open the black box, you will be put into one yourself” topics, so that depth will obviously never happen

I have to agree. Modes and Codes are easy enough to implement, but if you go down with the technical issues inherent with IFF systems.... FRUIT, Garbeling, Cell resolution, Target count spoofing ... are some things that pop up in my mind without thinking too long about it. It is way too long that I had any business with IFFs to be proficent, but I remember there were a huge load of problems involved.

[Tippis]

12 hours ago, Dragon1-1 said:

In general, an IFF system is basically a digital radio transceiver that listens for a specific interrogation pulse and then replies in a way that's determined, in a fairly transparent way, by the position of switches in cockpit and (for mode 2, which replies with the tail number) in the avionics bay. Mode 4, the encrypted one, works the same, but now the code for both interrogation and reply is secret. Two codes are carried: A and B, changing according to the SOP (for instance, every 12 or 24 hours).

Quite, and that's where we get into the black box. But as mentioned, you don't really need to open that box as long as the input and outcome matches what's expected — i.e. right code = thumbs up; wrong code = thumbs down. It's the failures that get tricky because you'd have to know how robust both ends are to weak or noisy signals. But then again, that also mostly comes down to a matter of ambition: much like how half the planes completely and deliberately do laser-guided weapons wrong because [reasons], there's nothing to say that that kind of detail in the error simulation must exist. Just doing IFF a little more — say by making range and aspect a factor — goes a long way since the starting point is zero in most cases.

Edited February 22 by Tippis

[QuiGon]

With more and more third party devs developing their own custom IFF system, it is really really getting time for ED to actually implement an IFF system to the core of DCS that everybody can use in order to avoid having lots of different but incompatible third party solutions for proper IFF simulation. Just my 2 cents.

[Northstar98]

16 minutes ago, QuiGon said:

With more and more third party devs developing their own custom IFF system, it is really really getting time for ED to actually implement an IFF system to the core of DCS that everybody can use in order to avoid having lots of different but incompatible third party solutions for proper IFF simulation. Just my 2 cents.

Well, one thing that was nice to see is that the Mirage F1 was made compatible with RAZBAM's IFF implementation. If more 3rd parties follow suite then couldn't that be the standard? Though it would be somewhat unprecedented having a 3rd party develop what should be a core technology.

I think it would be a shame if a system that basically does everything required (at least from a NATO IFF perspective, but seeing as RAZBAM is working on the MiG-23MLA, perhaps we'll see Soviet equipment too) needed to be reinvented by ED, especially when they've seemed somewhat averse to IFF in the past.

11 hours ago, Tippis said:

Just doing IFF a little more — say by making range and aspect a factor — goes a long way since the starting point is zero in most cases.

This I think is the key here, even a simplistic IFF simulation* would go a long way, though we already have modules that already (at least IMO) do everything required.

*

Spoiler

For instance, with NATO Mk XII systems:

For modes 1-3/A, then so long as:

• The interrogated aircraft has:

  • Their transponder on (i.e master mode switch to NORM or LOW, though with lower sensitivity range is reduced)

  • Their transponder set to respond to whatever mode being interrogated (M1/M2/M3 control switch on)

  • Transponder functional (i.e. not damaged).

• The interrogating aircraft has:

  • Their interrogator on

  • Their interrogator functional (i.e. not damaged).

  • Their interrogator set to interrogate modes 1/2/3, with whatever code.

• Then:

  • If a response is given on the right mode and the codes match: positive (friendly) indication (e.g. green circle with the mode number inside for the F-16, a bar above and below the target in the F-4E and F-14).

  • If a response is given on the right mode and the codes don't match: ambiguous indication (e.g. yellow square with mode number inside for F-16, a bar below the target in the F-4E and F-14).

  • If no response is given (for instance, transponder not on, not set to respond to the mode being interrogated, incompatible transponder, damaged, etc) then obviously there won't be an indication at all.

 

• For mode 4, then so long as:

  • Interrogated aircraft has IFF master mode to NORM or LOW.

  • Interrogated aircraft has mode 4 control switch on.

  • Both interrogator and interrogated have the same key (A or B) selected. Note that the B key is the next day's A key - if aircraft x takes off before 00:00Z but is still flying after 00:00Z and aircraft y takes off after 00:00Z, then aircraft x's B key will correspond to aircraft y's A key, if that makes sense. See Notso's comment on Discord.

  • Both interrogator and interrogated belong to the same coalition (only thing we need to do to approximate the encrypted nature of mode 4, which is how it already works in DCS)

  • Transponder/interrogator fully functional (i.e. not damaged and codes not zeroized (i.e ZERO not selected on M4 control switch and master ZEROIZE switch not enabled (if applicable), HOLD selected (if IFF mode knob set to off/aircraft shut down)).

[QuiGon]

2 hours ago, Northstar98 said:

Well, one thing that was nice to see is that the Mirage F1 was made compatible with RAZBAM's IFF implementation. If more 3rd parties follow suite then couldn't that be the standard? Though it would be somewhat unprecedented having a 3rd party develop what should be a core technology.

That would bring a whole new set of issues with it if a 3rd party dev would be responsible for a core piece of tech in DCS (thinking of support, maintainance and ownership here). I guess it would still be better than nothing though.

Edited February 23 by QuiGon

[Northstar98]

2 minutes ago, QuiGon said:

That would bring a whole new set of issues with it if a 3rd party dev would be responsible for a core piece of tech in DCS (thinking of support, maintainance and ownership here). I guess it would still be better than nothing though.

It would - like I said, this would be unprecedented.

I just feel it would be a shame if that work had to be done away with, if ED produce their own implementation.

[lmp]

I think the sooner ED sits down with all the interested third parties and comes up with a common system that everyone switches to the better. To me realistic sensor implementation is now the thing that separates the good modules from the great ones. I'm sure not everyone feels the way I do, but for the most part the FMs in different modules seem pretty believable to me. But after seeing how the Phantom's radar will be modelled and what for example RAZBAM does, and then comparing it to what we had in the F-5E and the MiG-21... It's hard to go back to the old planes. I want to see the same, high level of quality in all the aircrafts' sensors and IFF is a part of that as well.

[Northstar98]

1 minute ago, lmp said:

I think the sooner ED sits down with all the interested third parties and comes up with a common system that everyone switches to the better. To me realistic sensor implementation is now the thing that separates the good modules from the great ones. I'm sure not everyone feels the way I do, but for the most part the FMs in different modules seem pretty believable to me. But after seeing how the Phantom's radar will be modelled and what for example RAZBAM does, and then comparing it to what we had in the F-5E and the MiG-21... It's hard to go back to the old planes. I want to see the same, high level of quality in all the aircrafts' sensors and IFF is a part of that as well.

Definitely agree with that.

[Dragon1-1]

HB is already working with ED on a better RWR implementation. There's no reason for RAZBAM not to work with them on the IFF, particularly if they can simulate how the Soviet systems work.

The old modules, however, that's another story. Old modules are old, and that means implementing things in the modern way is not going to be easy. Mag3, at least, expressed interest in a completely new MiG-21 module (of course, they don't work very fast), but the F-5 doesn't seem to be anywhere near priority, as much as it deserves to be brought to modern standards.

[Tippis]

4 hours ago, QuiGon said:

With more and more third party devs developing their own custom IFF system, it is really really getting time for ED to actually implement an IFF system to the core of DCS that everybody can use in order to avoid having lots of different but incompatible third party solutions for proper IFF simulation. Just my 2 cents.

Oh god yes. There are so many “eh, let's just wing it” systems in DCS that either weren't originally interesting or that only received some token attention or work-around, but which have now become expected features that all modules have to do in one way or another without any unifying structure behind it.

DTC and all the settings that go into that, dynamic mission programming, laser-guided weapons, cockpit environment controls, and (in the past) such obvious things like ground radar. So much is now standard that it should be part of the core, but we're looking down the barrel of an increasingly disparate and often mutually incompatible bunch of implementations. Sure, core systems don't sell planes, but I am kind of wondering how much effort is wasted on remaking these systems that should be universal by now.

[norman99]

I too would love an accurate IFF system, but realised with the current multiplayer experience, there’s absolutely no way to make it work. (I’m specifically thinking of Mode 2,3,4 codes and their application, not transmission range, strength etc.)

If IFF systems truly relied on inputting the correct codes to function, then these would have to be provided to each aircraft in the mission briefing documentation, itself not a big problem. (The other sim we don’t mention handles this well.)

BUT, given this information has to be made available to all players, there’s nothing to stop a RED player inputting a BLUE IFF code into his aircraft, and freely flying around enemy controlled airspace, and shooting at unsuspecting aircraft that view it as a friendly, due to the IFF return.

Basically it would open a can of worms re dishonest usage that would cause chaos on multiplayer servers. Anything that attempts to prevent this, would by its nature, be fudging how IFF works.

Edited February 24 by norman99

[QuiGon]

On 2/24/2024 at 3:12 AM, norman99 said:

I too would love an accurate IFF system, but realised with the current multiplayer experience, there’s absolutely no way to make it work. (I’m specifically thinking of Mode 2,3,4 codes and their application, not transmission range, strength etc.)

If IFF systems truly relied on inputting the correct codes to function, then these would have to be provided to each aircraft in the mission briefing documentation, itself not a big problem. (The other sim we don’t mention handles this well.)

BUT, given this information has to be made available to all players, there’s nothing to stop a RED player inputting a BLUE IFF code into his aircraft, and freely flying around enemy controlled airspace, and shooting at unsuspecting aircraft that view it as a friendly, due to the IFF return.

Basically it would open a can of worms re dishonest usage that would cause chaos on multiplayer servers. Anything that attempts to prevent this, would by its nature, be fudging how IFF works.

Military Mode 4 is your answer. It's the standard IFF mode to work with for military aircraft and it doesn't use manually entered codes, but pre-defined crypto keys to prevent abuse by the enemy.

Edited February 29 by QuiGon

[WHOGX5]

On 2/24/2024 at 3:12 AM, norman99 said:

I too would love an accurate IFF system, but realised with the current multiplayer experience, there’s absolutely no way to make it work. (I’m specifically thinking of Mode 2,3,4 codes and their application, not transmission range, strength etc.)

If IFF systems truly relied on inputting the correct codes to function, then these would have to be provided to each aircraft in the mission briefing documentation, itself not a big problem. (The other sim we don’t mention handles this well.)

BUT, given this information has to be made available to all players, there’s nothing to stop a RED player inputting a BLUE IFF code into his aircraft, and freely flying around enemy controlled airspace, and shooting at unsuspecting aircraft that view it as a friendly, due to the IFF return.

Basically it would open a can of worms re dishonest usage that would cause chaos on multiplayer servers. Anything that attempts to prevent this, would by its nature, be fudging how IFF works.

 

The issue you mention regarding inputting the opposing teams IFF codes is a non-issue, as it is fully realistic. No pilot should be flying with Mode 1, 2, 3/C or any other unencrypted transponder mode when entering combat. That's why Mode 4 and similar systems were developed who give encrypted responses and only respond if provided with the correct key, to avoid responding to hostile interrogations. Simply give both teams different encryption keys and the problem is solved. However, Mode 1, 2 and 3/C is still used by the military and it is impossible to fly according to real world procedures and tactics without these modes, hence why they should really be implemented into DCS Core, and not just for certain third-party aircraft.

[pabletesoy]

Well, we have someone who wants to make a proper IFF.

 

 

[Raven (Elysian Angel)]

It's not unheard of for a 3rd party to develop something that makes it into DCS's core - if Heatblur can do it with RWR libraries then RAZBAM should be able/allowed to for IFF