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-   -   Typhoon cannot talk to F-22 (https://www.pprune.org/military-aviation/508632-typhoon-cannot-talk-f-22-a.html)

ricardian 22nd Feb 2013 19:52

Typhoon cannot talk to F-22
 
Top U.S. Stealth Jet Has to Talk to Allied Planes Over Unsecured Radio

Courtney Mil 22nd Feb 2013 19:57

It's an old argument. Link was never a "receive only" option. You have to ransmit to be part of the net. I recall our bomber boys wanting the same thing - so they could get an air picture without emmisions. You can't be positioned in a grid if you're not part of it. Now look what's happened.

BEagle 22nd Feb 2013 20:15


Link was never a "receive only" option.
Uh... excuse me, Mr. Courtney? That's not entirely accurate....:uhoh:

Lima Juliet 22nd Feb 2013 20:31

Courtney, ditto BEagle - receive only link is entirely possible.

Canadian Break 22nd Feb 2013 21:26

link
 
Thought you had to transmit the round trip timing message (M1/81?) on L11 and transmit to gain fine sync on L16.

Easy Street 22nd Feb 2013 22:15


You can't be positioned in a grid if you're not part of it.
My understanding was that if you're not contributing to the net, the kit doesn't need to transmit because it doesn't need to register itself to establish a transmission slot. It just listens to everyone else's messages?

kbrockman 22nd Feb 2013 22:42


My understanding was that if you're not contributing to the net, the kit doesn't need to transmit because it doesn't need to register itself to establish a transmission slot. It just listens to everyone else's messages?
I think it works a bit like this, every unit estimates its own TQ (Time quality), based on the clock drift, past accuracy of determining NTR (Network Time Reference) which it can do during the time-refinement time in every time slot ,and finally how long ago it did an RTT-exchange.
If any of these three parameters increases the TQ goes down, below a certain TQ threshold or after a certain pre-set amount of timeslots has passed,every unit needs to an RTT exchange which means 2 way communication by definition, so all in all there will inevitably be 2 way (sending/receiving) moments for everyone that uses Link-16.

Could be wrong though, but that's basically how I remember it.

orca 23rd Feb 2013 00:17

You can most certainly be in the link on receive only. I know a chap, let's call him my brother, who did exactly that just the oher day.

kbrockman 23rd Feb 2013 00:38


You can most certainly be in the link on receive only. I know a chap, let's call him my brother, who did exactly that just the oher day.
That might be true but after a certain amount of time slots , every Link-16 unit does an automatic RTT, it's nor nearly as big as the actual DATA transfer blocks but it's there nonetheless and it's by nature 2 way communication.

As far as only using it as a receiver, I don't know how long it takes for the TQ to degrade for every different system and how much info you can receive comparing the different methods of data-packaging (standard double pulse -> 4 single pulse).

althenick 23rd Feb 2013 01:02

I've never realy understood the Yanks myself. I thought it was iust me. Nice to know i'm not alone...

Bevo 23rd Feb 2013 01:10

There are solutions in work:


The U.S. Air Force says it has successfully tested a classified information transmission technology from two F-22 Raptor 5th generation fighter aircraft to ground stations at the recent Joint Expeditionary Force Experiment (JEFX 08) exercise at Nellis Air Force Base in Nevada and Langley Air Force Base in Virginia with new tactical targeting network technology under development by Rockwell Collins. …….

During the exercise, two Lockheed Martin F-22 Raptors tested a new method for universal F-22 connectivity with an experimental version of the Rockwell Collins' Tactical Targeting Network Technology (TTNT). For the first time F-22 sensor data was down-linked to the Combined Air Operations Center (CAOC) using a tactical network. In a previous test performed as part of JFEX08-2 earlier this year, images were transmitted from an F-22 to an F-16 via a ground based gateway. Through this experiment, the new radio successfully sent classified sensor data to ground stations at Nellis and Langley Air Force Bases, which then relayed the data to airborne F-16s. According to Col. Moulton, the test provided essential support for further development of future. Battlefield Airborne Communications Node ( BACN) assets and a future ground mobile gateway are designed to support joint air and ground operations.
LINK


Justanopinion 23rd Feb 2013 04:00


That might be true but after a certain amount of time slots , every Link-16 unit does an automatic RTT, it's nor nearly as big as the actual DATA transfer blocks but it's there nonetheless and it's by nature 2 way communication.
Can be done
actively = 2 way communication or
passively = not two way communication.

jwcook 23rd Feb 2013 04:44

Topic title is wrong - The F-22 can't talk to the Typhoon

dervish 23rd Feb 2013 05:49

IIRC this general problem once resulted in the Italians complaining they couldn't speak to Nimrod. I'm not sure about today, but not so long ago it wasn't policy to have this degree of interoperability. Somewhere, someone will be saying "Not a story, because not a requirement."

jwcook 23rd Feb 2013 05:55

To be fair no one speaks to Nimrod today.:*

BEagle 23rd Feb 2013 07:19


Could be wrong though, but that's basically how I remember it.
You describe active fine synchronisation with transmissions enabled.

However, coarse synchronisation also permits data to be received, provided that the user is on the right net with the correct cryptovariables. Transmission is not possible in coarse synchronisation.

If PPLIs are received, fine synchronisation can still be obtained using passive synchronisation; the JU will then be able to contribute in its assigned time slot as soon as the transceiver is switched to active mode.

Link16 is pretty amazing. I recall flying a VC10K3 back across the UK from a North Sea towline 13 years ago with the L16 in receive only mode - and still seeing F3s reported by an E-3D over Cumbria. We didn't lose the SRAP until we were on the final approach at Brize!

Transmitting on the ground certainly used to be prohibited. But fighter crews sitting on high readiness states whilst on exercise could get a lot of SA by using the SRAP to view the antics of their colleagues!

Lima Juliet 23rd Feb 2013 08:49

BEags - spot on mate.

By the way...


Transmitting on the ground certainly used to be prohibited
No one ever told me that! :p

LJ

ORAC 23rd Feb 2013 08:49

F-22 has a directional datalink, IFDL, to exchange formation between formation elements. It is not compatible with other data links. It was intended to upgrade the F-22 to be compatible with other platforms, that hasn't been funded.

The F-35 will have a similar directional datalink, MADL, to exchange formation data, which is not L16 compatible.

The only way to integrate these platforms with existing L11/L16/MIDS/L22 platforms is through an ACN/ BACN

In future the F-35 will use SATCOM to link through ground relays to transmit and receive data to be shared with non-stealthy platforms, but that has slipped to the Block 4 software build, and does require a view of a satellite, which is a major concern in the higher latitudes for both Canada and Norway.

Don't have a BACN or a SATCOM system? Too bad........

Lima Juliet 23rd Feb 2013 08:51

PS - If I recall correctly there was a silent mode that threw up a SIL caption on the JTIDS Control Panel. There was no transmitting going on but I would certainly get the picture.

Lima Juliet 23rd Feb 2013 08:53

BACN is a cracking piece of kit. I used it a lot in Afghanistan. It used the Global Express as a platform - now there's simething useful we can do with Sentinel!

The first time I used it, it was flying on a WB-57 Canberra!

LJ


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