Order of precidence - PAW and ADSB

[gilest]

I was wondering what the precedence between ADSB and PAW. If an aircraft is transmitting both ADSB and P3I which will be displayed in the traffic log of the PAW.

I assume P3I takes precedence over Mode S!! Hope so!

Purely for interest and to help build the community it would be great to have some audible distinction between P3I and ADSB alerts. Maybe simply appending the word PAW to the P3I transmissions.

[exfirepro]

Giles,

In very basic terms, if more than one signal is received carrying the same ICAO 'Hex' address the content is compared and the lower priority (in information terms) signal is filtered so you don't get two or more reports of the same aircraft. Hence ADSB and P3i are both higher priority than Mode S because of their GPS derived positional information.

Because ADSB and P3i in effect both provide the same information, they are displayed and reported on using the same positional triggers and terminology. The only reason Mode S is reported differently is because we have no positional or directional information to report.

If it's important, you can tell the difference by reference to the traffic screen: Basically, entries having a DISTance in KMs and a defined SIGnal strength are ADSB, those with a DISTance and SIG = 0 are P3i. Mode S have ' - ' in the distance column.

Whilst I can appreciate that it is 'nice to know', I'm not sure the extra work required to create 'different' audio alerts for ADSB and P3i would be beneficial (or indeed desirable) in the longer term and could lead to additional confusion.

Only my opinion

Regards

Peter

[Admin]

Hi Giles

Whilst I can appreciate that it is 'nice to know', I'm not sure the extra work required to create 'different' audio alerts for ADSB and P3i would be beneficial (or indeed desirable) in the longer term and could lead to additional confusion.

I have to agree with Peter here, we have tried to make the audio alerts as concise as possible, I am not sure that adding information regarding P3I/ADS-B is of any real benefit TBH, could you let us know why you think this is the case ?

Thx
Lee

[gilest]

Peter

Thank you. My reason for asking about the precidence was that I was starting to wonder if P3I transmissions were being masked by ADSB or mode S as in many hours of flying with the PAW I have not seen another P3I transmission.

I appreciate that broadly the same information is transmitted on P3I and ADSB, so there is no need to differentiate between them for traffic avoidance purposes - but for the purpose of building the community and "getting the word out" that for a pilot to be able to see that another aircraft just landed or on the radio is using PAW that it may go some way to getting more devices in the air. My assumption was that by appending a short word at the end of the (rare) P3I alerts would both not distract and would be technically fairly simple. But probably wrong!

The question about precedence was more interest than anything. So if an aircraft is transmitting both ADSB and P3I I assume from your answer that the distance and signal with display a non zero figure - so in effect ADSB takes precedence over P3I?

[Admin]

One thing to note, if you have NOT changed your default GroupID from PAWGRP, then any other P3I transmissions in the same group will appear bracketed by hashes on the display, ie,

#G-PAWZ#

Thx
Lee

[exfirepro]

Giles,

I have only seen one other 'definite' PAW up here in Scotland so far - and that was my mate AlanG when we have been testing - and even then we had to turn ADSB off to make sure we were seeing each other's P3i. Stick with it though, it is great when you can follow each other round - especially on cross-country fly-outs and know exactly where the other aircraft in your group are.

Regards

Peter