Is GPS Running

Fairly new to GPS on the 450i , Today I setup and turned on ugps how can I tell if everything is running as should/optimal? 

Which settings on the radio must match for UGPS to work ? Or any other tips/tricks

Attached is a photo of my sync tab and the config. I am unsure what sync output to aux port does or means.  Thanks in advance. 

GPS appears to be running well.  The sync signal is being received, and you're tracking 18 satellites (you need 4 minimum to get lock).

Sync output to AUX port means that you can have that unit act as a sync pulse repeater to another unit.  You won't likely be using it in this configuration.

Which settings on the radio tab and or other tabs need to match. I have everythign matching but the max distance to subs 

That Sync Status and Sync Configruation all look good.

 For co-locating 900MHz OFDM with 900MHz FSK, please check out this whitepaper, which goes into great detail about what should be considered and how to properly configure the systems.

For co-locating with other OFDM 900MHz devices, you can use common settings for Max Range, Duty Cycle, Frame Period, and Contention slots.  If you want to change any of those, you must use the Frame Calculator tool to make sure that the resulting frames are compatible.

If you want everything to match but max distance, that may be problematic, but the frame calculator will tell you what is compatible.  It can be daunting at first, but there are ways to have mismatched configurations still be frame compatible. 

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Are you asking which settings should be considered in order to ensure timing between sites will minimize interference?

If so, there's a great little excel tool here that can ensure you've got the parameters in line to make this work.

The parameters that need to be considered are: 

  • Channel Bandwidth 
  • Downlink Data (Duty Cycle)
  • Max Range
  • Contention Slots

And, of course, all the sectors within hearing distance need to be the same frame length (either 2.5 or 5 ms).

I see Aaron already replied... good thing we said nearly the same things. :)

Thank You. I have both aps set with the settings you mentioned above other than the max distance on one ap is set at 5 and another at 7. The excel files with my numbers in it came back Green OK so I am assuming that is fine. They both appear to be running very well using 7mhx channels . I rebooted the ap's last night and it took about 15 minutes for everything (clients) to start responding, I mean they were connected but the throughput was low almost like they were out of sync and then a couple minutes later they all started responding well. Is this expected behavior?

Thanks for the help/info

When you say "throughput was low", how were you measuring?

Upon startup, the radio will not raise its modulation until data starts being successfully passed through the link, so it may start slow, then ramp to it's maximum modulation.  This should happen very quickly, however, once data starts traversing the link (within seconds).

It shouldn't take 15 minutes typically.

Maybe I had a litte outside interference then when I was testing because it took a little time for it to go away. 


I used a straight cat5 cable from Aux port on 450 m to the center port on GPS module, Salesman states this should provide sync. It does not. Have autosync/free run set, have power enabled to aux port,

any clues?

we have had to cut cables half way and insert sync from adjacent ap's sync output. This could not be good in the event of lightning.

The center port of the UGPS is solely to provide Power to the UGPS device (and is highly recommended if you are using the UGPS to provide sync to two 450i radios (using the timing/AUX ports on either side of this center port).  

The center port is NOT used for sync in any way.

This is explained in the PMP Synchronization User Guide, which can be found on this page.

I am not sure I understand what you mean by having to "cut cables half way".  There are two sync ports on every UGPS.  The pinout for the cable needed to connect to a 450i or 450m AUX port can be found in the same User Guide, or in this post.

cutting the cables is to insert the GPS back into the AUX port of the radio,

there are only 3 ports on a 450M

1: power and data port

2: Aux power out port

3:SFP port (for data)

pinout shows gps in on ping 4578 of aux port,

so we have to come out of uGPS unit sync ports on side of uGPS, then splice into the aux power cable, sending sync from pins 1346 to 4578

And this is 450 Medusa not 450i

450i and 450m (450m = cnMedussa) are the same pinout for the AUX port.

The post I refer to above is the cable diagram to connect from the UGPS timing ports (the outside) to the AUX port on the 450m, and the pinouts you cite are in agreement with that.

Do you still have any questions outstanding that aren't covered here?