New PTP Link

Products PTP
#1

Team,

We successfully established 5 pair of PTP 650 in our customer and all are working fine. Now recently we established a new PTP Link with PTP650 the hop distance is 31 km. We faced the following problem.

1. Receive power is -71dB but as per the link planner it is -55dB (we cannot get after -71dB), 29 dbi Dish Antenna we used.

2. There are high interference in Master side which is -60dBm (45Mhz).

3. Also we cannot get the path as per the link planner which is 138dB. We got 152dB.

Is there any possible to increase the throughput?

Can i use highter gain Antenna ? or Increase the tower height?

Also i attached link planner and field diags file, please help me for best solution.

With Regards,

K.Esakki

#2

Hi,

Sorry I cannot attach files.

K.Esakki

#3

Hi,

To get higher throughput you have to get high modulation level  (higher SNR), and as you mentiond it is a very noisy environment.

Did you try different frequency bands as PTP650 supports multiband operating frequencies.

If the path is clear, you do not have to increase the hight of the tower but you have to linkplanner it.

If you are not allowed to use any other frequency band, I think you have to use HP dishes.

If the master side is a hub point (alot of deployed PTP links), I think you have to study using the PTP SYNC box.

Thanks.

#4

Recomendations:

1.- link planner is very accurate. I think you should try more alingment.(what brand of antennas are you using?)

2.- check pigtails.

3.- try alingment with 20 Mhz channel

#5

Hi Juan,

Thanks  for your reply.

Herewith i attach a screen shot, There is on error shows, can you please tell me what is that means?.

Regards,

K.Esakki

#6

Hi,

The message tells that you have to increase the heights till the Fresnel zone is totally cleared.

#7

Hi Esakki,

As Mohammed has said the message means that you don't have sufficient antenna height clearance to always clear the worst earth curvature, which means that the link will not achieve high availability. This also means that there is not much clearance for LOS, so as you are 16 dB lower in receive power than predicted, there is a likelihood that the path is obstructed.

If you would like to send your LINKPlanner project file to the LINKPlanner email address (linkplanner.ptp@cambiumnetworks.com) we can take a more detailed look.

Regards,

Rachel

#8

Hi Rachel,

Thanks for your update, i sent the LP file to you mentioned mail id.

Please take look and update your suggestion.

Regards,

K.Esakki