Re: PTP800 11GHz Link Drop

Products PTP
1

How long are these up/down alerts? Any drop in modulation mode on the status page? What is the vector error variation in dB?

2

This is a snippet of the syslog page, from start to finish of an "event:"

37116 00:35:23 Mar 13 15:23:32 Local 5 Warning status; Wireless Link Status; was=Down; now=Up;
37115 00:35:23 Mar 13 15:23:32 Local 5 Warning status; End Wireless Receive Signal Status; was=Not Detected; now=OK;
37114 00:35:23 Mar 13 15:23:32 Local 5 Warning status; Wireless Receive Signal Status; was=Not Detected; now=OK;
37113 00:35:26 Mar 13 15:23:27 Local 5 Warning status; End Wireless Receive Signal Status; was=OK; now=Not Detected;
37112 00:35:27 Mar 13 15:23:27 Local 5 Warning status; Wireless Receive Signal Status; was=OK; now=Not Detected;
37111 00:35:27 Mar 13 15:23:27 Local 5 Warning status; End Wireless Receive Signal Status; was=Not Detected; now=OK;
37110 00:35:27 Mar 13 15:23:27 Local 5 Warning status; Wireless Receive Signal Status; was=Not Detected; now=OK;
37109 00:35:27 Mar 13 15:23:27 Local 5 Warning status; End Wireless Receive Signal Status; was=OK; now=Not Detected;
37108 00:35:27 Mar 13 15:23:27 Local 5 Warning status; Wireless Receive Signal Status; was=OK; now=Not Detected;
37107 00:35:28 Mar 13 15:23:27 Local 5 Warning status; End Wireless Receive Signal Status; was=Not Detected; now=OK;
37106 00:35:28 Mar 13 15:23:27 Local 5 Warning status; Wireless Receive Signal Status; was=Not Detected; now=OK;
37105 00:35:28 Mar 13 15:23:27 Local 5 Warning status; Wireless Link Status; was=Up; now=Down;
37104 00:35:28 Mar 13 15:23:27 Local 5 Warning status; End Wireless Receive Signal Status; was=OK; now=Not Detected;
37103 00:35:28 Mar 13 15:23:27 Local 5 Warning status; Wireless Receive Signal Status; was=OK; now=Not Detected;
3

Inferring from the RX Data diag plotter, I can see that the rate doesn't go straight to the floor, but the drop and recconnect is so fast that it's hard to catch it in action. VectorError and RX Data graphs are attached.

Vector Error usually varies no more than +-5db unless we have rain/fog fade.

4

How long is this path? What were the weather conditions during the wireless link in and out?

5

The path is about 10 miles. Weather does affect the path as expected, but this particular issue is being seen during clear weather.

6

I would ask to check out the Link Loss plot as well to see if it coincides with Vector Error and Rx Power plots. If link loss is also impacted then I suggest checking out the physical condition of the antennas, is there a slight sway? Is there possible obstructions like trees? What is condition of the IF cable? Is the path over water?

The following step would be to check for RF interference and  perform this by shutting one end of the link, given that you still have remote access to mute/unmute the TX power are remote end, monitor for possible Rx power levels on the local end.

Thermal ducting can also impact a link.

7

Link Loss does show vlaues clear up to 220 durring the latest event.

I'll have someone check the antennas out. There is a small 0.5mi lake about 2.5mi along the path. I'll send you the link planner project off-list.

8

We had to wait till last night to take the link out of service. We muted the transmitter and captured the vector error and rx power. I checked the rx power csv and saw that both sides never came up from -90.

9

I recommend to inspecting the antenna mounting situation as well verify the LOS path situation.

10

I can see that the rate doesn't go straight to the floor, but the drop and recconnect is so fast that it's hard to catch it in action.

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