Recently got my base station up and running. Connected to rtk2go and confirmed it was receiving data. The packet size was in the same ballpark as other stations and the speed of the connection was good. My issue is that while rtk2go says that the amount of data my unit has sent to the site was ~50MB over about an hour, my cellular router says that the IP address/MAC associated with my station sent over 1GB of data! I was under the impression that base stations were fairly low on the bandwidth demand. What could be the issue here? Since it runs on cellular I have a fix amount of data per time cycle (usually 12GB/year, but more can be added). All of the other IoT devices used a total of 3 GB over the last year. Thank you in advance for your help!
So not clear from your presentation exactly what you’re sending and how its configured.
At a guess you’re pushing a full NMEA stream over the connection or have a high solution rate.
Connect via a terminal, check what’s actually coming out.
^Like Clive mentioned; share your settings (screenshots work well!)
The RTCM3 packets are binary, there should be negligible human read-able text, but if you have NMEA data it will be a lot of ASCII characters, and multiple sentences with commas and numbers, which you can read.
Here are some screenshots of the settings, data usage, rtk2go station info, and the base station local files created every day. In the 3min I had it casting to rtk2go (after initiation) it transmitted over 60MB (according to my router.
Hi @Westin_Morrill ,
That all looks great. Please check the “GNSS Configuration” tab and drop the Measurement Rate to 1Hz. It defaults to 4Hz. The NMEA and RTCM rates are set in measurements, rather than Hz.
Best wishes,
Paul
OK. Thanks for checking. Maybe your router is reporting Mbits, not MBytes?
It looks like you are logging about 180MB per day to SD card. Roughly 7.5MB per hour or 60Mb per hour… Roughly 2KB per second.
RTK Firmware V3.5 is fairly old. I’d start with updating the FW.
I wouldn’t consider a GNSS Base Station as a low-bandwidth device particularly well suited for Cellular operations, but I’d love to see you get this working in an acceptable manner 
Here are some suggestions to consider:
Turn off NMEA messages.
Turn off All RTCM, and focus on 1 constellation for initial Bandwidth Testing.
Be very stingy with what you turn on during the test.
For example, in the US - I’d start with only GPS and focus on MSM4.
That would be 1005 and 1074.
The initial goal is to prove that you’re not experiencing some crazy overhead in the Cellular Backhaul.
Now you have a decision to make: MSM4, MSM7, or Both.
Swap to MSM7 and notice the bandwidth difference.
It’s up to you to decide if the RTK performance benefits (MSM 4 vs 7) outweigh the bandwidth cost for your Station.
Now, you can decide which Constellations are worth the bandwidth.
For a Cellular Reference Station, anything you transmit needs to be beneficial. Don’t send it just because you can
If you want to take a shortcut, turn off NMEA and only send :
RTCM 1005, 1006, 1074, 1084, 1094, and 1230.
Hopefully you can handle the cellular data usage.
Because a GPS/GLONASS/Galileo Cellular Reference Station sending MSM4 is a Win to me.
So after adjusting the settings, I am only sending 1005 (1), 1074 (1), and 1230 (10), I still used about 900MB ina 23 hour period. Still too high for the amount I am willing to pay for cellular data. Any additional thoughts?
Also, rtk2go says the station only sent 7.81MB of data.
I’m also surprised by those results.
But you went from 1GB per hour to 1GB per day.
Any chance that you can spy on the traffic to/from your cellular router ?
Also: Your Base might be sending something else (Raw, unrelated to NTRIP, etc) over the port, even though rtk2go would simply parse the valid RTCM data.
You only need 1230 if using GLONASS as 1084/1087
Both 1005 and 1230 are constant and repetitive, so the periodicity can be backed off substantially. They aren’t particularly large.
One could also probably decimate the data requirements if it were throttled based on the fix-type one already had. RTK can be maintained for minutes if you’re not constantly obstructing signals or losing carrier lock.
I guess you could look at better cellular data plans (IoT rather than consumer), or determine the break-even of having your own localized infrastructure, be it WiFi, LoRa, or other short-range radio, or sharing of resources in a one-to-many rather than one-to-one transaction.
It’s one of the appeals of L-Band services
Also: Your Base might be sending something else..
The model for Point Perfect via the internet is now an NTRIP SPARTN-NEAR mount-point that’s not even RTCM3 data, but a location tailored feed, with significantly lowered band-width. Basically using the NMEA GGA to just feed the data from the GAD (Geographic Area) you’re in rather than the 30-40 covering the entire continent. You can still get the NTRIP US mount-point. They dropped my MQTT option, which is probably more bandwidth hungry, with the authenticated NTRIP connection, and now the SPARTN on the NTRIP feed is unencrypted, so likely also less burdensome on the key management side and decryption loading on the ZED-F9x
Yeah, that still seems an order of magnitude beyond what I’d expect.
At 1000 bytes/second you’d be at 86.4 MB
MByte not Mbit..
I’d wonder/worry about how much data you’re pushing back, NTRIP would only need a relatively low periodic NMEA GGA to establish location / keep-alive connection.