Hi Everyone, looking for any input on a problem we’re having with our MAX-BR1 devices and band selection.
We’re constantly seeing devices via the InControl WAN quality reports that will have a great -90dBm signal on say band-12 700MHZ and then switch to say band-2 1900MHZ and have -115dBm or worse signal. I know we can go in and deselect the poor performing band and have started doing that but can be very difficult to do via Remote Web Admin while connected on the poor performing band.
This seems to be occurring often with firmware 8.3 and when rolling back to 8.2 seems to happen less. Seeing this issue on all versions of MAX-BR1 minis.
Manually updating the cellular module firmware to latest via the support.cgi doesn’t seem to make any difference.
Happening on both Verizon and ATT carriers in the US.
I’m not sure if the band selection is being made for speed versus signal strength or maybe tower capacity?
My understanding was that the Pepwave will tell the tower what bands it supports and then the tower will tell the Pepwave which band to use so when disabling the poor performing band it’s no longer advertised to the tower as being available.
I’d appreciate any information on how the band selection works what we can do if anything other than disable poor bands.
I’ll let others respond to your principal question but I’ll point out that a signal of -90dBm is not a good signal at all. While RSSI is a very poor measure of LTE/5G performance, it is of some value. Here’re the parameters to which we should be paying attention:
I’d argue that if only a single parameter can be relied upon SINR is probably the most important – signal to noise ratio.
In the case of poor signal metrics the first question would be related to the positioning/location of the router and the second would be the type of antenna(s) in use.
Here’s an example of what we’re seeing daily many devices.
Device is on band-12 700MHZ at -81 RSRP and then switches to band-2 1900MHZ at -102 RSRP
Maybe it’s because the 1900MHZ had better latency?
Right. My assumption when you referred to “signal” you were talking about RSSI – which is not good at all. If, in fact, you refer to RSRP, I’d say it’s “OK.” And, yes, your table is fine – there are a zillion of these floating around the internet and they generally pretty much agree. But regardless, I’d want to know more about the SINR. We have seen oh-so-many cases where RSSI and RSRP were nice but SINR was crap. In such cases guess how the units performed … ;<)
Got it, do you know where I can find the SINR values?
I know it was shown in InControl with the 3G MAX-BR1 units but can’t find it anywhere for the LTE units?
Looked in the hidden and expanded the engineering fields.
I’d sure help if I could but I don’t have access to any BR1 Mini LTEs on-line at the moment. (Maybe someone else can assist?) I’ll mention that there are a few modems that do not report SINR and in such a case Peplink’s FW can’t show it.
In my experience it varies w.r.t. whether SINR is reported across all the bands selected or only the primary one.
Communication quality v. signal quality may be correlated, but it may not carry from one band to another. E.g., in one of our locations Band 12 looks really good and Band 4 looks really bad, and yet connections using Band 4 are much better in practice than those using Band 12.
My understanding is that the service provider ultimately decides which bands to employ: The modem offers up a menu of bands (that’s what you can determine on the Peplink router), then the provider decides which of these to employ for a particular connection.
Hi zegar_mjol,
Thanks for confirming that SINR is still displayed in IC2
After seeing this I dug deeper and appears that SINR isn’t displayed for our devices with the Telit LE910-NA V2 modem which if you saw my other post appears to be the common denominator with our Pepwave devices randomly going offline and needing to be rebooted. Checked devices with both ATT and Verizon as the carrier.
Band selection is determined by the tower - and in my experience the carriers seem to optimize for tower capacity concerns more than signal strength, end-user reliability, or performance.
This is why manual band selection is so powerful - it lets you keep the tower from shuffling you to a weaker / slower band.
This is particularly important when you want to optimize for better upload performance - because the tower rarely seems to make upload speeds a priority when assigning bands.
