WP7608-1 won't connect to callbox on 16 QAM for bandwidths 10,15, and 20

IoT Modules WP Series
1

Hello,

As stated in my title, I am working with three WP7608-1 modules, and while in the process of trying to connect them to an R&S CMW500 Callbox for certification testing, the team that has my modules hooked up says every time they try to perform a basic LTE RX Path test (as outlined in the Technical Reference Guide) using bands 1, 3, 5, and 8 on 16 QAM modulation with a bandwidth greater than 5Mhz, the transmission ends as immediately as it starts, with an “RCConnection Detach Request”, and in some cases, you can even see one wave pass on the callbox before the signal goes flat again.

I’ve tried just about every AT command in the reference sheet related to receiving on the radio and nothing has worked. I’ve tried disabling Legato apps and re-installing a stock firmware SPK… still nothing. I’ve also tried monitoring logread while they started their calls, but it doesn’t appear there is any error in logread to observe; or at least any obvious to me. (Also I am trying each device out individually on the box)

I’m starting to run out of ideas, and as far as I can see in the documentation there is no reason to believe the WP7608-1 doesn’t support these bands with this modulation and bandwidths. Does anyone have any idea what’s going on here? 1.4, 3, and 5Mhz 16QAM modulation work, but anything greater than that it’s just a flat line.

Any help would be greatly appreciated!

2

Hi @SteveDave,

Welcome to our community!

In this case, it’s better if you send an email to technical support at support@sierrawireless.com for further assistance.

Thanks,

3

Thought I’d reply on this old topic to let you know what the solution was:

WP7608-1 is a low bandwidth module, as designated by the “-1”. Therefore the module is not capable of using higher modulation bandwidths greater than 5Mhz.

This should have been obvious since the device is Cat1 and not Cat4, but the external team I was working with assumed it was a Cat4 version (WP7608). Anyway, once we realized the module we were testing was a low-bandwidth variant, we made corrections to our test setup, and were able to certify the module without anymore issue.