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Paper Tape
Posts: 1
Registered: ‎03-16-2017
Location: US
Views: 1,430
Message 1 of 2

Sierra Wireless EM7455 card will not connect to LTE

I have an X1 Yoga 20FQ with Windows 10 Enterprise 64-bit and a Sierra Wireless EM7455 WAN card that came with the unit from Lenovo and an AT&T micro SIM card (also in the unit when it came from Lenovo). I also have the latest Lenovo software for the Sierra Wireless card (v. 7.47.4743.0105) from the Lenovo web site. The WAN card will connect to HPSA on AT&T (using the "default APN" and "broadband" in the Win 10 settings) but it will not connect to AT&T LTE. The AT&T web site at!/wireless/KM1218316 says to use NXTGENPHONE as the APN, but when I input that as the APN the card does not see it at all. I know that NXTGENPHONE is the LTE APN because that is the APN that my cell phone uses for its LTE data connection. AT&T tech support told me I the Windows 10 and NXTGENPHONE APN settings are correct and the AT&T diagnostics show I an LTE connection is available to me.

I realize that there can be sources for this problem (Win 10 or AT&T) but I thought I would ask here to see whether anyone has experienced the problem or has a solution.


Community SeniorMod
Community SeniorMod
Posts: 11,853
Registered: ‎06-06-2011
Location: RU
Views: 1,380
Message 2 of 2

Re: Sierra Wireless EM7455 card will not connect to LTE

Welcome to the Community

Usually, the APN value might depend on the customer contract (tariff plan, SIM card type..) and mobile device type (smartphone, tablet, wwan modem...). I saw some APN values for At&T networks on the Internet - NXTGENPHONE (for the phones), broadband (seems for the modems), pta (not sure what is it for). Unproper APN might prevent to get some broadband services.

So, contact the operator's support team to clarify - what APN value is suitable for
a)your SIM card
b)LTE service access
c)wwan modem.

Let them (supporters) to check out your SIM card in their device with wwan modem (i.e.not in the phone, any LTE USB modem is needed) and test LTE service availability.

Sometimes just a new SIM card re-emission is enough to resolve issue.

Regarding your modem em7455.
The issue might be caused by its firmware, its actual version and cellular operator provisioning applying. The em7455 fw images set has a separate provisioning file for At&T, carrier approved. It might be not applyed by some reason, so the modem doesn't work properly. Check, at least, the modem's fw version. In order to check and change the rest modem options some efforts and skills are needed. Or you can use Sierra's application - Skylight Connection Manager, it has some useful features like modem control, network type selection etc.

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