Issues connecting to Verizon network with HL7618RD and HL7588


We have a product we’ve developed in the UK that use the HL7692 modem, which we are very happy with.

Our partners in the US want to use our product, so initially together we selected the HL7618RD for Verizon and HL7688 for AT&T.

The HL7688 for AT&T works as expected (as per what we’re used to with the HL7692), however we’ve been having huge issues getting the HL7618RD to connect.

The HL7618RD, seems to sit in CEREG, CGREG, CREG state 0, occasionally going to state 2 to indicate that it is searching for a network to join then immediately going back to state 0 - Not Registered Not searching.
During this time the device does receive +XCESQI signal strength indicators.
We’ve left the device for a couple of hours, and seemingly it does eventually connect but then is unable to send and receive SMS. Our partners in America told us that Verizon is a bit peculiar when it comes to letting devices on their network and we found out that the HL7618RD isn’t on Verizons approved list of modems.

We then bought a HL7588 to try, as this modem is on Verizons list of approved modem, and are still having issues.
This modem does connect to the Verizon network - CEREG and CGREG are reporting state 1 (Registered), however CREG is reporting state 3 (Registration Denied). COPS was reporting that it was registered on Verizon and state 7 (LTE), and the device was receiving +XCESQI signal strength indicators

We’re unable to send SMS from the device, or receive SMS - no CMTI indications were received even though the device is setup to receive these. Nor were our partners able to call the device, it went straight to voicemail.
We wondered if our partner was using a Data only Verizon SIM, but i’ve been informed that they’ve tried the SIM in a phone and were able to SMS & call.

I check to see if the modem had a Message Centre set and had the following response
+CSCA: “+19037029920”,145

I’m unsure of the PDP contexts mentioned in the AT Command Specification notes, but this was the response to a AT+CGACT? - which I think looks ok?
+CGACT: 1,1
+CGACT: 2,0
+CGACT: 3,0
+CGACT: 4,0

I would appreciate any assistance with this, whilst we can potentially move forward with the AT&T solution, we would like to offer a Verizon option also, and i’m a little bit stuck as to where to go from here.


Hi Liam,

Some suggestion for you, hope it help:

  • Upgrade the latest FW HL7618RD VZW Firmware V1.10
  • Try to use a high gain antenna, and connect both main and diversity antenna.
  • Note that Verizon supports B2, B4 & B13, HL7618RD supports B4 & B13 only.
  • Check the following results:
    at+xireg? //IMS registration status
  • HL7618RD should suppport SMS MO/MT.


Thank you for the suggestions, i’m looking back at some of the previous logs I took:
The response to AT+CGMR to get the firmware version was:

I believe this indicates the firmware version is 1.6.15. We don’t currently have a way to upgrade to 1.10 via the device (no USB connection). Is there another way we can do it? We have a Mango-RED dev kit here in the UK, but our partners overseas won’t have this.

The response from AT+CGDCONT?
+CGDCONT: 1,“IPV4V6”,“VZWIMS”,"",0,0
+CGDCONT: 2,“IPV4V6”,“vzwadmin”,"",0,0,0,0,0,0
+CGDCONT: 3,“IPV4V6”,“VZWINTERNET”,"",0,0,0,0,0,0
+CGDCONT: 4,“IPV4V6”,“VZWAPP”,"",0,0,0,0,0,0

+CGACT: 1,0
+CGACT: 2,0
+CGACT: 3,0
+CGACT: 4,0

But I can’t be sure if this was from debugging the HL7588 or the HL7618RD.

We will look at trying high gain antennas on both main and diversity connections and look at trying to get the responses you’ve requested.



We are dealing with the same problem. Did this issue solve?
The difference is that we are trying to certificate our product at Verizon network. For this, we want to change the CGDCONT. Basically the PDP 1 have to be VZWINTERNET. Currently is not possible to change that.

Hi Rafael,

Sorry, no, we gave up with that modem and ended up using the AT&T modem, which worked perfectly.

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So funny is one way to describe Verizon I guess. Essentially unless you have approved your application on their network which then also secures your line of getting Verizon SIM’s then you will not be able to attach. Just using an approved modem (which the HL7618 and HL7618RD are) will not allow you to attach and use the network as you would expect to be able to do in Europe, the networks are far more closed/controlled.

The Sierra units that are Verizon approved come in the configuration as required by Verizon and no other config will work. AT&T and TMO are easier to work with typically speaking.

Using Verizon is a big commitment in terms of time and cost and you need to look at it very carefully as it is the hardest to pass as well. We do discuss this in the NA approvals apps note. Unfortunately there isn’t an easy way around this.



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Useful info, thanks Matt.
Our Market and the numbers we shipped to the states were way less than even the developmental units for the Verizon process. It simply wasn’t worth the effort.

But useful information for the future and anyone else viewing. Thanks

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rafael, why were you changing the slot 1 details for your testing, was this requested by the test lab?

We are going through certification now with a HL7588 enabled device and the test lab is saying we can’t set anything, it has to be retrieved by the module from the network, but the modulenis not retrieving anything when we check it seems.

Did setting the details at context 1 allow you to pass?

I wanted to change because the test lab was requesting.

Did setting the details at context 1 allow you to pass?

After the first interaction here, I had the help of a colleague of mine, he started to deal with the certification and he took care of everything. He is on vacations and I can ask him about the process when he return

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