This guide shows how to connect a RelaxedSIM USA prepaid data SIM in a Netgear MR6400 4G router, including the fix we used to get a real customer’s Emlid GNSS receiver online in the field. Two settings matter most: enter the APN globaldata and turn Data Roaming ON. Everything else below is troubleshooting for when those two are already correct.
Quick answer for Netgear MR6400 + RelaxedSIM USA SIM
- APN: create a profile with
globaldataand leave the username and password blank. - Data Roaming: turn it ON in the router settings.
- Networks: the SIM connects on AT&T, T-Mobile, or Verizon with no activation, no contract, and no carrier lock.
Step-by-step: set up RelaxedSIM on the Netgear MR6400
- Insert the RelaxedSIM SIM (Nano size from the 3-in-1 card) into the MR6400 and power it on.
- Open the router admin page, usually
192.168.1.1. - Go to Settings → APN.
- Add a new APN profile:
- APN:
globaldata - Username: leave blank
- Password: leave blank
- APN:
- Save the profile and set it as Active.
- Turn Data Roaming ON in the router’s mobile settings.
- Reboot the router and wait up to one minute for the connection.
Why data roaming must be ON for a USA data SIM
RelaxedSIM SIMs are data-only and roam between the AT&T, T-Mobile, and Verizon networks to pick the strongest signal. Even inside the USA, many routers treat this as a data connection that requires roaming to be enabled. If roaming is off, the MR6400 may show a registered signal while no data passes through — the most common issue in support tickets.
Still no internet? Check these Netgear MR6400 settings
- APN Protocol (PDP type): if it is set to IPv4 only, change it to IPv4/IPv6 or IPv6.
- Authentication: use None, or PAP if your router requires a method. CHAP is not needed.
- Active profile: confirm the
globaldataprofile is selected, not an old carrier profile. - Reboot: restart the router and the connected GNSS/IoT device after changing settings.
RelaxedSIM USA data SIMs for Emlid GNSS and field work
The Netgear MR6400 gives your Emlid GNSS receiver internet over Ethernet or Wi-Fi for NTRIP correction streams and RTK workflows. A data-only SIM is the right choice: RelaxedSIM SIMs are pre-activated, work in unlocked routers and IoT devices, and every plan starts with a free 100MB/7-day trial so you can verify coverage at the job site before buying a larger plan. Full APN reference: RelaxedSIM APN details. Shop all plans: USA data SIM cards.
Frequently Asked Questions
What APN should I enter on the Netgear MR6400?
Enter globaldata with a blank username and password. Do not add a proxy or port.
Do I need to enable data roaming on a USA SIM?
Yes. Enable Data Roaming even inside the USA. The RelaxedSIM SIM connects through AT&T, T-Mobile, or Verizon, and without roaming enabled it can show a signal without passing data.
Should I use PAP or CHAP?
Use None first. If your router needs an authentication method, choose PAP. CHAP is not required for RelaxedSIM.
Which RelaxedSIM plan is best for Emlid GNSS / RTK work?
For Emlid GNSS and RTK testing we recommend the 3GB/30-day plan. NTRIP correction streams can use up the 100MB trial quickly, while 3GB gives enough headroom to test the full workflow in the field. The free 100MB/7-day trial is still applied first, so you can confirm coverage before the paid plan starts.
Will this SIM work in other routers or phones?
Yes, in any unlocked device with a physical SIM slot, including phones, hotspots, routers, security cameras, and IoT equipment. The SIM is data-only and does not support calls or SMS.