Join_Device Compatibility - GSM LTE

Linus Lu Updated by Linus Lu Permissioned article This article is internal and cannot be seen by public viewers.

The GSM LTE network offers compatibility with basically all 4G LTE devices. Even phones not intended for the US market will at least have compatibility for talk and text over 2G, which is still compatible with T-Mobile as of now.

Device compatibility can be checked using the new admin tool: 
You can also visit GSM Arena or will my phone work to check device compatibility according to its brand and model - Do NOT share these links with customers

To check a customer's device for compatibility with GSM LTE:

  • Ask the customer "May I please confirm the IMEI of your device along with the make and model, so I can look into it for you?"     

- When you search for the IMEI here. It will show the PSS a list of details. To check compatibility, PSS has to scroll down and check if the phone is T-mobile approved. If yes, scroll down and check the row labelled "Bands". It will show the PSS a list of bands the phone has, the PSS has to check for the GSM 1900, LTE Band 4, LTE Band 12 to verify if the phone will be compatible with T-mobiles network.

Phones with multiple sub-models/variants: Many phones have multiple variants. For example, the Samsung Galaxy S8 has a bunch of different carrier and region specific variants, with varying support for all the cellular frequencies out there (The G950U is the USA unlocked variant, and the G950T is the T-Mobile variant). Similarly, iPhones have different variants notably the The iPhone 7 A1660 (USA Variant, which works with both T-mobile and Verizon) and the iPhone 7 A1778 (Only compatible with T-mobile and note Verizon)


  • Device must have a SIM slot
  • It must be SIM unlocked, meaning able to accept another provider’s SIM card. For example, phones locked by carriers will not work with a US Mobile sim card
  • Device must not have its GSM capabilities restricted. Some Verizon/Sprint phones have a SIM slot and GSM radio but are not GSM unlocked, like the Casio G'zOne Ravine 2
  • Device must support the frequencies the GSM network uses (check below).

Most widely used bands and frequencies 


Frequencies that can provide 3G: Band 4 (1700/2100 MHz) and Band 2 (1900 MHz)

Voice and data services can work at the same time. You can use data while on a call.

Symbol Standard

Full Name

Maximum Download Speed

Maximum Upload Speed



Universal Mobile Telecommunication System

384 Kbits/s - 128 Kbits/s



High Speed Data Access System

7.2 Mbits/s - 3.6 Mbits/s



Evolved High Speed Packet Access -Release 10

168.8 Mbits/s - 23.0 Mbits/s


Frequencies that can provide 2G: Band 2 (1900 MHz)

Voice and data services don't work at the same time when on 2G. You cannot use data while on a call.

Symbol Standard

Full Name

Maximum Download Speed

Maximum Upload Speed



Global System for Mobile Communications

14.4 Kbits/s - 14.4 Kbits/s



General Pocket Radio Service

53.6 Kbits/s - 26.8 Kbits/s



Enhanced Data rates for GSM Evolution

217.6 Kbits/s - 108.8 Kbits/s


Frequencies that can provide LTE:

Band 2 (1900 MHz)

Band 5 (850 MHz)

Band 4 (1700/2100 MHz)

Band 12 (700 MHz)

Band 66 (Extension of band 4 on 1700/2100 MHz).

Symbol Standard

Full Name

Maximum Download Speed

Maximum Upload Speed



Long Term Evolution

100 Mbits/s - 50 Mbits/s



Long Term Evolution-Advanced

1 Gbits/s - 500 Mbits/s


Frequencies that can provide 5G:

Band n71 (600 MHz)

Band n41 (2.5 GHz)

Band n260 (39 GHz)

Band n261 (28 GHz)

One of the ways T-Mobile is rapidly deploying 5G is integrating mid-band 2.5 GHz spectrum from Sprint

For 5G, first confirm whether the customer has coverage in his area from this map



For basic talk and text, the phone must at least have Band 2 (1900 Mhz) for GSM. Note that GSM, when used to describe a phone’s cellular technology, means 2G.

Example: The Blu Joy shows GSM 850/900/1800/1900. This means it is compatible with carriers that use any of these 4 frequencies to provide 2G services. Since we offer 2G service on Band 2 (1900 Mhz), the Blu Joy is compatible with GSM LTE for talk and text functions.

ExampleBlu R1 Plus Has compatibility with GSM Band 2 (1900 Mhz), both 3G frequencies Band 2 (1900 Mhz) and Band 4 (1700/2100 Mhz), and the three main LTE bands 2 (1900), 4 (1700/2100) and 12 (700) -> So this phone will use LTE for data, 3G for talk, text and simultaneous voice and data, and 2G for talk, text and Edge data if neither 3G or LTE are available. If only 2G and LTE are available, it will use LTE for data, and automatically drop down to 2G for talk and text.


Our customers mostly tend to show up with Chinese kids smartwatches only offer 2G compatibility for talk, text and basic GPRS for tracking purposes. Some offer 3G and even LTE connectivity. To check specs, do a Google search for *watch name* specs. Amazon/eBay listings usually show the frequencies and carrier compatibility.

IOT devices

Alarm systems, GPS trackers, monitoring devices etc. Mostly have 2G compatibility only.

TK-102B GPS tracker

PSS can guide the customer to visit the IOT dedicated US Mobile webpage


We do NOT offer NB-IoT or CAT-M

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