Can I use 4G SIM card in 5G SIM Router?

5G SIM router, or 5G CPE is becoming a popular solution of providing broadband network for home, small offices and commercial places. The solution is often called FWA (Fixed Wireless Access) services by telecom service providers and equipment manufacturers. As an alternative to traditional fixed access technology represented by fiber internet, it provides the same WIFI, Ethernet LAN and voice services with comparable internet speed, while relieving the trouble of laying fibers.

5G SIM router requires a SIM card to provide internet service. Some people are wondering whether they can use 4G SIM card in 5G SIM router. The answer is yes. Almost all 5G CPE in the market support 4G, and many also supports 3G. Here is an example of Hocell 5G CPE M110. The CPE supports one SIM card. Depending on the actual cellular signal it is receiving, it will light the LED of 5G or 4G. If the SIM card you are using is with 4G data package only, the CPE will just work with 4G network and the 4G LED would be on.  

If you look at the 5G modem chipsets in the market, whether it is Qualcomm, MediaTek, UNISOC or Huawei, all of them support 5G and 4G network standard simultaneously. And naturally, almost all the devices including 5G routers and smart phones support both 5G and 4G. However, one thing should always be kept in mind, that is, you need to check whether the devices support the frequency bands of the 5G/4G networks available where you are going to use the devices. A device supporting 5G and 4G not necessarily mean it works with the networks in your region, country, or the telecom service provider that you have chosen. If you take a look at the 5G & 4G frequency bands defined by 3GPP (International Standard Organization for Telecommunication), you will find that there are a variety of 5G and 4G frequency bands adopted by different countries and telecoms. It’s nearly impossible for a device to support all the bands.