When it comes to the difference between cellular modems, cellular routers, and cellular gateways, people could be very confused about it, so it is necessary to clarify the difference, which will help you to clearly understand the device functionality of modems, routers, and gateways. It could be very helpful when you try to select cellular communication hardware for industrial cellular applications. This article will focus on what is cellular modems, what is cellular router and what is cellular gateway, and when to choose which.
What Is a Cellular Modem
The cellular modem provides connectivity across a broad range of M2M and IoT applications. They allow Internet connectivity via serial port to PLCs, Meters, Vending Machines, so sometimes it could be called a serial-to-cellular converter. A cellular modem is not intelligent and not programmable, it simply sends traffic from one point to the other point, it usually doesn’t provide too much data protection, and it won’t have a firewall function. In some industrial IoT applications, cellular modems help to transport data from industrial serial devices to data control servers, allowing businesses to benefit from real-time data monitoring, management, and control.
What is a Cellular Router
A cellular router usually is a highly intelligent device, Every cellular router actually contains a cellular modem. A cellular router offers features such as Ethernet, Wi-Fi, serial ports, VPN security, dynamic routing, and link back up, providing reliable connectivity and business continuity solutions. Besides, a cellular router also provides a robust firewall so that it can handle packet-level traffic inspection, reconciling incoming traffic with outgoing requests. It should also support numerous types of tunnel options for data security such as IPsec, OpenVPN, L2TP, PPTP, GRE, and even DMVPN. The most industrial cellular router will have an I/O option, which enables users to handle some alarm tasks. Let’s take an example, you are monitoring the temperature of a particular asset which has been deployed in the field, perhaps it’s a pump, when the temperature goes too high or too low, exceeding the threshold that you set in advance, using the I/O, it will trigger an alarm system.
What is a Cellular Gateway
The cellular gateway typically acts as a translator for field devices, for example, a gateway could gather data from the field devices via different protocols and convert that data into IP protocol and send it via the cellular network. Gateways don’t have too many advanced networks features that routers do. Many industrial cellular gateways often offer users a secondary developing platform like python or other code languages, and the I/O is a necessary feature for a gateway.
For industrial IoT applications, a cellular gateway usually works with an IoT cloud like Azure or AWS, it helps businesses to provide a complete solution, data collection from the field device, and send it to a cloud for further analysis.
A cellular modem is very simple, it just transparently transmits data from a serial device to a data center, it usually has AT commands feature. A cellular router focus on advanced networking functionality and data security. The last cellular gateway usually connects to a network it has a very different purpose than a cellular router, it works as a converter, converts data from one protocol to another one, the most important function of a cellular gateway is protocol translation.