Cellular Standards – CompTIA A+ 220-1101 – 1.4

Our cellular networks have seen significant change, and improvements to voice and data access have continuously improved over time. In this video, you’ll learn about GSM, CDMA, 3G, 4G, and 5G technologies.


Many of the things we do in our normal workday involve using our mobile phones. These are our cell phones. And we call them cell phones because they are using a cellular network. We call it cellular because we are separating up the geography of an area into sections or cells. And we put antennas at the edges of those cells so that we’re able to maintain connectivity wherever we might happen to travel.

Some of the original cellular networks were called 2G networks. And they consisted of two global standards. One of these standards was GSM or the Global System for Mobile Communications. And the other one is CDMA or Code Division Multiple Access. Both of these standards were very good for voice communication, but they had very limited support for sending data over these wireless networks. They were originally circuit switched networks and really had to be upgraded to allow some type of data connectivity.

GSM was a big part of that very early cellular network. GSM being the Global System for Mobile Communications. GSM was about 90% of the worldwide market. It was a standard in the European Union and allowed you to have coverage wherever you happen to travel in the world. In the United States, common GSM networks were the AT&T network and T-Mobile network. This GSM network allowed you to have all of your phone configurations on a subscriber identity module or a SIM card. And you can move that card from phone to phone, and your phone number would follow you depending on where that SIM card happened to be.

This GSM standard used multiplexing to be able to have many people communicating at the same time over the same frequencies. Every user got a little slice of time and could send the information while other people were also conversing on that same network. This allowed people to perform voice communication, data communication, and combine all of that across many people in one single geographic area.

CDMA is the Code Division Multiple Access. And as the name implies, you can have multiple people communicating over this network. But as they were sending information, they were sending it with a particular code. Each call used a different code to be able to communicate, which meant that the handset that you were using could filter out codes that weren’t important to your conversation and focused only on the code specific between you and who you’re talking to. In the United States, CDMA was commonly used by Verizon and Sprint. They controlled exactly what handsets you were able to use on those networks. And unfortunately, CDMA wasn’t popular in other parts of the world or with other providers.

As more people needed additional capabilities on these mobile networks, we needed newer standards that provided additional features. One of these newer standards was the third generation or 3G technologies that we introduced in 1998. This allowed us to have much more capabilities for the data that we were sending from our mobile devices. And we had additional speed so we could send more of that data much faster over these same networks. Usually we got about several megabits per second of speed over the best possible 3G connectivity.

With these enhanced speeds, we were able to introduce new capabilities for our mobile handsets, such as GPS, mobile television, streaming video and streaming audio, or video on demand. It became very clear that the separation between GSM and CDMA was creating a number of challenges for users that wanted to move between different providers or use different networks that might be available in their area. To be able to converge these together, we introduced LTE. This is 4G technology in the cellular world. And LTE stands for Long Term Evolution.

This was a converged standard, so companies that used to be GSM or CDMA can now use one standard LTE to be able to send data over a wireless network. It’s based on GSM and what we call EDGE or the Enhanced Data Rates for GSM Evolution. You combine all those together to create this newer LTE standard. And it increased the throughput up to 150 megabits per second on the best possible mobile connection. In some areas you may find an upgraded version of LTE called LTE Advanced or LTE-A, where it effectively doubled the throughput on these LTE networks up to 300 megabits per second.

In 2020, we introduced a newer generation of mobile communication called our 5G or fifth generation cellular networking. These 5G networks introduced greatly enhanced speeds. And we will eventually have 5G networks that can perform at around 10 gigabits per second. These 5G networks greatly enhanced the speeds that we can use for data over these mobile networks. And in the best possible scenario, we should eventually get to 10 gigabit per second throughput from one single mobile device. As these networks are rolling out, you may find that you have speeds between 100 and 900 megabits per second, which is still much faster than the older LTE networks.

If we are able to greatly increase the speeds of the data going over these 5G networks, then we may be able to extend the functionality of our mobile devices. This could be especially useful for Internet of Things devices where you have many different devices on the network that need to have some type of connectivity. If bandwidth and speeds are suddenly not an issue, you should be able to greatly increase the capabilities of these IoT or Internet of Things devices. This would allow us to have much larger file transfers. We might increase the capabilities of the applications that we’re using. Or you may be able to upload much more data into the cloud for additional processing.

Many of the updates for our mobile devices occur in the operating system of the device itself. One of these updates is a PRL update. This is a Preferred Roaming List that allows your phone to understand where all of the appropriate towers are for the network that it happens to be using. This can be updated over-the-air. So you may see that your phone is performing an OTA update. And if that’s occurring, it may be because a preferred roaming list needs to be changed on your device.

On some mobile phones, you can combine or merge together the cellular network with an 802.11 network. This is when you turn your phone into a Wi-Fi hotspot. This is effectively your own personal data router that’s using the cellular network to communicate to the internet. So you could turn your phone into a hotspot. And now any other device in your area that communicates over 802.11, can use the internet connectivity that’s on your cellular network.

Your phone may support Wi-Fi hotspot capabilities, but your provider may limit what your phone is able to do. There may be an additional charge to enable that capability. And there may be data costs associated with the information you’re sending when you’re in this Wi-Fi hotspot mode. You’ll want to check with your cellular provider to see what options may be available for your mobile phone.