What is GSM, and how is it different from other networks?

What is a GSM network?

GSM technology took off in the early ‘90s, transforming mobile communication by making calls and text messaging more reliable. Finland was the first country to launch a commercial GSM network, marking the shift from analog to digital mobile systems. By 2010, GSM dominated nearly 80% of the global mobile market, proving just how essential it had become.

One of GSM’s greatest strengths is its ability to evolve. Over the years, upgrades like GPRS and EDGE enhanced data speeds, paving the way for mobile internet access. While GSM has now largely been replaced by LTE and 5G, it still plays a role in some rural and developing areas where newer networks are expanding.

With its global reach and lasting impact, GSM has been a key player in mobile communication for decades. Though many carriers are now phasing it out, its legacy lives on as the foundation for modern wireless networks.

GSM network structure

The GSM network operates smoothly thanks to four key components — mobile devices, the base station system, the core network, and operational support systems.

Mobile devices, such as smartphones and tablets, connect to the network using SIM cards, which store user identity details. When you turn on your phone, the network checks this information to verify your access to calls, messages, and mobile data.

The base station system acts as a bridge between mobile devices and the main network. It includes cell towers, which send and receive signals to and from phones, and controllers, which manage multiple towers at once, ensuring smooth call connections and efficient use of network resources.

The core network is responsible for directing calls and data. It includes systems that keep track of users as they move between locations, ensuring they remain connected without interruptions. It also handles the process of routing calls and messages to the right destination, whether the recipient is in the same city or halfway around the world.

Finally, the operational support system keeps everything running smoothly. It monitors network performance, troubleshoots technical issues, and ensures that mobile services remain reliable for users.

How does the GSM technology work?

Let's imagine you're making a phone call. Thanks to the hardware within the phone, it connects to a nearby cell tower as soon as you make the call. Your SIM card plays a central role here — it holds your unique information, such as your phone number and carrier details, ensuring that calls and data are correctly routed to and from your device.

From the tower, your signal moves to a base station, which acts as a traffic controller and sends it to the network’s core system. There, a switching center figures out where your call needs to go — whether it’s your friend across town or a contact halfway around the world — and makes the connection. This entire process takes seconds. 

For data, it's a similar process, but instead of connecting a call, the network routes your internet usage through secure pathways, ensuring you can browse, stream, and share content efficiently.

GSM features

GSM offers several features that enhance mobile communication. One key aspect is security, with encryption protecting voice calls and data transmissions. While older encryption methods have known weaknesses, newer security improvements help strengthen mobile network protection.

GSM also introduced mobile data with technologies like GPRS and EDGE, enabling users to browse the internet and send messages. However, true simultaneous voice and data usage became widely available only with 3G and newer networks.

Global roaming is another major benefit. As an international standard, GSM allows users to stay connected across different countries, provided their carrier has roaming agreements in place. For travelers, this means easy connectivity abroad without manually switching networks.

The flexibility of SIM cards also makes GSM convenient. Since user identity and network access are tied to the SIM, swapping devices or changing carriers is simple.

To manage network resources efficiently, GSM uses time-division multiple access (TDMA), allowing multiple users to share bandwidth without interference. This technology ensures that calls and data transmissions remain smooth and reliable.

GSM limitations

Although widely used, GSM technology has several limitations that can affect its performance and accessibility. One significant limitation is electronic interference. GSM networks rely on a pulse transmission method that occasionally clashes with other electronic signals. This interference can disrupt communication, leading to poor call quality or unstable data connections.

Another limitation is bandwidth sharing. GSM networks allow multiple users to share the same bandwidth, which works well in most cases. However, peak usage times can result in slower data speeds and delays.

Device compatibility can sometimes be a hurdle, too. Basic GSM features like making calls or sending texts work just fine on most GSM-compatible devices. But if you want faster data speeds with technologies like EDGE or GPRS, you'll need a more advanced phone. The downside? In places where these devices are hard to find or too expensive, people can’t fully tap into everything GSM networks offer. 

Lastly, infrastructure challenges can impact GSM services. Natural disasters or technical failures can disrupt network coverage, and improving signal strength often requires costly and complex installations, such as repeaters. It's especially problematic in remote or underserved regions, where maintaining and upgrading the network infrastructure becomes a logistical and financial burden.

GSM for eSIM users

For eSIM users, GSM technology's global adoption and flexibility take on even greater importance. Since GSM networks rely on SIM cards for user identification, transitioning to an eSIM — a built-in, digital version of the traditional SIM — offers a lot of convenience. With an eSIM, users can switch carriers or plans without swapping physical cards, making the most of GSM's widespread international roaming and extensive coverage.

GSM's secure wireless infrastructure adds an extra layer of reliability for eSIM users, ensuring seamless communication and data security no matter where you are. To take full advantage of these benefits, ensure your phone is eSIM compatible. This allows you to experience the convenience and connectivity of modern mobile networks effortlessly.

GSM network operators in the US

Several major GSM network operators work across the United States:

• T-Mobile. As one of the largest GSM providers in the US, T-Mobile is known for its expansive network, competitive pricing, and innovative services, making it a top choice for millions of users nationwide.

• AT&T. Another important player in the GSM market, AT&T serves a wide range of customers, including those using its subsidiaries, FirstNet and Cricket Wireless. These services cater to traditional and prepaid markets while leveraging GSM technology for reliable connectivity.

• Cricket Wireless. Operating under AT&T, Cricket Wireless offers affordable prepaid plans powered by a GSM network. It's a popular choice for budget-conscious users.

• US Cellular. Although smaller than T-Mobile and AT&T, US Cellular remains a big part of the national GSM network. It delivers reliable communication services in its coverage areas, ensuring seamless connectivity for users. 

GSM vs. CDMA vs. LTE

GSM, CDMA, and LTE represent different generations of mobile network technologies, each with a unique approach to wireless communication.

CDMA (code-division multiple access) is an older network technology that allows multiple devices to use the same frequency band by assigning unique codes to each device. It has certain limitations in terms of speed and scalability, especially as mobile data usage grows. 

LTE (long-term evolution), also known as 4G, offers faster data speeds and improved network efficiency compared to CDMA. Its increased capacity allows carriers to provide better performance and faster internet speeds, making it the standard for most mobile networks. As we move towards 5G, LTE will become the backbone of global mobile communication.

The future of GSM technology

As mobile technology continues to evolve, the question of whether GSM will become outdated is asked often. While it has been the standard of global communication for decades, newer technologies like LTE and 5G, which offer faster speeds and greater efficiency, are becoming more typical.

However, GSM is far from obsolete. It still plays a vital role in many parts of the world, especially in areas where newer technologies have yet to be fully implemented.

For now, GSM will continue to serve a large user base, particularly in regions with limited access to 4G or 5G networks. Carriers maintain GSM networks in many countries, offering reliable mobile services in urban and rural areas. That said, we can expect gradual transitions over the coming years, with GSM networks eventually being sunsetted in favor of more advanced, higher-speed technologies.