Table of contents:
- What is GSM?
- What is WCDMA?
- WCDMA vs GSM: What's the difference?
- Network coverage
- International roaming
- 4G, WCDMA or GSM: what's the difference in the near future?
When consumers think of mobile network providers, their main concerns are quality of service, support, pricing and other factors. When you choose a network operator, you also have to choose between a GSM or WCDMA network.
You've probably come across these terms before when choosing a new mobile phone, connecting or changing providers for the first time. But do you know what they mean and what is the difference between them? To make the right choice, you should take a closer look at how GSM differs from WCDMA and which one is better.
What is GSM?
GSM acts as the Global System for Mobile Communications and is now considered the communications standard on a global scale, especially in Asia and Europe, with availability in over 210 countries worldwide. It operates on four different frequency bands: 900 MHz and 1800 MHz in Europe and Asia, and 850 MHz and 1900 MHz in North and South America. The GSM Association is an international organization founded in 1987 dedicated to developing and overseeing the expansion of the use of this standard's wireless communications.
GSM usesa variant of TDMA (time division multiple access) that divides frequency bands into multiple channels. In this technology, voice is converted into digital data, which is transmitted over a channel and time slot. At the other end, the receiver only listens for the assigned time slot, and the call combines both signals. Obviously this happens in a very short time and the recipient does not notice the "gap" or time division.
What is WCDMA?
CDMA, or Code Division Multiple Access, became a standard developed and patented by Qualcomm, and subsequently used as the basis for the CDMA2000 and WCDMA standards for 3G. However, due to its proprietary nature, WCDMA technology has not received the global adoption that GSM has. It is currently used by less than 18% of networks worldwide, mostly in the US, but also in South Korea and Russia. What is the technical difference between GSM and WCDMA?
In WCDMA networks, digital calls are stacked on top of each other, assigning unique codes to differentiate them. Each call signal is encoded with a different key, and then they are transmitted simultaneously. Each receiver has a unique key capable of splitting the combined signal into its individual calls.
Both standards are multi-access, which means that multiple calls can go through the same tower. But as you can see, the main difference between the two has to do with how the data is converted into radio waves that your phone broadcasts andreceives.
The main reason telcos have had trouble rolling out the new format quickly is the difference in the frequency bands they use. Because of this, GSM-only phones could not communicate with WCDMA networks, and vice versa. To get around this, most device manufacturers had to apply multiple frequency bands for 2G and 3G networks. This ensured that mobile phones could be used on almost any network and anywhere in the world.
WCDMA vs GSM: What's the difference?
Before the advent of 4G LTE technology, the obvious difference between GSM and WCDMA devices was related to the SIM card. GSM phones came with a SIM card slot, but CDMA devices did not.
In other words, WCDMA is a phone-based standard with a subscriber number associated with a specific 3G capable device. If you want to switch to another phone, you will need to contact the provider, deactivate the old device and activate the new one. On the other hand, in GSM devices, the number is associated with the SIM card, so when switching to another device, all you have to do is put the SIM card into the new phone.
Network coverage is independent of whether it is GSM or WCDMA. What is the difference in this case? This characteristic rather depends on the infrastructure that the operator has. GSM networks are much more popular worldwide except in the US where Verizon Wireless, a (W)CDMA network, canboast the largest number of subscribers in the country.
When connecting domestically, it doesn't matter which network you use, as long as it has sufficient coverage. So, in Russia you can freely use WCDMA or GSM. What is the difference outside the country?
When it comes to international roaming, GSM has a lot of advantages: there are many more of these networks around the world, as well as many roaming rates between these providers. With a GSM phone, you also have the advantage that you can purchase a local SIM card wherever you are (provided you're using an unlocked device). In turn, you may not be able to fully access the WCDMA data connection, depending on the device and network compatibility.
4G, WCDMA or GSM: what's the difference in the near future?
With the advent of 4G and the adoption of LTE and LTE-Advanced as the standard by most network operators around the world, the GSM vs. WCDMA debate is taking less time. Today, you may notice that the latest smartphones designed for WCDMA networks also come with SIM card slots to take advantage of the network's 4G LTE capabilities.
The difference between GSM or WCDMA devices means that they cannot be interchanged even now and will never be cross-compatible, but this will not matter in the near future. This is due to the fact that modern developers continue tomove towards full transition to 4G LTE. This technology has obvious advantages.
Thus, with international roaming, the main factor is the quality of the voice call and the satisfaction of user needs for 3G data. These parameters can be equally good in GSM or WCDMA networks. What is the difference? The 3G modems built into these devices can show high functionality. But when it comes to factors such as availability, coverage, and price, 4G offers the best deal.