This is a short primer that covers how mobile phone signals work, how each generation (e.g 2G, 3G, and 4G) differs from the last and what type of phone you should consider buying if you want to ensure you have the best possible coverage, call quality and internet speeds from your device.
Before we begin please take note that I am not an expert in this subject and can only offer a fairly basic explanation. Questions relating to whether what works / what doesn’t is fine, but more technical queries should be directed towards your carrier / provider.
Let’s start off with a brief explanation of the different mobile signal Generations – what’s 2G, 3G and 4G? 2G / 3G and 4G are simply the names of standards that have evolved over the years. Prior to all of these mobile phone signals were analogue but it was quickly replaced with digital transmission signals which provided the extra benefit of better quality calls, better signal penetration and data services such as SMS, MMS and IP (internet protocol).
- 2G was introduced in the 90’s and was comprised of two different standards – CDMA and TDMA. Here, we use the GSM standard which is based on TDMA, and 80% of subscribers around the world typically use GSM. It is a very old standard that is to be retired, however many countries still use the 2G standard and your phone will often fall back to 2G when 3G or 4G connections aren’t available. On some older phones, you can see a ‘GPRS’ icon or just a single ‘G’. This means you’re using the older 2G network.
What this means for you : Users of older mobiles that ONLY use GSM signals will no longer be able to access mobile services once 2G is shut down in Australia. Likewise, users of DUAL SIM handsets that typically have 2G-only services in their second SIM slot will no longer be able to make / receive calls on their second SIM.
If you still own a 2G phone, you can probably give it away, ebay it or donate it to the needy.
Don’t worry about whether your new phone supports 2G or not, because it’s obsolete technology anyway.
- 3G is an upgrade over the existing 2G GSM networks, with some extensions and improvements, and was relatively easy to adopt as existing 2G towers could be upgraded to provide WCDMA coverage. 3G is a large improvement over 2G because it now not only allows for faster data transmission, but also allowing for simultaneous use of data and voice at the same time. 3G has undergone many changes and upgrades since it’s inception and now has the following standards implemented:
- Evolved High Speed Packet Access, or HSPA+, allows for the phone to receive calls when receiving data over the network, as well as a data transmission rate of 42mb/sec in Australia. This upgrade was termed “3.5g” because of it’s theoretical max speeds of 168Mbps (but this was never delivered here)
- Enhanced Data rates for GSM Evolution (EDGE) — is a backwards compatible standard design to work with GSM. You can sometimes see your phone fall back in to EDGE mode when you are out of range of a 3G tower — this is denoted by a capital “E” on your Android phone. In this mode, you might not be able to access data services, but can still make or receive phone calls via the GSM network. EDGE is not considered a true 3G standard however.
In Australia, three 3G frequencies are:
- 850MHz (B5) – Telstra, Vodafone
- 900MHz (B8) – Optus, Vodafone
- 2100MHz (B1) – Telstra, Optus, Vodafone
- What this means for you: Many smartphones nowadays should cover at least all three of these 3G frequencies. However, beware that some budget phones imported from say, China, may only cover 850mhz or 900mhz, but not both, in an effort to cut down on production and licensing costs. Avoid getting a phone that does not support all three frequencies.
- 4G LTE is probably of the greatest interest and is probably the most confusing to most. LTE is the next-step of the evolution of UMTS (3G) and HSDPA (3.5G) is a complete redesign and simplication of 3G network architecture resulting in a marked reduction in transfer latency. Because of this, LTE is not compatible with 2G and 3G networks and thus, functions on an entirely different wireless spectrum. Unfortunately, this means that erecting an LTE network requires it to be built from the ground up. This is one of the main factors behind the delayed launch of complete 4G LTE networks.
The industry is using what is called LTE Categories to describe the LTE network capabilities. There are 11 different categories that are defined, and from a consumer perspective, they mainly differ in terms of theoretical speed. The whole table can be seen here.
According to Wikipedia, CAT6 LTE provides a max downlink speed of 301.5 Mbit/s. Cat 6 is already available in some metro areas for users with Telstra and Optus, and in testing we’ve seen real-world download speeds of 150Mbps and uploads still around the 35-50Mbps mark.
- What is VoLTE
VoLTE or Voice over LTE is a feature that allows certain handsets to place phone calls over the 4G network, rather than falling back on 3G GSM networks. Without VoLTE, placing a phone call causes your phone to temporarily disconnect from the 4G network, pick up a 3G connection and receives / transmits voice data over 3G GSM.
VoLTE changes this, by allowing phone calls to be placed on 4G networks, typically over SIP or session initiated protocol. This technology is quite similar to Skype or Viber.
VolTE compatible devices
To see if your phone supports VoLTE, check your user manual or google online. Not every device supports VolTE and most carriers require your phone to be running their own firmware or operating system in order to have access to VolTE features. As such, many imported phones might not support VolTE when used in Australia, and may require software updates in order to work properly.
Australia is currently using these LTE bands
- B1 2100 MHz FDD [Telstra, Optus Tasmania, Vodafone]
- B5 850 MHz FDD [Vodafone only, Rolled out in capital cities and regional Queensland]
- B3 1800 MHz FDD [Telstra, Optus, Vodafone]
- B7 2600 MHz FDD [Telstra, Optus]
- B8 900 MHz FDD [Telstra, a handful of sites, utilises spectrum previously used by 2G]
- B28 700 MHz FDD [Used by all major network providers, including Telstra, Optus, Vodafone, TPG]
- B40 2300 MHz TDD [Optus (Vivid Wireless)]
The above is a list of 4G LTE frequencies. Some of these frequencies may overlap across different telcos, some do not, but you can generally expect that Telstra will provide the best experience in terms of signal strength and coverage.
What Information on specifications should I be looking for
It’s pretty easy to work out what you should buy. Different phone manufacturers may produce specific models for different regions and countries, so often the best way to ensure you get maximum compatibility is to just buy the Australian model from a local store. For example, the Nexus 5X comes in a few different versions.
However, if you’re importing from overseas you might run into some issues where the phone might only partially support your carrier and you might be missing some crucial (or not so crucial) LTE bands. Use GSM Arena or use Will my Phone work? to find out what frequencies are supported and do your research before you buy!
Some comments regarding these frequencies
* 700Mhz, Band 28 - Widely regarded as a must-have LTE network band as it is the lowest band in the LTE frequency spectrum available to the market. This network band provides superior range to the previous best band which was 850mhz, and because of it's lower frequencies it boasts better building penetration, giving users stronger connections in buildings and enclosed areas. However, this band is fairly 'narrow' and while it provides better coverage in Australia, it won't allow users to reach peak speeds with just this band alone.
* 850Mhz, Band 5 - This network frequency was originally used for Telstra's obsolete analogue network (1G), then eventually allocated for 3G services on Telstra's NextG network. This band, like B28, offers good building penetration and relatively wide coverage. It is still being used by Telstra for providing 3G services, and Vodafone for 4G services.
* 1800Mhz, Band 3 - This band offers no building penetration, and therefore, not practical in indoor locations. Provides additional 4G capacity in high density areas and services mostly locations that are closer to network towers.
* 2100Mhz, Band 1 - First used by the “Three” network provider for 3G services, this network band has been repurposed to provide high-speed, and high-bandwidth coverage in high density areas.
* 2300Mhz TDD, Band 40 - Owned and deployed by Optus and also VividWireless (an ISP known for providing Fixed Wireless broadband services). It now also forms part of Optus's LTE network
* 2600Mhz, Band 7 - Deployed nationwide, with Telstra owning a larger chunk of the band. It is used for highly populated areas and is widely deployed by Optus.
Cited sources and recommend reading:
- Whirlpool forums
- Whistle Out