What is 4G?
If you’re looking to buy a new smartphone or tablet, or looking into subscribing to a new, faster mobile data package, I’m sure you’re familiar with the term 4G. Simply put, 4G means the fourth generation of wireless mobile networks. For consumers, this means faster data speeds, ideally suited for speed-intensive activities such as video streaming. For network carriers, 4G introduces a way to simplify network infrastructure, while also offering improved quality of their services for subscribers.
Today, we’ll be taking an in-depth look at what 4G is, and the various types of current and upcoming 4G networks. Let’s get started!
What is 4G? – The technical definition
In 2007, the International Telecommunication Union’s Radiocommunication Sector (ITU-R) defined a new global standard called International Mobile Telecommunications-Advanced (IMT-Advanced).
IMT-Advanced will be an IP (Internet Protocol) packet-switched network that uses VoIP (Voice over IP) instead of separate telephone call channels like what is used in 3G networks. Features of IMT-Advanced networks, as defined by the ITU-R include –
- a high degree of commonality of functionality worldwide while retaining the flexibility to support a wide range of services and applications in a cost efficient manner
compatibility of services within IMT and with fixed networks
capability of interworking with other radio access systems
high quality mobile services
user equipment suitable for worldwide use
user-friendly applications, services and equipment
worldwide roaming capability
enhanced peak data rates to support advanced services and applications (100 Mbps for high mobility devices, and 1 Gbps for low mobility devices)
Leaving aside the technical aspects of the definition relevant to network operators, what is important for us, the consumers, is the peak download speeds, which are defined as 100 Mbps for high mobility devices, that is, data connectivity on your smartphone while in a moving vehicle, and up to 1 Gbps for low mobility devices, that is, when you’re stationary.
What is True 4G?
Taking a look at the requirements specified by IMT-Advanced, it’s easy to see that current networks marketed as 4G don’t meet the standard. It wasn’t until October 2010 that the ITU-R completed an assessment of six candidates to be considered True 4G, with LTE-Advanced and WiMax 2 making the cut.
However, under pressure from 3GPP, IEEE and network carriers, HSPA+,WiMax, and LTE, were also considered 4G even if these networks don’t meet the IMT-A requirements, since network carriers had already begun investing in these technologies and marketing them as 4G. This consideration led to the coining of the term True 4G, which will be the next step in 4G evolution.
Types of 4G networks
Even though network operators around the world all use the term 4G to describe their current high-speed data networks, there are many types of 4G networks, which include WiMax, HSPA+, and LTE, to be followed by True 4G networks such as LTE-Advanced and WiMax-Advanced. Here’s a quick overview of the various types of 4G networks –
Current 4G networks – “Faux” G
WiMAX, short for Wireless Interoperability for Micromave Access, is a technology standard for long-range wireless networking based on the IEEE 802.16 set of wide-area communications standards. At one point, WiMAX was considered to be a leading form of mobile data connectivity, but because of limited adoption and less than satisfactory real world speeds, WiMax, in its current iteration is not upto 4G standards.
HSPA+ (Evolved High Speed Packet Access) is the next iteration of HSUPA and HSDPA 3G standards with speeds comparable to current LTE networks (which don’t meet true 4G standards either). Theoretical speeds are said to feature download speeds up to 168 Mbps and uplink of 22 Mbps, with most HSPA+ networks around the world feature a theoretical 21 Mbps(download) speed, with a select few featuring 42 Mbps and 84 Mbps networks. These are of course, theoretical, with actual download and upload speeds at around 10-30% of the theoretical speed. In a lot of markets, except in the USA, an HSPA+ network is unofficially considered and marketed as a 3.5G network.
LTE, or Long Term Evolution, boasts theoretical downlink speeds of 100 Mbps and uploads of 75 Mbps. LTE, which is an IP-based system, is a complete redesign and simplication of 3G network architecture resulting in a significant reduction in transfer latency. Because of this, LTE is not compatible with 2G and 3G networks and also functions on an entirely different wireless spectrum. Unfortunately, this means that erecting an LTE network requires it to be built from the ground up. Coverage currently varies depending on your carrier and real world data speeds are often only a little faster than HSPA+. LTE lacks spectral efficiency and speed means that current 4G LTE networks falls far behind true 4G capabilities.
Upcoming 4G networks – True 4G
LTE Advanced is the next major step in the evolution of LTE networks, and is the beginning of true 4G. LTE-A is not only about faster data speeds, but is to provide IMT-Advanced functionality while allowing for backward compatibility with current LTE devices to avoid a second major overhaul. LTE-Advanced will provide 1 Gbps downlink for low mobility conditions, with 100 Mbps for high mobility devices, as specified by the IMT-A standard. LTE Advanced promises better coverage, more stability, and much faster performance. You can find out more about LTE-Advanced here.
The WiMAX industry developed WiMAX 2, based on the IEEE 802.16m standard, to improve mobile WiMAX network capacity and deliver faster data rates to consumers. On paper, and in field trials, WiMAX 2 was successful, and ITU-R approved WiMAX 2 as a next-generation IMT-Advanced standard. Unfortunately, because most WiMax network providers (ala Sprint) have abandoned WiMax in favor of LTE, WiMax 2 will serve as complementary to LTE-Advanced, and not as a competition. WiMax 2 will target vertical applications and other niche markets.