LTE-A (advanced) How it works

LTE Advanced is the next major step in the evolution of our LTE networks. It’s a new network technology that’s expected to both help band-aid the massive increases in mobile data demand, and deliver much higher data speeds for all. That means better coverage, greater stability, and faster performance. And it’s not just a little faster. Most of today's flagship devices( HTC One, S4 and Sony Z Ultra) all run on standard 4G LTE with Samsung announcing a S4 variant to be LTE A certified. The table below explains further how fast LTE-A really is. 

LTE Advanced is a lot faster

This table gives you an at-a-glance idea of how the likely speed ranges compare. We’ll have to wait for the release to get solid figures.

	3G	WiMax	HSPA+	LTE	LTE Advanced
Peak rate	3 Mbps	128 Mbps	168 Mbps	300 Mbps	1 Gbps
Download rate (actual)	0.5 – 1.5 Mbps	2 – 6 Mbps	1 – 10 Mbps	10 – 100 Mbps	100 – 300 Mbps
Upload rate (actual)	0.2 – 0.5 Mbps	1 – 2 Mbps	0.5 – 4.5 Mbps	5 – 50 Mbps	10 – 70 Mbps

The highest possible rates are never achieved in real world conditions. Actual rates will be variable, but we can expect LTE-A to be at least five times as fast as most LTE networks today, and that’s great news for video streaming addicts, as long as they have a healthy data allowance.

How did we get here?

The roll out of 4G (fourth generation) mobile networks in the U.S. was slightly complicated by the fact that some carriers decided to label what was really enhanced 3G tech as 4G. This led to the LTE (Long Term Evolution) standard being described as “true 4G” or “4G LTE” when it finally rolled out, but actually that turned out not be strictly accurate either. Check out our 4G Guide for more details on the various flavors of “4G” currently on offer. The first LTE roll-out did not meet the requirements for 4G when it came to things like peak data rates, which were defined by the International Telecommunication Union (ITU).

Now that LTE Advanced is on the horizon we will be enjoying 4G for real, but what exactly is it? Let’s take a closer look and try to explain.

How LTE Advanced works

LTE Advanced is supposed to provide higher capacity, an enhanced user experience, and greater fairness in terms of resource allocation. It does this by combining a bunch of technologies, many of which have been around for some years, so we’re not really talking about the implementation of an entirely new system here.

According to Jeanette Wannstrom, in an article for 3GPP, “The main new functionalities introduced in LTE-Advanced are Carrier Aggregation (CA), enhanced use of multi-antenna techniques (MIMO) and support for Relay Nodes (RN).”

Carrier Aggregation enables greater speeds because it allows you to download data from multiple sources at the same time. Instead of connecting to the best signal in your vicinity, your smartphone can combine multiple signals, even on different frequencies. Up to five of these “component carriers,” each offering up to 20MHz of bandwidth, can be combined, which creates a maximum aggregated data pipe up to 100MHz.

MIMO stands for Multiple Input Multiple Output, and it can increase the overall bitrate by transmitting two (or more) different data streams on two (or more) different antennas. Qualcomm’s LTE Advanced white paper explains that by leveraging more radio links through more antennas, you get “higher spectral efficiency.” In plain speak, these networks are able to do more with less.

Relay Nodes are described by Wannstrom as, “low power base stations that will provide enhanced coverage and capacity at cell edges.” They’ll increase the range of coverage and ensure that speeds are good, even if you’re on the outskirts of your network.

What do we need?

The technology is backwards compatible, so it won’t adversely affect existing LTE users. However, you won’t automatically be able to enjoy LTE Advanced when the carriers roll it out; you’ll need a new device with an LTE-A chip in it. Qualcomm, Broadcom, and Nvidia, among others, have been working on these chips and Samsung has already announced plans for a new version of the Galaxy S4 which will support the LTE Advanced standard.

Information in part provided by digital trends.