One of the big improvements that is coming to mobile networks this twelvemonth is Gigabit LTE. Yous might take heard of it already – companies are gearing up for deployments around the globe right at present – simply if not, it'll become a bigger talking point in the months to come up. Gigabit LTE is set to hit everything from smartphones and laptops to portable hotspots and cars.

In this commodity, nosotros'll be explaining what you lot need to know about the engineering science: how it works, what device y'all'll need to admission Gigabit LTE, where information technology is coming, and more. Read on to learn about the firsthand futurity in wireless technology.

What is the Engineering science Backside Gigabit LTE?

Gigabit LTE is an upgrade on existing cellular LTE technology that provides college connectedness speeds. As the proper name suggests, Gigabit LTE is a form of LTE that's designed to hit approximately gigabit downstream speeds at peak in platonic conditions. In other words, it would be theoretically possible to download over a cellular network at near 1 Gbps, or 125 MB/s.

To be articulate, "Gigabit LTE" only refers to gigabit-class peak downstream speeds in ideal conditions. In the real world, which we'll discuss afterwards in this article, you won't necessarily hit one Gbps on your device. Furthermore, upstream speeds are not gigabit-class: electric current Gigabit LTE implementations are paired with 150 Mbps upstream connections, which translates to theoretical maximum upload speeds of eighteen.75 MB/s.

To fully sympathize the technology backside Gigabit LTE, we demand to start by discussing older LTE implementations and the various terms related to LTE technology.

Ane of the easiest elements to empathize is the naming scheme for LTE. Every few years, the standards group backside cellular technologies, the 3GPP (3rd Generation Partnership Program), releases an update to their standards. Part of these 3GPP Releases include updates to LTE technologies and specifications, aimed at improving superlative speeds amidst other things.

Each 3GPP Release includes several new LTE user equipment Categories that ascertain the diverse technologies required to attain certain specifications. For instance, 3GPP Release 8 included the LTE Category 4 specification, which outlined how 150 Mbps downstream and 50 Mbps upstream could be achieved.

Gigabit LTE refers to LTE Category sixteen downstream, which was first introduced in 3GPP Release 12. Current implementations see Gigabit LTE paired with an LTE Category xiii uplink for 150 Mbps superlative theoretical uploads.

One of the most common LTE specifications widely adopted by cellular networks and devices is LTE Category iv. To accomplish its 150 Mbps downlink speeds, LTE True cat. 4 uses 64QAM and 2x2 MIMO on a single 20 MHz carrier.

You might be wondering what all those terms mean. Here is a uncomplicated explanation for you.

  • QAM, or Quadrature Amplitude Modulation, describes the digital modulation used in the LTE channel. A higher QAM number indicates more bits are used for the transmission of each information symbol, and without going in to the complexities of modulation, more than bits equate to faster speeds. Equally a trade-off, more $.25 (higher QAM values) are harder to receive and decode as the signal quality degrades.
  • MIMO, or Multiple-Input and Multiple-Output, refers to (as far as we're concerned) the amount of antennas used in both the transmitting and receiving devices. 2x2 MIMO ways the transmitter (the first number) and the receiver (the second number) both use two antennas. 4x4 MIMO, which we'll discuss later, uses four antennas for both. More antennas ways faster speeds and greater reliability.
  • The carrier is substantially the electromagnetic aqueduct through which data is transmitted. The carrier has a size (bandwidth) in MHz, which refers to how much electromagnetic spectrum it consumes. The larger this bandwidth, the better functioning you can achieve. LTE uses a maximum carrier bandwidth of xx MHz.
  • The band is the range of frequencies at which the carrier is transmitted. These values – simplified to a unmarried frequency – are ordinarily provided by your carrier, and are a key component to ensuring devices are compatible with networks. Equally an case, ane of the most widely used bands is Ring three, which is listed at 1800 MHz simply encompasses 1710 to 1785 MHz for transmission. A single LTE carrier would occupy up to twenty MHz of this band, for instance from 1710 to 1730 MHz.
  • Carrier aggregation (CA), which volition become important later, is a system where multiple carriers are combined to improve throughput and speeds. 2xCA, for instance, combines two 20 MHz carriers for a total of 40 MHz of bandwidth, effectively doubling the speed. These carriers are typically aggregated across bands rather than within a unmarried band, such that 2xCA may utilize 20 MHz from the 1800 MHz ring forth with 20 MHz from the 2100 MHz band.

QAM, MIMO and CA are combined in diverse configurations for each LTE Category, resulting in their rated maximum speeds.

As an case, the baseline speed you can achieve using a unmarried 20 MHz carrier, single antenna (no MIMO) solution with 64QAM is 75 Mbps. Category iv LTE uses 2x2 MIMO, which uses ii antennas thus doubling the maximum downlink speed to 150 Mbps.

The Snapdragon 810 SoC'due south modem supported Category ix LTE, which introduced 3x20 MHz CA for the outset time

Another more-recently implemented solution is Category 6 LTE. In the downlink, Cat. 6 LTE achieves 300 Mbps typically using a 2x20 MHz CA with 2x2 MIMO solution (although other configurations are supported). In the aforementioned case, we're seeing four LTE streams – two from each aggregated carrier multiplied past two antennas – at 75 Mbps each, for a total link speed of 300 Mbps.

Some other step frontwards is Category 12 LTE, which isn't as widely deployed as True cat. iv or Cat. 6 as it's much newer. True cat. 12 increases the carrier aggregation to 3x20 MHz CA, but to hit its listed 600 Mbps speeds, it too employs upgraded modulation: 256QAM. With 256QAM, each stream is 33 percentage faster, going from 75 Mbps to 100 Mbps. With 3x20 MHz CA and 2x2 MIMO, Cat. 12 LTE uses six streams at 100 Mbps each, for a full of 600 Mbps.

If you've been following along so far, yous'll notice a pattern. Each new LTE Category supports a faster downlink speed, and this is made possible by increasing the QAM, MIMO or CA levels. Gigabit LTE takes this to the extreme.

To achieve Gigabit LTE, 256QAM is implemented for 100 Mbps per stream. ten streams are then used to achieve 1000 Mbps speeds, in a circuitous combination of technologies. The beginning viii streams are provided through 4x4 MIMO on 2x20 MHz CA (four antennas multiplied by two carriers). A further two streams are provided by 2x2 MIMO on an additional aggregated carrier, for a total of 10 streams and 3 carriers.

In short, Gigabit (Category 16) LTE is 256QAM, 3x20 MHz CA, and 4x4 MIMO.

The actual rated downlink speed achieved through this combination of technologies is not quite ane Gbps, simply 979 Mbps. Later we'll discuss what sort of real-world speeds you can expect.

Paired with a Cat 16. LTE volition be a Cat 13. LTE uplink in virtually situations, because Cat 16. LTE does non include its own uplink specification. Maximum upstream speeds of 150 Mbps are provided through 2x20 MHz CA and 64QAM (two 75 Mbps streams).

It's also worth mentioning Cat 16. LTE'southward secondary configuration, which doesn't require more than complex 4x4 MIMO antenna arrays. Using 2x2 MIMO, 256QAM and 4x20 MHz CA, speeds of up to 800 Mbps are possible. This isn't quite Gigabit speed, but still far superior to most LTE networks deployed worldwide.

One of the advantages to Gigabit LTE is that past including support for technologies like 4x4 MIMO and 3xCA, even if y'all're not right next to a belfry and able to accomplish Gigabit speeds, you'll have the best access to whatever network is available in your area. Let's say you're just outside the metropolis limits and in that location's only access to two carriers instead of three. If you're lucky and these towers support 4x4 MIMO, you could achieve upward to 800 Mbps. If you're farther out, it's possible to drop downward to 64QAM and 2x2 MIMO across iii carriers to still accomplish 450 Mbps. Even more combinations are theoretically possible.