OnQ Blog

Welcome to the era of Gigabit Class LTE

11 févr. 2016

Qualcomm products mentioned within this post are offered by Qualcomm Technologies, Inc. and/or its subsidiaries.

It is not often that one gets the chance to mark an important milestone like this one. And it is my privilege to tell you about it.

Today, Qualcomm Technologies announced the new Qualcomm Snapdragon X16 LTE modem. It is the first commercially announced modem to support Gigabit Class LTE speeds—up to 1 Gbps. 

Gigabit. Think about that. Up to one billion bits of information delivered to a mobile device in a mere second. And for those keeping track, that’s LTE Category 16.

Do you remember the thrill of experiencing your first 4G LTE device in action? This was a transformative moment for many people, and it has spurred the creation of new apps and experiences in mobile that were simply not possible before. Now, with the Snapdragon X16 LTE modem, we’re talking about peak download speeds that are nearly ten times as fast as those first generation 4G LTE devices.

Incredibly, peak download speeds are not the most impressive thing about the X16 LTE modem. Rather, it is how those speeds are achieved that is the key to this modem’s true power and potential.

You see, in late 2014 we introduced the X10 LTE modem, which was capable of peak download speeds of 450 Mbps. It achieved these speeds by aggregating three LTE carriers, each 20 MHz wide, for a total of 60 MHz of spectrum. The X16 LTE modem achieves up to 1 Gbps—more than 100 percent faster throughput than the X10—on that same amount of spectrum. That is truly astonishing.

How does it achieve this? By using more antennas and more-sophisticated digital signal processing. The Snapdragon X16 LTE modem can receive 10 streams of LTE data simultaneously using four antennas, and uses better signal processing to extract more bits out of every LTE transmission, boosting the throughput of each of the 10 streams to around 100 Mbps. Qualcomm Technologies was the first to introduce this type of digital signal processing with the X12 LTE modem (both the discrete version as well as integrated in the Qualcomm Snapdragon 820 processor), and we’re extending the technology with X16 LTE to 10 simultaneous streams instead of only six. You can read more about both of those techniques in the “Appendix for Nerds” below.

Counting the number of simultaneous LTE streams, and the throughput of each of those streams, thus becomes the new way to measure and compare LTE modem capability—the foundation for all connected mobile experiences.

But it gets even better. The Snapdragon X16 LTE modem is the very first to support LTE Advanced Pro, the next generation of LTE. With that, it supports a technology called Licensed Assisted Access (LAA). And it has the potential to vastly expand the number of operators that can offer Gigabit Class LTE service to their customers.

LAA, and its predecessor, LTE in unlicensed spectrum (LTE-U), are truly transformative technologies. They forever change how mobile networks are deployed, and open the door to more network capacity and faster speeds for users. How? They allow operators around the world to utilize free-to-use unlicensed spectrum to increase the number of LTE connections supported by their networks.LTE-U and LAA technology, combined with advanced antenna and digital signal processing techniques, enables operators worldwide, with as little as 20 MHz of licensed spectrum, to use LTE carriers in unlicensed spectrum to offer Gigabit Class LTE service. 

This combination—more antennas for more streams, better signal processing, and support for LTE-U and LAA—is the key to the realization of the promise of the Snapdragon X16 LTE modem, for more operators and more users around the world.

A little over two years ago, Qualcomm Technologies announced what was then called the Gobi 9x35 modem (now the Snapdragon X7 LTE modem). It promised peak Cat 6 download speeds of 300 Mbps. Many were skeptical of whether networks and devices that support those speeds would ever materialize.

Fast forward to today, and 86 LTE networks around the world support Cat 6 speeds or better, according to the GSA. And almost all flagship smartphones announced in 2015 supported Cat 6 or better, most of them powered by Snapdragon processors and LTE modems.

Why am I diving into the past? To emphasize that while you may be surprised that we’ve arrived at this era of Gigabit Class LTE so soon, it is in fact closer to reality than you may realize. In fact, we expect the first devices featuring the Snapdragon X16 LTE modem to be available in the second half of 2016, on networks that support their advanced capabilities.

Welcome to the era of Gigabit Class LTE.

Appendix for Nerds

The Snapdragon X16 LTE modem exploits multiple input, multiple output (MIMO) antenna technology to receive more “spatial streams”, and thus more data, from the LTE network. Most LTE devices today can receive data on two antennas simultaneously, using 2x2 MIMO technology. In comparison, the Snapdragon X16 LTE modem supports 4x4 MIMO—four antennas on the LTE base station, transmitting to four antennas on the mobile device. Not only that, but it also supports 4x4 MIMO on two aggregated LTE carriers.

The result is that the Snapdragon X16 LTE can receive 10 spatial streams of data simultaneously, divided across three LTE carriers. In comparison, the Snapdragon X12 LTE modem can receive six spatial streams across three LTE carriers.

The Snapdragon X16 LTE modem boosts the throughput of each of those spatial streams by employing more sophisticated digital processing to decode LTE transmissions modulated with 256-QAM. We first introduced this technology in the Snapdragon X12 LTE modem—both the discrete version as well as the one integrated in the Snapdragon 820 processor (you can read description of how it works in the Appendix for Nerds in the X12 LTE blog post). With 256-QAM, 33 percent more bits can be encoded into each LTE transmission, increasing the throughput of each spatial stream from around 75 Mbps to around 100 Mbps.

In total, then, the Snapdragon X16 LTE modem can receive 10 simultaneous streams of LTE data, and each stream carries ~100 Mbps, because of 256-QAM. And 10 x ~100 Mbps = 1 Gbps. That’s how the Snapdragon X16 LTE modem achieves Gigabit Class LTE speeds. 

Qualcomm Snapdragon is a product of Qualcomm Technologies, Inc.