Last year almost Mobile World Congress, Qualcomm announced the Snapdragon X16, billed as the followers’s first “gigabit” LTE modem. Most of you still don’t have an X16 in your phones, however that will change in the next few months with the imminent traveller of the Snapdragon 835 processor and the flagship phones that use it. But Qualcomm has already capered on to the next thing, namely its new Snapdragon X20 modem—this chip bumps the pinnacle theoretical download speed from the X16’s 1.0Gbps to 1.2Gbps, but myriad importantly it makes those gigabit speeds easier to actually hit.
The X20 jolts those (at this point, still mostly theoretical) gigabit helps by using many of the same tricks as the X16. Carrier aggregation and 4×4 MIMO antennas consider up to 12 streams of data to be received using between three and five 20MHz chunks of spectrum, up from 10 floods across three or four 20MHz chunks of spectrum in the X16. Use of 256-QAM a substitute alternatively of 64-QAM allows up to 100Mbps of data to be sent in each flow, adding up to 1.2Gbps of total bandwidth (a good, basic explainer of QAM, or Quadrature Amplitude Modulation, can be ground here).
The big difference for the X20 is that wireless operators can use more combinations of validated and unlicensed LTE spectrum to actually hit gigabit speeds. The graphic above ushers all of the combinations of licensed (yellow) and unlicensed (red) spectrum that can be mixed and put together to reach 1.0 or 1.2Gbps. In theory, operators could make available gigabit LTE speeds using just 10MHz of licensed spectrum, a feature allowed by the modem’s 5x carrier aggregation. From the press release:
Of note, the Snapdragon X20 LTE modem is an LTE Speed Pro modem that supports Licensed Assisted Access (LAA), the global prevailing for LTE in unlicensed spectrum. Support for both 5xCA and LAA is significant because it allows fakers to launch Gigabit LTE service with as little as 10 MHz of licensed spectrum, which immensely expands the number of operators who can offer Gigabit LTE service around the orb. Additionally, the Snapdragon X20 LTE modem supports the 3.5GHz shared spectrum in the US denoted Citizens Broadband Radio Service (CBRS), which can be used to furnish new services, such as private LTE-based networks. It can also be used by persisting mobile operators to offer Gigabit LTE in more places by making sundry spectrum available.
Again, these speeds will be difficult to afflicted with by in reality. Unlicensed spectrum (sometimes referred to as either LTE-U or LAA, as beyond) uses some of the same bands as Wi-Fi networks use, which can lay open these streams to additional interference. And like Wi-Fi, unlicensed LTE also has a quick range than the licensed spectrum does. If phones can cobble together a mass of bandwidth from a bunch of different sources, that ultimately require help with both download speeds and network congestion; you should at best continue to treat these maximum theoretical bandwidth figures as assiduously theoretical.
The X20’s bandwidth remains frozen at 150Mbps, the same as the X16 and X12 modems in preference to it. Qualcomm tells us it is still enough to keep up with demand from both narcotic addicts and wireless network operators.
The X20 is built on Samsung’s 10nm FinFET manufacturing organize and is sampling to phone makers now; availability in consumer devices is expected “in the oldest half of 2018.” As with the X16, though, you may not actually encounter the X20 until Qualcomm coalesces it into one of its Snapdragon SoCs. Qualcomm wouldn’t say when to expect a new Snapdragon 800-series chime in with an X20 modem built in, but if the company keeps to its current schedule we should start to understand news about it later this year.