The number of LTE-Advanced networks almost doubled in the first half of 2015, using carrier aggregation (CA) to provide user experience and network performance gains.  This has benefited Qualcomm, which offers the most advanced and comprehensive line of cellular chipsets for LTE mobile devices.  But what comes next after carrier aggregation, and which chip suppliers will benefit?

The majority of operators hold licenses to relatively small blocks of spectrum, and they need carrier aggregation across three carriers (3x) to reach aggregate bandwidth of 40 MHz for LTE Cat. 6 speeds (300 Mbps downlink, peak), which is emerging as the de facto minimum for premium smartphones.  To date, only Qualcomm offers integrated baseband-applications processor SoCs that support 3x downlink (DL) CA.

Next up for LTE-A will be faster DL and UL peak rates using 256-QAM and 64-QAM, respectively, and 4 x 4 DL MIMO, which has value as an alternative for higher DL data rates for operators that lack spectrum.  The Qualcomm Snapdragon 820, now shipping and due to appear in smartphones in Q1 2016, supports LTE Cat. 12 DL (600 Mbps) with 3x CA, LTE Cat. 13 UL (150 Mbps) using 2x CA, 4 x 4 DL MIMO, 256-QAM DL and 64-QAM UL.  The SoC also supports LWA (simultaneous licensed LTE + Wi-Fi access), and LTE-U, giving operators more options for supporting higher data rates.

LTE Baseband Processors with Leading Performance

*Summary of specifications to the best of our knowledge as of November 21, 2015.  “Type” = Level of Integration.  “SoC” = Baseband-applications processor; “Modem” = Baseband processor (need external apps processor in smartphones).  “SD” = Snapdragon.

Samsung’s Shannon 333 modem used in the Samsung Galaxy S6 supports Cat. 6 DL (2x CA) and Cat. 4 UL.  Samsung announced the more highly integrated Exynos 8 baseband-apps processor SoC in November 2015, stating that the SoC would support LTE Cat. 12 DL and LTE Cat. 13 UL, but Samsung provided few details.

HiSilicon, a subsidiary of Huawei, announced the Kirin 950 baseband-applications processor SoC the first week of November, 2015.  The processor supports LTE Cat. 6 using 2x DL carrier aggregation, meeting the needs of most operators today, but HiSilicon plans to make the chip available only in selected Huawei smartphones.  This year, HiSilicon has supplied LTE chips for about 30 percent of Huawei phones.  Next year, the target is 50 percent. 

HiSilicon also announced new details on the Balong 750 slim modem, which will support LTE Cat. 12 DL and Cat. 13 UL, and DL MIMO up to Transmission Mode 9, apparently matching the modem performance of the Snapdragon 820.  According to a Chinese press report, the Balong 750 will support 4x DL carrier aggregation, but not 256-QAM, to reach 600 Mbps.  The Balong 750 will not support LTE-U, and HiSilicon has said the chip will ship in portable and fixed LTE routers and USB dongles, raising questions about whether the power consumption will preclude use in smartphones.  As a slim modem, the Balong 750 lacks an integrated applications processor.

The Intel XMM 7360 platform supports LTE Cat. 10 DL (450 Mbps using 3x DL) and 100 Mbps UL using 2x CA.  The X-Gold 736 baseband processor IC used in the XMM 7360 platform requires adding an external applications processor if used in a smartphone, so the X-Gold 736 is not equivalent to Qualcomm’s Snapdragon baseband-apps processor SoCs.  Intel recently requested that the 3GPP allow 256-QAM as an option for LTE Cat. 6 / 7 and Cat. 9 / 10, arguing that this would allow operators to reach the peak data rates defined by these categories by aggregating less bandwidth, that is by running 256-QAM on one or two carriers.  One interpretation of this is that even after firmware updates, Intel’s X-Gold 736 does not have the processing capability to support 256-QAM on three carriers.  If it did have this capability, it could run at LTE Cat. 12 DL speed (600 Mbps).

Intel has released only preliminary specifications for the SoFIA LTE baseband-applications processor, but so far has said that the SoFIA LTE will support Cat. 6 DL and Cat. 4 UL.

MediaTek (MTK) should by no means be counted out, but the most advanced shipping to-date MediaTek Helio X10 only supports LTE Cat. 4 UL and DL data rates.  The MTK Helio X20, which features an astounding 10 CPU cores, will only support LTE Cat. 6 DL and LTE Cat. 4 UL, making us wonder whether 10 cores confers any real benefits other than bragging rights.  MediaTek excels at providing turnkey solutions for low- to mid-tier devices, but radio chipsets for high-mid- to premium smartphones require performance, features and usually some customization.  We do not expect MediaTek to offer todays’s latest, leading edge features and performance immediately, but instead to wait until these begin to move down into mid-tier devices.

Qualcomm has disappointed investors in terms of financial performance in the last two quarters, and has faced headwinds in China and with top customer Samsung, yet Qualcomm apparently has a six to 12 month lead on its LTE chip competitors in terms of performance, features and integration.  Operators do not publish the results of the qualification tests they run, which include testing mobile device power consumption, bit error rates, handover and call failure rates, but the number of LTE wins that Qualcomm continues to chalk up is a testament to the features and performance of its chips.

Consumers and suppliers alike will benefit from the rollout of the next versions of LTE-A, and Qualcomm looks to be in the best position to provide the mobile chipsets with the features and performance needed to meet consumer expectations.

For more about carrier aggregation, operators and chipsets, see the report Carrier Aggregation: Essential to Long-Term Operator and OEM Success .