Moving to the next stage of adoption

To address lower tiers of the smartphone market, a number of chip companies are now combining multimode 2G/3G/LTE modems with applications processors to provide lower cost integrated smartphone platforms. These devices will be a requirement for wireless network operators to expand LTE adoption beyond their leading-edge customers. Verizon Wireless has said they intend to make LTE a requirement on nearly all future smartphones that they support, but currently only 5 percent of their subscribers are using LTE.

Introducing a new processor

Renesas Mobile Corporation showed demonstrations of their new communications processor at MWC, the MP5232. The company was able to combine the functions of their MP5225 application processor, and SP2531 triple-mode (4G/3G/2G) modem, into a single 28 nm SoC. The MP5232 modem supports all Category 4 (150 Mbps download, 50 Mbps upload) Frequency Division FD-LTE Bands, while the application processor includes dual ARM Cortex-A9 cores with a SGX graphics processor, which Renesas Mobile licenses from Imagination Technologies. Renesas is planning to have a reference design platform for the MP5232, running the latest Android Ice Cream Sandwich operating system, available by the end of Q1 this year.

Next stop: China

LTE chip suppliers are also directing more of their design efforts toward China, where Time Division TD-LTE is under development. Marvell Technologies Group showed their latest multimode modem chip, the PXA1802, in a smartphone reference platform that includes their PXA2128 – a unique 3-core applications processor. The processor integrates dual ARMv7 cores that are comparable to the Cortex A9, combined with a third, smaller core for low power operation. The PXA1802 supports both Category 4 TD-LTE and FD-LTE, with a specified maximum download (DL) rate of 150 Mbps, and an upload (UL) rate of 50 Mbps. Marvell says that the emphasis in their design of the PXA1802 is on TD modes, and the device will support 4G-to-3G handoff from TD-LTE to Time Division Synchronous Code Division Multiple Access (TD-SCDMA), specifically for China Mobile.

The race for first

As the market for LTE heats up, so do the claims for “first” and “fastest” amongst chip and handset manufacturers. Huawei announced what they claimed is the “World’s Fastest Smartphone” at MWC, the Ascend D quad. The Ascend smartphones are powered by a quad ARM Cortex-A9 core application processor from Huawei subsidiary HiSilicon, which also laid claim at MWC to being first to offer a multimode TD-FD modem chip for LTE applications. HiSilicon would not release many details at this point, other than to say their Balong 710 modem supports Category-4 LTE in FDD mode, with identical specifications to Marvell and Renesas, while adding support for TD-LTE mode with up to 112Mbit/s downlink and up to 30Mbit/s uplink.

Qualcomm may dispute HiSilicon’s claims to be first with a multimode LTE device, since the company also announced their next generation of Gobi modem chipsets at MWC, the MDM9225 and MDM9625. Besides supporting both TD- and FD-LTE, Qualcomm moved the bar up a notch by making their own “first” claim: “the first to support both HSPA+ Release 10 and the next-generation of the LTE mobile broadband standard, LTE Advanced.” High-Speed Downlink Packet Access, or HSPA/HSPA+, is an enhanced 3G technology which U.S. carriers AT&T and T-Mobile have relabeled as 4G, in order to keep up in the marketing wars while they lag behind Verizon Wireless in LTE deployment. Developers of HSPA+ expect to achieve 168 Mbps peak theoretical downlink and more than 20 Mbps uplink speeds in Release 10. While referring to LTE Category 4 as LTE-Advanced, Qualcomm does add a key capability for migration up to higher performance levels of the 4G standard – carrier aggregation. Carrier aggregation is important for increasing bandwidth by enabling operators to combine multiple radio channels to increase user data rates, especially critical to operators who lack 20 MHz of continuous spectrum.

To move up to higher-performance LTE-Advanced networks, operators will need more powerful Enhanced Node B (eNodeB) base stations, equipped with processors that can handle the higher data rates and more complex signal processing and communications requirements. Not to be outdone, chip vendors were ready with their MWC announcements of firsts in this space as well. Freescale Semiconductor claimed to have developed the industry’s highest performance macrocell base station on a chip, with their announcement of the B4860. The 28 nm B4860 will extend Freescale’s line of QorIQ Qonverge basestation on a chip SOCs, from their 45 nm PSC9132/31/30 for femto and pico cells. The B4860, supports three 20 MHz sectors of LTE for metropolitan applications with hundreds or thousands of users.

Texas Instruments has also upgraded their silicon technology from 40 nm to 28 nm, which they will use to manufacture the new TCI6636 base station on a chip. A first for TI, with the TCI6636, is the semiconductor industry’s first quad implementation of the latest ARM Cortex-A15 cores. The company’s previous designs were the 40 nm ARM Cortex A8-based TMS320TCI6612 and TMS320TCI6614. TI designed the TCI6636 for the high-end of the small cell market, or so that designers can group three chips together to make a macro cell. TI says that the TCI6636 will support Category-7 LTE (300 Mbps downlink, 150 Mbps uplink), and LTE-Advanced with 40 MHz channel bandwidth and carrier aggregation, for up to 256 users.

This is only the beginning

With LTE adoption still in the early days here in the U.S., which leads the rest of the world in 4G rollout, semiconductor vendors are preparing chipsets to move performance up to even higher levels of LTE-Advanced. In just over a year, carriers such as Verizon Wireless have transformed their 3G business to 4G, and supported by the chip and device manufacturers, eliminated pricing premiums that would inhibit consumers from selecting LTE handsets. We will see very quickly if the networks can support the additional load as operators move out of the early adopter phase. It will also become clear whether predictions of heterogeneous networks of small and large cells finally come to fruition, powered by base station on a chip SoCs like those announced by TI and Freescale at MWC.

For more information, contact Mike at mdemler@opensystemsmedia.com.