Qualcomm said it's extending its LTE product to include unlicensed spectrum (LTE-U). The technology has already been integrated into its latest small cell products and RF transceivers for mobile devices. Qualcomm also announced that it successfully completed over-the-air testing to prove co-existence between multiple LTE-U and Wi-Fi access points in the unlicensed spectrum under extreme load conditions. Qualcomm will show the new products with a number of LTE-U demonstrations at Mobile World Congress.
LTE-U is designed to augment nework capacity by using channels in the less-crowded 5 GHz unlicensed bands, normally used for Wi-Fi. LTE-U uses several coexistence features to support fair share use among the multiple users and technologies that access those bands.
Qualcomm's products using the technology include the FSM99xx, a family of small cell SoCs available in the second half of 2015. Theese integrate Qualcomm's 3G and 4G and support its VIVE 802.11ac/n Wi-Fi. Qualcomm also announced the FTR8950 as the first dedicated RF product for small cells designed to meet the requirements of LTE-U operation and network listen in unlicensed 5 GHz bands. This is a successor to the FTR8900 RFIC and supports features such as digital pre-distortion and dedicated network listen.
For mobile devices using LTE-U, the company presented the WTR3950 RF solution. The 28 nm RF transceiver will be commercially sampling in the second half of 2015.The WTR3950 pairs with the WTR3925, the first 28 nm RF for single chip Cat 6 carrier aggregation, to support up to 3x20 MHz carrier aggregation across licensed and unlicensed spectrum.
Qualcomm said its testing showed that LTE-U can not only provide superior performance than either LTE or Wi-Fi used individually, but fairly coexists with Wi-Fi. In many cases, shifting traffic from Wi-Fi to LTE-U can actually improve performance for Wi-Fi users, due to the efficient way that LTE uses the unlicensed spectrum.
Testing scenarios included both “adaptive duty-cycle” based coexistence which is suitable for commercial LTE-U deployments in countries such as the US, China and Korea using LTE Release 10 and beyond, as well as Listen Before Talk (LBT) based techniques that are proposed through a work item for an upcoming release of the LTE standard, Release 13, which is expected to define a version of LTE-U known as Licensed-Assisted Access (LAA), suitable for deployments in other regions such as Europe and Japan.
