5G uplink trial makes waves with addition of third transmit antenna

Samsung Electronics and MediaTek have successfully conducted 5G standalone (SA) uplink tests, using three transmit (3Tx) antennas instead of the typical two, to demonstrate the potential for improved upload experiences with current smartphones and customer premise equipment (CPE).

The 2CC carrier aggregation (CA) tests conducted at Samsung's laboratory in Korea harnessed the company's 5G network portfolio, including C-Band massive multiple input, multiple output (MIMO) radios, virtualized distributed unit (vDU) and core.

MediaTek's test device, featuring its latest M80-based CPE chipset, achieved results with one uplink channel at 1,900MHz and another at 3.7GHz, supplemented by an additional uplink flow using MIMO on 3.7GHz.

Together, the companies achieved a peak throughput rate of 363 Mbps, which they said approached the “theoretical” peak uplink speeds possible with 3Tx antennas.

While the partners acknowledged that current smartphones and CPEs can only support two antennas, they said the successful uplink trial indicates the potential of supporting those devices with three antennas in the future.

Dongwoo Lee, head of technology solution group at Samsung Electronics, called the test an industry “milestone” and touted the transformative capability of faster uplink speeds to enhance user experiences.

“With demands on mobile networks rising, enhancing upload performance is essential to improving consumer and enterprise connectivity, as well as application experiences,” said Will Townsend, VP and analyst at Moor Insights & Strategy.

“Samsung and MediaTek have achieved an important 5G Standalone milestone in a demonstration which underscores a tangible network benefit and does so in a way that can help operators maximize efficiency.”

Until lately, most talk about 5G SA industry firsts have surrounded the downlink. But the increasing demand for uplink performance, driven by activities such as live streaming, multiplayer gaming and video conferences, has underscored the importance of fast and reliable upload speeds.

This year other players in the industry have completed their own uplink tests focused on enhancing performance speeds.

AT&T in April announced a 5G SA uplink 2-carrier aggregation data connection in the U.S. using Nokia’s 5G AirScale portfolio and MediaTek’s 5G mobile test platform, for example.

Carrier aggregation refers to the combination of different frequency bands to get more bandwidth and capacity. In that case, AT&T aggregated 10 MHz of its low-band n5, or 850 MHz, and a couple different scenarios – 40 MHz and 70 MHz – with mid-band, or n77/C-band at 3.7 GHz.

Compared to low-band n5 alone, AT&T saw a 100% increase in uplink throughput by aggregating the 850 MHz with the C-band, and the carrier reported a 250% increase aggregating 100 MHz of n77.

In May, T-Mobile worked with Nokia and Qualcomm to reach uplink speeds over 200 Mbps in a 5G data call using uplink carrier aggregation.

Working in the field rather than a lab, T-Mobile used a test smartphone with Qualcomm’s Snapdragon 5G Modem-RF System and gear from Nokia to achieve a top uplink speed of 207 Mbps, which it said at the time is the fastest ever recorded using sub-6 GHz spectrum.

Ericsson and MediaTek in May said they set a new 5G upload record of 440 Mbps using uplink CA, using the former’s radio access network (RAN) Compute Baseband 6648 and a mobile device using a MediaTek Dimensity 9200 flagship 5G smartphone chipset.

However, the Samsung collaboration with MediaTek is so far the only uplink trial to explore the use of three antennas.