Broadcom has that BCM4389 presented a smartphone chip for Wi-Fi 6E – i.e. 802.11ax with 6 GHz as the third band. The BCM4389 follows the widely used BCM4375, which can be found in many current smartphones. The new chip expands the 2.4 and 5 GHz band by one with 6 GHz, which significantly increases the data rate. Broadcom also has the BCM4389 produced with a finer build, which makes it significantly more economical.
If the BCM4375 was still a 28 nm design, the BCM4389 is manufactured in a 16 nm node. According to Broadcom, the power consumption during operation drops from 2.5 amps to half an ampere – the efficiency increases drastically. The throughput also increases significantly, since in addition to frequency bands with 2.4 GHz and 5 GHz, there is also that with 5 GHz and the seven instead of five channels are designed wider – they now work at 160 MHz instead of 80 MHz.
The peak rate should be up to 2.1 GBit / s instead of up to 400 MBit / s. In theory, the BCM4375 achieves up to 2.63 GBit / s thanks to 1024-QAM modulation, the orthogonal frequency division multiplexing (OFDMA) and 2×2-MIMO – but practically through overhead, but less. In addition to the doubled data rate and twice the channel width, the BCM4375 should also halve the latency for connections. Optimizations for Bluetooth 5 should increase the connection speed (pairing) and improve the audio quality for wireless headsets.
BCM4389 at a glance (Image: Broadcom)
Wi-Fi 6E is the first expansion of the WLAN spectrum in 17 years; after all, the 5 GHz band was last officially expanded in 2003. The Wi-Fi Alliance wants to take into account the massive increase in the number of client devices with Wi-Fi 6E and thus the expansion of the spectrum used. The BCM4389 should therefore soon be used in smartphones.