Updating openwrt

To distract buyers from the absence of MU-MIMO, router makers chose to ship the new Broadcom radio in "tri-band" designs, creating gargantuan, expensive, eight-antenna AC5300/AC5400 class routers like NETGEAR's R8500 Nighthawk X8 and ASUS' RT-AC5300.

The hope was that folks would get some benefit from the second 5 GHz radio and forget about the non-functional MU-MIMO.

But I'm told the Pixel has Qualcomm MU-MIMO Wi-Fi buried inside and the Samsung S7 has Broadcom.

updating openwrt-87

multiperf3 is a variant of iperf3 that can run simultaneous tests to multiple iperf3 servers. When MU-MIMO was enabled on the router, the Pixel's link rate stayed the same, but the Samsung's dropped to the 433 Mbps indicative of a single-stream 802.11ac connection. With MU disabled on the R7800, total average throughput is around 616 Mbps and with it enabled, it's around 760 Mbps, a gain of about 23%.

The test was simple: The first screenshot shows the phones associated with the R7800 that had MU-MIMO disabled. Given the 50% reduction in link rate, we'd expect the S7's throughput to be cut in half, right? This is far from the "up to 3x faster" Qualcomm claims in its MU-MIMO promotional material, but at least still a gain.

Some of these still await firmware upgrades to enable MU-MIMO.

AC2600 class routers with Qualcomm's 4x4 radio were next to market in mid-2015.

It turns out that Broadcom's problems were not all in firmware, however.

I learned late last year that some manufacturers have quietly been phasing a BCM4366 C0 version of Broadcom's 4x4 radio So C into production without any visible model number or version change to products.

Even when lower cost Broadcom-based dual-band AC3100/AC3150 class routers like ASUS' RT-AC88U and RT-AC3100 started shipping a few months later, working MU-MIMO firmware was still MIA.

And when we finally tested a Broadcom MU-MIMO router with allegedly working MU-MIMO firmware in the form of TP-Link's Archer C3150 in August 2016, we found MU-MIMO performance so poor, that it was essentially non-functional.

It's interesting that TP-Link's Class II Change letter refers to the previous BCM4366 B1 as "SU-MIMO". phones to support MU-MIMO were Google Nexus and Samsung's Galaxy S6.

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