Ac87u four antennas - why?

[paraplu]

Puzzling:
My AC wireless client devices are all having a max of 2 antennas. The AC87U has 4 dual-band antennas. What is the advantage of these 4 antennas, instead of 2? Does someone know if the Asus is doing some tricks e.g. load balancing or location correlation?

 

[red_pope]

I believe the correct answer would be performance, stability, beam forming and endurance.
I don't own one, but my neighbor does! He's SSDI broadcast at approximately 270 feet from their house with full 4 bars to my home kitchen.

Groundbreaking Wireless Performance
Enjoy a new level of wireless performance, with 2334Mbps of combined 802.11ac and 802.11n bandwidth. With class-leading speeds of up to 600Mbps on the 2.4GHz band – thanks to Broadcom® TurboQAM™ technology – and up to 1734Mbps concurrently on the 5GHz band, which is even faster than the latest tri-band 3 x 3 routers, RT-AC87U leaves the competition standing.

At the Forefront of Technology – RT-AC87U doesn't lead others, it dominates, offering the best current-generation performance for all your laptops, smartphones and other wireless devices.

Unrivaled Signal Coverage
Boasting a true four-stream, four-antenna (4 x 4) design, RT-AC87U gives you up to 465 square meters (around 5,000 sq. ft.) of wireless coverage. That's 33% more than the latest generation tri-band routers, making it the ideal choice for large homes and multi-floor buildings. Thanks to AiRadar beamforming and unique multi user-MIMO (MU-MIMO) technology, the more devices you use the more the throughput increases.

• Multi-user MIMO Technology – RT-AC87U is the first router to support MU-MIMO technology for massively-improved performance in multi-device environments. MU-MIMO can communicate at full 801.11ac speeds with multiple compatible devices, unlike single-user MIMO (used in all existing dual- and tri-band routers), which communicates with only one device at a time.

AiRadar Beamforming – ASUS AiRadar intelligently strengthens wireless connectivity using 802.11ac universal beamforming technology, high-power amplification and exclusive ASUS RF fine-tuning. This gives RT-AC87U up to 33% better coverage than 3-stream antenna designs. In real-world tests, RT-AC87U lets you stream two 4K videos flawlessly at its maximum range.

For further answers search for it at the ASUS web site.

 

[LoneWolf]

First off, your AC clients are two-stream setups, thus their two antennas. The RT-AC87U supports three-stream wireless for your 802.11n clients that support it (the Intel 4965AGN, 5300N, and 6300N are the chief examples), for a maximum of 450Mbps on wireless-N. There are very few three-stream 802.11AC clients out there; the only one I'm aware of is ASUS' PCE-AC68 desktop wireless card, but you could also get three-stream AC if you were bridging two RT-AC87U units.

The fourth antenna is because the RT-AC87U is a Wave 2 device that supports MU-MIMO (or at least, will when the firmware is updated to enable it) which allows better throughput under the load of multiple wireless devices. Note that wireless clients must support MU-MIMO as well for this to work, meaning that at this time, you're unlikely to see any improvements, as few if any AC wireless cards support the standard.

 

[RMerlin]

The Rt-AC87 is actually a 4 streams router, supporting up to 1700 Mbps on the 5GHz band with a compatible client. Hence the four antennas.

Sent from my Nexus 9 using Tapatalk

 

[zerodegrekelvin]

First off, your AC clients are two-stream setups, thus their two antennas. The RT-AC87U supports three-stream wireless for your 802.11n clients that support it (the Intel 4965AGN, 5300N, and 6300N are the chief examples), for a maximum of 450Mbps on wireless-N. There are very few three-stream 802.11AC clients out there; the only one I'm aware of is ASUS' PCE-AC68 desktop wireless card, but you could also get three-stream AC if you were bridging two RT-AC87U units.

The fourth antenna is because the RT-AC87U is a Wave 2 device that supports MU-MIMO (or at least, will when the firmware is updated to enable it) which allows better throughput under the load of multiple wireless devices. Note that wireless clients must support MU-MIMO as well for this to work, meaning that at this time, you're unlikely to see any improvements, as few if any AC wireless cards support the standard.

I just want to add that the PCE-AC68 3x3 card is using the same Broadcom chipset as the one used for the RT-AC87U. The massive heatsink is typically a sign Broadcom chip is underneath. QCA 3x3 chip runs much cooler. The heat from the BRCM chip does not come from PowerAmplier, but from the BRCM wifi chip.