Introduction, Streams, Single vs. multipoint, Roaming, Tri-band Extenders 8 Stream AC, 802.11ax, Choosing, Closing Start

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Introduction

Our 2017 guide said AC1900, AC1750 and AC1200 class routers were still the go-to choices for most buyers. These products are still likely to improve Wi-Fi range and speed if you're upgrading from an 802.11n class router. But if you want the best shot at improving Wi-Fi coverage and you're looking for a classic single point Wi-Fi router, our 2018 recommendation is to move up to four-streams.

This recommendation is reinforced by the results in our Router Ranker, which has generally shown four-stream products at the top of ranking order since we abandoned our system of ranking routers by "class" back in February 2017. I'll explain this further shortly.

The key issues affecting consumer Wi-Fi have also changed since last year, when we focused on assessing the impact of MU-MIMO, 160 MHz bandwidth, DFS, 802.11ad and "mesh" wireless. Those assessments and recommendations still stand, so the 2017 guide remains a good reference for those topics.

But industry changes over 2017 have bubbled up a new set of considerations in Wi-Fi router selection, which will be covered in this edition:

MIMO streams vs. Class

Single point vs. Multipoint (aka Router vs. Wi-Fi System)

Device roaming

Tri-band extenders

8 stream 11ac

802.11ax

As before, each topic will include background, bottom line and recommendation.

MIMO Streams vs. Class

Our Goodbye To Wi-Fi Router Classes explained our decision to de-emphasize the use of the Wi-Fi class system that served the industry well in the early days of 802.11ac. The class system provided a useful shorthand for differentiating product performance differances, even though it was primarially buyer bait to steer uninformed buyers toward buying products with the biggest number on the box (BNOB).

Unfortunately, the system collapsed on itself last year amid abuse and the introduction of new technologies that let Wi-Fi marketeers play fast and loose when toting up link rates to create artificially inflated class numbers.

In the end, the decision to move to a classless ranking system was a good thing, because it revealed something we should have realized sooner. A glance at today's Router Ranker shows products using four MIMO streams dominating the top ranker positions. This isn't because they have more power, because all products must obey transmit power limits, which include effective gains due to antenna design and even beamforming.

The reason for the higher ranking of four stream products is the increased transmit spatial multiplexing gain and receive diversity gain provided by using more MIMO streams. This effect helps client devices, regardless of number of streams they support.

This higher gain pushes the throughput vs. attenuation (or rate vs. range curve) higher and in some case farther out, as illustrated in the plot below that compares a NETGEAR four-stream router to a Linksys two-stream. In these plots, the higher the curve and the longer it stays high indicate better effective range. Although a four-stream product may not stay connected longer than a two or three stream, its ability to provide higher throughput at lower signal levels improves effective range, i.e. the area where you get throughput you can actually use.

Four vs. two stream rate vs. range comparison

You can still use class to tell products apart, but be careful. Some classes are easier than others to translate into number of MIMO streams. We have updated our Router and other Finders to include separate stream numbers for 2.4 and 5 GHz radios and number of radios, in addition to the "class" number assigned by the manufacturer. Here's a list to help translate the most commonly encountered classes to streams.

Two streams: AC1200, AC1300, AC2200 (tri-band)

AC1200, AC1300, AC2200 (tri-band) Three streams: AC1750, AC1900, AC2300, AC3200, AC4000 (tri-band)

AC1750, AC1900, AC2300, AC3200, AC4000 (tri-band) Four streams: AC2600, AC3100, AC3150, AC3900, AC5300 (tri-band), AC5400 (tri-band), AD7200

You'll need to read specs carefully for "AC3200" routers. AC3200 generally designates a router with three, three-stream radios (one 2.4 GHz, two 5 GHz). You will find, however, manufacturers also this class to inflate the class for routers supporting 160 MHz bandwidth, such as Linksys' WRT3200ACM, which has only two three-stream radios. As we noted in the 2017 guide, 160 MHz bandwidth provides no real benefit.

Bottom Line: MIMO streams are a more important factor than classes or box-front numbers when selecting routers or accees points. In general, the higher the number of streams, the better performance will be. Even with the one and two-stream Wi-Fi radios in most mobile devices, three and four stream routers can provide higher throughput over a wider range.

Single Point vs. Multipoint

Although it is a sponsored (paid) article for NETGEAR, the principles laid out in Solving the Wi-Fi Upgrade Dilemma: Router, Extender or Wi-Fi System are sound. Cramming too many nodes in too small a space may result in degraded performance due to co-channel interference. Since wireless backhaul requires nodes to be on the same channel, most Wi-Fi systems can't operate nodes on different channels, as is normally done with multi-AP systems using Ethernet backhaul.

Even tri-band Wi-Fi systems that have an extra 5 GHz radio usually set all fronthaul (client connection) radios to the same channel, due to lack of sophistication in backhaul management algorithms.

Bottom Line: More is not always better in the world of Wi-Fi. Multi-node Wi-Fi systems can definitely improve performance for larger and/or multi-floor homes. But single routers can work just fine or even better than Wi-Fi Systems for smaller spaces. Choose a multi node Wi-Fi System if you must, but experiment with the number of nodes if you have a smaller space to cover.

Device Roaming

When people started adding Wi-Fi extenders, many found their devices didn't reliably connect to them. Although multi-node Wi-Fi Systems may help improve Wi-Fi coverage, they may do nothing to help your devices roam more reliably.

This topic is covered in depth in How To Fix Wi-Fi Roaming.

Bottom Line: Devices are in charge for roaming. Don't fall prey to claims of "seamless" or "smooth" roaming for routers, extenders, APs or Wi-Fi systems. A lot depends on how cooperative your devices are. The older the device, the more likely it will "stick" to the first wireless connection it finds. And most routers don't support newer roaming assistance standards (802.11k,v,r) or other roaming assistance methods.

Tri-band Extenders

When NETGEAR debuted its Orbi Wi-Fi system, it looked like tri-band routers had finally become useful. Using the second 5 GHz radio as dedicated backhaul to a companion Wi-Fi extender provided real benefit; making it a four-stream radio was an even smarter move.

Unfortunately, you couldn't build a similar system from standard tri-band routers, because the firmware didn't allow one of the 5 GHz radios to form a bridge while the other remained free to support device connection.

While ASUS has decided to approach the problem of making tri-band routers more useful via its AiMesh initiative, NETGEAR and Linksys have created tri-band extenders in the form of NETGEAR's EX8000 and Linksys' RE9000.

NETGEAR EX8000 Tri-Band Wi-Fi Range Extender

The good news is that both products don't use WDS, so will work with any router. And thanks to their dual 5 GHz radios, they can form a dedicated backhaul link when used with tri-band routers, maximizing backhaul bandwidth.

Tbe bad news is NETGEAR has priced the EX8000 around $230, making it the most expensive Wi-Fi extender you can buy. Linksys has priced the RE9000 more reasonably at $170.

Bottom Line: If you like the router you have, or can't change it, but need more coverage or capacity, try a tri-band extender. While they're not cheap, their ability to form a dedicated backhaul with tri-band routers make them another useful tool in the Wi-Fi toolbox. Hopefully, TP-Link or maybe Tenda will come out with cheaper versions to broaden their appeal.