It’s Here: Triple-Stream 802.11n MIMO

Meraki MR24

Figure 1: Meraki MR24

Everyone at Meraki is extremely excited about the newest member of our enterprise 802.11n access points: the top-of-the-line Meraki MR24, available now. The MR24 is our fastest and most powerful AP yet, bringing unmatched throughput and capacity with its triple-stream 802.11n MIMO in dual-concurrent radios, and still keeping the incredibly sleek profile Meraki’s access points are known for, all without breaking the bank.

The jump from 802.11a/b/g to 802.11n has been instrumental in increasing Wi-Fi throughput for users. A large chunk of the throughput gains comes from implementing MIMO. The 802.11n standard allows for two-, three-, and four-stream MIMO, but so far only two-stream MIMO access points and clients have been available, leaving a lot of capacity on the table, and leaving networks strained as they attempt to serve a higher density of clients. We’re changing that with the new Meraki MR24 access point.

A look at today’s access points

802.11n MIMO is most commonly offered today as a dual-stream implementation, usually in 2×2 mode. As discussed in a previous blog post on MIMO, this means the system has two transmit antennas and two receive antennas. Nearly every major wireless enterprise and consumer-grade access point vendor offers 802.11n products with 2×2 MIMO. This allows manufacturers to specify maximum throughput rates of up to 300 Mbps (per radio).

Wait – aren’t there some 3×3 access points already available?

A few vendors offer enterprise-class access points labeled as having 3×3 MIMO radios. This is technically correct, but often misleading. While yes, those access points do have a 3×3 configuration with three transmit antennas and three receive antennas, nearly all 3×3 access points only support two streams even with three transmit antennas. A quick peek at the data sheet almost always reveals that, in fact, only two streams are supported. The reason to have a third antenna, even when having only two streams, is to increase the diversity of the signal. This means the reliability and range can be moderately improved. But the third antenna does not add an additional, parallel, full-rate spatial multiplexing data stream. So it’s important to check the maximum supported data rate of the access point.

Check the speedometer

A triple-stream 3×3 MIMO radio will support up to 450 Mbps. If the maximum data rate listed is only 300 Mbps, this almost certainly means that only two MIMO spatial streams are implemented. Note: this is the per radio data rate. Many access points have two radios. If each has a maximum capacity of 300 Mbps, the aggregate access point capacity is 600 Mbps – but this does not mean it is superior to a triple-stream implementation. Any single client, even a 3×3 client, will only ever experience the maximum data rate of the single radio, since it cannot tune to and receive two channels simultaneously. There are several advantages of having dual- and triple-radio access points, but increased single-client data rates is not one of them.

Table 1 shows the maximum supported data rates of 802.11n MIMO and the aggregate rates possible with dual radio access points.

802.11n MIMO data rates

Table 1: 802.11n MIMO data rates

Meraki MR24: clocking in at a total of 900 Mbps

The Meraki MR24 marks another milestone in the evolution of Wi-Fi – the arrival of triple-stream 802.11n MIMO access points. The 300 Mbps supported by 2×2 MIMO may sound pretty speedy, but many networks and users are still hungry for even more. The Meraki MR24 supports triple-stream 3×3 MIMO and has a maximum data rate of 450 Mbps per radio. It has two of these radios inside, which means the aggregate throughput of the access point is 900 Mbps. That’s right – approaching Gigabit rates over the air. This also means a higher number of clients, up to 50% more compared to 2×2 MIMO, can be simultaneously supported by the access point, thus alleviating the strain of access points struggling to support dozens and hundreds of clients in a wireless network.

What’s in the secret sauce?

It’s no secret our engineering teams are incredibly sharp. It’s not enough to take a radio chipset and solder it onto a board. The radio has to be optimized, the antennas must be designed to have the right electrical characteristics to support three Tx and three Rx chains simultaneously and fit into the hardware enclosure, and the entire access point has to be beefed up to support the higher data rate of 450 Mbps. The Meraki MR24 is a dual-radio access point, so this all has to be done to support two radios and the 900 Mbps aggregate data rate.

Meraki MR24

Figure 3: Meraki MR24

All of this still fits into the tight power budget of 802.3af, even when running the dual-concurrent radios with triple-stream MIMO. And though there are six antennas inside (yep – that’s the antenna in the cut-away image), the AP still has an incredibly sleek profile – only 1.5 inches (38 mm) thick.

And that’s not all. The MR24 supports Meraki’s complete feature set and award winning cloud-based management. The MR24 provides:

  • Advanced wireless security with an integrated policy firewall, NAC, Teleworker VPN, and guest access
  • Layer 7 application traffic shaping and analysis
  • AutoRF cloud-based optimization with spectrum analysis
  • Built-in client location services
  • High-performance, self-optimizing mesh networking
  • Automatic provisioning, management, and monitoring from the cloud

Wireless networks have never been as fast as they are now with the new Meraki MR24. Triple-stream 802.11n MIMO and dual-concurrent radios now let wireless networks approach Gigabit speeds. At a price of $1199, it doesn’t have to cost a gigabuck, either. You can find more details about the Meraki MR24 on our website. If you’d like to try out a few MR24 APs, we’d love for you to give us a call.