Until now, SmallNetBuilder has taken a technical approach to identifying wireless product families. We have referred to the number of streams a product uses, i.e. N1, N2, N3, identified the number of radios a product has and noted which band(s) they operate on. While technically correct, it’s not easy for folks who don’t follow the industry closely to parse. So it is of little help to less technically-minded consumers reading SNB reviews and trying to make purchase decisions.
This approach is also is out of step with the nomenclature used by product manufacturers. The industry has generally adopted NXXX and ACXXXX nomenclature, i.e. N300, N900, AC1750. This is not "official" nomenclature supported by either the IEEE or Wi-Fi Alliance. So, for lack of a better term, I am calling it the wireless “class”.
While manufacturers haven’t all settled on the same class numbers for draft 11ac products, the terms are generally uniformly applied for N products and make sense for router and access points.
Table 1 shows the base numbers that are used to come up with the current "N" and "AC" class designations. The numbers shown are the maximum link (connection) rates that each product type can support. Link rates are not the actual throughput that your wireless connection will produce. They are more an indication of the technology used in the product and only good as a relative performance indicator. Think of the link rates like number of cylinders in a car and you’ll have the right idea.
| Number of Streams | 802.11n 20 MHz mode (1 channel) |
802.11n 40 MHz mode (2 channels) |
802.11ac 80 MHz mode (4 channels) |
|---|---|---|---|
| 1 | 65 | 150 | 433 |
| 2 | 130 | 300 | 867 |
| 3 | 225 | 450 | 1300 |
Table 1: Stream / Channel width / Maximum Link Rate summary (Mbps)
It’s valid for simultaneous dual-band routers to add together the maximum link rates of each radio to get the “N” number. For example, "N900" routers are capable of supporting maximum link rates of 450 Mbps on both radios at the same time. "N750" routers support 450 Mbps on one band and 300 Mbps on the other. But there is no way of knowing from the "N750" number which band supports the higher link rate.
The problem comes for dual-band devices that are not capable of simultaneous operation on both bands. A dual-band wireless adapter or single-radio repeater capable of 450 Mbps on each band only works in one band at a time. So should these devices be referred to as N450, which is technically more correct? Or should we use N900, which might allow consumers to more easily match client devices and router classes by looking at product boxes?
AC’s The Rub
Before you answer, consider that the situation is complicated by 802.11ac devices. All current and recently announced ac devices are dual-band. (I have heard that there could be non-standard 5 GHz only 11ac devices at some point, but let’s hope they don’t come to pass.) Unlike N devices, the maximum link rates for AC devices are not the same for both bands.
For example, and referring to Table 1 above, the lowest performance 1X1 11ac adapter (1X1 means one transmit and one receive stream in the radio) has a maximum 5 GHz link rate of 433 Mbps and a maximum 2.4 GHz rate (40 MHz mode column) of 150 Mbps. So should we class this device as an AC433? Or should we copy what Linksys has done with its recently-introduced draft 11ac USB adapter and refer to it as AC580 (433 + 150, rounded down to a more marketing-friendly even number)?
We have decided to use the highest single rate supported on single-band devices. So AC devices and repeaters would be AC433, AC867 or AC1300, and N devices will be dubbed N150, N300 or N450, depending on whether they are 1×1, 2×2 or 3×3 devices. If a repeater or range extender can operate in both bands simultaneously, the router naming rules will apply, i.e. the maximum link rates of each band will be added together.
Table 2 shows the class designations for routers and access points or dual-radio wireless repeaters / range extenders that are capable of simultaneous band operation.
| "Class" designation | 2.4 GHz N Radio Maximum Link Rate (Mbps) |
5 GHz AC Radio Maximum Link Rate (Mbps) |
|---|---|---|
| AC1750 | 450 | 1300 |
| AC1600 | 300 | 1300 |
| AC1310 | 450 | 867 |
| AC1200 | 300 | 867 |
| AC750 | 300 | 433 |
| AC580 | 150 | 433 |
| N900 | 450 | 450 |
| N750 | 450 | 300 |
| N750 | 300 | 450 |
| N600 | 300 | 300 |
Table 2: Proposed router class (dual-radio) summary
Table 3 shows the class designations for client devices or single-radio wireless repeaters / range extenders that are capable of operating in only one band at a time.
| "Class" designation | 2.4 GHz N Radio Maximum Link Rate (Mbps) |
5 GHz Radio Maximum Link Rate (Mbps) |
|---|---|---|
| AC1300 | 450 | 1300 |
| AC867 | 300 | 867 |
| AC433 | 150 | 433 |
| N450 | 450 | 450 |
| N300 | 300 | 300 |
| N150 | 150 | 150 |
Table 3: Proposed device class (single radio) summary
There was only one naming collision between the two charts: AC1300. D-Link slapped the AC1300 class on its DGL-5500 Gaming Router introduced at CES. This product has an odd mix of three-stream 2.4 GHz and two-stream 5 GHz radios, which I’m not sure will be a popular configuration. Since three-stream bridges will be more common, I’m leaving the round-numbered AC1300 class to indicate single radio products. I bumped the number of dual-radio products in this class to AC1310, which is closer to the 1317 Mbps total anyway.
We’ll be changing over to this new naming system soon in the Wireless and Router Finders. We hope it will make products easier to find. This change will enable some new Charts features that we have in the works, too.
What do you think? Please let us know over in the Forums, or drop a line to [email protected] to weigh in. Thanks!