What about price, breadth of classification, accuracy?
In this fourth and final installment of our discussion about spectrum analysis and its relevance to Wi-Fi purchase decisions, let’s consider three final questions.
Do you pay a premium for SA?
It depends. Cisco, for example, charges about 50% more for certain APs that contain SA capabilities. Others, like Meru Networks, license the feature and/or require a separate appliance for running it. Still others, like Aruba, are “in between” in that if you’ve already licensed the company’s RFProtect capability for $70 per AP for security monitoring, the SA is included. If you don’t already have the license, you need to buy it.
MORE ON SPECTRUM ANALYSIS: Spectrum analysis: ‘Potato’ or ‘potahto’? | The ins and outs of spectrum analysis, part 2
Aerohive includes it as just another feature in its HiveManager software.
“We see spectrum as a diagnostic tool,” says Matt Gast, director of product management. “Cisco seemingly sees it as a whole reason to buy their $1,300 [Aironet 3500 Series] AP. If they believe spectrum is the most important feature, why didn’t they put it in their $800 [Aironet 1040] AP?”
That’s a fair question. Cisco provided its standard answer when I posed it, which, paraphrased, is that “Cisco offers different products for different ranges of customers and budgets.”
Sudheer Matta, senior director of product line management in the WLAN business unit at Juniper Networks, says that “one of the myths out there is that Cisco has a magical ASIC that sings and dances and no one else has it. That’s not true. The Cognio chipset [in Cisco gear] goes a long way, but the Atheros chipset [in other vendors’ systems including Juniper’s] is catching up. For half the money, I get 95% of the functionality” with the Atheros-based solutions, he says.
How many devices can it classify and is it accurate?
The Wi-Fi vendors’ SAs appear to support anywhere between eight and 20 device classifications. The more granular the SA resolutions, the more devices you can detect. For example, Bluetooth uses 1MHz of spectrum, so your SA needs to see down to 1MHz to detect it. Aerohive’s Gast estimates that you can see most interferers with an SA that drills down to half a megahertz.
Motorola’s Nathan Rowe, senior manager of product planning, adds that for enterprises, “being able to justify a high-end AP with SA resolution down to a couple kilohertz is getting harder and harder.”
Juniper’s Matta doesn’t think accuracy is an issue. “They detect devices, we detect devices, we all classify. The probability of missing an interferer is low” with anyone’s system, he says.
Which WLAN vendors offer built-in SA?
The following are among the Wi-Fi vendors that have added spectrum analysis capabilities to their Wi-Fi systems: Aerohive (part of HiveManager 4.0 software, announced in May); Aruba (Spectrum Analysis Module), Cisco (CleanAir), Juniper (WLA-522), Meraki (AutoRF), Meru Networks [E(z)RF Spectrum Manager] and Motorola (AirDefense Spectrum Analysis Module).
