As always with wireless, the same old chestnuts of range, reliability and interference will continue to cause headaches so we shall still need spectrum analysers of course.

Full 802.11 Capture
Wireshark Integration
Open API
Multi-channel Monitoring (requires 2+ adapters)
Packet Transmission
External Antenna Connector			2 connectors
Form Factor	USB	USB	USB
Frequency Bands	b/g	b/g	a/b/g/n

How AirPcap Operates
All AirPcap adapters can operate in a completely passive mode. In this mode, the AirPcap adapter will capture all of the frames that are transferred on a channel, not just frames that are addressed to it. This includes data frames, control frames and management frames. When more than one BSS shares the same channel, the AirPcap adapter will capture the data, control, and management frames from all of the BSSs that are sharing the channel within range of the AirPcap adapter.

AirPcap adapters capture traffic on a single channel at a time. The channel setting for the AirPcap adapter can be changed using the AirPcap Control Panel, or from the “Advanced Wireless Settings” dialog in Wireshark. Depending on the capabilities of a specific AirPcap adapter, it can be set to any valid 802.11 channel for packet capture.

The AirPcap software can be configured to decrypt WEP-encrypted frames. An arbitrary number of keys can be configured in the driver at the same time, so that the driver can decrypt the traffic of more than one access point simultaneously. WPA and WPA2 support is handled by Wireshark.

Multiple Channnel Capture
When monitoring on a single channel is not enough, multiple AirPcap adapters can be plugged into your laptop or a USB hub and provide industry-leading capability for simultaneous multi-channel capture and traffic aggregation. The AirPcap driver provides support for this operation through Multi-Channel Aggregator technology that exports capture streams from multiple AirPcap adapters as a single capture stream. The Multi-Channel Aggregator consists of a virtual interface that can be used from Wireshark or any other AirPcap-based application. Using this interface, the application will receive the traffic from all installed AirPcap adapters, as if it was coming from a single device. The Multi-Channel Aggregator can be configured like any AirPcap device, and therefore can have its own decryption, FCS checking, and packet filtering settings.

A lot of the time passively avoiding interference is all that is needed to make your WLAN run better. Just move to a channel that is less affected by RF from Wi-Fi, cordless phones, etc., and your interference-caused throughput and connectivity problems go away. But sometimes — as is becoming more and more apparent in the 2.4 GHz band — there are not enough open channels to go around and no amount of avoidance will be sufficient to make your network interference free. There are just too many devices sharing the same swath of unlicensed spectrum to allow everything it’s own space for a good, solid wireless connection.

So, what to do?

If you could just find these transmitters then you could eliminate them, or move them, or at least figure out how they fit into sharing the available spectrum resources. But that’s just the problem, right? Any number of things could be the culprit as just about *everything*, both consumer and commercial devices, uses the 2.4 GHz band these days. Plus, a lot of the time these devices are hidden from plain sight making the job even harder.

Here’s where Device Finder Directional Antenna comes in. With a 60 degree horizontal beamwidth, and a 7 dBi gain this new accessory blocks out “ambient” RF noise from most of the area surrounding you, while giving gain to the area where you are pointing. When used in conjunction with Device Finder mode in Chanalyzer Pro, all it takes is to click-drag the over the spectrum graph to highlight the target signal. Then, it’s just a matter of watching the red line increase or decrease in amplitude as you walk and point.

Once you find the device, you decide what to do with it. A lot of the time this means trading-out that cheap-o 2.4 GHz cordless phone for a 1.9 GHz DECT model, or replacing the obsolete wireless camera you discovered with a more modern, non-interfering one. Sometimes, it takes more creative actions and a measure of compromise must be taken. But, at a minimum, you will have all the information you need to manage your wireless environment and you will know with certainty which devices are sharing the band.

It’s all about knowing. Chanalyzer Pro and Device Finder Directional Antenna clue you in on what’s happening in your wireless landscape and lets you actively control what’s using your spectrum resources.

By Trent Cutler (Metageek “Utility Player”), reproduced with permission

Wi-Spy, on the other hand, uses a narrowband RF receiver to scan across the RF band in tiny steps. These steps can be anywhere from 25 KHz to 400 KHz wide. While Wi-Spy can’t scan at arbitrary resolutions like an Agilent spectrum analyzer, it has about a dozen resolution bandwidth settings ranging from about 50 Khz to over 600 KHz (exact values depend on Wi-Spy model and RF band). Currently Chanalyzer automatically adjusts the Wi-Spy settings when you change frequency bands, but finer-grained control is coming soon in Chanalyzer Pro and Chanalyzer Lab (currently in private beta).

Here are screenshots showing the 2.4 GHz band at the smallest and largest step sizes of the Wi-Spy 2.4x.

The variable step size and resolution bandwidth allow Wi-Spy to be optimized for different bandwidths and signal types from 802.11n to Bluetooth and Zigbee. The default Wi-Spy settings scan the 2.4 GHz band using a step size of 333.3 KHz. This is ideal for detecting Bluetooth, which uses 1 MHz channels. For scanning the entire 5 GHz band, Wi-Spy DBx uses a large step size to decrease the sweep time (time it takes for each scan of the RF band). As you zoom into smaller sections of bandwidth, Wi-Spy shrinks its step size to provide higher resolution. For detailed Wi-Fi scanning, Wi-Spy can be configured to scan at six times the resolution of the channel subcarriers!

Here’s a high resolution scan of a 40 MHz 802.11n channel.

This powerful hardware configurability is one of the many reasons why wireless professionals choose Wi-Spy more often than any other spectrum analyzer.

By Ryan Woodings (Metageek “Chief Geek”), reproduced with permission

With Chanalyzer Pro and Wi-Spy 2.4x or DBx you can:

• Quickly build powerful Wi-Fi reports.
• Find and Identify sources of Interference.
• Record Wi-Fi and Spectrum Data.
• See how bad the interference was – when it occurred.
• View a single channel in high resolution
• Increase 5GHz 802.11n hardware installations

Enjoy the satisfaction of a nearly perfect WLAN implementation with Chanalyzer Pro spectrum analysis software. Chanalyzer Pro identifies devices in the spectrum, helps you track them down, and produces customizable Wi-Fi reports.

Especially useful for optimizing Wi-Fi performance, Wi-Spy makes the invisible visible and enables you to defeat wireless interference emitting from any source, including cordless phones and wireless cameras.