In wireless networks, particularly short-range wireless networks such as IEEE 802.11 wireless local area networks (WLANs), the radio frequency band in which the wireless network operates is a frequency band that is shared with other wireless applications. For example, an IEEE 802.11 WLAN operates in either the 2.4 GHz unlicensed band or one of the 5 GHz unlicensed bands in the U.S. Other non-IEEE 802.11 WLAN devices operate in these frequency bands, including devices that operate in accordance with the Bluetooth® protocol in the 2.4 GHz band, cordless telephones in the 2.4 and 5 GHz bands, microwave ovens, infant monitors, radar, and the like. To the 802.11 WLAN devices, these other devices may be viewed as interferers. Some of these interferer devices transmit signals that hop to different center frequencies throughout the frequency band on a periodic or quasi-periodic basis. When transmissions of WLAN devices overlap in frequency and time with transmissions from interferer devices, the WLAN device may suffer partial, substantial or complete loss of signal, reduced signal quality or decreased throughput. Likewise, the interferer devices may suffer similar problems.
To reduce or eliminate interference with interferer devices, it is often desirable to ascertain where on the spectrum of available frequencies a device is operating. Typically, a spectrum analyzer is utilized to make this determination. A spectrum analyzer is essentially a receiver that is tuned or swept across a band of frequencies, and the amplitude of received signals is displayed on a display as a function of frequency. Conventional spectrum analyzers focus on features that enhance the accuracy of measurements, such as: sweep time, resolution bandwidth, and frequency range. These features often require specialized hardware. For instance, conventional spectrum analyzers typically contain dedicated hardware capable of quickly taking precise measurements. This specialized hardware is typically bulky and cost prohibitive for a small scale user, such as a small business, personal computer user or highly mobile technical support personnel.
Conventional spectrum analyzers also lack certain spectrum display and data manipulation features, creating additional work for a user desiring a particular spectrum display or spectrum data manipulation. For example, conventional spectrum analyzers typically graph amplitude versus frequency, requiring users to mentally map channels utilized by devices onto the frequency axis. Additionally, conventional spectrum analyzers do not provide the ability to save the measurement data for playback at a future time. Furthermore, while conventional spectrum analyzers allow an image to be saved, the image is generally only a representation of a single instant in time.
Consequently, it would be desirable to provide a system and method for portable analyzing and trouble shooting a frequency spectrum having enhanced graphical display and data manipulation features.