iHAT (Interactive Handover Analysis Tool) is an interactive software desktop tool used to determine the mutual interferometric coupling between two radio frequency (RF) transmitters broadcasting simultaneously in close proximity to each other. Roaming mobile units that need to transition communications link coverage from one RF access point (AP) to another may experience interferometric distortion due to competing AP transmissions. The interferometric distortion effects can be analyzed with this tool.

The software is written in Microsoft ® Visual Basic, and operates under Microsoft ® Excel 97 SR-1 (and other compatible versions). The software tool wills computer the interferometric distortion caused by two transmitters broadcasting simultaneously, and is capable of simulating interference due to amplitude, phase, and frequency differences in the two systems. This capability can be used to model potential interference between Amplitude Shift Keying (ASK), Phase Shift Keying (PSK), and Frequency Shift Keying (FSK) systems. Users can enter the location of the transmitters, and the parameters of their communications system in the table located in the Param Table worksheet.

The software tool also determines the spatial regions in the ISS environment that are dominant for each transmitter to aid in determining locations for the handover boundary from one AP to another. Once the input parameters are entered, the User executed the calculations by clicking the Calculate button located at the end of the link parameters table. Plots of the antenna gain for each AP transmitter is also determined and plotted. Line-of-sight (LOS) obstruction can also be plotted and incorporated into the plots.