Core to our business is the planning, modeling and regulating of the radio broadcast signal. We use modern cellular LTE, broadcast and SFN software tools with the newest geospatial data-including high resolution building heights, vehicular traffic, and demographics. We create transmission site specific propagation coverage models correlated to drive test field measurements, and the full Fresnel complex integral sub-path analysis is used with diffraction (2D and 3D), ducting, and reflections. In combination with the high-resolution cartography, a standard deviation of less than 3 dB of the measured signal versus predicted is typical. These capabilities are critical in the design of SFN and Geo-Targeted system operation.
INTERFERENCE REDUCTION
Improving signal quality with the deployment of MaxxCasting cell sites not only increases the signal power level in areas where it was previously low, it also reduces interference from other channels. This is an increasingly common problem, as the FM band becomes more noisy due to translators, HD transmission, etc.
GeoBroadcast uses measurement and analysis tools such as the Octave Nomad™ both in the lab and in the field. In the lab, the Nomad helps gather measurements associated with the in-vehicle radio transmission test units; where we can simulate signal fading and the impact of vehicle speeds without actually driving. In the field, the Nomad is useful in detecting problems like second adjacent channel interference, which is a growing issue as more HD subchannels are being turned on. Automatically measuring adjacent channels, and providing a before and after analysis is a real advantage.
