The data compressor utilizes a plurality of character tables arranged in levels for storing strings of data characters, the character tables corresponding to respective characters of the alphabet. Display layouts are generated based on attributes associated with video streams received from the endpoints and display configuration information of the endpoints. The control circuit 32 operates the first and second drive circuits Q1, Q4; Q2, Q3 with an interval, and operates the discharging circuits Q5, G1, G2, Q6 during the interval. As a coin passes by the sensor, eddy currents are induced in the coin which result in phase and amplitude shifts in the low and high frequency components of the detector signal. Ratings may be stored according to the identity of the individual representing the first party, according to the identity of the business representing the first party, or according to the context of a call.