Abstract: A system may include a detection circuit and a controller. The detection circuit may detect a parameter of smart lights. The controller may transmit a lighting signal addressed to a portion of the smart lights. The lighting signal may cause particular channels of the portion of the smart lights to turn on. The controller may receive a parameter message from the detection circuit indicating a level of the parameter of the smart lights when the particular channels of the portion of the smart lights are on. The controller may compare the level of the parameter to a threshold value range. The controller, responsive to the level of the parameter being outside of the threshold value range, may transmit a message to a remote device. The message may indicate that the particular channels of the portion of the smart lights are not operating in accordance with a pre-determined profile.

Abstract: A method and transmitter and receiver for determining and transmitting or receiving a non-uniform QAM signal comprises selecting a signal to noise ratio for a channel and forward error corrector and then determining positions of constellation points that maximise a measure of channel capacity at the selected signal to noise ratio. The position of one constellation point and another constellation point within the constellation are constrained to be equal to one another prior to determining the positions of the constellation points. In doing so, a so called condensed QAM constellation arrangement may be derived having fewer than conventional number of constellation points for a given QAM scheme. The condensed QAM arrangement has improved performance at certain signal to noise ratios.