Abstract: A method detects the surroundings of a node, in particular in the form of a sensor apparatus and/or actuator apparatus, of a communications network. The node is capable of unidirectional or bidirectional radio communication and has a radio module equipped with an antenna, a transmit path and/or receive path, and a power supply apparatus, which is preferably energy self-sufficient, in particular a battery. The surroundings are detected, preferably at repeated time intervals, on the basis of an estimate of the detuning of the antenna of the radio module.

Abstract: A multiplexer circuit (100) has at least two input channels (IN0, IN1) and an output channel (2). Each input channel (IN0, IN1) has a first transmission gate (FT0, FT1) and a second transmission gate (ST0, ST1). The transmission gate can be switched by a select signal (SELECT0, SELECT0; SELECT1, SELECT1) for connecting the input channel (IN0, IN1) to the output channel (2). At least one of the input channels (IN0, IN1) has a bypass circuit for preventing a current flowing through the first transmission gate (FT0, FT1) from reaching the other input channel.

Abstract: An address match determining device has an address filter memory (22) for storing a matrix or table having a plurality of elements each of which is a 1-bit address match determination data indicating whether or not a corresponding N-bit address code is available, and is distinguished by a pair of a first index composed of the m most significant or high-order m bits of the corresponding address code and a second index composed of the remaining lowest or low-order (N−m) bits of the corresponding address code. A received-address latch (21) extracts the high-order m bits and remaining low-order (N−m) bits from an address code latched thereinto.