Abstract: A communication protocol based on CSMA between a node, in particular an electronic label, and a network coordinator is disclosed. The node comprises:—a transceiver provided for communication with a network coordinator, wherein the transceiver handles a transmission channel based on CSMA;—a processing unit provided for processing data received via the transmission channel and displaying the data on a display unit. The electronic label is arranged to perform:—sending recurrently a data request packet;—going to a low power mode after sending the data request packet; and—waking-up for receiving a data response packet a predefined time interval after beginning sending the data request packet. The network coordinator is arranged to transmit the data response packet the predefined time interval after receiving the beginning of the data request packet.

Abstract: A communication protocol based on CSMA between a node, in particular an electronic label, and a network coordinator is disclosed. The node comprises: a transceiver provided for communication with a network coordinator, wherein the transceiver handles a transmission channel based on CSMA; a processing unit provided for processing data received via the transmission channel and displaying the data on a display unit. The electronic label is arranged to perform: sending recurrently a data request packet; going to a low power mode after sending the data request packet; and waking-up for receiving a data response packet a predefined time interval after beginning sending the data request packet. The network coordinator is arranged to transmit the data response packet the predefined time interval after receiving the beginning of the data request packet.

Abstract: The invention pertains to an optical coupler comprising at least one input waveguide, a coupling region, and a plurality of output waveguides. The coupling region comprises a plurality of coupled waveguides, which diverge with respect to each other in the propagation direction of electromagnetic radiation launched in the said input waveguide. In these couplers, both the amplitude distribution and a phase distribution can be accurately matched the output waveguides resulting in relatively low loss and cross-talk.

Abstract: The invention pertains to an optical coupler comprising at least one input waveguide, a coupling region, and a plurality of output waveguides. The coupling region comprises a plurality of coupled waveguides, which diverge with respect to each other in the propagation direction of electromagnetic radiation launched in the said input waveguide. In these couplers, both the amplitude distribution and a phase distribution can be accurately matched the output waveguides resulting in relatively low loss and cross-talk.