Abstract: An initiating key-agreement device (100) and a responding key-agreement device (200) are provided, configured to generate a symmetric key shared between them. The devices are configured for generating in electronic form a private random value (112, 212), obtaining in electronic form a public set of bivariate polynomials (122) and computing a univariate polynomial (124, 222) by summing the univariate polynomials obtained by substituting the private random value (112, 212) into the polynomials of the public set (122). The devices are configured to send their computed univariate polynomial to the other device, and to compute or reconstruct the shared symmetric key (214, 312) by substituting its generated private random value (112, 212) in the received univariate polynomial.

Abstract: The invention relates to a disaggregation apparatus for identifying an appliance in an electrical network (2) comprising multiple appliances (3, 4, 5). A voltage meter (7) measures a first change in a mains voltage (V) delivered to the appliances of the electrical network, while an operational state of an appliance is modified, and a second change in the mains voltage, while a switchable load is switched. An appliance determination unit (9) determines the appliance, of which the operational state has been changed, based on the measured first change in the mains voltage, the measured second change in the mains voltage and the resistance of the switchable load. Thus, an appliance can be determined without detecting switching flickers in very short time durations, i.e. high sampling rates and continuous monitoring are not necessarily required. This reduces the technical efforts of the disaggregation apparatus for performing the disaggregation function.

Abstract: The invention relates to an information encoder, and decoder, a signal and a method of encoding and decoding of information for a coded light system. The invention aims to provide amongst others a method for transmitting and receiving a message (msg1, . . . , msg6) in a system for visible light communication and wherein the message comprises a plurality of source symbols and wherein the method for transmitting comprises: generating a modulation signal by mapping the source symbols of the message onto channel symbols for modulating the output of the light source, wherein the message is partitioned into a plurality of packets (d1, . . . , d3) of consecutive channel symbols and wherein idle periods (i1, . . .

Abstract: A coded light signal is embedded into visible light emitted from the light source, to be received by a rolling-shutter camera which captures frames (16) by exposing a plurality of lines (18, 24) of each frame in sequence, the camera having an exposure time with each line being exposed for the exposure time. The coded light signal is formatted according to a format whereby the coded light signal comprises at least one message and the message is repeated multiple times with a timing such that, when samples of the coded light signal are obtained from a substantially smaller number of lines (24) than exposed by the camera in each frame and the message is longer than this number of lines, a different part of the message is seen by the camera in each of a plurality of different ones said frames.

Abstract: A Wiener filter for equalizing an effect of a first filter on an input signal which is subject to the first filter and to noise and/or interference, wherein: the first filter is dependent on at least one unknown quantity; and the Wiener filter is configured based on an averaged representation of the first filter averaged over the at least one unknown quantity, in place of a representation of the first filter being assumed to be known.

Abstract: A device comprising: an input for receiving a signal from a rolling-shutter camera which captures frames by exposing a lines of each frame in sequence, the signal comprising a coded light signal; and a signal processing module arranged to obtain a respective sample of the coded light signal from each of a number of said lines, being a substantially smaller number of the lines than exposed by the camera in each frame. The coded light signal comprises a message having a duration longer than this number of lines, and the message is repeated multiple times with a timing such that a different part of the message is seen by the camera in each of a plurality of different ones of said frames. The signal processing module is configured to time align the different parts of the message from the plurality of different frames, and reassemble the message from the time-aligned parts.

Abstract: A system (200) for configuring a network device (300) for sharing a key, the shared key being • bits long, the system comprising:—a key material obtainer (210) for—obtaining in electronic form a first private set of bivariate polynomials (252, {hacek over (z)}?(,)), and a second private set of reduction integers (254, f?), with each bivariate polynomial in the first set there is associated a reduction integer of the second set, and a public global reduction integer (256, . . .

Abstract: There is provided a light detection system which is capable of determining in light embedded codes by detecting light in a scene which is illuminated by an illumination system (110) comprising one or more light sources (111,112,113) each providing a light contribution (I111, I112, I113) comprising an embedded code (ID#1, ID#2, ID#3) emitted as a temporal sequence of modulations in a characteristics of the light emitted. The light detection system comprises light detection means (220), which are arranged for acquiring at least one image of the scene, where the image is acquired a plurality of temporal shifted line instances. Each line of the acquired image comprises an instance of the temporal sequence of modulations of the first embedded code. The light detection system further comprises means (230) for determining embedded codes from the spatial pattern of modulations.

Abstract: The present invention relates to a method of controlling a dimmable luminaire co-arranged with a light sensor at a first level of a room and illuminating a second level of the room, comprising: determining an output path parameter representing a relation between the amount of light emitted from the luminaire and a luminaire illumination value at the second level, which results from the emitted amount of light; and repeatedly: determining an external illumination value at the second level, which external illumination value represents illumination by other sources than the luminaire, by means of values of the presently emitted amount of light, the output path parameter, and light information originating from the light sensor; and controlling the dimming level of the luminaire on basis of the external illumination value in order to meet a predetermined illumination condition for the total illumination at the second level.

Abstract: A system (200) for configuring a network device (300) for key sharing is provided, and a first (300) and second network device configured to determine a shared key between them.

Abstract: Coded light has been proposed to enable advanced control of light sources and transmit information using light sources. Sequences of channel symbols to drive the light source are determined from sequences of source symbols such that no visible flicker is present in coded light emitted by the light sources. Each source symbol is mapped to a composite channel symbol comprising at least one first channel symbol which may be identical to the current source symbol and at least one second channel symbol which may be a function of the current source symbol and at least one future and/or past source symbol.

Abstract: The invention relates to a disaggregation apparatus (4) for being used in a multi-group electrical network (5), which comprises multiple electrical groups (1, 2, 3), each comprising one or more appliances (11, 12, 13, 21, 22, 23, 31, 32, 33). A determination unit (7) determines an electrical group (1, 2, 3) comprising an appliance, of which an operational state has been changed, based on first changes in mains voltages (V1, V2, V3) measured while the operational state change occurs, second and third changes in the mains voltages (V1, V2, V3) measured while switchable loads (1n, 2n, 3n) are switched, and the resistances (R1n, R2n, R3n) of the switchable loads (1n, 2n, 3n). Thus, a misdetection due to an operational state change of an appliance in another electrical group may be avoided and the accuracy of disaggregation may be improved in a multi-group electrical network (5).

Abstract: Electronic signature system comprising an electronic key generation device (100) for generating a digital signing-key for digitally signing digital data and a corresponding verification-key for digitally verifying said digitally signed data, an electronic signature generation device (200) for generating a digital signature for digital data using a digital signing-key obtained from an electronic key generation device, and an electronic signature verification device (300) for verifying a digital signature generated by an electronic signature generation device. The verifier has access to a commitment integer and corresponding polynomial derived from private keying material, enabling verification of signature polynomials derived the same private keying material.

Abstract: There is provided a light detection system which is capable of determining in light embedded codes by detecting light in a scene which is illuminated by an illumination system (110) comprising one or more light sources (111,112,113) each providing a light contribution (I111, I112, I113) comprising an embedded code (ID#1, ID#2, ID#3) emitted as a temporal sequence of modulations in a characteristics of the light emitted. The light detection system comprises light detection means (220), which are arranged for acquiring at least one image of the scene, where the image is acquired a plurality of temporal shifted line instances. Each line of the acquired image comprises an instance of the temporal sequence of modulations of the first embedded code. The light detection system further comprises means (230) for determining embedded codes from the spatial pattern of modulations.

Abstract: The invention provides a communication system (500), a lighting system, a method of transmitting information and a computer program product. The communication system according to the invention is configured for transmitting data via visible light. The communication system comprises a signal generator (530) for generating a light driving signal (200) being a frequency shift key modulated signal comprising a sequence of signal parts (215, 225), each signal part being modulated at a first or second frequency in accordance with the data, the signal parts modulated at the first frequency having first pulses in first periods (T0) and the signal parts modulated at the second frequency having second pulses in second periods (T1). Energy of the visible light corresponding to a pulse in a respective period has center of gravity in time.

Abstract: The invention relates to a method for automatic grouping of light sources within an illumination system. The method is performed starting from a first light source of the illumination system emitting a first light signal and a first sound signal. The method includes steps of using an intensity of the first light signal as received by a second light source and an intensity of the first sound signal as received by the second light source to determine a value of a grouping function (410, 420), and assigning the first light source and the second light source to the same group of light sources when the determined value of the grouping function satisfies one or more pre-determined conditions (430, 440, 450). In this manner, a determination could be made whether or not the first and second light sources should be assigned to the same group in a manner that yields improved results over the prior art solutions.

Abstract: The invention relates to a device (35) and a method for determining an individual power representation of operation states of a plurality (10) of loads, wherein such information on the individual power representation may furthermore be used for monitoring for malfunctions of a load (15) included in the plurality (10) of loads. In order to provide a cost effective approach to determining an individual power representation of operation states of a plurality (10) of loads, parameterizations of the individual power representations P(j, sj; t) with a finite set of parameters are chosen in order to find the best parameter fit to measurements on energy consumption.

Abstract: The invention relates to a power consumption monitoring apparatus (11) for monitoring the power consumed in a network (1) of electrical devices (3, 4, 5; 6, 7, 8). An electrical parameter measuring unit measures an overall electrical parameter of the network over time,a group signature providing unit provides group signatures, wherein each group signature is indicative of an electrical parameter of a certain group (9; 10) of electrical devices over time, and a disaggregation unit disaggregates the measured overall electrical parameter over time for determining the power consumption of the individual groups of electrical devices depending on the provided group signatures. This allows disaggregating the overall electrical parameter, without providing for each group an individual measuring unit, thereby reducing the required hardware and the time needed for installing and maintaining the power consumption monitoring apparatus.

Abstract: The invention relates to the field of IEEE 802.15.4 based networks, and in particular to methods and devices for transmitting and receiving messages in IEEE 802.15.4 based networks. The existing IEEE 802.15.4 standard is further improved and adapted to better fit the properties of a network of lighting devices. The improvements and adaptations of the existing IEEE 802.15.4 standard allow for more flexible addressing. Bits which are indicative of use of address fields and/or whether one or two frame control fields is/are present in the ordered data portions of the message to be transmitted are defined by the device transmitting the message in the IEEE 802.15.4 based network. Existing features of the existing IEEE 802.15.4 standard protocol are retained.

Abstract: There is provided a light detection system which is capable of determining in light embedded codes by detecting light in a scene which is illuminated by an illumination system (110) comprising one or more light sources (111,112,113) each providing a light contribution (I111, I112, I113) comprising an embedded code (ID#1, ID#2, ID#3) emitted as a temporal sequence of modulations in a characteristics of the light emitted. The light detection system comprises light detection means (220), which are arranged for acquiring at least one image of the scene, where the image is acquired a plurality of temporal shifted line instances. Each line of the acquired image comprises an instance of the temporal sequence of modulations of the first embedded code. The light detection system further comprises means (230) for determining embedded codes from the spatial pattern of modulations.