A status detection unit for a wireless communication system

Abstract

A status detection unit (200) for a wireless communication system (202) comprising a first communication module (204) and a second communication module (206), the first and second communication modules (204, 206) being configured to communicate using optical wireless communication through a barrier (208), wherein the status detection unit (200) is configured to determine an operational status of the wireless communication system (202).

Description

[0001] A STATUS DETECTION UNIT FOR A WIRELESS COMMUNICATION SYSTEM

[0002] The present disclosure relates to a status detection unit for a wireless communication system. In particular, the present disclosure relates to a status detection unit for a wireless communication system comprising two modules configured to communicate wirelessly through a barrier.

[0003] BACKGROUND

[0004] With the onset of satellite communication as well as terrestrial base stations that transmit data into homes and buildings wirelessly, there is now a need for reliable systems to send data signals into and out of buildings without the need for expensive retrofitting, e.g. drilling holes into walls for antennae.

[0005] Figure 1 is a schematic of a system 100 for wireless optical and / or radio frequency transmission through glass windows. The system 100 comprises an internal module 102 and an external module 104, with a glass window 106 being sandwiched between the modules 102, 104. The opposing internal and external modules 102, 104 are attached to respective glass surfaces.

[0006] The external module 104 acts as a transceiver and can send data from a base station to the internal opposing module which can send data into the room as well as send power to the external module through glass by induction. The external module 104 is coupled to an antenna 108 and the internal module 102 is coupled to a home network 110.

[0007] However, there are several different types of glass used in windows (e.g. float, tempered, low emission glass or tinted glass) and windows also come in a variety of designs, for example, with two or more glass barriers separated by various thicknesses of air for insulation. All these aspects have negative impacts on data transfer rates and power transfer between each module. SUMMARY

[0008] It is desirable to provide a device for improving wireless communication through barriers.

[0009] According to a first aspect of the disclosure there is provided a status detection unit for a wireless communication system comprising a first communication module and a second communication module, the first and second communication modules being configured to communicate through a barrier, wherein the status detection unit is configured to determine an operational status of the wireless communication system.

[0010] Optionally, the first and second communication modules are configured to be attached to opposing surfaces of the barrier.

[0011] Optionally, the first communication module comprises a first transmitter configured to send data to the second communication module and / or a first receiver configured to receive data from the second communication module, and the second communication module comprises a second transmitter configured to send data to the first communication module and / or a second receiver configured to receive data from the first communication module.

[0012] Optionally, the first communication module comprises a first optical front end (OFE) comprising the first transmitter and / or first receiver, and the second communication module comprises a second optical front end (OFE) comprising the second transmitter and / or second receiver.

[0013] Optionally, the first transmitter and / or the second transmitter each comprise one or more light emitters, and / or the first receiver and / or the second receiver each comprise one or more photodetectors. Optionally, the one or more light emitters comprises one or more of a light emitting diode (LED), an array or an arrangement of LEDs, a laser, or a light- emitting plasma.

[0014] Optionally, the one or more LEDs is one or more of an OLED or a micro LED.

[0015] Optionally the laser is a vertical-cavity surface-emitting laser (VCSEL).

[0016] Optionally, the one or more photodetectors comprises one or more of a photodiode, an array or an arrangement of photodiodes, a silicon PIN photodiode, a silicon photomultiplier (SiPM), a single photon avalanche diode (SPAD), a Graphene-CMOS high-resolution sensor, an avalanche photodiode (APD), a positive-intrinsic- negative (PIN) device, a phototransistor, a photoresistor, or a light activated silicon controlled rectifier.

[0017] Optionally, the first communication module comprises a first RF front end comprising the first transmitter and / or first receiver, and the second communication module comprises a second RF front end comprising the second transmitter and / or second receiver.

[0018] Optionally, the first communication module comprises a first power supply unit, and the second communication module comprises a second power supply unit.

[0019] Optionally, the first power supply unit is configured to wirelessly supply power to second power supply unit through the barrier.

[0020] Optionally, the first power supply unit is configured to wirelessly supply power to second power supply unit through the barrier using inductive energy transfer, capacitive energy transfer, radio frequency energy transfer or laser power energy transfer. Optionally, the first communication module comprises a first digital receiver and / or a first digital transmitter, and the second communication module comprises a second digital receiver and / or a second digital transmitter.

[0021] Optionally, the first digital receiver and / or the second digital receiver is one or more of an optical receiver, an electrical receiver or an optoelectrical receiver, and / or the first digital transmitter and / or the second digital transmitter is one or more of an optical transmitter, an electrical transmitter or an optoelectrical transmitter.

[0022] Optionally, the first communication module comprises a first optical component for the first transmitter and / or a second optical component for the first receiver, and / or the second communication module comprises a third optical component for the second transmitter and / or a fourth optical component for the second receiver.

[0023] Optionally, the first optical component comprises one or more diffusers and / or one or more lenses, and / or one or more lightpipes, and / or one or more waveguides, and / or one or more attenuators, and / or one or more filters, and / or one or more polarisers.

[0024] Optionally, the second optical component comprises one or more diffusers and / or one or more lenses, and / or one or more lightpipes, and / or one or more waveguides, and / or one or more attenuators, and / or one or more filters, and / or one or more polarisers.

[0025] Optionally, the third optical component comprises one or more diffusers and / or one or more lenses, and / or one or more lightpipes, and / or one or more waveguides, and / or one or more attenuators, and / or one or more filters, and / or one or more polarisers.

[0026] Optionally, the fourth optical component comprises one or more diffusers and / or one or more lenses, and / or one or more lightpipes, and / or one or more waveguides, and / or one or more attenuators, and / or one or more filters, and / or one or more polarisers.

[0027] Optionally, the first optical component comprises a first attenuator, and / or the second optical component comprises a second attenuator, and / or the third optical component comprises a third attenuator, and / or the fourth optical component comprises a fourth attenuator.

[0028] Optionally, the first and / or second and / or third and / or fourth attenuator comprises one or more of a liquid lens, a liquid crystal display (LCD), a polarising filter, or a neutral density (ND) filter.

[0029] Optionally, the first and / or second and / or third and / or fourth attenuators comprise an automatic gain control.

[0030] Optionally, the first communication module comprises a first digital data interface and the second communication module comprises a second digital data interface.

[0031] Optionally, the first digital data interface and the second digital data interface each comprise one or more of an ethernet interface, a USB interface or a PCle interface, an HDM1 interface, an InfiniBand interface, a Thunderbolt cable interface, a channels for end points interface, a CAN bus interface, an SP1 interface, an SD10 interface, a UART interface, a JESD204B interface, a PON interface and / or a secondary access point interface, or the first digital data interface and the second digital data interface each comprise at least one USB-C gigabit ethernet interface, or the first digital data interface comprises a 24V DC jack and has an input between 50W and 100W, and the second digital data interface has an input between 5W and 30W.

[0032] Optionally, the second digital interface is configured to be couplable to an electronic device.

[0033] Optionally, the electronic device comprises a modem. Optionally, the modem comprises a duplexer, a transmitter, a receiver, an oscillator, an intermediate frequency (IF) unit, a decode and forward unit, and an optical coupler.

[0034] Optionally, the decode and forward unit is a decode and forward baseband modem unit.

[0035] Optionally, the barrier is substantially transparent to the wavelengths of the electromagnetic radiation used for communication between the first and second communication modules.

[0036] Optionally, the barrier comprises one or more layers.

[0037] Optionally, the barrier comprises one or more layers of a transparent glass, translucent glass, a transparent plastic or a translucent plastic.

[0038] Optionally, the transparent plastic is acrylic or polycarbonate, and / or the translucent glass is one of float glass, low emission glass, laminated glass, obscured glass, insulated glass or tinted glass.

[0039] Optionally, the barrier is between 5mm and 50mm thick.

[0040] Optionally, the barrier is between 10mm and 40mm thick.

[0041] Optionally, the barrier is between 20mm and 30mm thick.

[0042] Optionally, the status detection unit is configured to adjust the first communication module and / or the second communication module based on the operational status.

[0043] Optionally, the status detection unit is configured to determine an operational status of the wireless communication system based on the rate of communication between the first communication module and the second communication module. Optionally, the status detection unit is configured to determine one or more properties of the barrier based on the determined operational status.

[0044] Optionally, the one or more properties comprises barrier composition, barrier thickness, number of barriers, distance between barriers, type of coating on the barrier, number of coating layers of each barrier, temperature, and intactness of the barrier.

[0045] Optionally, the status detection unit comprises a test signal transmitter configured to transmit a test signal and a test signal sensor configured to detect the test signal from the transmitter after it is reflected by the barrier, the operational status and therefore the one or more properties of the barrier being determined based on the test signal.

[0046] Optionally, the status detection unit is configured to perform a time of flight measurement using the test signal to determine the operational status.

[0047] Optionally, the test signal is one of an optical signal or an acoustic signal.

[0048] Optionally, the status determination unit is configured to determine the one or more properties of the barrier using software, algorithms, artificial intelligence with machine learning and / or pilot tones.

[0049] Optionally, the status detection unit is configured to adjust the first communication module and / or the second communication module based on the determined one or more properties of the barrier.

[0050] Optionally, the status detection unit is configured to determine an operational status of the wireless communication system based one or more of the rate of communication between the first communication module and the second communication module, the power exchange rate between the first power supply unit and the second power supply unit, and / or the temperature of one or both of the first communication module and the second communication module.

[0051] Optionally, the status detection unit is configured to determine one or more properties of the barrier based on the determined operational status.

[0052] Optionally, the one or more properties comprises barrier composition, barrier thickness, number of barriers, distance between barriers, type of coating on the barrier, number of coating layers of each barrier, temperature, and intactness of the barrier.

[0053] Optionally, the status detection unit comprises a test signal transmitter configured to transmit a test signal and a test signal sensor configured to detect the test signal from the transmitter after it is reflected by the barrier, the operational status and therefore the one or more properties of the barrier being determined based on the test signal.

[0054] Optionally, the status detection unit is configured to perform a time of flight measurement using the test signal to determine the operational status.

[0055] Optionally, the test signal is one of an optical signal or an acoustic signal.

[0056] Optionally, the test signal transmitter is a white light LED.

[0057] Optionally, the status determination unit is configured to determine the one or more properties of the barrier using software, algorithms, artificial intelligence with machine learning and / or pilot tones.

[0058] Optionally, the status detection unit is configured to adjust the first communication module and / or the second communication module based on the determined one or more properties of the barrier. Optionally, the status detection unit is configured to receive data relating to the efficiency and / or input-output voltage of the first power supply unit and the second power supply unit, and calculate the gain and / or attenuation of the first and second communication modules usingthe received data, and adjust the first communication module and / or the second communication module based on the calculated gain and / or attenuation.

[0059] Optionally, the status detection unit comprises a first status detection module coupled to the first communication module and a second status detection module coupled to the second communication module.

[0060] Optionally, the first status detection module and the second status detection module are configured to communicate through the barrier.

[0061] Optionally, the first status detection module is configured to communicate the operational status to the second status detection module through the barrier and / or the second status detection module is configured to communicate the operational status to the first status detection module through the barrier.

[0062] Optionally, the first status detection module and the second status detection module are configured to communicate usingthe Transmission Control Protocol.

[0063] Optionally, the first status detection module and the second states detection module are configured to communication using optical wireless communication through the barrier.

[0064] Optionally, the first status detection module and the second status detection module are configured to communicate reference clock data relating to their respective communication modules, and to synchronise their respective communication modules based on the reference clock data. Optionally, the first communication module comprises a first digital receiver and / or a first digital transmitter, and the second communication module comprises a second digital receiver and / or a second digital transmitter.

[0065] Optionally, the first digital receiver and / or the second digital receiver is one or more of an optical receiver, an electrical receiver or an optoelectrical receiver, and / or the first digital transmitter and / or the second digital transmitter is one or more of an optical transmitter, an electrical transmitter or an optoelectrical transmitter.

[0066] Optionally, the first communication module comprises a first optical component for the first transmitter and / or a second optical component for the first receiver, and / or the second communication module comprises a third optical component for the second transmitter and / or a fourth optical component for the second receiver.

[0067] Optionally, the first optical component comprises one or more diffusers and / or one or more lenses, and / or one or more lightpipes, and / or one or more waveguides, and / or one or more attenuators, and / or one or more filters, and / or one or more polarisers.

[0068] Optionally, the second optical component comprises one or more diffusers and / or one or more lenses, and / or one or more lightpipes, and / or one or more waveguides, and / or one or more attenuators, and / or one or more filters, and / or one or more polarisers.

[0069] Optionally, the third optical component comprises one or more diffusers and / or one or more lenses, and / or one or more lightpipes, and / or one or more waveguides, and / or one or more attenuators, and / or one or more filters, and / or one or more polarisers.

[0070] Optionally, the fourth optical component comprises one or more diffusers and / or one or more lenses, and / or one or more lightpipes, and / or one or more waveguides, and / or one or more attenuators, and / or one or more filters, and / or one or more polarisers.

[0071] Optionally, the first optical component comprises a first attenuator, and / or the second optical component comprises a second attenuator, and / or the third optical component comprises a third attenuator, and / or the fourth optical component comprises a fourth attenuator.

[0072] Optionally, the first and / or second and / or third and / or fourth attenuator comprises one or more of a liquid lens, a liquid crystal display (LCD), a polarising filter, or a neutral density (ND) filter.

[0073] Optionally, the first and / or second and / or third and / or fourth attenuators comprise an automatic gain control.

[0074] Optionally, the first communication module comprises a first digital data interface and the second communication module comprises a second digital data interface.

[0075] Optionally, the first digital data interface and the second digital data interface each comprise one or more of an ethernet interface, a USB interface or a PCle interface, an HDM1 interface, an InfiniBand interface, a Thunderbolt cable interface, a channels for end points interface, a CAN bus interface, an SP1 interface, an SD10 interface, a UART interface, a JESD204B interface, a PON interface and / or a secondary access point interface, or the first digital data interface and the second digital data interface each comprise at least one USB-C gigabit ethernet interface, or the first digital data interface comprises a 24V DC jack and has an input between 50W and 100W, and the second digital data interface has an input between 5W and 30W.

[0076] Optionally, the second digital interface is configured to be couplable to an electronic device.

[0077] Optically the electronic device is a modem. Optionally, the modem comprises a duplexer, a transmitter, a receiver, an oscillator, an intermediate frequency (IF) unit, a decode and forward unit, and an optical coupler.

[0078] Optionally, the decode and forward unit is a decode and forward baseband modem unit.

[0079] Optionally, the barrier is substantially transparent to the wavelengths of the electromagnetic radiation used for communication between the first and second communication modules.

[0080] Optionally, the barrier comprises one or more layers.

[0081] Optionally, the barrier comprises one or more layers of a transparent glass, translucent glass, a transparent plastic or a translucent plastic.

[0082] Optionally, the transparent plastic is acrylic or polycarbonate, and / or the translucent glass is one of float glass, low emission glass, laminated glass, obscured glass, insulated glass or tinted glass.

[0083] Optionally, the barrier is between 5mm and 50mm thick.

[0084] Optionally, the barrier is between 10mm and 40mm thick.

[0085] Optionally, the barrier is between 20mm and 30mm thick.

[0086] Optionally, the first OFE comprises a first plurality of transmitters comprising the first transmitter and / or a first plurality of receivers comprising the first receiver, and / or the second OFE comprises a second plurality of transmitters comprising the second transmitter and / or a second plurality of receivers comprising the second receiver. Optionally, each of the first plurality of transmitters are configured to transmit at the same wavelength.

[0087] Optionally, each of the first plurality of transmitters are configured to transmit at different wavelengths.

[0088] Optionally, each of the first plurality of receivers are configured to receive at the same wavelength.

[0089] Optionally, each of the first plurality of receivers are configured to receive at different wavelengths.

[0090] Optionally, each of the second plurality of transmitters are configured to transmit at the same wavelength.

[0091] Optionally, each of the second plurality of transmitters are configured to transmit at different wavelengths.

[0092] Optionally, each of the second plurality of receivers are configured to receive at the same wavelength.

[0093] Optionally, each of the second plurality of receivers are configured to receive at different wavelengths.

[0094] Optionally, the first communication module comprises one or more first additional optical front ends (OFE) each comprising a first additional transmitter and / or a first additional receiver, and the second communication module comprises one or more second additional optical front ends (OFE) each comprising a second additional transmitter and / or a second additional receiver.

[0095] Optionally, the first transmitter and each of the first additional transmitters are configured to transmit at the same wavelength. Optionally, the first transmitter and each of the first additional transmitters are configured to transmit at different wavelengths.

[0096] Optionally, the first receiver and each of the first additional receivers are configured to receive at the same wavelength.

[0097] Optionally, the first receiver and each of the first additional receivers are configured to receive at different wavelengths.

[0098] Optionally, the second transmitter and each of the second additional transmitters are configured to transmit at the same wavelength.

[0099] Optionally, the second transmitter and each of the second additional transmitters are configured to transmit at different wavelengths.

[0100] Optionally, the second receiver and each of the second additional receivers are configured to receive at the same wavelength.

[0101] Optionally, the second receiver and each of the second additional receivers are configured to receive at different wavelengths.

[0102] The first and second communication modules may be configured to communicate through the barrier using an optical wireless communication channel, wherein the first and second modules comprise further wireless communication and / or other circuitry for establishing a further wireless link between the first and second module. The determined operational status of the system may be dependent on the further wireless link and / or communicated between the first and second modules using the further wireless link. The system may be configured to perform an initialization and / or calibration process for the OWC channel using the further wireless link. The system may be configured to perform a calibration process for the OWC channel in response to establishing the further wireless link. The system may be configured to send information about the OWC channel over the further wireless link. The system may be configured to determine one or more properties of the barrier based on the calibrated operational parameters.

[0103] The further wireless link may comprise at least one of: a wireless power link, Bluetooth or other RF communication, WiFi, near field communication, magnetic induction, further optical channel, acoustic signals.

[0104] The first and second communication modules may be configured to communicate using an OWC protocol and wherein communication over the further wireless link comprises communication using a different wireless protocol.

[0105] The first and / or second modules maybe further configured to perform a calibration procedure, wherein the calibration procedure comprises determining the operational status of the system and / or determining one or more operating parameters for the first and / or second module based on the operational status of the system and / or determining one or more characteristics of the OWC channel.

[0106] The first and / or second modules may be configured to perform a calibration procedure comprising: transmitting an optical signal from one of the first and second communication module to the other of the first and second module using the OWC communication channel, wherein the transmitted optical signal is dependent on one or more operational parameters and measuring or sensing a property of the received optical signal and / or a signal derived from the received optical signal at the other of the first and second modules; selecting and / or adjusting the one or more operational parameters based on the measured or sensed property.

[0107] The operational parameters may comprise one or more operational parameters for the OWC communication circuitry and / or an OWC transmitter and / or associated transmitter circuitry and / or optical front end of the modules and / or OWC receiver and / or associated receiver circuity. The one or more operational parameters may comprise one or more parameters associated with values of AC and DC values for an optical signal between the first and second modules. The one or more operational parameters may comprise an attenuation parameter or other parameter of a signal conditioning circuit. The one or more operational parameters may comprise one or more operational parameters for the first and / or second modules on which the AC and DC values or other measurable property of an optical signal are dependent. The one or more operational parameters may comprise an attenuation parameter or other parameter of a signal conditioning circuit. The one or more operational parameters may comprise a control parameter for an optical component of the transmitter and / or receiver.

[0108] The module may comprise a transmitter configured to transmit optical signals, optionally based on a driving signal, wherein the optical signals, optionally the driving signal comprises a first substantially constant portion and a second, time varying portion, wherein the operational parameters comprise at least one property of the first and / or second portions of the optical signal and / or driving signal.

[0109] The module may comprise signal conditioning circuitry, optionally, for conditioning a driving signal and delivering the conditioned driving signal to the transmitter, wherein the operational parameter comprises at least one parameter of the signal conditioning circuitry.

[0110] The measured or sensed property of the received optical signal and / or a signal derived from the optical signal may be representative of at least one characteristic of the OWC channel, optionally, a speed, data rate or signal quality.

[0111] The measured and / or sensed property may comprise at least one of: a property of a decoded or demodulated signal, optionally a baseband signal, optionally a data rate of the optical wireless communication channel, optionally an up or downlink of the channel. The sensed and / or measured property may comprises a temperature.

[0112] The first and / or second module may be configured to transfer power wirelessly wherein the calibration process is performed in response to the power or energy transfer between modules and / or wherein information associated with the OWC channel is communicated over a wireless power transfer communication link.

[0113] One of the first and second modules may be configured to detect the start of wireless power transfer and, in response to the start of wireless power transfer, start a calibration process.

[0114] The one or more measured or sensed properties may comprise at least one of: a] a determined temperature; b] a property of the received optical signal; c] a property of an electronic signal derived from the optical signal,

[0115] The first and / or second modules may be configured to: identify from a plurality of pre-determined points in an operational parameter space, a first point that provides the best OWC channel performance; determine a further point in parameter space based on the first point that provides an improved OWC channel performance.

[0116] The plurality of pre-determined points may be provided along one or more curves, lines or surfaces formed in the parameter space.

[0117] The pre-determined points may be separated by a distance in the parameter space and wherein determining the further point comprises adjusting the point or otherwise exploring the parameter space in a region about the first point characterised by a dimension smaller than said distance and / or adjusting the first point. The first and / or second module may be configured to calibrate the OWC communication channel and / or an operational parameter of the system using optical test signals carrying substantially no data and / or substantially no network data and / or generated using an electronic tone signal.

[0118] The first and / or second module may comprise an electronic test signal generator for generating an electronic test signal for the optical front end and a data signal generator, optionally a baseband or other processor, configured to generate a data signal for the optical front end, wherein the first and / or second module is configured to switch between a first configuration in which the electronic test signal generator is coupled to the transmitter and associated circuitry and a second configuration in which the data signal circuitry is connected to the transmitter and associated circuitry

[0119] The at least one operational parameter may comprise a property of a bias current provided to the transmitter, a property of a signal conditioning circuitry at the transmitter and / or receiver, a property of a drive signal, a property of an optical component at the receiver and / or transmitter, a property of a photodetector.

[0120] The first and / or second module may comprise signal conditioning circuitry comprising at least one controllable component that changes a characteristic of the OWC channel, optionally wherein the controllable component comprises at least one or more of a filter, attenuator, amplifier, balun, logarithmic amplifier, splitter, switch, transmitter bias adjustment circuit.

[0121] The first and / or second module may comprise at least one measurement device or sensor for measuring or sensing the at least one property of the OWC channel, optionally, wherein the measurement or sensing device comprises an ADC and sampling circuitry, a peak detector or, for example, an RMS detector.

[0122] The determined and / or sensed property may comprise at least one of: a peak, an amplitude, an amplitude or other property of a main frequency component of the received signal, optionally an amplitude or other property of one or more other frequency components of the received signal, a property of a sample of the received waveform, optionally a property of a digital representation of at least part of the waveform

[0123] The first and / or second module may comprise a temperature compensation circuitry configured to adjust the one or more operational parameters based on a detected temperature, optionally a temperature of the first and / or second module and / or an ambient temperature.

[0124] According to a second aspect of the disclosure there is provided a wireless communication system comprising the status detection unit of the first aspect, the first communication module of the first aspect, and the second communication module of the first aspect.

[0125] It will be appreciated that the wireless communication system of the second aspect may include features set out in the first aspect and can incorporate other features as described herein.

[0126] According to a third aspect of the disclosure there is provided a method of detecting the status of a wireless communication system using the status detection unit of the first aspect, the method comprising determining the operational status of the wireless communication system using the status detection unit.

[0127] It will be appreciated that the wireless communication system of the third aspect may include providing and / or using features set out in the first aspect and can incorporate other features as described herein.

[0128] According to a further aspect of the disclosure there is provided a method of calibrating a wireless communication system and / or an OWC channel of the system and / or one or more operational parameters of an OWC system, the method comprising: determining the operational status of the system and / or determining one or more operating parameters for the first and / or second module based on the operational status of the system and / or determining one or more characteristics of the OWC channel.

[0129] The system may be in accordance with the second aspect or as described herein.

[0130] The method may comprise transmitting an optical signal from one of the first and second communication module to the other of the first and second module using the OWC communication channel, wherein the transmitted optical signal is dependent on one or more operational parameters and measuring or sensing a property of the received optical signal and / or a signal derived from the received optical signal at the other of the first and second modules; selecting and / or adjusting the one or more operational parameters based on the measured or sensed property.

[0131] The method may comprise: identifying, from a plurality of pre-determined points in an operational parameter space, a first point that provides the best OWC channel performance; determining a further point in parameter space based on the first point that provides an improved OWC channel performance. Best OWC channel performance may be determined based on a measured and / or sensed property of the OWC channel.

[0132] The first and / or second module may be configured to transfer power wirelessly wherein the calibration process is performed in response to the power or energy transfer between modules and / or wherein information associated with the OWC channel is communicated over a wireless power transfer communication link. One of the first and second modules may be configured to detect the start of wireless power transfer and, in response to the start of wireless power transfer, start a calibration process. The calibration may be performed using the further wireless link. The calibration may be performed in response to establishing a further wireless link between the modules. It will be appreciated that features of one aspect may be provided as features another aspect. For example, system features may be provided as method features and vice versa.

[0133] BRIEF DESCRIPTION OF THE DRAWINGS

[0134] The disclosure is described in further detail below by way of example and with reference to the accompanying drawings in which:

[0135] Figure 1 is a schematic of a system for wireless optical and / or radio frequency transmission through glass windows;

[0136] Figure 2(a) is a schematic of a status detection unit for a wireless communication system in accordance with a first embodiment of the present disclosure, Figure 2(b) is a schematic of a specific embodiment of the wireless communication system of Figure 2(a) in accordance with a second embodiment of the present disclosure, Figure 2(c) is a schematic of a further specific embodiment of the wireless communication system of Figure 2(a) in accordance with a third embodiment of the present disclosure, Figure 2(d) is a schematic of a further specific embodiment of the wireless communication system of Figure 2(a) in accordance with a fourth embodiment of the present disclosure, Figure 2(e) is a schematic of a further specific embodiment of the wireless communication system of Figure 2(a) in accordance with a fifth embodiment of the present disclosure;

[0137] Figure 3(a) is a schematic of a further specific embodiment of the status detection unit and the wireless communication system of Figure 2(a) in accordance with a sixth embodiment of the present disclosure, Figure 3(b) is a schematic of a further specific embodiment of the status detection unit and the wireless communication system of Figure 2(a) in accordance with a seventh embodiment of the present disclosure, Figure 3(c) is a schematic of a further specific embodiment of the status detection unit and the wireless communication system of Figure 2(a) in accordance with an eighth embodiment of the present disclosure, Figure 3(d) is a schematic of a further specific embodiment of the status detection unit and the wireless communication system of Figure 2(a) in accordance with a ninth embodiment of the present disclosure, Figure 3(e) is a schematic of a further specific embodiment of the status detection unit and the wireless communication system of Figure 2(a) in accordance with a tenth embodiment of the present disclosure, Figure 3(f) is a schematic of a further specific embodiment of the status detection unit and the wireless communication system of Figure 2(a) in accordance with an eleventh embodiment of the present disclosure;

[0138] Figure 4(a) is a schematic of a further specific embodiment of the status detection unit and the wireless communication system of Figure 2(a) in accordance with an eleventh embodiment of the present disclosure, Figure 4(b) is a schematic of a further specific embodiment of the status detection unit and the wireless communication system of Figure 2(d) in accordance with an twelfth embodiment of the present disclosure; and

[0139] Figure 5(a) is a schematic of the status detection unit and a wireless communication system in accordance with a thirteenth embodiment of the present disclosure, Figure 5(b) is a schematic of the status detection unit and a wireless communication system in accordance with a fourteenth embodiment of the present disclosure.

[0140] Figure 6 depicts a wireless communication system in accordance with a further embodiment;

[0141] Figure 7 depicts a calibration process in accordance with an embodiment;

[0142] Figure 8 depicts part of a calibration process in accordance with an embodiment;

[0143] Figure 9 depicts a wireless communication system in accordance with a further embodiment;

[0144] Figure 10 depicts a wireless communication system in accordance with a further embodiment;

[0145] Figure 11 depicts a wireless communication system in accordance with a further embodiment;

[0146] Figure 12 depicts a calibration process in accordance with a further embodiment; Figure 13 depicts a wireless communication system in accordance with a further embodiment;

[0147] Figures 14 depicts a waveform of an optical signal;

[0148] Figure 15(a) to (e) depict a parameter space for different barrier types;

[0149] Figure 16(a) to (c) depicts plots of a parameter space for a calibration process, in accordance with an embodiment.

[0150] DETAILED DESCRIPTION

[0151] Figure 2(a) is a schematic of a status detection unit 200 for a wireless communication system 202 in accordance with a first embodiment of the present disclosure. The wireless communication system 202 comprises a communication module 204 and a communication module 206. The communication modules 204, 206 are configured to communicate wirelessly with each other through a barrier 208. During operation of the wireless communication system 202, the status detection unit 200 determines an operational status of the communication system 202.

[0152] The operational status relates to one or more characteristics of the communication system 202 during its operation, and relating to its operation. By way of example, the rate of data transfer through the barrier 208 can provide an indication of the operational status of the communication system 202. A lower than expected data rate can be indicative of the communication system 202 underperforming. In such a case, the operational status may be represented by the data rate itself. In a further embodiment, the operational status may, for example, be represented by a numerical rating, with the rating being dependent on the rate of data transfer. The operational status may depend on several factors. The operational status may relate to one or both of the communication modules 204, 206. In use, the modules 204, 206 may be attached to opposing surfaces of the barrier 208. In further embodiments, one or both of the modules 204, 206 may be in close proximity to the respective barrier 208 surfaces, without being attached.

[0153] The modules 204, 206 may be coupled to their respective surfaces magnetically, or using an adhesive. The modules 204, 206 may each comprise a seal (not shown) to exclude one or more of gas, particles, dust, oil or moisture from entering the interface space between the module 204, 206 and the barrier 208 surface. The seal may, for example, be a hermetic seal.

[0154] Each of the modules 204, 206 may comprise a coupling device (not shown) to align the modules 204, 206 for their attachment to the surface of the barrier 208. The coupling device can enable an unskilled person to manually assemble the system 202 either side of the barrier 208 and to provide proper alignment of the modules 204, 206 during assembly of the system 202.

[0155] The coupling device may comprise known visual tools such as optical spotting scopes with the aid of electrical metering of received signal strength indication (RSSI) signal to algin the modules, or an infrared emitter and infrared receiver that cooperate in known ways to indicate that alignment of the modules 204, 206 has been achieved.

[0156] In a further embodiment, alignment may be manually achieved by a spacer block and window coordinates on both sides.

[0157] The communication module 204 may be attached on the interior side of the barrier 208. For example, within an enclosed space such as a building, multistorey building, private dwelling, home, apartment, prefabricated house or mobile home. The communication module 206 may be attached on the exterior side of the barrier, being outside of the enclosed space. The modules 204, 206 may be applied to the either surface of the barrier 208 using an Unmanned Aerial Vehicle (UAV) or drone. The drone may, for example, be single use after attachment to the barrier surface.

[0158] The drones may comprise suitable components to enable alignment of the modules 204, 206 and also to couple the modules 204, 206 to their respective surfaces, for example by adhering to the surface using suction pads, magnets or adhesive. The external drone could detach if a storm is forecast or if the user no longer requires the system 202.

[0159] The use of a UAV or drone can mitigate mounting alignment issues and can avoid parallax error. The attachment system may be a spring-loaded system, that after a good alignment indication is received by the UAV or drone, actuates a control to lock the module into place.

[0160] The device may be assembled during the assembly of a framed window before installation in a house, either in a new building or as a replacement window, as is frequently done during house insulation upgrades.

[0161] One or both of the modules 204, 206 may comprise one or more sensors (not shown). The one or more sensors may detect movement nearby and may use algorithms to predict interference or removal of a module.

[0162] The system 202 may comprise a security alarm (not shown) to alert users to a fault or interference by a third party, as detected by a sensor. This may be particularly relevant for a module that is placed outdoors.

[0163] • The system 202 may also comprise sensors to monitor one or more of the external and / or internal module:

[0164] • temperature

[0165] • alignment of both modules

[0166] • functional and operational information energy supply device part authentication

[0167] The module placed indoors (for example the module 204) may comprise status indicators (not shown), such as several LEDs for status. Another further LED may transmit data to the outside module (for example, the module 206) and may use a light pipe to direct light from the LED to the outside module. The data may relate to clock signals, and therefore may be used for clock synchronization of the modules 204, 206.

[0168] The barrier 208 may be substantially transparent to the wavelengths of the electromagnetic radiation used for communication between the communication modules 204, 206. The barrier 208 may comprise one or more layers. The barrier 208 may comprise one or more layers of a transparent glass, translucent glass, translucent plastic or a transparent plastic. For example, the transparent plastic may be acrylic or polycarbonate, for example, the translucent glass may be float glass, low emission glass, laminated glass, obscured glass, insulated glass or tinted glass.

[0169] The barrier 208 may be between 5mm and 50mm thick, for example between 10mm and 40mm thick, for example, between 20mm and 30mm thick.

[0170] The modules 204, 206 may comprise FPGA to ASIC transition.

[0171] Figure 2(b) is a schematic of a specific embodiment of the wireless communication system 202 of Figure 2(a) in accordance with a second embodiment of the present disclosure. In the present embodiment, the communication module 204 comprises a transmitter 210 configured to transmit data to the communication module 206, and a receiver 212 configured to receive data from the communication module 206. The communication module 206 comprises a transmitter 214 configured to transmit data to the communication module 204, and a receiver 216 configured to receive data from the communication module 204. The transmitter 210 is configured to transmit data wirelessly to the receiver 212, and the transmitter 214 is configured to transmit data wirelessly to the receiver 216. The end to end data rate between the modules 204, 206 may be between 500 Mbps and 10 Gbps.

[0172] In the present embodiment, each of the communication modules 204, 206 comprises one of the transmitters 210, 214 and one of the receivers 212, 216. The transmitter 210 and the receiver 212 may be collectively referred to as a transceiver. Similarly the transmitter 214 and the receiver may be collectively referred to as a transceiver. It will be appreciated that in further embodiments, the communication between the modules 204, 206 may be one way, such that one of the modules 204, 206 may comprise a transmitter with no receiver, with the other of the modules 204, 206 comprising a receiver and no transmitter.

[0173] Embodiments described herein primarily relate to modules 204, 206 using bidirectional communication. It will be appreciated that in further embodiments of the present disclosure, any of the embodiments described herein using bidirectional communication may be adapted to provide one way communication in accordance with the understanding of the skilled person.

[0174] In a specific embodiment, each of the communication modules 204, 206 may comprise an optical front end (OFE), with their respective transmitters and receivers being includes as part of the OFE. In the OFE, the transmitters 210, 214 and receivers 212, 216 are configured to transmit and receive and optical wavelengths, respectively. The optical wavelengths may include visible and / or infrared (for example near infrared) and / or ultraviolet wavelengths. Such systems may be referred to as optical wireless communication (OWC) systems.

[0175] Each of the transmitters 210, 214 may comprise one or more light emitters. For example, the one or more light emitters may comprise one or more of a light emitting diode (LED), an array or an arrangement of LEDs, a laser, or a light- emitting plasma. The one or more LEDs may, for example, be one or more of an OLED or a micro LED. The laser may be a vertical-cavity surface-emitting laser (VCSEL). Each of the receivers 212, 216 may comprise one or more photodetectors. For example, the one or more photodetectors may comprise one or more of a photodiode, an array or an arrangement of photodiodes, a silicon PIN diode, a silicon photomultiplier (SiPM), a single photon avalanche diode (SPAD), a Graphene-CMOS high-resolution sensor, an avalanche photodiode (APD), a positive-intrinsic- negative (PIN) device, a phototransistor, a photoresistor, or a light activated silicon controlled rectifier. The OFE may comprise a light access module.

[0176] In a further embodiment, each of the communication modules 204, 206 may comprise an RF front end, with their respective transmitters and receivers being includes as part of the RF front end. In the RF front end, the transmitters 210, 214 and receivers 212, 216 are configured to transmit and receive and radio frequency (RF) wavelengths, respectively.

[0177] Figure 2(c) is a schematic of a further specific embodiment of the wireless communication system 202 of Figure 2(a) in accordance with a third embodiment of the present disclosure. With reference to the embodiment presented in Figure 2(b), the communication module 204 further comprises a power supply unit 218 and the communication module 206 further comprises a power supply unit 220.

[0178] The power supply units 218, 220 are arranged to enable power to be supplied to their respective modules 204, 206. For example, one or both of the power supply units 218, 220 may comprise a battery holder for holding a battery to power its module 204, 206. In a further embodiment, one or both of the power supply units 218, 220 may comprise a connector for coupling to a mains power supply or other power source.

[0179] In a specific embodiment, where the module 204 is within an enclosed space, such as a house, it may be powered by the power supply unit 218 being coupled to a mains power supply, which is available within the house. The module 206, being outside the house, may be powered by the power supply unit 220 holding a battery, with the mains supply not being readily available outside. In a specific embodiment, the power supply unit 218 may be configured to wirelessly supply power to the power supply unit 220. This will be of particular benefit for the above example where the module 204 is placed within a property with access to a mains power supply, which is not easily accessibly for the exterior module 206.

[0180] The power may, for example, be supplied through the barrier 208 using inductive energy transfer, capacitive energy transfer, radio frequency energy transfer or laser power energy transfer.

[0181] The status detection unit 200 may be implemented within one or both of the power supply units 218, 220.

[0182] One or both of the power supply units 218, 220 may monitor their received voltages and if necessary rectify the voltage on power channel.

[0183] Figure 2(d) is a schematic of a further specific embodiment of the wireless communication system 202 of Figure 2(a) in accordance with a fourth embodiment of the present disclosure. With reference to the embodiment presented in Figure 2(c), the communication module 204 further comprises a digital transceiver 222, and the communication module 206 comprises a digital transceiver 224.

[0184] It will be appreciated that each of the digital transceivers 222, 224 comprises a digital transmitter and a digital receiver. As discussed previously, for embodiments having single direction communication, there may be provided only one of the digital transmitter or the digital receiver for one of the modules 204, 206, and the other of the digital transmitter or the digital receiver for the other of the modules 204, 206 in accordance with the understanding of the skilled person.

[0185] The digital transceivers 222, 224 are each configured to receive and transmit digital signals received from their respective transmitters and receivers. For example, the digital transceiver 222 may receive a digital signal, convert the digital signal to an analog signal that is suitable for transmission, and then provide the analog signal to the transmitter 210 for wireless transmission. The digital transceiver 222 may receive an analog signal, as provided by the receiver 212, convert the analog signal to a digital signal, and then output the digital signal. The digital transceiver 224 will function similarly, as will be clear to the skilled person.

[0186] Each of the digital transceivers 222, 224 may be one or more of an optical transceiver, an electrical transceiver or an optoelectrical transceiver.

[0187] One or more of the transmitters 210, 214 and / or the receivers 212, 216 may have optical components. The optical components may comprise one or more of a diffuser, a lens, a lightpipe, a waveguide, an attenuator, a filter, and / or a polariser. Polarisers are particularly useful with multiple OFEs / transmitters to provide separation between signals.

[0188] The communication modules 204, 206 may comprise attenuators 226, 228, 230, 232 that are configured to attenuate signals. The attenuation by the attenuators may be used to prevent saturation of the optical, electrical or optoelectrical signals.

[0189] Each of the attenuators 226, 228, 230, 232 may comprise one or more a liquid lens, a liquid crystal display (LCD), or a filter such as a polarising filter or a neutral density (ND) filter. Each of the attenuators 226, 228, 230, 232 may comprise automatic gain control that automatically adjusts the attenuation to acquire the desired gain.

[0190] Each of the filters may differ from each other if the transmitters / receivers operate on different wavelengths.

[0191] The communication module 204 comprises a digital data interface 234 and the communication module 26 comprises a digital data interface 236. In a specific embodiment, each of the digital data interfaces 234, 236 may comprise one or more of an ethernet interface, a universal serial bus (USB) interface, a peripheral component interconnect (PCIe) interface, an HDMI interface, an InfiniBand interface, a Thunderbolt cable interface (for example Thunderbolt 3), a channels for end points interface, a CAN bus interface, an SPI interface, an SDIO interface, a UART interface, a JESD204B interface, a PON interface, and / or a secondary access point interface. The ethernet interface may be, for example, a 40GB ethernet interface. In a further embodiment, each of the digital data interfaces 234, 236 may comprise a USB-C gigabit ethernet interface. In a further embodiment the digital data interface 234 comprises a 24V DC jack and has an input between 50W and 100W, and the digital interface 236 comprises an input between 5W and 30W, preferably 20W.

[0192] The digital interface 236 may be configured to be couplable to an electronic device such as a modem 238. The modem 238 may be an external modem. The modem 238 is arranged to convert the digital data into an appropriate format for transmission, for example via an RF antenna. The modem 238 may be arranged to be battery powered.

[0193] The modem 238 may comprise a duplexer, a transmitter, a receiver, an oscillator, an intermediate frequency (IF) unit, a decode and forward unit, and an optical coupler. The decode and forward unit may be a decode and forward baseband modem unit.

[0194] The decode and forward unit amplifies signals in addition to signal forwarding thereby obviating the need to decode received signals at point of reception (antenna), providing optimal signal reception and transmission which in turn reduces the error rate of received and transmitted signals.

[0195] The interface 234 may be couplable to an electronic device 240, such as a network, such as a home network. The wireless communication system 202 of Figure 2(d) can permit communication in and out of an enclosed space through the barrier 208.

[0196] Figure 2(e) is a schematic of a further specific embodiment of the wireless communication system 202 of Figure 2(a) in accordance with a fifth embodiment of the present disclosure. It will be appreciated that the additional features of the present embodiment may be applied to any of the other embodiments described herein in accordance with the understanding of the skilled person.

[0197] In the present embodiment, the status detection unit 200 is configured to adjust the one or both of the communication module 202, 204 based on the operational status. For example, where the operational status is dependent on the rate of communication between the modules 202, 204, a lower than expected data rate may be indicative of issues arising due to the barrier 208. An adjustment may be applied to the control of the communication modules 202, 204 to compensate for the lower than expected data rate, thereby resolving issues with known systems. The adjustment may, for example relate to a correction of the power provided by one or both of the power supplies 218, 220 and / or signal levels of the communication signal between modules 204, 206.

[0198] In a further embodiment, the operational status may relate to the power transfer between power supply units 218, 220. In a further embodiment, the operational status of one set of components may be inferred from the operation of another component, such as a communication rate between optical / RF front ends may be used to infer the operational status of the power supply units 218, 220.

[0199] The status detection unit 200 may be configured to determine one or more properties of the barrier 208 based on the determined operational status. For example, a specific power transfer rate and / or data communication rate may be indicative of the barrier type. The one or more properties of the barrier 208 may include barrier composition, barrier thickness, number of barriers, distance between barriers, type of coating on the barrier, number of coating layers of each barrier, temperature, and intactness of the barrier.

[0200] The status detection unit 200 may be configured to adjust one or both of the communication modules 202, 204 based on the barrier property or properties, thereby adjusting based on the operational status.

[0201] In a specific embodiment, a control signal may be provided by the status detection unit 200 to control the appropriate component or components to apply the adjustment to one or both the communication modules 202, 204. If the status detection unit 200 is located on the opposite side of the barrier to the module 202, 204 to be controlled, the control signal may be transmitted wirelessly through the communication link between the modules 202, 204 or through a separate wireless communication system having modules on either side of the barrier 208.

[0202] Figure 3(a) is a schematic of a further specific embodiment of the status detection unit 200 and the wireless communication system 202 of Figure 2(a) in accordance with a sixth embodiment of the present disclosure. It will be appreciated that the additional features of the present embodiment may be applied to any of the other embodiments described herein in accordance with the understanding of the skilled person.

[0203] The status detection unit 200 comprises a test signal transmitter 300 configured to transmit a test signal 302 and a test signal sensor 304 configured to detect the test signal 302 after reflection by the barrier 208. The operational status may be determined by analysing the test signal 304 after reflection, and the one or more properties of the barrier 208 may be determined based on the operational status determined from the test signal 304. As shown in the schematic, in a specific embodiment, the test signal 302 may be reflected from both interfaces of the barrier 208. The status detection unit 200 may be configured to perform a time of flight measurement using the test signal 302 to determine the operational status. The status detection unit 200 may measure the thickness of the barrier 208 by sending out the test signal 302 and measuring the time of flight of the reflection from either 1) the furthest away glass-barrier surface, e.g. if the barrier surface is double or triple glazed windows; or 2) an opposing module. Reflection from each module may be achieved by coating one or both modules with a reflective material.

[0204] The test signal 302 may be one or both of an optical or acoustic signal. Preferably, the test signal 302 is optical when the barrier 208 is glass or low emission class, in particular double or triple glazed low emission glass windows. In such an embodiment, the transmitter 300 may be a white light LED. Preferably if the barrier 208 is glass, white light LED may be irradiated onto the glass barrier surface to provide a spectral reflectance curve. This spectral reflectance curve can identify the type of glass, for example softlow-Emission coated glass or hard low-E coated glass.

[0205] The status determination unit 200 may be configured to determine the one or more properties of the barrier 208 using software, algorithms, artificial intelligence with machine learning and / or pilot tones.

[0206] The status detection unit 200 may be configured to adjust one or both of the communication modules 202, 204 based on the barrier property or properties, for example by providing feedback control to the internal power supply units 218, 220 to ensure sufficient power is transferred through the barrier 208, for example, with an inductive power transfer system by changing the power coil size. The status detection unit 200 may correlate signal output and the reflected signal strength to barrier numbers.

[0207] Figure 3(b) is a schematic of a further specific embodiment of the status detection unit 200 and the wireless communication system 202 of Figure 2(a) in accordance with a seventh embodiment of the present disclosure. It will be appreciated that the additional features of the present embodiment may be applied to any of the other embodiments described herein in accordance with the understanding of the skilled person. In the present embodiment, the status detection unit 200 is configured to determine an operational status of the communication system 202 based on the power exchange rate between the power supply unit 218 and the power supply unit 220.

[0208] Figure 3(c) is a schematic of a further specific embodiment of the status detection unit 200 and the wireless communication system 202 of Figure 2(a) in accordance with an eighth embodiment of the present disclosure. It will be appreciated that the additional features of the present embodiment may be applied to any of the other embodiments described herein in accordance with the understanding of the skilled person. In the present embodiment, the status detection unit 200 is configured to determine an operational status of the communication system 202 based on the rate of communication between the communication modules 204, 206.

[0209] Figure 3(d) is a schematic of a further specific embodiment of the status detection unit 200 and the wireless communication system 202 of Figure 2(a) in accordance with a ninth embodiment of the present disclosure. It will be appreciated that the additional features of the present embodiment may be applied to any of the other embodiments described herein in accordance with the understanding of the skilled person. In the present embodiment, the module 204 comprises a temperature sensor 306, and / or the module 206 comprises a temperature sensor 308. The status detection unit 200 is configured to determine an operational status of the communication system 202 based on the temperature of one or both of the communication modules 204, 206.

[0210] The operational status may be one or more of the rate of communication, the power exchange, or the temperature of one or both of the modules 204, 206. In a further embodiment, the operational status may be derived from one or more of the rate of communication, the power exchange, or the temperature of one or both of the modules 204, 206. Figure 3(e) is a schematic of a further specific embodiment of the status detection unit 200 and the wireless communication system 202 of Figure 2(a) in accordance with a tenth embodiment of the present disclosure. It will be appreciated that the additional features of the present embodiment may be applied to any of the other embodiments described herein in accordance with the understanding of the skilled person.

[0211] In the present embodiment, the status detection unit 200 is configured to receive data relating to the efficiency and / or input-output voltage of the power supply unit 218 and the power supply unit 220, and calculate the gain and / or attenuation of the communication modules using the received data, and adjust the communication module 204 and / or the communication module 206 based on the calculated gain and / or attenuation. By doing this calculation, the status detection unit 200 can optimise communication across the barrier 208. Communication of the status detection unit 200 with the power supply units 218, 220 may be by an analog or a digital signal.

[0212] Figure 3(f) is a schematic of a further specific embodiment of the status detection unit 200 and the wireless communication system 202 of Figure 2(a) in accordance with an eleventh embodiment of the present disclosure. It will be appreciated that the additional features of the present embodiment may be applied to any of the other embodiments described herein in accordance with the understanding of the skilled person.

[0213] In the present embodiment, the status detection unit 200 comprises a status detection module 310 coupled to the communication unit 204, and a status detection module 312 coupled to the communication unit 206. The detection modules 310, 312 are configured to communication through the barrier 208, for example bidirectionally, and for example, using the Transmission Control Protocol (TCP). Data may be communicated between modules 310, 312 using a method that guarantees data is received, or using a method that does not guarantee data is received. The detection modules 310, 312 may communicate using wireless transmission, for example optical or RF transmission.

[0214] In a specific embodiment, and as discussed previously, a control signal may be provided by the status detection unit 200 to control the appropriate component or components to apply the adjustment to one or both the communication modules 202, 204. If the status detection unit 200 is located on the opposite side of the barrier to the module 202, 204 to be controlled, the control signal may be transmitted wirelessly through the communication link between the modules 202, 204 or through a separate wireless communication system having modules on either side of the barrier 208, as may be provided by the modules 310, 312.

[0215] In a specific embodiment, the status detection modules 310, 312 are configured to communicate reference clock data relating to their respective communication modules 204, 206, and to synchronise their respective communication modules 204, 206 based on the reference clock data.

[0216] The status detection modules 310, 312 may communication any correlation between an optical and an electrical channel activity. The status detection modules 310, 312 may communicate data relating to time of flight of test signals 304 and reflection received optical and voltage power.

[0217] In a specific embodiment, the rate of communication between the status detection modules 310, 312 may be used to determine the operational status. For example, the operational status of the power units 218, 220 may be determined by the rate of communication between the modules 310, 312. The operational status from the rate of communication, as determined, may be used to determine one or more barrier 208 properties, as discussed previously.

[0218] Data may be communicated between modules 310, 312 using a method that guarantees data is received, or using a method that does not guarantee data is received. Figure 4(a) is a schematic of a further specific embodiment of the status detection unit 200 and the wireless communication system 202 of Figure 2(a) in accordance with an eleventh embodiment of the present disclosure. The status detection unit 200 may be implemented in accordance with any of the embodiments described herein, and in accordance with the understanding of the skilled person.

[0219] Figure 4(b) is a schematic of a further specific embodiment of the status detection unit 200 and the wireless communication system 202 of Figure 2(d) in accordance with an twelfth embodiment of the present disclosure. The status detection unit 200 may be implemented in accordance with any of the embodiments described herein, and in accordance with the understanding of the skilled person.

[0220] In further specific embodiments, one or both of the OFEs of any of the embodiments described herein may each comprise a plurality of transmitters and / or a plurality of receivers. Each of the plurality of transmitters of each OFE may transmit electromagnetic radiation at the same, or at different wavelengths. Each of the plurality of receivers of each OFE may detect electromagnetic radiation at the same, or at different wavelengths.

[0221] In further specific embodiments, one or both of the modules 204, 206 of any of the embodiments described herein may each comprise a plurality of OFEs, where each of the OFEs comprises one or more transmitters and / or one or more receivers. The transmitters may transmit electromagnetic radiation at the same, or at different wavelengths. The receivers may detect electromagnetic radiation at the same, or at different wavelengths.

[0222] Figure 5(a) is a schematic of the status detection unit 200 and a wireless communication system 500 in accordance with a thirteenth embodiment of the present disclosure. The status detection unit 200 may function as described for any of the embodiments described herein, and in accordance with the understanding of the skilled person. In the present example, an OFE 501 comprises a plurality of transmitters comprising the transmitter 210 and a transmitter 502. It will be appreciated that in further embodiments, the OFE 501 may comprise more than two transmitters.

[0223] In the present example, the OFE 501 comprises a plurality of receivers comprising the receiver 212 and a receiver 504. It will be appreciated that in further embodiments, the OFE 126 may comprise more than two receivers.

[0224] Each of the transmitters and / or receivers of the OFE 501 may function at the same wavelength, for example by transmitting / receiving the same wavelength of electromagnetic radiation. In further embodiments, each of the transmitters and / or receivers of the OFE 501 may function at different wavelengths, for example by transmitting / receiving different wavelengths of electromagnetic radiation.

[0225] In the present example, an OFE 503 comprises a plurality of transmitters comprising the transmitter 214 and a transmitter 506. It will be appreciated that in further embodiments, the OFE 503 may comprise more than two transmitters.

[0226] In the present example, the OFE 503 comprises a plurality of receivers comprising the receiver 216 and a receiver 508. It will be appreciated that in further embodiments, the OFE 503 may comprise more than two receivers.

[0227] Each of the transmitters and / or receivers of the OFE 503 may function at the same wavelength, for example by transmitting / receiving the same wavelength of electromagnetic radiation. In further embodiments, each of the transmitters and / or receivers of the OFE 503 may function at different wavelengths, for example by transmitting / receiving different wavelengths of electromagnetic radiation.

[0228] It will be appreciated that each of the plurality of transmitters and / or receivers of each of the OFEs 501, 503 may function substantially as described for the individual transmitters and receivers of the embodiments described herein. Additional embodiments having a plurality of transmitters and / or receivers may include additional features outlined in relation to the other embodiments described herein, in accordance with the understanding of the skilled person.

[0229] Figure 5(b) is a schematic of the status detection unit 200 and a wireless communication system 505 in accordance with a fourteenth embodiment of the present disclosure. The status detection unit 200 may function as described for any of the embodiments described herein, and in accordance with the understanding of the skilled person.

[0230] In the present example, the module 204 comprises an additional OFE 510 comprising the transmitter 502 and the receiver 504, and the module 206 comprises an additional OFE 512 comprising the transmitter 506 and the receiver 508. It will be appreciated that in further embodiments there may be provided more than two OFEs in one or both of the modules 204, 206, with each of the OFEs comprising at least one transmitter and / or at least one receiver.

[0231] Additional embodiments having a plurality of OFEs for each of the modules 204, 206 may include additional features outlined in relation to the other embodiments described herein, in accordance with the understanding of the skilled person.

[0232] In specific embodiments of the present disclosure, the or each transmitter may comprise a light source, optionally a light emitting diode (LED), an array of LEDS, a laser, for example a VCSEL (vertical-cavity surface-emitting laser), a VCSEL array, or a laser diode, or an LEP (light- emitting plasma). The or each transmitter may be configured to transmit infra-red light and / or visible light and / or ultra-violet light and / or any wavelength(s) of light suitable for OWC communication. The OWC communication may comprise LiFi communication. The OWC communication may be full-duplex and / or half-duplex. The OWC transmission device may comprise or form part of an OWC transceiver device comprising OWC transmitter(s) and receiver(s). The or each transmitter may comprise or form part of an OWC transceiver. In specific embodiments of the present disclosure, the optical front end may comprise a photodetector configured to receive light and to produce detection signals in response to the received light. In specific embodiments of the present disclosure, the optical front end may further comprise receiver circuitry configured to receive and process the detection signals to produce the receiver signals. In specific embodiments of the present disclosure, the optical front end may be configured to detect light and optical wireless communication signals carried by light and produce electrical receiver signals based on the detected light.

[0233] In specific embodiments of the present disclosure, a transmitter and receiver may form a transceiver. The transceiver may have an OWC transmitter optical front end module and an OWC receiver optical front end module. The transmitter optical front end module may also be referred to as the transmitter optical front end. The receiver optical front end module may also be referred to as the receiver optical front end. The transmitter optical front end module and the receiver optical front end module may form part of an optical front end of a transceiver. The receiver optical front end module may have a photodetector and associated receiver optical front end circuitry. Each transceiver may have an optical front end that includes the components of receiver optical front end module and the transmitter optical front end module.

[0234] In summary, embodiments of the present disclosure may be used to determine the operational status of a wireless communication system used to communicate through a barrier. The operational status may then be used to determine an appropriate corrective action to apply to correct the issues, for example relating to non-optimal data transfer rates and / or non-optimal power transfer rates, between communication modules. Specific embodiments may then be used to correct for these issues by adjusting the control of the communication modules appropriately. The operational status of the system may be determined or used as part of an automatic calibration process for calibrating the system on installation. In the following description, embodiments in which the system is calibrated are described.

[0235] Figure 6 depicts a system 600 in accordance with a further embodiment. As described above, the system has two communication modules referred to as a first communication module 604 and a second communication module 606. In the embodiment of Figure 6, the first communication module 604 has a power supply unit 618 and the second communication module 606 has a power supply unity 620, as described with reference to Figure 2. In this embodiment, the power supply unit 618 is configured to wirelessly supply power to the power supply unit 620. As described above, this is of particular benefit for the above example where the module 604 is placed within a property with access to a mains power supply, which is not easily accessible for the exterior module 606.

[0236] The first communication module has an optical front end 601. The first communication module has a modem 640, and a processor in the form of a controller 654. The modem 640 may be a baseband processor, in accordance with embodiments. The controller 654 may be a microcontroller. In addition to the optical front end 601 configured to perform optical wireless communication with the corresponding OFE 603 of the second communication module, the first module has a further wireless communication device 658. The controller 654 is configured to control the modem 640, OFE 601 and further wireless communication device 658. In addition, the first communication module 604 has or is connected to a storage resource 660 for storing a diagnostics log for the system.

[0237] As described with reference to the first module 604, the second communication module 606 has an optical front end 603, a modem 638, controller 652. In addition to the optical front end 603 configured to perform optical wireless communication with the corresponding OFE 601 of the second communication module, the second module has a further wireless communication device 656. The controller 652 is configured to communicate with the modem 638, OFE 603 and further wireless communication device 656.

[0238] The wireless communication devices 656, 658 are configured to form a wireless communication link. In embodiments, system control messages are sent over the wireless communication link. The further wireless communication devices may comprise any suitable wireless communication devices or interface. For example, the wireless communication device or interface may be an RF device. In embodiments, the further wireless communication devices may be RF front ends.

[0239] In embodiment, the further wireless communication link may be a Bluetooth connection, a WiFi connection, a proprietary communication link, near filed communication (NFC) or magnetic induction link. In further embodiments, a secondary optical channel may be used. In some embodiments, the further wireless communication link may re-used the primary optical channel. In some embodiments, the further wireless communication link may use an acoustic signal, for example, an ultrasonic link.

[0240] In some embodiments, each module is configured to measure a temperature, for example, of their respective OWC and communicate temperature information with the controller.

[0241] A calibration process for the system is described with reference to Figure 7, in accordance with an embodiment. Figure 7 depicts the first communication module 704, in Figure 7 this is an indoor unit (1DU) and a second communication module 706, in Figure 7, this is an outdoor unit (ODU). The calibration process can be grouped into an initialisation process 712 and a subsequent operational parameter selection process 714. The operational parameter selection process may also be referred to as a channel estimation process. It will be understood that, in the present embodiment, the method of Figure 7 is performed by the respective controllers of the indoor and outdoor units. In the embodiment of Figure 7, the operational parameters for the module will be understood as the AC and DC bias values for their respective optical front ends. In some embodiments, the operational parameter selection process 714 is performed in response to successful completion of the initialisation process 712.

[0242] In accordance with embodiments, a purpose of the calibration is to choose optimal AC and DC values. In these embodiments, the DC bias relates or corresponds to an average optical power. The AC values relate to peak to peak swing which may be considered to be the actual signal power.

[0243] At step 716, the process starts. At a first step 718a, 718b, each of the indoor and outdoor unit set initial values of the operational parameters (AC-DC value pair). In this embodiment, the initial values correspond to a minimum power level.

[0244] In some embodiments, an alternative starting point may be used. For example, initial values that provide an intermediate or average point between a minimum and maximum power level may be selected.

[0245] Following this step the two modules establish a further wireless communication link via their respective further wireless communication devices. In the present embodiment, the ODU waits, at step 720, to receive a synchronised start signal from the IDU via the further wireless communication link. At step 722, the IDU waits for confirmation that a power supply is provided. This may be received from a power supply.

[0246] In response to receiving a power supply confirmation signal, at step 722, the synchronised start signal is sent from the IDU to the ODU using the further wireless communication device. The power supply confirmation signal may come from any power management system and represents that both modules are powered and the calibration can start synchronously on the indoor and outdoor unit. At step 724, the ODU monitors for the received signal via its respective further wireless communication device. In response to receiving the start signal, the ODU sends an acknowledgement signal, at step 724, to the 1DU unit via the further wireless communication link. Following reception of the start signal, the ODU starts to perform part of the operational parameter selection process at step 730. At step 726, the 1DU monitors for reception of the acknowledgment signal. In response to receiving the acknowledgement signal, the 1DU is aware that the ODU is present and the 1DU continues to perform part of the operational parameter selection process commencing at step 732.

[0247] After steps 724 and 726, the further wireless communication link between the two modules is established. In response to establishing this further link, the operational parameter selection process 714 starts at steps 730 and 732, respectively.

[0248] The operational parameter selection process may be performed, for example, with reference to Figure 8. The operational parameter selection process includes performing a channel estimation algorithm to obtain, for example, by sensing or measuring, one or more properties of the OWC channel between modules dependent on operational parameters and selecting operational parameters that provide desired or optimum OWC channel characteristics.

[0249] For the ODU, the controller monitors to determine if the channel estimation process is successful, at step 734a. As described in further detail, for example, with reference to Figure 8, the channel estimation process results in determination of optimum values of the operational parameter. In response to successful determination of the channel estimation process, the controller sets the operational parameters to those determined optimum values at step 736a.

[0250] If the estimation process is not successful, the ODU first repeats the channel estimation process. On the second process, if successful the method process to step 736a. If unsuccessful on the second attempt (Step 738a), the channel estimation process to set the operational parameters to default values, at step 740a. The IDU is configured to perform a channel estimation process in a similar fashion. Steps 734a, 736a, 738a, 740a, 742a will be understood to correspond to steps 734b, 736b, 738b, 740b, 742b performed by the IDU and are not described in detail, for brevity.

[0251] Following successful channel estimation process, the system starts normal operation at steps 742a and 742b. The method stops following commencement of normal operation at step 744.

[0252] In some embodiments, the channel estimation process for IDU and ODU are performed simultaneously. In some embodiment, the channel estimation process is performed for a transmitter of one of the two modules then for the transmitter of the other of the two modules. In some embodiments, a confirmation signal may be sent, either via the OWC channel or the further wireless communication link to confirm that the ODU or IDU has completed the channel estimation process.

[0253] Figure 8 depicts an operational parameter selection process including a channel estimation process, in accordance with an embodiment. In this embodiment, the method of Figure 8 is being performed on the first module, but it will be understood that the same process can be performed using the second module. The process of Figure 8 obtains optimum values for operational parameters, in this embodiment, AC and DC pair values, by performing multiple sweeps through parameters. In this embodiment, the system is configured to perform a first coarse sweep process 802, a second stage sweep 804 and a third fine sweep 806. It will be understood that the method of Figure 8 can form part of a calibration process workflow, such as the process depicted in Figure 7.

[0254] Briefly, the first coarse sweep process results in obtaining initial coarse values for the operational parameters. In particular, the aim is to find operational parameters that at least establish an OWC connection across the barrier. These are then refined in the second and third stages to find optimum values for these operational parameters. In some embodiments, the result is finding parameters that provide a sufficiently high speed or high quality OWC channel. For example, the process may continue until parameters are found that provide an OWC channel with desired properties such as a data rate above a threshold. The third sweep stage, optionally the second sweep stage, use an iterative feedback process to refine the operational parameter based on the determined line rate.

[0255] The process may be considered to explore an operational parameter space. In the present embodiment, the parameter space is a 2 dimensional vector space, where the AC and DC parameters correspond to an x and y axes in a 2 dimensional vector space. The first coarse sweep corresponds to jumping between pre-determined points in the parameter space. An example is depicted in Figures 16(a) to (c). For example, these may correspond to points on a lines or curve in the parameter space. The result of the first sweep is selection of one of those points. The second and third finer sweeps can be considered to iteratively explore regions in parameter space about that first selected point to find an improved data rate.

[0256] In some embodiments, the calibration process includes a first coarse sweep in which one or more properties of the OWC channel are estimated and / or determined along pre-determined points defined on a line or curve or surface in the parameter space. Following determination of the point providing the best OWC performance (for example, the highest link speed or other desired parameter) one or more further stages of refining the point is performed. The refining stage may include exploring a region about the first point to find improve performance.

[0257] The process starts at step 808 and starts the coarse sweep. The coarse sweep sequentially selects a pair of AC-DC values from a plurality of pre-determined AC- DC value pairs and determines the operational status for the system using those AC- DC values. Determining the operation status may include determining one or more properties of the OWC channel forms between the two modules, specifically between their OWC front ends. In the present embodiment, the AC-DC value pair providing the highest data rate is selected as the initial AC-DC values for the second stage.

[0258] In further detail, at step 810, a first pair value is selected from a set of predetermined pair values. The operational parameters are set to those values and an OWC signal is generated and transmitted from the first module (in this embodiment) to the second module using the AC-DC value.

[0259] At step 812, a TX line rate is obtained. It will be understood that a dwell time is set to be sufficiently long to allow the baseband to update. At step 816, the determined line rate is saved in a results table. This may be saved in storage resource provided in the module. The TX line rate will be understood to be a measured and reported by the modem, in embodiments, a g.hn baseband chip. Alternative measures of data rate may be reported by the modem 638 to controller 652. The dwell time may be understood as the time between setting the operational parameters, in this case the AC-DC value pairs and obtaining the TX line rate reading.

[0260] At step 818, the method proceeds to the next AC-DC value pair in the set of AC-DC value pairs.

[0261] At step 820, it is determined whether the line rate has been determined for all AC- DC pairs. If not, the method returns to step 810 in which the operational parameters are set to the next AC-DC value pair. A line rate is then determined for the next AC- DC value pair (step 812) and then stored (at step 816) followed by selection of the next AC-DC pair of the set.

[0262] If, at step 820, it is determined that all AC-DC pairs have been evaluated, for example, by checking the stored results table for results for all AC-DC pairs, the method process to step 822 in which the highest line rate is found in the results table. The highest line rate is then set (the variable may be referred to as the initial AC-DC pair value or “coarse max”). Following completion of the coarse sweep, an initial value pair (“coarse max”) is obtained and the method proceeds to the second stage sweep 804.

[0263] The second stage sweep is similar to the first stage sweep, in that the point giving the best reported line rate is selected as the starting point and further predetermined pairs are selected around the initial starting point. At step 824, a first pair is selected, the Tx line rate determined at step 826 and then stored in results table at step 828. This process is repeated until the pre-determined pairs are all tested (step 830). In completed, the maximum line rate is determined from the stored results at step 832.

[0264] Following completion of the second stage sweep, at step 834, a check of the second stage sweep results is performed. At step 834, it is determined whether the result of the second stage satisfies a data rate condition. For example, the data rate condition may be that the data rate is above a pre-determined threshold value. The result of the second stage may offer an OWC channel with a sufficiently high data rate such that the third stage is not needed or would only offer a small improvement. If the second stage result satisfies the data rate condition then the method proceeds to the final step using the result of the second stage sweep as the selected AC-DC pair. If the second stage result does not satisfy the data rate condition, the method proceeds to the third stage.

[0265] The third stage applies a refining process to determine an optimum AC-DC pair value based on the result from the earlier stage. In some embodiments, the third stage applies a feedback loop in which the AC-DC pair value is iteratively adjusted to explore available line rates in a region in AC-DC parameter space defined about the result from the second sweep. The parameter space of the region can be explored using different strategies, in accordance with embodiments.

[0266] In some embodiments, a region is swept in a square grid around the starting point. By not restricting this sweep to pre-determined pairs, hardware variable and tolerance build up may be accounted for. In further detail, at step 836, a first AC-DC value is selected based on the result from the second stage. At step 838, a line rate is obtained then stored (at step 840) as described with reference to step 812 and 816. Steps 838, 840 and 844 will be understood to form a refining strategy in which the results are refined. In contrast to stages one and two, the points are now taken from pre-determined values bu rather swept from a region drawn about the result from the second stage.

[0267] At step 842, it is checked that the final sweep is completed. If not, the process selects a new value for AC-DC pair and returns to step 836. If the final sweep is completed, the process moves to step 844 in which the maximum line rate for the region is determined.

[0268] At step 846, the AC-DC parameters are set to the final values determined through the method of Figure 8. Figure 16 depicts the different stages of a sweep strategy in accordance with an embodiment.

[0269] In the embodiments described above, a further wireless communication link was described for an initialisation process 712. In an alternative embodiment, an alternative initialisation process is performed that does not require the establishment of the further wireless link.

[0270] An embodiment without the further wireless link is depicted in Figure 9. In operation, the indoor unit starts first and monitors for a further unit to start drawing wireless power. In the embodiment of Figure 9, system control messages and data can be sent between OFE and modem, and may be sent via the main OWC channel between modules, rather than by a back-channel or further wireless link.

[0271] As described with reference to Figure 6, the system of Figure 9 has a first module 904 and a second module 906 and the first module has an OFE 901, a modem 940, a controller 954 and a wireless power module 918 and the second module has a OFE 903, a modem 938, a controller 952 and a wireless power module 920. In contrast to Figure 6, the system does not have a further wireless link. Instead, in response to sensing wireless power being drawn, the indoor unit starts the calibration process, substantially as described with reference to Figure 7 and 8. The outdoor unit automatically starts the calibration process on start-up. In some embodiments, the outdoor module starts the calibration process in response to receiving wireless power from the indoor unit.

[0272] In a further embodiment, both modules start with pre-determined values of the operational parameters, for example, AC-DC pairs (for example, values that give basic connectivity across all window and barrier types). Both modules then monitor for connectivity across the OWC link and then the calibration procedure commences in response to detecting connectivity. The connectivity is monitored based on feedback from the modem / baseband.

[0273] It will be understood that the initial starting values will be dependent on the optical front end being used. However, in general, an AC-DC range may be established and intermediate values selected from that range (for example, mid-point values) that offer basic connectivity.

[0274] In the above-described embodiments, the OWC calibration process was performed by controlling operational parameters of the optical front end, specifically the AC- DC value pairs. It will be understood that other operational parameters of each module may be used to calibrate OWC communication between the two modules.

[0275] In further embodiments, an electronic test signal generator and detector is provided in each module. Figure 10 depicts an embodiment of the system 1000. For brevity like reference numerals refer to like components when compared to Figure 6.

[0276] In comparison to Figure 6, each module has a dedicated tone generator and detector and switching component. The first module 1004 has a tone generator and detector 1062 and electronic signal switch 1064 and the second module has a tone generator and detector 1070 and electronic signal switch 1068. The switches can be any suitable switching device that is controllable.

[0277] As depicted in Figure 10, with reference to the second module 1006, the switch is configured to switch between a first configuration in which the modem 1038 is coupled to the OFE 1003 and a second configuration in which the tone generator 1070 is coupled to the OFE 1003. The tone generator is configured to produce an electronic tone signal for the optical front end, for example, a simple sinusoidal signal. Each device is configured to perform a calibration process to determine optimum or suitable operational parameters for the optical front end using tone signals.

[0278] Embodiments using separate signal generation and detection, may offer benefits, if, for example, the specific modem in the system was not reporting telemetry data (including line rate and connectivity data). As such, the calibration method is independent of the type of modem (baseband) being used).

[0279] Figure 11 depicts, in further detail, an embodiment in which a tone generator forms part of calibration circuitry. Similar to Figure 10, Figure 11 has a first module 1104 and second module 1106. In this embodiment, the second module 1106 has a baseband processor 1138, a tone generator 1170, a switch 1168, signal conditioning circuitry 1169, a transmitter 1171 and a controller 1152. The tone generator 1170, switch 1168 and signal conditioning circuitry 1169 are referred together as transmitter channel estimation circuitry 1153 (CEM TX). The transmitter and receiver may be referred to as light antenna modules (LAM).

[0280] In this embodiment, the first module 1104 has a baseband processor 1140, a detector 1162, a switch 1164, signal conditioning circuitry 1165, a receiver 1173 and a controller 1174. The switch 1164, signal conditioning circuitry 1165, and detector 1162 are referred to as receiver channel estimation circuitry 1155 (CEM TX). As shown in Figure 11, in this embodiment, the optical front end for the second module 1006 has a transmitter 1171 and associated transmitter circuity. In this embodiment, the associated transmitter circuitry includes signal conditioning circuitry 1169. In the present embodiment, the calibration process obtains operational parameters for the signal conditioning circuitry. It will be understood that, in further embodiments, the calibration process obtains operational parameters for other components of the module, for example, for both the signal conditioning circuitry and the transmitter. It will also be understood that each module may have corresponding transmitter and receiver components, but that Figure 11 depicts only one pair of transmitter and receiver circuitry. Figure 13 depicts an embodiment in which both modules have transmitter and receiver circuitry.

[0281] In this embodiment, the controller of each module communicate via a back-channel, for example, via further wireless communication channel 1172. In Figure 11, the controllers require a back channel. However, in alternative embodiments, the process may be carried out without a back channel, for example, by relying on a synchronous start message, so both sides start the calibration at the same time.

[0282] Figure 12 depicts a calibration routine using test signals, signal conditioning circuitry and detectors to estimate channel characteristics and adjust transmission or driving / receiving circuitry accordingly.

[0283] In the method of Figure 12, it will be understood that both modules are configured to co-operate to perform a channel estimation process including determining an operational parameter for the transmission side. It will be understood that one module sends OWC test signals that vary based on an operational parameter to the other module and a determination of the optimum parameter is determined based on one or more measured properties of the received signal at the other module. In the present embodiment, the operational parameter is an attenuation parameter for the signal conditioning circuitry and the measured property is an analogue to digital converter ADC reading at the receiver side. Following successful determination of the attenuation parameter that parameter is set for the module being calibrated. A further calibration process may then be performed for the other module. Alternatively, in some embodiments, the determined parameter for the first module (determined during a first calibration stage) is set for the second module.

[0284] Figure 12 depicts a method of calibration in accordance with an embodiment. The system described above has a first and second communication module capable of OWC transmission and reception. For the purposes of the following description, the calibration of the transmission mode of one of the two modules is described. It will be understood that, following successful calibration of the first module, the process may be repeated for the other of the two modules.

[0285] In the following description the module being calibrated is referred to as the transmitting module and the other of the two modules is referred to as the receiving module. As described above, the transmitter module is operable to be in a first mode in which the tone generator 1170 is connected to the signal conditioning circuitry 1169 (calibration mode) and a second mode (communication mode) in which the baseband processor 1138 is connected to the signal conditioning circuitry 1169. Likewise, the receiver module is operable to be in a first mode (calibration mode) in which a detector (or other measurement device) 1162 and signal conditioning circuitry 1165 is connected to the receiver 1173 and a second mode (communication mode) in which the baseband processor 1140 is connected to receiver 1173.

[0286] In the following embodiment, the test signal is a sinusoidal wave having a predetermined frequency. The frequency may be within the operational bandwidth of the OFE. In accordance with embodiments, this is between 50 kHz to 400 MHz. In the present embodiment, the frequency is 5 MHz. In the embodiment described in Figure 12, the signal conditioning circuitry comprises a programmable attenuator. While the determination of a value for the programmable attenuator is described, in some embodiments, more than one operational parameter may be determined through the calibration process. For example, a parameter of the signal conditioning circuitry may be determined together with a parameter of the transmitter optical front end, for example, an adjustable bias current.

[0287] In accordance with embodiments, the signal conditioning circuitry may comprise at least one controllable component that changes a characteristic of the OWC channel. In accordance with embodiments, the controllable component may be a filter, attenuator, amplifier, balun, logarithmic amplifier, splitter, switch.

[0288] Likewise, in accordance with embodiments, the detector may comprise or be provided together with at least one measurement device for measuring at least one property of the OWC channel. Without limitation, the measurement device may comprise an ADC and sampling circuitry, a peak detector or, for example, an RMS detector.

[0289] At steps 1202a and 1202b, the two modules start the calibration process. The start is co-ordinated by the further wireless link between the two modules. Both modules are powered up and begin in calibration mode.

[0290] At step 1204, the transmitter module selects an initial value for the operational parameter. In the present embodiment, the operational parameter is an attenuation parameter of the signal conditioning circuitry. In the present embodiment, the attenuation parameter is set to a maximum possible value.

[0291] At step 1206, the transmitting module sends an optical test signal. In detail, an electronic tone signal is generated and provided to the TX optical front end via the controllable attenuator. The signal provided to the optical front end is therefore conditioned in accordance with the calibration parameter. In this embodiment, the tone signal is attenuated by the attenuating parameter before being received by the TX optical front end.

[0292] At step 1208, the receiving module receives the optical test signal and measures a property of interest of the received optical signal. In the present embodiment, the property of interest is an output of an analogue to digital converter and the measurement comprises sampling the ADC output. In further detail, the received optical test signal is received by the receiver and converted into an electronic receiver signal. The electronic receiver signal is provided to the signal conditioning circuitry and then to the detector circuitry. In the present embodiment, the detector circuitry comprises an ADC and converts the analogue signal to a digital signal.

[0293] At step 1210, the value of the ADC sample is processed by the controller circuitry of the module(s). In some embodiments the value of the ADC sample is sent back to the transmitting module as a result signal via a further wireless communication channel.

[0294] At step 1212, the result signal is received by the transmitting module. The result signal is then processed by the controller of the transmitting module. In some embodiments, the gathered information comprises a voltage or set of voltage that is sent to an ADC pin or set of pins of the microcontroller.

[0295] At step 1214, the measured quantity is stored. In the present embodiment, the result is stored in a buffer. In addition, the ADC sample result is stored together with the attenuation parameter value in a log file.

[0296] At step 1216, an evaluation of the measurement is performed to determine if a calibration condition has been met. This step may comprise comparing all stored results to determine an optimum operational parameter. In the present embodiment, the calibration condition is determining whether a peak in the ADC sample has been identified. In this step, a peak detection process is performed. If the calibration condition has not been found, the calibration process returns to step 1204, where a further value of the operational parameter is selected. In this embodiment, the attenuation parameter is reduced by a pre-determined amount.

[0297] If the calibration condition has been met, the calibration process proceeds to step 1218, where the operational parameter is stored for later use or set for immediate use. In the present embodiment, at step 1218, the mode of the module is set to communication mode, and the switch is controlled to couple the baseband processor to the signal conditioning circuitry.

[0298] The iterative process between steps 1204 and 1216 may be limited by a predetermined parameter limiting the number of iterations. In addition, in some embodiments, a buffer stores recent measurement results (for example, the previous 3 readings). If the measurement result is the same as the previous 3 results in the buffer, the calibration method ends in a fault.

[0299] In some embodiments, a timer may be set to measure the calibration time and may be logged. If the calibration timer reaches a pre-determined timeout or if any other component of the modules are not functioning properly, the calibration process may end with a fault.

[0300] The calibration process ends at step 1222. Following the ending of the calibration process, the method of Figure 12 may, in some embodiments, be repeated for the other of the two modules.

[0301] In the above described embodiments, the evaluation of results is performed at the controller of the transmitting module. In some embodiments, the evaluation is performed at the receiving module and, in place of a result signal representing the measured quantity, a signal instructing the transmitting module to change the operational parameter is sent. For example, the receiving module may determine if the OWC channel has good performance based on the measured property, for example, above a threshold value, and if the OWC channel does not have good performance the receiver module selects a new value for the operational parameter or instructs the transmitter module to select a new value.

[0302] In a further embodiment, the test signal is a pure sine wave of a known frequency, the signal conditioning is a programmable attenuator and OFE bias adjustment circuit. The RX signal conditioning may be a balun, amplifier and bandpass filter and the detector is a peak detector and ADC. The measured information at the receiver end may be the ADC data and the calibration condition may be based on ADC data. In some embodiments, a look-up table may be used to determine whether the measured magnitude indicates adjustment of the TX signal is required (i.e. adjustment of attenuation and / or DC bias). In some embodiments, the calibration runs until the condition is met or the system reaches a time out state.

[0303] In some embodiment, temperature compensation may be performed by adjusting one or more operational parameters, such as the signal conditioning circuits. In such embodiments, the temperature compensation may be performed using the further wireless communication link.

[0304] In some embodiments, the measured data may be an amplitude of a frequency component of the received optical signal. In some embodiments, the measured data may be an amplitude of the main frequency component and one or more other frequency components (harmonics). In some embodiments, a sampling of the received waveform may be performed using an ADC with sufficient resolution and sampling frequency. In some embodiments, the sample frequency is at least twice the sampling frequency than the largest harmonic frequency to be represented, optionally with a resolution sufficient to capture all possible amplitudes given the variation of the channel being estimated.

[0305] In embodiments, if we have a high enough sample rate to accurately measure the 2nd and 3rd harmonics of a fundamental test signal, then an optimum operating point may be determined from this alone deduce the optimum operating point from that alone. In accordance with an embodiment, AC-DC pairs are swept on the transmitted side, and a measurement of total harmonic distortion is determined at the receiver side. When the total harmonic distortion goes over a pre-determined value (for example -30 dB) it can be determined that the optimum operating point has passed. From that point, the optimum operating point can be determined. For example, the AC-DC values may be stepped back from the point at which the threshold is passed. The highest AC-DC pair that gives good linearity (for example, corresponding to small THD) can therefore be determined.

[0306] As described above, only the transmission of a first module and the receiver of the second module is depicted in Figure 11. Figure 13 shows an embodiment in which both modules have transmission and receiving modules.

[0307] The first module 1304 has a baseband processor 1340 coupled to channel estimation receiver module 1382a and receiver 1384a (corresponding to CEM RX 1155 and receiver 1173 of Figure 11). The firstmodule also has a channel estimation transmitter module 1386a and transmitter 1388b (corresponding to CEM TX 1153 and transmitter 1171 of Figure 11). Likewise, the second module 1306 has a baseband processor 1338 coupled to channel estimation receiver module 1382b and receiver 1384b and a channel estimation transmitter module 1386b and transmitter 1388b. The channel estimation modules are controlled by the respective controllers of the modules (1352 and 1374). In particular, the controllers are configured to control operational parameters for the respective modules as part of a calibration process. The controllers 1352 and 1374 are in communication via a further wireless link.

[0308] In the above-described embodiments, operational parameters AC and DC values were described. Figure 14 illustrates the AC and DC values with reference to a waveform. As can be seen, the signal or waveform is a time-varying waveform formed by a summation of a non-varying direct current portion and a variable alternating current portion. The value of the DC portion is the DC value. The size of the AC value can be characterised using different methods. In this embodiment, the AC value is the total amplitude of the time varying signal. Both the DC value and the

[0309] AC value can be varied.

[0310] In the present embodiment, the AC is controlled by setting a variable attenuator chip. The AC value is therefore selected by setting values for the variable attenuator chip. As the attenuation goes up, AC signal goes down. In this embodiment, every step in attenuation relates to 0.5 dB reduction in the AC signal.

[0311] The DC value 1402 is the average current flowing through the emitter during transmission. The AC value 1404 is the peak to peak current through the waveform during transmission i.e. during the transmission duration 1406.

[0312] In the following, a parameter space of DC bias and AC values are depicted for different types of barrier, namely, a double pane window with AG2 coating of 18mm thickness (Figure 15(a), an uncoated single pane window of 4mm thickness (Figure 15(b)), a double pane coated with AG1 of 18 mm thickness (Figure 15(c)), a double pane coated with AG3 of 19 mm thickness (Figure 15(d)) and a double pane with a hard coating of 19 mm thickness (Figure 15(e)).

[0313] As can be seen, in Figure 15(a) to (e), the property of the link that is measured to represent the channel performance is the downlink bandwidth in Mbps.

[0314] In each of Figures 15(a) to (e), the downlink bandwidth is measured over the parameter space. The depicted parameter space in each Figure generally has one or more low bandwidth regions (for example, 1502a), one or more intermediate bandwidth region (for example, 1504a) and one or more high bandwidth regions (for example, 1506a). The size, shape and other properties of these regions will vary depending on, for example, optical properties, dimensions and / or coatings and materials of the barrier. As such, it is clear that a calibration process can significantly improve OWC channel performance for the system in situ. In above-described embodiments, the optical front end or signal conditioning circuitry may be controlled to control AC-DC values associated with a transmitted optical signal transmitted between the modules. However, in further embodiments, the AC-DC values may be controlled using other means. As an example, the AC-DC values may be adjusted together, for example, using a lookup table.

[0315] In further embodiments, the AC-DC values may be controlled using an optical control may be provided to optically control AC-DC values of the signal, for example, using tunable / adjustable optics and controlling one or more parameters of the tunable / adjustable optics.

[0316] In a further embodiment, a parameter of the receiver may be controlled, for example, to control the received power instead of or in addition to the transmitter, by changing the received gain, either optically or the detector gain.

[0317] In some embodiments, the generated optical signal can be considered to be formed of a substantially constant time-independent part (i.e. a constant DC portion) and a time varying part (i.e. an AC portion). The operational parameters of the system may be varied such that a parameter space of a value of the time-independent part and a value of the time varying part can be explored.

[0318] Figure 16(a), (b) and (c) depict the different stages of a sweep strategy in accordance with an embodiment.

[0319] In each of Figures 16(a) to (c), a 2D parameter space is depicted. On the x-axis 1602 are AC values and on the y-axis are DC values 1604. Each point in the space can be represented by an AC, DC value pair. In accordance with embodiments, the AC-DC values may be varied across parameter space by controlling parts of the modules, for example, the signal conditioning circuitry, associated optical circuitry and / or the optical front end. Line 1616 represents a line through the parameter space along which predetermined AC-DC value pairs are defined. These pre-determined points and / or the line may be obtained through system characterisation. It is not necessary that this line be linear, however, in this illustrative example this is the case. In some embodiments, the line may be curved or other shape. Each cell of the plots represents a TX line rate value reported by the baseband for that AC-DC pair. The regions 1606, 1608, 1610, 1612, 1614 show the approximate optimum AC-DC value regions for a given glass type that will result in an optimum data rate. These are referred to as: plain glass region 1606, hard coat region 1608, AG1 region 1610, AG2 region 1612 and AG3 region 1614. The shape and size of each region may vary depending on, for example, glass type, total thickness, number of panes and various low-E coating types on the surface.

[0320] It will be understood that, for a given region, a link for that barrier type can be formed outside of these regions with non-optimal data rates. The regions shown above are qualitative and can vary a lot between different models. However, the type of barrier may be determined based on the final selected value. The type of barrier may be determined based on the final or intermediate calibrated AC-DC values, for example, based on which of the pre-determined region the final values lie.

[0321] Figure 16(a) depicts a first coarse sweep stage (corresponding to Figure 8, stage 802) in which a single value on line 1616 from each region is tested. In this embodiment, these are solid dotted points linked by arrows. The coarse sweep therefore test the solid dot in first region 1606 followed by the solid dot in second region 1608 and so on until reaching the solid dot in the final region 1614. The values indicated by the slash sign are skipped, in this embodiment.

[0322] Figure 16(b) depicts a second stage sweep (corresponding to Figure 8, stage 804). The second stage sweep sweeps through AC-DC value pairs corresponding to the slashes around the value pair that gave us the best reported line rate from the baseband during Coarse sweep, in the previous step. In the example of Figure 2, the second stage sweep starts at the solid dot of the third region 1610 (Referred to as point 1622) and then tests points along the original line about this point, in this case point 1626 and point 1624.

[0323] In some embodiments, the pre-determined points for the second stage may be associated with a region. In accordance with an embodiment, each region may have a corresponding set of pre-determined values to be swept through.

[0324] Figure 16(c) depicts a third stage sweep (corresponding to Figure 8, stage 806) in which a region is drawn about the best reported point from the preceding stage. In this embodiment, the region is a 3x3 square region 1628 indicated by crosses drawn around point 1626. In other embodiments, the region may be a different shape, for example, a circle or rectangle. In some embodiments, the optimum line rate in that region may be found using a feedback mechanism, for example, by determining if a new line rate is higher than the line rate of a previous point.

[0325] The term light herein may be used, for example, to refer to electromagnetic waves with wavelengths in a range 1 nm to 2500 nm, which includes ultraviolet, visible light and near-infrared wavelengths. Light may be used to refer to both visible light and non-visible light of any suitable wavelengths.

[0326] In the above-described embodiments, it will be understood that for optical wireless communication, any suitable modulation scheme may be used. In embodiments, the optical signals transmitted between modules comprises optical signals modulated in accordance with a suitable scheme. For example, orthogonal frequency division multiplexing (OFDM) modulation schemes are used in some embodiments, and the demodulation is from the OFDM modulation scheme. In further embodiments and without limitation, other modulation schemes may be used, for example on-off keying (OOK), phase shift keying (PSK), M-ary pulse amplitude modulation (M- PAM), M-ary quadrature amplitude modulation (M-QAM), Discrete Hartley transformation, Wavelet packet division multiplexing (WPDM), Hadamard coded modulation (HCM), pulse-position modulation (PPM), Colour shift keying (CSK), carrier-less amplitude and phase (CAP), or discrete multi-tone (DMT). The light may be modulated at a modulation rate between 1 kHz and 1 PHz, for example at a modulation rate between 1 MHz and 100 GHz. The modulation scheme may form part of an OWC communication protocol, such that the optical signal is produced according to the OWC communication protocol. The OWC communication protocol may be packet-based. In embodiments, one or more of the modules may be configured to connect to a network, for example, via an OWC enabled access point.

[0327] Various improvements and modifications can be made to the above without departing from the scope of the disclosure.

Claims

CLAIMS1. A status detection unit for a wireless communication system comprising a first communication module and a second communication module, the first and second communication modules being configured to communicate using optical wireless communication through a barrier; wherein: the status detection unit is configured to determine an operational status of the wireless communication system.

2. The status detection unit of any preceding claim configured to adjust the first communication module and / or the second communication module based on the operational status.

3. The status detection unit of any preceding claim, wherein the status detection unit is configured to determine an operational status of the wireless communication system based on the rate of communication between the first communication module and the second communication module.

4. The status detection unit of any preceding claim configured to determine one or more properties of the barrier based on the determined operational status.

5. The status detection unit of claim 4 wherein the one or more properties comprises barrier composition, barrier thickness, number of barriers, distance between barriers, type of coating on the barrier, number of coating layers of each barrier, temperature, and intactness of the barrier.

6. The status detection unit of claim 4 or 5 comprising a test signal transmitter configured to transmit a test signal and a test signal sensor configured to detect the test signal from the transmitter after it is reflected by the barrier, the operational status and therefore the one or more properties of the barrier being determined based on the test signal.

7. The status detection unit of any of claims 4 to 6, wherein the status determination unit is configured to determine the one or more properties of the barrier using software, algorithms, artificial intelligence with machine learning and / or pilot tones.

8. The status detection unit of any of claims 4 to 7 configured to adjust the first communication module and / or the second communication module based on the determined one or more properties of the barrier.

9. The status detection unit of claim 8, wherein the status detection unit is configured to determine an operational status of the wireless communication system based one or more of: the rate of communication between the first communication module and the second communication module; the power exchange rate between the first power supply unit and the second power supply unit; and / or the temperature of one or both of the first communication module and the second communication module.

10. The status detection unit of claim 9 configured to determine one or more properties of the barrier based on the determined operational status.

11. The status detection unit of claim 10, configured to adjust the first communication module and / or the second communication module based on the determined one or more properties of the barrier.

12. The status detection unit of claim 11 configured to: receive data relating to the efficiency and / or input-output voltage of the first power supply unit and the second power supply unit; and calculate the gain and / or attenuation of the first and second communication modules using the received data; andadjust the first communication module and / or the second communication module based on the calculated gain and / or attenuation.

13. The status detection unit of any of claims 9 to 12 comprising a first status detection module coupled to the first communication module and a second status detection module coupled to the second communication module.

14. The status detection unit of any preceding claim, wherein the first and second communication modules are configured to communicate through the barrier using an optical wireless communication channel, wherein the first and second modules comprise further wireless communication and / or other circuitry for establishing a further wireless link between the first and second module, wherein at least one of: a) the determined operational status of the system is dependent on the further wireless link and / or communicated between the firstand second modules using the further wireless link; b) the system is configured to perform an initialization and / or calibration process for the OWC channel using the further wireless link c) the system is configured to perform a calibration process for the OWC channel in response to establishing the further wireless link d) the system is configured to send information about the OWC channel over the further wireless link.

15. The unit of claim 14, wherein the further wireless link may comprise at least one of: a wireless power link, Bluetooth or other RF communication, WiFi, near field communication, magnetic induction, further optical channel, acoustic signals.

16. The unit of any preceding claim, wherein the first and / or second modules are further configured to perform a calibration procedure, wherein the calibration procedure comprises determining the operational status of the system and / or determining one or more operating parameters for the first and / or second module based on the operational status of the system and / or determining one or more characteristics of the OWC channel.

17. The unit of any preceding claim, wherein the first and / or second module is configured to perform a calibration procedure comprising: transmitting an optical signal from one of the first and second communication module to the other of the first and second module using the OWC communication channel, wherein the transmitted optical signal is dependent on one or more operational parameters and measuring or sensing a property of the received optical signal and / or a signal derived from the received optical signal at the other of the first and second modules; selecting and / or adjusting the one or more operational parameters based on the measured or sensed property.

18. The unit of claim 17, wherein the operational parameters comprise one or more operational parameters for the OWC communication circuitry and / or an OWC transmitter and / or associated transmitter circuitry and / or optical front end of the modules and / or OWC receiver and / or associated receiver circuity.

19. The unit of claims 17 or 18, wherein the one or more operational parameters comprise one or more parameters associated with values of AC and DC values for an OWC signal; an attenuation parameter or other parameter of a signal conditioning circuit.

20. The unit of claims 17 to 19, wherein the measured or sensed property of the received optical signal and / or a signal derived from the optical signal is representative of at least one characteristic of the OWC channel, optionally, a speed, data rate or signal quality.

21. The unit of claim 20, wherein the measured or sensed property comprises at least one of: a property of a decoded or demodulated signal, optionally a baseband signal, optionally a data rate of the optical wireless communication channel, optionally an up or downlink of the channel.

22. The unit of claim 20 or 21, wherein the sensed and / or measured property comprises a temperature.

23. The unit of the preceding claim, wherein the system is configured to transfer power wirelessly between the communication modules wherein the calibration process is performed in response to the power or energy transfer between modules and / or wherein information associated with the OWC channel is communicated over a wireless power transfer communication link.

24. The unit of any of claims 20 to 23, wherein the one or more measured or sensed properties may comprise at least one of: a) a determined temperature; b) a property of the received optical signal; c) a property of an electronic signal derived from the optical signal,25. The unit of any preceding claim configured to: identify from a plurality of pre-determined points in an operational parameter space, a first point that provides the best OWC channel performance; determine a further point in parameter space based on the first point that provides an improved OWC channel performance.

26. The unit of claim 25, wherein the plurality of pre-determined points are provided along one or more curves, lines or surfaces formed in the parameter space.

27. The unit of claim 25 or 26, wherein the pre-determined points are separated by a distance in the parameter space and wherein determining the further point comprises adjusting the point or otherwise exploring the parameter space in a region about the first point characterised by a dimension smaller than said distance and / or adjusting the first point.

28. The unit of any preceding claim, wherein the system is configured to calibrate the OWC communication channel and / or an operational parameter of the system using optical test signals carrying substantially no data and / or substantially no network data and / or generated using an electronic tone signal.

29. The unit of any preceding claim, wherein the first and / or second module comprises an electronic test signal generator for generating an electronic test signal for the optical front end and a data signal generator, optionally a baseband or other processor, configured to generate a data signal for the optical front end, wherein the first and / or second module is configured to switch between a first configuration in which the electronic test signal generator is coupled to the transmitter and associated circuitry and a second configuration in which the data signal circuitry is connected to the transmitter and associated circuitry30. The unit of any preceding claim, wherein the at least one operational parameter comprises a property of a bias current provided to the transmitter, a property of a signal conditioning circuitry, a property of a drive signal,31. The unit of any preceding claim, wherein the first and / or second module comprises signal conditioning circuitry comprising at least one controllable component that changes a characteristic of the OWC channel, optionally wherein the controllable component comprises at least one or more of a filter, attenuator, amplifier, balun, logarithmic amplifier, splitter, switch, transmitter bias adjustment circuit.

32. The unit of claim 31, wherein the other module comprises at least one measurement device or sensor for measuring or sensing the at least one property of the OWC channel, optionally, wherein the measurement or sensing device comprises an ADC and sampling circuitry, a peak detector or, for example, an RMS detector.

34. The unit of any preceding claim, wherein the first and / or second module comprises temperature compensation circuitry configured to adjust the one or moreoperational parameters based on a detected temperature, optionally a temperature of the first and / or second module and / or an ambient temperature.

35. The status detection unit of claim X, wherein the first communication module comprises a first digital data interface and the second communication module comprises a second digital data interface: the first digital data interface and the second digital data interface each comprise one or more of an ethernet interface, a USB interface or a PCle interface, an HDM1 interface, an InfiniBand interface, a Thunderbolt cable interface, a channels for end points interface, a CAN bus interface, an SP1 interface, an SD10 interface, a UART interface, a JESD204B interface, a PON interface and / or a secondary access point interface; or the first digital data interface and the second digital data interface each comprise at least one USB-C gigabit ethernet interface; or the first digital data interface comprises a 24V DC jack and has an input between 50W and 100W, and the second digital data interface has an input between 5W and 30W.

36. A wireless communication system comprising: the status detection unit of any preceding claim; the first communication module of any preceding claim; and the second communication module of any preceding claim.

37. A method of detecting the status of a wireless communication system using the status detection unit of any preceding claim, the method comprising: determining the operational status of the wireless communication system using the status detection unit.

38. A method of calibrating a wireless communication system and / or an OWC channel of the system and / or one or more operational parameters of the system, the method comprising:determining the operational status of the system and / or determining one or more operating parameters for a first and / or second module based on the operational status of the system and / or determining one or more characteristics of an OWC channel, optionally wherein the method comprises transmitting an optical signal from one of the first and second communication module to the other of the first and second module using the OWC communication channel, wherein the transmitted optical signal is dependent on one or more operational parameters and measuring or sensing a property of the received optical signal and / or a signal derived from the received optical signal at the other of the first and second modules; selecting and / or adjusting the one or more operational parameters based on the measured or sensed property.

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