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Title:
OPTICAL WIRELESS COMMUNICATION DEVICE AND METHOD
Document Type and Number:
WIPO Patent Application WO/2019/106341
Kind Code:
A1
Abstract:
A portable lighting unit comprises at least one illumination light source configured to emit visible light illumination; a router; and at least one wireless communications access point (AP), the at least one AP comprising at least one optical wireless communications (OWC) transmitter; wherein the router is configured to receive first data from a first network and to transmit the first data to a second network via the at least one AP, the transmission of the first data via the at least one AP comprising controlling by the at least one OWC transmitter the operation of the at least one illumination light source to produce modulated light comprising or representative of the first data.

Inventors:
CSAJAGHY ISTVAN PHILLIPE BERNARD (GB)
AFGANI MOSTAFA ZAMAN (GB)
Application Number:
PCT/GB2018/053369
Publication Date:
June 06, 2019
Filing Date:
November 21, 2018
Export Citation:
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Assignee:
PURELIFI LTD (GB)
International Classes:
H04B10/114; H04B10/116; H04L12/64
Domestic Patent References:
WO2011000090A12011-01-06
Foreign References:
US9386668B22016-07-05
CN204739462U2015-11-04
JP3199295U2015-08-13
US20120027409A12012-02-02
US8503886B12013-08-06
US20110087879A12011-04-14
CN202813015U2013-03-20
Other References:
None
Attorney, Agent or Firm:
MARKS & CLERK LLP (GB)
Download PDF:
Claims:
CLAIMS:

1. A portable lighting unit comprising:

at least one illumination light source configured to emit visible light illumination; a router; and

at least one wireless communications access point (AP), the at least one AP comprising at least one optical wireless communications (OWC) transmitter;

wherein the router is configured to receive first data from a first network and to transmit the first data to a second network via the at least one AP,

the transmission of the first data via the at least one AP comprising controlling by the at least one OWC transmitter the operation of the at least one illumination light source to produce modulated light comprising or representative of the first data.

2. A portable lighting unit according to Claim 1 , wherein:

the portable lighting unit further comprises at least one photodetector;

the at least one AP further comprises at least one OWC receiver; and the router is further configured to receive second data from the second network via the at least one AP and to transmit the second data to the first network,

the receiving of the second data via the at least one AP comprising receiving modulated light by the at least one photodetector, and processing signals representative of the received modulated light by the at least one OWC receiver to obtain the second data.

3. A portable lighting unit according to Claim 1 or Claim 2, comprising a base portion, a lighting portion and a neck portion connecting the lighting portion to the base portion, wherein the router is located in the base portion and the at least one illumination light source is located in the lighting portion.

4. A portable lighting unit according to Claim 3, wherein the OWC transmitter and/or OWC receiver is located in the lighting portion.

5. A portable lighting unit according to Claim 3 or Claim 4, wherein the neck portion is at least partly flexible and is configured for a user to adjust a position and/or orientation of the lighting portion relative to the base portion, thereby adjusting a direction and/or coverage area of the visible light emitted by the at least one illumination light source.

6. A portable lighting unit according to any preceding claim, wherein the portable lighting unit comprises a desk lamp or table lamp.

7. A portable lighting unit according to any preceding claim, further comprising at least one further light source, wherein the OWC transmitter or a further OWC transmitter is configured to control the operation of the at least one further light source to produce modulated light.

8. A portable lighting unit according to Claim 7, wherein the at least one further light source is configured to emit infrared light.

9. A portable lighting unit according to any preceding claim, wherein:

the portable lighting unit further comprises at least one antenna; and

the at least one AP further comprises at least one non-optical wireless transmitter and/or at least one non-optical wireless receiver.

10. A portable lighting unit according to Claim 9, wherein the router is configured to receive third data from the first network and transmit the third data to the second network via the at least one AP, the transmission of the third data via the at least one AP comprising controlling by the at least one non-optical wireless transmitter the operation of the at least one antenna to produce radiation that is representative of the third data.

11. A portable lighting unit according to Claim 9 or Claim 10, wherein the router is configured to receive fourth data from the second network via the at least one AP and transmit the fourth data to the first network, the receiving of the fourth data via the at least one AP comprising receiving by the at least one photodetector radiation comprising or representative of the fourth data, and processing by the at least one non- optical wireless transmitter signals representative of the received radiation to obtain the fourth data.

12. A portable lighting unit according to any of Claims 9 to 11 , wherein the transmitted and/or received radiation comprises at least one of microwave radiation, radio-frequency radiation.

13. A portable lighting unit according to any of Claims 9 to 12 wherein the non- optical wireless transmitter and/or receiver comprises a Wi-Fi transmitter and/or receiver.

14. A portable lighting unit according to any preceding claim, wherein:

the portable lighting unit further comprises at least one wired interface; and the router is further configured to transmit data to and/or receive data from the second network via the at least one wired interface.

15. A portable lighting unit according to Claim 14, wherein the at least one wired interface is configured to transmit data to and/or receive data from at least one wired networking device, the at least one wired networking device comprising at least one of a network switch, an Ethernet switch, an Ethernet hub, a MAC bridge.

16. A network interface device comprising:

a router;

at least one wireless communications access point (AP), the at least one wireless communications access point comprising at least one optical wireless communications (OWC) transmitter and/or receiver and at least one non-optical wireless transmitter and/or receiver;

at least one light source and/or at least one photodetector; and

at least one antenna;

wherein at least one of a) and b)>

a) the router is configured to receive fifth data from a first network and to transmit the fifth data to the second network via the at least one AP, wherein the router is configured to determine whether the fifth data is transmitted using the at least one OWC transmitter and/or the at least one non-optical wireless transmitter;

b) the router is configured to receive sixth data from the second network via the at least one AP and to transmit the sixth data to the first network, wherein the router is configured to determine whether the sixth data is received using the at least one OWC receiver and/or the at least one non-optical wireless receiver.

17. A network interface device according to Claim 16, the network interface device comprising a housing, wherein the router, the at least one access point, the OWC transmitter and/or receiver, and the non-optical wireless transmitter and/or receiver are all provided within the housing.

18. A network interface device according to Claim 16 or Claim 17, wherein the router is configured to transmit the same data via the OWC transmitter as is transmitted via the non-optical wireless transmitter and/or wherein the router is configured to receive the same data via the OWC receiver as is received via the non-optical wireless receiver.

19. A network interface device according to any of Claims 16 to 18, wherein the router is configured to transmit different data via the OWC transmitter as is transmitted via the non-optical wireless transmitter and/or wherein the router is configured to receive different data via the OWC receiver as is received via the non-optical wireless receiver.

20. A network interface device according to any of Claims 16 to 19, further comprising at least one wired interface; wherein the router is further configured to determine whether the fifth data is transmitted using the at least one wired interface and/or whether the sixth data is received using the at least one wired interface.

21. A network interface device according to Claim 20, wherein the at least one wired interface is configured to transmit data to and/or receive data from at least one wired networking device, the at least one wired networking device comprising at least one of a network switch, an Ethernet switch, an Ethernet hub, a MAC bridge.

22. A network interface device according to any of Claims 16 to 21 , wherein the non-optical wireless transmitter and/or receiver forms part of a first chipset and the OWC transmitter and/or receiver forms part of a second chipset.

23. A network interface device according to any of Claims 16 to 21 , wherein the non-optical wireless transmitter and/or receiver and OWC transmitter and/or receiver form part of a common chipset.

24. A network interface device according to Claim 23, the common chipset comprising a baseband chip comprising a media access control (MAC) layer configured to receive data from the first network, a first physical (PHY) layer and a second physical (PHY) layer;

wherein the first PHY layer is configured to receive first data from the MAC layer and provide a first signal to the at least one light source, so as to drive the at least one light source to emit modulated light that comprises or is representative of the first data; and

the second PHY layer is configured to receive second data from the MAC layer and provide a second signal to the at least one antenna, so as to drive the at least one antenna to emit radiation that is representative of the second data.

25. A network interface device according to Claim 23, the common chipset comprising a baseband chip comprising a MAC layer configured to receive data from the first network and a PHY layer configured to receive data from the MAC layer and provide signals to at least one light source and to at least one antenna.

26. A network interface device according to Claim 24 or Claim 25, wherein the radiation comprises at least one of microwave radiation, radio-frequency radiation.

27. A network interface device according to any of Claims 16 to 26, wherein the at least one antenna comprises a plurality of antennas.

28. A network interface device according to Claim 27, wherein the antennas are arranged so as to provide substantially omnidirectional coverage.

29. A network interface device according to Claim 27 or Claim 28, wherein the at least one light source is provided in a first portion of the luminaire device and the plurality of antennas are provided in a second, different portion of the luminaire device.

30. A network interface device according to any of Claims 27 to 29, wherein the plurality of antennas are positioned so as to surround the at least one light source.

31. A network interface device according to any of Claims 16 to 30, wherein the network interface device is portable.

32. A network interface device according to any of Claims 16 to 30, wherein the network interface device is configured to be ceiling-mounted.

33. A portable lighting unit or network interface device according to any preceding claim, wherein the first network comprises a wide area network.

34. A portable lighting unit or network interface device according to any preceding claim, wherein the second network comprises at least one local area network or personal area network.

35. A portable lighting unit or network interface device according to any preceding claim, further comprising a modem, wherein the modem is configured to demodulate data received from the first network and/or modulate data to be transmitted to the first network, and wherein the router is configured to receive data from and/or transmit data to the first network via the modem.

36. A portable lighting unit or network interface device according to any preceding claim, wherein the portable lighting unit or network interface device configured to receive data from the first network via an optical input, wherein the optical input is configured to receive data sent via an optical wireless communication channel.

37. A portable lighting unit or network interface device according to any preceding claim, wherein the portable lighting unit or network interface device is configured to receive data from the first network via a wired connection.

38. A portable lighting unit or network interface device according to Claim 37, wherein the wired connection comprises at least one of coaxial cable, DSL, Ethernet, optical fibre.

39. A portable lighting unit or network interface device according to any preceding claim, wherein the data received from the first network conforms to a Data Over Cable Service Interface Specification (DOCSIS) standard.

40. A portable lighting unit or network interface device according to any preceding claim, configured to receive data from the first network via a high-capacity data input, wherein the at least one AP is configured to transmit the data received from the high- capacity data input substantially without a reduction in data rate.

41. A portable lighting unit or network interface device according to Claim 40, the portable lighting unit or network interface device comprising at least one of a high speed bus, a high-speed interconnect, a PCI express bus.

42. A portable lighting unit or network interface device according to any preceding claim, wherein the portable lighting unit or network interface device is configured to receive from the first network data having a data rate greater than 100 Mbit/s, optionally greater than 1 Gbit/s, further optionally greater than 10 Gbit/s.

43. A portable lighting unit or network interface device according to any preceding claim, wherein the at least one AP is configured to output data having a data rate greater than 100 Mbit/s, optionally greater than 1 Gbit/s, further optionally greater than 10 Gbit/s.

44. A system comprising a portable lighting unit or network interface device according to any preceding claim and at least one lamp unit, the or each lamp unit comprising a respective OWC receiver;

wherein the portable lighting unit or network interface device is configured to receive data from the first network and to transmit signals comprising or representative of the data to the or each lamp unit by transmission of modulated light from the at least one illumination light source, at least one light source and/or at least one further light source, the modulated light being received by the or each OWC receiver.

45. A system according to Claim 44, wherein the or each lamp unit further comprises a respective OWC transmitter configured to transmit data to the portable lighting unit or network interface device by modulation of light emitted by the or each lamp unit.

46. A system according to Claim 44 or Claim 45, wherein the or each lamp unit is configured to be ceiling-mounted.

47. A system according to any to Claims 44 to 46, wherein the at least one lamp unit comprises a plurality of lamp units, and the plurality of lamp units in combination with the portable lighting unit or network interface device form a local network.

48. A system according to any of Claims 44 to 47, wherein the at least one lamp unit is configured to transmit the data to at least one further lamp unit using optical wireless communication.

49. A system according to any of Claims 44 to 48, wherein at least one lamp unit is configured to transmit the data to at least one further device using power line communication.

50. A system according to Claim 49, wherein the power line communication comprises broadband over power line.

Description:
Optical Wireless Communication Device and Method

Field

The present invention relates to an optical wireless communication device and method, for example a network interface device configured to provide both optical and non- optical wireless communications.

Background

It is known to provide wireless data communications by using light instead of radio frequencies to transmit and receive data wirelessly between devices. Data may be transmitted using light by modulating at least one property of the light, for example an intensity of the light. Methods that use light to transmit data wirelessly may be referred to as optical wireless communications (OWC) or light communications (LC).

Different OWC protocols have different characteristics. For example, LiFi communication provides for high bandwidth, full-duplex communication using light, for example visible light or a combination of visible light and non-visible light, and can provide for the use of spectrum hopping and other spread spectrum techniques.

Wireless networks using visible light may in some circumstances allow a higher data capacity, greater energy efficiency and greater security than radio frequency wireless networks, and may also be used to replace point-to-point infrastructure in locations where conventional infrastructure does not exist or is too expensive to build.

OWC may provide communication using any suitable light source. For example, OWC may provide simultaneous wireless communication and illumination from luminaires (for example, LED luminaires) that have traditionally only been utilised for lighting or notification purposes. Thus, simultaneous optical wireless communication and illumination or other function may be provided. Optical wireless communication in such cases may be provided by modulating, for example, an intensity of the light produced by the luminaires so that data that is to be transmitted is represented by the modulation of the light. Usually the modulation of the light occurs at such a frequency that it is imperceptible to the naked eye. Optical wireless communication may normally provide line-of-sight, or reflected, communication between two compatible devices, each of which includes a light transmitter and/or receiver.

OWC, particularly LiFi using the visible light spectrum, is a fast-growing type of wireless communication technology. The visible light spectrum is 10,000 times larger than spectrum for radio waves. Therefore, the potential for wireless communication with visible light is great. With an ever-increasing demand for wireless data transmission, LiFi may be used for high speed data transfers. LiFi is rapidly progressing, and speeds of 10 Gbit/s or more may be achieved in a near future. Many companies are looking at the technology and predict data rates of 100s of Gbit/s in a foreseeable future.

OWC is also renowned for being a more secure wireless communication technology, since in general it does not travel through walls. The RF signals of Wi-Fi may travel through walls, leaking into neighbouring rooms, buildings or public spaces. Signals in the light spectrum, in contrast, may only be only accessible to users within the room or field of view of a given OWC access point. OWC may be a preferred option where data protection is desirable.

Summary

In a first aspect, there is provided a portable lighting unit comprising: at least one illumination light source configured to emit visible light illumination; a router; and at least one wireless communications access point (AP), the at least one AP comprising at least one optical wireless communications (OWC) transmitter; wherein the router is configured to receive first data from a first network and to transmit the first data to a second network via the at least one AP, the transmission of the first data via the at least one AP comprising controlling by the at least one OWC transmitter the operation of the at least one illumination light source to produce modulated light comprising or representative of the first data.

Providing a router and an access point comprising an OWC transmitter in a portable lighting unit may facilitate the use of OWC in a home, office or other environment. One or more light sources may provide both illumination and optical communication. The use of OWC may provide increased security when compared with, for example, Wi-Fi.

The portable lighting unit may further comprise at least one photodetector. The at least one AP may further comprise at least one OWC receiver. The router may be further configured to receive second data from the second network via the at least one AP and to transmit the second data to the first network. The receiving of the second data via the at least one AP may comprise receiving modulated light by the at least one photodetector, and processing signals representative of the received modulated light by the at least one OWC receiver to obtain the second data.

The at least one light source may comprise at least one of a light-emitting diode (LED), a laser, a VCSEL (vertical-cavity surface-emitting laser), a VCSEL array, a laser diode, or an LEP (light-emitting plasma).

The modulated light may be modulated at a modulation rate of at least 1 kHz, optionally at least 100 kHz, further optionally at least 1 MHz. The modulated light may be modulated at a modulation rate of less than 1 PHz, further optionally less than 1 THz, further optionally less than 100 GHz, further optionally less than 10 GHz.

The modulated light may be modulated with a modulation scheme comprising at least one of on-off keying (OOK), phase shift keying (PSK), M-ary pulse amplitude modulation (M-PAM), M-ary quadrature amplitude modulation (M-QAM) or orthogonal frequency division multiplexing (OFDM), 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), discrete multi-tone (DMT). The modulation may be coherent or incoherent.

The portable lighting unit may further comprise a base portion, a lighting portion and a neck portion connecting the lighting portion to the base portion. The router may be located in the base portion. The router may be located in the neck portion. The router may be located in the lighting portion. The at least one illumination light source may be located in the lighting portion. The OWC transmitter and/or OWC receiver may be located in the lighting portion. The neck portion may be at least partly flexible. The neck portion may be configured for a user to adjust a position and/or orientation of the lighting portion relative to the base portion, thereby adjusting a direction and/or coverage area of the visible light emitted by the at least one illumination light source.

The portable lighting unit may comprise a desk lamp or table lamp.

A user may choose to position a portable lighting unit (for example, a desk lamp or table lamp) close to the user in order to provide illumination, for example illumination of a desk or table. The positioning of the portable lighting unit close to the user may provide an improved OWC connection.

The portable lighting unit may further comprise at least one further light source. The OWC transmitter or a further OWC transmitter may be configured to control the operation of the at least one further light source to produce modulated light.

The at least one further light source may be configured to emit infrared light.

The portable lighting unit may further comprise at least one antenna.

The at least one AP may further comprise at least one non-optical wireless transmitter and/or at least one non-optical wireless receiver.

The router may be configured to receive third data from the first network and transmit the third data to the second network via the at least one AP, the transmission of the third data via the at least one AP comprising controlling by the at least one non-optical wireless transmitter the operation of the at least one antenna to produce radiation that is representative of the third data.

The router may be configured to receive fourth data from the second network via the at least one AP and transmit the fourth data to the first network, the receiving of the fourth data via the at least one AP comprising receiving by the at least one photodetector radiation comprising or representative of the fourth data, and processing by the at least one non-optical wireless transmitter signals representative of the received radiation to obtain the fourth data. By providing OWC and non-optical communication in a single portable lighting unit may provide increased functionality and/or flexibility.

By providing OWC and Wi-Fi communication through a single device, increased functionality may be provided to a user. The user may have more flexibility in the type of communication used. A conventional Wi-Fi router device may be replaced with a device that provides OWC communication, for example LiFi communication. Providing Wi-Fi and OWC communications on a single device may provide backward compatibility with Wi-Fi devices.

The transmitted and/or received radiation may comprise at least one of microwave radiation, radio-frequency radiation.

The non-optical wireless transmitter and/or receiver may comprise a Wi-Fi transmitter and/or receiver.

The portable lighting unit may further comprise at least one wired interface. The router may be further configured to transmit data to and/or receive data from the second network via the at least one wired interface.

The at least one wired interface may be configured to transmit data to and/or receive data from at least one wired networking device. The at least one wired networking device may comprise at least one of a network switch, an Ethernet switch, an Ethernet hub, a MAC bridge.

In a further aspect, which may be provided independently, there is provided a network interface device comprising: a router; at least one wireless communications access point (AP), the at least one wireless communications access point comprising at least one optical wireless communications (OWC) transmitter and/or receiver and at least one non-optical wireless transmitter and/or receiver; at least one light source and/or at least one photodetector; and at least one antenna. The router may be configured to receive fifth data from a first network and to transmit the fifth data to the second network via the at least one AP. The router may be configured to determine whether the fifth data is transmitted using the at least one OWC transmitter and/or the at least one non-optical wireless transmitter. The router may be configured to receive sixth data from the second network via the at least one AP and to transmit the sixth data to the first network. The router may be configured to determine whether the sixth data is received using the at least one OWC receiver and/or the at least one non-optical wireless receiver.

The network interface device may comprise a housing, wherein the router, the at least one access point, the OWC transmitter and/or receiver, and the non-optical wireless transmitter and/or receiver are all provided within the housing.

A single integrated unit may be provided which has both optical and non-optical wireless communication capabilities.

The router may be configured to transmit the same data via the OWC transmitter as is transmitted via the non-optical wireless transmitter. The router may be configured to receive the same data via the OWC receiver as is received via the non-optical wireless receiver.

The router may be configured to transmit different data via the OWC transmitter as is transmitted via the non-optical wireless transmitter. The router may be configured to receive different data via the OWC receiver as is received via the non-optical wireless receiver.

Light transmitted by the at least one light source and/or received by the at least one photodetector may comprise visible light and/or non-visible light. For example, light may comprise visible light, infra-red light or ultra-violet light. Optionally, the light may comprise electromagnetic waves with wavelengths in a range 1 nm to 1 mm, optionally in a range 1 nm to 2500 nm, which includes ultraviolet, visible light and near-infra-red wavelengths.

The at least one light source may comprise at least one of a light-emitting diode (LED), a laser, a VCSEL (vertical-cavity surface-emitting laser), a VCSEL array, a laser diode, or an LEP (light-emitting plasma). The network interface device may further comprise at least one wired interface. The router may be further configured to determine whether the fifth data is transmitted using the at least one wired interface. The router may be further configured to determine whether the sixth data is received using the at least one wired interface.

The at least one wired interface may be configured to transmit data to and/or receive data from at least one wired networking device. The at least one wired networking device may comprise at least one of a network switch, an Ethernet switch, an Ethernet hub, a MAC bridge.

The non-optical wireless transmitter and/or receiver may form part of a first chipset. The OWC transmitter and/or receiver may form part of a second chipset.

The non-optical wireless transmitter and/or receiver and OWC transmitter and/or receiver may form part of a common chipset. In some circumstances, the common chipset may be more efficient and/or less complex than separate chipsets.

The common chipset may comprise a baseband chip comprising a media access control (MAC) layer configured to receive data from the first network, a first physical (PHY) layer and a second physical (PHY) layer. The first PHY layer may be configured to receive first data from the MAC layer and provide a first signal to the at least one light source, so as to drive the at least one light source to emit modulated light that comprises or is representative of the first data. The second PHY layer may be configured to receive second data from the MAC layer and provide a second signal to the at least one antenna, so as to drive the at least one antenna to emit radiation that is representative of the second data.

Providing the single MAC layer and two PHY layers on a single chip may be lower cost and/or lower complexity than a design in which multiple chips are used, for example two chips each with a respective MAC layer and PHY layer. A single MAC layer may be more efficient and/or cost-effective than a plurality of MAC layers.

The common chipset may comprise a baseband chip comprising a MAC layer configured to receive data from the first network and a PHY layer configured to receive data from the MAC layer and provide signals to at least one light source and to at least one antenna.

The radiation may comprise at least one of microwave radiation, radio-frequency radiation.

The at least one antenna may comprise a plurality of antennas. The antennas may be arranged so as to provide substantially omnidirectional coverage. The at least one light source may be provided in a first portion of the luminaire device. The plurality of antennas may be provided in a second, different portion of the luminaire device. The plurality of antennas may be positioned so as to surround the at least one light source.

The network interface device may be portable.

The network interface device may be configured to be ceiling-mounted.

The first network may comprises a wide area network. The second network comprises at least one local area network or personal area network.

The portable lighting unit or network interface device may further comprise a modem. The modem may be configured to demodulate data received from the first network and/or modulate data to be transmitted to the first network. The router may be configured to receive data from and/or transmit data to the first network via the modem.

The portable lighting unit or network interface device may be configured to receive data from the first network via an optical input. The optical input may be configured to receive data sent via an optical wireless communication channel.

The portable lighting unit or network interface device may be configured to receive data from the first network via a wired connection.

The wired connection may comprise at least one of coaxial cable, DSL, Ethernet, optical fibre. The data received from the first network may conform to a Data Over Cable Service Interface Specification (DOCSIS) standard. The portable lighting unit or network interface device may be configured to receive data from the first network via a high-capacity data input. The at least one AP may be configured to transmit the data received from the high-capacity data input substantially without a reduction in data rate.

The portable lighting unit or network interface device may comprise at least one of a high-speed bus, a high-speed interconnect, a PCI express bus.

The portable lighting unit or network interface device may be configured to receive from the first network data having a data rate greater than 100 Mbit/s, optionally greater than 1 Gbit/s, further optionally greater than 10 Gbit/s.

The at least one AP may be configured to output data having a data rate greater than 100 Mbit/s, optionally greater than 1 Gbit/s, further optionally greater than 10 Gbit/s.

There may be provided a system comprising a portable lighting unit or network interface device according to any preceding claim and at least one lamp unit, the or each lamp unit comprising a respective OWC receiver. The portable lighting unit or network interface device may be configured to receive data from the first network and to transmit signals comprising or representative of the data to the or each lamp unit by transmission of modulated light from the at least one illumination light source, at least one light source and/or at least one further light source, the modulated light being received by the or each OWC receiver.

The or each lamp unit may further comprise a respective OWC transmitter configured to transmit data to the portable lighting unit or network interface device by modulation of light emitted by the or each lamp unit.

The or each lamp unit may be configured to be ceiling-mounted.

The at least one lamp unit may comprise a plurality of lamp units. The plurality of lamp units in combination with the portable lighting unit or network interface device may form a local network.

The at least one lamp unit may be configured to transmit the data to at least one further lamp unit using optical wireless communication. The at least one lamp unit may be configured to transmit the data to at least one further device using power line communication. The power line communication may comprise broadband over power line.

There may also be provided an apparatus or method substantially as described herein with reference to the accompanying drawings.

Features in one aspect may be applied as features in any other aspect, in any appropriate combination. For example, device features may be provided as method features or vice versa.

Brief description of the drawings

Various embodiments will now be described by way of example only, and with reference to the accompanying drawings, in which:

Figure 1 is a schematic diagram of a transmitter and receiver using optical wireless communication;

Figure 2 is a schematic diagram of a network interface device in accordance with an embodiment;

Figure 3a is a schematic diagram of components of a network interface device in accordance with an embodiment;

Figure 3b is the schematic diagram of Figure 3b, additionally showing high-speed connections;

Figure 4 is a schematic illustration of a home router luminaire in accordance with an embodiment

Figures 5a, 5b, 5c and 5d are schematic illustrations of exemplary arrangements of a light source and a plurality of antennas in a home router luminaire;

Figure 6 is a schematic diagram of OSI layers of a network interface device in accordance with an embodiment; and

Figure 7 is a schematic illustration of a local area network in accordance with an embodiment.

Detailed description 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.

Figure 1 is a schematic block diagram illustrating principles of optical wireless communication according to embodiments. Figure 1 shows a transmitter apparatus 1 and a receiver apparatus 4. The transmitter apparatus 1 is configured to send wireless optical signals in which information is encoded through an optical communication channel 2 to the receiver apparatus 4. The optical wireless communication channel 2 may be a free-space communication channel. The optical communications channel 2 has a characteristic optical wavelength. The optical communications channel 2 may also have a characteristic range of wavelengths. The optical communications channel 2 may also have a characteristic phase and/or polarisation.

Free space communication channels include transmission of optical signals through air, space, vacuum or similar. Free space communication does not include using solids to communicate, for example, optical fibre cables.

Transmitters and receivers may be provided on different devices. One type of device that is used may be referred to as an access point. Access points may provide access to a local network. Another type of device may be referred to as a station. Stations may be mobile or fixed. Without limitation, examples of stations include personal computers, desktops, laptops and smart devices.

The transmitter apparatus 1 includes a light emitting diode (LED), or other suitable light source, and an associated driving circuit to drive the LED to produce the optical signal. The associated driving circuitry includes a digital to analogue convertor configured to provide a modulation signal at a frequency characteristic of an optical light communication signal. A further processor, provided as part of the transmitter apparatus or associated with the transmitter apparatus, modulates data onto a drive current and the driving circuitry provides the drive current to the LED. The LED then produces an outgoing modulated optical wireless communication signal that carries the data. The receiver apparatus 4 includes a photodiode, or other suitable light detector, with associated circuitry to condition any received signal. The photodiode converts received light to an electronic signal which is then conditioned by the conditioning circuitry. Conditioning may include one or more filter steps; amplification of a weak electrical signal; equalisation of received signals and converting the analogue signals into digital signals using an analogue to digital convertor. The digital signals can then be provided to a further processor, provided as part of the receiver apparatus or associated with the receiver apparatus, to be demodulated to extract communication data.

Any suitable modulation scheme may be used, for example orthogonal frequency division multiplexing (OFDM) modulation schemes are used in some embodiments, and the demodulation is a demodulation 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), orthogonal frequency division multiplexing (OFDM), 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).

An access point may provide data transmission to and/or from a Wi-Fi or other non- optical wireless network and/or an optical wireless communications network, optionally a LiFi network.

The communication channel 2 provides a data stream between the transmitter apparatus 1 and the receiver apparatus 4. More than one free space communication channel of different wavelengths can be set up between the transmitter and the receiver (or, in other embodiments, multiple transmitters and/or receivers). This may lead to increased data transfer or bandwidth or increased flexibility in selecting which data stream to receive. More than one free space communication channel can be achieved, for example, by providing more than one light source as part of the transmitter apparatus.

Figure 2 is a schematic diagram illustrating a network interface device 10. The network interface device 10 is configured to combine modem and router technology with OWC technology, for example LiFi technology. The network interface device 10 may comprise or form part of a home luminaire, for example a desk lamp, table lamp, or overhead lamp. We note that although reference is made throughout this description of use of the network interface device 10 in a home, the network interface device 10 may also be used in an office or any suitable building or location.

The network interface device 10 comprises a modem 11 ; a router 12; an access point 14 comprising an optical wireless transceiver 16 and a non-optical wireless transceiver 18; an antenna 20; a photodetector 22; a light source 24; and a wired interface 26.

The modem 11 is a hardware component that is configured to receive data from a wide area network (WAN), and the router 12 is a hardware component that is configured to route data to further devices in at least one local area network (LAN) or personal area network (PAN) using the access point 14 and/or the wired interface 26.

In the present embodiment, the modem 11 is configured to modulate and demodulate data in accordance with the modulation scheme or schemes that are in use. In some embodiments, a separate modem device is provided which is external to the network interface device 10. In such embodiments, the network interface device 10 may not itself comprise a modem.

The access point 14 is a wireless interface that is configured to receive data from the router 12 and to transmit the data to the further devices using the optical wireless transceiver 16 and/or non-optical wireless transceiver 18. In this description, the term access point is used to refer to a wireless interface, whether the interface is optical and/or non-optical. The terms access point and wireless interface may be used interchangeably.

In the embodiment of Figure 2, the access point 14 comprises one optical wireless transceiver 16 and one non-optical wireless transceiver 18. In other embodiments, the access point 14 may comprise any suitable number of optical and/or non-optical transmitters and/or receivers.

The optical wireless transceiver 16 is configured to transmit data received from the router 12 by modulation of light emitted by the light source 24. 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.

In the present embodiment, the light source 24 is an LED light source which is configured to emit visible light that is used both for illumination and for optical wireless communication. In other embodiments, any suitable light sources may be used, for example laser, laser diode, VCSEL (vertical cavity surface-emitting laser) or LEP (light- emitting plasma) light sources. The light source 24 may comprise a plurality of light sources, for example an array of light sources. The light source 24 has a first characteristic wavelength.

The light source 24 may be referred to as an illumination light source. In other embodiments, the light source 24 may comprise any modulateable light source, which may or may not be used for illumination. In some embodiments, a separate light source (not shown) is used for illumination and the light source 24 is used for optical wireless communication. In some such embodiments, the light source 24 may be configured to emit light that is not visible to the human eye, for example infrared light.

The optical wireless transceiver 16 is further configured to receive signals from the photodetector 22 that are representative of modulated light received by the photodetector 22, to process those signals to obtain data, and to pass that data via the router 12 to the modem 11 for transmission to the WAN. The photodetector is configured to detect light having a second characteristic wavelength. In the present embodiment, the photodetector 22 is a photodiode that is configured to detect infrared light. In other embodiments, any suitable type of photodetector may be used.

The non-optical wireless transceiver 18 is configured to transmit data received from the router 12 by a wireless transmission method that does not comprise optical wireless communication. In the present embodiment, the non-optical wireless transmission method is Wi-Fi. The non-optical wireless transceiver 18 is configured to transmit data received from the modem 11 via the router 12 using radio-frequency signals emitted by the antenna 20. The non-optical wireless transceiver 18 is configured to receive radio frequency signals via the antenna 20, to process the radio-frequency signals to obtain data, and to pass the data via the router 12 to the modem 11 for transmission to the WAN. In the embodiment of Figure 2, the network interface device 10 comprises a single access point 14 which comprises one optical wireless transceiver 16 and one non- optical wireless transceiver 18. In other embodiments, the network interface device 10 may comprise any number of access points, for example two or more access points. Each access point may comprise one or more optical and/or non-optical transmitters, receivers and/or transceivers. An access point may be configured to transmit and/or receive over multiple channels. For example, multiple light sources may be used to transmit and/or multiple photodetectors may be used to receive optical wireless communications. Multiple antennas may be used to transmit and/or receive non-optical wireless communications. In some embodiments, multiple light sources may be used to transmit over a single channel. In some embodiments, multiple photodetectors may be used to receive over a single channel. In some embodiments, multiple antennas may be used to transmit and/or receive over a single channel.

The wired interface 26 is configured to send data from the modem 11 via the router 12 to one or more wired networking devices (not shown), for example an Ethernet switch, Ethernet hub, network switch or MAC bridge. The one or more wired networking devices may then send the data to one or more further devices via a wired connection, for example an Ethernet connection.

In the description above, we have used the term network interface device to refer to the device as a whole. We use the term router to refer to the hardware component 12 that is used to direct data from a first network (which in this embodiment is a WAN) to further devices in a second network (which in this embodiment is a LAN). We use the term access point to refer to a wireless interface, whether the wireless interface is optical and/or non-optical. However, we note that the network interface device 10 as a whole may sometimes alternatively be referred to as a router, a wireless router, or an access point.

Figure 3a is a schematic diagram which illustrates certain hardware components of the network interface device 10 in greater detail. The network interface device 10 further comprises a WAN port 30 through which the modem 11 communicates with the WAN; a power supply 32 configured to supply power to the network interface device 10; the router 12 comprises a microprocessor 34 comprising an embedded host that performs the data routing; a random access memory (RAM) 36 and storage 38. The network interface device 10 may also comprise a firewall (not shown). The network interface device 10 further comprises a wired LAN port 40 configured to provide a wired connection between the wired interface 26 and one or more wired networking devices.

The network interface device 10 further comprises a Wi-Fi chipset 42 and an optical wireless communication chipset 44 (here shown as a LiFi chipset) which are configured to provide the functionality of the access point 14. In other embodiments, the functionality of the access point 14 may be provided by a single chipset which provides both Wi-Fi and LiFi capabilities. In some embodiments, the single chipset may also provide wired capabilities. The chipsets are described in more detail below with reference to Figure 6.

Figure 3b shows the same network interface device 10. Figure 3b also shows high speed connections 45, 46, 47, 48. Each of the high speed connections 45, 46, 47, 48 may comprise at least one of a high-speed bus, high-speed interconnect or PCI express bus. High speed connection 45 connects the modem 11 to the microprocessor 34. High speed connection 46 connects the microprocessor 34 to the wired LAN port 40. High speed connection 47 connects the microprocessor 34 to the Wi-Fi chipset 42. High speed connection 48 connects the microprocessor 34 to the LiFi chipset 44.

In the present embodiment, the various components described above with reference to Figures 2, 3a and 3b are provided within a single housing. Both Wi-Fi and LiFi capabilities are therefore provided within a single housing.

In use, the modem 11 receives data from the WAN via the WAN port 30. In the present embodiment, high-speed data is received at the WAN port 30 from a coaxial cable. The high-speed data is transmitted over the cable using the DOCSIS (Data Over Cable Service Interface Specification) standard. In other embodiments, the WAN port may receive data via any suitable connection, for example a cable connection, DSL connection or optical connection. The receiving of data from the WAN is discussed in more detail below with reference to Figure 7.

The router 12 directs data to the access point 14 and/or the wired interface 26. Data that is directed to the access point 14 is transmitted using the optical wireless transceiver 16 and the light source 24 and/or using the non-optical wireless transceiver 18 and the antenna 20. Data that is directed to the wired interface 26 is transmitted over a wired connection. Data may be transmitted to any one or more further device in the LAN, for example computing devices, mobile devices or LiFi enabled luminaires.

Further devices in the LAN may also send data to the network interface device 10. Some further devices may send data via modulated light which is received by the photodetector 22 and processed by the optical wireless transceiver 16. Some further devices may send data via radio-frequency radiation (for example, by Wi-Fi). The radiation is received by the antenna 20 and processed by the non-optical wireless transceiver 18. Some further devices may send data via a wired connection to the wired interface 26 via the LAN ports 40. Data received by the access point 14 or wired interface 26 is passed to the router 12. The router 12 then passes the data to modem 11 which passes the data to the WAN via the WAN port 30.

By providing OWC and Wi-Fi communication through a single device, increased functionality may be provided to a user. The user may have more flexibility in the type of communication used. A conventional Wi-Fi router device may be replaced with a device that provides OWC communication, for example LiFi communication. The use of OWC may provide increased security.

Providing Wi-Fi and OWC communications on a single device may provide backward compatibility with Wi-Fi devices. For example, providing Wi-Fi and LiFi on a single device may provide backward compatibility to devices that do not have LiFi enabled. Providing Wi-Fi and LiFi on a single device may provide a backup in case a LiFi connection fails.

In some circumstances, OWC capability may be retrofitted to existing devices that did not previously provide OWC capability. For example, OWC capability may be provided by a dongle or other detachable device which is coupled to a device, for example a computer or mobile device. Providing Wi-Fi and OWC functionality on a single network interface device may facilitate a transition period in which, for example, some devices have built-in OWC capability, some devices have retrofitted OWC capability, and further devices have no OWC capability. By using optical wireless communications (for example, LiFi) it may be the case that a wireless transmission method may be provided in which data rates for wireless transmission may match incoming data rates, for example incoming WAN data rates. Optical wireless communications, for example visible light communication, may provide a way to match the speed of incoming high-speed data, for example incoming DOCSIS data rates.

Wi-Fi may currently suffer from issues around network security. It may be difficult to stop an RF signal from travelling outside a secure space. It may therefore be possible to hijack an RF communication. Methods of protecting a network with passwords or other security levels may be worked around.

Security risks may include data interception. Wi-Fi RF signals may be intercepted by eavesdroppers within a few hundred feet or even farther with directional antennas. Encryption methods such as AES-CCMP data encryption may go some way to reduce this risk. In contrast, OWC may require an eavesdropper to be positioned at some point within a room or directly at a door or window where some reflection may occur.

Security risks may also include denial of service. OWC may have an available frequency spectrum that is over 10,000 times greater than the radio spectrum. The higher available spectrum may limit the chances of Denial of Service.

A network interface device 10 that provides both OWC and Wi-Fi functionality may be designed in such a way as to be less unsightly than some existing devices, for example existing Wi-Fi router devices. An example of such design is described below with reference to Figure 4, in which a network interface device 10 is integrated into a portable luminaire.

A home router luminaire may be a luminaire that at least partially incorporates a network interface device, for example a network interface device 10 as described above with reference to Figures 1 and 2. The home router luminaire provides OWC functionality, and may also provide Wi-Fi functionality.

A home router luminaire may be used instead of a standalone router that provides communication only. The home router luminaire provides illumination and optical wireless communication. Optionally, the home router luminaire may also provide non- optical wireless communication and/or wired communication.

At present, many home Wi-Fi router devices may be considered unsightly. Home router devices may be substantially square boxes that may usually be positioned such that they are out of view. Home router devices may be standalone devices with no other use than providing internet connection points. They usually are not very attractive, so people tend to hide them, potentially damaging the wireless signal quality, and therefore reducing the data rate furthermore.

Home sizes are shrinking, so people may prefer to have fewer possessions. A conventional home router device may be an electrical item that has not been chosen by the user but may instead have been chosen by an internet provider. For good Wi-Fi range, a router device may become bulky and ugly.

Wi-Fi extender devices exist. However, Wi-Fi extenders are additional devices which may increase energy consumption and/or may take up power sockets which are usually limited.

An example of a home router luminaire is illustrated schematically in Figure 4. The home router luminaire of Figure 4 is configured to provide both optical wireless communications and non-optical wireless communications. The home router luminaire device 60 takes the form of a small desktop lamp. The desktop lamp 60 provides directional light to a desk area. The desktop lamp 60 provides a fairly short LiFi connection from lamp to desk.

The desktop lamp 60 comprises a base portion 62, a neck portion 64, and a lighting portion 66. The neck portion 64 connects the lighting portion 66 to the base portion 62. The neck portion 64 is flexible to allow for repositioning of the lighting portion 66, for example changing a direction of illumination from the lighting portion 66.

The base portion 62 comprises a WAN port 30 configured to receive data from a WAN 68. The base portion 62 further comprises a modem 11 , a router 12 and a first access point 63 comprising a non-optical wireless transceiver 18. In the embodiment of Figure 6, the neck portion 64 further comprises an antenna 20. In other embodiments, each the WAN port 30, modem 11 , router 12 and non-optical wireless transceiver 18 may be positioned in any suitable part of the desktop lamp 60, for example in the base portion 62, neck portion 64 or lighting portion 66.

Figure 4 also shows a LiFi enabled device 70, which in this embodiment is a laptop. The home router luminaire 60 is configured to communicate with the laptop 70 using both Wi-Fi and LiFi communications. The laptop 70 comprises a further optical wireless transceiver, an infrared light source (for example, an LED), and a photodetector (for example, a photodiode) configured to receive visible light.

The home router luminaire device 60 is configured to provide Wi-Fi communication from the neck portion 64 to the laptop 70. The Wi-Fi connection between the neck portion 64 and laptop 70 is shown by arrow 80. The Wi-Fi connection between the neck portion 64 and laptop 70 may be described as a high speed wireless link.

The lighting portion 66 comprises at least one light source 24. In the embodiment of Figure 4, the at least one light source 24 comprises a plurality of LEDs. The LEDs provide visible light illumination. A direction of the visible light illumination may be changed by adjusting the position of the lighting portion 66 using the flexible neck portion 64. In the present embodiment, the LEDs that provide visible light illumination are also used to transmit data by modulation of the emitted visible light.

The lighting portion 66 comprises a second access point 65 which comprises an optical wireless transceiver 16. The optical wireless transceiver 16 is configured to receive data from the router 12 in the base portion 62 and to transmit data by modulating the light emitted by the plurality of LEDs. The lighting portion 66 further comprises at least one photodetector 22, which is configured to detect infrared light.

Wi-Fi and LiFi capabilities are therefore provided by different access points which are positioned in different parts of the home router luminaire 60. In other embodiments, Wi Fi and LiFi capabilities may be provided by a single access point. In further embodiments, any number of access points may be positioned in any suitable locations within the home router luminaire 60. Arrow 82 is representative of the LiFi downlink connection by which data is transmitted from the optical wireless transceiver 16 to the laptop 70 by modulated visible light emitted from the plurality of LEDs. Visible light emitted by the LEDs is received by the further photodetector in the laptop 70, and signals representative of the received light are processed by the further optical wireless transceiver in the laptop 70.

Arrow 84 is representative of the LiFi uplink connection by which data is transmitted from the laptop 70 to the optical wireless transceiver 16 by emission of modulated infrared light by a light source of the laptop 70. Modulated infrared light from the further light source of the laptop 70 is received by the photodetector 22, and signals representative of the received modulated infrared light are processed by the optical wireless transceiver 16.

In other embodiments, the uplink and downlink connections between the optical wireless transceiver 16 and the laptop 70 may be provided using any suitable wavelengths of light, for example visible, infrared or ultraviolet light.

In the embodiment of Figure 4, the illumination provided by the plurality of LEDs is directional. The lighting portion 66 may be pointed towards an area of interest. The desk lamp 60 may be used both to illuminate an area, for example a work area, and to send data to a device positioned within that area, for example laptop 70.

In other embodiments, the home router luminaire 60 may take the form of a larger living room luminaire, for example a large freestanding lamp or an overhead light fitting. The living room luminaire may provide longer range LiFi than the desktop lamp 60. The living room luminaire may provide a wider coverage area than the desktop lamp 60 or other directional luminaires.

In the embodiment of Figure 4, an access point comprising an OWC transmitter and receiver is positioned in the lighting portion 66 of the desktop lamp 60. The light source and photodetector are positioned close to each other within the lighting portion 66. In some other embodiments, the light source and photodetector may be positioned in different positions, for example in different parts of the luminaire. For example, components may be positioned differently to take into account the positions of devices to which uplink and/or downlink connections are to be formed. In some embodiments, the light source and photodetector may be positioned so as to optimise field of view and line of sight. For example, light from the light source may be pointed down to a desk to connect to a laptop or portable device, or upwards to connect with access points, repeaters or a mesh network. An example of an upward- pointing connection is described below with reference to Figure 7.

In further embodiments, any of the components of the desktop lamp 60 may be positioned in any suitable part of the desktop lamp 60, for example in the base portion 62, neck portion 64 or lighting portion 66.

A home router luminaire (for example, a desktop lamp 60 as illustrated in Figure 4) may be designed such that it is a piece of design. A home router luminaire may be designed to provide both light and communication to a user. A luminaire may be likely to be placed near to a user (for example, such that it illuminates a user’s desk or living space). In some circumstances, a luminaire may be positioned nearer to a user than a standalone router device would be placed (for example, a standalone router device may often be positioned in a hallway). Being placed closer to a user may increase a quality of wireless communication (optical and/or non-optical) that is available to the user.

The luminaire may be made in any shapes and sizes, as long as it can embed all the circuitry required for the home router features and LiFi interface. This may allow designers to make attractive objects for the consumer, offering them the choice to suit their taste.

In some embodiments, Wi-Fi communication may be improved by providing more space in the router device for antennas. Conventional Wi-Fi router devices may be designed to minimise the size of the Wi-Fi router device. However, a user may be willing to accept a larger size for a luminaire than for a standalone router device. A home luminaire router device in accordance with some embodiments may provide longer Wi-Fi range than some conventional Wi-Fi routers. A home luminaire router device in accordance with some embodiments may provide better spatial distribution compared to some current square router devices, which may be quite directional. In some embodiments, a light source is provided in one portion of a luminaire and antennas are provided in a different portion. In other embodiments, antennas surround the light source.

Figures 5a to 5d are schematic illustrations of some exemplary arrangements of a light source 72 and a plurality of antennas 74 or 76. In Figure 5a, a plurality of conventional antennas 74 are provided below a light source in the base of a luminaire. The light source 72 and/or antennas 74 may be pivotable. In Figure 5b, a plurality of conventional antennas 74 are provided above a light source 72, for example in a shade of a luminaire. In Figure 5c, a plurality of omnidirectional biquad antennas 76 are positioned surrounding a neck portion of a luminaire. In Figure 5d, a plurality of omnidirectional biquad antennas 76 are positioned around a light source 72 of a ceiling-mounted luminaire.

We now turn to the implementation of the Wi-Fi and OWC capabilities of the network interface device or home router luminaire at the chip level. As described above, the network interface device 10 (or home router luminaire) comprises a Wi-Fi chipset 42 and an OWC chipset 44, which in the embodiment of Figure 2 is a LiFi chipset.

Figure 6 is a schematic diagram of the Open System Interconnection (OSI) protocol stack of the network interface device 10. Layer 3 (denoted by reference numeral 93) is the network (routing) layer, in which data is received from the modem 11 by the router 12. Layer 2 (denoted by reference numeral 92) is the data link layer. Layer 2 comprises a logical link layer 94 and MAC layer 95. Layer 1 (denoted by reference numeral 91) is the physical layer. A first physical link 96, which is provided by the non-optical wireless transceiver 18 and antenna 20, comprises 802.11a Wi-Fi. A second physical link 97, which is provided by the non-optical wireless transceiver 18 and antenna 20, comprises 802.11g Wi-Fi. A third physical link 98, which is provided by the non-optical wireless transceiver 18 and antenna 20, comprises 802.11ac Wi-Fi. A fourth physical link 99, which is provided by the optical transceiver 16, light source 24 and photodetector 22, comprises LiFi.

In some embodiments, a single chipset provides the functionality of the Wi-Fi chipset 42 and OWC chipset 44 that are illustrated in Figure 2. In some embodiments, the chipset comprises a MAC layer, a first PHY layer and a second PHY layer. The MAC layer may be referred to as a unified MAC layer. The MAC layer is configured to receive data from the WAN. The MAC layer is configured to process the data received from the network in accordance with at least one medium access protocol to create frames, and to pass the frames to the first and second PHY layers. The MAC layer may provide, for example, contention and channel sharing. The functionality of the MAC layer may be in accordance with, for example, IEEE 802.15.7, 802.15.13, 802.11 or extensions or developments thereof; ITU-T G.9960 or extension or developments thereof; or ITU-T G.vlc or extensions or developments thereof.

The first PHY layer and second PHY layer are each configured to process frames received by the MAC layer to generate PHY frames that are suitable by physical transmission. The processing of the frames received from the MAC layer may include, for example, modulation using a suitable modulation scheme, and adding a PHY header. The functionality of each PHY layer may be in accordance with, for example, IEEE 802.15.7, 802.15.13, 802.11 or extensions or developments thereof; or ITU-T G.9960 or extension or developments thereof; or ITU-T G.vlc or extensions or developments thereof.

Any suitable modulation scheme may be used by each of the PHY layers, for example without limitation on-off keying (OOK), phase shift keying (PSK), M-ary pulse amplitude modulation (M-PAM), M-ary quadrature amplitude modulation (M-QAM) or orthogonal frequency division multiplexing (OFDM), 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), discrete multi-tone (DMT). In some embodiments, the different PHY layers use the same modulation scheme. In other embodiments, different modulation schemes are used by the different PHY layers.

The first PHY layer outputs a first digital signal. The first digital signal comprises PHY frames in which first data is encoded. The first digital signal is transmitted by modulation of visible light from the light source.

The second PHY layer is configured to send a second digital signal using Wi-Fi. The second digital signal comprises PHY frames in which second data is encoded. The second digital signal is transmitted using radiation from the antenna. A single MAC layer therefore provides concurrent support for both optical transmission and radio-frequency transmission.

In some embodiments, a first PHY protocol is used by the first PHY layer to support transmission over a first medium. A second, different PHY protocol is used by the second PHY layer to support transmission over a second, different medium. In other embodiments, the single MAC layer and first and second PHY layers may provide concurrent support for any suitable media types, for example optical, copper or radio. For example, the first PHY layer may be configured to send signals over an optical connection and the second PHY layer may be configured to send a signal over a wired connection, for example a network connection which may be an Ethernet connection.

Although two PHY layers are described above, in further embodiments any suitable number of PHY layers may be supported by a single unified MAC layer. For example, three or four PHY layers may be supported by a single unified MAC layer. The three or four PHY layers may be used to produce three or four data streams.

In general, by using a single unified MAC layer in combination with two or more PHY layers, transmission to a mix of devices may be performed without the network layer having to know which devices the data is to be sent to, or what type of communication channel is to be used. This may be abstracted by the unified MAC layer. By using two or more PHY layers, different PHY protocols may be used. Different modulation schemes may be used by the different PHY layers. The different PHY layers may transmit over different transmission media.

In further embodiments, a single chip may comprise a single MAC layer and single PHY layer which are configured to support both Wi-Fi transmission and LiFi transmission.

Reference is made above to a home router luminaire, and to the use of devices in a home. Similar considerations may also apply to the use of a router device in businesses or other spaces. For example, a respective luminaire (for example, a desk lamp) may be placed near to each user in an office building. The luminaire may be equipped for LiFi communication and optionally also for Wi-Fi and/or wired communication.

At present, network routers may be found in every or almost every connected home, office and public building. Anyone who wishes to use an internet connection may use a network router. Conventional network routers usually provide internet access to users though Wi-Fi or Ethernet ports.

Broadband access may be provided to a customer via cable (over coaxial cable), DSL (digital subscriber line), fibre optic cable, or any other suitable method (for example, satellite broadband). Different methods may provide different data speeds. For example, satellite broadband may provide speeds up to 30 Mbit/s and fibre straight to premises may provide speeds up to around 100 Mbit/s.

For DSL, high speeds may be achieved using the latest standard VDSL2-Vplus (standard ITU G.993.2 Amendment 1), which was approved in November 2015. It promises to deliver speeds of up to 300 Mbit/s downstream and 100 Mbit/s upstream.

For coaxial cables, there is an international standard in place which is called DOCSIS (Data Over Cable Service Interface Specification). DOCSIS defines the achievable data rate between a user’s router and an internet provider’s modem.

DOCSIS 3.1 Full Duplex was announced in February 2016. DOCSIS 3.1 Full Duplex promises a real duplex 10 Gbit/s data rate from the network to the user’s router. It uses the full spectrum of the cable (0 MHz to 1.2 GHz) at the same time on the uplink and downlink.

In some existing systems, high data rates (for example, more than 1 Gbit/s) may arrive to a router, but there may not be any wireless communication method provided by the router that is capable of matching the speed of incoming data. At present, Wi-Fi may offer a best speed of around 1.3 Gbit/s using the latest 802.11ac standard. The limited available spectrum for radio waves may make it more and more difficult to increase Wi Fi speeds. In some circumstances, if faster data rates are desired, Ethernet cables (Cat-6 onwards) may be used instead of wireless transmission. The use of a network interface device having OWC capability may in some circumstances enable the provision of wireless communication with a data rate that matches that of incoming data. By using OWC instead of (for example) Wi-Fi, a cost effective method may be provided for a customer to maintain DOCSIS data rates all the way to a user’s device wirelessly.

Figure 7 is a schematic illustration of a local area network comprising a home router luminaire 100. The home router luminaire 100 comprises a base portion 102, neck portion 104 and lighting portion 106. The neck portion 104 of the home router luminaire 100 comprises a modem (not shown), a router (not shown) and a first access point comprising a non-optical wireless transceiver (not shown). The lighting portion 106 of the home router luminaire 100 comprises a second access point comprising an optical wireless transceiver (not shown).

The local area network of Figure 7 further comprises a plurality of overhead lamp units 110, 112, 114. Each of the overhead lamp units 110, 112, 114 comprises a respective optical wireless transceiver.

The lighting portion 106 of the home router luminaire 100 comprises at least one light source which is configured to emit light upwards towards at least one of the overhead lamps 110, 112, 114.

In the present embodiment, the modem in the neck portion 104 of the home router luminaire 100 receives data from an internet provider’s network 128 via a coaxial cable connection that operates using the DOCSIS standard. The connection to the internet provider’s network is illustrated by arrow 120 in Figure 7. In other embodiments, the data is received from the WAN via any suitable connection, for example an optical connection or DSL connection.

The optical wireless transceiver sends data to at least one of the overhead lamps 110, 112, 114 by modulation of light emitted by the at least one light source. The modulated light provides a LiFi connection which is illustrated by arrow 122 in Figure 7.

The LiFi connection illustrated by arrow 122 may be considered to provide a high speed link to the lamp units 110, 112, 114, which is illustrated by arrow 124. In the embodiment illustrated in Figure 7, the first overhead lamp unit 110 receives data from the home router luminaire device 100 by optical communication (arrow 122). The first overhead lamp unit 110 sends data to second and third overhead lamp units 112, 114 by optical wireless communication For example, the first overhead lamp unit 110 may communicate with the second overhead lamp unit 102 and/or the third overhead lamp unit 104 using infrared light.

Each of the overhead lamps units 110, 112, 114 may then transmit at least part of the data to further devices (not shown) using optical wireless communication. For example, different overhead lamp units may provide coverage for different parts of a room.

In a further embodiment, the overhead lamp units 110, 112, 114 are connected together by a wired data connection.

In some circumstances, a home luminaire router device in combination with overhead OWC-enabled lamp unit as illustrated in Figure 7 may be used instead of having a wired connection to each of the overhead OWC-enabled lamp units. The solution of Figure 7 may greatly reduce installation cost and disruption by enabling a high-speed OWC communication without the need for a long cable. Depending on the way the OWC network is set up, the cabling may be reduced to connections between light bulbs only or may be replaced using a point to point infrared link. The point to point infrared link may maintain a high-speed link with no cabling required for that infrared link.

Each of the overhead lamp unit 100, 102, 104 may comprise an enhanced light bulb which has a normal light bulb fitting. The network shown in Figure 7 may therefore by implemented in existing lighting installations.

Replacing Wi-Fi with a higher speed wireless link between the bulbs of the overhead lamps 100, 102, 104 may enable a high-speed VLC network with little or no disruption to an existing lighting installation.

Some existing LiFi installations may require a large amount of work on the lightning installation of new and existing buildings. For example, some existing LiFi installations may require a lot of cabling (for example, installing Ethernet cables to each LiFi- equipped lighting fixture). The installation of such LiFi systems may involve potentially costly and disruptive work. The work involved in installing a LiFi system may discourage most homeowners from installing LiFi technology, despite the potential advantages (for example, high speed and network security).

By using the system shown in Figure 7, an OWC network mesh may be provided with a local network of light bulbs in a room, without a long Ethernet cable from a router to the light bulbs.

In further embodiments, communication between the overhead lamp units 100, 102, 104 may be provided by using the light bulbs in the overhead lamp units 100, 102, 104 as Broadband over Power Line (BPL) modems. Broadband over Power Line may also be referred to as powerline communication (PLC). Certain types of powerline communication may be referred to as HomePlug. Powerline communication may be provided in accordance with the IEEE 1901 standard or extensions or developments thereof. At present, the IEEE 1901 standard is only allowing up to 500Mbit/s but this may increase over time.

In embodiments in which BPL is used to send data between the overhead lamp unit, one lamp unit may act as a translator of LiFi to BPL. A smart grid may then be available in a house or other premises.

The use of a router device or home router luminaire device as described above may enable a way to communicate with LiFi enabled light bulbs. It may eliminate a requirement for a long cable from a router to LiFi enabled light bulbs. It may create solutions to enable a high speed wireless network with very little change to an existing home (or office) installation.

In the embodiments described above, the network interface device 10 or luminaire 60 is used to provide both optical and non-optical wireless communication. In other embodiments, a network interface device 10, for example a home luminaire router device, may be used to provide optical wireless communication without providing non- optical wireless communication (for example, Wi-Fi). For example, the non-optical wireless transceiver 18 and antenna 20 may be omitted from the network interface device 10 of Figure 2. In some embodiments, a network interface device 10 may be used to provide optical wireless communication without providing a wired connection. For example, the wired connection 26 may be omitted from the network interface device 10 of Figure 2. In some embodiments, a network interface device or home router luminaire may have both optical wireless input and optical wireless output. For example, a network interface device may receive data from a computer by optical wireless communication. The network interface device may transmit that data to multiple further devices, for example LiFi-enabled lamp units as shown in Figure 7.

Although a network interface device comprising a modem and router is described above, in other embodiments an extender device may be provided that does not comprise a router. The extender device may retransmit data that is receives via a modem. The extender device may use any of the input or output methods that are described above with reference to the network interface device.

References to LiFi above may also refer to other types of optical wireless communication. A skilled person will appreciate that variations of the enclosed arrangement are possible without departing from the invention. Accordingly, the above description of the specific embodiment is made by way of example only and not for the purposes of limitations. It will be clear to the skilled person that minor modifications may be made without significant changes to the operation described.




 
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