WO2019110984A1

WO2019110984A1 - Optical communications access point

Info

Publication number: WO2019110984A1
Application number: PCT/GB2018/053516
Authority: WO
Inventors: Stefan VIDEV; Harald Haas
Original assignee: The University Court Of The University Of Edinburgh
Priority date: 2017-12-05
Filing date: 2018-12-04
Publication date: 2019-06-13
Also published as: GB201720274D0

Abstract

An apparatus (12) is connectable to a backbone for a network (10) comprising at least one other apparatus (12). The apparatus (12) comprises an optical communications access point or transceiver and is configured to receive optical communications signals and transmit optical communications signals. At least one of the received and transmitted optical communications signals is communicated via the at least one other apparatus (12) of the backbone.

Description

Optical Communications Access Point

Field

The present disclosure relates to an optical wireless acess point and associated network and method of operation. An example described herein relates to a transceiver architecture design for VLC (visual light communications) networking, but the present invention is not limited to this.

Background

In order to deliver a truly flexible and deployment friendly solution for optical wireless communications, the system architecture needs to support the desired networking functionality on the hardware level.

Summary

According to a first aspect of the present disclosure there is provided an apparatus connectable to a backbone for a network comprising at least one other apparatus. The apparatus may comprise an optical communications access point or transceiver. The apparatus may be configured to receive optical communications signals and transmit optical communications signals. At least one of the received and transmitted optical communications signals may be communicated via the at least one other apparatus of the backbone.

According to a second aspect of the present disclosure there is provided an optical communications access point or transceiver. The optical communication access point or transceiver may be configured to receive optical communications signals, e.g. from communications devices, mobile communications devices and/or other optical communication access points or transceivers. The optical communication access point or transceiver may be configured to transmit optical communications signals, e.g. to communications devices, mobile communications devices and/or other optical communication access points or transceivers.

The optical communications signals may be or comprise data signals. The optical communication access point or transceiver may be comprised in a network, e.g. with one or more other optical communication access points or transceivers. The optical communication access point or transceiver may be a backbone optical communication access point or tranceiver, e.g. it may receive and transmit at least some or all of a plurality of signals, and may optionally add and/or receive some of the signals. The optical communication access point or transceiver may be tap-in to the plurality of signals. The transmission of the plurality of signals may form the“backbone” signals. The“backbone” signals may be provided along one or more transmission paths, which may optionally be predefined or predetermined. The optical communication access point may be provided on one or more of the transmission paths. The backbone, e.g. the one or more transmission paths, may be shared by at least two or more optical communication access points or transceivers. The transmitted and received optical communications signals may be the same (e.g. re-transmitted or propagated without modification) or different (e.g., amplified, re-encoded, or the like).

Some optional features of the aspects or embodiments are set out below.

The apparatus may be configured to transmit and/or receive optical communications signals via optical wireless communication with one or more communications devices, mobile communications devices and/or the at least one other apparatus.

The apparatus may be a backbone optical communication access point or tranceiver configured to receive and transmit at least some or all of a plurality of optical communications signals.

The optical communication access point or transceiver may be configured to tap-in to the plurality of optical communications signals.

The plurality of signals may form backbone signals for transmission via at least part of the backbone.

The backbone signals may be provided along one or more transmission paths, which may optionally be predefined or predetermined.

The apparatus may be provided on one or more of the transmission paths, and optionally the backbone is shared by at least two or more of the apparatus.

The apparatus may comprise at least one transmitter for transmitting the optical communications signals and at least one receiver for receiving the optical communications signals. The apparatus may comprise at least one beam splitter or other optical signal spatial redirection device configured to selectively extract at least one signal from a plurality of optical communications signals that form backbone signals, and optionally wherein the at least one beam splitter other optical signal spatial redirection device is configured to extract one or more wavelengths from the optical communications signals where one or more of the wavelengths carries different data signals to at least one other wavelength. A beam splitter may be regarded as an example of an optical signal spatial redirection device.

The beam splitter may be configured to provide the at least one selectively extracted signal to one or more receivers of the apparatus or the at least one other apparatus.

At least one of the beam beam splitters may be configured to selectively provide at least one signal from a transmitter for a backbone signal so as to be provided along one or more transmission paths of the backbone.

The apparatus may be configured to enable access to a shared backbone, and may use at least one of the beam splitters to split incoming optical communications signals from at least one of the received optical communication signals and distribute the split optical communications signals among multiple receivers associated with the apparatus and/or at least one other apparatus.

At least one of the beam splitters may be configured to combine incoming optical communications signals from at least one of the received optical communication signals. At least one of the beam splitters may be configured to distribute the combined optical communications signals to one or more receivers associated with the apparatus and/or at least one other apparatus.

The apparatus may be configured such that optical communications signals are able to travel in both directions along a transmission path between two or more apparatus.

The apparatus may comprise at least two beamsplitters to facilitate transmittion of the optical communications signals between associated transmitters and receivers of the apparatus and/or at least one other apparatus.

The apparatus may comprise multiple apparatus provided on a transmission path corresponding to a single axis. One or more of the beamsplitter(s) may comprise one or more electrically controlled mirrors. The reflectivity of the one or more mirror(s) may be controllable or electrically controllable between transparency or partial transparency and full reflectivity.

The apparatus may be configured to tap in and out of the backbone to allow devices such as one or more communications devices, mobile communications devices, the apparatus and/or the at least one other apparatus to be easily added or removed to/from infrastructure associated with the backbone.

The apparatus may comprise one or more transmitter and receiver pairs for respectively sending and receiving the optical communications signals. The pairs may be positioned such that the pairs look in different directions.

One or more of the pairs may be manually or automatically adjustable in terms of direction to facilitate sending and/or receiving optical communications signals at different angles to/from the apparatus.

The apparatus may be configured to provide at least one of: amplify and forward (AF) and decode and forward (DF) type relays in optical communications.

The apparatus may be steerable and/or configured to provide beamsteering of the transmitted and/or received signals.

The apparatus may be configured to automatically adjust and track the location of another apparatus or communications device if it moves.

The apparatus may comprise a processing apparatus for providing some intelligence in finding and tracking other apparatus, communications devices and/or end-nodes within its line of sight.

The apparatus and/or the at least one other apparatus may be provided with a target having a signature detectable by a machine vision system such as implemented by the processing apparatus.

According to a third aspect there is provided a network comprising at least one apparatus and at least one other apparatus according to any aspect or embodiment described herein. The apparatus may be onfigured to enable access to a shared backbone, e.g. along at least one transmission path defined between the at least one apparatus and the at least one other apparatus.

According to a fourth aspect there is a method for connecting to a backbone of a network comprising an apparatus and at least one other apparatus. The apparatus may comprise an optical communications access point or transceiver. The apparatus may be configured to receive optical communications signals and transmit optical communications signals. The method may comprise communicating at least one of the received and transmitted optical communications signals via the at least one other apparatus of the backbone.

Some optional features of the aspects are set out below.

The method may comprise transmiting and/or receiving optical communications signals via optical wireless communication with one or more communications devices, mobile communications devices and/or the at least one other apparatus.

The method may comprise receiving and transmitting at least some or all of a plurality of optical communications signals.

The method may comprise tapping-in to the plurality of optical communications signals.

The method may comprise forming backbone signals for transmission via at least part of the backbone.

The method may comprise providing the backbone signals along one or more transmission paths, which may optionally be predefined or predetermined.

The method may comprise providing the apparatus on one or more of the transmission paths, and optionally sharing the backbone by at least two or more of the apparatus.

The method may comprise selectively extracting at least one signal from a plurality of optical communications signals that form backbone signals.

The method may comprise providing the at least one selectively extracted signal to one or more receivers of the apparatus or the at least one other apparatus. The method may comprise selectively providing at least one signal from a transmitter for a backbone signal so as to be provided along one or more transmission paths of the backbone.

The method may comprise enabling access to a shared backbone, and using at least one beam splitter or other optical signal spatial redirection device to split incoming optical communications signals from at least one of the received optical communication signals. The method may comprrise distributing the split optical communications signals among multiple receivers associated with the apparatus and/or at least one other apparatus, and optionally wherein the at least one beam splitter or other optical signal spatial redirection device is configured to extract one or more wavelengths from the optical communications signals where one or more of the wavelengths carries different data signals to at least one other wavelength.

The method may comprise combining incoming optical communications signals from at least one of the received optical communication signals. The method may comprise distributing the combined optical communications signals to one or more receivers associated with the apparatus and/or at least one other apparatus.

The method may comprise configuring the apparatus such that optical communications signals are able to travel in both directions along a transmission path between two or more apparatus.

The method may comprise facilitate transmittion of the optical communications signals between associated transmitters and receivers of the apparatus and/or at least one other apparatus with at least two beamsplitters.

The method may comprise controlling the reflectivity of one or more electrically controlled mirrors, between transparency or partial transparency and full reflectivity to facilitate reflection and/or transmission of optical communications signals via the one or more mirrors.

The method may comprise tapping in and out of the backbone to allow devices such as one or more communications devices, mobile communications devices, the apparatus and/or the at least one other apparatus to be easily added or removed to/from infrastructure associated with the backbone.

The method may comprise providing one or more transmitter and receiver pairs for respectively sending and receiving the optical communications signals, the pairs being positioned such that the pairs look in different directions. The method may comprise manually or automatically adjusting one or more of the pairs in terms of direction to facilitate sending and/or receiving optical communications signals at different angles to/from the apparatus.

The method may comprise providing at least one of: amplify and forward (AF) and decode and forward (DF) type relays in optical communications.

The method may comprise steering the apparatus and/or providing beamsteering of the transmitted and/or received signals.

The method may comprise automatically adjusting and track the location of another apparatus or communications device if it moves.

The method may comprise providing some intelligence in finding and tracking other apparatus, communications devices and/or end-nodes within its line of sight.

The method may comprise detecting a target of the apparatus and/or the at least one other apparatus, the target having a signature detectable by a machine vision system.

According to a fifth aspect there is provided a computer program product configured such that, when run on a suitable processing apparatus, the computer program product causes the processing apparatus to at least partially implement the method of any aspect or embodiment described herein.

A carrier medium may comprise the computer program product of aspect or embodiment described herein.

Some optional features of one or more of the aspects or embodiments are set out below.

The optical communications signals may be or comprise wireless or free space optical communications signals. The optical communications signals may be or comprise visual light communications signals or infra-red signals, or any other type of optical wireless communications (OWC) signals.

The optical communication access point or transceiver may comprise at least one transmitter for transmitting the optical communications signals. The transmitter may be or comprise an optical transmitter such as a laser, laser diode, light emitting diode, and/or the like. The optical communication access point or transceiver may comprise at least one receiver for receiving the optical communications signals. The receiver may be or comprise an optical receiver such as a photodiode, solar cell or array, or the like.

The optical communication access point or transceiver may comprise at least one beam splitter. At least one of the beam splitters may be configured to provide, e.g. selectively extract, at least one of signals from the plurality of signals, e.g. that form the backbone signals and may provide the obtained or selectively extracted signal to one or more or each of the receivers. At least one of the beam beam splitters (which may or may not be the same as the beam splitter used to provide or extract signals for the receiver) may be configured to provide, e.g. selectively provide, at least one signal from the transmitter to become a“backbone” signal, e.g. to be provided along one or more of the transmission paths.

The optical communication access point or transceiver may be configured to enable access to the shared backbone, and may make use of the beam splitters to split incoming light from at least one of the signals and may distribute it among multiple receivers. The same may be done in the reverse direction in order to combine beams. The optical communication access point or transceiver may be configured such that light is able to travel in both directions along the transmission path, e.g. to enable communication back and forth along a single axis. This may be achieved by doubling up the beamsplitters and associated photodetectors and emitters.

Multiple optical communication access point or transceiver may be provided on a single axis, e.g. without the need of having receivers and transmitters physically pointed in different directions. A tight optical integration can even ensure that multiple photodetectors and emitters are not required.

The beamsplitter(s) may comprise electrically controlled mirrors, e.g. wherein the reflectivity of the mirror(s) is controllable or electrically controllable, e.g. between transparency or partial transparency and full reflectivity. The mirrors may be used to direct the beam either left or right without the need for more than a single transmitter, e.g. laser. Mirrors may also be used in order to isolate parts of the network from certain transmissions, e.g. in order to increase security or the available capacity in the network. Such routing may be achieved via smart algorithms residing at each transceiver. Moreover mirrors may be used as simple low-cost relays to overcome deployment difficulties. The optical communication access point or transceiver may be configured to tap in and out of the optical backbone or bus, which may thereby allow devices to be easily added or removed to/from the infrastructure.

The transmitter and receiver pairs may be positioned such that they look in different directions. This may provide diversity in terms of transmitter and receiver pairs.

The optical communication access point or transceiver may be scalable. For example, it may be implemented with only two transmitter / receiver pairs pointed in opposite directions, or with a higher number of transmitter / receiver pairs, which may enable redundancy in the system. Moreover, each transceiver may be manually adjustable in terms of direction. This may enable user-friendly installation and relaxing the deployment constraints in terms of positioning. The optical communication access point or transceiver may be configured to provide amplify and forward (AF) as well as decode and forward (DF) type relays in optical communications.

The optical communication access point or transceiver may be steerable and/or configured to provide beamsteering of the transmission and/or received signals. The optical communication access point or transceiver may be configured to automatically adjust and track the location of another optical communication access point or transceiver or communications device if it moves. This may not only mean that reliability of communication may be higher, but also that deployments with low levels of mobility may become possible as well. Moreover, such an architecture may also be adapted for end-user communications device access as well.

Beamsteering may be implemented using mechanical means (for example a mechanically actuated rotational stage) or by making use of a mirror based MEMS device. The optical communication access point or transceiver may be comprise a low cost camera, which may be coupled with machine vision. The optical communication access point or transceiver may be be provided with a processor or other means for providing some intelligence in finding and tracking other access points, transceivers, communications devices and/or end-nodes within its line of sight.

For example, the optical communication access point or transceiver may be provided with a target, which may be made out of an infrared reflective material for example, or may be designed in such a way that its signature is easy to detect for a machine vision system. Better optical front-end integration may be achieved by using pigtailed optics or optics designed to interface with optical fibre. This may be achieved by using optical fibre up to the front-end electro-optical components, which may allow the electro-optical components and any other electronic components to be positioned away from the optical front end. This may allow more flexible integration as well as effectively smaller front-end devices such that they can be better integrated and may be made less obstructive. This may applicable to all of the examples presented above and/or below.

Components that rely on fluorescence and other similar phenomena may also be used in order to trap light and channel it in a more desired direction in order to achieve the above functionality and effectively create light antennas.

According to a sixth aspect of the present disclosure there is provided a network comprising at least one and preferably more than one optical communication access point or transceiver. The optical communication access points or transceivers may be configured to enable access to a shared backbone, e.g. along at least one transmission path.

It should be understood that the individual features and/or combinations of features defined above in accordance with any aspect of the present invention or below in relation to any specific embodiment of the invention may be utilised, either separately and individually, alone or in combination with any other defined feature, in any other aspect or embodiment of the invention.

Furthermore, the present invention is intended to cover apparatus configured to perform any feature described herein in relation to a method and/or a method of using or producing, using or manufacturing any apparatus feature described herein.

Brief description of the drawings

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

Figure 1 depicts a simplified physical representation of a network deployment;

Figure 2 is a schematic drawing depicting an example of an optical frontend to enable networking via beam splitting; Figure 3 is a schematic drawing depicting an example of beamsplitting with bi-directionality;

Figure 4 is a schematic drawing depicting an example of an optical frontend to enable networking via diversity;

Figure 5 is a schematic drawing depicting an example transceiver implementation; and

Figure 6 is a schematic drawing depicting a further example of a network comprising beamsplitters.

Detailed description of the drawings

Due to the directional nature of the communications, the transceiver design, as well as the overall prototype design, needs to be network enabled. The solutions described here provide several options for the transceiver design which achieve that.

In general, the networking scenario deployment envisioned will be similar to the network deployment (i.e.,“network”) 10 illustrated in Figure 1. The deployment presented can be readily adapted for any number of access points (APs) 12 and topology. What is important is that each AP 12 is connected to at least another AP 12. In practice, each AP is likely to be connected to at least another two APs 12 in order to enable full network connectivity with ideally some redundancy. One or more of the APs 12 may be connected by one or more backbone optical signal transmission paths 14. The AP 12 may comprise or function as a transceiver. The AP 12 or transceiver may be regarded as an apparatus forming part of a backbone for the network 10.

One or more embodiments described herein may facilitate optimised use of the network deployment 10 to selectively provide network capacity when and/or where required, for example, via APs 12 providing access to the network deployment 10 for one or more network- connectable devices (not shown) such as a cell phone, internet of things (loT) device, or the like.

Beam Splitting

One option to enable access to a shared backbone would be to make use of beam splitters to split incoming laser light and distribute it among multiple receivers. The same can be done in the reverse direction in order to combine beams. The concept is illustrated in Fig. 2, which depicts part of a network such as depicted by Figure 1. In Figure 2, a transmitter 16 such as a laser configured to transmit an optical signal 18a carrying data signals. This optical signal 18a is transmitted and/or reflected by a beam splitter 20a in the path of the transmitted optical signal 18a. Also shown by Figure 2 is a receiver 22 such as a photodetector configured to receive an optical signal 18b carrying data signals reflected and/or transmitted by a beam splitter 20b. In order to enable communication back and forth along a single axis 24, light should be able to travel in both directions. This can be achieved by doubling up the beamsplitters 20a, 20b and associated photodetectors (i.e., receiver 22, or the like) and emitters (i.e., transmitter 16, or the like). The configuration can be seen in Fig. 3, which shows two transmitters 16, 16’ arranged side-by-side and arranged to transmit optical signals 18a, 18a’ parallel to each other with corresponding beam splitters 20a, 20a’ arranged to transmit and/or reflect the optical signals 18a, 18a’ to another part of the network when required. Similarly, two receivers 22, 22’ are arranged side-by-side and arranged to receive optical signals 18b, 18b’ that propagate parallel to each other from beamsplitters 20b, 20b’ towards the respective receivers 22, 22’.

Such a configuration can be used to easily deploy multiple backbone APs 12 on a single axis without the need of having detectors and transmitters physically pointed in different directions. A tight optical integration can even ensure that multiple photodetectors and emitters are not required.

In addition to that, the deployment 10 could be further enhanced with the use of electrically controlled mirrors (e.g., in addition to or in place of the beam splitters 20a, 20a’, 20b, 20b’). If the reflectivity of the mirrors 20a, 20a’, 20b, 20b’ can be controlled electrically between transparency and full reflectivity, the mirrors 20a, 20a’, 20b, 20b’ can be used to direct the beam (i.e., the optical signal 18a, 18a’, 18b, 18b’) either left or right without the need for more than a single laser. Mirrors could also be used in order to isolate parts of the network from certain transmissions in order to increase security or the available capacity in the network. Such routing can be achieved via smart algorithms residing at each transceiver (e.g., which may be comprised in one or more of the APs 12). Moreover mirrors can be used as simple low-cost relays to overcome deployment difficulties.

The key concept here is that of tapping in and out of an optical backbone or bus thereby allowing devices to be easily added or removed to/from the infrastructure.

Pros: • Can lead to space and hardware efficient prototype

• May not require significant changes to current networking stack

• Has scope for future improvements (multiple transmitter (TX) and receiver (RX) devices coupled with adjustable mirrors may allow for the implementation of smart routing algorithms)

• Enables common bus deployments that can be hardware efficient as well as robust to single units failing

Cons:

• Multiple axis implementation may require a more complicated optical structure, but still achievable

• Multiple beamsplitter topologies may require further testing in order to gauge optical losses accurately

• Alignment might be time consuming depending on the beamwidth required

Another approach that would enable networking in a VLC/LiFi/FSO (i.e., visible light communication/LiFi/free space optical, respectively) system is to have diversity in terms of transmitter (TX) and receiver (RX) (i.e., transceiver) pairs 126 that are positioned such that they look in different directions. An example illustration of this approach can be found in Fig. 4, with the left-hand side figure depicting a top view of an AP 1 12 and the right-hand side figure depicting a side view of that AP 1 12. One or more of the transceiver pairs 126 may be provided in one or more optical backbone optical signal transmission paths 1 14

An advantage of this approach is that it is scalable. For example, it can be implemented with only two pairs 126 pointed in opposite directions, or with a higher number (eight in the depicted embodiment), which will enable redundancy in the system. Moreover, each transceiver pair 126 could be manually adjustable in terms of direction hence enabling user-friendly installation and relaxing the deployment constraints in terms of positioning.

Such an architecture is an enabler to realizing amplify and forward (AF) as well as decode and forward (DF) type relays in optical communications.

Pros: • Uncomplicated design

• Flexible both in terms of scalability and adjustability

• Has scope for future improvement (if all transceiver chains are complete, smart routing algorithms can be implemented that significantly boost network capacity)

• Alignment is likely to not be critical

Cons:

• Common bus deployment relies on reception and retransmission which may increase delay as well as reduce reliability

Beamsteerinq

Beamsteering is a solution that can provide incredible flexibility in the system as well as reliability. The ability to automatically adjust and track the location of an AP 12, 1 12 if it moves, does not only mean that reliability of communication is higher, but also that deployments with low levels of mobility become possible as well. Moreover, such an architecture can also be then adapted for end-user device access as well.

Beamsteering can be implemented in at least two different ways - using mechanical means (for example a mechanically actuated rotational stage) or by making use of a mirror based MEMS device. Moreover, if a low cost camera is added to the system coupled with machine vision, it is possible to give the system some intelligence in finding and tracking other APs or end-nodes within its line of sight.

An example transceiver implementation can be found in Fig. 5. The target (in red) 228, which in this embodiment forms a perimeter surround a transmitter 216 and a receiver 222 forming a transceiver“pair”, could be made out of an infrared reflective material for example, or be designed in such a way that its signature is easy to detect for a machine vision system. The transceiver pair and associated target 228 may be located on an access point such as depicted by Figure 4, or could be combined with a beamsplitter arrangement such as depicted by Figures 2 and 3.

Pros:

Extremely flexible • Reliable

• Can enable advanced multi-user low power architectures Cons:

• Certain implementations might be laggy (increased delay when switching between destinations)

• Relatively complex

• Steering mechanism could be a failure point in the system Integration

Better optical front-end integration could be achieved by using pigtailed optics or optics designed to interface with optical fibre. This can be achieved by using optical fibre up to the front-end electro-optical components thus allowing the electro-optical components and any other electronic components to be positioned away from the optical front end. This allows more flexible integration as well as effectively smaller front-end devices such that they can be better integrated and made less obstructive. This is applicable to all of the ideas presented thus far.

Components that rely on fluorescence and other similar phenomena can also be used in order to trap light and channel it in a more desired direction in order to achieve the above functionality and effectively create light antennas.

Figure 6 shows a further example implementation of a network deployment 310 comprising multiple transceivers 312 (which may be an example of an apparatus). The network deployment 310 has similar configuration to that depicted by Figure 3. Flowever, in this embodiment, there are three optical transceivers 312a-c arranged linearly along a single axis 324. In other similar words, a first (left-hand side) transceiver 312a is provided in optical communication with a second (i.e. central) transceiver 312b. Similarly, the second transceiver 312b is provided in optical communication with third transceiver 312c (right-hand side). Optical communications signals may be transmitted between the first and third transceivers 312a, 312c via the second transceiver 312b. There is direct line-of-sight optical communication path 330 between the first and second, and second and third transceivers 312a-c. One or more beamsplitters 320 (three in this embodiment) are provided in each communication path 330, each beamsplitter 320 being configured to selectively provide optical signals communication between a corresponding transceiver 312’ and one or more of the first to third transceivers 312a-c and/or one or more of the other transceivers 312’. It will be noted that the optical communications signals may comprise one or more wavelengths. Thus, it may be possible to provide communication using one or more different bands to optimise and/or maximise bandwidth usage. In this example, one of the transceivers 312’ may be configured to provide optical communications via one wavelength, another of the transceivers 312’ may be configured to provide optical communications via that wavelength plus another wavelength, and another of the transceivers 312’ may be configured to provide optical communications via those two wavelengths plus another wavelength. The reflectivity of the beamsplitters 320 may be appropriately selected to facilitate such transmission of one or more wavelengths. Although beamsplitters 320 are depicted, any other optical signal spatial redirection device may be used.

As depicted by the figure, three different wavelengths 332 may provide e.g., 10 Gbps communications directly between the first, second and/or third transceivers 312a-c. Additionally, three further wavelengths 334a-c may provide e.g., 1 Gbps communications with the transceivers 312’ via the beamsplitters 320. The properties of the optical communications signals (e.g., number and/or linewidth, etc) may vary according to application.

Although examples described herein may refer to use of a laser for transmitting or emitting an optical signal, other radiation sources such as light emitting diodes, or the like, may be used where appropriate. For example, any reference to a laser, emitter, transmitter or transceiver may, where appropriate, refer to any device for transmitting an optical signal.

Examples described herein may refer to detectors, photodetectors, receivers, or the like. Where appropriate, this shall be understood as referring to any device that can receive or detect an optical signal, and convert that signal into an electrical signal and/or re-transmit the optical signal. For example, any reference to a receiver, detector, photodetector, photodiode or transceiver may, where appropriate, refer to any device for receiving an optical signal.

A processing apparatus may comprise one or more processors or functional blocks configured to perform one or more operations or at least partially implement one or more methods described herein. A processing apparatus may comprise a digital signal processor (DSP), field programmable gate array (FPGA), application specific integrated circuit (ASIC) or other processing apparatus, for performing one or more steps or operations described herein. A computer program may be configured to provide any of the above described methods. The computer program may be provided on a computer readable medium. The computer program may be a computer program product. The product may comprise a non-transitory computer usable storage medium. The computer program product may have computer-readable program code embodied in the medium configured to perform the method. The computer program product may be configured to cause at least one processor to perform some or all of a method described herein.

Various methods and apparatus may be described herein with reference to block diagrams or flowchart illustrations (not shown) of computer-implemented methods, apparatus (systems and/or devices) and/or computer program products. It is understood that a block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by computer program instructions that are performed by one or more computer circuits. These computer program instructions may be provided to a processor circuit of a general purpose computer circuit, special purpose computer circuit, and/or other programmable data processing circuit to produce a machine, such that the instructions, which execute via the processor of the computer and/or other programmable data processing apparatus, transform and control transistors, values stored in memory locations, and other hardware components within such circuitry to implement the functions/acts specified in the block diagrams and/or flowchart block or blocks, and thereby create means (functionality) and/or structure for implementing the functions/acts specified in the block diagrams and/or flowchart block(s).

Computer program instructions may also be stored in a computer-readable medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable medium produce an article of manufacture including instructions which implement the functions/acts specified in the block diagrams and/or flowchart block or blocks.

A tangible, non-transitory computer-readable medium and/or carrier medium may include an electronic, magnetic, optical, electromagnetic, or semiconductor data storage system, apparatus, or device. More specific examples of the computer-readable medium would include the following: a portable computer diskette, a random access memory (RAM) circuit, a read-only memory (ROM) circuit, an erasable programmable read-only memory (EPROM or Flash memory) circuit, a portable compact disc read-only memory (CD-ROM), and a portable digital video disc read-only memory (DVD/Blu-ray). The carrier medium may be, comprise or be comprised in a non-tangible carrier medium such as an electromagnetic wave, electronic or magnetic signal, digital data and/or the like.

The computer program instructions may also be loaded onto a computer and/or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer and/or other programmable apparatus to produce a computer- implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the block diagrams and/or flowchart block or blocks.

In addition, it will be well understood by persons of ordinary skill in the art that whilst some embodiments may implement certain functionality by means of a computer program having computer-readable instructions that are executable to perform the method of the embodiments, the computer program functionality could be implemented in hardware (for example by means of a CPU or by one or more ASICs (application specific integrated circuits), FPGAs (field programmable gate arrays) or GPUs (graphic processing units)) or by a mix of hardware and software.

Accordingly, the present disclosure may be embodied in hardware and/or in software (including firmware, resident software, micro-code, etc.) that runs on a processor or processing apparatus, which may collectively be referred to as "circuitry," "a module" or variants thereof.

It should also be noted that in some alternate implementations, the functions/acts noted in the blocks may occur out of the order noted in the flowcharts. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Moreover, the functionality of a given block of the flowcharts and/or block diagrams may be separated into multiple blocks and/or the functionality of two or more blocks of the flowcharts and/or block diagrams may be at least partially integrated. Finally, other blocks may be added/inserted between the blocks that are illustrated.

The applicant discloses in isolation each individual feature described herein and any combination of two or more such features, to the extent that such features or combinations are capable of being carried out based on the specification as a whole in the light of the common general knowledge of a person skilled in the art, irrespective of whether such features or combinations of features solve any problems disclosed herein, and without limitation to the scope of the claims. The applicant indicates that aspects of the invention may consist of any such individual feature or combination of features. In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention.

Aspects or embodiments described herein may be combined or modified as appropriate. Features described in relation to one aspect or embodiment, even if not explicitly described in relation to another aspect or embodiment, may be applicable or used in that other aspect or embodiment.

Claims

1. An apparatus connectable to a backbone for a network comprising at least one other apparatus, the apparatus comprising an optical communications access point or transceiver, the apparatus being configured to receive optical communications signals and transmit optical communications signals, wherein at least one of the received and transmitted optical communications signals is communicated via the at least one other apparatus of the backbone.

2. The apparatus of claim 1 , wherein the apparatus is configured to transmit and/or receive optical communications signals via optical wireless communication with one or more communications devices, mobile communications devices and/or the at least one other apparatus.

3. The apparatus of claim 1 or 2, wherein the apparatus is a backbone optical communication access point or tranceiver configured to receive and transmit at least some or all of a plurality of optical communications signals.

4. The apparatus of claim 3, wherein the optical communication access point or transceiver is configured to tap-in to the plurality of optical communications signals.

5. The apparatus of claim 4, wherein the plurality of signals form backbone signals for transmission via at least part of the backbone.

6. The apparatus of claim 5, wherein the backbone signals are provided along one or more transmission paths, which may optionally be predefined or predetermined.

7. The apparatus of claim 6, wherein the apparatus is provided on one or more of the transmission paths, and optionally the backbone is shared by at least two or more of the apparatus.

8. The apparatus of any preceding claim, wherein the apparatus comprises at least one transmitter for transmitting the optical communications signals and at least one receiver for receiving the optical communications signals.

9. The apparatus of any preceding claim, wherein the apparatus comprises at least one beam splitter or other optical signal spatial redirection device configured to selectively extract at least one signal from a plurality of optical communications signals that form backbone signals, and optionally wherein the at least one beam splitter or other optical signal spatial redirection device is configured to extract one or more wavelengths from the optical communications signals where one or more of the wavelengths carries different data signals to at least one other wavelength.

10. The apparatus of claim 9, wherein the beam splitter is configured to provide the at least one selectively extracted signal to one or more receivers of the apparatus or the at least one other apparatus.

1 1 . The apparatus of claim 10, wherein at least one of the beam beam splitters is configured to selectively provide at least one signal from a transmitter for a backbone signal so as to be provided along one or more transmission paths of the backbone.

12. The apparatus of claim 9, 10 or 1 1 , wherein the apparatus is configured to enable access to a shared backbone, and use at least one of the beam splitters to split incoming optical communications signals from at least one of the received optical communication signals and distribute the split optical communications signals among multiple receivers associated with the apparatus and/or at least one other apparatus.

13. The apparatus of any one of claims 9 to 12, wherein at least one of the beam splitters is configured to combine incoming optical communications signals from at least one of the received optical communication signals and distribute the combined optical communications signals to one or more receivers associated with the apparatus and/or at least one other apparatus.

14. The apparatus of any preceding claim, wherein the apparatus is configured such that optical communications signals are able to travel in both directions along a transmission path between two or more apparatus.

15. The apparatus of claim 14, comprising at least two beamsplitters to facilitate transmittion of the optical communications signals between associated transmitters and receivers of the apparatus and/or at least one other apparatus.

16. The apparatus of claim 14 or 15, comprising multiple apparatus provided on a transmission path corresponding to a single axis.

17. The apparatus of any preceding claim, when dependent on claim 9, wherein one or more of the beamsplitter(s) comprises one or more electrically controlled mirrors, wherein the reflectivity of the one or more mirror(s) is controllable or electrically controllable between transparency or partial transparency and full reflectivity.

18. The apparatus of any preceding claim, wherein the apparatus is configured to tap in and out of the backbone to allow devices such as one or more communications devices, mobile communications devices, the apparatus and/or the at least one other apparatus to be easily added or removed to/from infrastructure associated with the backbone.

19. The apparatus of any preceding claim, wherein the apparatus comprises one or more transmitter and receiver pairs for respectively sending and receiving the optical communications signals, the pairs being positioned such that the pairs look in different directions.

20. The apparatus of claim 19, wherein one or more of the pairs are manually or automatically adjustable in terms of direction to facilitate sending and/or receiving optical communications signals at different angles to/from the apparatus.

21 . The apparatus of any preceding claim, wherein the apparatus is configured to provide at least one of: amplify and forward (AF) and decode and forward (DF) type relays in optical communications.

22. The apparatus of any preceding claim, wherein the apparatus is steerable and/or configured to provide beamsteering of the transmitted and/or received signals.

23. The apparatus of claim 22, wherein the apparatus is configured to automatically adjust and track the location of another apparatus or communications device if it moves.

24. The apparatus of any preceding claim, comprising a processing apparatus for providing some intelligence in finding and tracking other apparatus, communications devices and/or end- nodes within its line of sight.

25. The apparatus of claim 24, wherein the apparatus and/or the at least one other apparatus is provided with a target having a signature detectable by a machine vision system such as implemented by the processing apparatus.

26. A network comprising at least one apparatus and at least one other apparatus according to any preceding claim.

27. The network of claim 26, wherein the apparatus is configured to enable access to a shared backbone, e.g. along at least one transmission path defined between the at least one apparatus and the at least one other apparatus.

28. A method for connecting to a backbone of a network comprising an apparatus and at least one other apparatus, the apparatus comprising an optical communications access point or transceiver, the apparatus being configured to receive optical communications signals and transmit optical communications signals, the method comprising communicating at least one of the received and transmitted optical communications signals via the at least one other apparatus of the backbone.

29. The method of claim 28, comprising transmiting and/or receiving optical communications signals via optical wireless communication with one or more communications devices, mobile communications devices and/or the at least one other apparatus.

30. The method of claim 28 or 29, comprising receiving and transmitting at least some or all of a plurality of optical communications signals.

31 . The method of claim 30, comprising tapping-in to the plurality of optical communications signals.

32. The method of claim 31 , comprising forming backbone signals for transmission via at least part of the backbone.

33. The method of claim 32, comprising providing the backbone signals along one or more transmission paths, which may optionally be predefined or predetermined.

34. The method of claim 33, comprising providing the apparatus on one or more of the transmission paths, and optionally sharing the backbone by at least two or more of the apparatus.

35. The method of any preceding claim, comprising selectively extracting at least one signal from a plurality of optical communications signals that form backbone signals.

36. The method of claim 35, comprising providing the at least one selectively extracted signal to one or more receivers of the apparatus or the at least one other apparatus.

37. The method of claim 36, comprising selectively providing at least one signal from a transmitter for a backbone signal so as to be provided along one or more transmission paths of the backbone.

38. The method of claim 35, 36 or 37, comprising enabling access to a shared backbone, and using at least one beam splitter or other optical signal spatial redirection device to split incoming optical communications signals from at least one of the received optical communication signals and distributing the split optical communications signals among multiple receivers associated with the apparatus and/or at least one other apparatus, and optionally wherein the at least one beam splitter or other optical signal spatial redirection device is configured to extract one or more wavelengths from the optical communications signals where one or more of the wavelengths carries different data signals to at least one other wavelength.

39. The method of any one of claims 35 to 38, comprising combining incoming optical communications signals from at least one of the received optical communication signals and distributing the combined optical communications signals to one or more receivers associated with the apparatus and/or at least one other apparatus.

40. The method of any one of claims 28 to 39, comprising configuring the apparatus such that optical communications signals are able to travel in both directions along a transmission path between two or more apparatus.

41 . The method of claim 40, comprising facilitating transmittion of the optical communications signals between associated transmitters and receivers of the apparatus and/or at least one other apparatus with at least two beamsplitters.

42. The method of any one of claims 28 to 41 , comprising controlling the reflectivity of one or more electrically controlled mirrors, between transparency or partial transparency and full reflectivity to facilitate reflection and/or transmission of optical communications signals via the one or more mirrors.

43. The method of any one of claims 28 to 42, comprising tapping in and out of the backbone to allow devices such as one or more communications devices, mobile communications devices, the apparatus and/or the at least one other apparatus to be easily added or removed to/from infrastructure associated with the backbone.

44. The method of any one of claims 28 to 43, comprising providing one or more transmitter and receiver pairs for respectively sending and receiving the optical communications signals, the pairs being positioned such that the pairs look in different directions.

45. The method of claim 44, comprising manually or automatically adjusting one or more of the pairs in terms of direction to facilitate sending and/or receiving optical communications signals at different angles to/from the apparatus.

46. The method of any one of claims 28 to 45, comprising providing at least one of: amplify and forward (AF) and decode and forward (DF) type relays in optical communications.

47. The method of any one of claims 28 to 46, comprising steering the apparatus and/or providing beamsteering of the transmitted and/or received signals.

48. The method of claim 47, comprising automatically adjusting and track the location of another apparatus or communications device if it moves.

49. The method of any one of claims 28 to 48, comprising providing some intelligence in finding and tracking other apparatus, communications devices and/or end-nodes within its line of sight.

50. The method of claim 49, comprising detecting a target of the apparatus and/or the at least one other apparatus, the target having a signature detectable by a machine vision system.

51 . A computer program product configured such that, when run on a suitable processing apparatus, the computer program product causes the processing apparatus to at least partially implement the method of any one of claims 28 to 50.

52. A carrier medium comprising the computer program product of claim 51 .