Optical data communication methods, corresponding orchestrator, system, access point equipment and computer program

Abstract

The invention relates to a method for optical data communication between an OLT and a UE via an AP, comprising: - coordinating (50), via an orchestrator, the control plane of the optical data communication protocol and the control plane implemented between the AP and the UE, - optically communicating (51) data between the OLT and the UE via the AP, taking into account the coordination of the control planes.

Description

[0001] DESCRIPTION

[0002] TITLE: Optical data communication methods, orchestrator, system, access point equipment and corresponding computer program.

[0003] 1. Technical field

[0004] The present invention relates to the field of telecommunications and more particularly to methods and systems for optical data transmission, including fiber and wireless optical transmissions.

[0005] The applications are very varied, notably in the field of health (for detailed monitoring of brain activity, remote endovascular treatment of ischemic strokes, etc.), the field of industry 4.0 (in particular to increase process efficiency, energy efficiency and resource efficiency, etc.) and the field of extended reality (or XR for "extended Reality" in English) for education or gaming.

[0006] 2. Prior art

[0007] Fiber optic networks are playing an increasingly important role in providing broadband access to homes, offices, commercial buildings, factories, and smart cities.

[0008] Furthermore, the percentage of energy needed to operate the global information and communication technology infrastructure could be between 20 and 30% by 2030 (depending on certain assumptions regarding electricity production by 2030). Therefore, there is an urgent need to propose innovations in the parts of the network representing the largest share of this energy use, i.e., access networks (residential customers) and networks for businesses.

[0009] "6G" is the next generation of mobile communications technologies, with commercial deployments expected to begin in 2030. For this reason, 6G technologies are already the subject of intense research efforts with new uses and emerging candidate techniques, including Optical Wireless Communication (OWC), which is still in its infancy.

[0010] Optical wireless communication has a spectrum 2,600 times greater than radio spectrum (considering the 400 to 1,900 nm band) and can be used to add new capacity to existing radio systems rather than replace them. In addition, for indoor use, the propagation of optical wireless communication is limited by room walls and obstacles, which provides a first physical layer of security and the ability to reuse the same wavelengths in adjacent rooms, radically increasing the total data throughput capacity of the system. Technically, optical wireless communications use light (visible, infrared, or ultraviolet) to connect in free space without being confined in a waveguide.

[0011] For example, LEDs and lasers can be modulated to provide data communications, for outdoor point-to-point (known as Free-Space-Optics or FSO) with a capacity of up to 1.72 Tb / s. Similar systems have also been demonstrated for indoor point-to-multipoint (or LiFi for Light Fidelity) solutions with data rates of up to several Gb / s or between devices (e.g. OCC for Optical Camera Communication) with a few kb / s.

[0012] A new approach to wireless optical communication, known as Fiber Wireless, or FiWi, offers a direct connection between two optical fibers as an all-optical, point-to-point solution. According to this concept, at the transmitter, the light emitted by an optical fiber is collimated and then directed to a remote receiver. At the receiver, the incoming light is coupled back into an optical fiber. This FiWi operates bidirectionally, and speeds exceeding 1 Tb / s have been achieved with a theoretical capacity of up to 1.84 Pb / s. These links can operate independently of the applied modulation scheme and over a wide range of wavelengths, creating a very flexible method of interfacing with a large number of fiber optic systems such as Passive Optical Networks (PONs).

[0013] Passive optical network (PON) is now a mature technology for serving fiber to the home, known as "Fiber To The Home" or FTTH. This technical and commercial maturity for G-PON (Gigabit-capable PON) and in progress for XGS-PON (symmetrical 10-Gigabit-capable PON) makes it possible to address residential customers, university campuses and corporate networks. The office network topology is based on "N" endpoints with multiple Wi-Fi (for "Wireless Fidelity" in English) access points or other fixed or radio LAN interfaces, all connected to a single box that houses the single FTTH endpoint, with the optical network unit (or ONU) near / inside the corporate gateway.

[0014] Furthermore, this so-called "1 to N" topology offers the possibility of achieving speeds of the order of gigabit / s or more and dynamic allocation of bandwidth to endpoints is often necessary, depending on the company's uses. These are the main drivers of the so-called "Fiber To The Room" or FTTR technology. This FTTR technology can be based on PON technology operating like FTTH, using an optical splitter and TDM (for "Time Division Multiplexing" in English) for the downstream (or downlink) and TDMA ("Time Division Multiple Access" in English) for the upstream (or uplink).

[0015] Figure 1 illustrates an example of a smart home equipped with FTTR technology with multiple coordinated Wi-Fi access points, thus forming an integrated fiber and Wi-Fi network (also called FWIN) allowing Wi-Fi roaming, dynamic Wi-Fi power management, centralized traffic scheduling and end-to-end network slicing.

[0016] However, Wi-Fi roaming imposes higher requirements in terms of frequency allocation, latency and roaming accuracy. However, in a traditional multi-access point network, station access and roaming management functions are implemented on the access points independently. Therefore, when a station moves from one access point to another, it must be disconnected from the source access point and then reconnected to the destination access point. This process interrupts service transmission and deteriorates the user's network experience. In the context of an FTTR network, the issue of roaming is therefore a key issue to consider in order to limit or even avoid these disadvantages.

[0017] As mentioned above, the aforementioned future FiWi optical wireless communication technologies will use narrow steerable optical beams to provide reliable and high-capacity wireless services to the User Equipment (UE), replacing / complementing radio. To correctly transmit beams to the targeted UEs, the beam steerer needs accurate information about the position and movement of the UE. An OCC / LED optical camera communication technology can be used for the "control layer" or control plane, for example, as it is able to provide Acquisition Pointing Tracking (APT) functions with a low data rate (a few kbps) and to achieve multi-UE localization and tracking in a short time and with high accuracy.

[0018] Furthermore, regarding the "data layer" in a FiWi network, beamforming exploits the use of a narrow beam, in which each beam serves only one user equipment, so as to avoid capacity sharing between users. The directivity of the steered beams significantly improves link performance, such as data rate, energy efficiency, privacy and security. Several beam steering approaches exist, such as a beam steerer based on dual-axis steering mirrors. However, as previously mentioned, a limitation of the FiWi technique remains the point-to-point aspect which does not allow an optimal interface with an optical network such as PON for example, capable of handling multi-points.

[0019] 3. Statement of the invention

[0020] This patent application proposes a solution seeking to address this need through a wired and wireless optical network that is fully integrated into the optical infrastructure, or fully wired, capable of providing improved performance over currently proposed solutions, including high throughput, increased resilience, precise positioning and durability, and also capable of enabling new service capabilities inside buildings.

[0021] To do this, the invention proposes a method for optical data communication between an OLT optical network device and at least one user telecommunications device UE via at least one AP access point, comprising:

[0022] - the coordination, via an orchestrator, of the control plane of the optical data communication protocol and of the control plane implemented between said at least one access point AP and said at least one user telecommunications equipment UE, called coordination of the control planes,

[0023] - optical data communication between said optical network equipment OLT and said at least one user telecommunications equipment UE via said at least one access point AP, taking into account said coordination of the control planes.

[0024] Thus, the proposed solution allows the transmission of data optically from end to end, in a network implementing two different control planes, in an optimal manner thanks to the implementation of coordination between these two control planes.

[0025] For example, the proposed solution allows optimal data transmission in the case of an end-to-end fiber network but with two different communication protocols.

[0026] According to another example, said optical data communication between said at least one access point AP and said at least one user telecommunications equipment UE is wireless.

[0027] Thus, according to this example illustrated mainly in the remainder of the description, the proposed solution allows the transmission of data optically from end to end, from the optical network equipment receiving the data via a fiber network, to one or more user terminals via a wireless optical network, thanks to the implementation of a link between the control plane of the fiber optical communication and the control plane of the wireless optical communication space.

[0028] This link between the two control planes consists of coordinating them in such a way as to then allow optical communication of data between the network equipment and the user terminals, via an access point. The proposed solution therefore ensures on the one hand transparency to the communication protocol used for fiber optic communication by managing the control plane of this protocol via a coordination interface, also called coordinator or orchestrator, and on the other hand the taking into account of information from the control plane of the wireless optical network, for example to manage the number and mobility of user terminals and then their trajectories.

[0029] In particular, the coordination of the control planes comprises: the exchange and processing of first control information between said at least one access point AP and said at least one user telecommunication equipment UE, via control means equipping said at least one access point AP and said at least one user telecommunication equipment UE, the exchange and processing of second control information between said at least one access point AP and said optical network equipment OLT, via said orchestrator, the second control information taking into account the first control information and / or control information of the optical data communication protocol, and the wireless optical data communication takes into account the first and second control information and comprises the wireless optical transmission of data from said optical network equipment OLT,by said at least one access point AP to said at least one user telecommunications equipment UE and / or the wireless optical transmission of data to said optical network equipment OLT, by said at least one user telecommunications equipment UE to said at least one access point AP.,

[0030] Thus, the coordination of the control planes of fiber and wireless networks is based on the exchange and processing of information from these two control planes to coordinate the optical communication of data.

[0031] This coordination makes it possible in particular to supervise the optical beams of the wireless network, i.e. in the free space between the access point(s) and the user terminals, based on initial control information exchanged between the control means of the access point and those of the user terminal(s), such as, for example, information emitted by the LEDs and captured by the cameras for the identification and location of the user terminal(s), according to a particular embodiment.

[0032] For example, the control means in the access point and the user terminal correspond to FPGA Eval type cards which control in particular the optical beam steerer, the cameras and the LEDs. In addition, the exchange and processing of second control information between the optical network equipment and the access point(s) allows the coordination of data, for example by ensuring the implementation of a TDMA type time division multiplexing for a multi-user network topology.

[0033] We can therefore see that the coordination of the control planes allows for optimized and efficient transmission of optical data in free space to user equipment, via an access point, without altering the performance / capacities of the fiber optic transmission reaching the OLT optical network equipment.

[0034] The orchestrator, which allows the coordination of the control planes, communicates for example on the one hand with a controller on the AP access point side, which itself therefore acts as the interface between the FPGA Eval card and the orchestrator, and on the other hand with a controller on the OLT optical network equipment side, which itself therefore acts as the interface between the OLT and the orchestrator.

[0035] Furthermore, according to one embodiment, the coordination of the control planes comprises the synchronization of the optical data communication between said optical network equipment OLT and said at least one user telecommunication equipment UE when said at least one user telecommunication equipment UE moves, the synchronization taking into account the first and / or second control information.

[0036] Thus, thanks to the second control information exchanged between the optical network equipment and the access point (in particular information representative of a movement of a user terminal, "uploaded" via the access point), the coordination of the control planes makes it possible to readjust the data transmission by taking into account the changes in data propagation time between the optical network equipment and the user terminal when the latter moves, allowing optimal management of user roaming.

[0037] For example, the AP access point is equipped

[0038] - an optical fiber carrying a light beam,

[0039] - a mobile mirror controlled by said control means to direct the light ray exiting the optical fiber in a predetermined direction, and the method comprises: the alternative orientation of said light ray received by said access point AP via said optical fiber into at least two alternative light rays, the control of said mirror for wireless optical data communication to at least two user telecommunications equipment (UE1, UE2) via said two alternative light rays, the alternative orientation and the control taking into account said first and second control information.

[0040] Thus, for the sake of economy, an access point is equipped with only one mobile and controllable mirror, and the orchestrator controls the alternative orientation of the light beam, at the output of the optical fiber of the access point, into a plurality of alternative light beams intended to carry the optical data in free space to a plurality of user devices. The orchestrator also controls the orientation of the mirror to enable this wireless optical communication to the user terminals.

[0041] The solution thus provides a 1:N type network topology (one access point and N user terminals).

[0042] In addition, the method further comprises transmitting, via said two alternating light rays to at least two user telecommunication equipments, control information of the optical data communication protocol relating to time intervals respectively associated with said at least two user telecommunication equipments and the wireless optical data communication from said at least two user telecommunication equipments UE is implemented respectively during said time intervals.

[0043] In order to provide a 1:N network topology, each user terminal must know the time interval during which it will be able to transmit (i.e. its "timeslot" or "right to speak"). To do this, the orchestrator receives control information from the optical network equipment, for example TDMA type, and processes it so that it can be transmitted to each user terminal. The orchestrator must therefore duplicate this control information carried by the signaling header of the optical communication protocol so that each terminal receives it, processes it and integrates it into its transmission process.

[0044] According to this embodiment, the method further comprises a pairing phase, between said optical network equipment and each of said at least two user equipments, comprising the control of said mirror for wireless optical communication of data via said light beam successively to each of said at least two user telecommunications equipments.

[0045] Thus, the pairing phase between the access point and the user equipment is implemented successively with each user terminal without prior division of the light beam, so that all the power of the light beam is used during the pairing, thus facilitating the coverage eligibility of each user terminal. In another embodiment, the invention relates to an orchestrator belonging to an optical data communication network comprising an optical network equipment OLT, at least one user telecommunications equipment UE and at least one access point AP. Such an orchestrator is suitable for implementing the optical data communication method described above.Such an orchestrator may of course have the various characteristics relating to the optical data communication method according to the invention, which may be combined or considered in isolation, and in particular the orchestrator implements the coordination between the control plane of the optical data communication protocol and the control plane implemented between said at least one access point AP and said at least one user telecommunications equipment UE for the wireless optical transmission of data, called coordination of the control planes. In addition, the characteristics and advantages of this orchestrator are the same as those of the method and are not detailed further.

[0046] The orchestrator can for example be present in an AP access point or in a pOLT optical network device.

[0047] The invention also relates to an access point equipment in an optical data communication network comprising an OLT optical network equipment and at least one user telecommunication equipment UE, said access point equipment being intended to communicate with said at least one user telecommunication equipment UE and comprising: control means capable of exchanging control information with at least one LED and at least one camera equipping said at least one user telecommunication equipment, and comprising a controller capable of communicating with an orchestrator as described previously, an optical fiber carrying a light beam, at least one mobile mirror controlled by said control means to direct the light beam at the output of the optical fiber in a predetermined direction for wireless optical data communication with said at least one user telecommunication equipment.

[0048] Such access point equipment may of course have the various characteristics relating to the method for carrying out the accessibility verification according to the invention, which may be combined or considered in isolation. Thus, the characteristics and advantages of this access point equipment are the same as those of the method and are not detailed further.

[0049] The invention also relates to an optical data communication system comprising an optical network equipment OLT, at least one user telecommunication equipment UE, at least one access point AP as described above and at least one orchestrator as described above. In such a system, said at least one user telecommunication equipment UE and said at least one access point AP are intended to communicate in wireless optical mode, taking into account said coordination of the control planes implemented by the orchestrator described above, according to any one of the embodiments.

[0050] The invention also relates to at least one computer program comprising instructions for implementing the method described above, when this or these programs are executed by a processor, as well as at least one information medium readable by a computer comprising instructions of at least one computer program as mentioned above.

[0051] The method according to the invention can be implemented in various ways, in particular in wired form or in software form.

[0052] 4. List of figures

[0053] Other characteristics and advantages of the invention will appear more clearly on reading the following description of a particular embodiment, given as an illustrative and non-limiting example, and the appended drawings, among which: Figure 1 illustrates an example of a smart home equipped with FTTR technology with several coordinated Wi-Fi access points, according to the prior art; Figure 2 illustrates an example of a system for implementing the method according to the general principle of the invention; Figure 3 illustrates an example of implementation of the optical interface according to a first embodiment of the invention; Figure 4 illustrates an alternative embodiment of the example of Figure 3; Figure 5 presents the main steps of the method according to an embodiment of the invention; Figure 6 illustrates a second alternative of the first embodiment of the invention;Figure 7 illustrates another exemplary embodiment of the invention with several user telecommunications equipment; Figure 8 illustrates a second embodiment of the invention; Figure 9 presents the simplified structure of the different entities according to a particular embodiment.;

[0054] 5. Description of an embodiment of the invention

[0055] 5.1 General principle

[0056] The general principle of the invention is based on the creation of a link between two different control planes of two optical networks, such as for example the control plane of a fiber optic network which allows in particular the management of several user devices, and the control plane of a wireless optical network, which allows in particular the location and tracking of user terminals by the access points, so as to transmit the data from the fiber optic network via the wireless optical network, to each user terminal.

[0057] In the remainder of the document, the description of the different embodiments of the invention is based on an implementation in a PON type network for the fiber optic part, and the notations are therefore borrowed from this type of network (in particular for OLT, ONU equipment, etc.). It is important to note, however, that the invention is not dependent on the protocol used to transmit the data and can therefore be implemented in a network of a type other than PON. Figure 2 illustrates an example of a system for implementing the optical data communication method, comprising in particular:

[0058] - a pOLT optical network device, equipped with a CTRL_OLT controller to communicate with the ORCH orchestrator module described below, receiving data via an optical fiber and converting them so that they are distributed inside a house, a building or a business, via an optical distributor (or splitter) (1:4, 1:16, 1:64...). Such an optical network device, hereinafter referred to as pOLT or OLT, has the same functionalities as a conventional OLT network device of an FTTH type network, as well as the functionalities necessary for its integration into the system of the present invention, and in particular its CTRL_OLT controller;

[0059] - at least one API access point, conventionally positioned on the ceiling of a room, adapted to be connected via free space (wirelessly) with a number of active devices subsequently called user telecommunications equipment, such as the user telecommunications equipment UE1 illustrated in Figure 2;

[0060] - at least one orchestrator module ORCH, in charge of implementing a coordination of the control planes of the optical data communication network coming from the optical fiber and the wireless optical data communication network between the access point API and at least the user telecommunications equipment UE1, so as to allow optical data communication between the optical network equipment and at least the user telecommunications equipment UE1, via the access point API. Indeed, unlike the PON protocol in which the data layer and the control layer are transported by the same fiber, the optical data communication method of the invention must take into account the fact that two control planes coexist, that of the fiber part and that of the free space part.This orchestrator in charge of coordinating these two control planes can for example be implemented / present in an AP access point, which would have a role of "master" access point, or in a pOLT optical network device. We will now describe in more detail the different devices / modules implemented in the example system in Figure 1, and first of all the optical communication part in the free space, between the API access point(s) (AP2 ...) and the user telecommunication terminal(s) UE1 (UE2 ...).

[0061] For ease of reading, an embodiment with an API access point and a user telecommunications terminal UE1 is described below, but the invention allows, and this is one of its many advantages, end-to-end optical communication between one or more access points and several user telecommunications terminals.

[0062] For the implementation of downlink optical data communication, denoted D_D, in free space (or “downstream”, i.e. from the access point to the user equipment), the API access point is equipped with an optical beam steerer module M_AP1 (hereinafter denoted beam steerer) which points the optical beam including in particular data coming from the optical fiber via the pOLT optical network equipment, towards a desired user telecommunications equipment, here UE1.

[0063] A first advantage of this solution therefore lies in the optimization of its energy consumption, because unlike the “FTTR+Wi-Fi” solution described in relation to the prior art and Figure 1, this optical beam, defined as the “data layer” of the PON protocol for example, does not undergo optical-electrical-optical (OEO) or optical-electrical-radio (OER) conversion since this data is transmitted in wireless optical mode by API to UE1. The proposed solution will therefore have the same energy consumption regardless of the PON network speed (10, 25, 40, 50 or 100 Gb / s or the use of SFP (for “Small Factor Pluggable”) at 800 Gb / s coming from the core network) because it does not require OEO or OER converters, which consume energy.

[0064] A second advantage of this solution is that there is little loss of power in the optical beam from the fiber because it is transmitted in free space to the user equipment (only small losses can be noted due to collimation lenses and optical filters).

[0065] As is known, such a beam steerer M_AP1 can be manufactured using technologies such as liquid crystal on silicon (LCOS) mirrors based on spatial light modulator (SLM) or MEMS (MicroElectroMechanical Systems) based mirrors. MEMS mirrors are particularly interesting for use as beam steerers, both technically (less optical loss, better integration, etc.) but also because of their greater availability and lower price. The beam steerer M_AP1 is assisted, for example, by a so-called acquisition, pointing and tracking technique as described in relation to the prior art, of the APT type, based on a cam_AP1 camera of the OCC type which recognizes, locates and tracks the exact position of a targeted user telecommunications equipment.For fast and accurate tracking, the user telecommunication equipment is equipped with a light source such as a LED LED_UE1, associated with a unique identifier, which sends data at low speed (a few kbps) upwards for user equipment recognition (via the LED identifier information, the phase of the pairing process, an error correcting code, etc.). These exchanges of information and the processing of this information, subsequently called first control information and noted CTRL_1 in Figure 2 (illustrated by the black arrows), between the API access point and the user telecommunication equipment UE1 constitute in particular the control layer (or the control plane) of the wireless optical data communication network.

[0066] Furthermore, to exchange and process this first control information, the orientator M_AP1, the camera cam_APl and the LED LED_UE1 are for example controlled by FPGA (for "Field Programmable Gate Array" in English) evaluation boards both in the API access point (FPGA_Eval_APl) and in the user telecommunications equipment UE1 (FPGA_Eval_UEl), in a known manner and not detailed here.

[0067] In addition, the M_AP1 orientator includes a CTRL_AP1 controller communicating on the one hand with the FPGA_Eval_APl evaluation board and on the other hand with the orchestrator described below, so that the latter can coordinate the free space control plane and the fiber network control plane.

[0068] For the implementation of upstream / uplink data communication, noted D_M, in free space (or "upstream", i.e. from the user equipment to the access point), the solution of the invention also uses steerable narrow beams, which means that the functionalities and techniques described above in relation to the API access point are also found on the side of the user telecommunications equipment UE1.

[0069] Thus, the pONU corresponding to the user telecommunication equipment UE1 also has a beam steerer M_UE1 (MEMS type for example), an APT type technology based on an OCC type cam_UEl camera using an LED_AP1 and an FPGA_Eval_UEl board to control the data sent by the LED, the information received by the camera, the beam pointing and the data transmission.

[0070] It is thus possible to exchange first control information CTRL_1 between the API access point and the user telecommunications equipment UE1, and vice versa, through a control layer managed in particular by the controller CTRL_AP1 of the API access point and all the elements described in relation to this API access point and the user telecommunications equipment UE1.

[0071] Examples of first control information CTRL_1 exchanged between the LEDs LED_AP1, LED_UE1 and the cameras cam_APl, cam_UEl and uploaded to the controller CTRL_AP1 of the API access point are described below, in relation to figure 5 illustrating the main steps of the optical data communication method according to the invention.

[0072] We will now describe, in relation to Figure 2 and Figure 3, the optical interface implemented in particular thanks to the orchestrator for the implementation of the end-to-end optical network proposed by the invention.

[0073] The PON protocol can be used as well as the different optical budget / performance classes of typical SFPs with 28-, 32- or 35-dB attenuation between the OLT and the ONU but it is also recalled that the invention is not dependent on the protocol used (GPON, XGSPON, etc.) to transmit the data and can therefore be implemented in a network of a type other than PON.

[0074] In addition, the supervision of the optical link can also be carried out thanks to the received signal strength indicator or RSSI (for "Received Signal Strength Indicator" in English) calculated in the optical network equipment OLT and in the ONU UE1, using the optical power received and transmitted to the OLT and to the ONU. To do this, and as already indicated above, the controller CTRL_OLT of the OLT is in relation with the controller CTRL_AP1 of the access point API for the coordination of the transmission of optical data and the supervision of the optical beam, via the orchestrator ORCH which is the subject of the present invention. This coordination is implemented thanks to the exchange and processing of second control information CTRL_2 (illustrated by double wide striped arrows) coming from the PON control plane and therefore managed by the controller CTRL_OLT.

[0075] Examples of second control information CTRL_2 are described below, in relation to Figure 5 illustrating the main steps of the optical data communication method according to the invention.

[0076] An alternative embodiment is illustrated in Figure 4, in which the API access point is also an ONU. To achieve this, an optical signal sampling of approximately 1% of the power of the downlink optical beam (coming from the fiber via the OLT) is performed, so as to attach the beam steerer to an ONU, while steering the optical beam by 99% towards the end-user's ONU. According to this alternative, the API access point connected to the OLT as ONU1 is used as a relay to retransmit to the user equipment UE1 (as ONU2) 99% of the optical data coming from the OLT, for example when the OLT cannot connect directly to ONU2. This alternative thus makes it possible to connect a remote ONU whose optical path is blocked by an obstacle.

[0077] Figure 5 illustrates the main steps of the optical data communication method that can be implemented in particular in a system such as illustrated by Figures 2 to 7, i.e. between an optical network device OLT and at least one user telecommunications device UE via at least one access point AP.

[0078] To do this, and according to the different embodiments described in the present application, the method comprises a step 50 of coordination, via an orchestrator ORCH already described previously, of the control plane CPI of the optical data communication protocol (for example PON) and of the control plane CP2 implemented between the access point API and the user telecommunications equipment UE1 for the wireless optical transmission of data. This coordination of the control planes is implemented continuously to allow the communication of data in an end-to-end optical manner, i.e. for the implementation of a step 51 of optical data communication between the optical network equipment OLT and the user telecommunications equipment UE1 via the access point API, thus taking into account the coordination of the control planes.

[0079] As already mentioned previously, the coordination 50 of the control planes includes in particular the exchange and processing of first control information CTRL_1 between the API access point and the user telecommunications equipment UE1, via control means equipping these two elements and comprising for example the FPGA_Eval_APl and FPGA_Eval_UEl cards and the CTRL_AP1 controller already described. For example, first control information CTRL_1 exchanged between the LEDs LED_AP1, LED_UE1 and the cameras cam_APl, cam_UEl and uploaded to the CTRL_AP1 controller of the API access point allows in particular the location of the user telecommunications equipment, its trajectory and the control of the beam orientators (mirrors) of the API access point and the user telecommunications equipment UE1 to focus the optical data beams, in uplink or downlink signal.

[0080] The coordination 50 of the control planes also comprises the exchange and processing of second control information CTRL_2 between the access point AP and the optical network equipment OLT, via the orchestrator ORCH, this second control information CTRL_2 taking into account the first control information CTRL_1 and / or control information of the optical data communication protocol, such as for example information of the received signal level type RSSI or arrangement of the TDMA protocol making it possible to transmit a frame comprising a “beacon” which comprises the time intervals (timeslots) associated with each UE, for the uplink communications.Thus, the coordination 50 of the control planes implemented by the orchestrator ORCH, in relation to the controllers CTRL-OLT and CTRL-AP1, takes into account first and second control information so as to be able to implement, for example, roaming prediction (also called roaming) thanks to the precise location of a user equipment, or even the anticipation of network outage due to coverage limits for a user equipment so as to switch it to another access point in a transparent manner for the user equipment and without network outage.

[0081] Indeed, a notable difference in the context of the invention, already mentioned, with a conventional PON type network, lies in the fact that the user telecommunications equipment UE1 (i.e. the ONU), moves. The propagation time between the OLT and the ONU therefore changes, both in uplink and downlink transmission.

[0082] According to a particular characteristic of the invention, the coordination of the control planes therefore comprises the synchronization of the optical data communication between the OLT and the user telecommunications equipment UE when the latter moves, the synchronization taking into account the first and / or second control information and being implemented using the orchestrator. For example, according to a first approach, the beam steerer M_AP1 or the controller CTRL_OLT of the OLT requests the OLT to establish a new time estimation process with the ONU UE1. Typically, if the ONU moves at 3.6 km / h (lm / s), an optical beam has a difference of lm per second, corresponding to a propagation difference of 3.34 ns for an optical beam in free space.Thus, a telemetry process must be put in place to synchronize the OLT and the ONU, for example whenever this difference is greater than a predetermined threshold (typically 0.8 ns for 1.25 Gbit / s).

[0083] In a second approach, the estimation of the propagation time difference between the OLT and the ONU is performed by the camera cam_APl of the API access point. In this case, the controller CTRL_AP1 exchanges second control information CTRL_2 with the controller CTRL_OLT of the OLT, via the orchestrator ORCH, to modify the propagation time to be taken into account.

[0084] An advantage of the solution according to the invention therefore lies in the possibility of permanently synchronizing the OLT and the ONU for optimal optical communication, thanks to the orchestrator and the controllers of the OLT and the API access point.

[0085] As already indicated, the solution of the invention makes it possible to target not only a single user communication equipment from an access point, but also several user communication equipment, according to different embodiments described below. According to a first alternative (not shown) of the first embodiment, an access point is equipped with an optical fiber carrying a light beam, a splitter separating the beam into several light beams and several beam steerers so as to be able to emit several beams to several users, corresponding to as many ONUs, at the same time. In the implementation of the present invention, the beam steerers correspond to several mirrors controllable by the orchestrator. This embodiment results in a loss of the optical budget (loss proportional to the number of optical beams) but offers the advantage of optimizing the throughput.Thus, the orchestrator controls, in conjunction with the access point controller, the orientation of each mirror of an access point for communication with a previously identified user telecommunications equipment. According to this first alternative of the first embodiment (configuration called "multi 1 to 1"), the control of the mirrors takes into account first and second control information managed by the ORCH orchestrator. For example, the control of the mirrors takes into account the precise location of each user equipment, obtained in particular thanks to the exchanges of first control information between the cameras and the LEDs of the access point and each user equipment, to orient the beam as precisely as possible towards each chosen user equipment, and in particular to follow any movement of these user equipment.Similarly, the control of the mirrors also takes into account second control information provided by the network equipment to the access point, via the orchestrator and the controller of the access point, relating for example to a previously carried out pairing and a time interval previously allocated to each user equipment for sending data in the upstream direction.

[0086] According to a second alternative of the first embodiment, more economical, an access point AP is equipped with only a single mirror / beam orientator M_AP1 controlled by the control means CTRL_AP1, to alternately direct the light beam at the output of the optical fiber in as many predetermined directions as there are user equipments in the network, for example two (UE1, UE2) as illustrated in figure 6. This embodiment leads to a reduction in the throughput for the user but offers the advantage of conserving the optical budget.

[0087] The single mirror of the access point is therefore controlled by the ORCH orchestrator and the CTRL_AP1 controller of the access point to enable wireless optical data communication alternately to the two user telecommunications equipment (UE1, UE2) via the two alternative light rays.

[0088] According to this second alternative of the first embodiment, the alternative orientation of the light beam (into as many alternative light rays as there are users) and the control of the mirror also take into account first and second control information managed by the ORCH orchestrator. Indeed, such a configuration requires in particular duplicating the beacon transmitted by the PON control layer (i.e. the broadcast signaling header) informing each ONU of its “right to speak” (i.e. its time interval or timeslot), to transmit it successively to each ONU by directing the beam each time. To do this, the orchestrator retrieves the TDMA control information via the OLT controller and then transmits it, via the CTRL_AP1 controller of the access point, to the beam steerer M_AP1.

[0089] Thus, the method of the invention provides for the transmission, via the at least two alternating light rays, to at least two user telecommunications equipment, of control information taking into account this second control information relating to time intervals associated respectively with the two user telecommunications equipment, so that the wireless optical communication of data from the two user telecommunications equipment is properly implemented respectively during the time intervals allocated to each user equipment UE1, UE2.

[0090] We now describe the pairing phase necessary with the pOLT so that each ONU can then communicate, in relation to figure 7, according to the two variants described below, in which the pairing phase requires the control of the mirror M_AP1 of the API access point for the wireless optical data communication via the light beam successively to each of the two user telecommunications equipment.

[0091] According to a first variant, during the initial pairing phase, the beam steerer M_AP1 selects, via the controller CTRL_AP1, one of the ONUs, for example UE1, and establishes a direct connection between this ONU and the OLT. To do this, as already described above, the OLT and the ONU must first carry out a telemetry process before being able to exchange data. This telemetry process, like that of the pairing, uses in particular the first and second control information CTRL_1, CTRL_2, exchanged and processed by the different controllers CTRL_OLT and CTRL_AP1 and the orchestrator ORCH.

[0092] Then, when the second ONU, UE2, needs to be connected to the OLT, the beam steerer M_AP1 stops the first link with UE1 and changes the beam direction, still via the controller CTRL_AP1, to establish a second direct link (shown in dotted line in Figure 7) between this second ONU UE2 and the OLT. In the same way as for the connection between the OLT and the ONU UE1, the OLT and the ONU UE2 must first perform a ranging process before they can exchange data. According to this first variant, the pairing phase is implemented between the OLT and a user equipment when the latter wants to be connected to the OLT and the link established between this OLT and this user equipment is suspended if another user equipment also wants to be connected to the OLT.

[0093] According to a second variant, during the initial pairing phase, the beam steerer M_AP1 selects, via the controller CTRL_AP1, one of the ONUs, for example UE1, and establishes a direct link between this ONU and the OLT. This step can also be implemented when a new ONU is discovered, i.e. when a new user equipment enters the network and is detected by the access point API. In this case, the beam steerer M_AP1 selects, via the controller CTRL_AP1, the new detected ONU UE1 and establishes a direct link between this ONU UE1 and the OLT. In both cases, this direct link is established only for a few milliseconds, which allows the pairing process between the OLT and this ONU UE1 to be carried out, and in particular the ranging process as described above for the first variant.

[0094] Then, the OLT updates and sends the respective time slot allocation information of the ONUs, in order to inform the ONU UE1 of its “talking time” and requests the AP to modify the beam steerer M_AP1 in order to select a new ONU, for example UE2 and establish a direct link between this ONU UE2 and the OLT.

[0095] The solution according to this second variant advantageously allows to have already launched the telemetry process between each ONU and the OLT and therefore allows to then reduce the attachment / connection time of an ONU not connected with the OLT.

[0096] We will now describe, in relation to Figure 8, a second embodiment of the invention in which an OLT can be connected to both one or more fiber ONUs, for example UE3, and one or more ONUs in wireless optical transmission mode according to the invention, for example UE1. To do this, an optical coupler / splitter OPT_SPLITTER is added in the fiber part, between the OLT and the free-space optical beam, so that a single OLT port can be connected to several ONUs either by a direct optical fiber, UE3, or by a free-space optical beam, UE1. One of the advantages of this embodiment lies in the fact that it is not necessary to modify the network architecture to add an ONU in fiber communication or in free space.

[0097] Furthermore, an alternative (not shown) to this embodiment is to add a range extender function between the optical coupler and the beam steerer at the AP, as is possible in another context or architecture. Using this range extender makes the optical budget for free-space transmission independent of fiber attenuation and optical splitter loss. In other words, the range extender allows the free-space beam to utilize the entire optical budget of the PON transceiver and potentially increase the free-space optical transmission distance.

[0098] 5.2 Simplified structure of the corresponding entities

[0099] Finally, in relation to Figure 9, we present the simplified structures of an entity, for example an orchestrator, user equipment or an access point according to an embodiment of the invention.

[0100] As illustrated by Figure 9, such an entity comprises at least one memory 91 comprising a buffer memory, at least one processing unit 92, equipped for example with a programmable computing machine or a dedicated computing machine, for example a processor P, and controlled by the computer program 93, implementing steps of the optical data communication method according to at least one embodiment of the invention.

[0101] Upon initialization, the code instructions of the computer program 93 are for example loaded into a RAM memory before being executed by the processor of the processing unit 92.

[0102] If the entity is an orchestrator, the processor of the processing unit 92 implements steps of the optical data communication method, described previously, according to the instructions of the computer program 93, for coordination between the control plane of the optical data communication protocol and the control plane implemented between said at least one access point AP and said at least one user telecommunications equipment UE for the wireless optical transmission of data, called coordination of the control planes.

[0103] If the entity is an optical network device or an access point device or a user telecommunications device, the processor of the processing unit 92 implements steps of the optical data communication method, described previously, according to the instructions of the computer program 93, for the wireless optical data communication between said optical network device OLT and said at least one user telecommunications device UE via said at least one access point AP, taking into account said coordination of the control planes, said optical data communication being wireless between said at least one access point AP and said at least one user telecommunications device UE.

Claims

CLAIMS 1. Method for optical data communication between an optical network equipment OLT and at least one user telecommunications equipment UE via at least one access point AP, characterized in that it comprises: - the coordination (50), via an orchestrator, of the control plane (CPI) of the optical data communication protocol and of the control plane (CP2) implemented between said at least one access point AP and said at least one user telecommunications equipment UE, called coordination of the control planes, - optical data communication (51) between said optical network equipment OLT and said at least one user telecommunication equipment UE via said at least one access point AP, taking into account said coordination of the control planes.

2. Optical data communication method according to claim 1, characterized in that said optical data communication between said at least one access point AP and said at least one user telecommunications equipment UE is wireless.

3. Optical data communication method according to claim 1, characterized in that said coordination of the control planes comprises: the exchange and processing of first control information between said at least one access point AP and said at least one user telecommunication equipment UE, via control means equipping said at least one access point AP and said at least one user telecommunication equipment UE, the exchange and processing of second control information between said at least one access point AP and said optical network equipment OLT, via said orchestrator, the second control information taking into account the first control information and / or control information of the optical data communication protocol,and in that said wireless optical data communication takes into account the first and second control information and comprises the wireless optical transmission of data from said optical network equipment OLT, by said at least one access point AP to said at least one user telecommunications equipment UE and / or the wireless optical transmission of data to said optical network equipment OLT, by said at least one user telecommunications equipment UE to said at least one access point AP., 4. Optical data communication method according to claim 1, characterized in that said coordination of the control planes comprises the synchronization of the optical data communication between said optical network equipment OLT and said at least one user telecommunication equipment UE when said at least one user telecommunication equipment UE moves, the synchronization taking into account the first and / or second control information.

5. Optical data communication method according to claim 3, characterized in that said access point AP is equipped - an optical fiber carrying a light beam, - a mobile mirror controlled by said control means to direct the light ray exiting the optical fiber in a predetermined direction, and in that the method comprises: the alternative orientation of said light ray received by said access point AP via said optical fiber into at least two alternative light rays, the control of said mirror for wireless optical data communication to at least two user telecommunications equipment (UE1, UE2) via said two alternative light rays, the alternative orientation and the control taking into account said first and second control information.

6. Optical data communication method according to claim 5, characterized in that it further comprises the transmission, via said two alternating light rays to at least two user telecommunications equipment, of control information of the optical data communication protocol relating to time intervals associated respectively with said at least two user telecommunications equipments and in that the wireless optical data communication from said at least two user telecommunications equipments UE is implemented respectively during said time intervals.

7. Optical data communication method according to claim 5, characterized in that it comprises a pairing phase, between said optical network equipment and each of said at least two user equipments, comprising the control of said mirror for wireless optical data communication via said light beam successively to each of said at least two user telecommunication equipments.

8. Orchestrator belonging to an optical data communication network comprising an optical network equipment OLT, at least one user telecommunications equipment UE and at least one access point AP, the orchestrator being characterized in that it implements the coordination between the control plane of the optical data communication protocol and the control plane implemented between said at least one access point AP and said at least one user telecommunications equipment UE for the wireless optical transmission of data, called coordination of the control planes.

9. Access point equipment in an optical data communication network comprising an OLT optical network equipment and at least one user telecommunications equipment UE, said access point equipment being intended to communicate with said at least one user telecommunications equipment UE and being characterized in that it comprises: control means capable of exchanging control information with at least one LED and at least one camera equipping said at least one user telecommunications equipment, and comprising a controller capable of communicating with an orchestrator according to claim 8, an optical fiber carrying a light beam, at least one movable mirror controlled by said control means to direct the light beam at the output of the optical fiber in a predetermined direction for wireless optical data communication with said at least one user telecommunications equipment.

10. Optical data communication system comprising an optical network equipment OLT, at least one user telecommunication equipment UE and at least one access point AP according to claim 9, and characterized in that it comprises at least one orchestrator according to claim 8 and in that said at least one user telecommunication equipment UE and said at least one access point AP are intended to communicate in wireless optical mode, taking into account said coordination of the control planes.

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