Patent Description:
Industry <NUM> describes a trend towards automatic in manufacturing technology. This is occurring at the same time as the introduction of <NUM> radio technology. In the context of smart manufacturing, <NUM> allows a reduced infrastructure cost by enabling replacement of cables with industry-grade cellular connectivity. Less cabling in the factory also implies increased floorplan layout flexibility and easier deployment of new factory equipment like robots and sensors.

Elements of factories of the future may include Automated Guided Vehicles (AGV), for example, moving vehicles which enable a "multidirectional layout" of a production line instead of the current "linear layout" provided by conventional conveyors. AGVs provide for shuttling of the various materials inside and among the work cells and between the production line and the warehouses/loading bays.

Example AGV may have a connectivity to a network via Wi-Fi or Bluetooth to receive high level instructions (e.g. a path sequence) and communicate acknowledgments, sensors data, alarms etc. All the navigation, safety, and control software are processed on-board of the AGV. This requires powerful processors on board, a high battery consumption, and limited upgradability in the AGV lifetime.

By connecting an AGVs with <NUM> to a network, most of the internal computation can me moved to a central data processing center, e.g. in a cloud, where the computation can benefit from an enormous amount of computing power. <NUM> facilitates moving large data amounts between the machine and the cloud and, in addition, ensures the low latency needed to send instruction to the AGV without delays.

Examples of functionalities which can be moved to cloud are visual navigation, collision avoidance (both machine-machine and machine-human collisions), remote control and supervision. Coordination among AGVs, to accomplish a shared task, is also facilitated by having a central control point, for example, in the cloud. Coordination between the AGVs enables platooning or swarming of AGVs.

Cellular technologies, such as <NUM> or <NUM>, ensure better coverage over an area than Wi-Fi by providing a smooth handover between cells. For example, for indoor small cells, radio control ensures smooth handover. This is particular important for AGVs which move around the factory, which is significantly larger than an area which could be provided by a single Wi-Fi access point. On the contrary, Wi-Fi solutions present "dead spots" because AGVs must reconnect with each individual access point. This situation is not suited to deploy AGVs or "cloud robotics".

A possible implementation of "cloud-driven" AGVs requires data rates of tens or even hundreds of Mbps for each vehicle. It is useful to efficiently provide connectivity for these high data rates.

<CIT> discloses a method that utilizes a hybrid connection infrastructure that uses free space communication optical laser links and wireless data links.

<CIT> discloses a communication system for communicating data using a radio frequency interface and a visible-light interface.

<CIT> discloses a wireless data access system where a wireless device is connected using a free-space optical communication link.

<CIT> discloses a method by a coordination node for controlling communications between optical access points and UEs.

<CIT> discloses an optical fiber-based wireless systems supporting radio frequency communications with clients over optical fiber, including Radio-over-Fiber communications.

One aspect of the present disclosure provides an access network for communication with a wireless device. The access network comprising a plurality of antennas each configured to provide a cell for radio frequency communication with the wireless device, and a plurality of sets of optical elements configured for optical communication with the wireless device. The access network comprises a processor and a memory, said memory containing instructions executable by said processor whereby said apparatus is operative to connect to the wireless device with both the radio frequency communication and optical communication, and connect to the wireless device with the radio frequency communication at least in a downlink direction, and connect to the wireless device with the optical communication at least in an uplink direction.

Another aspect of the present disclosure provides a method in an access network for communication with a wireless device. The method comprises establishing cells for radio frequency communication with the wireless device, and establishing optical links using a plurality of sets of optical elements configured for optical communication with the wireless device. The method further comprises connecting the access network to the wireless device with both the radio frequency communication and optical communication, and wherein the access network connects to the wireless device with the radio frequency communication at least in a downlink direction, and connects to the wireless device with the optical communication at least in an uplink direction.

Another aspect of the present disclosure provides a wireless device for communication with an access network. The wireless device comprises an antenna configured to provide radio frequency communication with a cell of the access network; and one or more optical elements configured for optical communication with the access network. The wireless device comprises a processor and a memory, said memory containing instructions executable by said processor whereby said apparatus is operative to connect to the access network with both the radio frequency communication and optical communication by connecting to the access network with the radio frequency communication at least in a downlink direction, and to the access network with the optical communication at least in an uplink direction.

Another aspect of the present disclosure provides a method in a wireless device for communication with an access network. The method comprises establishing radio frequency communication with the access network, and establishing optical communication with the access network. The method further comprises connecting the wireless device to the access network with both the radio frequency communication and optical communication by connecting to the access network with the radio frequency communication at least in a downlink direction, and to the access network with the optical communication at least in an uplink direction.

Another aspect of the present disclosure provides a network node of an access network for communication with a wireless device. The network node comprises an antenna configured to provide a cell for radio frequency communication with the wireless device, and a set of one or more optical elements configured for optical communication with the wireless device. The network node comprises a processor and a memory, said memory containing instructions executable by said processor whereby said apparatus is operative to connect to the wireless device with both the radio frequency communication and optical communication, and connect to the wireless device with the radio frequency communication at least in a downlink direction, and connect to the wireless device with the optical communication at least in an uplink direction.

Another aspect of the present disclosure provides a method in a network node of an access network for communication with a wireless device. The method comprises establishing a cell for radio frequency communication with the wireless device, and establishing an optical link using a set of optical elements configured for optical communication with the wireless device. The method further comprises connecting the network node to the wireless device with both the radio frequency communication and optical communication, and wherein the access network connects to the wireless device with the radio frequency communication at least in a downlink direction, and connects to the wireless device with the optical communication at least in an uplink direction.

Examples of the present disclosure provide an optical offload of radio resources. In some aspects, a radio antenna is complemented with optical elements providing an optical link. In one example, RF radio beams are used at least in downlink (from the antenna to a wireless device) while optical based communication is used at least in uplink (from the wireless device to the antenna).

The present disclosure provides an access network and a wireless device which can communicate with a high data rate over a relatively large area. This is particularly applicable to indoor applications in a factory plant or in an indoor warehouse. Examples use an Advanced Antenna System (AAS) for a radio network.

<FIG> illustrates an exemplary industry setting of a factory or plant layout. The plant provides a large indoor area over which multiple wireless devices <NUM> which can move. The wireless device <NUM> may, for example, be (or included within) a AGV, robot, industrial device, a vehicle, and may also referred to as a User Equipment (UE) or wireless terminal. These are examples of a type of device which might benefit from the connectivity provided by the present disclosure. The term wireless device will be used for the mobile device which is connected to the access network.

Aspects of the disclosure provide an access network, which may also be referred to as a network or a radio-optical access network. The access network comprises a plurality of network nodes comprising or connected to radio antennas, also referred to as antennas. The antennas may be located in different locations around the plant, to provide radio coverage throughout the required area. The antennas transmit (and in some examples also receive) radio signals to provide a cell for communication with one or more wireless device. The antennas may be considered as providing a small radio cell (i.e. small cell). The access network provides a plurality of radio cells which cover the area over which the wireless devices are intended to move. The access network may further comprise radio frequency circuitry and/or baseband circuitry, connected by wired or wireless connections. The access network may comprise one or more base stations. The access network may comprise a connection or interface to a processing node, configured to perform computation on data received from and/or transmitted to the wireless devices. References to antennas, antenna units and network nodes may be used interchangeably.

In <FIG>, the antenna unit <NUM> comprises a set of a plurality of optical elements <NUM>. In this example, the optical elements <NUM> are arranged at the edges, e.g. corners, of the array of the antenna elements. The example shown is an antenna unit comprising three optical elements. Further examples may comprise <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or more optical elements, e.g. optical receivers or transceivers. In some examples, the antenna unit <NUM> uses one or more of the optical elements <NUM> for providing an optical link. Further optical elements <NUM> may be present which can be regarded as spare.

In <FIG>, a further example of antenna unit <NUM> comprises a set of a plurality of optical elements <NUM>. The optical elements <NUM> are arranged adjacent to each one of radio antenna elements <NUM>. In some examples, the antenna unit <NUM> may be considered as comprising a plurality of communication modules <NUM>, each communication module comprising one or more antenna elements <NUM> and one or more optical element <NUM>. The communication modules <NUM> are arranged in an array. As such, the radio antenna elements and optical elements are arranged in an array. The optical elements <NUM> may be considered as integrated with the radio antenna element. The use of a plurality of identical modules comprising both an antenna element and an optical element provides for preserving how the antenna elements are built and modularity. The use of modules <NUM> allows for more flexibility, more capacity for future scalability, and more robustness. For example, the arrangement allows for a higher number of optical elements (e.g. photo receivers to receive the same optical link), compared to the example of <FIG>. In some aspects, the large number of optical elements provides for redundancy or simplifies manufacturing by using the same communication module <NUM>.

As shown in <FIG>, an antenna unit <NUM>,<NUM> comprises a plurality of antenna elements <NUM> or radio antenna elements. The antenna elements <NUM> may also be referred to as an antenna. The antenna elements may be arranged in two dimensions over an antenna surface or substrate. The antenna elements may be arranged in an array, for example, comprising antenna elements arranged in rows and columns of individual antenna elements. In some examples, the antenna elements are dual-polarized antenna elements. In some examples, the antenna may be an Advanced Antenna System (AAS). The AAS may comprise an antenna array closely integrated with the hardware and software required for transmission and reception of radio signals, and signal processing algorithms to support the execution of AAS features (such as beamforming and MIMO). As such, the AAS is able to utilize the antenna array to perform functions such as beamforming and MIMO communication.

For example, beamforming can direct radio energy through a radio channel toward a specific wireless device (as a receiver) improving throughput and capacity. Similarly, when receiving, beamforming is the ability to collect the signal energy from a specific wireless device (as a transmitter). The beams formed by an AAS can be continually adapted to the surroundings or radio channel to give high performance in both uplink and downlink.

In some examples, the optical elements <NUM> of a set (e.g. on an antenna unit <NUM>;<NUM>) are configured to transmit/receive individual signals, i.e. are individually controlled. The optical elements may provide spatial multiplexing (e.g. optical MIMO). The plurality of optical elements allows for simultaneous optical links with a plurality of wireless devices by using spatial multiplexing (e.g. from many AGVs). In the case where two or more optical elements receive the same information (from a common optical link), this increases the robustness of the link (i.e. multi-path reception). The signal from the plurality of receiving optical elements may be combined to generate a single signal, for example, with improved signal to noise ratio compared to signal received from a single optical element. A common signal ensures increased reliability and/or keeping costs low. In some examples, the optical elements may be driven to transmit a common signal. In further examples, a set of optical elements on an antenna unit comprises one or more optical elements.

AAS provides for adaptivity and steerability, in terms of adapting the antenna radiation patterns to rapidly time-varying traffic and multi-path radio propagation conditions, compared to conventional antenna systems. This makes AAS advantageous for the present indoor scenario and, specifically, for serving manufacturing plant applications. In the present disclosure, the access network comprises both antennas (e.g. AAS) and optical elements. The optical elements provide for optical communication with the wireless devices (e.g. AGV). The optical communication is free space optical communication, i.e. line of sight transmission/receiving of modulated optical signals. Thus, optical fibers are not required for the optical communication.

The optical elements <NUM> may be optical receivers, optical transmitters or optical transceivers. Optical elements are a part of the access network and the wireless device. The optical receivers may be considered as photo-detectors, e.g. photodiodes. This enables the reception of optical signals generated by an optical transmitter on the wireless device. The optical transmitters may be considered as photo-emitters, e.g. LED transmitters. The optical transceivers may be any combination of technologies for optical transmitting and receiving.

For the example that the optical elements of the access network are optical transceivers, the optical elements enable bi-directional optical links between the antenna and the wireless device. In this example, the wireless device comprises one or more optical transceivers, rather than the merely a transmitter for one-way (uplink) communication with an optical receiver.

The set of optical elements <NUM> are associated with the radio antennas <NUM>;<NUM>. In some examples, one or more optical element <NUM> is co-located with the radio antenna elements <NUM>. In some examples, a set of a plurality of optical elements is co-located with the radio antenna elements. The network node may comprise an antenna unit, or a substrate, supporting one or more radio antenna elements and one or more optical elements. As such, the radio antenna and optical elements may be considered as integrated. In other examples, the optical elements are located on a separate unit or substrate from the radio antenna elements. The optical elements may be sufficiently close to the radio antenna elements that a particular wireless device communicating with radio antenna is in communication with a known optical element or known set of optical elements, e.g. the set of optical elements on the same antenna unit as the radio antenna elements in communication with the wireless device. The radio and optical communication is therefore integrated for communication with a same (or associated) network node.

<FIG> shows examples of an antenna unit comprising both radio antenna elements <NUM> and optical elements <NUM>. The access network comprises a plurality of antenna units of the same or different types. The radio antenna elements of the radio antenna are arranged in an array. In some examples, at least one of the optical elements is an optical receiver. The antenna unit may be considered as a network node, or a part of a network node.

In these examples, the antenna unit <NUM>;<NUM> comprises a plurality of optical elements <NUM>. The optical elements of an antenna unit may operate independently from each other and/or in the same function, i.e. providing duplication. For example, for a plurality of optical receivers, optical reception is made more robust by using increasing the number of optical receivers. One or more of the plurality of optical elements may be considered a spare, or used to receive a signal which is combined with a signal from another of the optical elements. In some examples, different ones of the plurality of optical elements receives data from different wireless devices.

The optical communication described requires a line of sight between the communicating optical elements <NUM> (e.g. the access network antenna and an optical transmitter on the wireless device). If the wireless devices (e.g. vehicle or AGV) are in motion, it can happen that an optical link is not always available, because line of sight has been temporarily lost. The radio link does not require line of sign, and so will always be present. The dropping of an optical link is not critical, the optical links are used to support the radio links when available.

The access network is configured so that the total number of optical links is relatively stable, to ensure a substantial offload of the radio layer. This provides for a greater efficiency and robustness of the entire network.

<FIG> illustrates an example arrangement used to connect a wireless device <NUM> (e.g. AGV) to an access network having a plurality of network nodes, e.g. comprising the antenna units <NUM>. The wireless device <NUM> is connected by a radio link in the downlink direction (i.e. access network to wireless device). In some examples, the radio link is a <NUM> (e.g. NR) radio link, which can provide a low-latency radio link. The uplink is provided through the optical link. The use of the optical link offloads the uplink radio resources to the optical spectrum. In some examples, the access network also provides an uplink radio link, for example, in case of loss of the optical link. In some examples, the radio link is always set up, even if the optical link is operating. A radio scheduler will manage both the radio frequency and optical resources, and is configured to determine at each point in time how many layers (e.g. radio layers, optical layer) are possible or required to transmit data.

In some examples, the optical link carries a real-time, continuous, video streaming from the wireless device to the access network (and then, for example, to cloud computation). The optical link carries the whole of the video streaming data. This requires the optical transmitter on the wireless device (e.g. AGV) and the optical receiver (e.g. on the radio antenna) to be in line-of-sight. The requirement of the line-of-sight condition is practical due to the indoor deployment of the access network, which is more controllable than an outdoor deployment, e.g. visual obstacles can be avoided more easily. In some examples, the optical link is only for uplink, and the optical elements do not provide for downlink optical communication.

The setup or tear-down of optical links can be managed as it is done for a radio channel. For example, as if the radio link and optical link are using a same allocation of "time-frequency" resource simultaneously. For example, the optical layer is realized with a simple "media conversion" of a conventional radio layer. For example, the baseband processing of the optical signal is carried out using a radio baseband processing. The baseband is then converted to an optical frequency instead of a radio frequency. Even if controlling the optical link as a radio link does not use the optical resource in an optimal way, it allows to simplify the management of the two technologies/domains (radio and optical). In this way, the radio management controls the one or more optical links.

The proposed solution allows offloading the uplink traffic in an indoor scenario over an optical link. With this technique the co-existent indoor <NUM> cellular network is lightened by offloading a large amount of data.

The optical link may be coupled with the radio link using beamforming. In some examples, the radio link uses a millimeter wavelength (mmW) radio channel. The optical uplink can benefit from tracking provided by directional beamforming of the radio link, making the offload easy to achieve.

In some examples, layers of the radio protocol stack are also used for the optical links. Additional optical links can be managed as additional carriers (or layers) to the carriers/layers already supported by the radio links.

The examples are compatible with a smooth migration from communication using only a radio link towards the described examples, as legacy systems can continue to use cellular radio links only in both uplink and downlink until the optical offload ability is installed.

For examples of the use case of the present disclosure, the uplink channel (from wireless device <NUM> to access network) requires a larger amount of data transfer than the downlink channel. For example, a continuous image/video streaming is fed from the wireless device (e.g. vehicle) to a visual navigation engine in the network (e.g. in a cloud). Latency performance is more important on the downlink channel than on the uplink channel. For example, commands to the wireless device, e.g. direction instructions should arrive at the wireless device (e.g. vehicle) from the network as soon as possible. For example, a command to the vehicle to "stop", e.g. in case of an obstacle on the path, needs to be sent with a low latency.

In some examples, data communication in the downlink direction uses only the radio frequency, when the optical channel is used for uplink communication. In this case, there is no data being transmitted in the uplink radio frequency communication. In some examples, control signalling is transmitted from the wireless device in the uplink direction when the optical channel is used for uplink communication. In some examples, the optical communication is only in the uplink direction. In this case, data is transmitted exclusively by the radio frequency link in the downlink direction, and data is transmitted exclusively by the optical link in the uplink direction. References to uplink and downlink communication may refer to data communication only, i.e. not for control signalling. In some aspects, the access network and wireless device using the radio link only for downlink communication may mean that the wireless device transmits no uplink radio communication, or the wireless device transmits only control signaling in the uplink direction (i.e. no data traffic).

<NUM> can provide with radio infrastructure, an enhanced mobile broadband (eMBB) slice plus an ultra-reliable low-latency communication (uRLLC) slice. However, the network requirements for the described examples are asymmetric in uplink and downlink, which results in a waste of radio resources. In addition, the wireless devices (e.g. vehicle) are allowed to move freely within the coverage of the indoor access network comprising a set of radio antennas, e.g. providing small cells. Every antenna on the path of the wireless device (e.g. AGV) provides the same performance in both uplink and downlink with a transparent handover.

The access network or wireless device converts the signal to be transmitted to an optical frequency as a final step prior to transmission. This optical conversion is carried out by a simple media conversion (e.g. from/to the baseband processor), and this function can be achieved at the antenna or network node without affecting higher radio layers.

In some examples, the optical link utilizes an optical physical layer, i.e. layer <NUM>. The higher layers, e.g. layer <NUM> and above are common to the radio link. In some examples, one or more layer <NUM> and/or layer <NUM> protocols used for the radio link are also used for the optical link, e.g. the Medium Access Control (MAC), Radio Link Control (RLC), packet Data Convergence Protocol (PDCP) and/or Radio Resource Control (RRC) protocol used by the NR (and other radio access technologies) radio link. In some examples, one or more layer <NUM> or <NUM> protocols are specific to the optical link, e.g. the radio protocol is not additionally used for the optical link.

Examples of the disclosure use the additional optical resources as equivalent to a set of RF carriers. The radio control for the radio link, e.g. one or more of the RLC, MAC, RRC layer, treats the optical layer as an additional RF carrier/layer.

In some aspects, the radio link and optical link share a common control plane. The control plane is that of the radio link, i.e. cellular radio access technology. In some examples, the handover function of the radio link is common to the radio and optical links, e.g. as provided by a radio controller implementing a Radio Resource Management (RRM) radio function and/or other protocols and functions. Thus, the handover of a radio link of a wireless device to a different antenna of the access network is accompanied by a corresponding handover of the optical link of the wireless link to an associated optical element. In some examples, one or more Layer <NUM> to <NUM> radio protocols are adapted to control the radio and optical links. As such, the optical link may utilize the radio protocol without substantive adaptation, utilize the radio protocol with an adaptation or (e.g. for the physical layer) use a specific optical protocol.

The access network is configured to provide for handover of the wireless device between different sets of optical elements, e.g. between different antennas/network nodes. In some examples, a node of the access network transmits control signaling to the wireless device, to control the handover (e.g. to inform the wireless device of a radio and optical node/cell identifier to use for further communication). The set of optical elements located on, or associated with, a radio antenna may be considered as providing an optical link which is associated with that radio antenna or radio cell. Such an optical link may be referred to as an "optical cell". The access network is configured to handover the optical connection to another "optical cell", i.e. another set of optical elements located on, or associated with, another radio antenna <NUM>;<NUM>. The optical handover is initiated and/or controlled by the access network. This is different to, for example, a non-cellular wireless local area network such as Wi-Fi (IEEE <NUM>), in which movement between Wi-Fi access points requires re-association and is initiated from the wireless device.

Thus, the access network of the present disclosure provides for handover of both the radio and optical links. The radio and optical links are both managed by a radio controller in the access network, e.g. in a network node. In some examples, the radio controller controls the optical link as an additional radio resource, e.g. with the same scheduling used for the radio resources. As such, optical resources are scheduled as additional radio spectrum. The protocols for allocation and control of the radio resource are (at least partially) re-used for the optical link. The use of handover is useful in industrial applications, for example to maintain a deterministic latency and performance across the whole area. The present disclosure comprises the combination of a radio cellular technology and an optical link.

Aspects of the disclosure relate to a single antenna unit comprising both optical elements <NUM> and radio antenna elements <NUM>. As such, the radio antenna (e.g. AAS) comprises integrated optical elements <NUM>. Aspects of the disclosure further relate to a common protocol stack (i.e. the cellular radio stack) for radio and optical links, e.g. down to the baseband processing. In some examples, handover between antennas is carried out for the radio link together with the optical link. Having RF and optical elements co-located in the antenna unit allows both the radio and optical links to use as much of the radio processing as possible prior to transmission. For example, having the RF and optical elements co-located, or at least adjacent or in close proximity, allows for handover of the radio and optical links together. Thus, a single handover decision by the access network provides for joint handover of both the radio and optical links at the same time and to the same target antenna unit or associated radio frequency antenna and set of optical elements.

Examples of the access network may include any "radio function split" strategy, i.e. the distribution of radio functions between the same or different nodes. For example, one or more of an antenna (antenna unit), radio unit and baseband processing unit may be in the same node (e.g. monolithic base station) or different nodes of the access network. In some examples, the optical link differs from the radio link only in the physical layer (i.e. in the "last hop" towards the wireless device).

Examples of the present disclosure increase the access network capacity, and also makes communication with the wireless device more resilient. This is a useful requirement for certain industrial applications, and not yet completely satisfied by current networks. The network may be viewed as slices, with each network slice being an isolated end-to-end network. The access network is used to deliver not only Enhanced Mobile Broadband (eMBB) slides, but for example also Ultra Reliable Low Latency Communications (URLLC) and/or Massive Machine Type Communications (mMTC) slices. All these slices compete for the same radio spectrum. By lightening the eMBB slice, though optical offload, it is possible to improve the provision of uRLLC/mMTC requirements.

The optical link or channel is managed by the access network as an additional radio resource and is managed as one or more radio layer. In some respects, the optical link is considered as an additional layer, in the same way that multiple layers are present for multiple-input and multiple-output (MIMO) radio links. This simplifies management of the optical channel and help to reduce costs. By offloading the radio links, it also helps to preserve the high performance and reliability of <NUM> without the need to exclusively dedicate radio resources, e.g. to robots and other machinery in the factory.

The optical link may be used in uplink and downlink, or only in uplink. The use of the optical link in only one direction (for example uplink that requires higher traffic) has a lower cost, since it is not necessary to have a complete transceiver on the antenna unit and on the wireless device, e.g. the optical link only needs a receiver on the antenna unit and transmitter on the wireless device (e.g. AGV). In this case, however, the downlink channel is guaranteed by the presence of the radio downlink channel. Using radio (e.g. <NUM>) for the downlink direction may be preferred as typically the downlink direction is used to send control signals to the robot/AGV. The control signals may be very latency critical (down to few milliseconds round trip time) and the <NUM> radio link can be better controlled in terms of latency. On the contrary, for the uplink direction, the dominant parameter is the high bandwidth to stream video or other data from the robot/AGV towards the cloud. So, here, an optical uplink can be beneficial.

<FIG> is a flow chart of an example of a method <NUM> in an access network for communication with a wireless device. Corresponding steps are applicable to a network node of the access network. The method comprises establishing <NUM> a cell for radio frequency communication with the wireless device. In <NUM>, the network node or access network establishes an optical link using a set of optical elements (for a network node) or a plurality of sets of optical elements (for an access network) which configured for optical communication with the wireless device. In some examples, the establishing of the optical link uses control signalling which corresponds to, or is substantially also used for, establishing radio link control. The establishing links with a plurality of sets of optical elements may refer to establishing only one link at a time for a wireless device, or establishing a plurality of links at a time for a wireless device. In some aspects, the establishing comprises setting up or reconfiguring a radio/optical link with a wireless device for a particular network node or for the access network.

In <NUM>, the network node or access network connects <NUM> the network node or access network to the wireless device with both the radio frequency communication and optical communication. The access network connects to the wireless device with the radio frequency communication at least in a downlink direction, and connects to the wireless device with the optical communication at least in an uplink direction. The step of connecting to the network node or access network may refer to transmission of data between the network node and wireless device.

The steps <NUM>,<NUM> of establishing an optical link and radio link may be considered as optional or combined with the connecting <NUM>, and the disclosure may refer merely to the transmission <NUM> of data between the network node and wireless device. In some examples, the transmission of data using the optical and radio link both use a baseband processing configured for radio communication.

<FIG> is an example of a network node <NUM>. The network node may comprises or is connected to the antenna elements and optical elements, e.g. to an antenna unit <NUM>,<NUM>. The network node <NUM> is part of the access network. The network node comprises a processor (or processing circuitry) <NUM> connected to a memory <NUM>. In some aspects, the memory <NUM> stores a computer program for execution of the method of operation of communication with the wireless device of any example. The processor <NUM>, together with the memory, is arranged to establish <NUM> a cell for radio frequency communication with the wireless device. The processor is further arranged to establish <NUM> an optical link via a set of optical elements configured for optical communication with the wireless device. In some examples, the establishing of the optical link uses control signalling which corresponds to, or is substantially also used for, establishing radio link control. In some aspects, the establishing comprises setting up or reconfiguring a radio/optical link with a wireless device for a particular network node or for the access network.

The processor <NUM> is further arranged to connect <NUM> the network node to the wireless device with both the radio frequency communication and optical communication. The access network connects to the wireless device with the radio frequency communication at least in a downlink direction, and connects to the wireless device with the optical communication at least in an uplink direction. The step of connecting to the network node or access network may refer to transmission of data between the network node and wireless device.

The operations <NUM>,<NUM> of establishing an optical link and radio link may be considered as optional or combined with the connecting <NUM>, and the disclosure may refer merely to the transmission <NUM> of data between the network node and wireless device. In some examples, the transmission of data using the optical and radio link both use a baseband processing configured for radio communication.

<FIG> is a flow chart of an example of a method <NUM> in a wireless device <NUM>. The method comprises establishing <NUM> radio frequency communication with a cell of the access network. In <NUM>, the wireless device establishes an optical link using one or more optical elements which are configured for optical communication with a network node. The establishing links may be with a plurality of sets of optical elements or a plurality of links at a time for a wireless device with the same or different network node. In some aspects, the establishing comprises setting up or reconfiguring a radio/optical link with a particular network node or for the access network.

In <NUM>, the network node or access network connects <NUM> the wireless device to the network node or access network with both the radio frequency communication and optical communication. The wireless device connects to the access network with the radio frequency communication at least in a downlink direction, and connects to the access network with the optical communication at least in an uplink direction. The step of connecting to the network node or access network may refer to transmission of data between the network node and wireless device.

The steps <NUM>,<NUM> of establishing an optical link and radio link may be considered as optional or combined with the connecting <NUM>, and the disclosure may refer merely to the transmission <NUM> of data between the network node and wireless device.

<FIG> is an example of a wireless device <NUM>, e.g. corresponding to AGV <NUM>. The wireless device <NUM> may comprise or be connected to antenna elements and optical elements to connect to a network node as part of the access network. The wireless device comprises a processor <NUM> (or processing circuitry) connected to a memory. In some aspects, the memory <NUM> stores a computer program for execution of the method of operation of communication with the wireless device of any example. The processor, together with the memory, is arranged to establish radio frequency communication with a cell of the access network.

The processor is further arranged to establish <NUM> an optical link using one or more optical elements which are configured for optical communication with the network node. The establishing links may be with a plurality of sets of optical elements or a plurality of links at a time for a wireless device with the same or different network node. In some aspects, the establishing comprises setting up or reconfiguring a radio/optical link with a particular network node or for the access network.

In some examples, the establishing of the optical link uses control signalling which corresponds to, or is substantially also used for, establishing radio link control. In some aspects, the establishing comprises receiving and implementing control signalling setting up or reconfiguring a radio/optical link for a particular network node or for the access network.

The processor <NUM> is further arranged to connect <NUM> the wireless device to the network node or access network with both the radio frequency communication and optical communication. The wireless device connects to the access network with the radio frequency communication at least in a downlink direction, and connects to the access network with the optical communication at least in an uplink direction. The step of connecting to the network node or access network may refer to transmission of data between the network node and wireless device. In some examples, the transmission of data using the optical and radio link both use a baseband processing configured for radio communication.

It should be noted that the above-mentioned examples illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative examples without departing from the scope of the appended statements. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim, "a" or "an" does not exclude a plurality, and a single processor or other unit may fulfil the functions of several units recited in the statements below. Where the terms, "first", "second" etc. are used they are to be understood merely as labels for the convenient identification of a particular feature. In particular, they are not to be interpreted as describing the first or the second feature of a plurality of such features (i.e. the first or second of such features to occur in time or space) unless explicitly stated otherwise. Steps in the methods disclosed herein may be carried out in any order unless expressly otherwise stated. Any reference signs in the statements shall not be construed so as to limit their scope.

Although the subject matter described herein may be implemented in any appropriate type of system using any suitable components, the embodiments disclosed herein are described in relation to a wireless network, such as the example wireless network illustrated in <FIG>. For simplicity, the wireless network of <FIG> depicts a network <NUM>, network nodes <NUM>,960b, and wireless devices <NUM>,910b, and 910c, which may correspond to the network node and wireless device described in other embodiments. The network nodes <NUM>,960b may include or be connected to the antenna units <NUM>,<NUM> of any example. The network <NUM> may correspond to the access network comprising a plurality of the antenna units <NUM>,<NUM>, or separate radio and optical antennas, supporting both radio and optical links. Aspects of the disclosure may relate to the access network or a network node of the access network, or the wireless device.

In practice, a wireless network may further include any additional elements suitable to support communication between wireless devices or between a wireless device and another communication device, such as a landline telephone, a service provider, or any other network node or end device. Of the illustrated components, network node <NUM> and wireless device <NUM> are depicted with additional detail. The wireless network may provide communication and other types of services to one or more wireless devices to facilitate the wireless devices' access to and/or use of the services provided by, or via, the wireless network.

Thus, particular embodiments of the wireless network may implement communication standards, such as Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), Narrowband Internet of Things (NB-loT), and/or other suitable <NUM>, <NUM>, <NUM>, or <NUM> standards; wireless local area network (WLAN) standards, such as the IEEE <NUM> standards; and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave and/or ZigBee standards.

Network node <NUM> and wireless device <NUM> comprise various components described in more detail below.

The processing circuitry <NUM> may further include optical transceiver circuitry <NUM>, which may be separate or combined with the RF transceiver circuitry. The processing circuitry <NUM>, for example including baseband processing circuitry <NUM>, may be configured to handle both RF and optical communication.

Interface <NUM> is used in the wired or wireless communication of signalling and/or data between network node <NUM>, network <NUM>, and/or wireless devices <NUM>. Radio front end circuitry <NUM> may receive digital data that is to be sent out to other network nodes or wireless devices via a wireless connection.

In some examples, the optical transceiver circuitry is connected to the optical element <NUM> without passing through the interface <NUM> or radio specific front end circuitry.

The antenna <NUM> may further comprise optical elements (e.g. as described above) for sending and/or receiving optical communications.

The antenna <NUM> may comprise one or more optical element as described in any example. The wireless device <NUM> may include multiple sets of one or more of the illustrated components for different wireless technologies supported by wireless device <NUM>, such as, for example, GSM, WCDMA, LTE, NR, WiFi, WiMAX, NB-loT, or Bluetooth wireless technologies, just to mention a few. These wireless technologies may be integrated into the same or different chips or set of chips as other components within wireless device <NUM>.

In certain alternative embodiments, antenna <NUM> may be separate from wireless device <NUM> and be connectable to wireless device <NUM> through an interface or port. Antenna <NUM>, interface <NUM>, and/or processing circuitry <NUM> may be configured to perform any receiving or transmitting operations (including radio and optical communication) described herein as being performed by a wireless device. Any information, data and/or signals may be received from a network node and/or another wireless device.

In some embodiments, wireless device <NUM> may not include separate radio front end circuitry <NUM>; rather, processing circuitry <NUM> may comprise radio front end circuitry and may be connected to antenna <NUM>. Radio front end circuitry <NUM> may receive digital data that is to be sent out to other network nodes or wireless devices via a wireless connection. The antenna <NUM> may further comprise optical elements (e.g. as described above) for sending and/or receiving optical communications. In some examples, the optical transceiver circuitry is connected to the optical element without passing through the interface <NUM> or radio specific front end circuitry.

Processing circuitry <NUM> may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software, and/or encoded logic operable to provide, either alone or in conjunction with other wireless device <NUM> components, such as device readable medium <NUM>, wireless device <NUM> functionality.

In certain embodiments processing circuitry <NUM> of wireless device <NUM> may comprise a SOC. The processing circuitry <NUM> further comprises optical transceiver circuitry <NUM> for the optical element(s). The optical transceiver circuitry <NUM> may be integrated with or separate to the RF transceiver circuitry. The optical transceiver circuitry <NUM> may connect to the optical element(s) <NUM> of the antenna unit without passing though the radio front end circuitry.

In certain embodiments, some or all of the functionality described herein as being performed by a wireless device may be provided by processing circuitry <NUM> executing instructions stored on device readable medium <NUM>, which in certain embodiments may be a computer-readable storage medium. The benefits provided by such functionality are not limited to processing circuitry <NUM> alone or to other components of wireless device <NUM> but are enjoyed by wireless device <NUM> as a whole, and/or by end users and the wireless network generally.

Processing circuitry <NUM> may be configured to perform any determining, calculating, or similar operations (e.g., certain obtaining operations) described herein as being performed by a wireless device. These operations, as performed by processing circuitry <NUM>, may include processing information obtained by processing circuitry <NUM> by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored by wireless device <NUM>, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination.

Optionally, user interface equipment <NUM> may provide components that allow for a human user to interact with wireless device <NUM>. Such interaction may be of many forms, such as visual, audial, tactile, etc. User interface equipment <NUM> may be operable to produce output to the user and to allow the user to provide input to wireless device <NUM>. The type of interaction may vary depending on the type of user interface equipment <NUM> installed in wireless device <NUM>. For example, if wireless device <NUM> is a smart phone, the interaction may be via a touch screen; if wireless device <NUM> is a smart meter, the interaction may be through a screen that provides usage (e.g., the number of gallons used) or a speaker that provides an audible alert (e.g., if smoke is detected). User interface equipment <NUM> is configured to allow input of information into wireless device <NUM>, and is connected to processing circuitry <NUM> to allow processing circuitry <NUM> to process the input information. User interface equipment <NUM> is also configured to allow output of information from wireless device <NUM>, and to allow processing circuitry <NUM> to output information from wireless device <NUM>. Using one or more input and output interfaces, devices, and circuits, of user interface equipment <NUM>, wireless device <NUM> may communicate with end users and/or the wireless network, and allow them to benefit from the functionality described herein.

Auxiliary equipment <NUM> is operable to provide more specific functionality which may not be generally performed by wireless devices.

wireless device <NUM> may further comprise power circuitry <NUM> for delivering power from power source <NUM> to the various parts of wireless device <NUM> which need power from power source <NUM> to carry out any functionality described or indicated herein.

Power circuitry <NUM> may additionally or alternatively be operable to receive power from an external power source; in which case wireless device <NUM> may be connectable to the external power source (such as an electricity outlet) via input circuitry or an interface such as an electrical power cable. Power circuitry <NUM> may perform any formatting, converting, or other modification to the power from power source <NUM> to make the power suitable for the respective components of wireless device <NUM> to which power is supplied.

In some examples, one or more parts of the wireless device and network node are shared by the radio and optical links. For example, the optical and radio links may use a common baseband circuitry or the wireless device and network node use the radio baseband processing for optical communication. The processing circuitry may be configured to provide a common baseband processing for the optical and radio links. In some aspects, the baseband processing used for the optical link is the same as a radio baseband processing. As such, the baseband signal generated/received for the optical signal is the same as that for a radio signal. In some aspects, the Layer <NUM> and high layers are common for the radio and optical links. The common baseband circuitry allows the optical link to be controlled as a part of the radio link, e.g. as another carrier or radio layer. For example, the optical link uses one or more of a radio frame/subframe structure, time and frequency configuration of symbols, re-transmission (e.g. HARQ), allocation of data and/or control symbols, etc, which is the same as for the radio technology used for the radio link. In some aspects, the optical link is configured to have a bandwidth which is supported by the radio link. With a common baseband processing, the wireless device or network node generates baseband data for transmission which could be transmitted on either a radio or an optical link. When an optical link is available, the optical transceiver circuitry converts the baseband signal to an optical frequency. As such, the only difference between the radio link and optical link is in the transmission frequency, and not in the format of the data being carried. This allows control of the optical link, e.g. including handover, to be carried out by the radio technology (e.g. NR). Although the wireless device and network node are primarily described for radio communication, the wireless device and network node also comprise shared or separate elements and circuitry to provide for optical communication.

<FIG> illustrates one embodiment of a wireless device (UE) in accordance with various aspects described herein. UE <NUM> may be any UE identified by the 3rd Generation Partnership Project (3GPP), including a NB-loT UE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE. UE <NUM>, as illustrated in <FIG>, is one example of a wireless device configured for communication in accordance with one or more communication standards promulgated by the 3rd Generation Partnership Project (3GPP), such as 3GPP's GSM, UMTS, LTE, and/or <NUM> standards. As mentioned previously, the term wireless device and UE may be used interchangeable. Accordingly, although <FIG> is a UE, the components discussed herein are equally applicable to a wireless device, and vice-versa.

In <FIG>, UE <NUM> includes processing circuitry <NUM> that is operatively coupled to input/output interface <NUM>, radio frequency (RF) and optical interface <NUM>, network connection interface <NUM>, memory <NUM> including random access memory (RAM) <NUM>, read-only memory (ROM) <NUM>, and storage medium <NUM> or the like, communication subsystem <NUM>, power source <NUM>, and/or any other component, or any combination thereof. The radio frequency (RF) and optical interface <NUM> may comprise one or a plurality of elements or units.

In <FIG>, RF and optical interface <NUM> may be configured to provide a communication interface to RF components such as a transmitter, a receiver, and an antenna. The RF and optical interface <NUM> may be further configured to provide a communication interface to optical components such as a transmitter, a receiver. Network connection interface <NUM> may be configured to provide a communication interface to network 1043a. Network 1043a may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network 1043a may comprise a Wi-Fi network.

In <FIG>, processing circuitry <NUM> may be configured to communicate with network 1043b using communication subsystem <NUM>. Network 1043a and network 1043b may be the same network or networks or different network or networks. Communication subsystem <NUM> may be configured to include one or more transceivers used to communicate with network 1043b. For example, communication subsystem <NUM> may be configured to include one or more transceivers used to communicate with one or more remote transceivers of another device capable of wireless communication such as another wireless device, UE, or base station of a radio access network (RAN) according to one or more communication protocols, such as IEEE <NUM>, CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like, and an optical link. Each transceiver may include transmitter <NUM> and/or receiver <NUM> to implement transmitter or receiver functionality, respectively, appropriate to the RAN links (e.g., frequency allocations and the like) and optical link.

For example, communication subsystem <NUM> may include cellular communication, optical communication, Wi-Fi communication, Bluetooth communication, and GPS communication. Network 1043b may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network 1043b may be a cellular network, a Wi-Fi network, and/or a near-field network.

Virtualization environment <NUM>, comprises general-purpose or special-purpose network hardware devices <NUM> comprising a set of one or more processors or processing circuitry <NUM>, which may be commercial off-the-shelf (COTS) processors, dedicated Application Specific integrated Circuits (ASICs), or any other type of processing circuitry including digital or analog hardware components or special purpose processors.

The transmitters <NUM> may also include an optical transmitter and/or receiver.

<FIG> illustrates a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments. In particular, with reference to <FIG>, in accordance with an embodiment, a communication system includes telecommunication network <NUM>, such as a 3GPP-type cellular network, which comprises access network <NUM>, such as a radio access network, and core network <NUM>. Access network <NUM> comprises a plurality of base stations 1212a, 1212b, 1212c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 1213a, 1213b, 1213c. Each base station 1212a, 1212b, 1212c is connectable to core network <NUM> over a wired or wireless connection <NUM>. A first UE <NUM> located in coverage area 1213c is configured to wirelessly connect to, or be paged by, the corresponding base station 1212c. A second UE <NUM> in coverage area 1213a is wirelessly connectable to the corresponding base station 1212a.

<FIG> illustrates host computer communicating via a base station with a user equipment over a partially wireless connection in accordance with some embodiments In communication system <NUM>, host computer <NUM> comprises hardware <NUM> including communication interface <NUM> configured to set up and maintain a wired or wireless connection with an interface of a different communication device of communication system <NUM>.

It is noted that host computer <NUM>, base station <NUM> and UE <NUM> illustrated in <FIG> may be similar or identical to host computer <NUM>, one of base stations 1212a, 1212b, 1212c and one of UEs <NUM>, <NUM> of <FIG>, respectively.

Wireless connection <NUM> between UE <NUM> and base station <NUM> is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE <NUM> using OTT connection <NUM>, in which wireless connection <NUM> forms the last segment. More precisely, the teachings of these embodiments may eliminate an ambiguity in network signaling and thereby provide benefits such as improved reliability and efficiency, and avoiding wasting computational and air interface resources on error recovery.

Other objectives, features and advantages of the enclosed embodiments will be apparent from the description.

Claim 1:
An access network for communication with a wireless device (<NUM>);
the access network comprising:
a plurality of antennas each configured to provide a cell for radio frequency communication with the wireless device
a plurality of sets of optical elements (<NUM>) configured for optical communication with the wireless device (<NUM>);
wherein the access network comprises a processor and a memory, said memory containing instructions executable by said processor whereby said apparatus is operative to:
connect to the wireless device with both the radio frequency communication and optical communication, and connect to the wireless device with the radio frequency communication at least in a downlink direction, and connect to the wireless device with the optical communication at least in an uplink direction, and
wherein the access network is configured to handover the wireless device between the radio frequency cells and between the sets of optical elements, wherein the handover of the wireless device between the sets of optical elements is controlled by the radio frequency communication.