BACKGROUND

Field

The present disclosure relates to methods of operating an unmanned aerial vehicle, UAV to transmit and/or to receive wireless communications signals and UAVs. The present disclosure claims the Paris convention priority of European patent application EP22165614.3 filed on 30 March 2022, the contents of which are incorporated herein by reference in their entirety.

Description of Related Art

The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present invention.

Third and fourth generation mobile telecommunication systems, such as those based on the 3GPP defined UMTS and Long Term Evolution (LTE) architecture, are able to support more sophisticated services than simple voice and messaging services offered by previous generations of mobile telecommunication systems. For example, with the improved radio interface and enhanced data rates provided by LTE systems, a user is able to enjoy high data rate applications such as mobile video streaming and mobile video conferencing that would previously only have been available via a fixed line data connection. The demand to deploy such networks is therefore strong and the coverage area of these networks, i.e. geographic locations where access to the networks is possible, may be expected to increase ever more rapidly.

Future wireless communications networks will be expected to routinely and efficiently support communications with a wider range of devices associated with a wider range of data traffic profiles and types than current systems are optimised to support. For example, it is expected that future wireless communications networks will be expected to efficiently support communications with devices including reduced complexity devices, machine type communication devices, high resolution video displays, virtual reality headsets and so on. Some of these different types of devices may be deployed in very large numbers, for example low complexity devices for supporting the “The Internet of Things”, and may typically be associated with the transmissions of relatively small amounts of data with relatively high latency tolerance. Other types of devices may generate or receive categories of data associated with differing quality of service requirements - some low bitrate data may be associated with, for example, a low latency and near-zero packet loss requirement; other data, having a higher bitrate, may be more tolerant of latency and/or packet loss.

In view of this there is expected to be a desire for future wireless communications networks, for example those which may be referred to as 5G or new radio (NR) system / new radio access technology (RAT) systems, as well as future iterations / releases of existing systems, to efficiently support connectivity for a wide range of devices associated with different applications and different characteristic data traffic profiles and data transfer requirements, for example in terms of latency and / or reliability targets. See, for example, the 3GPP document RP-160671, “New SID Proposal: Study on New Radio Access Technology,” NTT DOCOMO, RAN#71 [1], The introduction of new radio access technology (RAT) systems / networks gives rise to new challenges for providing efficient operation for devices operating in new RAT networks, including devices able to operate in both new RAT networks (e.g. a 3GPP 5G network) and currently deployed RAT networks (e.g. a 3 GPP 4G network).

In order to improve coverage and provide for different types of mobile user equipment there is a desire for communications devices (user equipment) to be mounted on of form part of an Unmanned Aerial Vehicle (UAV), such as a drone of the like or indeed the UAV may carry an infrastructure equipment of a wireless communications network. As such there is a need to improve a use of UAVs for wireless communications.

SUMMARY

The present disclosure can help address or mitigate at least some of the issues discussed above.

Embodiments of the present technique can provide a method of operating an Unmanned Aerial Vehicle, UAV. The method comprises transmitting signals to a wireless communications network or to a communications device configured to communicate via the wireless communications network, the signals being transmitted via a wireless access interface between the UAV and the wireless communications network or between the UAV and the communications device, or receiving signals from the wireless communications network or from a communications device configured to communicate via the wireless communications network, the signals being received via the wireless access interface between the UAV and the wireless communications network or between the UAV and the communications device, and transmitting, by the UAV, a UAV identification, wherein the UAV identification comprises: an indication of a serial number assigned to the UAV or a session identifier assigned to the UAV by a remote identification Unmanned Aircraft System, UAS, service supplier; an indication of a time when the UAV identification is transmitted; and an indication of an emergency status of the UAV.

One particular area where new approaches may be helpful is in relation to NR support for UAV identification. UAVs, typically although not always, small and remotely-operated vehicles provide many advantages over traditional vehicles, including manoeuvrability, efficiency, compact size, and cost. However, as the number of UAVs in operation, and the problems which UAVs are deployed to address, grows, there is increased need to co-ordinate the locations and identities of the UAVs operating in a particular area.

In view of the above, there is a desire for new approaches to co-ordinate and transmit the identities and locations of UAVs via an interface.

Respective aspects and features of the present disclosure are defined in the appended claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary, but are not restrictive, of the present technology. The described embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein like reference numerals designate identical or corresponding parts throughout the several views, and wherein: Figure 1 schematically represents some aspects of a LTE-type wireless telecommunication network which may be configured to operate in accordance with certain embodiments of the present disclosure;

Figure 2 schematically represents some aspects of a new radio access technology (RAT) wireless communications network which may be configured to operate in accordance with certain embodiments of the present disclosure;

Figure 3 is a schematic block diagram of an example infrastructure equipment and communications device which may be configured in accordance with example embodiments;

Figure 4 schematically represents some aspects of the present disclosure, wherein a plurality of user equipment and an infrastructure equipment are depicted, in addition to the communication links between them in accordance with certain example embodiments;

Figure 5 is a schematic block diagram of a protocol level stack within two user equipment, and the interface between them, in accordance with example embodiments of the present disclosure;

Figure 6 is a graphical representation of a sidelink UAV identification request, in accordance with some embodiments of the present disclosure;

Figure 7 is a schematic block diagram of a system architecture enabling the processing of a UAV identification to be performed by a central body, in accordance with certain embodiments of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Figure 1 provides a schematic diagram illustrating some basic functionality of a wireless communications network / system 100 operating generally in accordance with LTE principles (also referred to as 4G), but which may also support other radio access technologies, and which may implement embodiments of the disclosure as described herein. Various elements of Figure 1 and certain aspects of their respective modes of operation are well-known and defined in the relevant standards administered by the 3GPP (RTM) body, and also described in many books on the subject, for example, Holma H. and Toskala A [2] . It will be appreciated that operational aspects of the wireless communications networks discussed herein which are not specifically described (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be implemented in accordance with any known techniques, for example according to the relevant standards and known proposed modifications and additions to the relevant standards.

The network 100 includes a plurality of base stations 101 connected to a core network 102. Each base station provides a coverage area 103 (i.e. a cell) within which data can be communicated to and from terminal devices 104. Although each base station 101 is shown in Figure 1 as a single entity, the skilled person will appreciate that some of the functions of the base station may be carried out by disparate, inter-connected elements, such as antennas (or antennae), remote radio heads, amplifiers, etc. Collectively, one or more base stations may form a radio access network.

Data is transmitted from base stations 101 to terminal devices 104 within their respective coverage areas 103 via a radio downlink (DL). Data is transmitted from terminal devices 104 to the base stations 101 via a radio uplink (UL). The core network 102 routes data to and from the terminal devices 104 via the respective base stations 101 and provides functions such as authentication, mobility management, charging and so on. Terminal devices may also be referred to as mobile stations, user equipment (UE), Wireless Transmit/Receive Unit (WTRU), user terminal, mobile radio, communications device, and so forth. Services provided by the core network 102 may include connectivity to the internet or to external telephony services. The core network 102 may further track the location of the terminal devices 104 so that it can efficiently contact (i.e. page) the terminal devices 104 for transmitting downlink data towards the terminal devices 104.

Base stations, which are an example of network infrastructure equipment / network access node, may also be referred to as transceiver stations / nodeBs / e-nodeBs, g-nodeBs and so forth. In this regard different terminology is often associated with different generations of wireless communications systems for elements providing broadly comparable functionality. However, certain embodiments of the disclosure may be equally implemented in different generations of wireless communications systems, and for simplicity particular terminology may be used regardless of the underlying network architecture. That is to say, the use of a specific term in relation to certain example implementations is not intended to indicate these implementations are limited to a certain generation of network that may be most associated with that particular terminology.

Figure 2 is a schematic diagram illustrating a network architecture for a new RAT (NR), also referred to as 5G, wireless communications network / system 200 based on previously proposed approaches which may also be adapted to provide functionality in accordance with embodiments of the disclosure described herein. The NR radio access system employs Orthogonal Frequency Division Multiple Access (OFDMA), where different users are scheduled in different subsets of sub-carriers simultaneously. However, OFDMA requires tight synchronisation in the uplink transmissions in order to achieve orthogonality of transmissions from different users. In essence, the uplink transmissions from all users must arrive at the same time (i.e. they must be synchronised) at the gNB receiver. A UE that is far from the gNB must therefore transmit earlier than a UE closer to the gNB, due to different RF propagation delays. In NR, timing advance commands are applied to control the uplink transmission timing for individual UEs, mainly for Physical Uplink Shared Channels (PUSCHs), Physical Uplink Control Channels (PUCCHs) and Sounding Reference Signals (SRS). The timing advance usually comprises twice the one-way propagation delay between the UE and gNB, thus representing both downlink and uplink delays.

In Figure 2 a plurality of transmission and reception points (TRPs) 210 are connected to distributed control units (DUs) 241, 242 by a connection interface represented as a line 216. Each of the TRPs 210 is arranged to transmit and receive signals via a wireless access interface (i.e. a radio interface for wireless access) within a radio frequency bandwidth available to the wireless communications network. Thus, within a range for performing radio communications via the wireless access interface, each of the TRPs 210, forms a cell 212 of the wireless communications network as represented by a circle 212. As such, wireless communications devices 214 which are within a radio communications range provided by the cells 212 can transmit and receive signals to and from the TRPs 210 via the wireless access interface. Each of the distributed units 241, 242 are connected to a central unit (CU) 240 (which may be referred to as a controlling node) via an interface 246. The central unit 240 is then connected to the core network 220 which may contain all other functions required to transmit data for communicating to and from the wireless communications devices and the core network 220 may be connected to other networks 230.

The elements of the wireless access network shown in Figure 2 may operate in a similar way to corresponding elements of an LTE network as described with regard to the example of Figure 1. It will be appreciated that operational aspects of the telecommunications network represented in Figure 2, and of other networks discussed herein in accordance with embodiments of the disclosure, which are not specifically described (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be implemented in accordance with any known techniques, for example according to currently used approaches for implementing such operational aspects of wireless telecommunications systems, e.g. in accordance with the relevant standards.

The TRPs 210 of Figure 2 may in part have a corresponding functionality to a base station or eNodeB of an LTE network (such as base station 101 of Figure 1). Similarly, the communications devices 214 may have a functionality corresponding to the UE devices 104 of Figure 1 known for operation with an LTE network. It will be appreciated therefore that operational aspects of a new RAT network (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be different to those known from LTE or other known mobile telecommunications standards. However, it will also be appreciated that each of the core network component, base stations and communications devices of a new RAT network will be functionally similar to, respectively, the core network component, base stations and communications devices of an LTE wireless communications network.

In terms of broad top-level functionality, the core network 220 connected to the new RAT telecommunications system represented in Figure 2 may be broadly considered to correspond with the core network 102 represented in Figure 1, and the respective central units 240 and their associated distributed units / TRPs 210 may be broadly considered to provide functionality corresponding to the base stations 101 of Figure 1. The term network infrastructure equipment / access node may be used to encompass these elements and more conventional base station type elements of wireless telecommunications systems. Depending on the application at hand the responsibility for scheduling transmissions which are scheduled on the radio interface between the respective distributed units and the communications devices may he with the controlling node / central unit and / or the distributed units / TRPs. A communications device 214 is represented in Figure 2 within the coverage area of a communication cell 212. This communications device 214 may thus exchange signalling with the first central unit 240 in the communication cell 212 via one of the distributed units / TRPs 210 associated with the communication cell 212.

It will further be appreciated that Figure 2 represents merely one example of a proposed architecture for a new RAT communications system in which approaches in accordance with the principles described herein may be adopted, and the functionality disclosed herein may also be applied in respect of wireless communications systems having different architectures.

Thus certain embodiments of the disclosure as discussed herein may be implemented in wireless telecommunication systems / networks according to various different architectures, such as the example architectures shown in Figures 1 and 2. It will thus be appreciated the specific wireless communications architecture in any given implementation is not of primary significance to the principles described herein. In this regard, certain embodiments of the disclosure may be described generally in the context of communications between network infrastructure equipment / access nodes and a terminal device, wherein the specific nature of the network infrastructure equipment / access node and the terminal device will depend on the network infrastructure for the implementation at hand. For example, in some scenarios the network infrastructure equipment / access node may comprise a base station, such as an LTE-type base station 101 as shown in Figure 1 which is adapted to provide functionality in accordance with the principles described herein, and in other examples the network infrastructure equipment / access node may comprise a control unit / controlling node 240 and / or a TRP 210 of the kind shown in Figure 2 which is adapted to provide functionality in accordance with the principles described herein.

As already noted, mobile communications networks such as the network 100 shown in Figure 1 and the network 200 shown in Figure 2 may be expected to support a wide range of services having different requirements, for example in terms of data rate, latency and / or reliability targets for the different services, possibly associated with a single terminal device. One example service currently considered to be of interest for next generation wireless communication systems includes so-called Ultra Reliable and Low Latency Communications (URLLC).

URLLC services may be typically characterised as low latency services, for example aiming to transmit relatively small amounts of data through the radio network with a 1 ms packet transit time i.e. so that each piece of URLLC data needs to be scheduled and transmitted across the physical layer in a time that is shorter than 1 millisecond, in order to permit and end-to-end latency between a terminal device’s application layer and the edge of the wireless communication network operator’s packet network of no more than 1 millisecond). URLLC services typically may require high reliability of data transmission, for example with a 99.999% reliability target. URLLC services may, for example, be applicable for safety-relevant communications, for example, communications relating to autonomous vehicle (driverless car) applications. In addition, systems may be expected to support further enhancements related to Industrial Internet of Things (IIoT) in order to support services with new requirements of high availability, high reliability, low latency, and in some cases, high-accuracy positioning.

A more detailed illustration of a first UE (or WTRU) 270a, a second UE 270b and an example network infrastructure equipment 272, which may be thought of as a gNB 101 or a combination of a central unit / controlling node 240 with a distributed unit 241, 242 and TRP 212, is presented in Figure 3. As shown in Figure 3, the UE 270a is shown to transmit uplink data to the infrastructure equipment 272 via grant free resources of a wireless access interface as illustrated generally by an arrow 274. The UE 270a is shown to receive downlink data transmitted by the infrastructure equipment 272 via resources of the wireless access interface as illustrated generally by an arrow 288. As with Figures 1 and 2, the infrastructure equipment 272 is connected to a core network 276 via an interface 278 to a controller 280 of the infrastructure equipment 272. The infrastructure equipment 272 includes a receiver 282 connected to an antenna 284 and a transmitter 286 connected to the antenna 284. Correspondingly, the UE 270 includes a controller 290 connected to a receiver 292 which receives signals from an antenna 294 and a transmitter 296 also connected to the antenna 294.

The controller 280 is configured to control the infrastructure equipment 272 and may comprise processor circuitry which may in turn comprise various sub-units / sub-circuits for providing functionality as explained further herein. These sub-units may be implemented as discrete hardware elements or as appropriately configured functions of the processor circuitry. Thus the controller 280 may comprise circuitry which is suitably configured / programmed to provide the desired functionality using conventional programming / configuration techniques for equipment in wireless telecommunications systems. The transmitter 286 and the receiver 282 may comprise signal processing and radio frequency filters, amplifiers and circuitry in accordance with conventional arrangements. The transmitter 286, the receiver 282 and the controller 280 are schematically shown in Figure 3 as separate elements for ease of representation. However, it will be appreciated that the functionality of these elements can be provided in various different ways, for example using one or more suitably programmed programmable computer(s), or one or more suitably configured application-specific integrated circuit(s) / circuitry / chip(s) / chipset(s). As will be appreciated the infrastructure equipment 272 will in general comprise various other elements associated with its operating functionality.

Correspondingly, the controller 290 of the UE 270a is configured to control the transmitter 296 and the receiver 292 and may comprise processor circuitry which may in turn comprise various sub-units / sub-circuits for providing functionality as explained further herein. These sub-units may be implemented as discrete hardware elements or as appropriately configured functions of the processor circuitry. Thus the controller 290 may comprise circuitry which is suitably configured / programmed to provide the desired functionality using conventional programming / configuration techniques for equipment in wireless telecommunications systems. Likewise, the transmitter 296 and the receiver 292 may comprise signal processing and radio frequency filters, amplifiers and circuitry in accordance with conventional arrangements. The transmitter 296, receiver 292 and controller 290 are schematically shown in Figure 3 as separate elements for ease of representation. However, it will be appreciated that the functionality of these elements can be provided in various different ways, for example using one or more suitably programmed programmable computer(s), or one or more suitably configured application-specific integrated circuit(s) / circuitry / chip(s) / chipset(s). As will be appreciated the communications device 270a will in general comprise various other elements associated with its operating functionality, for example a power source, user interface, and so forth, but these are not shown in Figure 3 in the interests of simplicity.

The example shown in Figure 3 also includes the second UE 270b, which has corresponding parts to the first UE 270a and so the description will not be repeated. As explained below example embodiments can relate to an arrangement in which a UE forms a direct communication with another UE in order to transmit and receive data via a wireless communications network. According to 3GPP wireless communications standards, such as 5G/NR an interface between the first UE 270a and the second UE 270b is known as PC5. As will be explained, a process of activating a PC5 interface includes transmission of a discovery message.

V2X

As the skilled person would be aware, provision was made initially within 3GPP Rel-14 for Vehicle- to-Everything communications, V2X, (where X can stand for any object capable of communicating with the vehicle), and built upon in subsequent releases to develop infrastructure to allow low end-to- end latency for communication with a very high reliability. A key difference between the communication this has enabled and that which has preceded it is the ability for transmission directly between the UEs/WTRUs themselves, and not via a base station, gNB, eNB or other such infrastructure equipment. This is explained further in Figure 4, which is provided as an example.

Figure 4, as an example, depicts two UEs, 270a and 270b, and an infrastructure equipment denoted 272, in keeping Figures 1, 2 and 3. Downlink / uplink communications between the respective UEs 270a, 270b and the infrastructure equipment 272 are depicted by the arrows 401 and 402, with the downlink in each case originating at the infrastructure equipment 272 and terminating at the UE, whilst the uplink originates at the UE and terminates at the infrastructure equipment. For simplicity, further elements of the network are not represented, although the infrastructure equipment may be connected to further parts of the network, such as a core network 102, 220, and it would be appreciated that the network in reality might support many infrastructure equipment connected to many UEs. There is also depicted, in addition to the uplink / downlink communications links, a sidelink communication link 403 that connects the two UEs directly. That is, in one direction, the sidelink communication link originates at a first UE 270a and terminates at a second UE 270b, and vice versa in the other direction. An example communication between two UEs may proceed in the following fashion. The message data is collected / generated in 270a, and necessary headers are added to the message data by the various PDCP, MAC, PHY layers and such, before the message is transmitted via a wireless interface along the connection 401 between the UE and the infrastructure equipment 272. The message is received at the infrastructure equipment 272, where it may be received in constituent packets, and be placed in a transmission buffer until the whole of the transmission is received. Once the infrastructure equipment has received all of the data packets corresponding to the message, it decodes the header of the message to determine the destination of the message. On determining that the message is intended for the second UE, 270b, the infrastructure equipment then sends the message to the second UE 270b, where it may again be received, placed in a transmission buffer until all of the relevant packets are received, decoded from the transmission buffer after the relevant headers are removed and the data is passed up the protocol stack. Only then do the higher layers of the second UE 270b receive the data from the first UE 270a.

There are significant issues with the above procedure, notably the transmission time for two transmissions (data to be transmitted along both 401 and 402 before reaching its destination), the increased chance of any errors in the communication arising from a greater number of transmissions, the use of two buffers in the reception of the data packets, and so on.

A potential way to address the above-identified problems is to send a transmission directly between the UEs, again using the air interface but now utilising the connection 403. This will require in principle fewer stages, and since there is only one transmission, and therefore fewer opportunities for the corruption of data, poor reception of data packets, etc it may provide a greater quality of communication. A significant benefit, particularly in the light of the above developments to support URLLC and other 5G and later release technologies, is that in moving from a scenario in which a plurality of transmissions are required to a scenario where only a single transmission is required, the latency of the communication as a whole is reduced. This is an example of a sidelink communication link. Furthermore, whilst the current example includes only two UEs, it would be apparent that in other examples each UE may maintain more than one sidelink connection with another UE, and there may be more than one infrastructure equipment configured to connect to the UEs as appropriate.

An example of a sidelink communication connection is found in Figure 5, which will now be explained. Figure 5 shows various Access Stratum, AS, protocol stack levels found within a UE, as a skilled person would be familiar with, including the Radio Resource Connection, RRC, Packet Data Convergence Protocol, PDCP, Radio Link Control, RLC, Medium Access Control, MAC, and Physical layer, PHY. The protocol stack levels send data to one another, and the data for a particular protocol stack level is only acted on within that layer. In this way it can be represented that the layers “talk” only to one another at the same level i.e. the RRC of UE A “talks” to the RRC of UE B, likewise the PDCP and all the way down to the physical layer. This transmission is performed via the PC5 interface, which is an interface between the two UEs. There are other features that the PC5 interface possesses, which have not been described herein for the sake of brevity.

The PC5 link, and sidelink communications as a whole, may be employed by V2X communications more generally. As discussed above, the requirements of low latency and high reliability are particularly stringent in applications such as V2X where there may be changing conditions such as weather conditions, temperature, atmospheric pressure changes etc which may influence the communications transmission, there may be a high relative velocity for the two communicating devices, causing a need for efficient communication and identification, and the negative consequences of an error may be higher than in other areas where NR is implemented. For example, a V2X error might be a factor in causing a driverless vehicle-human operated vehicle traffic collision, where other scenarios might result in slow communication resulting in a delay in presenting data to a user. One particular embodiment of this relates to Unmanned Aerial Vehicles UAVs, or Unmanned Aircraft Systems UASs.

Regulatory Requirement

According to Federal Aviation Authority, FAA, documents, it will be a requirement for Unmanned Aircraft Systems, UASs, whilst operating in the United States airspace, to enable remote identification of the UAS. On a practical level, this might look like transmitting a number of elements in a remote identification message:

• The identity of the UAS consisting of one or more of the following:

1. The serial number assigned to the unmanned aircraft system by the producer of the unmanned aircraft system, or

2. The Session Identification, ID, assigned by a Remote ID UAS Service Supplier, USS

• An indication of the latitude and longitude of the control station and of the unmanned aircraft

• An indication of the barometric pressure altitude of the control station and of the unmanned aircraft

• A Co-ordinated Universal Time (UTC) time mark

• An indication of the emergency status of the UAS, which could include lost-link or downed aircraft

Standard remote identification UASs would be required, under this regulation, to transmit certain message elements through the internet to a Remote ID USS (an FAA-qualified third party) and to transmit the same message elements directly from the unmanned aircraft using part of the radio frequency spectrum in accordance with 47 Code of Federal Regulations CFR part 15, where operations may occur without a Federal Communication Commission FCC individual license. The FAA is proposing to define “broadcast” in this context as sending information from an unmanned aircraft using part of the radio frequency spectrum, rather than as a one-to-many transmission; in a more similar manner to the general usage in this field of the term “transmit” than the term “multicast”, or “broadcast”. Under the proposed rule, only standard remote identification UAS would be able to transmit remote identification message elements.

The FAA envisions that remote identification broadcast equipment would transmit using spectrum resources similar to those used by Wi-Fi and Bluetooth devices. The FAA is not, however, proposing a specific frequency band. Rather, the FAA envisions industry stakeholders would identify an appropriate region of the radio frequency spectrum to use for this capability and would propose solutions through the means of a compliance acceptance process. This requirement would ensure that the public has the capability, using existing commonly available and 47 CFR part 15 compliant devices, such as for example cellular phones, smart devices, tablet computers, laptop computers and other such devices, to receive these broadcast messages. Additionally, for standard remote identification UAS, it is proposed that the UAS which is transmitting the information use radio frequency spectrum resources in accordance with 47 CFR part 15 that is compatible with personal wireless devices and must be designed to maximize the range at which the broadcast can be received, while complying with the 47 CFR part 15 regulatory requirements in effect at the time. Specifically, these regulatory requirements are such that the Declaration of Compliance is submitted for FAA acceptance, and must be integrated into the unmanned aircraft or control station without modification to its authorized radio frequency parameters. This proposed requirement would ensure that producers use a means of compliance that specifies a broadcast technology or broadcast technology characteristics that maximize the broadcast range while still meeting the other minimum performance requirements under this proposed rule. Maximizing the broadcast range would ensure that remote identification information would be available to the largest number of potential receiving devices within the limits permitted by law. Maximized range would also optimize future operational capabilities, such as detect-and-avoid and aircraft-to-aircraft communications where range is a factor.

The FAA believes that a transmission rate of at least one message per second, that is a message frequency of 1 Hz, is achievable by existing systems, and is proposing that this be the minimum transmission rate for the remote identification message elements to be transmitted from the UAS whilst in operation. This requirement is a significant factor in the definition of the Technical problem herein, in that it is needed to develop a method for complying with this legal requirement and devices to perform this method, whilst minimising the resources consumed in this such as battery power for UAVs and communication resources on the network.

FIRST EMBODIMENT

We present a number of example embodiments relating to this requirement. In a first example embodiment, the UAV transmits the required information in a periodic UAV identification. The periodicity of this transmission is to be determined by the UAV, for example it may be transmit once per second, as the FAA requirement states, or it may be transmitted more frequently, allowing a greater accuracy of the location determination of the UAV by neighbouring devices over a time period between periodic transmissions, the time period being shorter and hence the UAV in general being closer to its transmission position. Because the transmission not only contains the serial number and/or session ID of the UAV but may also contain the real time flight information, it is envisaged that this information should be transmitted periodically to enable a variety of purposes, e.g. UAV status monitor, collision avoidance etc. There are a number of potential embodiments available for this periodic transmission.

In a first example embodiment, the periodic UAV identification is as part of a discovery message. It is envisaged that the message will include such elements as the identity of the UAS, indicated by the serial number assigned to the unmanned aircraft by the producer of the unmanned aircraft and/or a session ID assigned to the UAS by a remote ID UAS Service Supplier, USS, as well as an indication of the emergency status of the UAS, which may indicate that a link between the control station and the unmanned aircraft has been lost, or that the aircraft has been downed, or other suitable emergency status. The message may further include an indication of the latitude and longitude of the control station of the UAS and the unmanned aircraft, an indication of the barometric pressure altitude of the control station of the UAS and of the unmanned aircraft, a Co-ordinated Universal Time (UTC) mark. These classes of information are provided as an example of the information that might be included in the transmission, and are not intended to limit in any way the inclusion of other information that might be necessary in the transmission, such as the departure location of the unmanned aircraft, the target location of the unmanned aircraft, the estimated time of arrival and so on.

This information may be collected and included in the discovery message and transmit periodically. Because of the FAA requirement that the information be transmitted with a minimum threshold frequency of once per second, from a network point of view, there is a need for the UAS to identify and allocate the necessary communications resources for the discovery message to fulfil the requirement.

It is also noted that the inclusion of this data in the discovery message, such that there is a periodic transmission of data over the interface, may cause network conflict / interference, particularly when there are a plurality of UASs operating in the same area and the transmissions of which interfere. This can be mitigated by a number of measures, set out below.

One measure that may be implemented to reduce the interference of transmissions by UASs is that each UAV may set a backoff timer to delay the broadcast message. This backoff timer might be determined by the control station, in conjunction with a core network element so configured to allocate different backoff timers to different UAVs and thus minimise the potential for interference over the air interface, or it may be randomly allocated, either by the UAV itself or by the control station.

Another potential measure is that a network which the control station is connected to might configure at least one discovery resource pool, with accompanying discovery resource allocations, and the UAV might randomly select one of the discovery resource pools to use in transmitting the periodic UAV identification. Alternatively the UAV, in combination with the control station, might be allocated a particular discovery resource pool according to a rule or order, for example that the first discovery pool is filled before any other pools, or that an allocation of a UAV is determined in order to keep the number of UAVs assigned to each of the discovery resource pools as equal as possible, or a random number is generated between 1 and maximum number of discovery pools, then UAV will transmit the discovery message on that selected resource pool or other suitable rule.

A further potential measure to be implemented to minimise the interference of communication transmissions is that within the discovery resource pools, the resources might be implemented on a first come-first served basis, whereby the resource allocations with the smallest backoff timer are allocated to the first UAV to select that discovery resource pool. In an alternative embodiment, the communications resources in a discovery resource pool might be randomly allocated to the UAV when it is allocated to the discovery resource pool.

In one example embodiment of the present disclosure, it may be necessary to separate the UAV identification into a plurality of individual messages, whether because of a difference in a priority of the data elements, or in insufficient allocation of communications resources in one single contiguous block to allow the transmission of the data in a single transmission. In this case, it will be appreciated that some elements of the message may be included in a first discovery message, and other elements in another separate discovery message. For instance, the first discovery message might include such data elements as a serial number of the unmanned aircraft, a session ID, and an emergency status of the UAS, along with an indication of the scheduling for the following discovery message(s). The following discovery message might include lower priority data elements, such as location information relating to the UAV and control station, the UTC time mark, the indication of the barometric pressure and so on. Alternatively, the data elements relating to a higher priority might correspond to data relating to the UAV, and data elements relating to a lower priority might correspond to data relating to the control station, since the control station might be assumed to be substantially stationary when compared with the UAV in operation or related to the static data e.g. departure airport, arrival airport etc.

The first discovery message may also contain a flag bit, which indicates whether all of the data is to be received in a single discovery message when the flag bit indicates one value, for example “1” and when the flag bit is set as a different value, for example “0”, the flag bit indicates that the periodic UAV identification is to be divided over a plurality of different discovery message transmissions or the flag can indicate the discovery message are divided into how many segments. Dividing the identification transmission over a plurality of discovery messages may have the disadvantage of taking longer to transmit/receive the information required to be transmitted, but may make better use of the communications resources allocated to the UAV as well as providing more reliable information. The use of the flag bit may allow the UAS to determine if/when the plurality of messages are used and when a single discovery message is used to transmit the information, allowing flexibility in the implementation of the present disclosure.

In a second example embodiment, instead of including the UAV identification information in a discovery message, the information can be transmitted from the UAS via Configured Grant, CG, scheduling. The CG scheduling is an example of periodic transmission of the UAV identification transmission, as the discovery message example above.

This is an example of a unicast communication, rather than a multicast/broadcast communication as in the above discovery message example, and a predetermined connection is required between two UAVs for this example. A suitable interface might be the PC5 link disclosed above between two UAVs, but this is intended as an example only, to illustrate a potential link that might be used for this purpose, and is in no way a limitation of the disclosure to the use of this form of UAV-UAV link.

There are at least two modes in which the UAS can operate relating to this example embodiment and the transmission of UAV identification via CG resources. In a first mode, the network allocates to the UAS the resources required to transmit the UAV identification data, either directly to the UAV or via the control station in communication with the UAV. In a second mode, the UAV (or control station) may autonomously determine the resources that it will use to transmit the identification data to another UAV. In both modes, the message frequency requirement must be taken into account when determining the configured grant resources, and the relative periodicity of the resources so that the UAS transmits the data frequently enough to abide by the regulation.

SECOND EMBODIMENT

In a second embodiment, rather than transmitting the data relating to the UAV identification periodically, the UAV may transmit the data instead based on transmissions that the UAV or control station receive requesting the information. This request may be sent from the UAV controller, the control station, or it might be sent from another UAV, or other device. This is depicted in exemplary Figure 6, wherein the UAV identification request 601 is transmitted by UAV - A 270a, and subsequently received by UAV - B. In response to the reception of the UAV identification request 601 by UAV - B 270b, which is the one implementing the UAV identification in this example, UAV - B 270b transmits to UAV - A 270a the identification information 602.

In this example, it might be advantageous to transmit more information between devices. For instance, the UAV may transmit information other than identification information, and the particular information requested by, in this example UAV - A, may be different in different instances of the identification request. In some examples, UAV - A may request information relating to the flight information of UAV - B, such as the departure point, destination point, classification / category of UAV, weather conditions, estimated arrival time etc. This might be determined by the device requesting information, rather than by the device responding to the information request, or there may be some information elements that a responding UAV always includes in the UAV identification, in addition to the identification information, such as always including the UAV classification / category, or the altitude of the responding UAV.

Alternatively, in a separate embodiment of the present disclosure, the UAV identification request message might be based on a transmission message, that is for example, the transmission request message may be based on a discovery message with one bit set to indicate the UAV identification request or it may include more than one bit, wherein the additional bits indicate the specific information categories that are requested from the UAV. In yet another example, the request message may be based on a unicast PC5 message, e.g. a PC5-RRC message to a specific UAV. If the UAV identification request message is based on a transmission message, it may be necessary for each UAV to set a backoff timer to delay its transmission message in response in order to avoid interference and the flooding of the network with UAV identification messages from different UAVs responding to the request. In this instance, there may be a determined order by the network for allocating specific backoff timers to the different UAVs, or the backoff timers might be selected at random within a prespecified range.

THIRD EMBODIMENT

In another embodiment, in a case where a remote UAV is connected to a control station, the control station may function as a relay and re-transmit the UAV identification transmission relating to its connected UAVs. This is, as would be understood by a skilled person of the field, not limited to the example of just one remote UAV, as a single control station might control a plurality of remote UAVs, as shown in Figure 4, and the single control station may function as the relay for each of the connected UAVs. In this example scenario, there may be advantages over other example arrangements as disclosed above, such as being able to better manage the usage of radio interface resources used by the transmission of UAV identification transmissions, on account of the control station being connected to the network and a network-level scheduling of backoff timers for the UAV identification transmissions might reduce interference. Furthermore, a control station functioning as a relay node for a plurality of UAVs may be able to schedule the transmissions of multiple UAV identification in a way that the remaining resources are more suited to the transmission of data, by, for example, grouping the transmissions together. In addition, the relay node may reduce the number of communications resources used, and it may receive the relevant information for the transmission from the remote UAV via a PC5-RRC message transmitted to the relay node by the UAV.

UFES

It may be the case that the UAV receiving the UAV identification is unable to understand the format of the UAV identification information, unable to decode the transmission, or does not recognise either the producer or the session ID transmitted in the UAV identification. In this situation where the UAV is unable to receive and decode the UAV identification, or in other example situations, there are a number of measures that may be taken to address this problem.

The first measure that may be implemented is that the UAV transmitting the UAV identification might send the identification information to a UAV Flight Enablement System (UFES). The UFES may then process this information and determine an action to be taken by a second UAV, followed by controlling or indicating the UAV control station to send necessary commands to the second UAV to ensure the UAV performs the action as determined by the UFES. In other words, it may be advantageous if a UAV is unable to receive the information in the UAV identification to outsource the processing of this information to the UAV Flight Enablement System.

Alternatively, the UAV receiving the UAV identification, the second UAV in the example above, may receive from the UFES the related information e.g. the different formats, the producer of the UAV identification, the serial number, session ID etc. in a format that it is able to decode and understand, and is then able to understand the UAV identification. In this example, in the discovery message, it may also include a format indicator that the discovery message contains. With this solution, the receiving UAV may be able to act properly in case of an emergency, or other scenario that requires action from the receiving UAV, such as performing a collision avoidance manoeuvre. Within this option for obtaining the contents of the UAV identification when it is unable to decode the UAV identification sent from the UAV directly, the UAV might be preconfigured with the above information i.e. preconfigured to expect in a UAV identification a certain set of information elements in a particular order.

This may be understood further with reference to Figure 7, where such an example system is depicted. Figure 7 provides a representation of a system containing two UAVs, 270a, 270b, in operation, each controlled by separate control stations, 272a, 272b, respectively. In addition, as part of a broader network, a UFES is shown 701. In Figure 7, UAV - A, 270a, is the UAV transmitting the UAV identification. However, for a reason that is not here specified, the UAV - B, 270b, is unable to receive and decode this transmission. Therefore, UAV - B 270b requests that UAV - A transmits the UAV identification also to a UFES 701, which may be via the Control Station A, CS - A, 272a, or may be directly to the UFES, wherein for simplicity of the Figure, this link is not shown. The CS-A may then forward this transmission to the UFES. Following processing at the UFES, the UFES may then transmit the information to UAV - B either directly via an air interface or indirectly via a Control Station B, CS - B, 272b, with an encryption that it is able to decode, enabling UAV - B to determine an action to be taken in response to the UAV identification, relayed via the UFES. Alternatively, in another embodiment, the UFES may send an indication of an action for UAV - B to take, following a determination of the action that UAV - B should take by the UFES.

Another concern when broadcasting the UAV identification is security, particularly if the UAV includes in the UAV identification details related to the flight information of the UAV. To increase the security of such a transmission, the information might be transmitted with encryption applied to the data, so that, for example, a transmission signal, prior to being transmitted is encrypted with a key and then the transmission signal is sent. This key might be shared with a receiver, particularly if the receiver is a trusted receiver such as one operated by the same control station, or by the same operator, thus enabling the trusted receiver(s) to decode the encrypted UAV identification. In particular, security keys are exchanged using the same mechanism as defined for transmission/reception of encrypted positioning information. If the receiver is unable to decode the message then this can be handled by methods such as those described in co-pending European patent application published under number EP3698598 [4], the contents of which are hereby incorporated by reference. In a further embodiment, the security and integrity of the UAV identification transmissions may be ensured by using blockchain to record the messages. It is envisaged that any of these security proposals could be implemented in combination with any of the above examples relating to the transmission of data, such that the security of any UAV identification could be improved.

Those skilled in the art would appreciate that the example systems and methods described herein and with reference to the figures may be adapted in accordance with embodiments of the present technique. For example, other intermediate steps may be included in the method of Figure 6, or the steps may be performed in any logical order. Furthermore, though embodiments of the present technique have been described by way of the example communications system shown in Figure 7 for example, it would be clear to those skilled in the art that they could be equally applied to other systems to those described herein.

Those skilled in the art would further appreciate that such infrastructure equipment, communications devices, UAVs, and the like as herein defined may be further defined in accordance with the various arrangements and embodiments discussed in the preceding paragraphs. It would be further appreciated by those skilled in the art that such infrastructure equipment and communications devices as herein defined and described may, without departing from the scope of the claims, form part of communications systems other than those defined by the present disclosure.

The following numbered paragraphs provide further example aspects and features of the present technique:

Paragraph 1. A method of operating an Unmanned Aerial Vehicle, UAV, the method comprising transmitting signals, by the UAV, to a wireless communications network or to a communications device configured to communicate via the wireless communications network, the signals being transmitted via a wireless access interface between the UAV and the wireless communications network or between the UAV and the communications device, or receiving signals, by the UAV, from the wireless communications network or from a communications device configured to communicate via the wireless communications network, the signals being received via the wireless access interface between the UAV and the wireless communications network or between the UAV and the communications device, and transmitting, by the UAV, a UAV identification which includes information identifying the UAV.

Paragraph 2. The method of Paragraph 1, wherein the UAV identification includes at least one of an indication of a serial number assigned to the UAV or a session identifier assigned to the UAV by a remote identification Unmanned Aircraft System, UAS, service supplier; an indication of a time when the UAV identification transmission is transmitted; and an indication of an emergency status of the UAV.

Paragraph 3. The method of Paragraph 1 or Paragraph 2, wherein the UAV identification includes at least one of an indication of a latitude and a longitude of the UAV, an indication of a latitude and a longitude of a control station for controlling the UAV, an indication of a barometric pressure altitude of the control station, and an indication of a barometric pressure altitude of the UAV.

Paragraph 4. The method of Paragraph 1, 2 or 3, wherein the UAV identification is included in a discovery message and transmitted periodically, the discovery message being a transmission to discover available wireless communications networks and/or available wireless communications devices.

Paragraph 5. The method of Paragraph 4, wherein the UAV sets a backoff timer to delay transmitting the UAV identification.

Paragraph 6. The method of Paragraph 4, comprising receiving, by the UAV, from the wireless communications network, an indication that a plurality of discovery resource pools associated with communications resources have been configured, selecting one of the plurality of discovery resource pools, and transmitting the UAV identification in the communications resources associated with the selected resource pool.

Paragraph 7. The method of Paragraph 4, comprising receiving, by the UAV from the wireless communications network, an indication that a plurality of discovery resource pools associated with communications resources have been configured, the indication including an indication of a discovery resource pool allocated to the UAV, and transmitting the UAV identification in the communications resources associated with the allocated resource pool.

Paragraph 8. The method of any of Paragraphs 1 to 7, wherein the transmitting the UAV identification, comprises transmitting the UAV identification within a plurality of discovery messages, including at least a first discovery message and one or more other discovery messages, and the first discovery message includes an indication of scheduling information relating to the one or more other discovery messages. Paragraph 9. The method of any of Paragraphs 1 to 8, comprising receiving an indication of communications resources for the transmission of the UAV identification, the indication having been assigned by configured grant scheduling.

Paragraph 10. The method of any of Paragraphs 1 to 9, wherein the transmitting the UAV identification comprises receiving a request for the UAV identification, and in response transmitting the UAV transmission information.

Paragraph 11. The method of Paragraph 10, wherein the UAV identification contains additional information in response to the request for the UAV identification specifying at least one category of information requested.

Paragraph 12. The method of any of Paragraphs 1 to 11, wherein the transmitting the UAV identification comprises receiving, by the UAV, a request for UAV identification information from a UAV control station, and in response transmitting the UAV identification, from the UAV to the UAV control station.

Paragraph 13. The method of any of Paragraphs 1 to 12, wherein the request for UAV identification information comprises one of a unicast or broadcast transmission by the UAV control station, and the transmitting the UAV identification comprises one of a unicast or a broadcast transmission..

Paragraph 14. The method of any of Paragraphs 1 to 13, comprising receiving an indication that an Unmanned Aircraft System, UAS, or Unmanned Aircraft Vehicle, which received the UAV identification is unable to recover information conveyed by the UAV identification, and in response transmitting the UAV identification to a UAV Flight Enablement Subsystem, UFES, the UFES, on reception of the UAV identification transmission, being configured to decode the UAV identification transmission and to recode information contained therein before transmitting the information to a receiving UAS or to determine an action to be taken by the receiving UAS, and to transmit to the receiving UAS an indication of the action to be taken.

Paragraph 15. The method of any of Paragraphs 1 to 14, wherein an encryption key is sent from the UAS to a receiving UAS, to enable the receiving UAS to decode information contained within the UAV identification.

Paragraph 16. An Unmanned Aerial Vehicle, UAV, forming part of an Unmanned Aircraft System, UAS, the UAV comprising: transmitter circuitry configured to transmit signals to a wireless communications network or to a communications device configured to communicate via the wireless communications network, the signals being transmitted via a wireless access interface between the UAV and the wireless communications network or between the UAV and the communications device, receiver circuitry configured to receive signals from the wireless communications network or from a communications device configured to communicate via the wireless communications network, the signals being received via the wireless access interface between the UAV and the wireless communications network or between the UAV and the communications device, controller circuitry configured to control the UAV to transmit a UAV identification , which includes information identifying the UAV.

Paragraph 17. A UAV of Paragraph 16, wherein the UAV identification includes at least one of an indication of a serial number assigned to the UAV or a session identifier assigned to the UAV by a remote identification Unmanned Aircraft System, UAS, service supplier; an indication of a time when the UAV identification transmission is transmitted; and an indication of an emergency status of the UAV.

Paragraph 18. A UAV of Paragraph 16 or Paragraph 17, wherein the UAV identification includes at least one of an indication of a latitude and a longitude of the UAV, an indication of a latitude and a longitude of a control station for controlling the UAV, an indication of a barometric pressure altitude of the control station, and an indication of a barometric pressure altitude of the UAV.

Paragraph 19. A UAV of any of Paragraphs 16, 17 or 18, wherein the UAV identification is included in a discovery message and transmitted periodically, the discovery message being a transmission to discover available wireless communications networks and/or available wireless communications devices.

Paragraph 20. A UAV of Paragraph 19, wherein the UAV sets a backoff timer to delay transmitting the UAV identification.

Paragraph 21. A UAV of Paragraph 19, wherein the controller circuitry is configured with the receiver circuitry to receive, from the wireless communications network, an indication that a plurality of discovery resource pools associated with communications resources have been configured, and to select one of the plurality of discovery resource pools, and the controller circuitry is configured with the transceiver circuitry to transmit the UAV identification in the communications resources associated with the selected resource pool.

Paragraph 22. A UAV of Paragraph 19, wherein the controller circuitry is configured with the receiver circuitry to receive from the wireless communications network, an indication that a plurality of discovery resource pools associated with communications resources have been configured, the indication including an indication of a discovery resource pool allocated to the UAV, and the controller circuitry is configured with the transmitter circuitry transmit the UAV identification in the communications resources associated with the allocated resource pool.

Paragraph 23. A UAV of any of Paragraphs 16 to 22, wherein the controller circuitry is configured with the transmitter circuitry to transmit the UAV identification within a plurality of discovery messages, including at least a first discovery message and one or more other discovery messages, and the first discovery message includes an indication of scheduling information relating to the one or more other discovery messages. Paragraph 24. A UAV of any of Paragraphs 16 to 23, wherein the controller circuitry is configured with the receiver circuitry, to receive an indication of communications resources for the transmission of the UAV identification, the indication having been assigned by configured grant scheduling, and the controller circuitry is configured to control the transmitter circuitry to transmit the UAV identification in the assigned communications resources.

Paragraph 25. A UAV of any of Paragraphs 16 to 24, wherein the controller circuitry is configured to control the receiver circuitry to receive a request for the UAV identification, and in response to control the transmitter circuitry to transmit the UAV transmission information.

Paragraph 26. A UAV of Paragraph 25, wherein the UAV identification contains additional information in response to the request for the UAV identification specifying at least one category of information requested.

Paragraph 27. A UAV of any of Paragraphs 16 to 26, wherein the controller circuitry is configured to control the receiver circuitry to receive a request for UAV identification information from a UAV control station, and in response, to control the transmitter circuitry to transmit the UAV identification, from the UAV to the UAV control station.

Paragraph 28. A UAV of Paragraph 27, wherein the request for UAV identification information comprises one of a unicast or broadcast transmission by the UAV control station, and the transmitting the UAV identification comprises one of a unicast or a broadcast transmission. It will be appreciated that the above description for clarity has described embodiments with reference to different functional units, circuitry and/or processors. However, it will be apparent that any suitable distribution of functionality between different functional units, circuitry and/or processors may be used without detracting from the embodiments. Described embodiments may be implemented in any suitable form including hardware, software, firmware or any combination of these. Described embodiments may optionally be implemented at least partly as computer software running on one or more data processors and/or digital signal processors. The elements and components of any embodiment may be physically, functionally and logically implemented in any suitable way. Indeed the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units. As such, the disclosed embodiments may be implemented in a single unit or may be physically and functionally distributed between different units, circuitry and/or processors.

Although the present disclosure has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Additionally, although a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognise that various features of the described embodiments may be combined in any manner suitable to implement the technique.

REFERENCES

[1] RP-160671, “New SID Proposal: Study on New Radio Access Technology,” NTT DOCOMO, RAN#71

[2] Holma H. and Toskala A., “LTE for UMTS OFDMA and SC-FDMA based radio access”, John Wiley and Sons, 2009.

[3] 3GPP TS 38.825

[4] European patent application published under number EP3698598.