Interest in using cellular connectivity to support Unmanned Aerial Systems (UAS) is strong, and the 3GPP ecosystem offers excellent benefits for UAS operation. Ubiquitous coverage, high reliability and QoS, robust security, and seamless mobility are critical factors to supporting UAS command and control functions. In parallel, regulators are investigating safety and performance standards and Registration and licensing programs to develop a well-functioning private and civil UAS ecosystem which can safely coexist with commercial air traffic, public and private infrastructure, and the general population.
The 3GPP system can provide control plane and user plane communication services for UAS. Examples of services which can be offered to the UAS ecosystem includes data services for command and control (C2), telematics, UAS-generated data, remote identification, and authorisation, enforcement, and regulation of UAS operation.
The present document identifies the requirements for operation of Unmanned Aerial Vehicles (UAVs) via the 3GPP system.
This includes requirements for meeting the business, security, and public safety needs for the remote identification and tracking of UAS linked to a 3GPP subscription.
The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific.
For a specific reference, subsequent revisions do not apply.
For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
For the purposes of the present document, the terms and definitions given in TR 21.905 and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905.
Above ground level (AGL):
In the context of a UAV it is the UAV altitude referenced to ground level in the vicinity.
Command and Control (C2) Communication:
the user plane link to convey messages with information of command and control for UAV operation between a UAV controller and a UAV.
Unmanned Aerial System (UAS):
Composed of Unmanned Aerial Vehicle (UAV) and related functionality, including command and control (C2) links between the UAV and the controller, the UAV and the network, and for remote identification. A UAS is comprised of a UAV and a UAV controller.
Unmanned Aerial System Traffic Management (UTM):
a set of functions and services for managing a range of autonomous vehicle operations.
The UAV controller of a UAS enables a drone pilot to control an UAV.
radio access node on-board UAV. It is a radio access node providing connectivity to UEs, which is carried in the air by an Unmanned Aerial Vehicle (UAV).
For the purposes of the present document, the abbreviations given in TR 21.905 and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905.
An Unmanned Aerial System (UAS) is the combination of an Unmanned Aerial Vehicle (UAV), sometimes called a drone, and a UAV controller. A UAV is an aircraft without a human pilot onboard - instead, in some cases. the UAV can be controlled from an operator via a UAV controller and will have a range of autonomous flight capabilities. The communication system between the UAV and UAV controller is, within the scope of this specification and in some scenarios, provided by the 3GPP system. The UAS model considers also the scenario where the UAV controller communicates with the UAV via mechanisms outside the scope of 3GPP.
UAVs range in size and weight from small, light aircraft often used for recreational purposes to large, heavy aircraft which are often more suited to commercial applications. Regulatory requirements vary across this range and vary on a regional basis.
The communication requirements for UAS cover both the Command and Control (C2), and uplink and downlink data to/from the UAS components towards both the serving 3GPP network and network servers. The applicable C2 communication modes is depicted in clause 4.2.
Unmanned Aerial System Traffic Management (UTM) is used to provide a number of services to support UAS and their operations including but not limited to UAS identification and tracking, authorisation, enforcement, regulation of UAS operations, and also to store the data required for UAS(s) to operate. It also allows authorised users (e.g., air traffic control, public safety agencies) to query the identity and metadata of a UAV and its UAV controller.
When using 3GPP network as the transport network for supporting UAS services, the following C2 communication are considered to provision UAS services by guaranteeing QoS for the C2 communication:
Direct C2 communication:
the UAV controller and UAV establish a direct C2 link to communicate with each other and both are registered to the 5G network using the radio resource configured and scheduled provided by the 5G network for direct C2 communication.
Network-Assisted C2 communication:
the UAV controller and UAV register and establish respective unicast C2 communication links to the 5G network and communicate with each other via 5G network. Also, both the UAV controller and UAV may be registered to the 5G network via different NG-RAN nodes. The 5G network needs to support mechanism to handle the reliable routing of C2 communication.
UTM-Navigated C2 communication:
the UAV has been provided a pre-scheduled flight plan, e.g. array of 4D polygons, for autonomous flying, however UTM still maintains a C2 communication link with the UAV in order to regularly monitor the flight status of the UAV, verify the flight status with up-to-date dynamic restrictions, provide route updates, and navigate the UAV whenever necessary.
In general, Direct C2 communication and Network-Assisted C2 communication are used by a human-operator using a UAV controller. UTM-Navigated C2 communication is used by the UTM to provide cleared flying routes and routes updates. In order to ensure the service availability and reliability of the C2 communication for UAS operation, especially when the UAV is flying beyond line of sight (BLOS) of the operator, redundant C2 communication links can be established for any C2 communication links from UAV controller or UTM to a UAV.
For reliability and service availability consideration, it is impossible to activate more than one C2 communication with one as a backup link for C2 communication or switch among the applicable links for C2 communication.
For example, Direct C2 communication can be used at first and then switch to the Network-Assisted C2 communication when the UAV is flying BLOS.
For example, UTM-navigated C2 communication can be utilized whenever needed, e.g. for air traffic control, the UAV is approaching a No Drone Zone, and detected potential security threats, etc.
There are four control modes considered in the C2 communication for the UAV operation that are with different requirements, e.g. on message intervals, sizes, and end to end latencies, etc., including steer to waypoints, direct stick steering, automatic flight by UTM and approaching autonomous navigation infrastructure.
Steer to waypoints: the control message contains flight declaration, e.g. waypoints, sent from the UAV controller or UTM to the UAV. The control mode is used in both of direct C2 communication and network-assisted C2 communication.
Direct stick steering: the control message contains direction instructions sending from the UAV controller to the UAV while optionally video traffic is provided as feedback from the UAV to the UAV controller. The control mode is used in both of direct C2 communication and network-assisted C2 communication.
Automatic flight by UTM: the control message contains a pre-scheduled flight plan, e.g. array of 4D polygons, sent from the UTM to the UAV, which thereafter flies autonomously with periodic position reporting. The control mode is used in UTM-Navigated C2 communication.
Approaching autonomous navigation infrastructure: the control message contains direction instructions, e.g. waypoints, altitudes and speeds from the UTM to the UAV. When the UAV is landing/departing, the UTM coordinates more closely with autonomous navigation infrastructure, e.g. vertiport or package distribution center. The control mode is used in UTM-Navigated C2 communication.
The 3GPP system should enable UTM to associate the UAV and UAV controller, identify them as a UAS.
The 3GPP system shall be able to provide UTM with the identity/identities of a UAS.
The 3GPP system shall enable a UAS to send UTM the UAV data which can contain: unique identity (this may be a 3GPP identity), UE capability of the UAV, make & model, serial number, take-off weight, position, owner identity, owner address, owner contact details, owner certification, take-off location, mission type, route data, operating status.
The 3GPP system shall enable a UAS to send UTM the UAV controller data which can contain: unique identity (this may be a 3GPP identity), UE capability of the UAV controller, position, owner identity, owner address, owner contact details, owner certification, UAV operator identity, UAV operator license, UAV operator certification, UAV pilot identity, UAV pilot license, UAV pilot certification and flight plan.
The 3GPP system shall enable a UAS to send different UAS data to UTM based on the different authentication and authorizations level which are applied to the UAS.
The 3GPP system shall support capability to extend UAS data being sent to UTM with the evolution of UTM and its support applications in future.
Based on regulations and security protection, the 3GPP system shall enable a UAS to send UTM the identifiers which can be: IMEI, MSISDN, or IMSI, or IP address.
The 3GPP system shall enable a UE in a UAS to send the following identifiers to a UTM: IMEI, MSISDN, or IMSI, or IP address
The 3GPP system should enable an MNO to augment the data sent to a UTM with the following: network-based positioning information of UAV and UAV controller.
The 3GPP system shall enable UTM to inform an MNO of the outcome of an authorisation to operate.
The 3GPP system shall enable an MNO to allow a UAS authorisation request only if appropriate subscription information is present.
The 3GPP system shall enable a UAS to update a UTM with the live location information of a UAV and its UAV controller.
The 3GPP network should be able to provide supplement location information of UAV and its controller to a UTM.
The 3GPP network shall support UAVs and the corresponding UAV controller are connecting to different PLMNs at the same time.
The 3GPP system shall support UAVs and the corresponding UAV controller are connecting to different PLMNs at the same time.
The 3GPP system shall provide the capability for network to obtain the UAS information regarding its support of 3GPP communication capabilities designed for UAS operation.
The 3GPP system shall support the UAS identification and subscription data which can differentiate the UAS with UAS-capable UE and the UAS with non-UAS-capable UE.
The 3GPP system shall support detection, identification and reporting of problematic UAV(s) and the UAV controller to a UTM.
The 3GPP system shall enable a UAV to broadcast the following data for identifying UAV(s) in a short-range area for collision avoidance: e.g. UAV identities if needed based on different regulation requirements, UAV type, current location and time, flight route information, current speed, operating status.
The 3GPP system shall be able to support a UAV to transmit a message via network connection for identifying itself as an UAV to the other UAV(s).
The 3GPP system shall enable UAV to preserve the privacy of the owner of the UAV, UAV pilot, and the UAV operator in its broadcast of identity information.
The 3GPP system shall enable a UAV to receive local broadcast communication transport service from other UAV in short range.
A UAV shall be able to use a direct UAV to UAV local broadcast communication transport service in the coverage or out of coverage of a 3GPP network.
A UAV shall be able to use a direct UAV to UAV local broadcast communication transport service when the sending and receiving UAVs are served by the same or different PLMNs.
The 3GPP system shall support a direct UAV to UAV local broadcast communication transport service at relative speeds of up to 320kmph.
The 3GPP system shall support a direct UAV to UAV local broadcast communication transport service with variable message payloads of 50-1500 bytes, not including security-related message component(s).
The 3GPP system shall support a direct UAV to UAV local broadcast communication transport service which supports a range of up to 600m.
The 3GPP system shall support a direct UAV to UAV local broadcast communication transport service which can transmit messages at a frequency of at least 10 messages per second.
The 3GPP system shall support a direct UAV to UAV local broadcast communication transport service which can transmit messages with an end-to-end latency of at most 100ms.
The 3GPP system shall protect the transport of data between the UAS and UTM.
The 3GPP system shall protect against spoofing attacks of the UAS identities.
The 3GPP system shall allow non-repudiation of data sent between the UAS and UTM at the application layer.
The 3GPP system shall support the capability to provide different levels of integrity and privacy protection for the different connections between UAS and UTM as well as the data being transferred via those connections.
The 3GPP system shall support confidentiality protection of identities related to the UAS and personally identifiable information.
The 3GPP system shall support regulatory requirements (e.g. Lawful Intercept) for UAS traffic.
Beyond UAV related requirements, the 3GPP can be used to support for a wide range of applications and scenarios by using low altitude UAVs in various commercial and government sectors. New service level requirements and KPIs for supporting various UAV applications by the 3GPP system have been identified and specified e.g. Service requirements and KPIs related to command and control (C2), payload (e.g. camera) and the operation of radio access nodes on-board UAVs.
The 3GPP system shall provide means to allow a 3rd party to request and obtain real-time monitoring the status information (e.g., location of UAV, communication link status) of a UAV.
Based on operator's policy, the 3GPP system shall provide means to provide a 3rd party with the information regarding the service status for UAVs in a certain geographical area and/or at a certain time.
The 3GPP network shall be able to support network-based 3D space positioning (e.g., with altitude 30~300m) of a UE onboard UAV.
The 3GPP system shall be able to notify the authorized third party of potential stopping of connectivity service before the UE onboard of UAV enters an area (e.g., due to altitude) where the connectivity service is not authorized for the UE.
The 3GPP system shall support C2 communication with required QoS for pre-defined C2 communication models (e.g. using direct ProSe Communication between UAV and the UAV controller, UTM-navigated C2 communication based on flight plan between UTM and the UAV).
The 3GPP system shall support C2 communication with required QoS when switching between the C2 communication models.
The 3GPP system shall support a mechanism for the UTM to request monitoring of the C2 communication with required QoS for pre-defined C2 communication models (e.g. using direct ProSe Communication between UAV and the UAV controller, UTM-navigated C2 communication between UTM and the UAV).