Non-terrestrial cellular communication infrastructure

Abstract

Non-terrestrial cellular communication infrastructure. This infrastructure (1) comprises: an IP / MPLS transport network (3) including a satellite network (20) and a terrestrial network, connected by a feed link; a 5G NTN network (2), including a base station disaggregated on either side of an F1 interface, associating an edge unit (RU, DU) in the payload of a satellite (21) connected to an edge router (210) of the satellite network, and a ground unit (CU) connected to a ground router (260) of the terrestrial network; the transport network establishing a path between the ground router and the edge router; and a control center (50) for managing a configuration of transport network resources. Figure for the abstract: Figure 2

Description

Title of the invention: Non-terrestrial cellular communication infrastructure

[0001] The invention relates to the field of non-terrestrial cellular networks - NTN (“Non-Terrestrial Networks”), in particular those using DVB technology or, preferably, those using 5th generation technology - 5G, as standardized by the 3GPP (“3rd Generation Partnership Project”) standardization body.

[0002] A non-terrestrial cellular network integrates a satellite layer and a cellular layer.

[0003] The satellite layer comprises a constellation of LEO or MEO satellites, which are interconnected to form a mesh-type satellite network. Each satellite constitutes a node in this network. A data link – the Link Access Layer (ISL) – between two nodes of this network is established via an optical or radio link. Preferably, communications on the satellite network, i.e., along the ISL links, are carried out using the Ethernet protocol. The satellite layer also includes a function for controlling the satellites and the resources of the satellite layer, such as the payload of each satellite and the ground stations.

[0004] The 3GPP produces standards defining the requirements, architectures and operating procedures for the cellular layer.

[0005] Although the first normative elements relating to non-terrestrial cellular networks were defined in version 17 of the 5G standard (“Release 17”, completed in June 2022), normative work continues.

[0006] Thus, the cellular layer of a 5G NTN network is studied more specifically in the technical specifications 3GPP TS 38.300 and 3GPP TS 23.501 as well as in the technical reports 3GPP TR 23.700-28, 3GPP TR 23.700-29, 3GPP TR 23.737, 3GPP TR 38.821.

[0007] The latest findings of these studies, or recommendations, will be incorporated into version 19 of the 5G standard, which is expected to be published in June 2026.

[0008] These recommendations propose, in particular, a 5G NTN network architecture in which all or part of a base station (also called a gNode-B or gNB) is integrated into the payload of a satellite and participates in the processing of data packets. This is referred to as a regenerative architecture. The regenerative 5G NTN network can reduce the number of ground stations and also provide connectivity services with higher data rates than a 5G NTN network that uses satellites solely to transparently retransmit data packets.

[0009] The regenerative architecture uses the flexibility of the NG-RAN architecture which allows different disaggregation options for a gNB on either side of a standardized interface: - A high layer split of the gNB (“Higher Layer Split” or HLS), as specified in 3GPP TS 38.401: a gNB consists of a gNB-CU and one or more gNB-DU(s), and the interface between gNB-CU and gNB-DU is called Fl; - A low-layer split (LLS), as defined in the O-RAN Architecture Description: a gNB consists of a network function (O-DU) and a radio function (O-RU), and the interface between the O-DU and O-RU is called the Open FrontHaul. The O-DU supports the functions of a gNB-DU as specified in 3GPP TS 38.401.

[0010] The set formed by the RF and Low-PHY physical layers corresponds to a gNB-RU or O-RU radio unit (“Radio Unit”). They allow the establishment of a service link Uu with a user equipment - UE (“User Equipment”).

[0011] With this separation of the gNB, the components of the lower part of the gNB are carried on board a satellite and the components of the upper part of the gNB are on the ground, in a ground station.

[0012] From the ground station, the upper part of the gNB connects via an NG interface to a 5G - CN (“Core Network”) core network, comprising for example a gateway to a public network, such as the Internet.

[0013] Knowing that the payload of a satellite remains constrained in terms of computing capacity, the positioning of the separation in the protocol stack has the advantage of being able to offload functions to the ground, in order to adapt to the processing capacity of the payload of a satellite.

[0014] The low-level components of the gNB are carried on board a first satellite of the constellation, which serves a ground cell and enables the establishment of a user link with a user equipment UE present in this cell.

[0015] The ground station is in contact with a second satellite of the constellation, by a so-called feeder link.

[0016] The gNB separation interface is therefore established along the Feeder link and a route through the mesh network linking the first satellite and the second satellite.

[0017] Unlike the case of a geostationary Earth Orbit (GEO) satellite constellation, in the case of a non-geostationary satellite constellation, whether in low Earth Orbit (LEO) or medium Earth Orbit (MEO), a fixed 5G NR cell on the ground is not always served by the same first satellite, due to the satellites' movement relative to the ground. Similarly, the same second satellite is not always within line of sight of the ground station. For example, the characteristic time of visibility of a cell or ground station by a LEO satellite is on the order of a few minutes.

[0018] However, 3GPP does not include, within the scope of standardization, the definition of a mobile satellite infrastructure enabling the implementation of the separation of a gNB.

[0019] The aim of the present invention is therefore to propose a mobile satellite infrastructure supporting a functional implementation of the separation of a gNB.

[0020] To this end, the invention relates to a non-terrestrial cellular communication infrastructure, comprising a satellite component and a ground component, the satellite component comprising a constellation of satellites, each satellite carrying an on-board router, the on-board routers forming a satellite network of the mesh type, the ground component comprising: a terrestrial network, comprising a plurality of ground routers; and a ground station connected on the one hand to the terrestrial network and on the other hand to a satellite of the satellite constellation by a feed link, characterized in that the infrastructure comprises a cellular communication network, comprising: a core network forming part of the ground component; a plurality of on-board units;and a plurality of ground units, each edge unit being carried on board a satellite of the satellite constellation and connected to an edge router at the end of the satellite network, each ground unit, which is part of the ground component, being connected between an edge ground router at the end of the terrestrial network and the core network, a disaggregated base station resulting from the pairing, on either side of a standardized interface, of an edge unit and a ground unit;in that the infrastructure includes a transport network, supporting the standardized interface of each disaggregated base station present in the cellular communication network, the transport network aggregating the satellite network and the terrestrial network linked to each other by the feed link, the transport network enabling the definition, for each disaggregated base station present in the cellular communication network, of a path between the end ground router connected to the ground unit of said disaggregated base station and the end edge router connected to the edge unit of said disaggregated base station, the transport network implementing an IP / MPLS type routing protocol;and, in that, considering that pseudo-cells of the cellular communication network are fixed and predefined, and that each pseudo-cell is associated with a ground unit from the plurality of ground units, the infrastructure includes a control center adapted to establish a mission plan, the mission plan indicating, for each pseudo-cell, at what time an edge unit from among the plurality of edge units will serve said pseudo-cell, said edge unit being thus paired with the ground unit associated with the pseudo-cell to constitute a disaggregated base station, and to command, at each instant, a configuration of the network resources of; cellular communication and a configuration of transport network resources to carry out the mission plan and enable the exchange of data packets between the pseudo-cell and the associated ground unit.

[0021] According to other advantageous aspects of the invention, the infrastructure comprises one or more of the following features, taken individually or in all technically possible combinations:

[0022] - the cellular communication network is of the 5G NTN type or of the DVB type.

[0023] - a separation between a ground unit and an edge unit of a disintegrated base station is a high layer separation and the normalized interface is the Fl interface.

[0024] - a separation between a ground unit and an edge unit of a disintegrated base station is a lower layer separation and the standardized interface is the "OpenFrontHaul" interface.

[0025] - the control center defines, at any given moment, a plurality of network services on the transport network, a network service being associated with each pair consisting of an edge unit and a ground unit, which are paired together to form a disaggregated base station, to route data packets between said edge unit and said ground unit.

[0026] - the network service is a pseudo-wire between the edge router connected to the edge unit and the ground router connected to the ground unit.

[0027] - the control center receives a set of logical services expressing the needs communications, and associated at least one network service with each logical service.

[0028] - the control center includes a resource allocation component, a a resource management component of the cellular communication network, and a resource management component of the transport network.

[0029] - the satellite constellation is a non-geostationary constellation of satellites in low Earth orbit or medium Earth orbit satellites.

[0030] - a pseudo-cell is a cell, a cell associated with a slice, a cell associated with a slice and a user, or a cell associated with a slice, a user and a quality of service.

[0031] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0032] [Fig.1] The [Fig.1] is a representation of the functional separation options of a gNB base station;

[0033] [Fig.2] Fig.2 is a schematic representation of an embodiment preferred architecture of a non-terrestrial cellular communication network according to the invention;

[0034] [Fig.3] Fig.3 is a schematic representation of a preferred embodiment of an operating method; and,

[0035] [Fig.4] [Fig.4] shows the structure of the different identifier lookup tables used in the infrastructure of [Fig.2].

[0036] In general, the infrastructure according to the invention comprises:

[0037] - a cellular communication network, complying with the regenerative 5G NTN standard with a distributed NG-RAN (“Next Generation Radio Access Network”) radio access network, in which the base stations - gNBs are disaggregated on either side of a separation interface, with an edge unit of a gNB being on board a satellite and a base unit of a gNB being on the ground;

[0038] - a transport network, which interconnects the components of the radio access network distributed cellular communication network. The transport network provides transport services that enable traffic to be routed between the edge and the ground at the required granularity (defined by a pseudo-cell), at least that of a 5G NR cell and advantageously that of a radio network slice per 5G NR cell. The transport network provides, in particular, an MPLS transport service. It is referred to as the MPLS transport network in the following;

[0039] - a resource management control center enabling the orchestration, at each instant of infrastructure use and in a synchronized manner, the configuration of the cellular communication network and that of the MPLS transport network, assuming fixed ground-based and predefined 5G NR cells and that a 5G NR cell is associated with the upper part of a single gNB.

[0040] This specific combination of means makes it possible to automatically ensure the continuous reconfiguration required by a constellation of satellites moving relative to the ground in order to maintain the continuity of communications required for users. Indeed, due to the movement of the satellites, a 5G NR cell is only temporarily covered by a particular satellite, and the ground station carrying the upper part of the gNBs is only temporarily covered by a particular satellite.

[0041] This dynamic reconfiguration is carried out without changing the network addresses used by the interfaces of the cellular communication network functions.

[0042] Fig. 1 represents the different possible options for functional separation of a gNB.

[0043] From bottom to top, a gNB consists of a protocol stack comprising, for example:

[0044] - RF functions;

[0045] - low physical functions, Low-PHY;

[0046] - high physical functions, Hi-PHY;

[0047] - a low MAC function, Low- MAC;

[0048] - a high MAC function, Hi-MAC;

[0049] - a low RLC function, Low- RLC;

[0050] - a high RLC function, Hi-RLC;

[0051] - a PDCP function of the user plane, PDCP-U, associated with an SDAP function connected to a UPF network function;

[0052] - a PDCP function of the control plane, PDCP-C, associated with an RRC layer and connected to an AMF network function;

[0053] The UPF and AMF network functions are located in a core network - CN ("Core Network") and the other layers are located in a gNB and define a gNB.

[0054] The infrastructure according to the invention is compatible with the two functional separations of the gNB indicated in the introduction to this application.

[0055] In what follows, the invention will be presented more particularly in the context of a high-level layer (HLS) separation. Preferably, separation option 3 is implemented, as illustrated in [Fig. 1]. The Fl interface is then, in this case, between the low-RLC and high-RLC layers.

[0056] The interface is supported by a transport layer implemented by the transport network.

[0057] 3GPP considers that the transport network specifications are not part of the standardization scope of this organization, which only mentions the presence of a transport layer ensuring the connectivity necessary for the functions of the cellular communication network in terrestrial or non-terrestrial cases.

[0058] Fig. 2 is a schematic representation of a possible embodiment of a mobile satellite infrastructure for a fifth-generation non-terrestrial cellular communication network according to the invention.

[0059] Infrastructure 1 allows user equipment, such as the first user equipment 11, to access, via an air interface, remote services, such as communication with other user equipment, such as the second user equipment 12, or data servers, such as the data server 14.

[0060] Infrastructure 1 comprises a satellite component 10 and a ground component 40.

[0061] The satellite component 10 comprises a constellation of satellites. For example, as illustrated in [Fig.2], the constellation comprises a first satellite 21, a second satellite 22, a third satellite 23, a fourth satellite 24 and a fifth satellite 25.

[0062] The satellites of the satellite constellation are connected to each other to form a satellite network 20 of the mesh network type.

[0063] Each satellite constitutes a node of this satellite network 20.

[0064] Two satellites in contact are linked by a data link - ISL (“Inter Satellite Link”).

[0065] Communications on the satellite network 20, i.e. along the ISL links, are carried out according to the Ethernet protocol.

[0066] Each satellite includes a satellite network access interface 20.

[0067] For example, satellites 21 to 25 each have a network interface referenced as 210, 220, 230, 240 and 250 respectively.

[0068] To simplify the description, it is assumed that these network interfaces also perform a router function on network 20, instead of considering a dedicated component, separate from the corresponding network interface.

[0069] Fig. 2 represents a moment in the operation of the infrastructure 1 in which the lower part of the gNB on board the first satellite 21 serves the cell 31 and the fifth satellite 25 is in view of the ground station 42 hosting the upper part of the gNB associated with the cell 31.

[0070] The different satellites are identical to each other. Each satellite has, in particular, the two capabilities of serving a cell and serving a ground station.

[0071] Satellite 21 is more particularly described below in its ability to establish a Uu service link with user equipment.

[0072] Satellite 21 is a communications satellite. It carries a payload integrating the hardware and software necessary for the implementation of the various communication functionalities.

[0073] Satellite 21 includes, in particular, antenna means 310 enabling it to serve at least one ground coverage area, or cell. In what follows, for the sake of clarity, a single cell is considered.

[0074] A ground user device, such as the first device 11 located in the first cell 31, can then establish a service link Uu with the satellite 21.

[0075] In accordance with the breakdown in [Fig. 1], the payload of satellite 21 comprises:

[0076] - a radio unit - RU, 310; and,

[0077] - a distributed unit - DU, 320.

[0078] The distributed unit - DU, 320, is associated with an embedded encapsulation / decapsulation interface, 330, the distributed unit - DU, 320, being connected, via said interface 330, to the edge end router 210.

[0079] Satellite 25 is more particularly described below in its ability to establish a Feeder link with the ground station associated with cell 31.

[0080] Satellite 25 carries a payload integrating the hardware and software necessary for the implementation of the various communication functionalities with ground stations.

[0081] Satellite 25 includes, in particular, a "feeder" interface 410 for wireless communication with the ground component 40, along a feeder link. The feeder interface 410 is connected to interface 250.

[0082] The terrestrial component 40 comprises:

[0083] - a ground station, 42, connected to the satellite component 10 by at least a Feeder link, the ground station 42 comprising an RF unit, 420, for communication with one or the other of the satellites of the constellation presenting a feed interface 410, in visibility at the current time, for example satellite 25 as shown in [Fig.2];

[0084] - a terrestrial network, comprising a plurality of ground routers, of which at least one 260 end ground router;

[0085] - at least one centralized unit - CU on the ground, 350, associated with an interface ground encapsulation / decapsulation, 340, and connected via said interface to the end ground router 260;

[0086] - a network core - terrestrial CN 44, to which the CU 350 is connected;

[0087] - possibly, one or more other terrestrial base stations, such as the gNB 45 and / or a terrestrial network 46, such as the Internet, connected to the CN 44.

[0088] Infrastructure 1 comprises N fixed and predefined cells. Infrastructure 1 therefore comprises N ground CUs, each ground CU being associated with a single cell. The different ground CUs are hosted in the different ground stations, a ground station being able to host more than one CU.

[0089] For example, the ground station 40 includes a CU 350 associated with the cell 31.

[0090] A CU of a ground station is connected to a CN.

[0091] For example, the CU 350 is connected to the CN 44, on the one hand, via its RRC layer and a link N2, to the AMF layer of the CN and, on the other hand, via its SDAP layer and an N3 link, to the UPF layer of the CN.

[0092] The CN 44 includes all the services of a 5G core network. For example, it is connected to the terrestrial gNB 45 and the terrestrial network 46. The gNB 45 serves, for example, a ground cell 32, which allows a user device 12, present in this cell, to establish a user link Uu with the gNB 45. The terrestrial network 46 allows access to various services, notably those provided by servers, such as the data server 14 connected to the terrestrial network 46.

[0093] A gNB base station consists of a lower part on board a satellite and an upper part on the ground. In the example of the present embodiment, the lower part of the gNB consists of the RU and the DU, while the upper part of the gNB consists of the CU. In other words, at the moment illustrated in [Fig. 2], the CU 350 is associated with the DU 320 and the RU 310 to together form a gNB serving cell 31.

[0094] Unit 330 on the one hand and unit 340 on the other hand allow data to be tagged in 5G NTN format with a key, as will be described more precisely below.

[0095] The terrestrial component 40 further includes a control center 50 for managing the infrastructure resources 1, enabling the resources of the 5G layer 2 and those of the transport layer 3 to be managed in a coherent manner to enable interactions between these layers in order to ensure continuity of communication.

[0096] Preferably, the control center 50 is a computer comprising computing means, such as a processor, and storage means, such as memory. The memory stores, in particular, the instructions for computer programs enabling the center 50 to be equipped with a resource allocation component 510, a radio resource management component 520, and a transport network resource management component 530.

[0097] To route data between the two parts of gNB of layer 5G 2, edge and ground, the infrastructure 1 includes a transport layer 3.

[0098] In the embodiment of [Fig.2], the transport layer comprises the satellite network 20, as well as the ground router 260, connected to the satellite network 20 via the Feeder link.

[0099] The CU is thus connected (via unit 340) to an ingress router on the transport network, which is router 260 in the embodiment of [Fig.2]. This router is called the ground router, since it allows the connection of the ground part of the gNB to the transport network.

[0100] In parallel, the DU is connected (via unit 330) to an ingress router on the transport network, which is a constellation router, in this case router 210 of satellite 21. This router is called the edge router, since it allows the connection to the transport network of the edge part of the gNB.

[0101] Alternatively, the CU and unit 340 could be connected to the satellite network 20, by a ground network, between unit 340 and RF unit 420. The transport layer would then include, in addition to the satellite network, this ground network.

[0102] Transport layer 3 implements a routing technology that complies with the MPLS standard.

[0103] According to this routing technology, an end-to-end MPLS tunnel is established, that is, between the ground router and the edge router. The ground and edge routers encapsulate / decapsulate the 5G NTN format data, correctly tagged by the 330 and 340 conversion units, into MPLS format to enable its transport in transport layer 3.

[0104] MPLS routing as such is limited to the routers of the constellation, between two edge routers (input and output) of the satellite network 20, i.e. routers 250 and 210 on the [Fig.2].

[0105] MPLS routing technology is implemented because it is compatible with the separation options mentioned above.

[0106] MPLS routing technology is also implemented because it provides a traffic engineering mechanism. Traffic engineering on an IP / MPLS network is defined as the set of means and procedures for evaluating and optimizing the operational performance of that IP / MPLS network.

[0107] MPLS routing technology also allows, in a particularly advantageous way, the management of faults and various degradations that may affect the transport network (in particular the influence of meteorology, the orientation of satellites with respect to the sun, the autonomy of satellites, etc.).

[0108] But above all, MPLS routing technology is implemented because it relies on Label Switched Path (LSP) routing. This allows data flows to be grouped by equivalent routing class so that they are transported along the same path. In particular, data flows can be grouped into point-to-point network services on the MPLS transport network, called pseudowires (PWs). Each pseudowire is assigned a service label, the uniqueness of which is guaranteed among the routers.

[0109] The present invention relies on the assumption of cells fixed to the ground.

[0110] Each cell is identified by a cell identifier, ID_Cell and each one-cell network slice is identified by a slice identifier, ID_Tranche.

[0111] Each cell is associated with a specific CU of a ground station. A CU supports one or more FL interfaces. Each FL interface supported by a CU constitutes an endpoint, which is identified by a CU endpoint identifier, CU_EP_F1. The CU_EP_F1 identifier combines, for example, an IP address as well as additional identifiers which may be a VLAN identifier, an MPLS tag, a Segment Routing (SID) tag, or an SRv6 tag.

[0112] A first CU table, Tl, thus associates with each pair of identifiers ID_Cell and ID_Slice, a unique endpoint identifier CU_EP_F1.

[0113] A CU is connected to a ground router, which is identified by an IP address on the transport network, IP_Ground_Router.

[0114] At a given time t, a cell ID_Cell is served by a particular DU. A DU supports one or more FL interfaces. Each FL interface supported by a DU constitutes an endpoint, which is identified by a DU endpoint identifier, DU_EP_F1. The identifier DU_EP_F1 combines, for example, an IP address and additional identifiers such as a VLAN identifier, an MPLS tag, a Segment Routing (SID) tag or an SRv6 tag.

[0115] At a given time t, a second DU table, T2, associated with a pair of identifiers ID_Cell and ID_Slice, a unique endpoint identifier DU_EP_F1.

[0116] A DU is connected to an edge router, which is identified by an IP address on the transport network, IP_Edge_Router.

[0117] A network service, identified by the identifier ID_Service_Réseau, is defined to establish bidirectional connectivity between the end identifiers CU_EP_F1 and DU_EP_F1 in order to transport traffic from the ID_Slice of the cell ID_Cell through the Fl interface on the transport network. The network service can be a point-to-point tunnel or a pseudo-wire delivered across the transport network.

[0118] At a given time t, a third table T3 is therefore defined which associates with each identifier ID_Service_Réseau, an identifier CU_EP_F1 and an identifier DU_EP_F1. This table therefore makes it possible to map the resources of the cellular communication network and the resources of the transport network.

[0119] A path ID_Path is defined between a ground router IP_Ground_Router and an edge router IP_Edge_Router

[0120] Advantageously, a set of different paths ID_Grp_Chemins can be defined between these two routers in order to support traffic engineering mechanisms.

[0121] A fourth table T4 is then defined which associates with each ID_Chemin identifier, the ID_Grp_Chemins identifier of the path group to which it belongs, the identifier of the ground router IP_Router_Ground and the identifier of the edge router IP_Router_Edge.

[0122] Alternatively, the definition of a path could be made by defining on the one hand a path on the ground transport network and on the other hand a path on the satellite transport network, these two paths being joined at the level of the routers connected by a Feeder link.

[0123] The paths can be MPLS LSP type tunnels, Segment-Routing-Traffic Engineering LSP (SR-TE LSP) type tunnels, Traffic Engineering-MPLS LSP (TE-MPLS LSP) type tunnels or SRv6 tunnels or IP tunnels (GRE, VxLAN, IPinlP).

[0124] At each time t, a fifth table T5, which is a routing table stored by each router in the infrastructure, is defined allowing a network service, ID_Service_Réseau to be associated with a path in the group ID_Grp_Chemins.

[0125] Thus, for an uplink communication from the CU to the cell, the CU 350 consults the first table Tl to identify the Fl interface associated with the ID_Cell, IDSlice pair receiving the packets and forwards the packets to this FL interface

[0126] At the Fl interface, unit 340 encapsulates packets from the CU, with the corresponding CU identifier, CU_EP_F1 (known to the Fl interface) and transmits the encapsulated packets to ground router 260.

[0127] The sol 260 router classifies encapsulated packets according to the DU identifiers they carry, CU_EP_F1, in order to assign them to a specific network service, ID_Service_Réseau, by consulting the third table T3. The sol 260 router adds to each encapsulated packet the label of the corresponding network service, ID_Service_Réseau.

[0128] The packets are then routed through the transport network from ground router 260 to edge router 210 following the path ID_Path associated with the network service ID_Network_Service, in accordance with the indications of the T5 routing table.

[0129] By consulting the third T3 channel, the edge router 210 routes packets according to their ID_Service_Network label to unit 330 corresponding to the identifier DU_EP_F1, while removing the network service label beforehand.

[0130] Unit 330 identifies the cell and network slice to which the cellular data belong based on the DU_EP_F1 identifier of the received packets, by consulting the second table T2.

[0131] The DU can then forward each packet to the UE 11 via the RU 310.

[0132] Symmetrically, for an upward communication (from the control plane or (of the data plane) from DU 320 to CU 350, cellular data packets are identified by cell ID_Cell and network slice ID_Slice.

[0133] The DU 320 consults the second T2 table to identify the Fl interface associated with the ID_Cell, IDSlice pair and transmits the packets to the identified Fl interface.

[0134] The packets are encapsulated by unit 330 associated with the identified Fl interface, with the identifier DU_EP_F1 (known to unit 330) and transmits the encapsulated packets to edge router 210.

[0135] Edge router 210 selects the network service associated with the received encapsulated packets based on their DU_EP_F1 identifier, by consulting the third table T3. Edge router 210 returns the ID_Service_Réseau label of the selected service to the packets.

[0136] The packets thus obtained are routed through the transport network from edge router 210 to ground router 260, following the path associated with the selected network service, according to the T5 routing table.

[0137] The ground router 260 forwards the received packets according to their ID_Service_Network label to the unit 340 associated with this label in the third table T3, while first removing the network service label.

[0138] Unit 340 identifies the cell and network slice to which the cellular data belongs based on the CU_EP_F1 identifier of the received packets and in consulting the first table Tl. It transmits this data to CU 350 after removing the identifier CU_EP_F1.

[0139] Fig. 3 illustrates how the control center 50 operates to manage the infrastructure 1, in particular by defining, at each moment, the different tables necessary for packet exchanges and transmitting them to the infrastructure components using these tables.

[0140] The resource allocator component or 510 orchestrator is responsible for developing a mission plan.

[0141] The mission plan indicates, for an infrastructure 1 operating period, at each infrastructure operating time step, the configuration in which the infrastructure must be.

[0142] To achieve this, in step 610, the orchestrator component 510 defines the 5G radio resources to be implemented in the satellites, i.e., the configuration parameters of the unit or each unit. Parameters such as the frequency or frequencies used and the channeling selected for each 5G NR cell are defined at this level.

[0143] For this step, the orchestrator component 510 received the communication requirements in the form of a set of logical services between ground points of presence (POPs) and fixed ground geographic coverages. These geographic coverages will host the terminals of the constellation and correspond, for example, to a collection of fixed ground cells, each identified by a pair (ID_Cell, ID_Slice). The logical service between the POPs and the geographic areas specifies the bandwidth requirements according to standard characteristics (guaranteed bandwidth, best effort, latency, etc.).

[0144] In a step 620, component 510 develops the mission plan from a map (which defines the geographical coverage on the ground by a set of cells) and the ephemerides of the constellation (which gives the instantaneous position of each satellite).

[0145] This information makes it possible to determine, for each cell ID_Cell used at time t, which satellite will serve this cell.

[0146] Based on this information, in step 630, the orchestrator component 510 allocates a network service ID_Service_Réseau to each logical service. This allocation takes the form of an allocation table. The orchestrator component 510 can make this decision based on knowledge shared between the orchestrator 510 and the manager 520, which updates the routing table T5 at each time t. This shared knowledge can be based on the provisioning of parameters in the orchestrator component 510, which allows it to determine the allocation table for a given satellite. Alternatively, it can also result from a dynamic exchange between The orchestrator component 510 and the manager 520: the orchestrator component 510 can allocate a DU_EP_F1 identifier to each pair (ID_Cell, ID_Slice) served by a satellite.

[0147] In a step 640, the orchestrator component 510 selects, for each network service ID_Service_Réseau, a path ID_Chemin within the transport network in the group of paths ID_Grp_Chemins associated with the identifier ID_Service_Réseau in the fourth table T4.

[0148] This selection is made according to the objectives required by the corresponding logical service (such as guaranteed throughput, maximum throughput, maximum delay, jitter, packet loss rate). To do this, the orchestrator component 510 uses a transport network topology, which it can receive from component 530 or by directly processing information sent by a ground router.

[0149] Once the mission plan is built, the orchestrator component 510 transmits it (step 650) on the one hand to component 530 and on the other hand to component 520.

[0150] The mission plan contains, for example, information such as: a list of cells to be created or deleted in each satellite, the allocation to each cell of a beam from the satellite's antenna system, the list of network services with their path in the constellation, etc.

[0151] In a step 710, the radio resource management component 520, which is identifiable as an SMO / RIC component (“Service Management and Orchestration / RAN intelligent Controller” or “service management and orchestration / RAN intelligent controller”) according to the O-RAN standard, implements the part of the mission plan that concerns it.

[0152] In a planned manner, for each time step, it develops and transmits commands to the elements of the 5G layer 2 in order to properly configure the radio resources, in particular on board the satellites (parameterization of the DU / RU components and pairing between DU / RU on board and CU on the ground to form a gNB).

[0153] Furthermore, in a step 720, the radio resource management component 520 regularly maintains up-to-date information on the use of radio resources, for the orchestrator component 510.

[0154] In a step 810, the network resource management component 530, which is identifiable as a Software-Defined Networking Controller (SDNC), implements the portion of the mission plan relating to the transport network. For example, it destroys obsolete pseudowires, maintains existing pseudowires, and creates new pseudowires to account for changes over time in DU-CU pairings.

[0155] In a planned manner, for each time step, it develops and transmits commands to the elements of transport layer 3 in order to properly configure the transport network resources, including the T5 routing table to define the path associated with each network service at each router level.

[0156] Furthermore, in a step 820, the network resource management component 530 regularly maintains an up-to-date view of the IP / MPLS network topology for the orchestrator component 510.

[0157] Many variants are conceivable, particularly with regard to the infrastructure and its orchestration at every moment by means of control 50.

[0158] In particular, a ground station can be associated with several CUs and / or a CU can be associated with several ground stations. This allows for the introduction of different routing scenarios, such as:

[0159] - Incident: The feeder link between a satellite and a ground station is unusable (because of rain for example) and the control means will then choose a path for the packets between a CU and a DU which passes through another Feeder link between another satellite and another ground station.

[0160] - association between a CU and a DU: when a satellite establishes a new Feeder link With a new ground station, the control means and the 5G network establish a new Fl interface between the DU and the CU associated with this new ground station and deallocates the Fl interface between the DU and the CU associated with the previous ground station.

[0161] The present infrastructure offers the ability to guarantee the continuity of a logical service and to monitor this logical service by combining data on the network services that successively serve it.

[0162] The present infrastructure offers high availability and traffic engineering mechanisms. It is compatible with different ways of distributing a base station between ground and air. It allows for consideration of the dynamics of LEO and MEO constellations (frequent change of satellite serving a ground cell, frequent change of satellite serving a ground station, degraded operating mode of the infrastructure).

Claims

1. Demands Non-terrestrial cellular communication infrastructure (1), comprising a satellite component (10) and a ground component (40), the satellite component comprising a constellation of satellites (21, 22, 23, 24, 25), each satellite carrying an edge router, the edge routers forming a satellite network (20) of the mesh network type, the ground component comprising: a terrestrial network, comprising a plurality of ground routers (260); and a ground station (42) connected on the one hand to the terrestrial network and on the other hand to a satellite of the satellite constellation by a feed link, characterized in that the infrastructure comprises a cellular communication network (2), comprising: a core network (44) forming part of the ground component; a plurality of edge units;and a plurality of ground units, each edge unit being carried on board a satellite of the satellite constellation and connected to an edge router at the end of the satellite network, each ground unit, which is part of the ground component, being connected between an edge router at the end of the terrestrial network and the core network, a disaggregated base station resulting from the pairing, on either side of a standardized interface, of an edge unit (RU, DU) and a ground unit (CU); in that the infrastructure comprises a transport network (3), supporting the standardized interface of each disaggregated base station present in the cellular communication network (2), the transport network aggregating the satellite network and the terrestrial network linked to each other by the feed link, the transport network enabling the definition, for each disaggregated base station present in the cellular communication network (2), of a path between the lateral ground router (260) connected to the ground unit (CU) of said disaggregated base station and the lateral edge router (210) connected to the edge unit (RU, DU) of said disaggregated base station, the transport network implementing an IP / MPLS routing protocol; and, in that, considering that pseudo-cells of the cellular communication network (2) are fixed and predefined, and that each where a pseudo-cell is associated with a ground unit of the plurality of ground units, the infrastructure includes a control center (50) adapted to establish a mission plan, the mission plan indicating, for each pseudo-cell, at what time an edge unit (RU, DU) among the plurality of edge units will serve said pseudo-cell, said edge unit being thus paired with the ground unit associated with the pseudo-cell to constitute a disaggregated base station, and to command, at each time, a configuration of the resources of the cellular communication network (2) and a configuration of the resources of the transport network (3) to carry out the mission plan and allow the exchange of data packets between the pseudo-cell and the associated ground unit (CU), a pseudo-cell being a cell, a cell associated with a slice, a cell associated with a slice and a user, or a cell associated with a slice, a user and a quality of service.

2. Infrastructure according to claim 1, wherein the cellular communication network is of the 5G NTN type or of the DVB type.

3. Infrastructure according to claim 1 or claim 2, wherein a separation between a ground unit and edge unit of a disaggregated base station is a high-layer separation and the normalized interface is the Fl interface.

4. Infrastructure according to claim 1 or claim 2, wherein a separation between a ground unit and edge unit of a disaggregated base station is a low layer separation and the normalized interface is the "OpenFrontHaul" interface.

5. Infrastructure according to any one of claims 1 to 4, wherein the control center (50) defines, at any given time, a plurality of network services on the transport network, a network service being associated with each pair consisting of an edge unit and a ground unit, which are paired together to form a disaggregated base station, to route data packets between said edge unit and said ground unit.

6. Infrastructure according to claim 5, wherein a network service of the plurality of network services is a point-to-point network service on the transport network, or pseudo-wires, between the edge router connected to the edge unit (RU, DU) and the ground router connected to the ground unit (CU).

7. Infrastructure according to claim 5 or claim 6, wherein the control center (50) receives a set of logical services, each logical service expressing communication needs and being associated with at least one network service.

8. Infrastructure according to any one of claims 5 to 7, wherein the control center (50) includes a resource allocation component (510), a cellular communication network resource management component (520), and a transport network resource management component (530).

9. Infrastructure according to any one of claims 1 to 7, wherein the satellite constellation is a non-geostationary constellation of low Earth orbit satellites or medium Earth orbit satellites.

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