Satellite fronthaul lower layer split architecture

Abstract

A radio unit, RU, satellite (900), can be configured to operate in a lower layer split, LLS, non-terrestrial network, NTN. The RU satellite can communicate (1010) a signal with a communication device. The RU satellite can perform (1020) RU processing associated with the signal. The RU satellite can communicate (1030) data with a baseband unit, BBU, satellite, the data being associated with the signal.

Description

[0001] SATELLITE FRONTHAUL LOWER LAYER SPLIT ARCHITECTURE

[0002] TECHNICAL FIELD

[0003] The present disclosure is related to communication systems, entities, network node, and host for satellite fronthaul lower layer split architecture.

[0004] BACKGROUND

[0005] Most satellite communication today is based on proprietary solutions, but that may soon change. Non-terrestrial networks became part of the 3rd Generation Partnership Project (“3GPP”) standard in Release 17, establishing a strong foundation for direct communication between satellites, smartphones, and other types of mass-market user equipment.

[0006] As the rate of adoption of mobile communication technology around the world continues to rise, the goal of using it to provide seamless global coverage to anyone, anywhere, at any time has become increasingly important. This has led to major advances in both terrestrial and nonterrestrial satellite networking technology.

[0007] Smooth interworking and integration of terrestrial network (“TN”) and non-terrestrial network (“NTN”) components is the next logical step on the coverage journey to provide enhanced mobile broadband (“eMBB”) to consumer smartphones (direct-to-smartphone) and Internet of Things (“loT”) use cases.

[0008] A satellite radio access network usually includes the following components: at least one satellite that refers to a space-home platform; a gateway that connects a satellite to a base station or a core network; one or more terminals (referring to user equipment); a feeder link that refers to the link between a gateway and a satellite; and a service link that refers to the link between a satellite and a terminal. The link from gateway to terminal is often called a forward link and the link from terminal to gateway is often called a return link. Depending on the functionality of the satellite in the system, there are two transponder options: bent pipe transponder and regenerative transponder. In a bent-pipe transponder system, a satellite forwards the received signal back to the earth with only amplification and a shift from uplink frequency to downlink frequency. In a regenerative transponder system, a satellite includes on-board processing to demodulate and decode the received signal and regenerate the signal before sending it back to the earth.

[0009] FIG. 1 illustrates an example architecture of a satellite network with bent pipe transponders. A satellite radio access network 100 can include: a gateway 160 that connects a satellite network to a core network; a satellite 150 (e.g., a space-home platform); a terminal 120 (e.g., a wireless device and / or user equipment (“UE”); a feeder link 140 (e.g., a link between the gateway 160 and the satellite 150); and an access link 130 (sometimes referred to as a service link) (e.g., a link between the satellite 150 and the terminal 120). In this example, the gateway 160 connects to a core network via a base station 170. In additional or alternative examples, the gateway 160 connects to the core network via any suitable network node or includes the network node.

[0010] The link from the gateway 160 to terminal 120 is often called a forward link, and the link from the terminal 120 to the gateway 160 is often called a return link. Depending on the functionality of the satellite 150 in the satellite radio access network 100, two transponder options may be considered: a bent pipe transponder and / or a regenerative transponder. When using a bent pipe transponder, a satellite forwards the received signal back to the earth with only amplification and a shift from uplink frequency to downlink frequency. When using a regenerative transponder, a satellite includes on-board processing to demodulate and decode the received signal and regenerate the signal before sending it back to the earth.

[0011] Depending on the orbit altitude, a satellite may be categorized as a low earth orbit (“LEO”) satellite, a medium earth orbit (“MEO”) satellite, or a geosynchronous earth orbit (“GEO”) satellite. A LEO satellite is located at a height ranging from 250 - 1,500 km, with orbital periods ranging from 90 - 120 minutes. A MEO satellite is located at a height ranging from 5,000 - 25,000 km, with orbital periods ranging from 3 - 15 hours. A GEO satellite is located at a height of 35,786 km, with an orbital period of 24 hours.

[0012] A satellite may generate several beams over a given area. The footprint of a beam is usually in an elliptic shape, which has been called a cell. The footprint of a beam is also often referred to as a spotbeam (e.g., spotbeam 110 in FIG. 1). The footprint of a spotbeam may move over the earth surface with the satellite movement or may be earth fixed with some beam pointing mechanism used by the satellite to compensate for its motion. The size of a spotbeam depends on the system design, which may range from tens of kilometers to a few thousands of kilometers.

[0013] Two of the main physical phenomena that affect satellite communications system design are the long propagation delay and Doppler effects. The Doppler effects are especially pronounced for LEO satellites.

[0014] Propagation delay is an important aspect of satellite communications that is different from the delay expected in a terrestrial mobile system. For a bent pipe satellite network (e.g., as the satellite radio access network 100 in FIG. 1), the round-trip delay may, due to the orbit height, range from tens of ms in the case of LEO to several hundreds of ms for GEO. This can be compared to the round-trip delays catered for in a cellular network which are limited to 1 ms. The propagation delay may also be highly variable due to the high velocity of the LEO and MEO satellites and change in the order of 10 - 100 ps every second, depending on the orbit altitude and satellite velocity.

[0015] A second important aspect closely related to the timing, is a Doppler frequency offset induced by the motion of the satellite. The access link may be exposed to Doppler shift in the order of 10 - 100 kHz in sub-6 GHz frequency band and proportionally higher in higher frequency bands. Also, the Doppler is varying, with a rate of up to several hundred Hz per second in the S-band and several kHz per second in the Ka-band.

[0016] SUMMARY

[0017] According to some embodiments, a method of operating a radio unit, RU, satellite, in a lower layer split, LLS, non-terrestrial network, NTN, is provided. The method includes communicating a signal with a communication device. The method further includes performing RU processing associated with the signal. The method further includes communicating data with a baseband unit, BBU, satellite, the data being associated with the signal.

[0018] According to other embodiments, a method of operating a baseband unit, BBU, satellite, in a lower layer split, LLS, non-terrestrial network, NTN, is provided. The method includes communicating first data with a ground-based gateway. The method further includes performing baseband, BB, processing associated with the first data. The method further includes communicating second data with a radio unit, RU, satellite, the second data being associated with the first data.

[0019] According to other embodiments, a method of operating a non-terrestrial network, NTN, that includes a baseband unit, BBU, satellite and a radio unit, RU, satellite is provided. The method includes communicating a signal between the RU-satellite and a communication device. The method further includes performing, by the RU-satellite, RU processing associated with the signal. The method further includes communicating fronthaul data between the RU-satellite and the BBU-satellite. The fronthaul data is associated with the signal. The method further includes performing baseband processing associated with the fronthaul data at the BBU-satellite. The method further includes communicating backhaul data between the BBU-satellite and a ground- based gateway.

[0020] According to other embodiments, a network node, a RU-satellite, a BBU-satellite, a NTN system, a computer program, a computer program product, a host, a system, or a non-transitory computer-readable medium is provided to perform one of the above methods. Certain aspects of these embodiments may provide technical advantages. In some embodiments, power budgets and payload are optimized for different roles. In some examples, the satellite carrying the baseband does not have to be equipped with multiple power amplifiers for the access link, therefore more power and payload volume can be allocated for computation parts. In additional or alternative examples, the satellite carrying the radio unit will have less of its payload for computation, which means more volume and power for the power amplifiers and antennas for the access link. In additional or alternative embodiments, lower latency for layer 1 procedures may be enabled. The proposed architecture can enable more advanced transmitter / receiver schemes in comparison to having baseband on ground, as the latency between the computation satellite carrying the baseband and the satellites carrying the radio units is less than the latency to the ground.

[0021] BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate certain nonlimiting embodiments of inventive concepts. In the drawings:

[0023] FIG. 1 is a schematic diagram illustrating an example of a 5thgeneration (“5G”) network;

[0024] FIG. 1 is a schematic diagram illustrating an example of a satellite network with bent pipe transponders;

[0025] FIG. 2 is a schematic diagram illustrating an example of a satellite network with a transparent payload architecture;

[0026] FIG. 3 is a schematic diagram illustrating an example of a satellite network with a regenerative architecture;

[0027] FIG. 4 is a schematic diagram illustrating an example of a NTN system with a base station on board the satellites;

[0028] FIG. 5 is a schematic diagram illustrating an example of a NTN system with a lower layer split over the feeder link;

[0029] FIG. 6 is a schematic diagram illustrating an example of a NTN system with an aggregator satellite;

[0030] FIG. 7 is a schematic diagram illustrating an example of a NTN system with a LLS between a BBU-satellite and a RU-satellite in accordance with some embodiments;

[0031] FIG. 8 is a schematic diagram illustrating an example of a NTN system with multiple satellite clusters in accordance with some embodiments; FIG. 9 is a block diagram illustrating an example of a RU-satellite in accordance with some embodiments;

[0032] FIG. 10 is a block diagram illustrating an example of a BBU-satellite in accordance with some embodiments;

[0033] FIG. 11 is a flow chart illustrating an example of operations performed by a RU-satellite in accordance with some embodiments;

[0034] FIG. 12 is a flow chart illustrating an example of operations performed by a BBU-satellite in accordance with some embodiments;

[0035] FIG. 13 is a block diagram of a communication system in accordance with some embodiments;

[0036] FIG. 14 is a block diagram of a user equipment in accordance with some embodiments;

[0037] FIG. 15 is a block diagram of a network node in accordance with some embodiments; and FIG. 16 is a block diagram of a virtualization environment in accordance with some embodiments.

[0038] DETAILED DESCRIPTION

[0039] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art, in which examples of embodiments of inventive concepts are shown. Inventive concepts may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of present inventive concepts to those skilled in the art. It should also be noted that these embodiments are not mutually exclusive. Components from one embodiment may be tacitly assumed to be present / used in another embodiment.

[0040] A recent branch of satellite constellations targets the low-earth orbit (“LEO”) that promise high data rates and low latencies needed for enhanced mobile broadband (“eMBB”), services that so far were hard to achieve using geostationary (“GEO”) and medium-Earth orbit (“MEO”) non-terrestrial networks (“NTNs”). Those systems are mainly used for satellite broadcasting / television, navigation, and business-to-business data services.

[0041] Integration with satellite networking technologies that can provide coverage in areas that terrestrial networks (“TNs”) cannot reach would help to deliver resilient services to people and businesses currently unserved in both developed and undeveloped parts of the world, bringing significant social and economic benefits. Beyond the benefits NTNs will deliver to smartphones, they will also have the capability to support both industrial and governmental loT devices for verticals such as automotive, health care, agriculture / forestry, utilities, maritime transport, railways, aeronautic / drone sector, national security, and public safety.

[0042] Architectures can be considered where the individual parts of the gNB are split between the satellite and the ground (e.g., the central unit (“CU”) on the ground and the distributed unit (“DU”) on the satellite, or the full baseband (“BBU”) on the ground and only the radio (“RU”) on the satellite).

[0043] There currently exist certain challenges. In some examples, a satellite network has a transparent payload architecture (as depicted in FIG. 2) (also referred to herein as a satellite network with bent pipe transponders or non-regenerative architecture). In a satellite network with a transparent payload architecture, he full fourth generation (“4G”) or fifth generation (“5G”) baseband signal processing is done on the ground and the satellite services as a pure relay node (e.g., a radio frequency (“RF”) reflector) without any data processing capabilities. This limits performance as no signal regeneration or resource optimization / coordination can be made in the satellite.

[0044] A satellite network with regenerative architecture (as depicted in FIG. 3) features signal and packet processing capabilities in the satellite, with the effect of more flexibility / efficiency in resource management / coor dination and therefore higher key performance indicators (“KPIs”). Which part of the processing stack (e.g., of a 5G base-station) is residing at the ground node and which part is put into the satellite (e.g., the functional split) can be subject to optimizations between the requirements on the feeder-link fronthaul interface and system KPIs in terms of, for example, capacity and energy consumption.

[0045] In general, placing more gNB components on the satellite than just the RU eases the requirements on feeder link capacity, but increases the computation and power requirements in the satellite, which might be challenging. A general approach in satellite manufacturing is to minimize the weight of the satellite, since it determines the launch costs, which are significant. This might limit the solar panel area and / or the amount of base station equipment on a satellite.

[0046] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. Various embodiments herein describe different RAN architecture split options. In some embodiments, an architecture is provided based on a radio access network (“RAN”) Low-Layer Split (“LLS”) for the connectivity within / to satellite constellations in a NTN Satellite systems. In additional or alternative embodiments, different options for fronthaul interfaces (e.g., those used in terrestrial networks) can be used over intersatellite communication where the baseband and radio are located in separate satellites.

[0047] In some embodiments, a RAN lower layer split is provided in NTN Satellite systems by locating baseband and radio units in separate satellites.

[0048] In additional or alternative embodiments, routing of fronthaul traffic between satellites in a satellite cluster is provided.

[0049] In additional or alternative embodiments, routing of fronthaul traffic between satellite clusters is provided.

[0050] In additional or alternative embodiments, routing of backhaul traffic from one satellite cluster to another is provided.

[0051] In additional or alternative embodiments, fronthaul load sharing between satellites carrying the radio units is enabled.

[0052] In additional or alternative embodiments, multiple transmission and reception point (“multi-TRP”) from two or more satellites are provided.

[0053] A NTN system can include a ground station on Earth that can be connected to the TN and a core network component, such as a 5G core. The ground station can connect to a satellite via a feeder link. The feeder link is a transport link and, depending on whether the baseband processing is done in space or on the ground, the feeder link may carry backhaul or fronthaul traffic.

[0054] FIG. 4 illustrates an example of a NTN system 400 in which the satellites 450a-b each include a base station (e.g., gNB). Each satellite 450a-b can provide an access link to one or more communication devices within a footprint of a spotbeam 410a-b provided by the satellites 450a-b. An inter-satellite link (“ISL”) 480 provides an interface between the satellites 450a-b. A feeder link 440 between a gateway 460 and the satellite 450a includes backhaul traffic. In this example, core network (“CN”) components and / or functionality are included in the gateway 460.

[0055] FIG. 5 illustrates an example of a NTN system 500 in which the satellites 550a-b each include radio units. As in FIG. 4, each satellite 450a-b can provide an access link to one or more communication devices within a footprint of a spotbeam 510a-b provided by the satellites 550a- b and an ISL 580 provides an interface between the satellites 550a-b. However, in contrast to FIG. 4, a feeder link 540 between a gateway 560 and the satellite 550a includes fronthaul traffic.

[0056] The NTN system 500 can be referred to as a NTN with a lower layer split (“LLS”) over a feeder link. In this example, a baseband node and CN components and / or functions are on the ground while radio units are onboard the satellites. For the deployment of satellites in space, an advantageous topology is to have groups of satellites (cluster) that are anchored to an aggregator satellite via inter satellite links. The aggregator satellite is connected to the ground station via a feeder link. In some examples, such an arrangement can be used to do spatial multiplexing to / from a user terminal (“UT”) (e.g., a communication device or a user equipment) on the ground and in that way increase the capacity to / from the UT on the ground.

[0057] FIG. 6 illustrates an example of a NTN system 600 with an aggregator satellite 650. In contrast to FIGS. 4-5, only some of the satellites (e.g., non-aggregator satellites 652a-b) can provide an access link to one or more communication devices within the footprint of their corresponding spotbeam 610a-b. An ISL 680 can provide an interface between the aggregator satellite 650 and the non-aggregator satellites 652a-b. As a result, communication between a gateway 660 and a communication device with one of the spotbeams 610a-b may travel via a feeder link 640, ISL 680, and a spot beam 610a-b. In this example, the gateway 660 is illustrates as including BBU and CN components and / or functions. In additional or alternative examples, baseband node and CN components and / or functions are on the ground while radio units are onboard the satellites.

[0058] Various embodiments herein propose including baseband units and radio units in different satellites.

[0059] FIG. 7 illustrates an example of a NTN system 700 in which a cluster of satellites includes an aggregator satellite 750 (also referred to herein as a baseband unit satellite (“BBU-satellite”)) includes baseband functionality and radios are placed in non-aggregator satellites 752a-d (also referred to herein as radio unit satellites (“RU-satellites”)). The aggregator satellite 750 has a feeder link 740 to a gateway 760 (also referred to herein as a ground station). A split between baseband unit and radio unit can be referred to as a LLS and open-RAN LLS (“O-LLS”) refers to a standardized version of such a split, which can be implemented in the NTN system 700.

[0060] An ISL 780 between the aggregator BBU-satellite 750 and each of the RU-satellites 752a- d in the cluster is provided wirelessly (e.g., optically). In some examples, the ISL 780 supports an interface variant of the fronthaul interfaces. A switch / router function can be used for routing the fronthaul traffic to the individual satellites in the cluster.

[0061] The RU-satellites 752a-d may have a switch / routing function such that based on some identification in the incoming packets from the BBU- satellite 750, packets can be routed over an ISL 782 to another RU-satellite to be further processed in a destination RU-satellite.752a-d. This functionality can enable load sharing between RU-satellites 752a-d. Furthermore, it can be useful to route the fronthaul traffic via another RU-satellite 752a-d. As illustrated in FIG. 7, this can include using the ISL 780 to the upper left RU-satellite 752a to send fronthaul to the down left RU-satellite 752c via the routing function in the upper left RU-satellite 752a (and the ISL 782).

[0062] As illustrated in FIG. 7, the NTN system 700 includes a single cluster of five satellites. However, a NTN can include any number of clusters of satellites and each cluster can include any number of satellites. As the BBU-satellite will have to support one wireless interface for each RU-satellite in its cluster, different payload and power requirements may produce clusters including different numbers of RU-satellites. Also, the RU-satellites may be deployed in different orbital planes than the BBU-satellite. In this example, it may be required that the wireless interface supports tracking as the satellites will move with respect to each other. In other examples, the RU-satellites may he on the same orbital plane and altitude as the BBU- satellite such that the requirement for wireless interface tracking is drastically reduced.

[0063] FIG. 8 illustrates an example of a NTN system 800 includes two satellite clusters 810a-b. A switch / router in a BBU-satellite of a first satellite cluster 810a can be used to route the backhaul from the feeder link to another BBU-satellite in a second satellite cluster 810b (e.g., a neighbor satellite constellation) via an ISL interface 892. Depending on the payload and power requirement of the BBU-satellite, it may be possible to connect each cluster with a different number of other clusters. The endpoint of these other clusters may he in the same orbit of the BBU-satellite (requiring minimal tracking) or in different orbits (requiring more advanced tracking).

[0064] FIG. 8 further illustrates an example of an ISL interface 890 between a BBU-satellite in the first satellite cluster 810a to a RU-satellite in a second satellite cluster 810b. The ISL interface 890 can enable beamforming capabilities of one satellite cluster to be managed from different base bands (e.g., different BBU-satellites). Although FIG. 8 only illustrates a single ISL interface 890 between a BBU-satellite and a RU-satellite, each BBU-satellite can be connected to any number of RU-satellites in other satellite clusters.

[0065] FIG. 8 further illustrates an example of an ISL interface 880 between RU-satellites belonging to different clusters. This can enable routing of fronthaul traffic between different satellite clusters 810a-b and can improve handover feasibility between satellite clusters. Although FIG. 8 only illustrates a single ISL interface 880 between two RU-satellites, each RU- satellite can be connected to any number of RU-satellites in other satellite clusters.

[0066] In some embodiments, Common Public Radio Interface (“CPRI”) can be used for the LLS fronthaul interface for the ISLs (e.g., ISLs 780, 782, 880, 890, and 892 of FIGS. 7-8). Using CPRI can include using a standardized CPRI interface (e.g., with a so-called PHY-RF split). With CPRI most of the RF processing can be done in the RU-satellite and most of the PHY layer baseband processing can be done in the BBU-satellite.

[0067] The baseband function in the BBU-satellite can include all the radio protocol functionalities and the PHY part can split after / before the IFFT / FFT according to the transmit direction. Time-domain IQ samples can be sent per carrier and antenna stream assembled into TDM CPRI frames and transported over the intersatellite link to the RU-satellite(s).

[0068] In a downlink (“DL”) direction, after some digital and analog signal processing the time domain IQ-samples can be frequency converted to the RF-carrier frequency for the service link, amplified and fed to the RU satellite antenna.

[0069] The CPRI protocol can provide support to have cascaded RU-satellites, multipoint, ring and tree, (e.g., it would support the topology between RU-satellites and BBU-satellite that is illustrated in FIG. 7).

[0070] In some embodiments, from a CPRI protocol perspective, the BBU satellite would act as an Radio Equipment Controller (“REC”) while the RU satellites would act as Radio Equipment (“RE”).

[0071] Note that for this option the routing functionality is done based on antenna carrier identifiers (AxC id) or other fields in the CPRI frame instead of fields in an Ethernet or IP packet.

[0072] Evolved CPRI (“eCPRI”) is a protocol developed to carry radio samples, real time control and other information between baseband radio and converter nodes. It is packet based and enables the implementation of low layer splits anywhere within the PHY-layer of the communication system.

[0073] In general, for OFDM-based systems such as NR and LTE, the functional split is done before the IFFT in downlink (meaning symbol mapper and iFFT are placed in different nodes) and after the FFT in uplink. That results in data streams between nodes proportional to the number of spatial streams and bandwidth usage. In other words, the bandwidth usage in fronthaul scales with the real usage of the air interface (service link).

[0074] For an NTN embodiment the eCPRI packets would be sent to / from the BBU-satellite to from the RU-satellite(s). With eCPRI it would be possible to use Ethernet or IP over the ISL to carry the eCPRI packets enabling to use Ethernet or IP protocol for routing / switching as well as QoS traffic steering.

[0075] One realization of the concept is to have frequency domain data represented in complex numbers together with real time control data plus eCPRI specific data assembled into eCPRI packets. As the eCPRI allows to have the split anywhere in the PHY-layer it would also be possible to also send un-encoded data, thus to do modulation encoding / decoding and pre / post processing in the RU-satellite, which is one way to reduce the required bandwidth for fronthaul on the intersatellite link. Such split can of course also be asymmetric such that unecoded data is sent from the BBU-satellite in DL and frequency domain data is sent from the RU-satellite in UL.

[0076] Another example is that beamforming and equalization could be done either in the RU- satellite or in the BBU-satellite dependent on what LLS alternative that is used. In addition, the eCPRI allows to also have the same split as for CPRI, thus backward compatible to CPRI. The same topologies as supported by CPRI is also possible with eCPRI.

[0077] Digital Radio DOT interface (“dRDI”) is an interface that is used between an indoor radio unit (“IRU”) and a radio DOT in a RDS system. dRDI can use compression of time domain samples to reduce the bandwidth to carry FH data. With dRDI the LLS in the BBU-satellite would be the same as with CPRI but there would also be an IRU functionality that would terminate CPRI and use blockfloating point to compress the IQ samples which are the data part in the dRDI datagram where also a header is added. This datagram is the payload into Ethernet frames to be transmitted over the fronthaul link. In addition to this also OAM messages as well as 1588 synchronization frames are also mulitiplexed with the dRDI datagrams and placed into Ethernet frames. The dRDI would also enable to have cascaded or tree topology between the satellites.

[0078] FIG. 9 illustrates an example of a RU-satellite 900. As illustrated, RU-satellite 900 includes processing circuitry 910, memory 920, and communication interface 930. In some embodiments, the RU-satellite includes a network node (e.g., network node 1500) and its corresponding components.

[0079] The processing circuitry 910 may include a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and / or encoded logic operable to provide, either alone or in conjunction with other RU-satellite 900 components, such as the memory 920, to provide RU-satellite 900 functionality.

[0080] The memory 920 may include any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable and / or computer-executable memory devices that store information, data, and / or instructions that may be used by the processing circuitry 910. The memory 920 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions capable of being executed by the processing circuitry 910 and utilized by the RU-satellite 900. The memory 920 may be used to store any calculations made by the processing circuitry 910 and / or any data received via the communication interface 930. In some embodiments, the processing circuitry 910 and memory 920 is integrated.

[0081] In some embodiments, the processing circuitry 910 includes one or more RU processing circuitry 912 (e.g., RF transceiver circuitry). In some examples, the RU processing circuitry 912 can perform RU processing similar to RU processing in terrestrial LLS systems. In some examples, RU processing includes performing an analog-to-digital conversion (“ADC”). In additional or alternative examples, RU processing includes performing a digital-to-analog conversion (“DAC”). In additional or alternative examples, RU processing includes physical (“PHY”) layer processing. In additional or alternative examples, RU processing includes digital signal processing (e.g., filtering, beam forming, equalization, combining, multiple-input- multiple-output (“MIMO”) processing, or multi-user processing).

[0082] The communication interface 930 can include a terrestrial transceiver 932, intersatellite transceiver 934, and one or more antenna 936. The terrestrial transceiver 932 can be configured to communicate (e.g., using antenna 936) a modulated radio frequency (“RF”) signal with a communication device. The intersatellite transceiver 934 can be configured to communicate (e.g., using antenna 936) fronthaul data via an ISL with a BBU-satellite in a satellite cluster (e.g., satellite cluster 810a of FIG. 8) that includes both the BBU-satellite and the RU-satellite 900.

[0083] In some examples, the terrestrial transceiver 932 receives an uplink (“UL”) modulated RF signal from a communication device. The RU processing circuitry 912 can generate fronthaul data from the UL modulated RF signal. Then the intersatellite transceiver 934 can transmit the fronthaul data to a BBU-satellite.

[0084] In other examples, the intersatellite transceiver 934 can receive fronthaul data from a BBU-satellite. The RU processing circuitry 912 can generate a downlink, DL, modulated RF signal from the fronthaul data. The terrestrial transceiver 934 can transmit the DL modulated RF signal to a communication device.

[0085] In some embodiments, the intersatellite transceiver 934 is further configured to communicate with other RU-satellites. In some examples, this can enable the RU-satellite 900 to perform load balancing with other RU-satellites in the same satellite cluster as the RU- satellite 900. In additional or alternative examples, this can enhance the ability of the RU- satellite 900 to perform a handover of a communication device to a RU-satellite in another satellite cluster.

[0086] In additional or alternative embodiments, the intersatellite transceiver 934 is further configured to communicate with BBU-satellites in other satellite clusters. In some examples, this allows the RU-satellite 900 to be controlled and / or receive fronthaul data from BBU- satellites in different satellite clusters.

[0087] FIG. 10 illustrate an example of a BBU satellite 1000. As illustrated, BBU-satellite 1000 includes processing circuitry 1010, memory 1020, and communication interface 1030. In some embodiments, the RU-satellite includes a network node (e.g., network node 1500) and its corresponding components.

[0088] The processing circuitry 1010 may include a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and / or encoded logic operable to provide, either alone or in conjunction with other BBU-satellite 1000 components, such as the memory 1020, to provide BBU-satellite 1000 functionality.

[0089] The memory 1020 may include any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable and / or computer-executable memory devices that store information, data, and / or instructions that may be used by the processing circuitry 1010. The memory 1020 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions capable of being executed by the processing circuitry 1010 and utilized by the BBU-satellite 1000. The memory 1020 may be used to store any calculations made by the processing circuitry 1010 and / or any data received via the communication interface 1030. In some embodiments, the processing circuitry 1010 and memory 1020 is integrated.

[0090] In some embodiments, the processing circuitry 1010 includes one or more BB processing circuitry 1012. In some examples, the BB processing circuitry 1012 can perform BB processing similar to BB processing in terrestrial LLS systems. The communication interface 1030 can include a terrestrial transceiver 1032, intersatellite transceiver 1034, and one or more antenna 1036. The terrestrial transceiver 1032 can be configured to communicate (e.g., using antenna 1036) a data (e.g., backhaul data) with a ground- based gateway. The intersatellite transceiver 1034 can be configured to communicate (e.g., using antenna 1036) fronthaul data via an ISL with a RU-satellite in a satellite cluster (e.g., satellite cluster 810a of FIG. 8) that includes both the BBU-satellite 1000 and the RU-satellite.

[0091] In some examples, the intersatellite transceiver 1034 receives fronthaul data from the RU- satellite associated with UL data from a communication device. The BB processing circuitry 1012 can process the fronthaul data and the terrestrial transceiver 1032 can transmit the backhaul data associated with the UL data to a ground-based gateway.

[0092] In other examples, the terrestrial transceiver 1032 can receive backhaul data from a ground-based gateway. The BB processing circuitry 1012 can generate fronthaul data from the backhaul data and the intersatellite transceiver 1034 can transmit the fronthaul data to a RU- satellite.

[0093] In some embodiments, the intersatellite transceiver 1034 is further configured to communicate with RU-satellites and / or BBU-satellites in another satellite cluster. In some examples, this can enhance the ability of the BBU-satellite 1000 to perform a handover of a communication device to another satellite cluster. In additional or alternative examples, this allows the BBU-satellite 1000 to control and / or communicate backhaul data with satellites in different satellite clusters.

[0094] Operations of the RU satellite 900 (implemented using the structure of FIG. 9) will now be discussed with reference to the flow chart of FIG. 10 according to some embodiments of inventive concepts. For example, modules may be stored in memory 920 of FIG. 9, and these modules may provide instructions so that when the instructions of a module are executed by respective RU-satellite processing circuitry 910, RU-satellite 900 performs respective operations of the flow chart.

[0095] FIG. 11 illustrates an example of operations performed by a RU-satellite 900 (e.g., RU- satellite 752a) in a LLS NTN (e.g., NTN system 700).

[0096] At block 1110, processing circuitry 910 communicates, via communication interface 930, a signal with a communication device.

[0097] At block 1120, processing circuitry 910 performs RU processing associated with the signal. In some embodiments, performing the RU processing associated with the signal includes at least one of: performing analog-to-digital processing; performing digital-to-analog processing; performing a subset of physical, PHY, layer processing; and performing digital signal processing.

[0098] In additional or alternative embodiments, performing the RU processing associated with the signal includes: receiving beamforming coefficient or steering vector from the BBU-satellite; and generating a beamforming schedule associated with the signal based on the beamforming coefficient or steering vector.

[0099] At block 1130, processing circuitry 930 communicates, via communication interface 930, data with a BBU-satellite (e.g., BBU-satellite 750, 1000). The data can be associated with the signal. In some embodiments, the RU-satellite is a first RU-satellite. In some examples, communicating the data with the BBU-satellite includes communicating the data with the BBU- satellite via a second RU-satellite of the NTN and multiple inters atellite links, ISLs.

[0100] In additional or alternative embodiments, the BBU-satellite is a first BBU-satellite. In some examples, communicating the data with the BBU-satellite includes communicating the data with the first BBU-satellite via a second BBU-satellite of the NTN and multiple intersatellite links, ISLs.

[0101] In additional or alternative embodiments, communicating the data with the BBU-satellite comprises communicating fronthaul data with the BBU-satellite via an intersatellite link, ISL, that includes a fronthaul interface.

[0102] In some examples, the RU-satellite includes receiver equipment, RE; the BBU-satellite includes a receiver equipment controller, REC; the fronthaul data includes common public radio interface, CPRI, data, and the fronthaul interface includes a CPRI interface.

[0103] In additional or alternative examples, the RU-satellite includes enhanced receiver equipment, eRE; the BBU-satellite includes an enhanced receiver equipment controller, eREC; the fronthaul data includes enhanced common public radio interface, eCPRI, data; and the fronthaul interface includes an eCPRI interface.

[0104] In additional or alternative examples, the fronthaul data includes digital radio DOT interface, dRDI, data; and the fronthaul interface includes a dRDI interface.

[0105] Although the operations of FIG. 11 are illustrated in a specific order, the operations can be performed in any suitable order. In some embodiments, communicating the signal with the communication device includes receiving an uplink, UL, modulated radio frequency, RF, signal from the communication device. Performing the RU processing associated with the signal includes determining the data from the UL modulated RF signal. Communicating the data with the BBU-satellite comprises transmitting the data to the BBU-satellite via an intersatellite link, ISL. In additional or alternative embodiments, communicating the data with the BBU-satellite includes receiving downlink, DL, data from the BBU-satellite via an intersatellite link, ISL. Performing the RU processing associated with the signal includes modulating the DL data to generate a modulated DL radio frequency, RF, signal. Communicating the signal with the communication device includes transmitting the DL modulated RF signal to the communication device.

[0106] At block 1140, processing circuitry 930 communicates, via communication interface 930, directly with a second RRU-satellite. In some embodiments communicating directly with the second RU-satellite via an intersatellite link, ISL, is used to perform load balancing between the first RU-satellite and a second RU-satellite. In additional or alternative embodiments, communicating directly with the second RU-satellite via an intersatellite link, ISL, is used to perform traffic congestion balancing between a first path between the first RU-satellite and the BBU-satellite and a second path between the second RU-satellite and the BBU-satellite.

[0107] At block 1150, processing circuitry 930 performs a handover of the communication device to a satellite that is part of a different satellite cluster.

[0108] Various operations from the flow chart of FIG. 11 may be optional with respect to some embodiments of RU-satellites and related methods.

[0109] Operations of the BBU satellite 1000 (implemented using the structure of FIG. 10) will now be discussed with reference to the flow chart of FIG. 12 according to some embodiments of inventive concepts. For example, modules may be stored in memory 1020 of FIG. 10, and these modules may provide instructions so that when the instructions of a module are executed by respective BBU-satellite processing circuitry 1010, BBU-satellite 1000 performs respective operations of the flow chart.

[0110] FIG. 12 illustrates an example of operations performed by a BBU-satellite 1000 (e.g., BBU-satellite 750) in a LLS NTN (e.g., NTN system 700).

[0111] At block 1210, processing circuitry 1010 communicates, via communication interface 1030, first data with a ground-based gateway.

[0112] At block 1220, processing circuitry 1010 performs baseband (“BB”) processing associated with the first data.

[0113] At block 1230, processing circuitry 1030 communicates, via communication interface 1030, second data with a RU-satellite (e.g., RU-satellite 752a, 900). The second data can be associated with the first data.

[0114] Although the operations of FIG. 12 are illustrated in a specific order, the operations can be performed in any suitable order. In some embodiments, communicating the second data with the RU satellite includes receiving uplink, UL, data from a communication device via the RU- satellite and an intersatellite link, ISL. Performing the BB processing associated with the first data includes determining the backhaul data from the UL data. Communicating the first data with the ground-based gateway includes transmitting the backhaul data to the ground-based gateway.

[0115] In additional or alternative embodiments, communicating the first data with the ground- based gateway includes receiving downlink, DL, data from the ground-based gateway. Performing the BB processing associated with the first data includes generating fronthaul data based on the DL data. Communicating the second data with the RU satellite includes transmitting the fronthaul data to the RU satellite via an intersatellite link, ISL.

[0116] In additional or alternative embodiments, the RU-satellite is a first RU-satellite.

[0117] Communicating the second data with the RU-satellite includes communicating the second data with the first RU-satellite via a second RU-satellite of the NTN and multiple intersatellite links, ISLs.

[0118] In additional or alternative embodiments, the BBU-satellite is a first BBU-satellite. Communicating the second data with the RU-satellite includes communicating the second data with the RU-satellite via a second BBU-satellite of the NTN and multiple intersatellite links, ISLs.

[0119] In additional or alternative embodiments, the second data includes at least one of: fronthaul data; backhaul data; and control plane fronthaul traffic.

[0120] In additional or alternative embodiments, communicating the first data with the ground- based gateway comprises communicating backhaul data with the ground-based gateway.

[0121] In some examples, the RU-satellite includes receiver equipment, RE; the BBU-satellite includes a receiver equipment controller, REC; the fronthaul data includes common public radio interface, CPRI, data, and the fronthaul interface includes a CPRI interface.

[0122] In additional or alternative examples, the RU-satellite includes enhanced receiver equipment, eRE; the BBU-satellite includes an enhanced receiver equipment controller, eREC; the fronthaul data includes enhanced common public radio interface, eCPRI, data; and the fronthaul interface includes an eCPRI interface.

[0123] In additional or alternative examples, the fronthaul data includes digital radio DOT interface, dRDI, data; and the fronthaul interface includes a dRDI interface.

[0124] At block 1240, processing circuitry 1030 communicates, via communication interface 1030, directly with a second RU-satellite. In some embodiments communicating directly with the second RU-satellite via an intersatellite link, ISL, is used to perform load balancing between the first RU-satellite and a second RU-satellite. In additional or alternative embodiments, communicating directly with the second RU-satellite via an intersatellite link, ISL, is used to perform traffic congestion balancing between a first path between the first RU-satellite and the BBU-satellite and a second path between the second RU-satellite and the BBU-satellite.

[0125] At block 1250, processing circuitry 1030 performs a handover of the communication device to a satellite that is part of a different satellite cluster.

[0126] Various operations from the flow chart of FIG. 12 may be optional with respect to some embodiments of BBU-satellites and related methods.

[0127] In some embodiments, the operations of FIGS. 11-12 can be performed by aNTN system (e.g., NTN system 700) that includes a RU-satellite and a BBU-satellite.

[0128] FIG. 13 shows an example of a communication system 1300 in accordance with some embodiments.

[0129] In the example, the communication system 1300 includes a telecommunication network 1302 that includes an access network 1304, such as a radio access network (RAN), and a core network 1306, which includes one or more core network nodes 1308. The access network 1304 includes one or more access network nodes, such as network nodes 1310a and 1310b (one or more of which may be generally referred to as network nodes 1310), or any other similar 3rd Generation Partnership Project (3GPP) access node or non-3GPP access point. Moreover, as will be appreciated by those of skill in the art, the network nodes 1310 are not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that the network nodes 1310 may include disaggregated implementations or portions thereof. For example, in some embodiments, the telecommunication network 1302 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in the telecommunication network 1302 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in the telecommunication network 1302, including one or more network nodes 1310 and / or core network nodes 1308.

[0130] Examples of an ORAN network node include an open radio unit (O-RU), an open distributed unit (O-DU), an open central unit (O-CU), including an O-CU control plane (O-CU- CP) or an O-CU user plane (O-CU-UP), a RAN intelligent controller (near-real time or non-real time) hosting software or software plug-ins, such as a near-real time RAN control application (e.g., xApp) or a non-real time RAN automation application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). The network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an Al, Fl, Wl, El, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Intents and content-aware notifications described herein may be communicated from a 3GPP network node or an ORAN network node over 3GPP-defmed interfaces (e.g., N2, N3) and / or ORAN Alliance-defined interfaces (e.g., Al, 01). Moreover, an ORAN network node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an 0-2 interface defined by the 0-RAN Alliance. The network nodes 1310 facilitate direct or indirect connection of user equipment (UE), such as by connecting wireless devices 1312a, 1312b, 1312c, and 1312d (one or more of which may be generally referred to as UEs 1312) to the core network 1306 over one or more wireless connections. The network nodes 1310 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 1312a, 1312b, 1312c, and 1312d (one or more of which may be generally referred to as UEs 1312) to the core network 1306 over one or more wireless connections.

[0131] Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 1300 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / or signals whether via wired or wireless connections. The communication system 1300 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0132] The UEs 1312 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with the network nodes 1310 and other communication devices. Similarly, the network nodes 1310 are arranged, capable, configured, and / or operable to communicate directly or indirectly with the UEs 1312 and / or with other network nodes or equipment in the telecommunication network 1302 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunication network 1302. In the depicted example, the core network 1306 connects the network nodes 1310 to one or more hosts, such as host 1316. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 1306 includes one more core network nodes (e.g., core network node 1308) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 1308. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0133] The host 1316 may be under the ownership or control of a service provider other than an operator or provider of the access network 1304 and / or the telecommunication network 1302, and may be operated by the service provider or on behalf of the service provider. The host 1316 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0134] As a whole, the communication system 1300 of FIG. 13 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Micro wave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox. In some examples, the telecommunication network 1302 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 1302 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 1302. For example, the telecommunications network 1302 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC)ZMassive loT services to yet further UEs.

[0135] In some examples, the UEs 1312 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 1304 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 1304. Additionally, a UE may be configured for operating in single- or multi-RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

[0136] In the example, the hub 1314 communicates with the access network 1304 to facilitate indirect communication between one or more UEs (e.g., UE 1312c and / or 1312d) and network nodes (e.g., network node 1310b). In some examples, the hub 1314 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 1314 may be a broadband router enabling access to the core network 1306 for the UEs. As another example, the hub 1314 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 1310, or by executable code, script, process, or other instructions in the hub 1314. As another example, the hub 1314 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 1314 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub 1314 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 1314 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 1314 acts as a proxy server or orchestrator for the UEs, in particular in if one or more of the UEs are low energy loT devices.

[0137] The hub 1314 may have a constant / persistent or intermittent connection to the network node 1310b. The hub 1314 may also allow for a different communication scheme and / or schedule between the hub 1314 and UEs (e.g., UE 1312c and / or 1312d), and between the hub 1314 and the core network 1306. In other examples, the hub 1314 is connected to the core network 1306 and / or one or more UEs via a wired connection. Moreover, the hub 1314 may be configured to connect to an M2M service provider over the access network 1304 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 1310 while still connected via the hub 1314 via a wired or wireless connection. In some embodiments, the hub 1314 may be a dedicated hub - that is, a hub whose primary function is to route communications to / from the UEs from / to the network node 1310b. In other embodiments, the hub 1314 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 1310b, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0138] FIG. 14 shows a UE 1400 in accordance with some embodiments. As used herein, a UE refers to a device capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other UEs. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart device, wireless customer-premise equipment (CPE), vehicle-mounted or vehicle embedded / integrated wireless device, etc. Other examples include any UE identified by the 3rd Generation Partnership Project (3GPP), including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0139] A UE may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to-everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0140] The UE 1400 includes processing circuitry 1402 that is operatively coupled via a bus 1404 to an input / output interface 1406, a power source 1408, a memory 1410, a communication interface 1412, and / or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in FIG. 14. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0141] The processing circuitry 1402 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 1410. The processing circuitry 1402 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general-purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 1402 may include multiple central processing units (CPUs).

[0142] In the example, the input / output interface 1406 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and / or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into the UE 1400. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0143] In some embodiments, the power source 1408 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. The power source 1408 may further include power circuitry for delivering power from the power source 1408 itself, and / or an external power source, to the various parts of the UE 1400 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 1408. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 1408 to make the power suitable for the respective components of the UE 1400 to which power is supplied.

[0144] The memory 1410 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable readonly memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 1410 includes one or more application programs 1414, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 1416. The memory 1410 may store, for use by the UE 1400, any of a variety of various operating systems or combinations of operating systems.

[0145] The memory 1410 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and / or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ The memory 1410 may allow the UE 1400 to access instructions, application programs and the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in the memory 1410, which may be or comprise a device-readable storage medium.

[0146] The processing circuitry 1402 may be configured to communicate with an access network or other network using the communication interface 1412. The communication interface 1412 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 1422. The communication interface 1412 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 1418 and / or a receiver 1420 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 1418 and receiver 1420 may be coupled to one or more antennas (e.g., antenna 1422) and may share circuit components, software or firmware, or alternatively be implemented separately.

[0147] In the illustrated embodiment, communication functions of the communication interface 1412 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented in according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol / intemet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0148] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 1412, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0149] As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0150] A UE, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door / window sensor, a flood / moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a head-mounted display for Augmented Reality (AR) or Virtual Reality (VR), a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and / or software in dependence of the intended application of the loT device in addition to other components as described in relation to the UE 1400 shown in FIG. 14.

[0151] As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and / or measurements, and transmits the results of such monitoring and / or measurements to another UE and / or a network node. The UE may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0152] In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g. by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

[0153] FIG. 15 shows a network node 1500 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged and / or operable to communicate directly or indirectly with a UE and / or with other network nodes or equipment, in a telecommunication network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs), NR NodeBs (gNBs)), O-RAN nodes, or components of an O-RAN node (e.g., intelligent controller, O-RU, O-DU, O-CU). Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units and / or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0154] Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell / multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).

[0155] The network node 1500 includes a processing circuitry 1502, a memory 1504, a communication interface 1506, and a power source 1508. The network node 1500 may be composed of multiple physically separate components (e.g., aNodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 1500 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 1500 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 1504 for different RATs) and some components may be reused (e.g., a same antenna 1510 may be shared by different RATs). The network node 1500 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1500, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 1500. The processing circuitry 1502 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and / or encoded logic operable to provide, either alone or in conjunction with other network node 1500 components, such as the memory 1504, to provide network node 1500 functionality.

[0156] In some embodiments, the processing circuitry 1502 includes a system on a chip (SOC). In some embodiments, the processing circuitry 1502 includes one or more of radio frequency (RF) transceiver circuitry 1512 and baseband processing circuitry 1514. In some embodiments, the radio frequency (RF) transceiver circuitry 1512 and the baseband processing circuitry 1514 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 1512 and baseband processing circuitry 1514 may be on the same chip or set of chips, boards, or units.

[0157] The memory 1504 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable and / or computer-executable memory devices that store information, data, and / or instructions that may be used by the processing circuitry 1502. The memory 1504 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions capable of being executed by the processing circuitry 1502 and utilized by the network node 1500. The memory 1504 may be used to store any calculations made by the processing circuitry 1502 and / or any data received via the communication interface 1506. In some embodiments, the processing circuitry 1502 and memory 1504 is integrated.

[0158] The communication interface 1506 is used in wired or wireless communication of signaling and / or data between a network node, access network, and / or UE. As illustrated, the communication interface 1506 comprises port(s) / terminal(s) 1516 to send and receive data, for example to and from a network over a wired connection. The communication interface 1506 also includes radio front-end circuitry 1518 that may be coupled to, or in certain embodiments a part of, the antenna 1510. Radio front-end circuitry 1518 comprises filters 1520 and amplifiers 1522. The radio front-end circuitry 1518 may be connected to an antenna 1510 and processing circuitry 1502. The radio front-end circuitry may be configured to condition signals communicated between antenna 1510 and processing circuitry 1502. The radio front-end circuitry 1518 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 1518 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1520 and / or amplifiers 1522. The radio signal may then be transmitted via the antenna 1510. Similarly, when receiving data, the antenna 1510 may collect radio signals which are then converted into digital data by the radio front-end circuitry 1518. The digital data may be passed to the processing circuitry 1502. In other embodiments, the communication interface may comprise different components and / or different combinations of components.

[0159] In certain alternative embodiments, the network node 1500 does not include separate radio front-end circuitry 1518, instead, the processing circuitry 1502 includes radio front-end circuitry and is connected to the antenna 1510. Similarly, in some embodiments, all or some of the RF transceiver circuitry 1512 is part of the communication interface 1506. In still other embodiments, the communication interface 1506 includes one or more ports or terminals 1516, the radio front-end circuitry 1518, and the RF transceiver circuitry 1512, as part of a radio unit (not shown), and the communication interface 1506 communicates with the baseband processing circuitry 1514, which is part of a digital unit (not shown).

[0160] The antenna 1510 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 1510 may be coupled to the radio front-end circuitry 1518 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 1510 is separate from the network node 1500 and connectable to the network node 1500 through an interface or port.

[0161] The antenna 1510, communication interface 1506, and / or the processing circuitry 1502 may be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by the network node. Any information, data and / or signals may be received from a UE, another network node and / or any other network equipment. Similarly, the antenna 1510, the communication interface 1506, and / or the processing circuitry 1502 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and / or signals may be transmitted to a UE, another network node and / or any other network equipment.

[0162] The power source 1508 provides power to the various components of network node 1500 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 1508 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 1500 with power for performing the functionality described herein. For example, the network node 1500 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 1508. As a further example, the power source 1508 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0163] Embodiments of the network node 1500 may include additional components beyond those shown in FIG. 15 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and / or any functionality necessary to support the subject matter described herein. For example, the network node 1500 may include user interface equipment to allow input of information into the network node 1500 and to allow output of information from the network node 1500. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 1500.

[0164] FIG. 16 is a block diagram illustrating a virtualization environment 1600 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 1600 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 1600 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an O-2 interface.

[0165] Applications 1602 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment Q400 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein. Hardware 1604 includes processing circuitry, memory that stores software and / or instructions executable by hardware processing circuitry, and / or other hardware devices as described herein, such as a network interface, input / output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 1606 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 1608a and 1608b (one or more of which may be generally referred to as VMs 1608), and / or perform any of the functions, features and / or benefits described in relation with some embodiments described herein. The virtualization layer 1606 may present a virtual operating platform that appears like networking hardware to the VMs 1608.

[0166] The VMs 1608 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1606. Different embodiments of the instance of a virtual appliance 1602 may be implemented on one or more of VMs 1608, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

[0167] In the context of NFV, a VM 1608 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of the VMs 1608, and that part of hardware 1604 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 1608 on top of the hardware 1604 and corresponds to the application 1602.

[0168] Hardware 1604 may be implemented in a standalone network node with generic or specific components. Hardware 1604 may implement some functions via virtualization. Alternatively, hardware 1604 may be part of a larger cluster of hardware (e.g. such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 1610, which, among others, oversees lifecycle management of applications 1602. In some embodiments, hardware 1604 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 1612 which may alternatively be used for communication between hardware nodes and radio units.

[0169] Although the computing devices described herein (e.g., UEs, network nodes, hosts) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and / or software needed to perform the tasks, features, functions and methods disclosed herein. Determining, calculating, obtaining or similar operations described herein may be performed by processing circuitry, which may process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and / or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination. Moreover, while components are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, computing devices may comprise multiple different physical components that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and / or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of any of such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.

[0170] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer- readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer- readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device, but are enjoyed by the computing device as a whole, and / or by end users and a wireless network generally.

Claims

CLAIMS1. A method of operating a radio unit, RU, satellite (900), in a lower layer split, LLS, nonterrestrial network, NTN, the method comprising: communicating (1110) a signal with a communication device; performing (1120) RU processing associated with the signal; and communicating (1130) data with a baseband unit, BBU, satellite, the data being associated with the signal.

2. The method of Claim 1 , wherein communicating the signal with the communication device comprises receiving an uplink, UL, modulated radio frequency, RF, signal from the communication device, wherein performing the RU processing associated with the signal comprises determining the data from the UL modulated RF signal, and wherein communicating the data with the BBU-satellite comprises transmitting the data to the BBU-satellite via an intersatellite link, ISL.

3. The method of Claim 1, wherein communicating the data with the BBU-satellite comprises receiving downlink, DL, data from the BBU-satellite via an inters atellite link, ISL, wherein performing the RU processing associated with the signal comprises modulating the DL data to generate a modulated DL radio frequency, RF, signal, and wherein communicating the signal with the communication device comprises transmitting the DL modulated RF signal to the communication device.

4. The method of any of Claims 1-3, wherein the RU-satellite is a first RU-satellite, and wherein communicating the data with the BBU-satellite comprises communicating the data with the BBU-satellite via a second RU-satellite of the NTN and multiple intersatellite links, ISLs.

5. The method of any of Claims 1-4, wherein the BBU-satellite is a first BBU-satellite, and wherein communicating the data with the BBU-satellite comprises communicating the data with the first BBU-satellite via a second BBU-satellite of the NTN and multiple intersatellite links, ISLs.

6. The method of any of Claims 1-5, wherein communicating the data with the BBU-satellite comprises communicating fronthaul data with the BBU-satellite via an intersatellite link, ISL, that includes a fronthaul interface.

7. The method of Claim 6, wherein the RU-satellite comprises receiver equipment, RE, wherein the BBU-satellite comprises a receiver equipment controller, REC, wherein the fronthaul data comprises common public radio interface, CPRI, data, and wherein the fronthaul interface comprises a CPRI interface.

8. The method of Claim 6, wherein the RU-satellite comprises enhanced receiver equipment, eRE, wherein the BBU-satellite comprises an enhanced receiver equipment controller, eREC, wherein the fronthaul data comprises enhanced common public radio interface, eCPRI, data, and wherein the fronthaul interface comprises an eCPRI interface.

9. The method of Claim 6, wherein the fronthaul data comprises digital radio DOT interface, dRDI, data, and wherein the fronthaul interface comprises a dRDI interface.

10. The method of any of Claims 1-9, wherein the RU-satellite is a first RU-satellite, the method further comprising: communicating (1140) directly with the second RU-satellite via an intersatellite link, ISL, to perform at least one of: load balancing between the first RU-satellite and a second RU-satellite; and traffic congestion balancing between a first path between the first RU-satellite and the BBU-satellite and a second path between the second RU-satellite and the BBU-satellite.

11. The method of any of Claims 1-10, wherein the RU-satellite and the BBU-satellite are part of a first satellite cluster, the method further comprising: performing (1150) a handover of the communication device to a satellite that is part of a second satellite cluster by communicating with the second satellite cluster via an intersatellite link, ISL.

12. The method of any of Claims 1-11, wherein performing the RU processing associated with the signal comprises at least one of: performing analog-to-digital processing; performing digital-to-analog processing; performing a subset of physical, PHY, layer processing; and performing digital signal processing.

13. The method of any of Claims 1-12, wherein performing the RU processing associated with the signal comprises: receiving beamforming coefficient or steering vector from the BBU-satellite; and generating a beamforming schedule associated with the signal based on the beamforming coefficient or steering vector.

14. A method of operating a baseband unit, BBU, satellite (1000), in a lower layer split, LLS, non-terrestrial network, NTN, the method comprising: communicating (1210) first data with a ground-based gateway; performing (1220) baseband, BB, processing associated with the first data; and communicating (1230) second data with a radio unit, RU, satellite, the second data being associated with the first data.

15. The method of Claim 14, wherein communicating the second data with the RU satellite comprises receiving uplink, UL, data from a communication device via the RU-satellite and an intersatellite link, ISL, wherein performing the BB processing associated with the first data comprises determining the backhaul data from the UL data, and wherein communicating the first data with the ground-based gateway comprises transmitting the backhaul data to the ground-based gateway.

16. The method of Claim 14, wherein communicating the first data with the ground-based gateway comprises receiving downlink, DL, data from the ground-based gateway, wherein performing the BB processing associated with the first data comprises generating fronthaul data based on the DL data, and wherein communicating the second data with the RU satellite comprises transmitting thefronthaul data to the RU satellite via an intersatellite link, ISL.

17. The method of any of Claims 14-16, wherein the RU-satellite is a first RU-satellite, and wherein communicating the second data with the RU-satellite comprises communicating the second data with the first RU-satellite via a second RU-satellite of the NTN and multiple intersatellite links, ISLs.

18. The method of any of Claims 14-17, wherein the BBU-satellite is a first BBU-satellite, and wherein communicating the second data with the RU-satellite comprises communicating the second data with the RU-satellite via a second BBU-satellite of the NTN and multiple intersatellite links, ISLs.

19. The method of any of Claims 14-18, wherein the second data comprises at least one of: fronthaul data; backhaul data; and control plane fronthaul traffic.

20. The method of any of Claims 14-19, wherein communicating the first data with the ground-based gateway comprises communicating backhaul data with the ground-based gateway.

21. The method of any of Claims 14-20, wherein the RU-satellite comprises receiver equipment, RE, wherein the BBU-satellite comprises a receiver equipment controller, REC, wherein the fronthaul data comprises common public radio interface, CPRI, data, and wherein the fronthaul interface comprises a CPRI interface.

22. The method of any of Claims 14-20, wherein the RU-satellite comprises enhanced receiver equipment, eRE, wherein the BBU-satellite comprises an enhanced receiver equipment controller, eREC, wherein the fronthaul data comprises enhanced common public radio interface, eCPRI, data, and wherein the fronthaul interface comprises an eCPRI interface.

23. The method of any of Claims 14-20, wherein the fronthaul data comprises digital radioDOT interface, dRDI, data, and wherein the fronthaul interface comprises a dRDI interface.

24. The method of any of Claims 14-23, wherein the RU-satellite is a first RU-satellite, the method further comprising: communicating (1240) directly with the second RU-satellite via an intersatellite link, ISL, to perform at least one of: load balancing between the first RU-satellite and a second RU-satellite; and traffic congestion balancing between a first path between the first RU-satellite and the BBU-satellite and a second path between the second RU-satellite and the BBU-satellite.

25. The method of any of Claims 14-24, wherein the RU-satellite and the BBU-satellite are part of a first satellite cluster, the method further comprising: performing (1250) a handover of the communication device to a satellite that is part of a second satellite cluster by communicating with the second satellite cluster via an intersatellite link, ISL.

26. The method of any of Claims 14-25, wherein performing the baseband, BB, processing associated with the data comprises performing a subset of physical, PHY, layer processing.

27. A method of operating a non-terrestrial network, NTN, (700) that includes a baseband unit, BBU, satellite and a radio unit, RU, satellite, the method comprising: communicating (1110) a signal between the RU-satellite and a communication device; performing (1120), by the RU-satellite, RU processing associated with the signal; communicating (1130, 1210) fronthaul data between the RU-satellite and the BBU- satellite, the fronthaul data being associated with the signal; performing (1220) baseband processing associated with the fronthaul data at the BBU- satellite; and communicating (1230) backhaul data between the BBU-satellite and a ground-based gateway.

28. The method of Claim 27, further comprising any of the operations of Claims 1-26.

29. A radio unit, RU, satellite (900) in a non-terrestrial network, NTN, the RU-satellite comprising: a terrestrial transceiver (932) configured to communicate a signal with a communication device; processing circuitry (910) configured to perform RU processing associated with the signal; an intersatellite transceiver (934) configured to communicate fronthaul data with a baseband unit, BBU, satellite via an intersatellite link, ISL, the fronthaul data associated with the signal.

30. The RU satellite of Claim 29, further configured to perform any of the operations of Claims 2-13.31 A computer program comprising program code or a computer program product comprising a non-transitory storage medium (920) including the program code , the program code to be executed by processing circuitry (910) of a radio unit, RU, satellite (900), whereby execution of the program code causes the RU-satellite to perform any of the operations of Claims 1-13.

32. A baseband unit, BBU, satellite (1000) in a non-terrestrial network, NTN, the BBU- satellite comprising: a terrestrial transceiver (1032) configured to communicate backhaul data with a ground- based gateway; an intersatellite transceiver (1034) configured to communicate fronthaul data with a radio unit, RU, satellite via an intersatellite link, ISL; and processing circuitry (1010) configured to perform baseband, BB, processing associated with the fronthaul data and / or the backhaul data;.

33. The BBU satellite of Claim 32, further configured to perform any of the operations of Claims 15-26.

34. A computer program comprising program code or a computer program product comprising anon-transitory storage medium (1020) including program code, the program code to be executed by processing circuitry (1010) of a baseband unit, BBU, satellite (1000), whereby execution of the program code causes the BBU-satellite to perform any of the operations of Claims 14-26.

35. A non-terrestrial network, NTN, system (700) comprising: a baseband unit, BBU, satellite (750) configured to: wirelessly communicate backhaul data with a ground-based gateway via a feeder link; wirelessly communicate fronthaul data with a radio unit, RU, satellite via an intersatellite link, ISL; and perform baseband, BB, processing on the backhaul data and / or the fronthaul data; the RU satellite (752a) configured to: wirelessly communicate the fronthaul data with the BBU-satellite via the ISL wirelessly communicate a signal with a communication device via an access link; and. perform baseband, RU, processing on the fronthaul data and / or the signal.

36. The NTN of Claim 35, wherein the RU satellite is a first RU satellite, and wherein the ISL is a first ISL, the NTN further comprising: a second RU satellite configured to communicate with the BBU satellite via a second ISL and configured to communicate with the first RU satellite via a third ISL.

37. The NTN of any of Claims 35-36, further configured to perform any of the operations of Claims 1-26.

38. A computer program comprising program code or a computer program product comprising a non-transitory storage medium including program code, the program code to be executed by processing circuitry of a non-terrestrial network, NTN, system (700), whereby execution of the program code causes the NTN system to perform any of the operations of Claims 1-26.

Images