A UE based smart repeater

Abstract

A method for implementing fixed-wireless access (FWA) in a network having a next generation node B (gNB) and at least two FWA devices configured as customer premise equipments (CPEs) includes: providing a user-equipment-based smart repeater (UBSR) for FWA, wherein said UBSR is configured as a network controlled repeater (NCR) hosted by a first CPE; and dynamically splitting at least one of space, time, and frequency communications resources from the gNB into one portion dedicated to the first CPE hosting the UBSR and another portion amplify-forwarded to a second CPE downstream from the first CPE, wherein at least one of i) the second CPE is beyond the coverage area of the gNB, and ii) the second CPE has a blocked line-of-sight path to the gNB. The UBSR performs dual functionalities of a user equipment (UE) and an NCR mobile termination (NCR-MT) under a single UE identity of the UE.

Description

A UE BASED SMART REPEATERBACKGROUND OF THE DISCLOSURE1. Field of the Disclosure

[0001] The present disclosure is related to wireless systems, and relates more particularly to fixed wireless access (FWA) systems.2. Description of Related Art

[0002] Fixed-wireless access (FWA) is a type of communication technology that enables broadband access over wireless mobile network, e g., using a gNB and a FWA device in customer premises, instead of using wired connections such as cable, DSL or fiber, to provide connectivity between two fixed points. FWA service has emerged to be one of the most successful use cases leveraging 5G features such as massive MIMO and higher bandwidth. With the unique ability to reach the customer premises quickly and economically, especially in the rural areas that are un-served or under-served, FWA has generated much interest from network operators.

[0003] Cellular repeaters are widely used in wireless networks to provide coverage extension. 5G New Radio (NR) repeaters, which leverage massive multiple input, multiple output (mMIMO) and beamforming capabilities, can amplify -forward the signal in different spatial directions (i.e., send beams), which results in higher gain and less interference. The network side (i.e., gNB) is responsible for controlling the direction of the incoming and outgoing beams, and therefore a 5G repeater is referred to as Network Controlled Repeater (NCR), the specification for which is standardized in 3GPP TS 38.106.

[0004] FIG. 1 is a diagram illustrating an NCR 101 as part of the overall network, which also includes a donor gNB 102, and a user device 103. The NCR 101, which is located between the donor gNB 102 and the user device 103, comprises two functional portions, namely Network Controlled Repeater Mobile Termination (NCR-MT) 101a and Network Controlled Repeater Forward (NCR-FWD) 101b. NCR-MT 101a is primarily a simplified user equipment (UE) thatreceives the NCR control information from the network, which comprises the beamforming weights, the transmit power, the downlink / uplink switching, etc. NCR-MT 101a traffic has low bandwidth but requires higher reliability. NCR-FWD 101b is the main function block of the repeater, which function block performs amplify-forwarding of the incoming signal, both from the uplink and the downlink. Also shown in FIG. 1 are: control link 104, which is the radio link between the donor gNB 102 and the NCR-MT 101a; backhaul link 105, which is the radio link between the donor gNB 102 and the NCR-FWD 101b; and access link 106, which is the radio link between the NCR-FWD 101b and the user device 103. The Control Link 104 and the Backhaul Link 105 can share the same carrier frequency for in-band control, or use different frequency bands or even different Radio Access Technology (RAT) for out-of-band control. 5G NCR is equipped with at least two phased-array antennas for the backhaul link 105 as well as the access link 106, respectively. As depicted in FIG. 1, the signal for each link is carried by its respective beam.

[0005] With beamforming, the gNB may send the control information to the NCR to configure the access beam dynamically in different directions in different slots to serve a plurality of user devices. In this context, in-band control has clear advantage over out of band control, as in-band control makes it easier for slot boundary alignment of the NCR control information, and it requires less circuitry for control channel reception.

[0006] For coverage improvement and / or coverage extension for areas without fiber (fixed line) access, both IAB and repeater nodes can be used, with each having its own advantage and disadvantages. NR IAB device is highly efficient in terms of spectral efficiency, but introduces additional delay, as IAB is a “regenerative relay”. Radio frequency (RF) repeaters are non- regenerative, and thus introduce minimal latency, but RF repeaters reduce spectral efficiency in the entire cell by actively amplifying signal and noise. The RF repeaters are also a non-negligible source of “longer than expected distance” interference (echo). The RF repeater has significant cost advantages over the IAB device, i.e., the RF repeater has less energy consumption, smaller form factor and less weight for easier deployment.

[0007] Broadband Equity, Access, and Deployment (BEAD) program is a federal government program initiated by the National Telecommunications and Information Administration (NTIA)of United States, which program is designed to provide high-speed broadband internet access across America, especially for unserved and / or underserved rural areas for households, businesses or other broadband-required locations that lack at least 25Mbps downlink and 3 Mbps uplink speed. FWA, which uses the radio network for the final link (often called “the last mile”) between the home / business and the network, has an inherent cost and time-to service advantage over fiber optics, and FWA is an attractive option for BEAD to achieve its ambitious goal of reaching remote homesteads, rural communities or old buildings that physical wired connection is not possible or cost effective, thereby efficiently bridging the current digital divide.

[0008] A typical wireless network that supports FWA services is illustrated in FIG. 2, which shows gNB 202 and three Customer Premises Equipments (CPEs), i.e., CPE 1, CPE 2 and CPE 3, which are in three houses that are geographically separated. Each CPE is equipped with a phase array antenna (i.e., Array 1 for CPE 1, Array 2 for CPE 2, and Array 3 for CPE 3) mounted on the roof of the respective house. The gNB 202 uses beamforming technology to generate 3 separate beams to serve the 3 CPEs in a spatial multiplexing fashion. CPEs normally demand high data rate (in order to be competitive with fiber alternatives), and as a result require good channel conditions, which in turn require a line-of-sight (LOS) condition between the gNB and the CPEs, as shown in FIG. 2. However, LOS condition from the gNB to the CPE is not guaranteed, and LOS condition can be difficult to obtain even with the best network planning. For example, in rural areas, there may be low household density, abundance of tall trees and sometimes hilly terrain with large variations in elevation, which conditions make it nearly impossible to find a cell site to satisfy LOS condition for all households. Adding additional cell sites to improve coverage in such rural areas would be cost prohibitive, since each of the new site would reach only a handful of additional households. In addition to the LOS condition requirement discussed above, FWA implementation in rural areas is additionally challenged by extreme geographical dispersion of houses such that some houses may be beyond the coverage areas of existing cell sites.

[0009] An existing system for providing coverage improvement and / or coverage extension without the need to set up a new cell site is illustrated in FIG. 3, which shows gNB 202 and two CPEs, i.e., CPE 1 and CPE 2, which are in two houses that are geographically separated. The gNB 202 has a direct LOS condition with CPE1 and communicates with CPE1 through beam Bl.However, a direct LOS condition between gNB 202 and CPE2 is prevented by dense trees, and the direct beam B2 is unable to penetrate the foliage without incurring significant loss in signal strength. To overcome this problem, a Reconfigurable Intelligent Surface (RIS) 301, a.k.a., a “smart reflector”, is used in a third location, i.e., the gNB 202 sends beam B2a to the RIS 301, which in turn “reflects” the incoming beam B2a and sends a reflected beam B2b to the CPE 2. Both B2a path and B2b path are direct LOS, and the RIS 301 can further amplify the B2a signal to ensure high signal quality at the CPE 2. In this manner, the lack of LOS condition for the direct path (beam B2) is circumvented by using two LOS paths. This solution can also be used for coverage extension if the CPE2 were to be out of the coverage of the gNB due to distance or blockage. As alternative implementations, the RIS 301 can be replaced with an Integrated Access and Backhaul (IAB), which is a relay, or a Network controlled Repeater (NCR).

[0010] The above-described existing system for providing coverage improvement and / or coverage extension as shown in FIG. 3 has several drawbacks. First, RIS, IAB and NCR are standalone network devices which require their own physical sites and power supplies. Second, both RIS and NCR require separate control channels (wired or in-band / out-of-band wireless) in order to configure the directions of incident beam and departure beam. Third, IAB is a combination of a base station and a UE, thereby presenting a regenerative delay, and IAB is significantly more costly than NCR or RIS. For these reasons, solutions involving RIS, IAB and NCR are too cost prohibitive for operators to serve a handful of users.

[0011] An alternative existing system for providing coverage improvement and / or coverage extension is 5G Sidelink Relay, which was first approved in 3GPP Release 17 and has been subsequently enhanced in 3GPP Releases 18 and 19. The Sidelink Relay leverages the device-to- device (D2D) communication and extends the coverage through a user device acting as a network portal to another remote user device. This technique (which will be referenced as UE- based Sidelink Relay) has several drawbacks, as explained in detail below.

[0012] UE-based Sidelink Relay in 3GPP Releases 18 and 19 is based on sidelink communication (so-called PC5 interface), i.e., a remote UE needs to first establish sidelink channels with the sidelink relay UE in both directions before the relay UE can forward the traffic related to the remote UE. In order to do that, the relay UE needs to support a complete new setof physical sidelink channels (PSBCH, PSCCH, PSSCH, PSFCH) and L3 / L2 protocols in addition to the regular NR channels to the gNB (PBCH, PDCCH, PUCCH, etc.). In addition, UE-based Sidelink Relay in 3GPP Releases 18 and 19 is designed for device-to-vehicle communication, vehicle-to-infrastructure communication, etc., where frequent beam, time, and / or frequency alignment is required, which requirement may be unnecessary for FWA CPE which is stationary.

[0013] The UE-based Sidelink Relay splits the traffic at the Layer 2 (tunnel through the relay UE), and additional privacy protection is required (e g., encryption), which results in additional overhead and processing. In addition, the UE-based Sidelink Relay introduces extra latency since it is a decode-forward (i.e., regenerative) device, i.e., the information has to be received from the gNB leg and re-encoded into the sidelink leg with its own Media Access Control (MAC) layer protocol. Furthermore, the UE-based Sidelink Relay is designed for D2D communication and can be short-ranged.

[0014] Accordingly, there is a need for a system and a method to improve the FWA coverage in a more cost-efficient and way.SUMMARY

[0015] According to an example embodiment of a system and a method according to the present disclosure, a UE Based Smart Repeater (UBSR) for Fixed Wireless Access (FWA) is provided, which UBSR is configured as a Network Controlled Repeater (NCR) hosted by a CPE, and at least one of space, time, and / or frequency communications resources can be dynamically split into one portion going to the hosting CPE and another portion being amplify-forwarded to a remote CPE device downstream.

[0016] According to an example embodiment of a system and a method according to the present disclosure, the UBSR performs the dual responsibilities of a UE and an NCR-MT under a single UE identity, which is used by the gNB to control the NCR-FWD functionality.

[0017] According to an example embodiment of a system and a method according to the present disclosure, the UBSR doesn't require sidelink channels, and the control of the repeater mode isfully in-band in the 5G New Radio (NR) channels.

[0018] According to an example embodiment of a system and a method according to the present disclosure, the UBSR is configured to handle stationary channel conditions and fixed directions to serve the remote UEs.

[0019] According to an example embodiment of a system and a method according to the present disclosure, the UBSR splits the traffic at the radio frequency (RF) signal level (spatial domain or frequency domain multiplexing) and is non-intrusive to the remote UE's content, i.e., the UBSR only controls the gain and the direction of the beam for the remote UE.

[0020] According to an example embodiment of a method and a system according to the present disclosure, the UBSR is configured as an amplify-forward device and doesn't introduce latency, with very little overhead.

[0021] According to an example embodiment of a method and a system according to the present disclosure, the UBSR is configured to provide higher power and longer range in comparison to existing solutions for last mile coverage extension.

[0022] For this application, the following terms and definitions shall apply:

[0023] The term “network” as used herein includes both networks and internetworks of all kinds, including the Internet, and is not limited to any particular type of network or inter-network.

[0024] The terms “first” and “second” are used to distinguish one element, set, data, object or thing from another, and are not used to designate relative position or arrangement in time.

[0025] The terms “coupled”, “coupled to”, “coupled with”, “connected”, “connected to”, and “connected with” as used herein each mean a relationship between or among two or more devices, apparatus, files, programs, applications, media, components, networks, systems, subsystems, and / or means, constituting any one or more of (a) a connection, whether direct or through one or more other devices, apparatus, files, programs, applications, media, components, networks, systems, subsystems, or means, (b) a communications relationship, whether direct orthrough one or more other devices, apparatus, files, programs, applications, media, components, networks, systems, subsystems, or means, and / or (c) a functional relationship in which the operation of any one or more devices, apparatus, files, programs, applications, media, components, networks, systems, subsystems, or means depends, in whole or in part, on the operation of any one or more others thereof.

[0026] The above-described and other features and advantages of the present disclosure will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims.DESCRIPTION OF THE DRAWINGS

[0027] FIG. l is a block diagram illustrating an example of a conventional Network Controlled Repeater (NCR).

[0028] FIG. 2 is a block diagram illustrating an example of a typical wireless network that supports FWA services.

[0029] FIG. 3 is a block diagram illustrating an existing example of using an RIS to circumvent the absence of LOS condition.

[0030] FIG. 4 is a block diagram illustrating an example of a UBSR according to the present disclosure.

[0031] FIG. 5 illustrates an example deployment of UBSR.

[0032] FIG. 6 illustrates an example of using UBSR for coverage extension.

[0033] FIG. 7 illustrates an example of radio distribution function 1 ( RDF1).

[0034] FIG. 8 illustrates an example of radio distribution function 2 ( RDF2).

[0035] FIG. 9 illustrates an example of spatial domain multiplexing of CPE1 and CPE2 layers.

[0036] FIG. 10 illustrates an example of frequency domain multiplexing of CPE1 and CPE2 traffic.

[0037] FIG. 11 illustrates an example of frequency domain multiplexing with guard bands to isolate CPE1 and CPE2.

[0038] FIG. 12 is a signal flow diagram illustrating an example implementation of UBSR.

[0039] FIG. 13 is a block diagram illustrating a gNB sending control information message to the UE functionality of the UBSR.DETAILED DESCRIPTION

[0040] According to an example embodiment of a method and a system according to the present disclosure, a UE-based smart repeater (UBSR) is configured to implement both i) UE functionality (i.e., function as a UE, which can be, e.g., a mobile phone, a computer, or a tablet device), and ii) repeater functionality (i.e., function as a repeater for another UE). FIG. 4 illustrates a network including a UBSR 41, a donor gNB 42, and a downstream CPE 43. The UBSR 41 includes two radio interfaces: i) the radio interface 401a facing the donor gNB 42, which interface 401a comprises the antenna array Al and the radio distribution function 1 (RDF1); and ii) the radio interface 401b facing the downstream CPE 43, which interface 401b comprises the antenna array A2 and the radio distribution function 2 (RDF2). In addition, the UBSR 41 further includes: i) UE functionality module 402, which encompasses the Network Controlled Repeater Mobile Termination (NCR MT) functionality module 402a; and ii) Network Controlled Repeater Forward (NCR FWD) functionality module 403.

[0041] The UBSR 41 shown in FIG. 4 leverages the two radio interfaces (401a, 401b) and performs the dual functionality as a 5G NR Repeater as well as a UE. The radio link 404 between the UBSR 41 and the donor gNB 42 is both an access link (referenced as “Access Link 1”) for the UE functionality and a backhaul link for the Repeater functionality. The radio link 405 between the UBSR 41 and the downstream CPE 43 is an access link (referenced as “Access Link 2”) for the downstream CPE 43. As noted above, the UE functionality module 402 in the UBSR 41 encompasses the NCR MT functionality module 402a, which receives the NCR control information from the donor gNB 42 and controls the NCR FWD functionality module 403 which amplify-forwards the signals in the downlink and uplink directions accordingly.

[0042] An example deployment of UBSR is shown in FIG. 5, which illustrates CPE1 5001, CPE2 5002, gNB 202 and trees blocking the LOS between gNB 202 and CPE2 5002. CPE1 5001 shown in FIG. 5 is a UBSR with two phased-array antennas A-1A 5001a and A-1B 5001b. A-1A 5001a antenna terminates the user traffic and the repeater control information towards CPE15001, and A-1B 5001b antenna amplify-forwards the potentially split space-time-frequency resources from A-1A 5001a antenna to CPE2 5002 via phased array antenna A-2 5002a. CPE25002, which does not have LOS to the gNB 202 (due to the intervening trees), can leverage the repeater functionality of CPE1 5001 to connect with the gNB 202 via LOS paths Bl 5003 and B12 5004. As a result, the signal quality of the CPE2 5002 can be significantly improved compared to the direct, blocked LOS path through the trees (i.e., path B2 shown in FIG. 3).

[0043] In addition to circumventing a blocked LOS path due to obstacle(s) (e.g., trees, buildings, etc.), according to an example embodiment of the present disclosure, the UBSR can be used for coverage extension, an example of which is illustrated in FIG. 6. FIG. 6 illustrates CPE1 6001, CPE2 6002 and gNB 202. CPE1 6001 shown in FIG. 6 is a UBSR with two phased-array antennas A-1A 6001a and A- IB 6001b. CPE2 6002 has a phased-array antenna A-2 6002a. As a UBSR, the CPE1 6001 can amplify -forward the signal both in the downlink as well as in the uplink to enable connectivity (via path Bl 6003 and path B12 6004) between the gNB 202 and the downstream CPE2 6002, even if the downstream CPE2 6002 is beyond the nominal coverage area of the gNB 202 (the coverage area of which is referenced by the dotted line 61 in FIG. 6). This is especially beneficial for situations where the downstream CPE (e.g., CPE2 6002) is geographically isolated with no or low coverage, and it is not economically viable for a standalone solution such as a repeater or an IAB node.

[0044] According to an example embodiment, in the radio interface between the gNB and the UBSR, the Radio Distribution Function 1 (e.g., RDF 1 in interface 401a of FIG. 4) in the UBSR is responsible for splitting the radio resources in the backhaul / access link 1 (e.g., 404 shown in FIG. 4) between the UBSR and the downstream CPE. FIG. 7 illustrates an example of the RDF1, which includes a phased antenna array Al 7001. Also shown in FIG. 7 are 2 sets of beamforming weights, W 1 and W2, which are applied to the antenna array elements. In the example shown in FIG. 7, the signal at the antenna array element interface can be split into two paths, with W1 being applied to the first path and W2 being applied to the second path, then subsequentlycombined into their respective spatial streams, i.e., outputs SI 7002 and S2 7003 shown in FIG. 7. Each set of the beamforming weights W1 or W2 can be dimensioned to support more than one spatial stream in the output SI 7002 or S2 7003. A spatial steam is sometimes referred to as a beam.

[0045] FIG. 8 illustrates an example of the Radio Distribution Function 2 (RDF 2), e.g., RDF 2 in interface 401b (shown in FIG. 4), which includes a phased antenna array A2 8001 and is located between the interface 401a (containing RDF 1) of the UBSR 41 and the downstream CPE 43 (as shown in FIG. 4). The output from the RDF 1 (e.g., RDF 1 of interface 401a shown in FIG. 4) can be re-beamformed through another set of weights, W3, and is directed towards the downstream CPE (e.g., CPE 43 shown in FIG. 4). It should be noted that the S2 signal (which can correspond to S2 7003 shown in FIG. 7) can be amplified by the built-in repeater mode to improve the signal-to-noise ratio of the Access Link 2 (e.g., 405 shown in FIG. 4) for the downlink of the downstream CPE and / or the Backhaul Link (e.g., 404 shown in FIG. 4) for the uplink of the downstream CPE (e.g., 43 shown in FIG. 4). The gain for the uplink and / or the downlink is configured by the gNB (e.g., 42 shown in FIG. 4) through the NCR control information sent to the UE function (e.g., UE functionality module 402 of FIG. 4) of the UBSR (e.g., UBSR 41 shown in FIG. 4).

[0046] According to an example embodiment, by applying the values of the above-described weights Wl, W2, and W3 according to the control information from the gNB, the space-time- frequency resources can be split between the UE functionality of the UBSR and the downstream CPE.

[0047] In an example embodiment, the radio resource from the gNB (e.g., gNB 42 in FIG. 4) can be spatially separated between the USBR (e.g., UBSR 41 in FIG. 4) and the downstream CPE (e.g., CPE 43 in FIG. 4). In one example variant shown in FIG. 9, spatial domain multiplexing is used, wherein identical time-frequency resources are used by the UBSR and the downstream CPE in a multi-user MIMO configuration. The gNB can inform the NCR-MT function of the USBR to configure the weights Wl and W2 such that one or more layers (e.g., 9001 shown in FIG. 9) of the transmission can be destined for the UBSR, whereas the remaining one or more layers (e.g., 9002 shown in FIG. 9) of the transmission can be amplify-forwarded through theNCR-FWD function of the UBSR towards the downstream CPE via the RDF 2 applying weights W3 (which weights are also obtained from the control information of the gNB). By allowing only the layers destined for the downstream CPE to go through the RDF 2, the inter-layer interference can be effectively reduced, thereby leading to better signal quality in the Access Link 2 towards the downstream CPE.

[0048] In another example embodiment shown in FIG. 10, the radio sources between the USBR (e.g., UBSR 41 in FIG. 4) and the downstream CPE (e.g., CPE 43 in FIG. 4) can be shared through frequency domain multiplexing. As shown in FIG. 10, in the RDF1, the weight W1 may be applied to only a portion (e.g., 1001) of the PRB resources, whereas W2 may be applied to the remaining portion (e.g., 1002) of the PRB resources. In RDF2, the PRB resources (e.g., 1002) destined for downstream CPE may be amplify-forwarded by setting the W3 accordingly. The RDF2 may employ a bandpass fdter to only allow the relevant bandwidth that is related to the downstream CPE to go through to reduce unwanted interference to the neighboring sectors (e.g., frequency domain resources used by UBSR will not be amplify-forwarded).

[0049] In another example embodiment shown in FIG. 11, frequency domain multiplexing can be implemented with guard bands provided in time domain (e.g., 1101a) and / or frequency domain (1101b) to isolate the PRB resources destined for the UBSR from the PRB resources destined for the downstream CPE. When the downstream CPE is beyond the coverage of the gNB, in certain circumstances it can be beneficial to handle the propagation delay of the UBSR and the downstream CPE differently to mitigate the inter-symbol or inter-subcarrier interference. For example, in the downlink, the gNB may need to transmit downlink for downstream CPE much earlier than for the UBSR, to overcome the delay in propagation and the repeater internal processing such that the downstream CPE may appear as an in-coverage UE. It can also be beneficial to configure guard bands in the frequency domain to avoid the repeated signal in the out-of-coverage PRB range “bleed” into the in-coverage PRB range for the UBSR.

[0050] In another example embodiment, time domain multiplexing of the radio resources in the gNB / UBSR link between CPE1 (e.g., CPE1 5001 of FIG. 5 configured as the UBSR) and CPE2 (e.g., CPE2 5002 of FIG. 5) may also be used, but this implementation entails latency and resource utilization efficiency impacts.

[0051] According to an example embodiment, the UBSR can be configured to encompass the UE, NCR-MT and NCR-FWD functionalities in a single physical entity. The UBSR can first establish the Access Link 1 (e.g., part of 404 shown in FIG. 4) with the gNB through its UE functionality (e.g., 402 of FIG. 4) by using regular UE signaling procedures. Once the Access Link 1 is established, the UBSR can subsequently establish the Backhaul link (e.g., part of 404 shown in FIG. 4) and the Access Link 2 (e.g., 405 shown in FIG. 4) with the downstream CPE through the NCR functionalities (e.g., NCR MT 402a and NCR FWD 403).

[0052] FIG. 12 is a signal flow diagram illustrating an example implementation of UBSR 41 (as part of a hybrid CPE, e.g., CPE1 5001 of FIG. 5) in a network also including Open Radio Access Network Distributed Unit (O-DU) 2021 (which is part of the gNB), access and mobility management function (AMF) 2022, and downstream CPE 43. Initially, it is assumed the UBSR 41 has the repeater functionality turned off, and the UBSR 41 uses the standard UE procedures to gain access to the network and start the downlink and uplink data traffic between the gNB and the hybrid CPE (comprising UBSR) itself. The first step 1201 comprises implementing, by the USBR 41 in communication with O-DU 2021 (of the gNB), random access channel (RACH) access procedure and radio resource control (RRC) connection for the hybrid CPE. The next step 1202 comprises implementing, by the UBSR 41 in communication with O-DU 2021 and AMF 2022, network access server identifier (NAS-ID) authentication procedure and Security Mode Command (SMC) procedure. Next, in step 1203a, O-DU 2021 sends a UE capability enquiry to the UBSR 41. In response, the UBSR 41 indicates (in step 1203b) to the O-DU 2021 that it supports a built-in repeater mode. Step 1204 comprises implementing, by the UBSR 41 in communication with O-DU 2021 and AMF 2022, protocol data unit (PDU) session establishment procedure. In step 1205, the downlink (DL) and uplink (UL) data traffic for the UE functionality is started between the UBSR 41 (part of the hybrid CPE) and the O-DU 2021 (of the gNB).

[0053] When the O-DU 2021 (of the gNB) receives the repeater capability information from the UBSR 41 in step 1203b, the O-DU 2021 (of the gNB) may treat the UE identity associated with the UBSR (e.g., Cell Radio-Network Temporary Identifier (CRNTI), International Mobile Equipment Identity (IMEI), International Mobile Subscriber Identity (IMSI), etc.) as both a regular UE and an NCR-MT. Accordingly, in step 1206, the O-DU 2021 (of the gNB) sends to the UBSR 41, through in-band communication, the control information for the repeater mode ofthe UBSR. In step 1207, the UBSR 41 subsequently applies the repeater control information (e g., weights Wl, W2 and W3, repeater uplink and downlink gain settings, repeater directions, etc.) and amplify-forwards the Master Information Block (MIB) and / or System Information Block (SIB) information to the downstream UE. Subsequently, the UE procedures are implemented for the downstream CPE 43, including steps 1208, 1209 and 1210. Step 1208 comprises implementing, by the downstream CPE 43 in communication with UBSR 41 and O- DU 2021 (of the gNB), RACH access procedure for the downstream CPE 43. Step 1209 comprises implementing, by the downstream CPE 43 in communication with UBSR 41, O-DU 2021 and AMF 2022, NAS-ID authentication procedure and SMC procedure. Step 1210 comprises implementing, by the downstream CPE 43 in communication with UBSR 41, O-DU 2021 and AMF 2022, PDU session establishment procedure. In step 1211, the DL and UL data traffic for the UE functionality is started between the downstream CPE 43 and the O-DU 2021 (of the gNB) via UBSR 41.

[0054] In the case the UE functionality of the UBSR 41 is no longer needed (e.g., UE detaches), the UBSR 41 shall work fully as a repeater with NCR-MT function and NCR-FWD function activated. Conversely, if the downstream CPE 43 detaches, the NCR-MT and NCR-FWD functionalities may still be activated to maintain MIB / SIB traffic in anticipation of the next access attempt.

[0055] As shown in FIG 13, the gNB 42 can send Control Information 1 (Control Info 1) message to the UE functionality module 402 of the UBSR 41, which message can comprise the beamforming weights for signals going towards the UE 402, as well as the beamforming weights for signals going towards the NCR-FWD 403 and to the downstream UE, the gain settings, slot / symbol to perform transceiver (TRX) switching, etc. The Control Info 1 message can be carried in a Downlink Control Information (DCI) or a Media Access Control (MAC) Control Element (CE) structure and be sent to the UBSR 41 in PDCCH or Physical Downlink Shared Channel (PDSCH) channels. The UE 402 can forward a part of the Control Info 1 message in Control Information 2 (Control Info 2) message to the NCR-FWD 403, wherein the Control Info 2 can comprise the information that is only related to the NCR-FWD 403.

[0056] From a signaling perspective, compared to a standalone repeater, the UBSR 41 doesn’trequire additional authentication for NCR-MT functionality by introducing the repeater mode into the UE capability information. In addition, the UBSR 41 doesn’t require additional circuitry for MT functions such as demodulation and decoding. Furthermore, because the UBSR 41 is located in the same household that subscribes to FWA service, no additional site selection is needed. The above-described characteristics make the UBSR a cost-effective solution in comparison to other solutions such as a standalone repeater, an IAB or an RIS.

[0057] In addition, a network operator can incorporate the UBSR’s repeater capability in the network planning and coverage projection process, such that the network operator can determine in advance which households will benefit the most by deploying the UBSR to improve the signal quality or coverage range or both for other FWA devices. By providing optimal locations for the gNB, the UBSR and downstream CPEs deployed to the respective households, spectral efficiency for the entire network can be maximized. In addition, since the UBSR works partially as a network function (network-controlled repeater) and potentially affects the sector coverage and the connectivity to other user devices, the network operator can i) include the UBSR in the network inventory and topology of network functions, and ii) manages the UBSR’s on-boarding and orchestration processes accordingly.

[0058] According to an example embodiment, when the downstream CPE is another UBSR, the downstream UBSR can use its repeater functionality, and the above-described system and / or technique can be used to support yet another downstream CPE in a daisy-chained fashion to reach CPEs that are even further downstream.

[0059] The example embodiments according to the present disclosure provide a UE-based smart repeater (UBSR) solution for FWA to address problematic deployment issues such as LOS blockage (due to terrain, trees, etc.), thereby enabling coverage improvement and / or coverage extension. The UBSR according to the present disclosure is a new type of CPE with additional responsibility of managing the access link in the repeater mode for the downstream CPEs. The Radio Distribution function 1 (RDF1) implemented as a part of the UBSR provides a novel functionality of splitting the radio signal over the air into digital beam forming streams for the UE host and analog beamforming streams for the repeater.

[0060] To support the novel functionality provided by the present disclosure, 3GPP TechnicalSpecification (TS) 38.106 (regarding 5G Repeater) and TS 38.306 (regarding capability-related signaling for UBSR) need to be modified accordingly.

[0061] Some of the advantage provided by the example embodiments according to the present disclosure include: improved coverage; cost-effective solution for low population density rural areas; and meeting the increased demand from network operators for FWA solutions. The example embodiments of the UBSR solution can leverage better propagation path to reach the end user to improve signal quality. For example, a blocked LOS condition between a base station and a CPE can be circumvented by implementing a UBSR that has an LOS to the base station and an LOS to a downstream CPE. Furthermore, the UBSR according to the present disclosure can extend the range of the existing base station to reach CPEs that are otherwise out of the coverage are. The repeater mode implemented by the UBSR can amply the signal to provide extended coverage. In terms of operating cost, the UBSR according to the present disclosure provides an effective solution for low population density rural areas, which would otherwise require additional base stations that are too costly for a small handful of households. Similarly, it would not be economical to use other coverage expansion solutions such as Integrated Access and Backhaul (IAB), stand-alone Repeater, or Reconfigurable Intelligent Surface (RIS) unit, as these solutions require additional network components, dedicated site selection, power supply and control link installation, etc.

[0062] The UBSR solution according to the present disclosure utilizes the UE functionality to fulfill the need of repeater control, thereby obviating the need for an independent circuitry for Network Controlled Repeater Mobile Termination (NCR-MT) that would be required in the case of a standalone repeater. Because the UBSR solution according to the present disclosure utilizes existing CPE installation, there is no need to find an additional site for a standalone repeater. In addition, the UBSR according to the present disclosure can receive in-band instructions from the gNB to control the beamforming aspects of the repeater functionality, and potentially serve more than one downstream CPE through beam switching in the access link. In the case the downstream CPE is another UBSR, a daisy-chained repeater mode can be implemented such that the gNB can serve remote users even further out into the unserved areas.

[0063] FWA, which is the fastest growing 5G use case, is drawing heavy interest from networkoperators who are interested in cost-effective solutions to support more subscribers. Accordingly, the UBSR according to the present disclosure provides a novel solution to address the cost issue in delivering high-quality broadband connectivity to the “last mile”, especially for rural areas where population is sparse or for areas the LOS coverage in difficult to achieve.

[0064] While the present disclosure has been described with reference to one or more exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. For example, the although the example methods have been described in the context of 5G wireless systems, the disclosure is equally applicable to 4G and / or 6G systems. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment s) disclosed as the best mode contemplated, but that the disclosure will include all embodiments falling within the scope of the appended claims.

[0065] For the sake of completeness, a list of abbreviations used in the present specification is provided below:BEAD — Broadband Equity, Access, and DeploymentCPE - Customer Premises EquipmentCRNTI - Cell Radio Network Temporary IdentifierD2D - Device to DeviceDCI - Downlink Control IndicatorFWA - Fixed Wireless Access gNB - next generation node B (a / k / a gNodeB)IAB - Integrated Access and BackhaulIMEI - International Mobile Equipment IdentityIMSI - International Mobile Subscriber IdentityLOS - Line of SightMAC CE - MAC Control Element mMIMO - massive Multiple Input, Multiple OutputNCR - Network Controlled RepeaterNCR-FWD - Network Controlled Repeater ForwardNCR-MT - Network Controlled Repeater Mobile TerminalNLOS - Non Line of SightPBCH - Physical Broadcast ChannelPDCCH - Physical Downlink Control ChannelPRB - Physical Resource BlockPSBCH - Physical Sidelink Broadcast ChannelPSCCH - Physical Sidelink Control ChannelPSFCH - Physical Sidelink Feedback ChannelPSSCH - Physical Sidelink Shared ChannelPUCCH - Physical Uplink Control ChannelRDF - Radio Signal Distribution FunctionRIS - Reconfigurable Intelligent SurfaceUBSR - UE based Smart Repeater xDSL - Digital Subscriber Line

Claims

CLAIMS:

1. A method for implementing fixed-wireless access (FWA) in a network having a next generation node B (gNB) and at least two FWA devices configured as customer premise equipments (CPEs), comprising: providing a user-equipment-based smart repeater (UBSR) for FWA, wherein said UBSR is configured as a network controlled repeater (NCR) hosted by a first CPE; and dynamically splitting at least one of space, time, and frequency communications resources from the gNB into one portion dedicated to the first CPE hosting the UBSR and another portion amplify-forwarded to a second CPE downstream from the first CPE, wherein at least one of i) the second CPE is beyond the coverage area of the gNB, and ii) the second CPE has a blocked line-of-sight path to the gNB.

2. The method according to claim 1, wherein: the UBSR performs dual functionalities of a user equipment (UE) and an NCR mobile termination (NCR-MT) under a single UE identity of the UE; and the single UE identity of the UE is used by the gNB to control NCR forward (NCR- FWD) functionality of the NCR.

3. The method according to claim 1, wherein: the UBSR comprises i) a first radio interface interfacing with the gNB, and ii) a second radio interface interfacing with the second CPE; and the UBSR performs dual functionality of a user equipment (UE) and a 5G New Radio (NR) NCR.

4. The method according to claim 3, wherein: the first radio interface implements a first radio link which is both an access link for the UE functionality and a backhaul link for a repeater functionality of the 5G NR NCR; and the second radio interface implements a second radio link which is an access link for the second CPE.

5. The method according to claim 4, wherein: the first radio interface comprises i) antenna array elements, and ii) a first radio distribution function which splits radio resources in the first radio link between the UE functionality and the second CPE; and a first set of beamforming weights is applied to signals from a first portion of the antenna array elements forming a first signal path to form a first output signal stream, and second set of beamforming weights is applied to signals from a second portion of the antenna array elements forming a second signal path to form a second output signal stream.

6. The method according to claim 5, wherein: at least the second output signal stream of the second signal path is i) forwarded through the NCR-FWD functionality and ii) applied with a third set of beamforming weights by a second radio distribution function of the second radio interface.

7. The method according to claim 3, wherein: radio resources from the gNB are spatially separated between the UBSR and the second CPE by spatial domain multiplexing, and identical time-frequency resources are used by the UBSR and the second CPE.

8. The method according to claim 3, wherein: radio resources from the gNB are shared through frequency domain multiplexing between the USBR and the second CPE, whereby i) a first beamforming weight is applied to a first portion of specified physical resource blocks (PRB) resources, and ii) a second beamforming weight is applied to a remaining portion of the specified PRB resources.

9. A system for implementing fixed-wireless access (FWA) in a network having a next generation node B (gNB) and at least two FWA devices configured as customer premise equipments (CPEs), comprising: a user equipment (UE) and a network controlled repeater mobile termination (NCR-MT)functionality module under a single UE identity of the UE; and network controlled repeater forward (NCR-FWD) functionality module; wherein said UE, NCR-MT functionality module and NCR-FWD functionality module are parts of a user-equipment-based smart repeater (UBSR) configured as a network controlled repeater (NCR) hosted by the first CPE, and at least one of i) the second CPE is beyond the coverage area of the gNB, and ii) the second CPE has a blocked line-of-sight path to the gNB.

10. The system according to claim 9, wherein at least one of: i) at least one of space, time, and frequency communications resources from the gNB are dynamically split into one portion dedicated to the first CPE hosting the UBSR and another portion amplify-forwarded to the second CPE; and ii) the single UE identity of the UE is used by the gNB to control the NCR-FWD functionality module.

11. The system according to claim 9, wherein: the UBSR further comprises i) a first radio interface interfacing with the gNB, and ii) a second radio interface interfacing with the second CPE; and the UBSR is configured to perform dual functionalities of the UE and a 5G New Radio (NR) NCR.

12. The system according to claim 11, wherein: the first radio interface is configured to implement a first radio link which is both an access link for the UE functionality and a backhaul link for a repeater functionality of the 5G NR NCR; and the second radio interface is configured to implement a second radio link which is an access link for the second CPE.

13. The system according to claim 12, wherein: the first radio interface comprises i) antenna array elements, and ii) a first radio distribution function configured to split radio resources in the first radio link between the UEfunctionality and the second CPE; and a first set of beamforming weights is applied to signals from a first portion of the antenna array elements forming a first signal path to form a first output signal stream, and second set of beamforming weights is applied to signals from a second portion of the antenna array elements forming a second signal path to form a second output signal stream.

14. The system according to claim 13, further comprising: a second radio distribution function of the second radio interface; wherein at least the second output signal stream of the second signal path is i) forwarded through the NCR-FWD functionality and ii) applied with a third set of beamforming weights by the second radio distribution function of the second radio interface.

15. The system according to claim 11, wherein: radio resource from the gNB are spatially separated between the UBSR and the second CPE by spatial domain multiplexing, and identical time-frequency resources are used by the UBSR and the second CPE.

16. The system according to claim 11, wherein: radio resources from the gNB are shared through frequency domain multiplexing between the USBR and the second CPE, whereby i) a first beamforming weight is applied to a first portion of specified physical resource blocks (PRB) resources, and ii) a second beamforming weight is applied to a remaining portion of the specified PRB resources.

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