Shared radio access network methods and apparatus

Abstract

A method of data communication includes operating a first interface of a channelizer for transmitting a transmit channel to and receiving a first data stream from a wideband radio; operating a second interface of the channelizer to exchange information with distributed unit (DU) functions of multiple network operators, wherein the operating the second interface includes: de-channelizing the first data stream received from the wideband radio into multiple channel streams, wherein each of the multiple channel streams is provided to a corresponding DU function of the DU functions of the multiple network operators; and channelizing multiple second data streams received from the DU functions by multiplexing according to a scheme into the transmit channel that is transmitted over the first interface to the wideband radio.

Description

SHARED RADIO ACCESS NETWORK METHODS AND APPARATUSCROSS-REFERENCE TO RELATED APPLICATION[0011 The application is a continuation and claims priority to U.S. Provisional Application No. 63 / 563,206, filed on March 8, 2025, the disclosure of which is hereby incorporated by reference herein its entirety.TECHNICAL FIELD

[0002] The present document relates to digital communication.BACKGROUND

[0003] Due to an explosive growth in the number of wireless user devices and the amount of wireless data that these devices can generate or consume, current wireless communication networks are fast running out of bandwidth to accommodate such a high growth in data traffic and provide high quality of service to users.

[0004] Various efforts are underway in the telecommunication industry' to come up with next generation of wireless technologies that can keep up with the demand on performance of wireless devices and networks. Many of those activities involve situations in which a large number of user devices may be served by a network.SUMMARY

[0005] This document discloses techniques that may be used by wireless networks to achieve several operational improvements. In particular, embodiments of a radio access network transmission tower are disclosed. In one advantageous aspect, multiple network operators may be able to share the resources of the transmission tower to provide wireless connectivity to user devices.

[0006] In one example aspect, a method of data communication, comprises operating a first interface of a channelizer for transmitting a transmit channel to and receiving a first data stream from a wideband radio: operating a second interface of the channelizer to exchange information with distributed unit (DU) functions of multiple network operators, wherein the operating the second interface includes de- channclizing the first data stream received from the wideband radio into multiple channel streams, wherein each of the multiple channel streams is provided to a corresponding DU function of the DU functions of the multiple network operators: and channelizing multiple second data streams received fromthe DU functions by multiplexing according to a scheme into the transmit channel that is transmitted over the first interface to the wideband radio.

[0007] In yet another aspect, a method of wireless communication, performed by one or more processors of a distributed unit (DU) in a wireless communication system, comprises configuring the one or more processors to perform a DU functionality forN radio access networks (RANs), wherein N is a positive integer; implementing a scheduling function by the one or more processors, wherein the scheduling function generates uplink and downlink schedules for transmission in the N RANs according to a configuration in which at least some transmission resources of the N RANs arc shared among each other according to a shared RAN scheme, and wherein at least some of the N RANs are operated by different network operators.

[0008] In yet another example aspect, an apparatus for digital communications comprising at least one processor and a transceiver is disclosed. The transceiver is configured to transmit or receive digital communication under control of the at least one processor, and the at least one processor is configured to implement one or more of the above-described methods.

[0009] In yet another example aspect, the above-described methods are embodied in the form of computer readable medium that stores processor-executable code for implementing the method.

[0010] In yet another example aspect, a data communication system comprising a plurality of distributed units (DUs) of multiple network operators, a wideband radio, and a channclizcr is disclosed. The channelizer is configured to de-channelize a first data stream received from the wideband radio into multiple channel streams and is configured to channelize multiple second data streams received from the plurality of DUs into a transmit channel that is transmitted over to the wideband radio, wherein each of the multiple channel streams is provided to a corresponding DU of the plurality of DUs of the multiple network operators, and wherein the multiple second data streams are channelized by multiplexing the multiple second data streams according to a scheme into the transmit channel.

[0011] These, and other, features are described in this document.DESCRIPTION OF THE DRAWINGS

[0001] FIG. 1 shows an example communication network.

[0002] FIG. 2 shows a simplified example of a wireless communication system in which uplink and downlink transmissions are performed.

[0003] FIG. 3 shows an example of a cellular transmission tower carrying multiple antennas.

[0004] FIG. 4 depicts examples of resource sharing performed on the network-side.

[0005] FIG. 5 depicts an example of a transmission tower allowing resource sharing.

[0006] FIG. 6 shows an example of an antenna sharing configuration.

[0007] FIG. 7 shows an example of spectrum utilization by different networks.

[0008] FIG. 8 shows multiplexing options implemented in shared networks.

[0009] FIG. 9 shows an example of a unified RAN network.

[0010] FIG. 10 shows an example of a unified RAN network.

[0011] FIG. 11 is an example of protocol stack resource sharing in a network.

[0012] FIGS. 12A-12B show flowcharts for example methods of data communication.

[0013] FIG. 13 shows an example of a transmit chain or a receive chain of a transceiver apparatus.

[0014] FIG. 14 shows a configuration of a transmission tower example.

[0015] FIG. 15 shows an example of a Luneburg antenna with adjustable input feeds.

[0016] FIG. 16 shows an example of a Luneburg antenna with mechanically adjustable input feed locations.

[0017] FIG. 17 shows an example of precoding in a Luneburg antenna-based transmission system.

[0018] FIG. 18 show s an example of a hardware platform.

[0019] FIGS. 19A-19D are flowcharts for example methods of facilitating digital communication.DETAILED DESCRIPTION

[0020] To make the purposes, technical solutions and advantages of this disclosure more apparent, various embodiments are described in detail below with reference to the drawings. Unless otherwise noted, embodiments and features in embodiments of tire present document may be combined with each other.

[0021] Section headings are used in the present document to improve readability of the description and do not in any way limit the discussion or the embodiments to the respective sections only. Furthennore, certain standard-specific terms are used for illustrative purpose only, and the disclosed techniques are applicable to any wireless communication systems.

[0022] 1. Introduction - wireless communication environment examples

[0023] Tire wireless or time-variant nature of the communication channel poses several challenges in design a transmission protocol suitable for ireless communication scenarios. These days, users expect their wireless devices to work everywhere and in a variety of mobile or stationary situations.

[0024] The relative movement of transmitters and receivers with respect to each other cause signal distortions such as varying channel delay, Doppler and / or angular spread, signal degradation due to ground clutter, sea clutter, and so on. Another example of signal degradation is flat fading in which an entire channel occupied by a transmission signal will experience fading or attenuation that may be relatively constant across the channel. In practice, a transmission scheme may need to be designed to fitwithin a certain link budget, maximum power constraint, or linearity of electronics used for transmitting or receiving signals.

[0025] 2. Example wireless systems

[0026] FIG. 1 shows an example of a wireless communication system 100 in which a transmitter device 102 transmits signals to a receiver 104. The signals may undergo various wireless channels and multipaths, as depicted. Some reflectors such as buildings and trees may be static, while others such as cars, may be moving scatterers. The transmitter device 102 may be, for example, a user device, a mobile phone, a tablet, a computer, or another Internet of Tilings (loT) device such as a smartwatch, a camera, and so on. The receiver device 104 may be a network device such as the base station. The signals transmitted from the base station to the transmitter 102 may experience similar channel degradations produced by static or moving scatterers. The techniques described in the present document may be implemented by the devices in the wireless communication system 100. The terms “transmitter” and “receiver” are simply used for convenience of explanation. As further described herein, depending on the direction of transmission (uplink or downlink), the network station may be transmitting or receiving, and / or the user device may be receiving or transmitting.

[0027] FIG. 2 shows a simplified wireless network to highlight certain aspects of the disclosed technology. A transmitter transmits wireless signals to a receiver in the wireless network. Some transmissions in the network, variously called as downlink or downstream transmissions, a network-side node such as a base station acts as a transmitter of wireless signals and one or more user devices act as the receiver of these wireless signals. For some other transmissions, as depicted in FIG. 2, the direction of transmission may be reversed. Such transmissions are often called uplink or upstream transmissions. For such transmissions, one or more user devices act as transmitters of the w ireless signals and a network-side node such as a base station acts as the receiver of these signals (as depicted in FIG. 2). Other type of transmissions in the network may include device-to-device transmissions, sometimes called direct or sideband transmissions. While tire present document primarily uses the terms “downlink” and “uplink” for the sake of convenience, similar techniques may also be used for other situations in which transmissions in two directions are performed - e.g., inbound, or incoming transmissions that are received by a wireless device and outbound or outgoing transmissions that are transmitted by a wireless device. For example, downlink transmissions may be inbound transmissions for a user device, while outbound transmissions for a network device. Similarly, uplink transmission may be inbound transmissions for a network device while outbound transmissions from a wireless device. Therefore, for some embodiments, the disclosed techniques may also be described using terms such as “inbound” and “outbound”transmission without importing any 3GPP-specific or other wireless protocol-specific meaning to the terms “uplink” and “downlink.”

[0028] In frequency division multiplexing (FDM) networks, the transmissions to a base station and the transmissions from the base station may occupy different frequency bands (each of which may occupy continuous or discontinuous spectrum). In time division multiplexing (TDM) networks, the transmissions to a base station and the transmissions from the base station occupy a same frequency band but are separated in time domain using a TDM mechanism such as time slot-based transmissions.

[0029] FIG. 3 shows an example of a cellular transmission tow er earn ing multiple antennas. In the last 20 years, the wireless communication technology, specifically cellular wireless communication technology, has gone through several generations of protocol standards, 2G. 3G, 4G, and so on to 5G. As a result of such an evolution, newer frequency spectrums are becoming available for wireless communication. All these developments have been causing installation of more and more antennas on existing cellular wireless towers. Accompanying such a crowding of available real estate on a cell tow er, the radio equipment that supports the transmission and reception is also crowding antennas at ground level or higher up. Typically, different network operators own / operate their own separate equipment, while towers may be owned and operated by another entity.

[0030] The continued demand on capacity will only make this problem worse in the future. Specifically, low, and mid band wireless communication (e.g., 700-800 MHz and 2 to 5 GHz), a popular and crowded spectrum, wall see this problem getting worse and w orse unless some technical solution to share spectrum and other resource sharing is proposed.

[0031] FIG. 4 depicts examples of resource sharing performed on the network-side. Tire different sharing techniques are depicted by organization along signal travel paths (top to bottom) and different sharing configurations (left to right). In passive sharing (left side), site sharing may be performed such that tower / antenna is shared, but each operator manages their own base station, eNodeB, backhaul, radio controller and core network. In the backhaul sharing configuration, operators may share backhaul and tower, but otherwise manage their own remaining functional blocks.

[0032] In the active sharing configurations, a dedicated configuration may be such that operators have different core networks, but the remaining functional blocks (radio controller, backhaul, base station and tower / antenna) may be shared.

[0033] FIG. 5 depicts an example of a transmission tow er allowing resource sharing. This configuration is sometimes called multiple operator radio access network, MORAN. In this configuration, all functional elements of a physical site may be shared, such as radio controller function, base station function and antennas. However, spectrum may not be shared and may be used independently by each multiplenetwork operator (MNO) such as MNO A and MNO B in the depicted embodiment. Each operator may manage their own dedicated core networks independent of the other operator(s). One advantage of this configuration is to reduce antenna clutter on the transmission tower. However, one disadvantage of this configuration is that the quality of service (QOS) may be impacted due to shared antenna(s), which may reduce signal strength for each MNO’s use.

[0034] Alternatively, in the configuration depicted in FIG. 5, spectrum sharing may also be performed. Such a configuration may have the advantage of further reducing complexity of deployment. However, this may come at the price of reduced flexibility in spectrum use, which may preclude service differentiation. Spectrum sharing may also be disallowed by government regulations.

[0035] FIG. 6 shows an example of an antenna sharing configuration. In this example, the large vertical structure depicted in the photograph of an actual installation may be an antenna array (such as the Huawei antenna array whose block diagram is inset). The antenna array may have ports connected at the bottom (corresponding to the bottom connector lines for the antenna array in the inset block diagram). The smaller boxes to which the second set of arrows point may be actual radios (operated by possibly different network operators) that connect to the antennas in tire antenna array. The sharing may occur across different “G” technologies, meaning different spectrum bands.

[0036] FIG. 7 shows an example of spectrum utilization by different networks. In the depicted examples, same spectrum may be shared by two different generations of protocol standards, e.g., 4G Long Term Evolution (LTE) and 5G New Radio (NR) standards. The spectrum sharing may occur in time or frequency domain (or both).

[0037] FIG. 8 shows examples of time and frequency domain multiplexing options implemented in shared networks. As shown in the top left, two different resource partitioning for two different example G technologies are depicted. One configuration includes a 15 KHz subcarrier occupying time of a full symbol (Tsymb). The other configuration includes a 30 KHz bandwidth occupying half a symbol. The lower left time-frequency graph shows multiplexing of the transmission configurations. The two multiplexing arrangements on the right show a non-orthogonal arrangement (top) and an arrangement in which the spectra are separated by a guard band (bottom).

[0038] FIG. 9 shows an example of a unified RAN network 901. In the depicted configuration, a wideband antenna (903) may be shared by multiple network operators Nl, N2... NX. Various implementation examples of the wideband antenna (903), e.g., a Luneburg lens configuration, are described in the present document. The wideband antenna 903 can be coupled to a wideband radio 905. Tire wideband antenna 903 may be designed to accommodate different sized antenna elements. In general, antenna elements having a size equal to half the wavelength of a frequency band may be used. Therefore,to accommodate transmissions in different frequency bands (e.g., 1.8, 2 or 5 GHz), different sized antenna elements may be used.

[0039] On the reception side, the wideband radio 905 may receive analog signals from the wideband antenna at different frequencies and with different bandwidth occupancies and may extract a digital signal multiplex representing a digital signal corresponding to the information received by the wideband antenna. On the transmit side, the wideband radio 905 may shape the outgoing signal transmissions to conform to the spectral requirements (e g., spectrum bands and widths of the bands).

[0040] Tire wideband radio 905 can be coupled to a channelizer 907. On the receive side, the channelizer 907 may process the signal multiplex received from the wideband radio and separate out the signal into multiple channels (e.g., multiple channel streams) that are then provided to different network operators N 1 to NX. On the transmit side, the channelizer 907 can receive transmission data from each of the network operators and combine the data into packets that are suitable for transmission by the wideband radio 905. Additional technical solutions that may be implemented by the channelizer 907 are disclosed throughout the present document.

[0041] In tire embodiment 901 depicted in FIG. 9, each network operator may operate their own Distributed Unit (DU) functionality. All the DUs can be further coupled to a corresponding Control Plane (CP) and a user plane (UP) of one or more Central Units (CUs). Accordingly, to the extent that scheduling is performed by each operator’s DU, such scheduling can be performed in a resource pool that is screened off or separate from another resource pool accessed and used by another DU. In this embodiment, although all DUs 911 share path through a same chamrelizer and a same wideband radio 905, the CP and UP resources of each network operator can be assigned and managed separately from each other.

[0042] FIG. 10 shows a RAN network embodiment 1001 in which DUs 1011 may be implemented as logically separate DU for each operator, but as a single DU (with some rule-based individual partitioning). Here, the wideband antenna 1003 and the wideband radio 1005 may be substantially similar to as described in FIG. 9. The channelizer 1007 may be configured to operate according to the DU implementation division among network operators, as is further described in the present document. Additional features of a scheduler that operates in such a shared resource scenario are described in the present document.

[0043] FIGS. 9 and 10 show an example of a protocol stack implementation in a unified RAN network (e.g., 901 or 1001) in which different embodiments are possible for the implementation of network configurations that use a wideband antenna. According to a first embodiment, a common distributed unit DU and channelizer may be used, but separate schedulers may be used. In this embodiment, an exclusive resource route may be provided to logical DUs, independent of other logical DUs. In a secondembodiment, all resources may be routed to a single DU that serves all users (e g. all users across all operators). DU may include, for example, gNodeB functionality including layer 2 processing and CU may include higher layer (sometimes called layer 2.5) and above functionalities (e.g., radio link control RUC processing). DU may perfonu the scheduling of data transmissions for transmissions / receptions through the wideband antenna.

[0044] A DU that operates in the second embodiment can be provided with information (e.g., mapping information) that allows the DU to understand which information (e.g., data) comes from or goes to which operator’s core network. The DU will be able to separate and channelize the data to groupings through the channelizer and transmit / receive through the wideband antenna.

[0045] In some cases, which of the above-discussed embodiments may be used in a particular deployment may be a business-level decision that may depend on computing power and / or other electrical / real estate resources available at an antenna site. Such a configuration may therefore consolidate multiple different computing boxes found at certain cell tower sites into a single computing platform. One advantage of such a configuration is that an integrated scheduler that has visibility into different bandwidth requirements of different network operators may be able to optimize resource utilization across different network operators. For example, one network operator may be primarily servicing business customers who use wireless bandwidth during daytime (office hours) while another network operator maybe primarily servicing residential customers that use wireless bandwidth during evening and night hours. The integrated scheduler implemented in a DU in such a case may be selectively able to assign transmission / reception resources to users of different networks depending on such a time use profile. Such a resource sharing may, for example, occur between different frequency bands. Such a sharing of resources may use some of tire interfacing protocols defined by Open Radio Access Network (ORAN) consortium.

[0046] One advantage of the configurations depicted in FIG. 9 and FIG. 10 is that it may accommodate different granularities at which resources are shared. Here, resources mean uplink spectrum, uplink bandwidth, downlink spectrum, downlink bandwidth, reference signal bandwidth, beams, etc. Furthermore, such usage may be tracked and logged and reported to an accounting server to ensure that accurate billing is performed for resource utilization.

[0047] FIG. 11 is an example of protocol stack in a resource sharing RAN in which dynamic crossoperator carrier aggregation may be performed. Such an aggregation may be used for resource sharing as described in the present document. For example, a network operator may wish to combine two 10 MHz bandwidth spectra separated from each other in the frequency domain and operate them as a single 20 MHz channel by performing carrier aggregation. However, presently, such aggregation is not possibleacross different network operators due to protocol restrictions on the underlying protocol standards such as 3GPP specifications and / or the computing power needed to sustain such cross-operator scheduling in real-time. However, using the disclosed technique, such cross-carrier scheduling and resource sharing is made possible.

[0048] As depicted in FIG. 11, from a UE perspective, a UE may receive from (or may transmit to) one or more transmission points, which can be cell towers (e.g., base stations) configured for resource sharing. The antenna resources at the transmission tower can represent the physical layer resources. At the medium access control (MAC) level, transmission packets for multiple UEs may be multiplexed in different transport channels at a transport block (TB) level. For example, two different UEs being served by two different operators may be handled by a scheduler in a manner that allows MAC layer multiplexing of traffic to / from such UEs. At the higher layer (e.g.. radio link control layer), IP packets to / from core networks of different network operators may be identified using different logical channels (e.g., IP addresses or ports). Here, the MAC layer may be controlled by the DU that has been described in the present document.

[0049] In tire configuration where the UE receives / transmits in a synchronized manner with multiple towers, e.g., for a coordinated multi-point (COMP) configuration, using the DU technology described herein, such COMP may be achieved using different operator’s computing resources. Therefore, crossoperator COMP is possible by controlling the multiplexing and resource allocation at the MAC layer, as performed by a single DU (e.g., called a master DU) described herein.

[0050] Example features of tire channelizer and scheduler functions implemented by some preferred embodiments are as follows.

[0051] Examples of operation of a channelizer

[0052] FIG. 12A shows a flowchart for an example method 1200 of data communication that may be performed in the various network configurations disclosed in the present document. The method 1200 includes operating (1202) a first interface of a channelizer for transmitting a transmit channel to and receiving a first data stream from a wideband radio (e.g., the transmit channel and the first data stream can each be a digital data stream), operating (1204) a second interface of the channelizer to exchange information with distributed unit (DU) functions of multiple network operators, wherein the operating the second interface includes de-channelizing (1206) the first data stream received from the wideband radio into multiple channel streams, wherein each of the multiple channel streams is provided to one (e.g., a corresponding DU function) of the DU functions of the multiple network operators; and channelizing (1208) multiple second data streams received from the DU functions by multiplexing according to a scheme into the transmit channel that is transmitted over the first interface to tire wideband radio.

[0053] In some embodiments, the DU functions (e.g., DUs) of the multiple network operators can be logically grouped as a single DU function (e.g., DU).

[0054] In some embodiments, wherein the DU functions of tire multiple network operators can be logically grouped as separate DU functions.

[0055] In some embodiments, the multiplexing may be performed on a transport block by transport block basis (e.g., performed at a transport block level).

[0056] In some embodiments, the operation of the channelizer may be controlled using a rule-based implementation. For example, the rule may configure a channel stream to ca data traffic of at least two different network operators using a single DU (e.g., single DU function).

[0057] Examples of operation of a scheduler

[0058] FIG. 12B shows a flowchart for an example method 1250 of digital communication (e.g., wireless / data communication). The method 1250 may be performed by a DU described in the present document. The method 1250 includes configuring (1252) the one or more processors to perform a DU functionality of / for N radio access networks (RANs), wherein N is a positive integer and implementing (1254) a scheduling function by the one or more processors, wherein the scheduling function generates uplink and downlink schedules for transmission in the N radio access networks according to a configuration in which at least some transmission resources of the N RANs are shared among each other according to a shared RAN scheme, and wherein at least some of the N RANs are operated by different network operators.

[0059] In some embodiments, the shared RAN scheme defines that a wideband antenna is shared among the N RANs.

[0060] In some embodiments, tire shared RAN scheme defines that a wideband antenna and a wideband radio controller (e.g., wideband radio) are shared among the N RANs.

[0061] In some embodiments, the shared RAN scheme defines that a wideband antenna, a wideband radio controller (e.g., wideband radio) and a distributed unit (DU) function are shared among the N RANs.

[0062] In some embodiments, the shared RAN scheme defines that carriers are shared among the different network operators.

[0063] In some embodiments, implementing a scheduling function comprises implementing a split scheduling function in which at least two separate schedulers cooperatively perform scheduling based on a latency requirement of traffic being scheduled. The separation of scheduling tasks between the two separate schedulers may be based on latency requirements of the communication being scheduled and tire two schedulers may be implemented by splitting between distributed unit and the central unit. In someembodiments, to facilitate spectrum sharing among different network operators, the two schedulers may operate to generate a single schedule that controls traffic of multiple network operators on one or more data streams.

[0064] In some embodiments, the channelizer and / or the scheduler can be configured to be quality of service (QOS) aware. For example, service-level, UE-level decisions about QOS may be available to the scheduler. The scheduler may schedule transmission resources such that the QOS target is met.

[0065] In some embodiments, the channelizer may be configured with target numbers for bitrate, bandwidth, error correction coding, etc. of / for communication between wideband radio and the channelizer based on per network operator, or per network operator group basis. For example, a group of network operators may be assigned a common service level agreement and resources may be equally shared within the group.

[0066] In some embodiments, the channelizer may be informed of (or receives) a decision to route traffic received on a spectrum portion of / for a first network operator to the DU (e.g., DU function) of / for a second, different, network operator. For example, such may be the case when the first network operator may be experiencing a reduced usage in its coverage area and may thus allow the second network operator to use its spectrum. In some embodiments, every / each incoming digital data unit from the wideband radio may include a header or may be transmitted on a separate electrical connection that identifies the corresponding spectrum band or network operator whose data is being carried. A similar arrangement of digital data unit identification may be used for outbound data traffic also. Therefore, when the network (e.g., 901 or 1001) reconfigures spectra of different network operators to be used in a shared manner, such a change in configuration may result in modification of header fields that indicate the underlying traffic.

[0067] 3. Technical advantages of the disclosed technology

[0068] It will be appreciated that the present document describes apparatus and methods for sharing a wideband antenna among multiple network operators. Such a design leads to a compact and lower power antenna and transmission tower than conventional techniques and implementations currently deployed in the industry.

[0069] In some embodiments, radio electronics may be shared among multiple network operators, allowing a physical separation of the electronics and the antennas.

[0070] It will be appreciated that the disclosed techniques may be used to transmit or receive time division duplexing (TDD) or frequency division duplexing (FDD) traffic between networks and user devices.

[0071] In some embodiments, multiple network operators, sometimes called “carriers” (e.g., Verizon, T- Mobile, and AT&T in the US) may be able to use a shared channelizer that receives an entire spectrum that includes licensed spectra of each carrier and be able to digitize and separate out each individual network operator’s traffic. Similarly, on the transmit side, a single shared channelizer may be used to radiate RF signals in different licensed spectra. In some embodiments, the shared channelizer may combine (i.e., channelize) one or more signals, each of the one or more signals earn ing a different individual carrier’s traffic, into a signal to be transmitted (e.g , a baseband signal to be transmitted). Each of the one or more signals earn ing a different individual carrier’s traffic may each be a baseband signal transmitted by each of the different individual carriers, respectively. In some embodiments, the shared channelizer may take a received signal and separate out (i.e., de -channelize) one or more signals, each containing different individual traffic meant for each of the different individual carriers, from the received signal. The received signal may be a baseband signal being received converted, by a wideband radio, from an RF signal being received. In one beneficial aspect, such a shared channelizer will reduce the space requirement and power requirement at transmission towers.

[0072] In some embodiments, shared distributed unit (DU) and / or central unit (CU) may be used among different network operators. Furthennore, such a configuration may have the option to have customized configurations and features for each carrier. For example, in some embodiments, each of the one or more signals carrying a different individual carrier’s traffic may be baseband processed and transmitted by a respective shared distributed unit (DU) prior to channelization into a signal to be transmitted. In some embodiments, each of the one or more signals carrying a different individual carrier’s traffic may be received and baseband processed by a respective shared distributed unit (DU) after de-channelization of a baseband signal being received.

[0073] 3.1 Self-interference suppression examples

[0074] In one advantageous aspect, the use of a single wideband antenna allows implementations to eliminate use of diplexers in FDD systems.

[0075] In another advantageous aspect, tire use of a shared wideband antenna and a shared radio facilitates suppression of adjacent channel interference and spectral spill over compared to current network configurations in which different network operators typically do not coordinate their transmissions.

[0076] In another beneficial aspect, the disclosed implementations can be controlled to provide an even spectral density and provides control over the radiated power in an entire wireless spectrum.

[0077] In another beneficial aspect, the proposed techniques can be used to simplify antenna configuration on cellular towers. For example, techniques may reduce weight, wind shear, power dissipation for a tower.

[0078] In another beneficial aspect, the use of a passive antenna lends itself to prolonged MTBF (mean time between failures) compared with active antennas typically employed in present day wireless networks.

[0079] In another beneficial aspect, wideband antennas allow for an omnidirectional gain and mitigation of cos2(9) effect (also denoted the cosine squared theta effect) in planar array typically used in present- day transmission tower configurations.

[0080] In some embodiments, an array of arrays may be used to further enhance spectral efficiency and spatial resolution. Such a configuration may be used to suppress Inter-sector Interference and enhance sector edge coverage.

[0081] The disclosed techniques are used to reconfigure the towers and redress the way the network operators (sometimes called “carriers”) put together the infrastructure. Currently, cellular towers are designed such that for every carrier it will have a specific antenna for a specific band, and a radio transmitter / receiver for the band. As a result of such a slow evolution of various cellular technologies and protocols, presently, transmission tower designs are inefficient and consume a lot of power. Therefore, many transmission towers are inadequately designed to support the next generation of wireless netw orks in which MU-MIMO and a greater density of wireless device deployment is expected.

[0082] Recently, some companies have proposed using utility poles for cellular transmission and / or reception. However, the space constraint on utility poles is even more pronounced than a dedicated transmission tower.

[0083] In the disclosed embodiments, a single electronic component or equipment can be used to terminate (or radiate) all the spectrum (which may include licensed spectrum of multiple netw ork operators). For example, the spectrum may include various frequency channels near the 600 MHz, 700 MHz, 800 MHz, 2GHz spectral regions. In the disclosed embodiments, a baseband stage is configured to generate a spectrum that covers all these different bands that are supported by each of the carriers, and further configured to receive and process different channels of the spectrum. Furthermore, the baseband stage can be configured by each carrier to transmit and / or receive signals in its own spectral slice.

[0084] In the disclosed embodiments, the baseband processing is shared across all the carriers. The baseband processing may essentially span all the spectrum. On the way to RF radiation, the entire spectrum may be processed and fed through a wide-band antenna (e g., wideband antenna). In variousembodiments, a Vivaldi antenna or a Luneburg lens may be used. The wideband antenna may also be similarly configured to receive the whole spectrum and feed it back for baseband processing.

[0085] Tire baseband processing for the downlink and / or the uplink may use high speed analog-to-digital (A2D) or digital-to-analog (D2A) conversion. These A2D or D2A converters may be configured to operate on the full spectrum, for example, from 600 MHz to 2.6 GHz.

[0086] 3.2 Luneburg antenna examples

[0087] In some embodiments, the wideband antenna may use a Luneburg lens that provides a single antenna that is wideband in coverage and is omnidirectional. One beneficial aspect is that a Luneburg antenna will not have the cosine squared theta effect observed in linear element antennas. In other words, the radiation pattern of this antenna is uniform across all directions because of the shape. In some embodiments, the antenna may be coupled to multiple feeds and eventually create an array that carries traffic for all network operators. The feed itself would be wide band. And then eventually that these feeds may be placed around the Luneburg lens. Different from present day antennas, which are typically linear elements and require physical separation (e.g.. 25 inches or so) to ensure mitigation of interference, because a Luneburg antenna will carry traffic such as for entirety of 600 MHz to 2.6 GHz, the feeds for the Luneburg antenna do not require the same physical separation constraints as the present-day antenna configurations.

[0088] Although triband antennas may be used to carry an entire spectrum, these antennas require halflambda separation between antenna elements depending on the frequency of support. For example, some half-lambda antenna elements may be tuned to 600 MHz, other half-lambda antenna elements may be tuned to 700 MHz, and yet other half-lambda antenna elements may be tuned to a third frequency, thereby resulting in dedicated antennas depending on spectrum of operation. An example apparatus includes a port for the 600 MHz communication, a port for the 700 MHz communication, and the like. Thus, within the same physical package, embodiments may interleave different feed elements that correspond to different bands.

[0089] In the described embodiments, the use of a hemispherical or a spherical omnidirectional wideband antenna such as the Luneburg lens will overcome such a physical separation constraint of antenna elements.

[0090] 3.3 MU-MIMO embodiment examples

[0091] Some embodiments may be configured to implement MIMO with Luneburg antennas or lenses. An array of antenna element could be essentially considered as a configuration in which signals are sampled in the spatial domain. For example, for elements that are separated every half lambda (wavelength of frequency band of transmission), spatial beams may be generated via Fourier transform. Insuch embodiments, the antenna plane generates a field that is then transferred across the aperture to follow a radiation pattern.

[0092] In other words, there is a duality betw een the spatial distribution of the field and the radiation pattern. But via the Luneburg lens, the feeds represent the radiation pattern because an element, in an ideal Luneburg lens, is effectively a delta-time (time difference or time delay) where the feed is started in the direction where the radiation is going to go, because the Luneburg lens converts a spherical wave that is radiated from the feed element into a planar wave. Thus, in these systems, the radiation pattern across the Luneburg sphere represents the actual radiation pattern.

[0093] Some of the described embodiments are sampling the radiation pattern under the practical assumption that the aperture is not infinite, the spherical antenna does not completely cover the entire channel band, and the like. Similarly, the radiation pattern is not described using a delta function but using a jinc function (which is further detailed in Section 3.6). The corresponding implementation would have every feed as a jinc function with a certain radiation pattern based on one or more parameters, e.g., aperture size, and these jinc functions are used to create the beam with the desired beam pattern, spacing, and the like. This paradigm can be extended to the multi-user framework, e.g., in a simple case, each of two feeds can be configured in a different direction with some overlap, with each feed corresponding to a different jinc function, a different spherical wave, etc., thereby providing a MU-MIMO implementation.

[0094] In the described embodiments, the Luneburg antenna is an example of a more general wideband antenna that has minimum coupling between the feeds because the lens itself creates isolation between the feeds, i.e., compared to a regular antenna array where the elements are much closer to each other.However, despite tire isolation provided, calibration and adjustment operations are typically performed to account for any mutual coupling.

[0095] 3.4 Power savings examples

[0096] As discussed earlier, due to its spherical shape, a Luneburg lens has an almost equal gain across its surface (e.g., it does not have the cosine square effect of a flat surface), and this advantageously provides power savings. A 40W port receives 40W; but in the case of a Luneburg antenna, the 40W is equally distributed over the entire (hemi)spherical surface, e.g., the entire 120 degrees, which results in only 3W-5W being needed once the gain of the Luneburg antenna has been factored in. This allows the same effective isotropic radiated power (EIRP) to be achieved by trading off the antenna gain and the power. For example, compared to a regular antenna with 17dB gain using 40W, if we were to use a Luneburg antenna with a 25dB or 27dB gain, then only 4W-5W would be needed to achieve the same EIRP.

[0097] In high-power systems, e.g., systems that require 400W (instead of 40W), the required power can be supported by using multiple pow er amplifiers, each powder amplifier configured to support a different band, and then combined back to multiple filters prior to entering the feed. Alternatively, the number of power amplifiers could be reduced by using Luneburg antennas, each having a higher individual gain and supporting a w ider bandwidth. Again, this would achieve the same EIRP across the whole spectrum.

[0098] Existing wireless communication systems are typically configured to use 2W per MHz, which results in using regular antennas with 17dB gain and matching the maximum EIRP allowed. However, using Luneburg antennas according to tire disclosed embodiments enables the 2W per MHz metric to be reduced because of the higher gains of tire antennas, w hile still supporting multiple bands and tire entire spectrum, as discussed above.

[0099] Embodiments of the disclosed technology enable available space to be utilized more effectively in a pow'er-efficient manner. For example, if a bandwidth of 600 MHz were to be supported, MIMO systems with Luneburg antennas can be implemented. For example, a 4-transmit / 4-receive (4^4) system, an 8x8 system, or a higher antenna system can be deployed based on the band frequency. An example system can be deployed using an 8x4 antenna array or a 4x8 antenna array, with 8 antennas in azimuth and 4 antennas in elevation. Using space-efficient Luneburg antennas, the same aperture can be achieved with fewer elements. For example, a system could support 12 ports across 120 degrees in 3.5 GHz. Furthermore, the width of the jinc function that underlies the feeds can be used to determine the spacing between the antennas. This provides uniform and efficient sampling in the far-field.

[0100] In some embodiments, the disclosed technology can be implemented using the described A2Ds, D2As, power amplifiers, and wideband antennas. Thus, Luneburg antennas can be leveraged in a spaceefficient manner to support MU-MIMO.

[0101] 3.5 Antenna geometric stacking examples

[0102] The described embodiments can be integrated into cooperative multipoint (COMP) systems, which presently use regular antenna arrays that are typically separated by roughly half a meter (based on the typical w avelengths used) to mitigate the harmful effects of coupling between antennas. That is, adjacent antennas in COMP systems are separated by about 25 inches, which can be exploited by adding a Luneburg antenna / lens with roughly the same diameter in between adjacent regular antennas. A Luneburg antenna is a passive component that includes no active electronics, and it could be integrated using connected cable antenna hanging. The passive nature of the Luneburg antenna makes it more resilient than current antennas that rely on extensive electronics, which may fail — requiring both identifying that a failure has occurred and fixing the failure, e.g., replacing the electronic component. Further, the (hemi)spherical shape of the Luneburg antenna is preferable to a panel (typically used by a regularantenna) from a wind-loading perspective. Panels may be subjected to significant wind shear, which is not relevant for an implementation of Luneburg antennas. As such, the disclosed embodiments have a greater mean time between failure (MTBF) metric than that of regular electronics-based antennas.

[0103] Incorporating Luneburg antennas, in accordance with the disclosed embodiments, into existing towers with regular antenna arrays will extend the aperture, increase, and improve the resolution (e.g., for improving the measurement of the angle of arrival), and provide a spectrum multiplier. In some embodiments, vertical stacking of Luneburg antennas, horizontal stacking, or a combination of the two can be implemented. An example is shown in FIG. 14.

[0104] 3.6 Additional Luneburg antenna implementations

[0105] As discussed above, the described embodiments can be implemented using one or more Luneburg antennas. One of the properties of a Luneburg antenna is that the angular direction of the beams is a function of the locations of the input feeds, as seen in FIG. 15.

[0106] FIG. 15 shows an example of a Luneburg antenna with adjustable input feeds. Two input feeds and Y2are set at locationsand ^2- creating beams pointing to angles 0tand 02. Changing the locations along horizontal axis will also change 0j and 02.

[0107] When using a Luneburg antenna, it is possible to adjust the locations of the input feeds, such that non-precoded output beams will be pointing towards the remote devices (e.g., user devices). For this, a Luneburg antenna with mechanically adjustable locations of the input feeds is useful, as shown in the example of FIG. 16. FIG. 16 shows an example of a Luneburg antenna with mechanically adjustable input feeds’ locations. In this example, the Luneburg lens has 27 input feeds which are dual-polarization antennas, arranged in 3 different elevation row s, each row consisting of 9 antennas. In each row, the antenna elements are placed on an azimuth rail and the location of each antenna may be adjusted in azimuth. Similarly, an elevation rail may also be used to adjust the elevation of each beam.

[0108] On top of the mechanical adjustment, further shaping of the radiation pattern of the beams is possible by means of precoding (or postcoding of received signals).

[0109] FIG. 17 illustrates a precoding example for two input streams and two output beams. In some embodiments, the number of signals passed between the precoding (or postcoding) operation and feed inputs (or outputs) of the antenna may be greater than the number of wireless stations (e.g., user devices). For example, multiple signals may be combined via additive or subtractive combination to achieve directionality to / from some wireless stations.

[0110] By feeding each input symbol to all antenna feeds, but with different weights, the transmitted beams may be shaped to maximize the SINR (signal to interference and noise ratio) at each target.Similarly, the received symbols from all antenna feeds, may be processed after applying different weights to them, to maximize the receive SINR.

[0111] Luneburg precoding example

[0112] Two input symbols X1and %2can be precoded with weights Pt creating the two input feeds to the antenna and Y2. In a vector notation, Y = P ■ X, where P is a matrix with elements Pitj .

[0113] Multi-layer multi-beam systems for mobile devices

[0114] For mobile devices, such as the case of a Radio-Access-Network (RAN), the beams may be dynamically generated to point to the directions of a selected set of devices (e g., user devices). In some embodiments, uplink channel measurements are enough to design these beams.

[0115] When using a Luneburg antenna for this purpose, the input feeds may be adjusted to output nonprecoded beams, which are evenly spaced in the angular domain. After precoding, the beams will approximately maximize the SINR at each target device (e.g., user devices).

[0116] Multi-beam precoding

[0117] For an antenna with K input ports, let bk(9~). be a function modeling the kthbeam generated by input ports k = 1, ... , K. as a function of the angle 9. For example, a linear antenna array may be modeled by bk9) = constant and a Luneburg antenna may be modeled by a one -dimensional jinc function, as given by bfc(0) = jinc(u) =where / i (-) is a Bessel function of the first kind, u = ^-sin(9 —kf A is the wavelength and 9kis the center of the desired angular beam.

[0118] For the purpose of precoding N < K different streams of information symbols, define N output ports, which are angular targets, defined by 9L. i = 1, ... , N, where an embodiment may target to focus each stream's energy and avoid interference from other streams.

[0119] Note that, for a Luneburg antenna, it is recommended that 9k= 9k. for k = 1, ... , N and the remaining beams (if any exist), k = N -I- 1, ... , K, are at chosen angles that will meet side-lobes radiation constraints and desired SINR.

[0120] Tire precoder will shape the radiation patterns, such that around any angleL. the energy of output port i is maximized, while the energy of all other ports j = i are minimized. To achieve this, each input symbol X, is fed to all the K input ports after multiplying it with a weight vector. More formally, let P be a K X N weights matrix. Then, the actual K inputs feeding the Luneburg antenna are computed as Y = P ■ X. An example of precoding with two ports was given in FIG. 17. The precoder, P. is computed from amathematical basis derived from Bk(x), the Fourier transform of bk(0), and angular windows around d specifying angular constraints.

[0121] In some embodiments, the output signal comprises a number of signals that is equal or greater than a number of the multiple wireless stations. These signals may be components of the output signal that may represent multiple logical signal streams which may be combined to achieve directionality, e.g., as described with respect to FIG. 17.

[0122] 4. Examples and implementations of the disclosed technology

[0123] FIG. 18 is a block diagram representation of a wireless hardware platform 1800 (or hardware platform 1800) which may be used to implement tire various methods described in the present document. The hardware platform 1800 may be incorporated within a base station or a user device. The hardware platform 1800 includes at least one processor 1802, a memory 1804 (this may be optional and in some cases the memory may be internal to the at least one processor) and a transceiver circuitry 1806. The at least one processor 1802 may execute instructions, e. g., by reading from the memory 1804, and control the operation of the transceiver circuitry 1806 and the hardware platform 1800 to perform tire methods described herein. In some embodiments, the memory 1804 and / or the transceiver circuitry 1806 may be partially or completely contained within the at least one processor 1802 (e.g., same semiconductor package). The transceiver circuitry 1806 may enabled data communication via a wired or a wireless interface.

[0124] FIG. 19A is a flowchart of an example method 1900 of facilitating digital communication. The method 1900 includes, at operation 1902, configuring a transceiver apparatus comprising a transmit chain and a receive chain.

[0125] The method 1900 includes, at operation 1904. providing wireless connectivity to multiple user devices operating in multiple network operators' networks in a multi-user multi -input multi -output configuration.

[0126] FIG. 19B is a flowchart of an example method 1910 of facilitating digital communication. The method 1910 includes, at operation 1912, channelizing a signal to be transmitted. In some embodiments, at operation 1912, channelizing a signal to be transmitted may include combining (i.e., channelizing) multiple signals, such as multiple baseband signals, to be transmitted.

[0127] The method 1910 includes, at operation 1914, converting the channelized signal to an RF signal, and at operation 1916, transmitting the RF signal.

[0128] FIG. 19C is a flowchart of an example method 1920 of facilitating digital communication. The method 1920 includes, at operation 1922, dc-channclizing an RF signal being received.

[0129] The method 1920 includes, at operation 1924, converting the de-channelized signal from RF to a baseband signal. In some embodiments, at operation 1924, converting the de-channelized signal may include converting multiple de-channelized signals, which have been separated out (i.e ., de-channelized) from the RF signal being received, from RF to multiple baseband signals.

[0130] The method 1920 includes, at operation 1926. processing the baseband signal using a multi-user multi -input multi-output (MU MIMO) configuration. In some embodiments, at operation 1926, processing the baseband signal may include processing the multiple baseband signals using a multi-user multi-input multi-output (MU MIMO) configuration.

[0131] FIG. 19D is a flowchart of an example method 1930 of facilitating digital communication. Tire method 1930 includes, at operation 1932, receiving an RF signal.

[0132] The method 1930 includes, at operation 1934. converting the RF signal being received to a baseband signal being received.

[0133] The method 1930 includes, at operation 1936, de-channelizing the baseband signal being received to one or more de-channelized baseband signals being received.

[0134] Tire method 1930 includes, at operation 1938, processing the one or more de-channelized baseband signals being received using a multi-user multi-input multi -output (MU MIMO) configuration.

[0135] The following solutions may be preferably implemented by some embodiments. In the solutions disclosed in the present document, the interfaces may ne implemented as an application programming interface, a hardware interface or a combination of hardware (e.g., one or more processors and a memory) and software.

[0136] 1. A method of data communication (e.g., method 1200 depicted in FIG. 12A), comprising: operating (1202) a first interface of a channelizer for transmitting a transmit channel to and receiving a first data stream from a wideband radio: operating (1204) a second interface of the channelizer to exchange information with distributed unit (DU) functions of multiple network operators, wherein the operating the second interface includes: de-channelizing (1206) the first data stream received from the wideband radio into multiple channel streams, wherein each of the multiple channel streams is provided to a corresponding DU function of the DU functions of the multiple network operators; and channelizing (1208) multiple second data streams received from the DU functions by multiplexing according to a scheme into the transmit channel that is transmitted over tire first interface to the wideband radio.

[0137] 2. The method of solution 1 , wherein the DU functions of the multiple network operators are logically grouped as a single DU function.

[0138] 3. The method of solution 1, wherein the DU functions of the multiple netw ork operators are logically grouped as separate DU functions.

[0139] 4. The method of any of solutions 1-3, wherein the multiplexing is performed at a transport block level.

[0140] 5. The method of any of solutions 1-4, wherein a rule configures a channel stream of the multiple channel streams to carry data traffic of at least two different network operators of the multiple network operators with a single DU function of the DU functions.

[0141] 6. The method of any of solutions 1-5, wherein each of the DU functions are coupled to a corresponding Control Plane (CP) and User Plane (UP) of one or more Central Units (CUs).

[0142] 7. The method of solution 6, wherein resources, of the CP and the UP, of each of the multiple netw ork operators are assigned and managed separately from each other.

[0143] 8. Hie method of solution 1, wherein the corresponding DU is a same single DU function that the each of the multiple channel streams is provided to.

[0144] 9. The method of solution 8, wherein the same single DU function is provided with information to map data to and from each corresponding core network of the multiple network operators.

[0145] 10. The method of solution 1, wherein the channelizer is configured to be quality of service (QoS) aware.

[0146] 11. The method of solution 1, wherein the channelizer is configured w ith target numbers for at least one of a bitrate, a bandwidth, or an error correction coding for communication between the wideband radio and the channelizer based on a per network operator or a per network operator group basis.

[0147] 12. The method of solution 1, wherein the channelizer is informed of a decision to route traffic received on a spectrum portion for a first network operator to a DU function of a second network operator.

[0148] 13. The method of solution 1, wherein each incoming digital data unit from the wideband radio includes a header or is transmitted on a separate electrical connection that identifies a corresponding spectrum band or network operator whose data is being carried.

[0149] 14. Tire method of solution 1, wherein each outgoing digital data unit to the wideband radio includes a header or is transmitted on a separate electrical connection that identifies a corresponding spectrum band or netw ork operator whose data is being carried.

[0150] 15. The method of any of solutions 1-14, wherein the wideband radio is coupled to a wideband antenna configured to transmit a radio frequency (RF) signal to be transmitted and receive an RF signal being received using a multi-user multi-input multi -output (MU MIMO) configuration.

[0151] 16. The method of solution 15, wherein the wideband antenna comprises a spherical Luneburg antenna. In an example, the spherical Luneburg antenna is as shown and described in FIGS. 15-17 and Sections 3.2, 3.5 and 3.6 that detail its various aspects.

[0152] 17. A method of wireless communication (e.g., method 1250 depicted in FIG. 12B), performed by one or more processors of a distributed unit (DU) in a wireless communication system, comprising: configuring (1252) the one or more processors to perform a DU functionality for N radio access networks (RANs), wherein N is a positive integer; implementing (1254) a scheduling function by the one or more processors, wherein the scheduling function generates uplink and downlink schedules for transmission in the N RANs according to a configuration in which at least some transmission resources of the N RANs are shared among each other according to a shared RAN scheme, and wherein at least some of the N RANs are operated by different network operators.

[0153] 18. The method of solution 17, wherein the shared RAN scheme defines that a wideband antenna is shared among the N RANs.

[0154] 19. The method of solution 17, wherein the shared RAN scheme defines that a wideband antenna and a wideband radio controller are shared among the N RANs.

[0155] 20. The method of solution 17, wherein the shared RAN scheme defines that a wideband antenna, a wideband radio controller and a distributed unit (DU) function are shared among the N RANs.

[0156] 21. The method of any of solutions 17-20, wherein the shared RAN scheme defines that carriers are shared among the different network operators.

[0157] 22. The method of any of solutions 18-21, wherein the wideband antenna comprises a spherical Luneburg antenna. In an example, the spherical Luneburg antenna is as shown and described in FIGS. 15- 17 and Sections 3.2, 3.5 and 3.6 that detail its various aspects.

[0158] 23. The method of solution 21, wherein the carriers from at least two of the different network operators are aggregated together. In an example, this solution is depicted in FIG. 11 and described in the corresponding section of the description.

[0159] 24. Tire method of solution 23, wherein the carriers from the at least two of the different network operators are implemented across different cell towers. In an example, this solution is depicted in FIG. 11.

[0160] 25. The method of solution 23, wherein a multiplexing of packets to be transmitted or received over the carriers is performed at a transport block level.

[0161] 26. The method of solution 17, wherein a scheduler of the scheduling function is configured to be quality' of service (QoS) aware.

[0162] 27. The method of solution 17, wherein the implementing the scheduling function comprises implementing a split scheduling function in which at least two separate schedulers cooperatively perform scheduling based on a latency requirement of traffic being scheduled.

[0163] 28. An apparatus for digital communications, comprising at least one processor and a transceiver, wherein the transceiver is configured to transmit or receive digital communication under control of the at least one processor, and wherein the at least one processor is configured to implement a method recited in any of solutions 1 to 27.

[0164] 29. A non-transitory computer readable medium having code stored thereon; the code, upon execution by one or more processors, causing the one or more processors to implement a method recited in any of solutions 1 to 27.

[0165] 30. A data communication system, comprising: a plurality of distributed units (DUs) of multiple network operators; a wideband radio; a channelizer configured to de-channelize a first data stream received from the wideband radio into multiple channel streams, and configured to channelize multiple second data streams received from the plurality of DUs into a transmit channel that is transmitted over to the wideband radio, wherein each of the multiple channel streams is provided to a corresponding DU of the plurality of DUs of the multiple network operators, and wherein the multiple second data streams are channelized by multiplexing the multiple second data streams according to a scheme into the transmit channel. In an example, the network for the data communication system is shown in FIG. 13 and used in method 1200 shown in FIG. 12A. Tire network depicted in FIG. 13 may operate similar to the network depicted in FIG. 9 or FIG. 10.

[0166] 31. The data communication system of solution 30, wherein the plurality of DUs of the multiple network operators are logically grouped as a single DU function.

[0167] 32. The data communication system of solution 30, wherein the plurality of DUs of the multiple network operators are logically grouped as separate DU functions.

[0168] 33. The data communication system of any of solutions 30-32, wherein the multiplexing is performed at a transport block level.

[0169] 34. The data communication system of any of solutions 30-33, wherein a rule configures a channel stream of the multiple channel streams to carry data traffic of at least two different network operators of the multiple network operators with a single DU function of the plurality of DU functions.

[0170] 35. The data communication system of any of solutions 30-34, wherein the wideband radio is coupled to a wideband antenna configured to transmit a radio frequency (RF) signal to be transmitted and receive an RF signal being received using a multi-user multi-input multi-output (MU MIMO) configuration.

[0171] 36. The data communication system of solution 35, wherein the wideband antenna comprises a spherical Luneburg antenna. In an example, the spherical Luneburg antenna is as shown and described in FIGS. 15-17 and Sections 3.2, 3.5 and 3.6 that detail its various aspects.

[0172] In some embodiments, the providing wireless connectivity comprises implementing a split scheduling function in which at least two separate schedulers cooperatively perform scheduling. The separation of scheduling tasks between the two separate schedulers may be based on latency requirements of the communication being scheduled and the two schedulers may be implemented by splitting between distributed unit and the central unit. In some embodiments, to facilitate spectrum sharing among different network operators, the two schedulers may operate to generate a single schedule that controls traffic of multiple network operators on one or more data streams.

[0173] It will be appreciated that the present document provides various methods and techniques for providing wireless connectivity to multiple user devices operating in multiple network operators’ networks in a multi-user multi-input multi-output (MU-MIMO) configuration.

[0174] It will further be appreciated that the disclosed techniques are flexible and may be used in many different communication scenarios such as radio access networks (RANs) for mobile device communication in various frequency bands such as in the mega, giga or tera hertz ranges. In some embodiments, the disclosed techniques may be used in a fixed wireless access scenario in which a base station and / or user devices may be located at relatively stationary locations. Other application scenarios include use of the disclosed techniques using non-terrestrial equipment such as satellites, airborne devices such as airplanes, balloons, drones, etc. Tire communication channel in such cases may comprise aerial- to-ground, ground-to-aerial or ariel-to-ariel communication; underwater acoustic wave communication; deep space communication and so on.

[0175] It will further be appreciated that the present document discloses various techniques that allow multiple network operators to share or pool together resources. In one example configuration, a single channelizer is used to feed or receive from a single wideband radio a digital data stream that represents traffic of all network operators. In another example configuration, scheduler function may be implemented in DUs in either a centralized or a distributed or separated manner. It will be appreciated that the disclosed techniques allow for sharing of transmission resources at every level of the transmission / reception chain, including baseband, radio frequency (spectrum), enabling large bandwidth allocations to users where the bandwidths may comprise licensed spectra of different operators. The scheduler function disclosed in the present document enables scheduling of data in a flexible manner such that user devices from one network operator’s sendee area can use spectrum from another operator simplyby configuring the channelizer and scheduler functions to operate using the disclosed wideband radio and antenna embodiments.

[0176] Tire disclosed and other embodiments, modules and tire functional operations described in this document can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this document and their structural equivalents, or in combinations of one or more of them. The disclosed and other embodiments can be implemented as one or more computer program products, i.e ., one or more modules of computer program instructions encoded on a computer readable medium for execution by, or to control the operation of, a data processing apparatus. The computer readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of matter effecting a machine-readable propagated signal, or a combination of one or more of them. The term ‘"data processing apparatus7’ encompasses all apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. The apparatus can include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them. A propagated signal is an artificially generated signal, e.g.. a machine-generated electrical, optical, or electromagnetic signal, which is generated to encode information for transmission to suitable receiver apparatus.

[0177] A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a standalone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.

[0178] The processes and logic flows described in this document can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0179] Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read -only memory or a random-access memory or both. Tire essential elements of a computer are a processor for perfonning instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. However, a computer need not have such devices. Computer readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g.. internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

[0180] While this patent document contains many specifics, these should not be construed as limitations on the scope of an invention that is claimed or of what may be claimed, but rather as descriptions of features specific to particular embodiments. Certain features that are described in this document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or a variation of a sub-combination. Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results.

[0181] Only a few examples and implementations are disclosed. Variations, modifications, and enhancements to the described examples and implementations and other implementations can be made based on what is disclosed.

Claims

WHAT IS CLAIMED IS:

1. A method of data communication, comprising: operating a first interface of a channelizer for transmitting a transmit channel to and receiving a first data stream from a wideband radio; operating a second interface of the channelizer to exchange information with distributed unit (DU) functions of multiple network operators, wherein the operating the second interface includes: de-channelizing the first data stream received from tire wideband radio into multiple channel streams, wherein each of the multiple channel streams is provided to a corresponding DU function of the DU functions of the multiple network operators; and channelizing multiple second data streams received from the DU functions by multiplexing according to a scheme into the transmit channel that is transmitted over the first interface to the wideband radio.

2. The method of claim 1, wherein the DU functions of the multiple network operators are logically grouped as a single DU function.

3. Tire method of claim 1, wherein the DU functions of the multiple network operators are logically grouped as separate DU functions.

4. The method of claim 3 wherein the multiplexing is perfonned at a transport block level.

5. Tire method of claim 4, wherein a rule configures a channel stream of the multiple channel streams to cany^ data traffic of at least two different network operators of the multiple network operators with a single DU function of the DU functions.

6. The method of claim 5, wherein each of the DU functions are coupled to a corresponding Control Plane (CP) and User Plane (UP) of one or more Central Units (CUs).

7. Tire method of claim 6, wherein resources, of the CP and the UP, of each of the multiple network operators are assigned and managed separately from each other.

8. The method of claim 1, wherein the corresponding DU is a same single DU function that the each of the multiple channel streams is provided to.

9. The method of claim 8, wherein the same single DU function is provided with information to map data to and from each corresponding core network of the multiple network operators.

10. The method of claim 1, wherein the channelizer is configured to be quality of service (QoS) aware.

11. The method of claim 1, wherein the channelizer is configured with target numbers for at least one of a bitrate, a bandwidth, or an error correction coding for communication between the wideband radio and the channelizer based on a per network operator or a per network operator group basis.

12. The method of claim 1, wherein the channelizer is informed of a decision to route traffic received on a spectrum portion for a first network operator to a DU function of a second network operator.

13. The method of claim 1, wherein each incoming digital data unit from the wideband radio includes a header or is transmitted on a separate electrical connection that identifies a corresponding spectrum band or network operator whose data is being carried.

14. The method of claim 1, wherein each outgoing digital data unit to the wideband radio includes a header or is transmitted on a separate electrical connection that identifies a corresponding spectrum band or network operator whose data is being carried.

15. The method of claim 14. wherein the wideband radio is coupled to a wideband antenna configured to transmit a radio frequency (RF) signal to be transmitted and receive an RF signal being received using a multi-user multi-input multi -output (MU MIMO) configuration.

16. The method of claim 15, wherein the wideband antenna comprises a spherical Uuneburg antenna.

17. A method of wireless communication, performed by one or more processors of a distributed unit (DU) in a wireless communication system, comprising: configuring the one or more processors to perform a DU functionality for N radio access networks (RANs), wherein N is a positive integer; implementing a scheduling function by the one or more processors, wherein the scheduling function generates uplink and downlink schedules for transmission in the N RANs according to aconfiguration in which at least some transmission resources of the N RANs are shared among each other according to a shared RAN scheme, and wherein at least some of the N RANs are operated by different network operators.

18. The method of claim 17. wherein the shared RAN scheme defines that a wideband antenna is shared among the N RANs.

19. The method of claim 17, wherein the shared RAN scheme defines that a wideband antenna and a wideband radio controller are shared among tire N RANs.

20. The method of claim 17. wherein the shared RAN scheme defines that a wideband antenna, a wideband radio controller and a distributed unit (DU) function are shared among the N RANs.

21. The method of any of claims 17-20, wherein the shared RAN scheme defines that carriers are shared among the different network operators.

22. The method of claim 21. wherein the wideband antenna comprises a spherical Luneburg antenna.

23. The method of claim 21, wherein the carriers from at least two of the different network operators are aggregated together.

24. The method of claim 23. wherein the carriers from the at least two of the different network operators are implemented across different cell towers.

25. The method of claim 23, wherein a multiplexing of packets to be transmitted or received over the carriers is performed at a transport block level.

26. The method of claim 17. wherein a scheduler of the scheduling function is configured to be quality of service (QoS) aware.

27. The method of claim 17, wherein the implementing the scheduling function comprises implementing a split scheduling function in which at least two separate schedulers cooperatively perfonn scheduling based on a latency requirement of traffic being scheduled.

28. An apparatus for digital communications, comprising at least one processor and a transceiver, wherein the transceiver is configured to transmit or receive digital communication under control of tire at least one processor, and wherein the at least one processor is configured to implement a method recited in any of claims 1 to 27.

29. A non-transitory computer readable medium having code stored thereon; the code, upon execution by one or more processors, causing the one or more processors to implement a method recited in any of claims 1 to 27.

30. A data communication system, comprising: a plurality of distributed units (DUs) of multiple network operators; a wideband radio; a channelizer configured to de-channelize a first data stream received from the wideband radio into multiple channel streams, and configured to channelize multiple second data streams received from the plurality of DUs into a transmit channel that is transmitted over to the wideband radio. wherein each of the multiple channel streams is provided to a corresponding DU of the plurality of DUs of the multiple network operators, and wherein the multiple second data streams are channelized by multiplexing the multiple second data streams according to a scheme into the transmit channel.

31. The data communication system of claim 30, wherein the plurality of DUs of the multiple network operators are logically grouped as a single DU function.

32. The data communication system of claim 30, wherein the plurality of DUs of the multiple network operators are logically grouped as separate DU functions.

33. The data communication system of any of claims 30-32. wherein the multiplexing is performed at a transport block level.

34. The data communication system of any of claims 30-33, wherein a rule configures a channel stream of the multiple channel streams to carry data traffic of at least two different network operators of the multiple network operators with a single DU function of the plurality of DU functions.

35. The data communication system of any of claims 30-34. wherein the wideband radio is coupled to a wideband antenna configured to transmit a radio frequency (RF) signal to be transmitted and receive an RF signal being received using a multi-user multi-input multi -output (MU MIMO) configuration.

36. The data communication system of claim 35, wherein the wideband antenna comprises a spherical Luneburg antenna.

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