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WO2024253796A1 - Techniques pour diminuer la latence dans un système d'antenne distribué - Google Patents

Techniques pour diminuer la latence dans un système d'antenne distribué Download PDF

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Publication number
WO2024253796A1
WO2024253796A1 PCT/US2024/028392 US2024028392W WO2024253796A1 WO 2024253796 A1 WO2024253796 A1 WO 2024253796A1 US 2024028392 W US2024028392 W US 2024028392W WO 2024253796 A1 WO2024253796 A1 WO 2024253796A1
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WIPO (PCT)
Prior art keywords
data
ran
time
synchronization
digital baseband
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PCT/US2024/028392
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English (en)
Inventor
Theodore E. Dahlen
Christopher Goodman Ranson
Stuart D. Sandberg
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Outdoor Wireless Networks LLC
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Outdoor Wireless Networks LLC
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Publication of WO2024253796A1 publication Critical patent/WO2024253796A1/fr
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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L49/00—Packet switching elements
    • H04L49/90—Buffering arrangements
    • H04L49/9023—Buffering arrangements for implementing a jitter-buffer
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L12/00—Data switching networks
    • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
    • H04L12/46—Interconnection of networks
    • H04L12/4633—Interconnection of networks using encapsulation techniques, e.g. tunneling
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L47/00—Traffic control in data switching networks
    • H04L47/10—Flow control; Congestion control
    • H04L47/28—Flow control; Congestion control in relation to timing considerations
    • H04L47/283—Flow control; Congestion control in relation to timing considerations in response to processing delays, e.g. caused by jitter or round trip time [RTT]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L47/00—Traffic control in data switching networks
    • H04L47/50—Queue scheduling
    • H04L47/62—Queue scheduling characterised by scheduling criteria
    • H04L47/6245—Modifications to standard FIFO or LIFO
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/08—Access point devices
    • H04W88/085—Access point devices with remote components

Definitions

  • a distributed antenna system typically includes one or more central units or nodes (also referred to here as “central access nodes (CANs)” or “master units”) that are communicatively coupled to a plurality of remotely located access points or antenna units (also referred to here as “remote units”), where each access point can be coupled directly to one or more of the central access nodes or indirectly via one or more other remote units and/or via one or more intermediary or expansion units or nodes (also referred to here as “transport expansion nodes (TENs)”).
  • a DAS is typically used to improve the coverage provided by one or more base stations that are coupled to the central access nodes. These base stations can be coupled to the one or more central access nodes via one or more cables or via a wireless connection, for example, using one or more donor antennas.
  • the wireless service provided by the base stations can include commercial cellular service and/or private or public safety wireless communications.
  • each central access node receives one or more downlink signals from one or more base stations and generates one or more downlink transport signals derived from one or more of the received downlink base station signals.
  • Each central access node transmits one or more downlink transport signals to one or more of the access points.
  • Each access point receives the downlink transport signals transmitted to it from one or more central access nodes and uses the received downlink transport signals to generate one or more downlink radio frequency signals that are radiated from one or more coverage antennas associated with that access point.
  • the downlink radio frequency signals are radiated for reception by user equipment (UEs).
  • UEs user equipment
  • the downlink radio frequency signals associated with each base station are simulcasted from multiple remote units. In this way, the DAS increases the coverage area for the downlink capacity provided by the base stations.
  • each access point receives one or more uplink radio frequency signals transmitted from the user equipment.
  • Each access point generates one or more uplink transport signals derived from the one or more uplink radio frequency signals and transmits them to one or more of the central access nodes.
  • Each central access node receives the respective uplink transport signals transmitted to it from one or more access points and uses the received uplink transport signals to generate one or more uplink base station radio frequency signals that are provided to the one or more base stations associated with that central access node.
  • this involves, among other things, summing uplink signals received from all of the multiple access points in order to produce the base station signal provided to each base station. In this way, the DAS increases the coverage area for the uplink capacity provided by the base stations.
  • a DAS can use either digital transport, analog transport, or combinations of digital and analog transport for generating and communicating the transport signals between the central access nodes, the access points, and any transport expansion nodes.
  • a donor base station is communicatively coupled to a DAS using an analog radio frequency (RF) interface or digital time-domain baseband interface.
  • RF radio frequency
  • a method for tunneling data in a distributed antenna system comprises: receiving at least one of: open radio access network (O-RAN) data and management data, wherein the O-RAN consists of O-RAN user data and O-RAN control data; buffering the at least one of: O-RAN data and management data; transmitting, in a first-in first-out manner, portions of buffered at least one of: O-RAN data and management data, wherein each portion of the buffered at least one of: O-RAN data and management data comprises data no larger than a first fixed data size; receiving time-domain digital baseband in-phase and quadrature phase (IQ) data; buffering the time-domain digital baseband IQ data; transmitting portions of buffered time-domain digital baseband IQ data, wherein each portion of the buffered time-domain digital baseband IQ data comprises data no larger than a second fixed data size; using the portions of time-domain digital baseband IQ data and the portions of buffered at least one of: O-
  • O-RAN open radio access network
  • a method for tunneling data in a distributed antenna system comprises: receiving an Ethernet frame including a streaming frame, wherein the streaming frame comprises at least one subframe of time-domain digital baseband in-phase and quadrature phase (IQ) data and at least one subframe of O-RAN data and/or management data wherein the O-RAN consists of O-RAN user data and O-RAN control data; extracting a streaming frame of service data from each subframe of the service data the Ethernet frame of service data; storing the time-domain digital baseband IQ data from each subframe; periodically transmitting no more than a fixed amount of time-domain digital baseband IQ data; buffering the O-RAN data and/or management data; using buffered O- RAN data and/or management data, forming at least one of: a message of O-RAN data and a message of management data; transmitting the at least one of: an O-RAN message and a message about management data; receiving an Ethernet frame of synchronization data; extracting a first synchronization
  • a method for streaming, in a fronthaul network of a distributed antenna system (DAS), time-domain digital baseband in-phase and quadrature phase (IQ) data and optionally streaming data comprises: receiving a subset of data, of a block of data, wherein the subset of data includes an amount of data equal to an amount of data which can be transmitted in a payload of a streaming frame; forming the streaming frame including the payload using data of the subset, received on a first in first out basis, by time division multiplexing together subframes of such data, wherein an amount of the data in the payload of the streaming frame is less than the amount of data in the block of data; upon forming the streaming frame, transmitting, in a downlink path of the fronthaul network of the DAS, the streaming frame including the payload; receiving synchronization data; and transmitting, in the downlink path of the fronthaul network of the DAS, the synchronization data or other synchronization data formed using the received synchronization data.
  • DAS distributed antenna system
  • FIG. 1 illustrates a block diagram of an exemplary embodiment of a distributed antenna system that is configured to serve one or more base stations;
  • FIG. 2 is a block diagram illustrating one exemplary embodiment of an RF donor that can be used in the DAS of FIG. 1 ;
  • FIG. 3 illustrates a block diagram of one embodiment of an intermediate combining node configured to transport service data and synchronization data
  • FIG. 4 illustrates one embodiment of an exemplary block diagram of transport interface circuitry
  • FIG. 5 illustrates a block diagram of one embodiment of an exemplary streaming frame of service data and time-domain digital baseband IQ data
  • FIG. 6 illustrates a flow diagram of one embodiment of a method of generating an Ethernet frame with interleaved subframes of time-domain digital baseband IQ data and of O-RAN data and/or management data;
  • FIG. 7 illustrates a flow diagram of one embodiment of a method of extracting (a) time-domain digital baseband IQ data and O-RAN data and/or management data, and (b) synchronization data respectively from an Ethernet frame of service data and an Ethernet frame of synchronization data; and
  • FIG. 8 illustrates a flow diagram of one embodiment of a method 880 for streaming, in a fronthaul network of a DAS, time-domain digital baseband IQ data and optionally service data.
  • Embodiments of inventions pertain to a DAS configured to transmit and receive both
  • time-domain digital baseband data 1 respectively to and from RF-interface base station(s) and/or baseband unit(s) (e.g., common public radio interface (CPRI) baseband unit(s)) and
  • baseband unit(s) e.g., common public radio interface (CPRI) baseband unit(s)
  • the other source(s) may also include alternative source(s) configured to transmit and receive digital baseband data, e.g., frequency-domain digital baseband data, and which are not an RF-interface base station or a baseband unit.
  • Time-domain digital baseband data is subject to a strict latency requirement in a DAS fronthaul network.
  • Transport, in the DAS fronthaul network, of data transmitted to and received from other source(s) can cause latency of time-domain digital baseband data to exceed the latency requirement.
  • a latency requirement of the DAS fronthaul network may be exceeded due to additional transport of data transmitted to and received from other source(s).
  • the time-domain digital data is transported, for example, to and from an RF-interface base station or a baseband unit.
  • the time-domain digital baseband data is time-domain digital baseband in-phase and quadrature-phase (IQ) data.
  • the other source(s) include, e.g., management system(s) and/or Open Radio Access Network (O- RAN) distributed unit(s) (O-DU(s)).
  • the data transmitted to and received from the other source(s) may include management data transmitted to and/or received from the management system(s) and/or O-RAN data transmitted to and/or received from the O-DU.
  • O-RAN data includes O-RAN user-, control-, and management- plane data (or messages).
  • O-RAN userplane data includes frequency-domain digital baseband data, e.g., frequency-domain digital baseband in-phase and quadrature phase (IQ) data.
  • IQ quadrature phase
  • the data transmitted to and received from other source(s) is communicated in a streaming frame.
  • the streaming frame comprises interleaved subframe(s) of time-domain digital baseband data and subframe(s) of the data transmitted to and received from other source(s), and a header.
  • Such interleaved subframe(s) are formed using time-division multiplexing (TDM).
  • TDM time-division multiplexing
  • the streaming frame may also be referred to as a TDM streaming frame.
  • data transmitted to and from other source(s) may be referred to hereinafter as application layer data that is not synchronization data (ALDNS).
  • Application layer data means data communicated at application layer 7 of the Open System Interconnection (OSI) model.
  • Application layer data includes synchronization data, management data, and other data, e.g., O-RAN data.
  • bandwidth of ALDNS and time-domain digital baseband data may be controlled based on an allocation of (a) a number of subframe(s) of ALDNS in a streaming frame and (b) a number of subframe(s) of time-domain digital data in the streaming frame.
  • latency, of time-domain digital baseband data communicated in the DAS fronthaul network may be constrained to be less than or equal to the latency requirement.
  • Service data means time-domain digital baseband data and ALDNS (or optionally time-domain digital baseband data and O-RAN data and/or management data) each of which comprises one or more subframes of the streaming frame.
  • Embodiments of the invention utilizing the aforementioned streaming frames may be used for purposes other than satisfying a latency requirement.
  • it may be easier to implement a DAS fronthaul network using tunneling for such transport of data to and from another source that is not an RF-interface base station or a baseband unit.
  • O-RAN data means O-RAN user plane data and O-RAN control plane data and/or management plane data.
  • Management data means O-RAN management plane data and/or management plane data from a management system.
  • Synchronization data includes O-RAN synchronization data. Some of the management data may be communicated to and from a management system.
  • Embodiments of the invention may be implemented a DAS fronthaul network that is an asynchronous network, a synchronous network, or combinations thereof. Use of a synchronous DAS fronthaul network reduces latency of the network by avoiding store and forward functionality of Ethernet switches.
  • a network (or a link) between two components of the DAS fronthaul network may be synchronous or asynchronous.
  • a network between the two components of the DAS fronthaul network is an Ethernet network, e.g., a point-to-point Ethernet network (an asynchronous network) or a switched Ethernet network (a synchronous network).
  • Ethernet network(s) When embodiments of the invention are implemented with Ethernet network(s), commercial off the shelf Ethernet equipment can be used in part to form the DAS fronthaul network. As a result, DAS fronthaul network installation cost is reduced. For pedagogical purposes, embodiments of the invention will be subsequently described as using Ethernet network(s).
  • Synchronization data (or timing data) is provided by a master timing entity to the DAS fronthaul network.
  • Synchronization data means data conveying timing information.
  • the synchronization data may be in a form of a precision time protocol (PTP) or network time protocol (NTP) packet Ethernet frames or messages.
  • PTP precision time protocol
  • NTP network time protocol
  • Such synchronization data is configured to be communicated separately from the service data, e.g., including streaming frames of service data.
  • DASs will now be described. However, DASs may be implemented in other configurations.
  • FIG. 1 illustrates a block diagram of an exemplary embodiment of a distributed antenna system (DAS) 100 that is configured to serve one or more base stations 102.
  • the DAS 100 includes one or more donor units 104 that are used to couple the DAS 100 to the base stations 102.
  • the DAS 100 also includes a plurality of remotely located radio units (RUs) 106 (also referred to as “antenna units,” “access points,” “remote units,” or “remote antenna units”).
  • the RUs 106 are communicatively coupled to the donor units 104.
  • Donor unit may also be referred to herein as a donor circuit, a donor card, or a donor interface.
  • a CPRI donor unit 118, an O-RAN donor unit 122, and a master unit 130 are coupled to the RUs 106 and ICNs 112 via one or more RF donors 114 or another ICN 112.
  • the RF donor 114 or the other ICN 112 performs transport frame multiplexing and demultiplexing described elsewhere herein.
  • Each RU 106 includes, or is otherwise associated with, a respective set of coverage antennas 108 via which downlink analog RF signals can be radiated to user equipment (UEs) 110 and via which uplink analog RF signals transmitted by UEs 110 can be received.
  • the DAS 100 is configured to serve each base station 102 using a respective subset of RUs 106 (which may include less than all of the RUs 106 of the DAS 100). Also, the subsets of RUs 106 used to serve the base stations 102 may differ from base station 102 to base station 102.
  • the subset of RUs points 106 used to serve a given base station 102 is also referred to here as the “simulcast zone” for that base station 102.
  • the wireless coverage of a base station 102 served by the DAS 100 is improved by radiating a set of downlink RF signals for that base station 102 from the coverage antennas 108 associated with the multiple RUs 106 in that base station’s stations simulcast zone and by producing a single “combined” set of uplink base station signals or data that is provided to that base station 102.
  • the single combined set of uplink base station signals or data is produced by a combining or summing process that uses inputs derived from the uplink RF signals received via the coverage antennas 108 associated with the RUs 106 in that base station’s simulcast zone.
  • the DAS 100 can also include one or more intermediary combining nodes (ICNs) 112 (also referred to as “expansion” units or nodes).
  • ICNs intermediary combining nodes
  • the ICN 112 For each base station 102 served by a given ICN 112, the ICN 112 is configured to receive a set of uplink transport data for that base station 102 from a group of “southbound” entities (that is, from RUs 106 and/or other ICNs 112) and generate a single set of combined uplink transport data for that base station 102, which the ICN 112 transmits “northbound” towards the donor unit 104 serving that base station 102.
  • group of “southbound” entities that is, from RUs 106 and/or other ICNs 112
  • the single set of combined uplink transport data for each served base station 102 is produced by a combining or summing process that uses inputs derived from the uplink RF signals received via the coverage antennas 108 of any southbound RUs 106 included in that base station’s simulcast zone.
  • southbound refers to traveling in a direction “away,” or being relatively “farther,” from the donor units 104 and base stations 102
  • nothbound refers to traveling in a direction “towards”, or being relatively “closer” to, the donor units 104 and base stations 102.
  • each ICN 112 also forwards downlink transport data to the group of southbound RUs 106 and/or ICNs 112 served by that ICN 112.
  • ICNs 112 can be used to increase the number of RUs 106 that can be served by the donor units 104 while reducing the processing and bandwidth load relative to having the additional RUs 106 communicate directly with each such donor unit 104.
  • one or more RUs 106 can be configured in a “daisy-chain” or “ring” configuration in which transport data for at least some of those RUs 106 is communicated via at least one other RU 106.
  • Each RU 106 would also perform the combining or summing process for any base station 102 that is served by that RU 106 and one or more of the southbound entities subtended from that RU 106. (Such a RU 106 also forwards northbound all other uplink transport data received from its southbound entities.)
  • the DAS 100 can include various types of donor units 104.
  • a donor unit 104 is an RF donor unit 114 that is configured to couple the DAS 100 to a base station 116 using the external analog radio frequency (RF) interface of the base station 116 that would otherwise be used to couple the base station 116 to one or more antennas (if the DAS 100 were not being used).
  • This type of base station 116 is also referred to here as an “RF- interface” base station 116.
  • An RF-interface base station 116 can be coupled to a corresponding RF donor unit 114 by coupling each antenna port of the base station 116 to a corresponding port of the RF donor unit 114.
  • Each RF donor unit 114 serves as an interface between each served RF-interface base station 116 and the rest of the DAS 100 and receives downlink base station signals from, and outputs uplink base station signals to, each served RF-interface base station 116.
  • Each RF donor unit 114 performs at least some of the conversion processing necessary to convert the base station signals to and from the digital fronthaul interface format natively used in the DAS 100 for communicating time-domain baseband data.
  • the downlink and uplink base station signals communicated between the RF-interface base station 116 and the donor unit 114 are analog RF signals.
  • the digital fronthaul interface format natively used in the DAS 100 for communicating time-domain baseband data can comprise the O-RAN fronthaul interface, a CPRI or enhanced CPRI (eCPRI) digital fronthaul interface format, or a proprietary digital fronthaul interface format (though other digital fronthaul interface formats can also be used).
  • a donor unit 104 is a digital donor unit that is configured to communicatively couple the DAS 100 to a baseband entity using a digital baseband fronthaul interface that would otherwise be used to couple the baseband entity to a radio unit (if the DAS 100 were not being used). In the example shown in FIG. 1, two types of digital door units are shown.
  • the first type of digital donor unit comprises a digital donor unit 118 that is configured to communicatively couple the DAS 100 to a baseband unit (BBU) 120 using a time-domain baseband fronthaul interface implemented in accordance with a Common Public Radio Interface (“CPRI”) specification.
  • This type of digital donor unit 118 is also referred to here as a “CPRI” donor unit 118, and this type of BBU 120 is also referred to here as a CPRI BBU 120.
  • the CPRI donor unit 118 For each CPRI BBU 120 served by a CPRI donor unit 118, the CPRI donor unit 118 is coupled to the CPRI BBU 120 using the CPRI digital baseband fronthaul interface that would otherwise be used to couple the CPRI BBU 120 to a CPRI remote radio head (RRH) (if the DAS 100 were not being used).
  • RRH CPRI remote radio head
  • a CPRI BBU 120 can be coupled to a corresponding CPRI donor unit 118 via a direct CPRI connection.
  • Each CPRI donor unit 118 serves as an interface between each served CPRI BBU 120 and the rest of the DAS 100 and receives downlink base station signals from, and outputs uplink base station signals to, each CPRI BBU 120.
  • Each CPRI donor unit 118 performs at least some of the conversion processing necessary to convert the CPRI base station data to and from the digital fronthaul interface format natively used in the DAS 100 for communicating time-domain baseband data.
  • the downlink and uplink base station signals communicated between each CPRI BBU 120 and the CPRI donor unit 118 comprise downlink and uplink fronthaul data generated and formatted in accordance with the CPRI baseband fronthaul interface.
  • the second type of digital donor unit comprises a digital donor unit 122 that is configured to communicatively couple the DAS 100 to a BBU 124 using a frequency-domain baseband fronthaul interface implemented in accordance with a O-RAN Alliance specification.
  • the acronym “O-RAN” is an abbreviation for “Open Radio Access Network.”
  • This type of digital donor unit 122 is also referred to here as an “O-RAN” donor unit 122
  • this type of BBU 124 is typically an O-RAN distributed unit (DU) and is also referred to here as an O-RAN DU 124.
  • DU O-RAN distributed unit
  • the O-RAN donor unit 122 is coupled to the O-DU 124 using the O-RAN digital baseband fronthaul interface that would otherwise be used to couple the O-RAN DU 124 to a O-RAN RU (if the DAS 100 were not being used).
  • An O-RAN DU 124 can be coupled to a corresponding O- RAN donor unit 122 via a switched Ethernet network.
  • an O-RAN DU 124 can be coupled to a corresponding O-RAN donor unit 122 via a direct Ethernet or CPRI connection.
  • Each O-RAN donor unit 122 serves as an interface between each served O-RAN DU 124 and the rest of the DAS 100 and receives downlink base station signals from, and outputs uplink base station signals to, each O-RAN DU 124.
  • Each O-RAN donor unit 122 performs at least some of any conversion processing necessary to convert the base station signals to and from the digital fronthaul interface format natively used in the DAS 100 for communicating frequency-domain baseband data.
  • the downlink and uplink base station signals communicated between each O-RAN DU 124 and the O-RAN donor unit 122 comprise downlink and uplink fronthaul data generated and formatted in accordance with the O-RAN baseband fronthaul interface, where the user-plane data comprises frequencydomain baseband IQ data.
  • such downlink and uplink fronthaul data is communicated directly between the O-RAN donor unit 122 and the RF donor unit 114, or between the O-RAN donor unit 122 and the RF donor unit 114 through an optional master unit 130 (as illustrated in FIG. 1); for pedagogical purposes, the optional master unit 130 shall be described, for pedagogical purposes, as part of the DAS 100.
  • the digital fronthaul interface format natively used in the DAS 100 for communicating O-RAN fronthaul data is the same O-RAN fronthaul interface used for communicating base station signals between each O-RAN DU 124 and the O-RAN donor unit 122, and the “conversion” performed by each O-RAN donor unit 122 (and/or one or more other entities of the DAS 100) includes performing any needed “multicasting” of the downlink data received from each O-RAN DU 124 to the multiple RUs 106 in a simulcast zone for that O-RAN DU 124 (for example, by communicating the downlink fronthaul data to an appropriate multicast address and/or by copying the downlink fronthaul data for communication over different fronthaul links) and performing any need combining or summing of the uplink data received from the RUs 106 to produce combined uplink data provided to the O-RAN DU 124. It is to be understood that other digital fronthaul interface formats can also be used.
  • the various base stations 102 are configured to communicate with a core network (not shown) of the associated wireless operator using an appropriate backhaul network (typically, a public wide area network such as the Internet). Also, the various base stations 102 may be from multiple, different wireless operators and/or the various base stations 102 may support multiple, different wireless protocols and/or RF bands.
  • the DAS fronthaul network 139 includes one or more donors units 104, one or more ICN(s) 112, and one or more RUs 106, and optionally a master unit 130.
  • the DAS 100 is configured to receive a set of one or more downlink base station signals from the base station 102 (via an appropriate donor unit 104), generate downlink transport data derived from the set of downlink base station signals, and transmit the downlink transport data to the RUs 106 in the base station’s simulcast zone.
  • the RU 106 is configured to receive the downlink transport data transmitted to it via the DAS 100 and use the received downlink transport data to generate one or more downlink analog radio frequency signals that are radiated from one or more coverage antennas 108 associated with that RU 106 for reception by user equipment 110.
  • the DAS 100 increases the coverage area for the downlink capacity provided by the base stations 102.
  • the RU 106 forwards any downlink transport data intended for those southbound entities towards them.
  • the RU 106 For each base station 102 served by a given RU 106, the RU 106 is configured to receive one or more uplink radio frequency signals transmitted from the user equipment 110. These signals are analog radio frequency signals and are received via the coverage antennas 108 associated with that RU 106. The RU 106 is configured to generate uplink transport data derived from the one or more remote uplink radio frequency signals received for the served base station 102 and transmit the uplink transport data northbound towards the donor unit 104 coupled to that base station 102.
  • a single “combined” set of uplink base station signals or data is produced by a combining or summing process that uses inputs derived from the uplink RF signals received via the RUs 106 in that base station’s simulcast zone.
  • the resulting final single combined set of uplink base station signals or data is provided to the base station 102.
  • This combining or summing process can be performed in a centralized manner in which the combining or summing process is performed by a single unit of the DAS 100 (for example, a donor unit 104 or master unit 130).
  • This combining or summing process can also be performed in a distributed or hierarchical manner in which the combining or summing process is performed by multiple units of the DAS 100 (for example, a donor unit 104 (or master unit 130) and one or more ICNs 112 and/or RUs 106).
  • Each unit of the DAS 100 that performs the combining or summing process for a given base station 102 receives uplink transport data from that unit’s southbound entities and uses that data to generate combined uplink transport data, which the unit transmits northbound towards the base station 102.
  • the generation of the combined uplink transport data involves, among other things, extracting in-phase and quadraturephase (IQ) data from the received uplink transport data and performing a combining or summing process using any uplink IQ data for that base station 102 in order to produce combined uplink IQ data.
  • IQ in-phase and quadraturephase
  • the associated RF donor unit 114 receives analog downlink RF signals from the RF-interface base station 116 and, either alone or in combination with one or more other units of the DAS 100, converts the received analog downlink RF signals to the digital fronthaul interface format natively used in the DAS 100 for communicating time-domain baseband data (for example, by digitizing, digitally down-converting, and filtering the received analog downlink RF signals in order to produce digital baseband IQ data and formatting the resulting digital baseband IQ data into packets) and communicates the resulting packets of downlink transport data to the various RUs 106 in the simulcast zone of that base station 116.
  • the RUs 106 in the simulcast zone for that base station 116 receive the downlink transport data and use it to generate and radiate downlink RF signals as described above.
  • the RF donor unit 114 In the uplink, either alone or in combination with one or more other units of the DAS 100, the RF donor unit 114 generates a set of uplink base station signals from uplink transport data received by the RF donor unit 114 (and/or the other units of the DAS 100 involved in this process).
  • the set of uplink base station signals is provided to the served base station 116.
  • the uplink transport data is derived from the uplink RF signals received at the RUs 106 in the simulcast zone of the served base station 116 and communicated in packets.
  • the associated CPRI digital donor unit 118 receives CPRI downlink fronthaul data from the CPRI BBU 120 and, either alone or in combination with another unit of the DAS 100, converts the received CPRI downlink fronthaul data to the digital fronthaul interface format natively used in the DAS 100 for communicating time- domain baseband data (for example, by re-sampling, synchronizing, combining, separating, gain adjusting, etc. the CPRI baseband IQ data, and formatting the resulting baseband IQ data into packets), and communicates the resulting packets of downlink transport data to the various RUs 106 in the simulcast zone of that CPRI BBU 120.
  • the RUs 106 in the simulcast zone of that CPRI BBU 120 receive the packets of downlink transport data and use them to generate and radiate downlink RF signals as described above.
  • the CPRI donor unit 118 In the uplink, either alone or in combination with one or more other units of the DAS 100, the CPRI donor unit 118 generates uplink base station data from uplink transport data received by the CPRI donor unit 118 (and/or the other units of the DAS 100 involved in this process). The resulting uplink base station data is provided to that CPRI BBU 120.
  • the uplink transport data is derived from the uplink RF signals received at the RUs 106 in the simulcast zone of the CPRI BBU 120.
  • the associated O-RAN donor unit 122 receives packets of O-RAN downlink fronthaul data (that is, O-RAN user-plane and control-plane messages) from each O-RAN DU 124 coupled to that O-RAN digital donor unit 122 and, either alone or in combination with another unit of the DAS 100, converts (if necessary) the received packets of O-RAN downlink fronthaul data to the digital fronthaul interface format natively used in the DAS 100 for communicating O-RAN baseband data and communicates the resulting packets of downlink transport data to the various RUs 106 in a simulcast zone for that ORAN DU 124.
  • O-RAN downlink fronthaul data that is, O-RAN user-plane and control-plane messages
  • the RUs 106 in the simulcast zone of each O-RAN DU 124 receive the packets of downlink transport data and use them to generate and radiate downlink RF signals as described above.
  • the O-RAN donor unit 122 In the uplink, either alone or in combination with one or more other units of the DAS 100, the O-RAN donor unit 122 generates packets of uplink base station data from uplink transport data received by the O-RAN donor unit 122 (and/or the other units of the DAS 100 involved in this process). The resulting packets of uplink base station data are provided to the O-RAN DU 124.
  • the uplink transport data is derived from the uplink RF signals received at the RUs 106 in the simulcast zone of the served O-RAN DU 124 and communicated in packets.
  • one of the units of the DAS 100 is also used to implement a “master” timing entity for the DAS 100 (for example, such a master timing entity can be implemented as a part of a master unit 130 described below); alternatively, the master timing entity may be implemented by another system communicatively coupled to the DAS 100. In another example, a separate, dedicated timing master entity (not shown) is provided within the DAS 100. In either case, the master timing entity synchronizes itself to an external timing master entity (for example, a timing master associated with one or more of the O-DUs 124) and, in turn, that entity serves as a timing master entity for the other units of the DAS 100.
  • an external timing master entity for example, a timing master associated with one or more of the O-DUs 12
  • a time synchronization protocol for example, the Institute of Electrical and Electronics Engineers (IEEE) 1588 Precision Time Protocol (PTP), the Network Time Protocol (NTP), or the Synchronous Ethernet (SyncE) protocol
  • PTP Precision Time Protocol
  • NTP Network Time Protocol
  • Synchronous Ethernet (SyncE) protocol can be used to implement such time synchronization.
  • the master timing entity is configured to provide the synchronization data described elsewhere herein.
  • Synchronization data (not in an Ethernet frame) may be referred to herein as synchronization message(s).
  • a management system (not shown) can be used to manage the various nodes of the DAS 100.
  • the management system communicates with a predetermined “master” entity for the DAS 100 (for example, the master unit 130 described below), which in turns forwards or otherwise communicates with the other units of the DAS 100 for management-plane purposes.
  • the management system communicates with the various units of the DAS 100 directly for management-plane purposes (that is, without using a master entity as a gateway).
  • Each base station 102 (including each RF-interface base station 116, CPRI BBU 120, and O-RAN DU 124), donor unit 104 (including each RF donor unit 114, CPRI donor unit 118, and O-RAN donor unit 122), RU 106, ICN 112, and any of the specific features described here as being implemented thereby, can be implemented in hardware, software, or combinations of hardware and software, and the various implementations (whether hardware, software, or combinations of hardware and software) can also be referred to generally as “circuitry,” a “circuit,” or “circuits” that is or are configured to implement at least some of the associated functionality.
  • such software can be implemented in software or firmware executing on one or more suitable programmable processors (or other programmable device) or configuring a programmable device (for example, processors or devices included in or used to implement special-purpose hardware, general-purpose hardware, and/or a virtual platform).
  • suitable programmable processors or other programmable device
  • configuring a programmable device for example, processors or devices included in or used to implement special-purpose hardware, general-purpose hardware, and/or a virtual platform.
  • the software can comprise program instructions that are stored (or otherwise embodied) on or in an appropriate non-transitory storage medium or media (such as flash or other non-volatile memory, magnetic disc drives, and/or optical disc drives) from which at least a portion of the program instructions are read by the programmable processor or device for execution thereby (and/or for otherwise configuring such processor or device) in order for the processor or device to perform one or more functions described here as being implemented the software.
  • an appropriate non-transitory storage medium or media such as flash or other non-volatile memory, magnetic disc drives, and/or optical disc drives
  • Such hardware or software (or portions thereof) can be implemented in other ways (for example, in an application specific integrated circuit (ASIC), etc.).
  • ASIC application specific integrated circuit
  • the DAS 100 can be implemented in a virtualized manner or a non-virtualized manner.
  • one or more nodes, units, or functions of the DAS 100 are implemented using one or more virtual network functions (VNFs) executing on one or more physical server computers (also referred to here as “physical servers” or just “servers”) (for example, one or more commercial-off-the-shelf (COTS) servers of the type that are deployed in data centers or “clouds” maintained by enterprises, communication service providers, or cloud services providers).
  • VNFs virtual network functions
  • COTS commercial-off-the-shelf
  • the server 126 can execute other VNFs 128 that implement other functions for the DAS 100 (for example, fronthaul, management plane, and synchronization plane functions).
  • the various VNFs executing on the server 126 are also referred to here as “master unit” functions 130 or, collectively, as the “master unit” 130.
  • each ICN 112 is implemented as a VNF running on a server 126.
  • the O-RAN donor 122 is communicatively coupled to an O-RAN DU 124.
  • An O- RAN donor 122 may be communicatively coupled to the RF donor 114 (e.g., through a first Ethernet network 137a) or to an ICN 112 (e.g., the ICN 112 communicatively coupled to the RF donor 114 (without any interceding ICNs 112)).
  • the O-RAN donor 122 may be communicatively coupled to the ICN 112 through a second Ethernet network 137b.
  • Fig. 1 illustrates that the O-RAN donor 122 is communicatively coupled to both the RF donor 114 and the ICN 112, this is for pedagogical purposes only and the O-RAN donor 122 would be communicatively coupled to only one of the RF donor 114 and the ICN 112.
  • a first O-RAN donor may be communicatively coupled to the RF donor 114 and a second O-RAN donor may be communicatively coupled to the ICN 112.
  • Each of the Ethernet networks 136, 137a, 137b of FIG. 1 may be implemented by a point-to-point Ethernet network or a switched Ethernet network.
  • An O-RAN donor 122 may be communicatively coupled to the RF donor 114 or the ICN 112 by a switched or a point-to-point Ethernet network.
  • the first Ethernet network 137a also communicatively couples the master unit 130 to the RF donor 114.
  • the second Ethernet network 137b also communicatively couples the master unit 130 to the ICN 112.
  • Each of the first and the second Ethernet networks 137a, 137b are configured to convey service data and synchronization data between the two components which they communicatively couple.
  • the master unit 130 communicatively couples the O-RAN DU 124 with the RF donor 114 or the ICN 112.
  • the master unit 130 includes the O-RAN donor 122.
  • an O-RAN donor 122 may be communicatively coupled to the RF donor 114 or the ICN 112 without the master unit 130 being communicatively coupled between the O- RAN donor 122 and the RF donor 114.
  • the RF donor units 114 and CPRI donor units 118 can be implemented as cards (for example, Peripheral Component Interconnect (PCI) Cards) that are inserted in the server 126.
  • the RF donor units 114 and CPRI donor units 118 can be implemented as separate devices that are each coupled to the server 126 via a dedicated point-to-point or switched Ethernet network.
  • the CPRI donor units 118, O-RAN donor unit 122, and master unit 130 are coupled to the RUs 106 and zero or more ICNs 112 via one or more RF donors 114 and/or one or more ICNs 112. Each RF donor 114 performs multiplexing and demultiplexing of frames.
  • the donor units 104, RUs 106 and ICNs 112 are communicatively coupled to one another via Ethernet networks.
  • an O- RAN DU 124 can be coupled to a corresponding O-RAN donor unit 122 via a switched Ethernet network (not shown in FIG. 1), though that switched Ethernet network is not used for communication within the DAS 100.
  • the downlink and uplink transport data communicated between the units of the DAS 100 is communicated in Ethernet packets over the Ethernet links 136.
  • each southbound Ethernet link 136 that couples a source RF donor 114 (communicatively coupled to an O-RAN donor 122) or a source ICN 112 (communicatively coupled to the O-RAN donor 122) to another ICN 112, the respective source RF donor 114 or the source ICN 112 assembles downlink transport or streaming frames and communicates them in downlink Ethernet packets to the other ICN 112 over the Ethernet link 136.
  • each downlink streaming frame time division multiplexes together subframes of downlink time-domain baseband IQ data and service data that needs to be communicated to southbound RUs 106 and other ICNs 112 that are coupled respectively to the source RF donor 114 or the source ICN 112 via that Ethernet link 136.
  • the downlink time-domain baseband IQ data is sourced from one or more RF donor units 114 and/or CPRI donor units 118. That is, this service data is encapsulated into downlink frames of interleaved subframes of service data.
  • a streaming frame of service data, in an Ethernet frame is also referred to here as “encapsulated” Ethernet data or Ethernet data.
  • the resulting downlink streaming frames of interleaved service data are communicated in the payload of downlink Ethernet packets or frames communicated from respectively the source RF donor 114 or the source ICN 112 to the other ICN 112 over the Ethernet link 136.
  • the Ethernet packets including the encapsulated Ethernet data are also referred to here as “transport” Ethernet packets.
  • Each ICN 112 receives downlink transport Ethernet packets via each northbound Ethernet link 136 and extracts any downlink time-domain baseband IQ data and/or encapsulated ALDNS included in the downlink transport frames communicated via the received downlink transport Ethernet packets. Any encapsulated Ethernet data that is intended for the ICN 112 (for example, management-plane Ethernet data) is processed by the ICN 112.
  • the ICN 112 For each southbound Ethernet link 136 coupled to the ICN 112, the ICN 112 assembles downlink transport frames and communicates them in downlink Ethernet packets to the southbound entities subtended from the ICN 112 via the Ethernet link 136.
  • each downlink transport frame For each southbound Ethernet link 136, each downlink transport frame time division multiplexes together downlink time-domain baseband IQ data and ALDNS received at the ICN 112 that needs to be communicated to those subtended southbound entities.
  • the resulting downlink transport frames are communicated in the payload of downlink transport Ethernet packets communicated from the ICN 112 to those subtended southbound entities ICN 112 over the Ethernet link 136.
  • Each RU 106 receives downlink transport Ethernet packets via each northbound Ethernet link 136 and extracts any downlink time-domain baseband IQ data and/or encapsulated Ethernet data included in the downlink transport frames communicated via the received downlink transport Ethernet packets. As described above, the RU 106 uses any downlink time-domain baseband IQ data and/or downlink O-RAN user-plane and controlplane fronthaul messages to generate downlink RF signals for radiation from the set of coverage antennas 108 associated with that RU 106. The RU 106 processes any management-plane messages communicated to that RU 106 via encapsulated Ethernet data.
  • the RU 106 For any southbound Ethernet link 136 coupled to the RU 106, the RU 106 assembles downlink transport frames and communicates them in downlink Ethernet packets to the southbound entities subtended from the RU 106 via the Ethernet link 136. For each southbound Ethernet link 136, each downlink transport frame multiplexes together downlink time-domain baseband IQ data and ALDNS received at the RU 106 that needs to be communicated to those subtended southbound entities. The resulting downlink transport frames are communicated in the payload of downlink transport Ethernet packets communicated from the RU 106 to those subtended southbound entities ICN 112 over the Ethernet link 136.
  • each RU 106 In the uplink, each RU 106 generates uplink time-domain baseband IQ data and/or uplink O-RAN user-plane fronthaul messages for each RF-interface base station 116, CPRI BBU 120, and/or O-RAN DU 124 served by that RU 106 as described above. For each northbound Ethernet link 136 of the RU 106, the RU 106 assembles uplink transport frames and communicates them in uplink transport Ethernet packets northbound towards a destination RF donor 114 and/or a destination ICN 112 via Ethernet link(s) 136.
  • each uplink transport frame multiplexes together uplink timedomain baseband IQ data originating from that RU 106 and/or any southbound entity subtended from that RU 106 as well as any Ethernet data originating from that RU 106 and/or any southbound entity subtended from that RU 106.
  • the RU 106 performs the combining or summing process described above for any base station 102 served by that RU 106 and also by one or more of the subtended entities.
  • the RU 106 forwards northbound all other uplink data received from those southbound entities.
  • the resulting uplink transport frames are communicated in the payload of uplink transport Ethernet packets northbound towards the designation RF donor 114 and/or the destination ICN 112 via the associated Ethernet link(s) 136.
  • a destination or source RF donor 114 means an RF donor 114 communicatively connected to an O-RAN donor through a first Ethernet network 137a.
  • a destination or source ICN 112 means an ICN 112 communicatively connected to an O-RAN donor through a second Ethernet network 137b.
  • Each ICN 112 receives uplink transport Ethernet packets via each southbound Ethernet link 136 and extracts any uplink time-domain baseband IQ data and/or encapsulated Ethernet data included in the uplink transport frames communicated via the received uplink transport Ethernet packets. For each northbound Ethernet link 136 coupled to the ICN 112, the ICN 112 assembles uplink transport frames and communicates them in uplink transport Ethernet packets northbound towards the destination RF donor 114 and/or the destination ICN 112 via Ethernet link(s) 136, 137a, 137b.
  • each uplink transport frame For each northbound Ethernet link 136, each uplink transport frame multiplexes together uplink time-domain baseband IQ data and ALDNS received at the ICN 112 that needs to be communicated northbound towards the destination RF donor 114 and/or destination ICN 112.
  • the ICN 112 performs the combining or summing process described above for any base station 102 served by that ICN 112 for which it has received uplink baseband IQ data from multiple entities subtended from that ICN 112.
  • the resulting uplink transport frames are communicated in the payload of uplink transport Ethernet packets communicated northbound towards destination RF donor 114 or the destination O-RAN donor over the Ethernet link 136.
  • Each RF donor 114 receives uplink transport Ethernet packets via each southbound Ethernet link 136 and extracts any uplink time-domain baseband IQ data and/or encapsulated Ethernet data included in the uplink transport frames communicated via the received uplink transport Ethernet packets. Any extracted uplink time-domain baseband IQ data, as well as any uplink O-RAN messages communicated in encapsulated Ethernet, is used in producing a single “combined” set of uplink base station signals or data for the associated base station 102 as described above (which includes performing the combining or summing process). Any other encapsulated Ethernet data (for example, managementplane Ethernet data) is forwarded on towards the respective destination (for example, a management entity).
  • managementplane Ethernet data for example, managementplane Ethernet data
  • synchronization-plane messages are communicated using native Ethernet packets (that is, non-encapsulated Ethernet packets) that are interleaved between the transport Ethernet packets.
  • FIG. 2 is a block diagram illustrating one exemplary embodiment of an RF donor 214 that can be used in the DAS 100 of FIG. 1.
  • the RF donor 214 is configured to transmit and receive Ethernet frames of service data and Ethernet frames of synchronization data respectively to and from an ICN 112.
  • the RF donor 214 is further configured to transmit and receive an analog RF signal respectively to and from an RF-interface base station 116, optionally application layer data respectively to and from an O-RAN donor 122 (e.g., a master unit 130), and optionally time-domain digital baseband IQ data respectively to and from a CPRI donor 118.
  • O-RAN donor 122 e.g., a master unit 130
  • the RF donor 214 comprises RF donor function circuitry (RF donor function) 222, optional routing function circuitry (routing function) 226, and transport interface (l/F) circuitry (transport l/F) 224.
  • the optional routing function circuitry 226 is configured to be communicatively coupled between the RF donor function circuitry 222 and the transport l/F circuitry 224.
  • the O-RAN donor 122 e.g., the master unit 130
  • the RF donor 214 need not include the optional routing function circuitry 226.
  • the RF donor function circuitry 222 and the transport l/F circuitry 224 are configured to be communicatively coupled to one another without interceding routing function circuitry 226.
  • FIG. 1 and 2 and related text herein describe a CPRI donor 118 communicatively coupled through an RF donor 114 to an ICN 112
  • the CPRI donor 118 can in the alternative be optionally communicatively coupled to the ICN 112 (e.g., when the ICN 112 is optionally communicatively coupled to the O-RAN donor 122) which would include the transport interface functionality and the optional routing functionality described herein (e.g., with respect to FIG. 2).
  • the RF donor function circuitry 222 is configured to provide the RF donor functionality described herein (e.g., down convert, digitize, frame, and serialize a downlink RF signal and deserialize, deframe, convert, and up convert time-domain digital baseband IQ data).
  • the RF donor function circuitry 222 is also configured to transmit and receive an analog RF signal respectively to and from an RF-interface base station 116, and to transmit and receive time domain digital baseband IQ data respectively to the transport interface (l/F) circuitry 224 or the optional routing function circuitry 226.
  • the RF donor function circuitry 222 is configured to convert the analog RF signal transmitted from the RF-interface base station 116 to time-domain digital baseband IQ data transmitted to the transport l/F circuitry or the optional routing function circuitry, and vice versa.
  • the optional routing function circuitry 226 is optionally communicatively coupled to a CPRI donor 118.
  • the optional routing function circuitry 226 is configured to transmit and receive time-domain digital baseband data respectively to and from each of the RF donor function circuitry 222 and a CPRI donor.
  • the optional routing function circuitry 226 is further configured to sequentially transmit to the transport l/F circuitry 224 time-domain digital baseband IQ data, from the RF donor function circuitry 222 and/or the CPRI donor 118, destined for the same RU(s) and to be transmitted by such RU(s) during a same time period, e.g., a frame or a sub-frame.
  • the optional routing function circuitry 226 is also configured to receive time-domain baseband IQ data from the transport l/F circuitry 224 and to route such time-domain baseband IQ data to its intended destination, i.e., the RF-interface base station 116 (through the RF donor function 222) or optionally the CPRI BBU 120 (through the CPRI donor 118).
  • the transport l/F circuitry 224 is configured to transmit and receive ALDNS (e g., O- RAN user, control, and/or management plane data and management data) and synchronization data respectively to and from an O-RAN donor 122.
  • ALDNS e g., O- RAN user, control, and/or management plane data and management data
  • the transport l/F circuitry 224 is further configured to transmit or receive time-domain digital baseband IQ data respectively to or from either the RF donor function circuitry 222 (if no routing function circuitry 226 is used), the CPRI donor 118, and/or the routing function circuitry 226.
  • the transport l/F circuitry 224 is also configured to form streaming frames of service data and frames of synchronization data (e.g., in a manner described elsewhere herein) and transmit Ethernet frames of service data and Ethernet frames of synchronization data, e.g., to an ICN 112.
  • the transport l/F circuitry 224 is also configured to receive Ethernet frames of service data and Ethernet frames of synchronization data from the ICN 112.
  • the transport l/F circuitry 224 is further configured to extract (a) ALDNS (e.g., O-RAN user, control, and/or management plane data) and (b) time-domain digital baseband IQ data from the received Ethernet frames of service data and to extract synchronization data from the received Ethernet frames of synchronization data.
  • ALDNS e.g., O-RAN user, control, and/or management plane data
  • the transport l/F circuitry 224 is also configured to transmit the ALDNS to the optional routing function circuitry, and/or the O-RAN donor, e.g., the master unit 130.
  • the data rate of the service data in subframe(s) received and transmitted by the transport l/F circuitry 224 is the same as the data rate of time-domain digital baseband IQ data respectively transmitted and received by the RF donor 214, e.g., by the RF donor function circuitry 222.
  • the ICNs 112 subtended from the transport l/F circuitry 224 of the RF donor 214 do not include transport l/F(s).
  • each of the RF donor function circuitry 222, routing function circuitry 226, and transport l/F circuitry 224 may be implemented by software and/or firmware configured to be executed by one or more programmable devices implemented in various ways (for example, using programmable processors (such as microprocessors, coprocessors, and processor cores integrated into other programmable devices) and/or programmable logic (such as FPGAs and system-on-chip packages)). Where multiple programmable devices are used, all of the programmable devices do not need to be implemented in the same way.
  • FIG. 3 illustrates a block diagram of one embodiment of an intermediate combining node (ICN) 312 configured to transport service data and synchronization data.
  • the ICN 312 is communicatively coupled, e.g., by an Ethernet network, to an O-RAN donor 122.
  • ICN 312 of FIG. 3 is illustrated as being communicatively coupled to the O-RAN donor 122.
  • the ICN 312 is configured to transmit and receive Ethernet frames of service data and Ethernet frames of synchronization data respectively to and from other ICN(s) 112, RU(s) 106, and/or O-RAN DU(s) 124.
  • each northbound Ethernet frame of service data comprises blocks of time-domain digital baseband IQ data received by the RU(s) 106 during a same fixed time interval or Jiffy.
  • each southbound Ethernet frame of service data comprises blocks of time-domain digital baseband IQ data transmitted the by RF-interface base station(s) 116 and/or the CPRI BBU(s) 120 during a same fixed time interval or Jiffy.
  • the ICN 312 includes an optional first transport l/F circuitry 324a, second transport l/F circuitry 324b, third transport l/F circuitry 324c, and routing function circuitry 332.
  • FIG. 3 illustrates an ICN 312 including the first transport l/F circuitry 324b.
  • the ICN 312 may not include the first transport l/F circuitry 324a if port(s) of the routing function circuitry 332 are communicatively coupled to an RF donor 114 and/or a CPRI donor 118 (without an intervening first transport l/F circuitry 324a.
  • FIG. 3 illustrates an ICN 312 including the first transport l/F circuitry 324b.
  • the ICN 312 may not include the first transport l/F circuitry 324a if port(s) of the routing function circuitry 332 are communicatively coupled to an RF donor 114 and/or a CPRI donor 118 (without an intervening first transport l/F circuitry 324
  • FIG. 3 illustrates an ICN 312 including the second and the third transport l/F circuitry 324b, 324c; however, other embodiments of the invention may comprise additional transport l/F circuitry (e.g., a fourth transport l/F circuitry, etc.) communicatively coupled between the routing function circuitry 332 and other sets of RU(s) or other ICNs.
  • additional transport l/F circuitry e.g., a fourth transport l/F circuitry, etc.
  • the routing function circuitry 332 is configured to (a) route ALDNS (e.g., O-RAN user, control, and/or management plane data) between the O-RAN donor 122 and one or more transport IF circuitry, (b) time-domain digital baseband IQ data (originating from or sent to an RF donor or a CPRI donor) between the first transport l/F circuitry 324a and another transport l/F circuitry (e.g., the second or the third transport l/F circuitry 324b, 324c), and (c) synchronization data between the first transport l/F circuitry 324a or the O-RAN donor 122 and another transport l/F circuitry (e.g., the second or the third transport l/F circuitry 324b, 324c) or the O-RAN donor 122.
  • the ICN 312, e.g., the routing function circuitry 332 is communicatively coupled to an O-RAN donor 122 through an Ethernet link, e.g.,
  • Such routing ensures that service data is routed from a source (an RU or donor (e.g., an O-RAN, a CPRI, or an RF donor)) to respectively a donor or an RU which is intended to receive such service data.
  • a source an RU or donor (e.g., an O-RAN, a CPRI, or an RF donor)
  • Each of the second and the third transport l/F circuitry 324b, 324c are communicatively coupled, optionally through one or more other ICNs 112, to an RU to which such service data (from a donor) is intended to be delivered.
  • the first transport IF circuitry 324a is communicatively coupled, optionally through one or more other ICNs 112 and/or another donor, to one or more donors of the same or different types.
  • the first transport l/F circuitry 324a is configured to transmit and receive time-domain digital baseband IQ data and application layer data respectively to and from the routing function circuitry 332.
  • the first transport l/F circuitry 324a is further configured to transmit and receive Ethernet frames of service data and Ethernet frames of synchronization data respectively to and from another (e.g., a first) ICN 112 or a donor (e.g., the RF donor) 114 including transport l/F circuitry.
  • another e.g., a first
  • a donor e.g., the RF donor
  • the time-domain digital baseband IQ data in an Ethernet frame of service data are transmitted to or received from an RF donor 114 or a CPRI donor 118.
  • the second transport l/F circuitry 324b is configured to transmit and receive timedomain digital baseband IQ data and application layer data respectively to and from the routing function circuitry 332.
  • the second transport l/F circuitry 324b is further configured to transmit and receive Ethernet frames of service data and Ethernet frames of synchronization data respectively to and from (e.g., a first set of) RU(s) or another (e.g., a second) ICN.
  • the third transport l/F circuitry 324c is configured to transmit and receive timedomain digital baseband IQ data and application layer data respectively to and from the routing function circuitry 332.
  • the third transport l/F circuitry 324c is further configured to transmit and receive Ethernet frames of service data and Ethernet frames of synchronization data respectively to and from other (e.g., a second set of) RU(s) or yet another (e g., a third) ICN.
  • the data rate of blocks of the service data in an Ethernet frame of service data transmitted or received by the ICN 312 is the same as the data rate of time-domain digital baseband IQ data received by or transmitted by the ICN 312.
  • the ICN(s) 112 subtended from the second and third transport l/Fs 324b, 324c of ICN 312 do not include transport l/F(s).
  • FIG. 4 illustrates one embodiment of an exemplary block diagram of transport interface (l/F) circuitry 400.
  • the transport l/F circuitry 400 comprises physical (PHY) circuitry (or PHY) 442, media access controller (MAC) circuitry (or MAC) 444, a first synchronization circuit (first PTP) 441a, a second synchronization circuit (second PTP) 441b, streaming decoder circuitry (streaming decoder) 446, Ethernet detunneler circuitry (Ethernet detunneler) 443, at least one receive buffer circuitry (RX buffer(s)) 449a, a first multiplexer (MUX 1) 447a, a second multiplexer (MUX 2) 447b, streaming encoder circuitry (streaming encoder) 448, Ethernet tunneler circuitry (Ethernet tunneler) 445, and at least one transmit buffer circuitry (TX buffer(s)) 449b.
  • PHY physical
  • MAC media access controller
  • MAC media access controller
  • the MAC 444, the PHY 442, and each synchronization circuit 441a, 441b may be implemented with conventional technology, e g., circuitry, used to implement such components, e.g., in an Ethernet-compliant device.
  • the MAC 444 and the PHY 442 are respectively a conventional Ethernet MAC and a conventional Ethernet PHY.
  • the PHY 442 is configured to perform physical layer processing on signals representing a media independent Ethernet frame to facilitate transmission and receipt of the Ethernet frame respectively to and from an Ethernet link 436 electrically coupled to the PHY 442.
  • an Ethernet link 436 may be between two ICNs, between an RF donor and an ICN, or between an ICN and an RU.
  • the MAC 444 is configured (a) to receive (e.g., from the second synchronization circuit 441b) a frame of first application layer data, encapsulate the first frame of application layer data into a first Ethernet payload, add a first Ethernet header including first Ethernet header data to the first Ethernet payload to form a first Ethernet frame, and transmit the first Ethernet frame to the PHY 442 and (b) to receive a second Ethernet frame from the PHY 442, extract second header data from a second Ethernet header of the second Ethernet frame, decapsulate (or extract) the second application layer data from a second Ethernet payload of the second Ethernet frame, and transmit (e.g., to the first synchronization circuit 441a) the second application layer data.
  • the MAC 444 (and/or other components of the transport l/F circuitry 400) is configured to generate error checking data (described elsewhere herein) for sequence data in a header of each streaming frame of service data (which is configured to be transmitted in an Ethernet frame to another DAS component through an Ethernet link) and to store the generated error checking data in the header of such streaming frame.
  • the MAC (and/or other components of the transport l/F circuitry 400) is configured to extract error checking data from a header of each streaming frame of service data and to perform error checking on sequence data in a header of each streaming frame of service data (configured to be transmitted in an Ethernet frame to other component(s) of the DAS component of which the transport l/F 400 is part).
  • the PHY 442 is configured to receive Ethernet frames of service data and Ethernet frames of synchronization data.
  • the PHY 442 is configured to transmit such Ethernet frames to the MAC 444.
  • the MAC 444 is configured to transmit synchronization data and streaming frames of service data to the first synchronization circuit 441a.
  • the first synchronization circuit 441a is configured to transmit streaming frames of service data (received from the MAC 444) to the streaming decoder 446; the first synchronization circuit 441a does not affect the service data.
  • the first synchronization circuit 441a is further configured to be or be part of a transparent clock or a boundary clock.
  • the first synchronization circuit 441a When a transparent clock, the first synchronization circuit 441a optionally adds a residence time at a node (in which the transport l/F circuitry 400 is located) to a correction field of the first synchronization data received (from the MAC 444) by the first synchronization circuit 441a and then transmits the synchronization data to the first multiplexer 447a. 5
  • the correction field data can be used to determine network delay.
  • the first synchronization circuit 441a acts as a master clock (or timing master) for component(s), e.g., ICN(s) 112 and/or RU(s) 106, subtended, i.e., downstream, from a component (e.g., an RF donor 114 or an ICN 112) including the first synchronization circuit 441a and optionally for component(s) upstream from the component including the first synchronization circuit when communicatively coupled to different port(s) of the component including the first synchronization circuit 441a.
  • component(s) e.g., ICN(s) 112 and/or RU(s) 106
  • the first synchronization circuit 441a acts as a master clock for components directly communicatively coupled to the component including the first synchronization circuit 441a; each ICN 112 acts as a timing master and a timing subordinate.
  • the boundary clock is implemented with a local clock in the node (e.g., each ICN 112 and optionally the RF donor 114) locked or synchronized using time or phase data, e.g., received pursuant to IEEE standard 1588, and optionally using a frequency derived from at least the first synchronization data or message and the time domain digital baseband IQ data, e.g., received pursuant to International Telecommunication Union (ITU) Telecommunication standardization Sector Synchronous Ethernet (SynchE).
  • synchronization data includes the time or phase data.
  • the first synchronization circuit 441a receives timing data (e.g., time or phase data and optionally a frequency reference), adjusts for delay using such timing data, and then using the timing data and the delay creates and transmits a new master time data.
  • timing data e.g., time or phase data and optionally a frequency reference
  • Each ICN 112 in the DAS may utilize a transparent clock, or a boundary clock (thus, serving as a timing master and a timing subordinate).
  • the streaming decoder circuitry 446 is configured to extract (from each streaming frame of service data) subframes of (a) time-domain digital baseband IQ data or (b) ALDNS.
  • the subframes of ALDNS are tunneled data.
  • the streaming decoder circuitry 446 is further configured to transmit each subframe of time-domain digital baseband IQ data to the at least one receive buffer 449a, and to transmit each subframe of ALDNS to the Ethernet detunneler 443.
  • more than one data channel may be used to communicatively couple the streaming decoder 446 to the Ethernet detunneler 443 and to convey data in parallel in the more than one data channel.
  • the first synchronization circuit 441 a is configured to transmit synchronization data to the first multiplexer 447a through an optional first communications link 440A.
  • more than one data channel may be used to communicatively couple the streaming decoder 446 to the at least one receive buffer 449a; each data channel is communicatively coupled to a unique receive buffer of the at least one receive buffer 449a.
  • the more than one data channel can be used to convey data in parallel to the receive buffers.
  • the at least one receive buffer 449a stores time-domain baseband IQ data
  • the at least one receive buffer 449a is configured to periodically transmit no more than a fixed amount, e.g., a block, of time-domain digital baseband IQ data, e.g., within a component of the DAS or to another component of the DAS, e.g., a donor or other component(s) of a donor including the transport l/F circuitry 400, or to an ICN 112.
  • the Ethernet detunneler 443 is configured to identify messages, e.g., messages of O-RAN data and messages of management data, in the ALDNS in one subframe and transmit each message to the first multiplexer 447a.
  • messages e.g., messages of O-RAN data and messages of management data
  • ALDNS in one subframe may contain more than one message or at least one message and data for at least other message; such data forms a fraction of message(s).
  • the Ethernet detunneler 443 identifies each complete message in a subframe, extracts each complete message from the subframe, and transmit each complete message to the first multiplexer 447a.
  • a subframe of ALDNS may comprise data that forms a fraction of a message (e.g., one, two, three, or more bytes of data).
  • the Ethernet detunneler 443 is also configured to generate message(s) from such data from two or more subframes of ALDNS, and to transmit such messages to the first multiplexer 447a.
  • the Ethernet detunneler 443 is further configured to perform error detection of the ALDNS, e.g., the O-RAN data and/or the management data in subframes of the Ethernet frame of service data, e.g., using a cyclic redundancy or parity bit check (CRC) on respectively CRC or parity bit data for such ALDNS.
  • the Ethernet detunneler 443 is further configured to extract such error checking data (used to perform the aforementioned error detection) from a subframe of ALDNS which is used to generate the error checking data.
  • the first multiplexer 447a is configured to transmit synchronization data and messages derived from the subframe(s) of ALDNS.
  • the synchronization data and the messages derived from subframe(s) of ALDNS are transmitted during different time periods, e.g., alternatively) over an Ethernet link to another component (e.g., of or external to the DAS fronthaul network), for example an O-RAN donor 122 or the management system.
  • the at least one transmit buffer 449b is configured to receive and store time-domain digital baseband IQ data (e.g., from routing function in an ICN 112 or a donor, or components thereof, for example a CPRI donor or an RF donor).
  • time-domain digital baseband IQ data e.g., from routing function in an ICN 112 or a donor, or components thereof, for example a CPRI donor or an RF donor.
  • the at least one transmit buffer 449b is further configured to transmit no more than a fixed amount, e.g., a block, of time-domain digital baseband IQ data to the streaming encoder 448.
  • the Ethernet tunneler circuitry 445 is configured to receive and buffer ALDNS (e.g., O-RAN data and/or management data), e.g., from the management system and/or an O- RAN donor.
  • ALDNS e.g., O-RAN data and/or management data
  • the Ethernet tunneler circuitry 445 is further configured to transmit, to the streaming encoder 448, a portion including no more than a fixed amount of ALDNS (e.g., no more than a fixed amount of bytes of data for example, one, two, three, or more bytes of data). Each portion may include a fraction of a message, a message, or more than one message.
  • the Ethernet tunneler circuitry 445 is configured to extract portions from of the message.
  • Each portion is no more than the fixed amount of ALDNS (e.g., no more than a fixed amount of bytes of data for example, one, two, three, or more bytes of data).
  • the Ethernet tunneler circuitry 445 transmits each portion to the streaming encoder circuitry 448. Each portion of such portions of the message is sequentially provided to the streaming encoder circuitry 448.
  • the streaming encoder circuitry 448 is configured to generate subframes comprising a portion (of the ALDNS) provided by the Ethernet tunneler circuitry and subframes including time-domain digital baseband data, e.g., having the same or different amount of data as each portion.
  • the streaming encoder circuitry 448 is further configured to form a streaming frame of service data including at least one subframe of time-domain digital base band data and at least one subframe of ALDNS (e.g., O-RAN data and/or management data), and a streaming frame header.
  • the streaming encoder circuitry 448 is further configured to transmit such streaming frames of service data to the second multiplexer circuitry 447b.
  • Each subframe of a portion of the ALDNS is a tunnel through which such data is streamed.
  • each subframe of a portion of the ALDNS comprises one, two, three, or more bytes of data.
  • the streaming encoder circuitry 448 is configured to generate an error checking data, e.g., CRC data or a parity bit, for each subframe of O-RAN data and/or management data.
  • the streaming encoder 448 is further configured to store the error checking data in the subframe of the O-RAN data and/or management data from which the error checking data is derived.
  • the second multiplexer circuitry 447b is configured to receive synchronization data, e.g., from a component (for example from the master timing entity, e.g., through a donor or component(s) of a donor including the transport l/F circuitry 400) which is part of or external to the DAS. 6
  • the second multiplexer circuitry 447b is further configured to transmit the synchronization data and streaming frames of service data (during at different time periods, e.g., alternatively) to the second synchronization circuit 441b.
  • the second synchronization circuit 441 b is configured to transmit streaming frames of service data (received from the streaming encoder 448) to the MAC 444; the second synchronization circuit 441 b does not affect the service data.
  • the second synchronization circuit 441b is further configured to be or be part of a transparent clock or a boundary clock.
  • the second synchronization circuity 441b adds a residence time of a node (in which the transport l/F circuitry 400 is located) to a correction field of synchronization data and to then transmit the synchronization data to the MAC 444.
  • a value stored in the correction field can be used to determine network delay.
  • the second synchronization circuit 441b acts as a master clock (or timing master) for component(s), e.g., ICN(s) 112 and/or RU(s) 106, subtended, i.e., downstream, from a component (e.g., an RF donor 114 or ICN 112) including the second synchronization circuit 441b and optionally for component(s) upstream from the component including the first synchronization circuit when communicatively coupled to different port(s) of the component including the second synchronization circuit 441b.
  • component(s) e.g., ICN(s) 112 and/or RU(s) 106
  • the second synchronization circuit 441b acts as a master clock for components directly communicatively coupled to the component including the second synchronization circuit 441b; each ICN 112 acts as a timing master.
  • the boundary clock is implemented by locking a local clock in each ICN 112 (and optionally the RF donor 114) using time or phase data, e.g., received pursuant to IEEE standard 1588, and a frequency reference, e.g.,
  • the second multiplexer is configured to receive Ethernet frames of synchronization data through an optional second communications link 440B. received pursuant to SynchE.
  • the second synchronization circuit 441b receives timing data (e.g., time or phase data and optionally a frequency reference), adjusts for delay using such timing data, and then using the timing data and the delay creates and transmits a new master time data.
  • the MAC 444 is configured to transmit the Ethernet frames of synchronization data and Ethernet frames of service data to the PHY 442.
  • the PHY 442 is configured to transmit such Ethernet frames of synchronization data and Ethernet frames of service data over the Ethernet link 436 to another component of the DAS.
  • the transport l/F circuitry 400 includes jitter buffering. If jitter buffering is included on a node in the network, the size and latency associated with the buffer increases with a maximum expected timing error between that node and other nodes of the network.
  • FIG. 5 illustrates a block diagram of one embodiment of an exemplary streaming frame 550 of service data and time-domain digital baseband IQ data.
  • the streaming frame 550 comprises a header 500H followed by a payload 500P.
  • the header 500H includes synchronization data and/or a sequence number which can be used to reassemble data in each subframe.
  • the sequence number may indicate a type of data and/or destination of each subframe of the Ethernet frame of service data 500C.
  • the payload 500P comprises subframes 500A, 500B of time-domain digital baseband IQ data derived from one or more radio frequency carriers, and subframes 500C of service data, which is not time-domain digital baseband in-phase and quadrature-phase (IQ) data originating from a donor including a split 8 interface with a base station.
  • FIG. 5 illustrates a payload comprising packets of time-domain digital baseband IQ data of a first RF carrier (or first carrier) and of a second RF carrier (or a second carrier). Solely for pedagogical purposes, it is assumed that the first RF carrier has a bandwidth twice the bandwidth of the second RF carrier; thus, FIG.
  • FIG. 5 illustrates a payload 500P comprising a number of subframes 500A of the time-domain digital baseband IQ data of the first RF carrier that is twice a number of subframes 500B of the time-domain digital baseband data of the second RF carrier.
  • FIG. 5 illustrates more subframes of time-domain digital baseband IQ data than subframes of service data. However, for example if the time-domain digital baseband IQ data is consuming a fraction, e.g., less of than half of bandwidth of the DAS fronthaul network, then the number of subframes of service data may equal or may be greater than the number of subframes of time-domain digital baseband IQ data.
  • FIG. 6 illustrates a flow diagram of one embodiment of a method 660 of generating an Ethernet frame with interleaved subframes of time-domain digital baseband IQ data and of O-RAN data and/or management data.
  • method 660 may be implemented in one or both the uplink path and the downlink path of the DAS.
  • FIG. 6 illustrates ALDN that is the O-RAN data (O-RAN user, control, and/or management plane data) and management data; however, the techniques of the method apply more generally to ALDN.
  • method 660 may be implemented in all or some of the DAS and DAS components described with respect to one or more of Figures 1- 4, and/or in other DAS and/or other DAS component implementations.
  • method 660 is performed in a component, e.g., a donor (for example an RF donor), of the DAS and is used to convey data to another component of the DAS communicatively coupled to the component through an Ethernet link.
  • a component e.g., a donor (for example an RF donor)
  • method 660 may utilize techniques described elsewhere herein, e.g., with respect to any of FIGS. 1-5.
  • O-RAN data and/or management data is received.
  • the management data means management data that is not O-RAN management data; optionally, the management data is received from a management system. (Alternatively, block 660A may be that: ALDNS is received.)
  • the O-RAN data and/or the management data is received by a component of the DAS.
  • the O-RAN data and the management data is received by an Ethernet tunneler 445 of the component of the DAS.
  • the O-RAN data and/or the management data is buffered.
  • the O-RAN data and/or the management data is buffered by the component of the DAS.
  • the O-RAN data and/or the management data is received by an Ethernet tunneler 445 of the component of the DAS.
  • the O-RAN data and/or the management data which has been buffered is transmitted in portions in a first-in first-out manner, wherein each portion comprises data no larger than a fixed data size.
  • the fixed data size may be one, two, three, or more bytes.
  • such O-RAN data and/or management data is transmitted within the component of the DAS (e.g., a donor, for example an RF donor, or by an ICN).
  • such O-RAN data and/or management data is transmitted from the Ethernet tunneler 445 to the streaming encoder 448.
  • each such O-RAN data and management data are in a form of a message.
  • time-domain digital baseband IQ data received.
  • the timedomain digital baseband IQ data is received at a first data rate.
  • such timedomain digital baseband IQ data is received by the component of the DAS which receives the O-RAN data and/or management.
  • such time-domain digital baseband IQ data is received by the at least one transmit buffer 449b in the component of the DAS.
  • the time-domain digital baseband IQ data is buffered.
  • O-RAN data and/or management data is buffered by the component of the DAS.
  • time-domain digital baseband IQ data is buffered by the at least one transmit buffer 449b.
  • time-domain digital baseband IQ data When the time-domain digital baseband data is buffered, then in block 660F no more than a second fixed amount of time-domain digital baseband IQ data is transmitted in portions.
  • Each portion of the buffered time-domain digital baseband IQ data comprises data no larger than a second fixed data size.
  • the second fixed data size may be a size of a block of in-phase or quadrature phase data.
  • the first and the second fixed data sizes may be the same or different.
  • O-RAN data and/or management data is transmitted within the component of the DAS.
  • time-domain digital baseband IQ data is transmitted by the at least one transmit buffer 449b to the streaming encoder 448 in the component of the DAS.
  • a streaming frame of service data including a frame header, one or more subframes of the time domain digital baseband IQ data, and one or more subframes of a portion of the O-RAN data and/or management data is generated, e.g., using the portions of time-domain digital baseband IQ data and the portions of buffered at least one of: O-RAN data and management data.
  • the data rate of data in each subframe is at the first data rate.
  • such streaming frame is generated by the component of the DAS which receives the O-RAN data and/or management.
  • such streaming frame is generated by the streaming encoder circuitry 448 in the component of the DAS.
  • an amount of buffered time-domain digital baseband IQ data is less than an amount of data in a subframe of time-domain digital baseband IQ data.
  • latency is reduced as the amount of time-domain digital baseband IQ data buffered is reduced.
  • error checking data (e.g., CRC data or a parity bit) for each subframe of O-RAN data and/or management data is generated.
  • error checking data is generated by the component of the DAS which receives the O-RAN data and/or management.
  • error checking data is generated by the streaming encoder circuitry 448 in the component of the DAS.
  • the error checking data for each subframe of O-RAN data and/or management data of subframe(s) of the streaming frame, is stored in the subframe whose data was used to generate the error checking data.
  • error checking data is stored by the component of the DAS which receives the O-RAN data and/or management.
  • error checking data is stored by the streaming encoder circuitry 448 in the component of the DAS.
  • an Ethernet frame of service data (/.e., including the streaming frame) is generated.
  • the Ethernet frame of service data and the Ethernet frame of synchronization data are generated.
  • the Ethernet frame of service data is generated by the component of the DAS.
  • the Ethernet frame of service data is generated by the MAC 444; the MAC 444 transmits such Ethernet frames to the PHY 442.
  • the Ethernet frame of service data is transmitted.
  • such Ethernet frames are transmitted by the component of the DAS to other component(s) of the DAS, e.g., an ICN or RU(s).
  • the Ethernet frames are transmitted by the PHY 442 to the other component(s) of the DAS.
  • the Ethernet frame including the streaming data is transmitted at the first data rate.
  • synchronization data is received.
  • such received synchronization data is at least one synchronization packet of data.
  • such synchronization data is received by the component of the DAS which receives the O-RAN data and/or management data.
  • such synchronization data is received by the second multiplexer 447b of the component of the DAS and transmitted to the second synchronization circuit 441 b.
  • the second multiplexer 447b is configured to transmit, e.g., alternatively, either the synchronization data or the streaming frame including one or more subframes of the time domain digital baseband IQ data and one or more subframes of the O-RAN data and/or management data.
  • the synchronization data is transmitted by the multiplexer to the second synchronization circuit 441 b.
  • the streaming frame including one or more subframes of the time domain digital baseband IQ data and one or more subframes of the O-RAN data and/or management data is transmitted from the second multiplexer 447b to the MAC 444 directly or through the second synchronization circuit 441 b.
  • second synchronization data is generated.
  • the second synchronization data is generated by the component of the DAS which receives the O-RAN data and/or management.
  • the second synchronization data is generated by the second synchronization circuit 441b which transmits the second synchronization data to the MAC 444.
  • the second synchronization data may be generated by using techniques described elsewhere herein for boundary or transparent clocks.
  • an Ethernet frame of second synchronization data is generated.
  • the Ethernet frame of synchronization data is generated by the component of the DAS which receives the O-RAN data and/or management.
  • the Ethernet frame of synchronization data is generated by the MAC 444; the MAC 444 transmits such Ethernet frames to the PHY 442.
  • the Ethernet frame of second synchronization data is transmitted.
  • such Ethernet frame is transmitted by the component of the DAS to other component(s) of the DAS.
  • the Ethernet frame is transmitted by the PHY 442 to the other component(s) of the DAS.
  • the Ethernet frame including the frame of synchronization data is transmitted at the first data rate.
  • FIG. 7 illustrates a flow diagram of one embodiment of a method 770 of extracting (a) time-domain digital baseband IQ data and O-RAN data and/or management data, and (b) synchronization data respectively from an Ethernet frame of service data and an Ethernet frame of synchronization data.
  • method 770 may be implemented in one or both of the uplink path and the downlink path of the DAS.
  • FIG. 7 illustrates ALDN that is the O-RAN data (O-RAN user, control, and/or management plane data) and management data; however, the techniques of the method apply more generally to ALDN.
  • method 770 may be implemented in all or some of the DAS and DAS components described with respect to one or more of Figures 1-4, and/or in other DAS and/or other DAS component implementations.
  • method 770 is performed in a component, e.g., a donor (for example an RF donor), of the DAS and is used to convey data to another component of the DAS communicatively coupled to the component through an Ethernet link.
  • a donor for example an RF donor
  • method 770 may utilize techniques described elsewhere herein, e.g., with respect to any of FIGS. 1-5.
  • an Ethernet frame of service data (which includes a streaming frame including at least one subframe of O-RAN data and/or management data and at least one subframe of time-domain digital baseband IQ data) is received.
  • such Ethernet frame of service data is received by a component of a DAS, e.g., a donor for example an RF donor, or by an ICN.
  • such Ethernet frame of service data is received by the MAC 444 through the PHY 442 of the component of the DAS and through an Ethernet link 446 from other component(s) of the DAS, e.g., an ICN or RU(s).
  • the Ethernet frame of service data includes subframes of data transmitted at the first data rate.
  • a streaming frame of service data is extracted from the Ethernet frame of service data.
  • such streaming frame of service data is extracted from the Ethernet frame by the component of a DAS.
  • such streaming frame is extracted from the Ethernet frame by the MAC 444 of the component of the DAS.
  • service data (e.g., time-domain digital baseband IQ data, and/or O- RAN data and management data) is extracted from each subframe of the streaming frame of service data.
  • Each subframe includes either O-RAN data and/or management data, or time-domain digital baseband IQ data.
  • O-RAN data and/or management data in a subframe may consist of a portion of a message of O-RAN data or a message of management data, e.g., one, two, three, or more bytes of data.
  • service data is extracted by the component of the DAS, for example, by the streaming decoder circuitry 446 in the component of the DAS.
  • the time-domain digital baseband IQ data is stored.
  • such time-domain digital baseband IQ data is stored within the component of a DAS.
  • such time-domain digital baseband IQ data is stored by the at least one receive buffer 449a of the component of the DAS.
  • time-domain baseband IQ data when time-domain baseband IQ data is stored, then periodically transmit no more than a fixed amount, e.g., a block, of time-domain digital baseband IQ data, e.g., within the component of the DAS network or to another component of the DAS, e.g., a donor or other component(s) of a donor including the transport l/F circuitry 400, or to an ICN 112.
  • a fixed amount e.g., a block
  • time-domain digital baseband IQ data is stored by the at least one receive buffer 449a of the component of the DAS.
  • error checking is performed for each subframe of O-RAN data and/or management data.
  • error checking data is extracted from each subframe of O-RAN and/or management data, and error checking is performed using the extracted error checking data (e.g., a parity bit or CRC data) and the data of the subframe from which the error checking data is extracted.
  • the error checking may be performed by with a parity or CRC algorithm.
  • error checking is performed within the component of a DAS.
  • such error checking is performed by the streaming decoder 446 or the Ethernet detunneler 443 of the component of the DAS.
  • the O-RAN data and/or the management data is buffered.
  • such O-RAN data and/or the management data is buffered by the component of a DAS.
  • such O-RAN data and/or the management data is buffered by the Ethernet detunneler 443 of the component of the DAS.
  • At least one of a message of O-RAN data and a message of management data are formed from the buffered O-RAN data and/or the management data.
  • O-RAN message and/or message of the management data are formed within the component of a DAS.
  • such message of O-RAN data and/or the message of management data are formed by the Ethernet detunneler 443.
  • message of O-RAN data and/or message of management data are transmitted either within the component of the DAS or to another component of the DAS.
  • message of O- RAN data and/or the message of management data are transmitted by the Ethernet detunneler 443 and through the first multiplexer 447a.
  • an Ethernet frame of synchronization data is received.
  • such Ethernet frame of synchronization data is received by the component of a DAS.
  • such Ethernet frame of synchronization data is received by the MAC 444 through the PHY 442 of the component of the DAS and through an Ethernet link 446 from other component(s) of the DAS, e.g., an ICN or RU(s).
  • the Ethernet frame of synchronization data includes synchronization data transmitted at the first data rate.
  • a synchronization message is extracted from the Ethernet frame of synchronization data.
  • such synchronization data is extracted by the component of a DAS.
  • such synchronization data is extracted by the MAC 444 of the component of the DAS.
  • a second synchronization message is generated.
  • the second synchronization message by the component of the DAS.
  • second synchronization message (received from the MAC 444) is generated by the first synchronization circuit 441a.
  • the second synchronization message may be generated by using techniques described elsewhere herein for boundary or transparent clocks.
  • the synchronization message is transmitted.
  • the synchronization message transmitted within the component of the DAS or by the component of the DAS to another component of the DAS.
  • such synchronization message is transmitted by the first synchronization circuit 441a, through the first multiplexer 447a, within the component of the DAS or to another component of the DAS.
  • FIG. 8 illustrates a flow diagram of one embodiment of a method 880 for streaming, in a fronthaul network of a DAS, time-domain digital baseband IQ data and optionally service data.
  • Embodiments of the invention permit transmitting, /.e., in a downlink streaming frame 550, a subset of time-domain data and optionally service data of a block of data prior to all of the block of data being received by the component, e.g., an RF donor 114 or an ICN 112, which is transmitting the subset.
  • method 880 may be implemented in all or some of the DAS and DAS components described with respect to one or more of Figures 1- 4, and/or in other DAS and/or other DAS component implementations.
  • method 880 is performed in a component, e.g., a donor (for example an RF donor) or an ICN, of the DAS and is used to convey data to another component of the DAS communicatively coupled to the component through an Ethernet link.
  • a component e.g., a donor (for example an RF donor) or an ICN
  • Method 660 may exhibit the aforementioned characteristics.
  • the transport l/F circuitry 400 in a downlink path from the Ethernet tunneler 445 and the transmit buffer(s) 449b to the PHY 442) also may exhibit this benefit.
  • the block of data means a CPRI frame of data, an eCPRI frame of data, a 5G NR resource block, or an O-RAN message.
  • a subset of data of a block of data is received from a CPRI baseband unit, an RF-interface base station, or an O-RAN distributed unit, wherein the subset of data includes an amount of data equal to a data threshold level, i.e., an amount of data which can be transmitted in the payload 500P of the streaming frame 550.
  • the data, in the block of data (and thus in the payload 500P), includes IQ data and optionally service data.
  • a payload 500P (of a streaming frame 550) is formed, on a first in first out basis, by time division multiplexing together subframes of downlink time-domain baseband IQ data 500A, 500B and optionally service data 500C that needs to be communicated to southbound RUs 106 and other ICNs 112 that are coupled respectively to a source RF donor 114 or a source ICN 112 via an Ethernet link 136.
  • the amount of the data in the payload 500P (of the streaming frame 550) is less than the amount of data in the block of data.
  • the streaming frame 550 upon forming the streaming frame 550, the streaming frame 550, including a payload 500P including the subset of data having an amount of data equal to the data threshold level, is transmitted in a downlink path. Such transmission occurs prior to receipt of all data in the block of data.
  • synchronization data is received.
  • the synchronization data or other synchronization data (which is formed using the received synchronization data) is transmitted in the downlink path.
  • Example 1 includes a method for tunneling data in a distributed antenna system (DAS), the method comprising: receiving at least one of: open radio access network (O- RAN) data and management data, wherein the O-RAN consists of O-RAN user data and O- RAN control data; buffering the at least one of: O-RAN data and management data; transmitting, in a first-in first-out manner, portions of buffered at least one of: O-RAN data and management data, wherein each portion of the buffered at least one of: O-RAN data and management data comprises data no larger than a first fixed data size; receiving timedomain digital baseband in-phase and quadrature phase (IQ) data; buffering the timedomain digital baseband IQ data; transmitting portions of buffered time-domain digital baseband IQ data, wherein each portion of the buffered time-domain digital baseband IQ data comprises data no larger than a second fixed data size; using the portions of timedomain digital baseband IQ data and the portions of buffered at least one of:
  • Example 2 includes the method of Example 1 , further comprising generating the second synchronization data by adding a residence time of a node to a correction field of the first synchronization data.
  • Example 3 includes the method of any of Examples 1-2, further comprising generating the second synchronization data from a local clock synchronized using time or phase data in the first synchronization data.
  • Example 4 includes the method of any of Examples 1-3, further comprising generating the second synchronization data from a local clock synchronized (a) using time or phase data in the first synchronization data and (b) using a frequency derived from at least the first synchronization data and the time-domain digital baseband IQ data.
  • Example 5 includes the method of any of Examples 1-4, wherein the time-domain digital baseband IQ data is received at a first data rate and the Ethernet frame including the streaming frame of service data is transmitted at the first data rate.
  • Example 6 includes the method of any of Examples 1-5, further comprising: generating error checking data for each subframe of the O-RAN data and/or management data; and storing the error checking data in a subframe whose data was used to generate the error checking data.
  • Example 7 includes the method of Example 6, wherein the error checking data comprises parity bit check data or cyclic redundancy check data.
  • Example 8 includes the method of any of Examples 1-7, where the first fixed data size is not equal to the second fixed data size.
  • Example 9 includes a method for tunneling data in a distributed antenna system (DAS), the method comprising: receiving an Ethernet frame including a streaming frame, wherein the streaming frame comprises at least one subframe of time-domain digital baseband in-phase and quadrature phase (IQ) data and at least one subframe of O-RAN data and/or management data wherein the O-RAN consists of O-RAN user data and O-RAN control data; extracting a streaming frame of service data from each subframe of the service data the Ethernet frame of service data; storing the time-domain digital baseband IQ data from each subframe; periodically transmitting no more than a fixed amount of time-domain digital baseband IQ data; buffering the O-RAN data and/or management data; using buffered O-RAN data and/or management data, forming at least one of: a message of O- RAN data and a message of management data; transmitting the at least one of: an O-RAN message and a message about management data; receiving an Ethernet frame of synchronization data; extracting a first
  • Example 10 includes the method of Example 9, further comprising generating the second synchronization message by adding a residence time of a node to a correction field of the first synchronization message.
  • Example 11 includes the method of any of Examples 9-10, further comprising generating the second synchronization message from a local clock synchronized using time or phase data in the first synchronization message.
  • Example 12 includes the method of any of Examples 9-11, further comprising generating the second synchronization message from a local clock synchronized (a) using time or phase data in the first synchronization message and (b) using a frequency derived from at least the first synchronization message and the time-domain digital baseband IQ data.
  • Example 13 includes the method of any of Examples 9-12, wherein the time-domain digital baseband IQ data is received at a first data rate and the Ethernet frame including the streaming frame of service data is transmitted at the first data rate.
  • Example 14 includes the method of any of Examples 9-13, further comprising performing error checking of each subframe of the O-RAN data and/or management data.
  • Example 15 includes the method of Example 14, wherein the error checking comprises parity bit checking or cyclic redundancy checking.
  • Example 16 includes an apparatus for tunneling data in a distributed antenna system (DAS), the apparatus comprising: circuitry configured to: receive at least one of: open radio access network (O-RAN) data and management data, wherein the O-RAN consists of O- RAN user data and O-RAN control data; buffer the at least one of: O-RAN data and management data; transmit, in a first-in first-out manner, portions of buffered at least one of: O-RAN data and management data, wherein each portion of the buffered at least one of: O- RAN data and management data comprises data no larger than a first fixed data size; receive time-domain digital baseband in-phase and quadrature phase (IQ) data; buffer the time-domain digital baseband IQ data; transmit portions of buffered time-domain digital baseband IQ data, wherein each portion of the buffered time-domain digital baseband IQ data comprises data no larger than a second fixed data size; using the portions of timedomain digital baseband IQ data and the portions of buffered at least one
  • Example 18 includes the apparatus of any of Examples 16-17, wherein the circuitry is further configured to generate the second synchronization data from a local clock synchronized using time or phase data in the first synchronization data.
  • Example 19 includes the apparatus of any of Examples 16-18, wherein the circuitry is further configured to generate the second synchronization data from a local clock synchronized (a) using time or phase data in the first synchronization data and (b) using a frequency derived from at least the first synchronization data and the time-domain digital baseband IQ data.
  • Example 20 includes the apparatus of any of Examples 16-19, wherein the timedomain digital baseband IQ data is received at a first data rate and the Ethernet frame including the streaming frame of service data is transmitted at the first data rate.
  • Example 21 includes the apparatus of any of Examples 16-20, wherein the circuitry is further configured to: generate error checking data for each subframe of the O-RAN data and/or management data; and store the error checking data in a subframe whose data was used to generate the error checking data.
  • Example 22 includes the apparatus of Example 21, wherein the error checking data comprises parity bit check data or cyclic redundancy check data.
  • Example 23 includes the apparatus of any of Examples 16-22, wherein the first fixed data size is not equal to the second fixed data size.
  • Example 24 includes an apparatus for tunneling data in a distributed antenna system (DAS), the apparatus comprising: circuitry configured to: receive an Ethernet frame including a streaming frame, wherein the streaming frame comprises at least one subframe of timedomain digital baseband in-phase and quadrature phase (IQ) data and at least one subframe of O-RAN data and/or management data, wherein the O-RAN consists of O-RAN user data and O-RAN control data; extract a streaming frame of service data from each subframe of the service data the Ethernet frame of service data; store the time-domain digital baseband IQ data from each subframe; periodically transmit no more than a fixed amount of time-domain digital baseband IQ data; buffer the O-RAN data and/or management data; using buffered O-RAN data and/or management data, form at least one of: a message of O-RAN data and a message of management data; transmit the at least one of: a message of O-RAN data and a message of management data; receive an Ethernet frame of synchronization data; extract a first
  • Example 25 includes the apparatus of Example 24, wherein the circuitry is further configured to generate the second synchronization message by adding a residence time of a node to a correction field of the first synchronization message.
  • Example 26 includes the apparatus of any of Examples 24-25, wherein the circuitry is further configured to generate the second synchronization message from a local clock synchronized using time or phase data in the first synchronization message.
  • Example 27 includes the apparatus of any of Examples 24-26, wherein the circuitry is further configured to generate the second synchronization message from a local clock synchronized (a) using time or phase data in the first synchronization message and (b) using a frequency derived from at least the first synchronization message and the timedomain digital baseband IQ data.
  • Example 28 includes the apparatus of any of Examples 24-27, wherein the timedomain digital baseband IQ data is received at a first data rate and the Ethernet frame including the streaming frame of service data is transmitted at the first data rate.
  • Example 29 includes the apparatus of any of Examples 24-28, wherein the circuitry is further configured to perform error checking of each subframe of the O-RAN data and/or management data.
  • Example 30 includes the apparatus of Example 29, wherein the error checking comprises parity bit checking or cyclic redundancy checking.
  • Example 31 includes a method for streaming, in a fronthaul network of a distributed antenna system (DAS), time-domain digital baseband in-phase and quadrature phase (IQ) data and optionally streaming data, the method comprising: receiving a subset of data, of a block of data, wherein the subset of data includes an amount of data equal to an amount of data which can be transmitted in a payload of a streaming frame; forming the streaming frame including the payload using data of the subset, received on a first in first out basis, by time division multiplexing together subframes of such data, wherein an amount of the data in the payload of the streaming frame is less than the amount of data in the block of data; upon forming the streaming frame, transmitting, in a downlink path of the fronthaul network of the DAS, the streaming frame including the payload; receiving synchronization data; and transmitting, in the downlink path of the fronthaul network of the DAS, the synchronization data or other synchronization data formed using the received synchronization data
  • Example 32 includes an apparatus streams, in a fronthaul network of a distributed antenna system (DAS), time-domain digital baseband in-phase and quadrature phase (IQ) data and optionally streaming data
  • the apparatus comprises circuitry configured to: receive a subset of data, of a block of data, wherein the subset of data includes an amount of data equal to an amount of data which can be transmitted in a payload of a streaming frame; form the streaming frame including the payload using data of the subset, received on a first in first out basis, by time division multiplexing together subframes of such data, wherein an amount of the data in the payload of the streaming frame is less than the amount of data in the block of data; upon forming the streaming frame, transmit, in a downlink path of the fronthaul network of the DAS, the streaming frame including the payload; receive synchronization data; and transmit, in the downlink path of the fronthaul network of the DAS, the synchronization data or other synchronization data formed using the received synchronization data.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

L'invention concerne des techniques de diffusion en continu de données de service avec des trames de diffusion en continu comprenant une ou des sous-trames de données O-RAN et/ou de données de gestion et une ou des sous-trames de données de bande de base numérique dans le domaine temporel. Les trames de diffusion en continu sont transportées dans un réseau fronthaul DAS configuré pour être mis en œuvre avec des liaisons Ethernet classiques.
PCT/US2024/028392 2023-06-05 2024-05-08 Techniques pour diminuer la latence dans un système d'antenne distribué Pending WO2024253796A1 (fr)

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Citations (5)

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Publication number Priority date Publication date Assignee Title
US8346091B2 (en) * 2009-04-29 2013-01-01 Andrew Llc Distributed antenna system for wireless network systems
US20210068110A1 (en) * 2012-10-31 2021-03-04 Commscope Technologies Llc Digital baseband transport in telecommunications distribution systems
US20210234746A1 (en) * 2018-09-19 2021-07-29 Solid, Inc. Distributed antenna system-based on time sensitive network
US20220417876A1 (en) * 2021-06-25 2022-12-29 Commscope Technologies Llc Distributed antenna system implemented over open radio access network
US20230067773A1 (en) * 2021-09-01 2023-03-02 Adrf Korea, Inc. Das for multi-frequency band and multi-carrier based on o-ran standard

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8346091B2 (en) * 2009-04-29 2013-01-01 Andrew Llc Distributed antenna system for wireless network systems
US20210068110A1 (en) * 2012-10-31 2021-03-04 Commscope Technologies Llc Digital baseband transport in telecommunications distribution systems
US20210234746A1 (en) * 2018-09-19 2021-07-29 Solid, Inc. Distributed antenna system-based on time sensitive network
US20220417876A1 (en) * 2021-06-25 2022-12-29 Commscope Technologies Llc Distributed antenna system implemented over open radio access network
US20230067773A1 (en) * 2021-09-01 2023-03-02 Adrf Korea, Inc. Das for multi-frequency band and multi-carrier based on o-ran standard

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