Front-Haul Link Selection in a Wireless Communication System

Abstract

A method, system, and computer program product for selecting a fronthaul link in a wireless communication system. One or more link delays are determined. The link delays are associated with any one or more of a plurality of communication links communicatively connecting a first communication device and a second communication device. A communication link transmission priority of the communication links is determined using the determined link delays for transmission of one or more data packets. A list of prioritized communication links is generated. At least one communication link is selected among the prioritized communication links for transmission of the data packets between the first communication device and the second communication device. The data packets are transmitted between the first communication device and the second communication device using the selected communication link.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims priority to U.S. Patent Application No. 17 / 403,419, filed Aug. 16, 2021, by Reddy et al. entitled “Front - haul Link Selection in a Wireless Communication System,” the disclosure of which is hereby incorporated by reference in its entirety.

[0002] In some implementations, the present subject matter relates to a telecommunication system, and more particularly to the selection of a front - haul link based on an awareness of whether a wireless channel in a wireless communication system, such as, for example, 5G New Radio (“NR”), is sensitive to delay and a measured front - haul link delay.

Background Art

[0003] In today's world, cellular networks provide on - demand communication capabilities to individuals and corporations. Typically, a cellular network is a wireless network that can be dispersed over land areas called cells. Each such cell is served by at least one fixed - location transceiver called a cell site or base station. Each cell can use a different set of frequencies from its neighboring cells to avoid interference and provide improved services within the cell. When cells cooperate with each other, they provide wireless coverage over a wide geographic area, enabling a large number of mobile phones, and / or other wireless devices or portable transceivers to communicate with each other and with fixed transceivers or telephones anywhere within the network. Such communication is carried out through base stations and is achieved even when a mobile transceiver is moving through two or more cells during transmission. Because major wireless communication providers have deployed such cell sites around the world, it has become possible to connect communication mobile phones and mobile computing devices to the public switched telephone network and the public Internet.

[0004] A mobile phone is a portable telephone that can receive and / or make telephone and / or data communications through a cell site or transmitting tower by transferring signals between mobile phones using radio waves. Considering a large number of mobile phone users, the current mobile phone network provides limited shared resources. In that regard, cell sites and handsets can change frequencies and use low-power transmitters to reduce interference and enable simultaneous use of the network by a large number of callers. Coverage by cell sites can depend on a specific geographical location and / or the number of users who may use the network. For example, in a city, a cell site may have a range of up to about 1 / 2 mile, in rural areas, the range can be up to 5 miles, and in some areas, users can receive signals from cell sites up to 25 miles away.

[0005] The following are some examples of digital cellular technologies used by communication providers. Global System for Mobile Communications (''GSM'') for mobile communication, General Packet Radio Service (''GPRS''), cdmaOne, CDMA2000, Evolution-Data Optimized (''EV-DO''), Enhanced Data rates for GSM Evolution (''EDGE''), Universal Mobile Telecommunications System (''UMTS''), Digital Enhanced Cordless Telecommunications (''DECT''), Digital AMPS (''IS-136 / TDMA''), and Integrated Digital Enhanced Network (''iDEN''). Long Term Evolution, i.e., 4G LTE, developed by the 3rd Generation Partnership Project (''3GPP (registered trademark)'') standards body, is a high-speed data wireless communication standard for mobile phones and data terminals. Currently, the 5G standard is being developed and deployed. 3GPP cellular technologies such as LTE and 5G NR are evolved from earlier generations of 3GPP technologies such as GSM / EDGE and UMTS / HSPA digital cellular technologies, enabling increased capacity and speed by using different radio interfaces along with improvements in the core network.

[0006] A cellular network can be divided into a radio access network and a core network. The radio access network (RAN) may include network functions capable of performing radio layer communication processing. The core network may include network functions capable of processing upper layer communication, such as Internet Protocol (IP), transport layer, and application layer. In some cases, RAN functions can be divided into a baseband unit function and a radio unit function. For example, a radio unit connected to a baseband unit via a fronthaul network can be responsible for lower layer processing of the radio physical layer, and the baseband unit can be responsible for upper layer radio protocols such as MAC and RLC.

[0007] The fronthaul network can be sensitive to latency and jitter. The latency and jitter introduced by switches in the fronthaul network can have an undesirable impact on the functions of the communication system. In a redundant fronthaul network, each communication link may have various latencies and / or jitters depending on the way data packets are transmitted, which can further complicate communication. SUMMARY OF THE INVENTION

[0008] In some implementations, the subject matter relates to a method implemented by a computer for selecting a fronthaul link in a wireless communication system. The method may include determining one or more link delays. The link delay may be associated with any one or more of a plurality of communication links communicatively connecting a first communication device and a second communication device. The method may further include using the determined one or more link delays to determine a communication link transmission priority order of the communication links for transmission of one or more data packets, and generating a list of the one or more prioritized communication links. The method may also include selecting at least one communication link from among the prioritized communication links for transmission of one or more data packets between the first communication device and the second communication device, and transmitting the data packets between the first communication device and the second communication device using the selected communication link.

[0009] In some implementations, the subject matter may include any one or more of the following optional features. Link delay At least any one of determining, determining the communication link transmission priority order, selecting, and transmitting may be performed by a base station. The base station may include at least any one of the following communication components, namely, a radio interface unit and a distributed unit. The distributed unit may be configured to interface with the radio interface unit for transmission of data packets.

[0010] In some implementations, the first communication device may include a distributed unit, and the second communication device may include a radio interface unit. The link delay may include at least one first link delay associated with the transmission of a data packet from the distributed unit to the radio interface unit, at least one second link delay associated with the transmission of a data packet from the radio interface unit to the distributed unit, and at least any one of any combination thereof. The downlink path delay of each available link may be measured by the distributed unit. The uplink path delay of each available link may be measured by the radio interface unit. One or more timestamps associated with the uplink path may be provided to the distributed unit to determine the uplink path delay as the measured uplink path. In some implementations, the method may include determining the delay sensitivity associated with the transmission of a data packet on the communication link. The delay sensitivity may be determined based on at least any one of the downlink path and uplink path delays that do not exceed at least one predetermined delay threshold. The communication link transmission priority may be determined using at least any one of the downlink path and uplink path delays and the determined delay sensitivity.

[0011] In some implementations, determining the communication link transmission priority may include assigning one or more weighting factors to at least any one of the downlink path and uplink path delays and the determined delay sensitivity. Generating a list may include generating a weighted list of prioritized communication links using the assigned weighting factors.

[0012] In some implementations, the method may include receiving, by the second communication device, a control plane message from the first communication device on a selected communication link, and transmitting, by the second communication device, a user plane message to the first communication device on the selected communication link.

[0013] In some implementations, the method may include receiving, by a second communication device, a control plane message from a first communication device on a selected communication link, and switching, by the second communication device, to a communication link selected from among at least another communication link of a plurality of communication links for transmission of a user plane message from the second communication device to the first communication device.

[0014] In some implementations, each link of the plurality of communication links may be associated with an Ethernet port of at least one of the first communication device and the second communication device and may be identified by an extended antenna carrier identifier.

[0015] A non-transitory computer program product (i.e., a physically embodied computer program product) that stores instructions for causing at least one data processor to perform the operations herein is also described, when executed by one or more data processors of one or more computing systems. Similarly, a computer system may be described that includes one or more data processors and a memory connected to the one or more data processors. The memory can store, temporarily or permanently, instructions for causing at least one processor to perform any one or more of the operations described herein. Additionally, the method may be implemented by one or more data processors within a single computing system or distributed across two or more computing systems. Such computing systems may be connected by one or more connections including, but not limited to, connections over a network (e.g., the Internet, a wireless wide area network, a local area network, a wide area network, a wired network, etc.), direct connections between any one or more of a plurality of computing systems, etc., and can exchange data and / or commands or other instructions, etc.

[0016] Details of one or more variations of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter described in this specification will be apparent from the description and drawings, and from the claims.

[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate specific embodiments of the subject matter disclosed herein and, together with the description, serve to explain some of the principles associated with the disclosed implementations. **Brief Description of the Drawings**

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[0038] The present subject matter can provide systems and methods that can be implemented in a lower layer split architecture of a wireless communication system. Such systems can include various wireless communication systems, such as 5G New Radio communication systems and Long Term Evolution communication systems.

[0039] One or more aspects of the present subject matter can be incorporated into the transmission and / or reception components of a base station (e.g., gNodeB, eNodeB, etc.) within such a communication system. The following is an overview of the Long Term Evolution communication system and the 5G New Radio communication system.

[0040] I. Long Term Evolution Communication System Figures 1a through 1c and 2 show a typical conventional Long Term Evolution (LTE) communication system 100 in conjunction with its various components. The LTE system or 4G LTE, as it is commercially known, is operated by a high-speed data wireless communication standard for mobile phones and data terminals. This standard is based on GSM / EDGE (Global System for Mobile Communications / Enhanced Data Rates for GSM Evolution) as well as UMTS / HSPA (Universal Mobile Telecommunications System / High Speed Packet Access) network technologies. This standard was developed by the 3GPP (3rd Generation Partnership Project).

[0041] As shown in FIG. 1a, the system 100 may include an evolved Universal Terrestrial Radio Access Network (EUTRAN) 102, an evolved Packet Core (EPC) 108, and a Packet Data Network (PDN) 101, and EUTRAN 102 and EPC 108 provide communication between user equipment 104 and PDN 101. EUTRAN 102 may include a plurality of evolved Node Bs (eNodeB or ENODEB or enodeb or eNB) or base stations 106 (a, b, c) (shown in FIG. 1b) that provide communication capabilities to a plurality of user equipments 104 (a, b, c). The user equipment 104 may be a mobile phone, a smart phone, a tablet, a personal computer, a personal digital assistant (PDA), a server, a data terminal, and / or any other type of user equipment, and / or any combination thereof. The user equipment 104 can connect to the EPC 108 through any eNodeB 106 and ultimately to the PDN 101. Typically, the user equipment 104 can connect to the eNodeB 106 that is closest in terms of distance. In the LTE system 100, EUTRAN 102 and EPC 108 cooperate to provide connectivity, mobility, and services to the user equipment 104.

[0042] Figure 1b shows further details of the network 100 shown in Figure 1a. As described above, the EUTRAN 102 includes a plurality of eNodeBs 106, also known as cell sites. The eNodeB 106 provides radio functions and executes major control functions including scheduling of air-link resources or radio resource management, active mode mobility or handover, and service admission control. The eNodeB 106 is responsible for the selection of a mobility management entity (MME shown in Figure 1c) that takes care of the user equipment 104 and protocol functions such as header compression and encryption. The eNodeBs 106 that make up the EUTRAN 102 cooperate with each other for radio resource management and handover.

[0043] The communication between the user equipment 104 and the eNodeB 106 is performed via an air interface 122 (also known as the "LTE-Uu" interface). As shown in Figure 1b, the air interface 122 provides communication between the user equipment 104b and the eNodeB 106a. The air interface 122 uses orthogonal frequency division multiple access ("OFDMA") and single carrier frequency division multiple access ("SC-FDMA"), which is a variation of OFDMA, for the downlink and uplink, respectively. OFDMA enables the use of multiple known antenna technologies such as Multiple Input Multiple Output ("MIMO").

[0044] The air interface 122 uses various protocols including radio resource control ("RRC") for signaling between the user equipment 104 and the eNodeB 106 and non-access stratum ("NAS") for signaling between the user equipment 104 and the MME (shown in Figure 1c). In addition to signaling, user traffic is transferred between the user equipment 104 and the eNodeB 106. Both signaling and traffic within the system 100 are carried by physical layer ("PHY") channels.

[0045] A plurality of eNodeBs 106 can be interconnected with each other using the X2 interfaces 130(a, b, c). As shown in FIG. 1a, the X2 interface 130a provides the interconnection between eNodeB 106a and eNodeB 106b, the X2 interface 130b provides the interconnection between eNodeB 106a and eNodeB 106c, and the X2 interface 130c provides the interconnection between eNodeB 106b and eNodeB 106c. An X2 interface can be established between two eNodeBs to provide the exchange of signals that can include not only handover-related information but also load-related information and interference-related information. The eNodeB 106 communicates with the evolved packet core 108 via the S1 interfaces 124(a, b, c). The S1 interface 124 can be split into two interfaces, one for the control plane (illustrated as the control plane interface (S1-MME interface) 128 in FIG. 1c) and the other for the user plane (illustrated as the user plane interface (S1-U interface) 125 in FIG. 1c).

[0046] The EPC 108 establishes and enforces the quality of service (“QoS”) of user services and enables the user equipment 104 to maintain a consistent Internet Protocol (“IP”) address while moving. Note that each node within the network 100 has its own IP address. The EPC 108 is designed to interact with legacy radio networks. The EPC 108 is also designed to separate the control plane (i.e., signaling) and the user plane (i.e., traffic) in the core network architecture, which allows for further flexibility in implementation and independent scalability of control functions and user data functions.

[0047] The architecture of EPC108 is dedicated to packet data and is shown in more detail in Figure 1c. EPC108 includes a Serving Gateway (S-GW) 110, a PDN Gateway (P-GW) 112, a Mobility Management Entity (MME) 114, a Home Subscriber Server (HSS) 116 (the subscriber database of EPC108), and a Policy Control and Charging Rules Function (PCRF) 118. Some of these (such as S-GW, P-GW, MME, HSS, etc.) are often combined into nodes according to the manufacturer's implementation.

[0048] The S-GW110 functions as an IP packet data router and is the bearer path anchor for user equipment in EPC108. Thus, when the user equipment moves from one eNodeB 106 to another eNodeB 106 while in motion, the S-GW110 remains the same and the bearer path towards the EUTRAN102 is switched to communicate with the new eNodeB responsible for the user equipment 104. When the user equipment 104 moves to the domain of another S-GW110, the MME114 transfers all of the user equipment's bearer paths to the new S-GW. The S-GW110 establishes the bearer path for the user equipment to one or more P-GW112. When downstream data is received for an idle user equipment, the S-GW110 buffers the downstream packets and requests the MME114 to find and re-establish the bearer path through the EUTRAN102 to reach the EUTRAN102.

[0049] P-GW 112 is the gateway between the EPC 108 (as well as the user equipment 104 and the EUTRAN 102) and the PDN 101 (illustrated in Figure 1a). P-GW 112 functions as a router for user traffic and executes functions on behalf of the user equipment. These include IP address allocation for the user equipment, packet filtering of downstream user traffic to ensure placement on an appropriate bearer path, and enforcement of downstream QoS including data rate. Depending on the services utilized by the subscriber, there may be multiple user data bearer paths between the user equipment 104 and the P-GW 112. A subscriber can utilize services on a PDN served by a separate P-GW, in which case the user equipment has at least one bearer path established towards each P-GW 112. During a handover of the user equipment from one eNodeB to another, if the S-GW 110 also changes, the bearer path from the P-GW 112 is switched to the new S-GW.

[0050] The MME 114 manages the user equipment 104 within the EPC 108, which includes management of subscriber authentication, maintenance of context for the authenticated user equipment 104, establishment of data bearer paths within the network for user traffic, and tracking of the location of idle mobile bodies not detached from the network. In the case of an idle user equipment 104 that needs to reconnect to the access network to receive downstream data, the MME 114 initiates paging to find the user equipment and re-establishes a bearer path through the EUTRAN 102 to reach the EUTRAN 102. The MME 114 is selected by the eNodeB 106 for a particular user equipment 104, from which the user equipment starts system access. For the purposes of load distribution and redundancy, the MME is typically part of a group of MMEs within the EPC 108. In the establishment of the user's data bearer path, the MME 114 plays the role of selecting the P-GW 112 and the S-GW 110 that form the ends of the data path through the EPC 108.

[0051] PCRF 118 is responsible for policy control decision-making and controls the flow-based charging function in the policy control enforcement function (referred to as "PCEF") existing in P-GW 110. PCRF 118 provides QoS authorization (QoS class identifier (referred to as "QCI") and bit rate). The QoS authorization determines how a specific data flow is handled by the PCEF and ensures that this is in line with the user's subscription profile.

[0052] As described above, the IP service 119 is provided by the PDN 101 (illustrated in FIG. 1a).

[0053] FIG. 1d shows a typical structure of eNodeB 106. eNodeB 106 may include at least one remote radio head (RRH) 132 (usually three RRHs 132 may exist) and a baseband unit (BBU) 134. RRH 132 may be connected to antenna 136. RRH 132 and BBU 134 may be connected using an optical interface compliant with the specifications of the Common Public Radio Interface (CPRI) 142. The operation of eNodeB 106 may be characterized using the following standard parameters (and specifications), namely, radio frequency band (Band 4, Band 9, Band 17, etc.), bandwidth (5, 10, 15, 20 MHz), access method (downlink: OFDMA, uplink: SC-OFDMA), antenna technology (downlink: 2×2 MIMO, uplink: 1×2 single input multiple output (SIMO)), number of sectors (maximum 6), maximum transmit power (60 W), maximum transmit rate (downlink: 150 Mb / s, uplink: 50 Mb / s), S1 / X2 interface (1000Base-SX, 1000Base-T), and mobile environment (maximum 350 km / h). BBU 134 can be responsible for digital baseband signal processing, termination of S1 line, termination of X2 line, call processing, and monitoring and control processing. IP packets received from EPC 108 (not shown in FIG. 1d) may be modulated into digital baseband signals and transmitted to RRH 132. Conversely, digital baseband signals received from RRH 132 may be demodulated into IP packets for transmission to EPC 108.

[0054] RRH 132 can transmit and receive wireless signals using antenna 136. RRH 132 can convert digital baseband signals from BBU 134 into radio frequency (RF) signals (using converter (CONV) 140) and power amplify them (using amplifier (AMP) 138) for transmission to user equipment 104 (not shown in FIG. 1d). Conversely, RF signals received from user equipment 104 are amplified (using AMP 138) and converted into digital baseband signals for transmission to BBU 134 (using CONV 140).

[0055] Figure 2 shows further details of a typical eNodeB 106. The eNodeB 106 includes multiple layers, namely, LTE layer 1 202, LTE layer 2 204, and LTE layer 3 206. LTE layer 1 includes the physical layer ("PHY"). LTE layer 2 includes medium access control ("MAC"), radio link control ("RLC"), and packet data convergence protocol ("PDCP"). LTE layer 3 includes various functions and protocols including radio resource control ("RRC"), dynamic resource allocation, eNodeB measurement, configuration, and provisioning, radio admission control, connection mobility control, and radio resource management ("RRM"). The RLC protocol is an automatic repeat request ("ARQ") fragmentation protocol used across the cellular air interface. The RRC protocol processes the control plane signaling of LTE layer 3 between the user equipment and the EUTRAN. RRC includes functions for connection establishment and release, broadcast of system information, radio bearer establishment / reconfiguration and release, RRC connection mobility procedures, paging notification and release, and outer loop power control. PDCP performs IP header compression and decompression, transfer of user data, and maintenance of the sequence numbers of radio bearers. The BBU 134 shown in FIG. 1d may include LTE layers L1 - L3.

[0056] One of the main functions of the eNodeB 106 is radio resource management, which includes scheduling of both uplink and downlink air interface resources for the user equipment 104, control of bearer resources, and admission control. The eNodeB 106, acting as an agent of the EPC 108, is responsible for transferring paging messages used to find mobile bodies in the idle state. The eNodeB 106 also transmits common control channel information over the air, header compression, encryption and decryption of user data transmitted over the air, handover reports, and establishment of trigger criteria. As described above, the eNodeB 106 can cooperate with other eNodeBs 106 on the X2 interface for the purposes of handover and interference management. The eNodeB 106 communicates with the MME of the EPC via the S1-MME interface and communicates with the S-GW using the S1-U interface. Furthermore, the eNodeB 106 exchanges user data with the S-GW on the S1-U interface. The eNodeB 106 and the EPC 108 have a many-to-many relationship to support load distribution and redundancy between the MME and the S-GW. The eNodeB 106 selects one MME from a group of MMEs so that the load can be distributed by multiple MMEs to avoid congestion.

[0057] II. 5G NR Radio Communication Network In some implementations, the subject matter relates to a 5G New Radio (NR) communication system. 5G NR is the next generation telecommunications standard beyond the 4G / IMT-Advanced standard. 5G networks provide higher capacity than current 4G, enabling an increase in the number of mobile broadband users per area unit and allowing for more and / or unlimited gigabyte-scale data consumption per month and per user. As a result, users can stream high-definition media for hours a day using a mobile device, even without a Wi-Fi network. 5G networks have improved device-to-device communication support, lower cost, lower latency than 4G devices, and less battery consumption. Such networks have data rates of tens of megabits per second for a large number of users, a data rate of 100 Mb / s for metropolitan areas, 1 Gb / s simultaneously for users within a limited area (e.g., an office floor), support for a large number of simultaneous connections in wireless sensor networks, improved spectral efficiency, improved coverage, improved signaling efficiency, a latency of 1 to 10 ms, and reduced latency compared to existing systems.

[0058] Figure 3 shows a typical virtual radio access network 300. Network 300 can provide communication between various components including a base station (e.g., eNodeB, gNodeB) 301, a radio device 307, a central unit 302, a digital unit 304, and a radio apparatus 306. Components within system 300 can be communicatively connected to the core using a backhaul link 305. The central unit ("CU") 302 can be communicatively connected to the distributed unit ("DU") 304 using a midhaul connection 308. The radio frequency ("RU") component 306 can be communicatively connected to the DU 304 using a fronthaul connection 310.

[0059] In some implementations, CU302 can provide intelligent communication capabilities to one or more DU units 308. Units 302, 304 can include one or more base stations, macro base stations, micro base stations, remote radio heads, etc., and / or any combination thereof.

[0060] In a lower layer split architecture environment, the CPRI bandwidth requirement of NR can be several hundred Gb / s. CPRI compression can be implemented in the DU and RU (shown in Figure 3). In a 5G communication system, the compressed CPRI over an Ethernet frame is called eCPRI, which is the recommended fronthaul network. This architecture can enable the standardization of fronthaul / midhaul, which can include upper layer split (e.g., Option 2 or Option 3-1 (upper / lower RLC split architecture)) and fronthaul (Option 7) with an L1 split architecture.

[0061] In some implementations, the lower layer split architecture (e.g., Option 7) can include a receiver in the uplink, joint processing across multiple transmission points (TPs) for both DL / UL, and transport bandwidth and latency requirements to facilitate deployment. Further, the lower layer split architecture of the present subject matter can include a split between cell level processing and user level processing, which can include cell level processing in a remote unit (“RU”) and user level processing in the DU. Further, using the lower layer split architecture of the present subject matter, frequency domain samples can be transferred via an Ethernet fronthaul, and the frequency domain samples can be compressed for fronthaul bandwidth reduction.

[0062] Figure 4 shows a typical communication system 400 that can implement 5G technology and provide its users with the use of a higher (e.g., greater than 10 GHz) frequency band. System 400 can include a macrocell 402 and small cells 404 and 406.

[0063] Mobile device 408 may be configured to communicate with any one or more of small cells 404, 406. System 400 can enable the division of the control plane (C-plane) and the user plane (U-plane) between macro cell 402 and small cells 404, 406, where the C-plane and the U-plane utilize different frequency bands. In particular, small cells 402, 404 may be configured to utilize a higher frequency band when communicating with mobile device 408. Macro cell 402 can utilize an existing cellular band for C-plane communication. Mobile device 408 may be communicatively connected via U-plane 412, and a small cell (e.g., small cell 406) can provide a higher data rate and more flexible / cost / energy-efficient operation. Macro cell 402 can maintain good connectivity and mobility via C-plane 410. Further, in some cases, LTE PUCCH and NR PUCCH may be transmitted on the same frequency.

[0064] Figure 5a shows a typical 5G wireless communication system 500 according to some implementations of the present subject matter. System 500 may be configured to have a lower layer split architecture according to Option 7-2. System 500 may include a core network 502 (e.g., 5G core) and one or more gNodeBs (or gNBs), and a gNB may have a centralized unit gNB-CU. gNB-CU may be logically split into a control plane part (gNB-CU-CP) 504 and one or more user plane parts (gNB-CU-UP) 506. The control plane part 504 and the user plane part 506 may be configured to be communicatively connected using an E1 communication interface 514 (as specified in the 3GPP standard). The control plane part 504 may be configured to be responsible for executing the RRC protocol and the PDCP protocol of the radio stack.

[0065] The control plane part and the user plane parts 504, 506 of the gNB's central unit can be configured to be communicatively connected to one or more distributed units (DUs) 508, 510 according to a lower layer split architecture. The distributed units 508, 510 can be configured to execute the upper parts of the RLC, MAC, and PHY layer protocols of the radio stack. The control plane part 504 can be configured to be communicatively connected to the distributed units 508, 510 using the F1-C communication interface 516, and the user plane part 506 can be configured to be communicatively connected to the distributed units 508, 510 using the F1-U communication interface 518. The distributed units 508, 510 can be connected to one or more remote radio units (RUs) 512 via a fronthaul network 520 (which may include one or more switches, links, etc.), and the one or more remote radio units (RUs) 512 communicate with one or more user devices (not shown in FIG. 5a). The remote radio unit 512 executes the lower part of the PHY layer protocol and can be configured to provide antenna capabilities to the remote unit for communication with user devices (similar to the above description related to FIGS. 1a to 2).

[0066] FIG. 5b shows a typical layer architecture 530 of a split gNB. The architecture 530 can be implemented in the communication system 500 shown in FIG. 5a, which can be configured as a virtualized distributed radio access network (RAN) architecture, whereby the layer L1, L2, L3 and radio processing can be virtualized and distributed among the central unit, the distributed unit, and the radio unit. As shown in FIG. 5b, the gNB-DU 508 can be communicatively connected to the gNB-CU-CP control plane part 504 (also shown in FIG. 5a) and the gNB-CU-UP user plane part 506. Each of the components 504, 506, 508 can be configured to include one or more layers.

[0067] gNB-DU 508 may include the RLC, MAC, and PHY layers, as well as various communication sub-layers. These may include the F1 application protocol (F1-AP) sub-layer, the GPRS tunneling protocol (GTPU) sub-layer, the stream control transmission protocol (SCTP) sub-layer, the user datagram protocol (UDP) sub-layer, and the internet protocol (IP) sub-layer. As described above, the distributed unit 508 may be communicatively connected to the control plane part 504 of the central unit, which may also include the F1-AP, SCTP, and IP sub-layers, as well as the radio resource control, and PDCP control (PDCP-C) sub-layers. Furthermore, the distributed unit 508 may also be communicatively connected to the user plane part 506 of the gNB's central unit. The user plane part 506 may include the service data adaptation protocol (SDAP), PDCP user (PDCP-U), GTPU, UDP, and IP sub-layers.

[0068] Figure 5c shows a typical functional split in the gNB architecture shown in Figures 5a to 5b. As shown in Figure 5c, gNB-DU 508 may be communicatively connected to gNB-CU-CP 504 and GNB-CU-UP 506 using the F1-C communication interface. gNB-CU-CP 504 and GNB-CU-UP 506 may be communicatively connected using the E1 communication interface. The upper part of the PHY layer (or layer 1) may be executed by gNB-DU 508, while the lower part of the PHY layer may be executed by the RU (not shown in Figure 5c). As shown in Figure 5c, the RRC part and the PDCP-C part may be executed by the control plane part 504, and the SDAP part and the PDCP-U part may be executed by the user plane part 506.

[0069] Some of the functions of the PHY layer in a 5G communication network may include error detection on the transport channel and indication to the upper layer, FEC encoding / decoding of the transport channel, hybrid ARQ soft combining, rate matching of the encoded transport channel to the physical channel, mapping of the encoded transport channel to the physical channel, power weighting of the physical channel, modulation and demodulation of the physical channel, frequency and time synchronization, radio characteristic measurement and indication to the upper layer, MIMO antenna processing, digital and analog beamforming, RF processing, and other functions.

[0070] The MAC sublayer of layer 2 can perform beam management, random access procedures, mapping of logical channels to transport channels, concatenation of multiple MAC service data units (SDUs) belonging to one logical channel into a transport block (TB), multiplexing / demultiplexing of SDUs belonging to logical channels to / from the TB passed to / from the physical layer on the transport channel, scheduling information reporting, error correction by HARQ, priority handling between logical channels of one UE, priority handling between UEs by dynamic scheduling, transport format selection, and other functions. The functions of the RLC sublayer may include transfer of upper layer packet data units (PDUs), error correction by ARQ, rearrangement, duplication, and protocol error detection of data PDUs, re-establishment, etc. The PDCP sublayer can be responsible for transfer of user data, various functions during re-establishment procedures, retransmission of SDUs, SDU discard in the uplink, transfer of control plane data, and others.

[0071] The RRC sublayer of layer 3 can perform broadcast of system information to the NAS and AS, establishment, maintenance, and release of RRC connections, security, establishment, configuration, maintenance, and release of point-to-point radio bearers, mobility functions, reporting, and other functions.

[0072] FIG. 6a shows a typical wireless communication system 600. The system 600 may include a distributed unit (DU) 602 communicatively connected to a radio unit (RU) 604 via one or more network switches / routers 608 using one or more Ethernet links 606. The system 600 may also include one or more synchronization masters that may be selected for each network segment within the system, and the root timing reference is called the grand master, e.g., timing grand master 610. Since the grand master can transmit synchronization information to the clocks present on that network segment, all other clocks can be directly synchronized to it when the grand master is selected. The Precision Time Protocol (PTP) (originally defined in the IEEE 1588-2002 standard) can be used to synchronize the clocks throughout the system 600. By using PTP, clock accuracy in the sub-microsecond range can be achieved. In some cases, both the DU 602 and the RU 604 may be configured to use the PTP protocol for clock synchronization purposes.

[0073] The NETCONF / YANG protocol (or application layer communication mode) may be used for the operation and / or management of network functions. NETCONF / YANG is a network management protocol developed and standardized by the Internet Engineering Task Force (IETF) under the RFC4741 and RFC6241 standards. This protocol provides a mechanism for installing, operating, and deleting the configurations of network devices.

[0074] FIG. 6b shows an alternative wireless communication system 620. In the system 620, the radio unit 622 may be communicatively connected to the distributed unit 624 via one or more switches 626 (e.g., switch 1) and 628 (e.g., switch 2). The timing grand master 630 may be co-located with the distributed unit 624.

[0075] Figure 6c shows Table 640 indicating the types of messages that can be transmitted over the front hole communication link (between DU and RU) in the transmission direction. Messages can be transmitted in the control plane (C-plane), user plane (U-plane), synchronization plane (S-plane), and management plane (M-plane). The control plane may include uplink messages and downlink messages (both from DU to RU). The user plane may also include uplink (from RU to DU) messages and downlink (from DU to RU) messages, and IQ samples can be transmitted to / from user equipment. The uplink / downlink direction does not apply to the transmission of messages in the synchronization plane and management plane. As described above, the synchronization plane includes messages carrying timing information related to the timing grand master. The management plane carries messages related to configuration (from DU to RU) and notification / measurement (from RU to DU).

[0076] If redundant links are used for recovery functions on the front haul, various problems may occur. In particular, front haul networks are extremely sensitive to latency and jitter. Wireless units typically expect C-plane messages and U-plane messages within an exact time window for each slot. The arrival times of the first and last messages in the RU and DU at specific slots and / or symbols are particularly influenced by their respective receive window parameters / designs. Therefore, the latency and / or jitter introduced by switches within the front haul link (e.g., switches 608, 626, 628 shown in FIGS. 6a to 6b) may adversely affect the functions of the RU and / or DU. In a redundant front haul network (e.g., a network having multiple front haul links as shown in FIGS. 6a to 6b), each front haul link may experience different latency and / or jitter depending on the path each link takes within the front haul link network. If multiple links are deployed between the DU and the RU (illustrated in FIGS. 6a to 6b), the same set of switches may not be used to avoid the above problems.

[0077] FIG. 7 shows a typical redundant front haul link network 700. The network 700 may include an RU 702, a DU 704, a gateway 706, a timing grand master 708, switches 710 (switch 1), 712 (switch 2). The RU 702 and the DU 704 may be communicatively connected using links 714 and 716 via the gateway 706. The links 714 and 716 may be Ethernet front haul links. Link 714 may experience different latency and / or jitter than link 716.

[0078] To adjust the timing of transmitting control plane messages and user plane messages, the one-way latency between the DU and the RU can be determined on each link based on the latency experienced on a specific front-haul link. FIG. 8 shows a typical one-way delay measurement call flow diagram 800. The process shown in FIG. 8 can be executed between two nodes, namely node 1 802 and node 2 804. Nodes 802 and 804 may be part of a base station, for example, they may be the DU and the RU respectively.

[0079] Specifically, the one-way latency can be measured from the DU to the RU (illustrated as step "I" in FIG. 8) and from the RU to the DU (illustrated as step "II" in FIG. 8). The latency from the RU to the DU can be measured by the DU using one or more eCPRI messages. As shown in FIG. 8, the latency from the DU to the RU can be measured using one or more one-way delay measurements. The delay measurement from the DU to the RU includes an ID (e.g., extended antenna carrier ID), requested data, start time t 1 , and the difference t between the start time and the measurement request transmission cv1 . The request from the DU can be received by the RU, and the RU can then transmit a response to the DU shortly thereafter, i.e., at time t 2 , which can be shortly after the receipt of the request, i.e., after t cv2 . The response from the RU can include the ID, response data, and times t 2 and t cv2 . The total delay time t d is calculated as the difference between the above times, i.e., t d =(t 2 -t cv2 )-(t 1 +t cv1 ).

[0080] The latency from the RU to the DU (step II) can be determined similarly. In this case, the delay measurement can be started as a result of a one-way delay measurement request that can be transmitted from the DU and can include the ID from the DU and the remote request data. When the request from the DU is received, the RU includes the ID, request data, start time t1 and a one-way delay measurement request that may include the start time and the difference t between the measurement request transmission cv1 can be sent to the DU. Then, the DU can respond to the RU with the ID, response data, and the times t 2 and t cv2 . Then, as the difference in the above times, i.e., t d =(t 2 -t cv2 )-(t 1 +t cv1 ), the total delay time t d can be recalculated again, where the first times (i.e., t 2 and t cv2 ) correspond to the times related to the RU, and the second times (i.e., t 1 and t cv1 ) correspond to the times related to the DU.

[0081] At the radio interface level, different antenna carriers and channel ports within the RU can be identified using the extended antenna carrier ID (eAxC ID). For example, each of the antenna ports (e.g., 4 ports) can receive a unique eAxC ID for a different channel. The eAxC ID can be a 16-bit value split into 4 fields, e.g., DU port ID, band sector ID, carrier ID, RU port ID. The bit width of each field can be configurable. Table 1 shows an overview of a typical eAxC ID. Table 1 also reveals whether each of the channel formats is delay-sensitive or not.

[0082]

Table 1

[0083] As shown in Table 1, the channel formats include PRACH (uplink random access), PDxCH (downlink physical channel), PUxCH (uplink physical channel), and sounding reference signal (SRS). For example, in the case of 32-port massive MIMO, SRS can be transmitted on all 32 antenna ports. Note that Table 1 shows a 4-port system for simplicity of explanation. Neither PRACH nor SRS is sensitive to delay. Therefore, strict boundaries of the transmission window and / or reception window do not apply to these channel formats. However, for the delay-sensitive downlink physical channel and uplink physical channel, the transmission window can typically be in the period of 1 to 2 symbols (1 symbol is 71 μsec at 15KHz SCS and 36 μsec at 30KHz SCS).

[0084] Various conventional systems provide a mechanism for associating each eAxC ID with a specific RU Ethernet port (e.g., MAC address). Therefore, the uplink channel and downlink channel each use a different fronthaul link and can pass through different paths. However, currently, there is no mechanism for dynamically associating the eAxC ID with a specific Ethernet port of the DU or RU according to the one-way latency determined / measured on that link. For example, when the DU instructs the RU to use a specific Ethernet port for the uplink channel eAxC ID, the conventional system does not provide for the DU to communicate a path switch to the RU.

[0085] III. Fronthaul Link Selection in a Wireless Communication System In some implementations, to address the above drawbacks of conventional systems, the present subject matter may be configured such that, instead of static association at initialization, a particular RU determines whether it supports dynamic association of an eAxC ID to an Ethernet port. The present subject matter may further be configured such that the RU (assuming such an ability is supported) is able to switch traffic of a particular eAxC ID to a particular Ethernet link (e.g., using a particular Ethernet port).

[0086] For example, the present subject matter may be configured to use one-way delay / latency measurements on an Ethernet link (illustrated in FIG. 8) to adjust one or more transmission windows for control and / or user plane messages according to the measured delay. The link of the physical channel to the Ethernet port within the RU may be presumptively set. For example, the RU and the DU may be configured and / or instructed to select an Ethernet link having a minimal amount of determined / measured delay for delay-sensitive channel formats (e.g., PDxCH and PUxCH). In particular, the selection of such a link for these channel formats can have the highest priority. Further, since the PRACH channel format is not delay-sensitive, the uplink PRACH IQ sample transfer can also take a path such as being usable as long as the measured delay is below a predetermined threshold tolerated for PRACH channel processing.

[0087] In addition, RU and DU can be instructed to select a specific Ethernet link based on a specific policy that can be implemented (e.g., a carrier policy). For example, the policy can be determined based on the usage status of the link and / or some other decision-making material. In this case, different priorities can be assigned to each Ethernet link through a specific configuration, and the real-time latency measured on such a link may not have the same priority (e.g., the link with the highest priority does not always have the minimum latency). The assignment of priorities based on such a policy can be due to, for example, service level agreement (SLA) reasons when the front-haul transport network is leased from a transport network carrier. In some implementations, the subject matter can be configured to algorithmically determine the priority for each of a plurality of links (for each eAxC ID) based on at least any one of the following decision-making materials (e.g., determined at the DU), namely, the priority assigned by the carrier at the initial configuration, the latency measured on each link, and / or any combination thereof.

[0088] Furthermore, in some wireless communication networks such as a multi-operator radio access network (RAN) network (MORAN), each public land mobile network (PLMN) can include a separate DU instance. In this case, each such DU instance can function as a PTP grandmaster, and each RU that functions as a telecommunication time slave clock (T-TSC) can determine which PTP grandmaster can be used for synchronization purposes. If any one of the PLMN instances is terminated (e.g., stopped) at the DU, terminating the PLMN instance at the DU (where the RU is synchronized) does not require stopping the S-plane traffic / clock distribution from that DU host, so the RU may need to be configured not to use the link connected to the DU instance of the PLMN that is terminated for S-plane traffic.

[0089] In some implementations, the subject matter can be configured to identify a RU that supports dynamic association of an eAxC ID to an Ethernet port, instead of statically associating the eAxC ID at initialization. Further, the subject matter can be configured to notify a RU (that supports this ability) to switch a particular eAxC ID traffic to a particular Ethernet link. Further, the RU and DU can be configured to use one or more front haul links according to a mapping of eAxC IDs to the links that can be provided to the RU / DU.

[0090] FIG. 9a shows an exemplary system 900 for determining the ability of a RU that supports dynamic association of an eAxC ID to one or more Ethernet ports, according to some implementations of the subject matter. FIG. 9b shows an exemplary process 910 for determining the ability of a RU that can be performed by system 900, according to some implementations of the subject matter.

[0091] As shown in FIG. 9a, system 900 can include a DU 902 and a RU 904. The DU 902 can be configured to send a request to the RU 904 at 912 to determine the ability of the RU, as shown in FIG. 9b. In particular, the request can be sent during initialization of the RU, whereby the RU 904 can communicate its ability with a management plane controller (e.g., DU 902 or EMS). This communication can be performed according to NETCONF capabilities communication procedures. The RU 904 can respond to the DU 902 by generating and sending an ability response message to the DU 902 at 914, as shown in FIG. 9b. The RU 904 can generate its message in a boolean type format and / or any other desirable format. For example, the following procedure can be used to determine the ability of the RU. leaf dynamic-eaxcid-eth-port-linking{ description "Indicates that the radio unit supports dynamic linking of the eAxCId to the front haul Ethernet port on which the control plane command for the eAxCId is received"; type Boolean; }

[0092] Figure 10 shows a typical process 1000 in which a DU transmits an Ethernet link selected for control / user (C / U) plane traffic corresponding to a specific eAxC ID according to some implementations of the present subject matter. Process 1000 may be executed by the system 900 shown in FIG. 9. At 1002, the DU 902 may be configured to receive and / or obtain one-way delay measurement information from the RU to the DU (as described above with respect to FIG. 8) for each Ethernet link associated with each eAxC ID (e.g., each different eAxC ID).

[0093] At 1004, the DU 902 can measure the one-way delay from the DU to the RU (as described above with respect to FIG. 8). At 1006, the DU may also be provided with or receive an indication as to which specific channel Ethernet link is delay-sensitive (along with the corresponding eAxC ID). At 1008, for each eAxC ID, the DU can prioritize (and / or rank) the links in the uplink and / or downlink directions. The links can be prioritized using at least any one of the following parameters, namely, the delay sensitivity requirements of a specific radio channel (e.g., using the eAxC ID), the one-way measured DU-RU delay (e.g., on the downlink), the one-way determined RU-DU delay (e.g., on the uplink), a link prioritization policy that can be configured by the mobile operator (e.g., this can be optional), and any combination thereof. Table 2 shows a typical ranking of the Ethernet links (using the eAxC ID).

[0094]

Table 2

[0095] As shown in Table 2, 16 antenna eAxC IDs can be divided among PRACH (e.g., eAxC IDs 1 - 4), PDxCH (e.g., eAxC IDs 5 - 8), PUxCH (e.g., eAxC IDs 9 - 12), and SRS (e.g., eAxC IDs 13 - 16). Each can have the use of Ethernet port 0 or 1 (e.g., Eth0 and Eth1). As can be understood, there can be multiple ports, antennas, etc., and Table 2 is provided here only for illustrative, non - limiting, and exemplary purposes. As shown in Table 2, a delay weight factor (e.g., 0.1, 0.8, 0.3, etc.) and a corresponding delay link priority (e.g., 1, 2, etc.) can be assigned for each link. The highest priority can be assigned to the Ethernet port where the minimum delay is measured. The system can use a scale from 1 to N, where N can be the maximum number of available Ethernet ports (Table 2 shows only two for illustrative purposes only). Further, when a policy is implemented, a policy weight factor (e.g., 0.9, 0.2, 0.7) and a corresponding policy priority (e.g., 1, 2) can also be assigned for each link. The sum of the weight factors can be equal to 1, and a rank is determined using a weighted priority equation that uses the above - mentioned delay weight factor and policy weight factor.

[0096] In some implementations, the weight and / or priority of each link can be assigned based on one or more network policies and / or configurations. These can be specific to a deployment. Based on a particular deployment, a network operator can be informed which link can have a higher weight. For example, assuming that one of two links is a dark fiber link that can provide a consistent guarantee for bandwidth and the other link is a light fiber link, an operator using a particular configuration can assign a higher weight to the dark fiber link because of its larger bandwidth and / or deterministic latency.

[0097] As shown in Table 2, the higher the priority value of a particular link, the more likely it means that the link will be handled with a higher priority during communication. Using Table 2, for each group of eAXc IDs, for each Ethernet port, DU902 can determine the weighted priority and rank the Ethernet ports using the calculated weighted priority. DU902 can assign a higher rank to a link with a weighted priority having a higher value (i.e., the lower the numerical value in the rank column, the higher the rank), and can select the Ethernet link (connected to the Ethernet port) to be used for that particular eAxC ID.

[0098] DU902, which has identified the preferred link and data transmission direction (e.g., uplink / downlink) for each eAxC ID, as shown in FIG. 10, can use that link at 1010 for transmitting the control plane and / or user plane messages of that eAxC ID. RU904 can receive control plane and / or user plane messages from DU902 for each eAxC ID on any link and / or port. When RU904 receives control plane message traffic of a particular eAxC ID on a particular Ethernet port, it can also be expected to receive downlink user plane traffic of that eAxC ID on the same Ethernet port. Similarly, RU904 can switch the uplink user plane traffic of that eAxC ID to the determined Ethernet port (i.e., the Ethernet port on which the DU transmitted the control plane message).

[0099] In some implementations, the subject matter may be configured to be implemented in a system 1100, as shown in FIG. 11. The system 1100 may include any one or more of a processor 1110, a memory 1120, a storage device 1130, and an input / output device 1140. Each of the components 1110, 1120, 1130, and 1140 may be interconnected using a system bus 1150. The processor 1110 may be configured to process instructions executed within the system 600. In some implementations, the processor 1110 may be a single-threaded processor. In alternative implementations, the processor 1110 may be a multi-threaded processor. The processor 1110 may further be configured to process instructions stored in the memory 1120 or the storage device 1130, which may include receiving or transmitting information through the input / output device 1140. The memory 1120 may store information within the system 1100. In some implementations, the memory 1120 may be a computer-readable medium. In alternative implementations, the memory 1120 may be a volatile memory unit. In still some implementations, the memory 1120 may be a non-volatile memory unit. The storage device 1130 may provide large-capacity storage for the system 1100. In some implementations, the storage device 1130 may be a computer-readable medium. In alternative implementations, the storage device 1130 may be a floppy disk device, a hard disk device, an optical disk device, a tape device, a non-volatile solid-state memory, or any other type of storage device. The input / output device 1140 may be configured to provide input / output operations for the system 1100. In some implementations, the input / output device 1140 may include a keyboard and / or a pointing device. In alternative implementations, the input / output device 1140 may include a display unit for displaying a graphical user interface.

[0100] FIG. 12 shows an exemplary method 1200, according to some implementations of the subject matter. The process 1200 may be executed by the system 900 shown in FIG. 9.

[0101] At 1202, one or more link delays may be determined. The link delay may be associated with one or more of the plurality of communication links that communicatively connect a first communication device (e.g., a distributed unit (DU)) and a second communication device (e.g., a radio interface unit (RU)). At 1204, for the purpose of transmitting one or more data packets, the determined link delay may be used to determine the communication link transmission priority of the communication links. A list of prioritized communication links may be generated (e.g., as shown in Table 2 above).

[0102] At 1206, for the transmission of data packets between the first communication device and the second communication device, at least one communication link may be selected from the list of prioritized communication links. At 1208, using the selected communication link, data packets may be transmitted between the first communication device and the second communication device.

[0103] In some implementations, the subject matter may include any one or more of the following optional features. Link delay At least any one of determining, determining the communication link transmission priority, selecting, and transmitting may be performed by a base station. The base station may include at least any one of the following communication components, namely, a radio interface unit and a distributed unit. The distributed unit may be configured to cooperate with the radio interface unit for the transmission of data packets.

[0104] In some implementations, the first communication device may include a distributed unit, and the second communication device may include a radio interface unit. The link delay may include at least one first link delay associated with the transmission of a data packet from the distributed unit to the radio interface unit, at least one second link delay associated with the transmission of a data packet from the radio interface unit to the distributed unit, and at least any one of any combination thereof. The downlink path delay of each available link can be measured by the distributed unit. The uplink path delay of each available link can be measured by the radio interface unit. One or more timestamps associated with the uplink path may be provided to the distributed unit to determine the uplink path delay as the measured uplink path. In some implementations, the method may include determining the delay sensitivity associated with the transmission of a data packet on a communication link. The delay sensitivity can be determined based on at least any one of the downlink path and uplink path delays that do not exceed at least one predetermined delay threshold. The communication link transmission priority can be determined using at least any one of the downlink path and uplink path delays and the determined delay sensitivity.

[0105] In some implementations, determining the communication link transmission priority may include assigning one or more weighting factors to at least any one of the downlink path and uplink path delays (e.g., as shown in Table 2) and the determined delay sensitivity. Generating a list may include generating a weighted list of prioritized communication links using the assigned weighting factors.

[0106] In some implementations, the method may include receiving, by the second communication device, a control plane message from the first communication device on a selected communication link and transmitting, by the second communication device, a user plane message to the first communication device on the selected communication link.

[0107] In some implementations, the method may include receiving, by a second communication device, a control plane message from a first communication device on a selected communication link, and switching, by the second communication device, to a communication link selected from among at least another communication link of a plurality of communication links for transmission of a user plane message from the second communication device to the first communication device.

[0108] In some implementations, each link of the plurality of communication links may be associated with an Ethernet port of at least one of the first communication device and the second communication device and may be identified by an extended antenna carrier identifier.

[0109] The systems and methods disclosed herein may be embodied in various forms including, for example, a data processor such as a computer including a database, digital electronic circuitry, firmware, software, or combinations thereof. Further, the above features as well as other aspects and principles of the disclosed implementations may be implemented in various environments. Such environments and related applications may be specially constructed to perform various processes and operations in accordance with the disclosed implementations, or they may include a general purpose computer or computing platform selectively activated or reconfigured by code to provide the required functionality. The processes disclosed herein are not inherently related to a particular computer, network, architecture, environment, or other apparatus, and may be implemented by a suitable combination of hardware, software, and / or firmware. For example, various general purpose machines may be used with programs written in accordance with the teachings of the disclosed implementations, or it may be more convenient to construct a dedicated device or system for performing the required methods and techniques.

[0110] The systems and methods disclosed herein may be implemented as a computer program product, i.e., an information carrier tangibly embodied in a machine-readable storage device or a propagated signal, executed or controlled in operation by a data processing apparatus, e.g., a programmable processor, a computer, or multiple computers. The computer program may be written in any form of programming language, including a compiled or interpreted language, and may be deployed in any form, as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. The computer program may be deployed to be executed on one computer or on multiple computers at one site or on multiple computers distributed at multiple sites and interconnected by a communication network.

[0111] As used herein, the term "user" may refer to any entity, including a person or a computer.

[0112] Ordinal numbers such as first, second, etc. may in some cases be related to order, but the ordinal numbers used herein do not necessarily imply order. For example, an ordinal number may simply be used to distinguish one item from another. For example, to distinguish a first event from a second event, and does not necessarily imply a time series order or a fixed reference system (thus, the first event in one paragraph of the description may be different from the first event in another paragraph of the description).

[0113] The foregoing description is intended to illustrate, not to limit, the scope of the invention as defined by the appended claims. Other implementations are within the scope of the following claims.

[0114] These computer programs, sometimes called programs, software, software applications, applications, components, or code, include machine instructions for a programmable processor and can be implemented in high-level procedural and / or object-oriented programming languages, and / or in assembly / machine language. As used herein, the term "machine-readable medium" refers to any computer program product, apparatus, and / or device used to provide machine instructions and / or data to a programmable processor, such as magnetic disks, optical disks, memory, and programmable logic devices (PLDs), and includes a machine-readable medium that receives machine instructions as a machine-readable signal. The term "machine-readable signal" refers to any signal used to provide machine instructions and / or data to a programmable processor. A machine-readable medium can temporarily store such machine instructions, for example, in a non-transitory solid-state memory or a magnetic hard drive or any equivalent storage medium. Alternatively, or in addition, a machine-readable medium can temporarily store such machine instructions, for example, in a processor cache or other random access memory associated with one or more physical processor cores.

[0115] To provide for interaction with a user, the subject matter described herein can be implemented on a computer having, for example, a display device such as a cathode ray tube (CRT) or a liquid crystal display (LCD) monitor for displaying information to the user, and a keyboard and a pointing device such as a mouse or a trackball by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well. For example, feedback provided to the user can be any form of sensory feedback, such as, but not limited to, visual feedback, auditory feedback, or tactile feedback, and input received from the user can be in any form including, but not limited to, acoustic, speech, or tactile input.

[0116] The subject matter described in this specification can be implemented in a computing system that includes back-end components, such as one or more data servers, or middleware components, such as one or more application servers, or front-end components, such as one or more client computers having a graphical user interface or a web browser through which a user can interact with an implementation of the subject matter described in this specification, or in any combination of such back-end, middleware, or front-end components. The components of the system can be interconnected by digital data communication in any form or medium, such as, for example, a communication network. Examples of communication networks include, but are not limited to, local area networks ("LANs"), wide area networks ("WANs"), and the Internet.

[0117] A computing system can include clients and servers. Clients and servers are generally, but not exclusively, located remotely from each other and typically interact with each other through a communication network. The relationship between a client and a server arises by computer programs running on respective computers and having a client-server relationship to each other.

[0118] The implementations described in the foregoing description do not represent all implementations that fall within the subject matter described in this specification. Instead, they are merely some examples that conform to aspects related to the described subject matter. Although some variations have been described in detail above, other modifications or additions are possible. In particular, additional features and / or variations may be provided in addition to those described in this specification. For example, the implementations described above may be directed to various combinations and sub - combinations of the disclosed features, and / or combinations and sub - combinations of some additional features disclosed above. Additionally, the logical flows shown in the accompanying drawings and / or described in this specification do not necessarily require the particular order or sequence shown to achieve the desired result. Other implementations may be within the scope of the following claims.

Claims

Claim 1 Determining one or more link delays associated with any one or more of a plurality of communication links that communicably connect a first communication device and a second communication device; Using the determined one or more link delays to determine the communication link transmission priorities of the one or more communication links so as to assign the highest communication link transmission priority to the communication link having the minimum link delay for transmission of one or more data packets, and generating a list of the one or more prioritized communication links; Selecting at least one communication link having the highest communication link transmission priority among the one or more prioritized communication links for transmission of one or more data packets between the first communication device and the second communication device; Transmitting the one or more data packets between the first communication device and the second communication device using the selected at least one communication link, and At least any one of the determining the link delay, the determining the communication link transmission priority, the selecting, and the transmitting is performed by a base station, The base station has at least any one of the following communication components, namely, one or more radio interface units and one or more distributed units, The first communication device has a distributed unit, and the second communication device has a radio interface unit, The one or more link delays have at least any one of at least one first link delay associated with transmission of one or more data packets from the distributed unit to the radio interface unit, at least one second link delay associated with transmission of one or more data packets from the radio interface unit to the distributed unit, and any combination thereof, The downlink path delay of each available link is measured by the distributed unit, The uplink path delay of each available link is measured by the radio interface unit, and one or more timestamps associated with the uplink path are provided to the distributed unit to determine the uplink path delay as the measured uplink path, A method implemented by a computer. Claim 2 The method according to claim 1, wherein the one or more distributed units are configured to cooperate with the one or more wireless interface units for transmission of the one or more data packets.

3. The method according to claim 1, further comprising determining a delay sensitivity associated with transmission of one or more data packets on the one or more communication links, wherein the delay sensitivity is determined based on at least one of the downlink path and uplink path delays that do not exceed at least one predetermined delay threshold.

4. The method according to claim 3, wherein the communication link transmission priority is determined using at least one of the downlink path and uplink path delays and the determined delay sensitivity.

5. Determining the communication link transmission priority further comprises assigning one or more weighting factors to each of the delays of the downlink path and uplink path and the determined delay sensitivity, and generating comprises generating a weighted list of one or more communication links with priorities assigned using the assigned weighting factors. The method according to claim 4.

6. Receiving, by the second communication device, a control plane message from the first communication device on the at least one selected communication link; The method according to claim 1, further comprising transmitting, by the second communication device, a user plane message to the first communication device on the at least one selected communication link.

7. Determining one or more link delays associated with any one or more of a plurality of communication links communicatively connecting a first communication device and a second communication device; Using the determined one or more link delays to determine the communication link transmission priorities of the one or more communication links so as to assign the highest communication link transmission priority to the communication link having the minimum link delay for transmission of one or more data packets, and generating a list of the one or more prioritized communication links; Selecting at least one communication link having the highest communication link transmission priority among the one or more prioritized communication links for transmission of one or more data packets between the first communication device and the second communication device; Transmitting the one or more data packets between the first communication device and the second communication device using the at least one selected communication link; Receiving, by the second communication device, a control plane message from the first communication device on the at least one selected communication link; Further comprising switching, by the second communication device, from the at least one selected communication link to at least another communication link among the plurality of communication links for transmitting a user plane message from the second communication device to the first communication device, a computer-implemented method.

8. Determining one or more link delays associated with any one or more of a plurality of communication links communicatively connecting a first communication device and a second communication device; Using the determined one or more link delays to determine a communication link transmission priority of the one or more communication links so as to assign the highest communication link transmission priority to the communication link having the minimum link delay for transmitting the one or more data packets, and generating a list of the one or more prioritized communication links; Selecting at least one communication link having the highest communication link transmission priority among the one or more prioritized communication links for transmitting the one or more data packets between the first communication device and the second communication device; Transmitting the one or more data packets between the first communication device and the second communication device using the at least one selected communication link; Each link of the plurality of communication links is associated with at least one of the Ethernet ports of the first communication device and the second communication device and is identified by an extended antenna carrier identifier, a computer-implemented method.

9. A system having at least one programmable processor and a non-transitory machine-readable medium storing instructions, which, when executed by the at least one programmable processor, cause the at least one programmable processor to Determine one or more link delays associated with any one or more of a plurality of communication links communicatively connecting a first communication device and a second communication device; ​ Determine the communication link transmission priorities of the one or more communication links such that, using the determined one or more link delays, the highest communication link transmission priority is assigned to the communication link with the minimum link delay for the transmission of one or more data packets; and generate a list of the one or more prioritized communication links; For the transmission of one or more data packets between the first communication device and the second communication device, select at least one communication link having the highest communication link transmission priority among the one or more prioritized communication links; Cause an operation to be performed that includes transmitting the one or more data packets between the first communication device and the second communication device using the selected at least one communication link; At least any one of the determining of the link delay, the determining of the communication link transmission priority, the selecting, and the transmitting is performed by a base station; The base station has at least any one of the following communication components, namely, one or more radio interface units and one or more distributed units; The first communication device has a distributed unit, and the second communication device has a radio interface unit; The one or more link delays include at least any one of at least one first link delay related to the transmission of one or more data packets from the distributed unit to the radio interface unit, at least one second link delay related to the transmission of one or more data packets from the radio interface unit to the distributed unit, and any combination thereof; The downlink path delay of each available link is measured by the distributed unit; The uplink path delay of each available link is measured by the radio interface unit, and one or more timestamps related to the uplink path are provided to the distributed unit to determine the uplink path delay as the measured uplink path; System.

10. At least one programmable processor; A system having a non-transitory machine-readable medium storing instructions which, when executed by the at least one programmable processor, cause the at least one programmable processor to determine one or more link delays associated with any one or more of a plurality of communication links communicatively connecting a first communication device and a second communication device; determine the communication link transmission priorities of the one or more communication links to assign the highest communication link transmission priority to the communication link having the minimum link delay for transmission of one or more data packets using the determined one or more link delays, and generate a list of the one or more prioritized communication links; select at least one communication link having the highest communication link transmission priority among the one or more prioritized communication links for transmission of one or more data packets between the first communication device and the second communication device; cause an operation to be performed that includes transmitting the one or more data packets between the first communication device and the second communication device using the selected at least one communication link; wherein each link of the plurality of communication links is associated with at least one Ethernet port of at least one of the first communication device and the second communication device and is identified by an extended antenna carrier identifier; A system. **Claim 11** A computer program which, when executed by at least one programmable processor, causes the at least one programmable processor to determine one or more link delays associated with any one or more of a plurality of communication links communicatively connecting a first communication device and a second communication device; determine the communication link transmission priorities of the one or more communication links to assign the highest communication link transmission priority to the communication link having the minimum link delay for transmission of one or more data packets using the determined one or more link delays, and generate a list of the one or more prioritized communication links; For transmitting one or more data packets between the first communication device and the second communication device, selecting at least one communication link having the highest communication link transmission priority among the one or more prioritized communication links, and using the selected at least one communication link to transmit the one or more data packets between the first communication device and the second communication device, and executing an operation having, At least any one of the determining the link delay, the determining the communication link transmission priority, the selecting, and the transmitting is executed by a base station, The base station has at least any one of the following communication components, that is, one or more radio interface units and one or more distributed units, The first communication device has a distributed unit, and the second communication device has a radio interface unit, The one or more link delays include at least any one of at least one first link delay related to transmitting one or more data packets from the distributed unit to the radio interface unit, at least one second link delay related to transmitting one or more data packets from the radio interface unit to the distributed unit, and any combination thereof, The downlink path delay of each available link is measured by the distributed unit, The uplink path delay of each available link is measured by the radio interface unit, and one or more timestamps related to the uplink path are provided to the distributed unit to determine the uplink path delay as the measured uplink path, A computer program. **Claim 12**: A computer program which, when executed by at least one programmable processor, causes the at least one programmable processor to, Determine one or more link delays related to any one or more of a plurality of communication links that communicably connect a first communication device and a second communication device, Determine the communication link transmission priorities of the one or more communication links to assign the highest communication link transmission priority to the communication link with the minimum link delay for the transmission of one or more data packets using the determined one or more link delays; and generate a list of the one or more prioritized communication links; For the transmission of one or more data packets between the first communication device and the second communication device, select at least one communication link having the highest communication link transmission priority among the one or more prioritized communication links; and transmit the one or more data packets between the first communication device and the second communication device using the selected at least one communication link, wherein each link of the plurality of communication links is associated with at least one of the Ethernet ports of the first communication device and the second communication device and is identified by an extended antenna carrier identifier; A computer program.

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