EP4662898A1

EP4662898A1 - Explicit congestion notification marking

Info

Publication number: EP4662898A1
Application number: EP23884285.0A
Authority: EP
Inventors: Mingzeng Dai; Haiyan Luo; Xiaoying Xu
Original assignee: Lenovo Beijing Ltd
Current assignee: Lenovo Beijing Ltd
Priority date: 2023-07-07
Filing date: 2023-07-07
Publication date: 2025-12-17
Also published as: CN120883662A; WO2024093346A1; GB2642017A

Abstract

Embodiments of the present disclosure relate to explicit congestion notification (ECN) marking. In some embodiments, a first RAN node receives, from a second RAN node, information associated with a congestion status at the second RAN node. Moreover, the first RAN node performs, based on the information, ECN marking for at least one quality of service (QoS) flow associated with a data radio bearer (DRB), where the DRB is terminated at the first RAN node. In this way, it is possible to improve the flexibility of ECN marking and thus improve communication efficiency.

Description

EXPLICIT CONGESTION NOTIFICATION MARKING

TECHNICAL FIELD

The present disclosure relates to wireless communications, and more specifically to explicit congestion notification (ECN) marking.

BACKGROUND

A wireless communications system may include one or multiple network communication devices, such as base stations, which may be otherwise known as an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. Each network communication devices, such as a base station may support wireless communications for one or multiple user communication devices, which may be otherwise known as user equipment (UE) , or other suitable terminology. The wireless communications system may support wireless communications with one or multiple user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) . Additionally, the wireless communications system may support wireless communications across various radio access technologies including third generation (3G) radio access technology, fourth generation (4G) radio access technology, fifth generation (5G) radio access technology, among other suitable radio access technologies beyond 5G (e.g., sixth generation (6G) ) .
With the development of communication technologies, several technologies have been proposed. For example, ECN marking for low latency, low loss and scalable throughput (L4S) has been introduced for congestion-level information exposure. It exposes congestion information by marking ECN bits in the internet protocol (IP) header of the user IP packets between the UE and the application server to trigger application layer rate adaptation. However, enhancements on the ECN marking procedure are still needed.

SUMMARY

The present disclosure relates to network nodes, methods, and processors that support ECN marking. With the apparatuses and methods, it is possible to improve the flexibility of ECN marking and thus improve communication efficiency.
In a first aspect, there is provided a first RAN node. The first RAN node comprises at least one memory; and at least one processor coupled with the at least one memory and configured to cause the first RAN node to: receive, from a second RAN node, information associated with a congestion status at the second RAN node; and perform, based on the information, explicit congestion notification (ECN) marking for at least one quality of service (QoS) flow associated with a data radio bearer (DRB) , wherein the DRB is terminated at the first RAN node.
In a second aspect, there is provided a second RAN node. The second RAN node comprises at least one memory; and at least one processor coupled with the at least one memory and configured to cause the RAN node to: determine information associated with a congestion status at the second RAN node; and transmit, to a first RAN node, the information for explicit congestion notification (ECN) marking for at least one quality of service (QoS) flow associated with a data radio bearer (DRB) , wherein the DRB is terminated at the first RAN node.
In a third aspect, there is provided a method performed by the first RAN node. The method comprises: receiving, from a second RAN node, information associated with a congestion status at the second RAN node; and performing, based on the information, explicit congestion notification (ECN) marking for at least one quality of service (QoS) flow associated with a data radio bearer (DRB) , wherein the DRB is terminated at the first RAN node.
In a fourth aspect, there is provided a method performed by the second RAN node. The method comprises: determining information associated with a congestion status at the second RAN node; and transmitting, to a first RAN node, the information for explicit congestion notification (ECN) marking for at least one quality of service (QoS) flow associated with a data radio bearer (DRB) , wherein the DRB is terminated at the first RAN node.
In a fifth aspect, there is provided a processor for wireless communication. The processor comprises at least one controller coupled with at least one memory and configured to cause the processor to: receive, from a second RAN node, information associated with a congestion status at the second RAN node; and perform, based on the information, explicit congestion notification (ECN) marking for at least one quality of service (QoS) flow associated with a data radio bearer (DRB) , wherein the DRB is terminated at the first RAN node.
In a sixth aspect, there is provided a processor for wireless communication. The processor comprises at least one controller coupled with at least one memory and configured to cause the processor to: determine information associated with a congestion status at the second RAN node; and transmit, to a first RAN node, the information for explicit congestion notification (ECN) marking for at least one quality of service (QoS) flow associated with a data radio bearer (DRB) , wherein the DRB is terminated at the first RAN node.
In some implementations of the method and the first RAN node described herein, the first RAN node further transmits, to the second RAN node, a request for the information. In some implementations of the method and the first RAN node described herein, the request comprises at least one of: a periodicity for the second RAN node to transmit the information; or an event to trigger the second RAN node to transmit the information. In some implementations of the method and the first RAN node described herein, the event comprises at least one of: a congestion level associated with the second RAN node being above a congestion level threshold; or a congestion ratio associated with the second RAN node being above a congestion ratio threshold.
In some implementations of the method and the first RAN node described herein, the information comprises at least one of: an indication to perform ECN marking for partial or all packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow; a suggested ratio of packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow to be ECN marked; or a congestion level associated with the second RAN node. In some implementations of the method and the first RAN node described herein, the information is comprised in a SECONDARY NODE (S-NODE) MODIFICATION REQUIRED message.
In some implementations of the method and the first RAN node described herein, the information comprises at least one of: an indication indicating whether there is congestion experienced at the second RAN node; a suggested ratio of packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow to be ECN marked; or a congestion level associated with the second RAN node. In some implementations of the method and the first RAN node described herein, the information is comprised in a general packet radio service tunneling protocol user plane (GTP-U) extension header. In some implementations of the method and the first RAN node described herein, the information is comprised in a Downlink Data Delivery Status frame.
In some implementations of the method and the first RAN node described herein, the first RAN node performs the ECN marking by: performing the ECN marking based on a congestion status at the first RAN node and the information.
In some implementations of the method and the first RAN node described herein, the first RAN node further transmits, to the second RAN node, a congestion enable indication that the ECN marking for the DRB or the at least one QoS flow is required. In some implementations of the method and the first RAN node described herein, the congestion enable indication implicitly indicates a request for the information. In some implementations of the method and the first RAN node described herein, the first RAN node comprises a master RAN node and the second RAN node comprises a secondary RAN node, the master RAN node and the secondary RAN node being served as dual connectivity for user equipment (UE) , and the DRB is master RAN node terminated SCG bearer or master RAN node terminated split bearer.
In some implementations of the method and the first RAN node described herein, the first RAN node further receives, from the second RAN node, a congestion enable indication that the ECN marking for the DRB or the at least one QoS flow is required. In some implementations of the method and the first RAN node described herein, the first RAN node comprises a secondary RAN node and the second RAN node comprises a master RAN node, the master RAN node and the secondary RAN node being served as dual connectivity for user equipment (UE) and the DRB is secondary RAN node terminated MCG bearer or secondary RAN node terminated split bearer.
In some implementations of the method and the first RAN node described herein, the congestion enable indication is comprised in an S-NODE ADDITION REQUEST message or an S-NODE MODIFICATION REQUEST message.
In some implementations of the method and the first RAN node described herein, the first RAN node comprises a centralized unit (CU) of a base station (BS) , and the second RAN node comprises a distributed unit (DU) of the BS. In some implementations of the method and the first RAN node described herein, the CU comprises a control plane (CP) and a user plane (UP) , and the information is received by the CP of the CU from the DU, and the information is forwarded by the CP of the CU to the UP of the CU, and the ECN marking is performed by the UP of the CU.
In some implementations of the method and the second RAN node described herein, the second RAN node further receives, from the first RAN node, a request for the information. In some implementations of the method and the second RAN node described herein, the request comprises at least one of: a periodicity for the second RAN node to transmit the information; or an event to trigger the second RAN node to transmit the information. In some implementations of the method and the second RAN node described herein, the event comprises at least one of: a congestion level associated with the second RAN node being above a congestion level threshold; or a congestion ratio associated with the second RAN node being above a congestion ratio threshold.
In some implementations of the method and the second RAN node described herein, the information comprises at least one of: an indication to perform ECN marking for partial or all packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow; a suggested ratio of packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow to be ECN marked; or a congestion level associated with the second RAN node. In some implementations of the method and the second RAN node described herein, the information is comprised in a SECONDARY NODE (S-NODE) MODIFICATION REQUIRED message.
In some implementations of the method and the second RAN node described herein, the information comprises at least one of: an indication indicating whether there is congestion experienced at the second RAN node; a suggested ratio of packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow to be ECN marked; or a congestion level associated with the second RAN node. In some implementations of the method and the second RAN node described herein, the information is comprised in a general packet radio service tunneling protocol user plane (GTP-U) extension header. In some implementations of the method and the second RAN node described herein, the information is comprised in a Downlink Data Delivery Status frame.
In some implementations of the method and the second RAN node described herein, the second RAN node further receives, from the first RAN node, a congestion enable indication that the ECN marking for the DRB or the at least one QoS flow is required. In some implementations of the method and the second RAN node described herein, the congestion enable indication implicitly indicates a request for the information. In some implementations of the method and the second RAN node described herein, the first RAN node comprises a master RAN node and the second RAN node comprises a secondary RAN node, the master RAN node and the secondary RAN node being served as dual connectivity for user equipment (UE) , and the DRB is master RAN node terminated SCG bearer or master RAN node terminated split bearer.
In some implementations of the method and the second RAN node described herein, the second RAN node further transmits, to the first RAN node, an indication that the ECN marking for the DRB or the at least one QoS flow is required. In some implementations of the method and the second RAN node described herein, the first RAN node comprises a secondary RAN node and the second RAN node comprises a master RAN node, the master RAN node and the secondary RAN node being served as dual connectivity for user equipment (UE) and the DRB is secondary RAN node terminated MCG bearer or secondary RAN node terminated split bearer.
In some implementations of the method and the second RAN node described herein, the indication is comprised in an S-NODE ADDITION REQUEST message or an S-NODE MODIFICATION REQUEST message.
In some implementations of the method and the second RAN node described herein, the first RAN node comprises a centralized unit (CU) of a base station (BS) , and the second RAN node comprises a distributed unit (DU) of the BS. In some implementations of the method and the second RAN node described herein, the CU comprises a control plane (CP) and a user plane (UP) , and the information is received by the CP of the CU from the DU, and the information is forwarded by the CP of the CU to the UP of the CU, and the ECN marking is performed by the UP of the CU.
It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, 1B, 1C, and 1D illustrate an example of a wireless communications system that supports ECN marking in accordance with aspects of the present disclosure, respectively;
FIG. 1E illustrates an example diagram of ECN codepoints associated with aspects of the present disclosure;
FIG. 1F illustrates an example overview procedure of ECN marking associated with aspects of the present disclosure;
FIGS. 1G and 1H illustrate example radio protocol architectures associated with aspects of the present disclosure;
FIGS. 1I and 1J illustrate example network side protocol termination options associated with aspects of the present disclosure;
FIG. 2 illustrates an example signaling chart of a communication process that supports ECN marking in DC in accordance with aspects of the present disclosure;
FIG. 3 illustrates an example communication process that supports ECN marking in DC in accordance with aspects of the present disclosure;
FIG. 4 illustrates a schematic diagram of ECN marking in accordance with aspects of the present disclosure;
FIG. 5 illustrates another example communication process that supports ECN marking in DC in accordance with aspects of the present disclosure;
FIG. 6 illustrates an example signaling chart of a communication process that supports ECN marking during handover in accordance with aspects of the present disclosure;
FIG. 7 illustrates another example signaling chart of a communication process that supports ECN marking during handover in accordance with aspects of the present disclosure.
FIG. 8 illustrates an example of a device that supports ECN marking in accordance with aspects of the present disclosure, respectively;
FIG. 9 illustrates an example of a processor that supports ECN marking in accordance with aspects of the present disclosure, respectively; and
FIGS. 10 and 11 illustrate flowcharts of methods that support ECN marking in accordance with aspects of the present disclosure.
Throughout the drawings, the same or similar reference numerals represent the same or similar elements.

DETAILED DESCRIPTION

Principles of the present disclosure will now be described with reference to some embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.
In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.
References in the present disclosure to “one embodiment, ” “an example embodiment, ” “an embodiment, ” “some embodiments, ” and the like indicate that the embodiment (s) described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment (s) . Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
It shall be understood that although the terms “first” and “second” or the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element could also be termed as a second element, and similarly, a second element could also be termed as a first element, without departing from the scope of embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms. In some examples, values, procedures, or apparatuses are referred to as “best, ” “lowest, ” “highest, ” “minimum, ” “maximum, ” or the like. It will be appreciated that such descriptions are intended to indicate that a selection among many used functional alternatives can be made, and such selections need not be better, smaller, higher, or otherwise preferable to other selections.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments. As used herein, the singular forms “a, ” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises, ” “comprising, ” “has, ” “having, ” “includes” and/or “including, ” when used herein, specify the presence of stated features, elements, components and/or the like, but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof. For example, the term “includes” and its variants are to be read as open terms that mean “includes, but is not limited to. ” The term “based on” is to be read as “based at least in part on. ” The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ” The term “another embodiment” is to be read as “at least one other embodiment. ” The use of an expression such as “A and/or B” can mean either “only A” or “only B” or “both A and B. ” Other definitions, explicit and implicit, may be included below.
As mentioned above, ECN marking for low latency, low loss and scalable throughput (L4S) has been introduced for congestion-level information exposure. For example, the following text box describes the support of ECN marking for L4S as specified in technical specification (TS) 23.501.
In the scenario where a master node (MN) and a secondary node (SN) are served as dual connectivity (DC) for user equipment (UE) , for ECN marking in the next-generation radio access network (NG-RAN) , there are some bearers carried by two legs. For example, in New Radio (NR) -DC, the MN is the master NG-RAN node and the SN is the secondary NG-RAN node. For example, for the split bearer, the bearer may be carried by the master cell group (MCG) and the secondary cell group (SCG) from the MN and the SN respectively, where one of the MN and SN is packet data convergence protocol (PDCP) terminated node and the other one is a peer node. Since the ECN bits are marked in the IP header of the user IP packets, the peer node is not able to mark ECN bits as the packets have been encrypted by the PDCP layer as a PDCP protocol data unit (PDU) . For example, for MN terminated split bearer, the SN cannot perform ECN marking in the IP header of the user IP packets since the PDCP PDU is transmitted between the MN and UE.
Moreover, for user plane function (UPF) based ECN marking, the peer node does not have an NG-user plane (NG-U) connection to the UPF, thus the peer node is unable to provide congestion information (for example, a percentage of packets for ECN marking for L4S) of a QoS Flow to the UPF by a general packet radio service tunneling protocol user plane (GTP-U) header directly. For example, for MN terminated split bearer, the SN cannot provide the congestion information to the UPF directly since the user data is terminated at the MN.
In addition, in the handover scenario where a handover occurs from a source gNB to the target gNB, data forwarding may be performed to avoid data loss. For example, the source gNB may forward downlink (DL) fresh data (either a PDCP SDU or service data adaptation protocol (SDAP) service data unit (SDU) ) to the target gNB. The source gNB may also forward all downlink PDCP SDUs with their sequence number corresponding to PDCP SDUs which have not been acknowledged by the UE. The source gNB may also forward the uplink PDCP SDUs with their sequence number corresponding to PDCP PDUs received out of sequence. For these forwarded data, the ECN bits may have been marked due to congestion at the source gNB. However, there may be not congested at the target gNB, in which case ECN bits of these data should not be marked.
In view of the above, as of now, there is no effective way to support ECN marking, especially in the DC scenario or the handover scenario. Therefore, there is a need for an improved solution for the ECN marking in such cases.
Embodiments of the present disclosure provide a solution for ECN marking. In one aspect of the solution of the present disclosure, a first RAN node receives, from a second RAN node, information associated with a congestion status at the second RAN node. Moreover, the first RAN node performs, based on the information, ECN marking for at least one quality of service (QoS) flow associated with a data radio bearer (DRB) , where the DRB is terminated at the first RAN node.
By considering the congestion status at the second RAN node, this solution allows ECN marking to be supported well especially in the DC scenario or in the CU-DU split scenario. In this way, it is possible to improve the flexibility of ECN marking and thus improve communication efficiency.
Principles and implementations of embodiments of the present disclosure will be described in detail below with reference to the figures.
FIG. 1A illustrates an example of a wireless communications system 100 that supports ECN marking in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more network entities 102 (also referred to as network equipment (NE) ) , one or more UEs 104, a core network 106, and a packet data network 108. The wireless communications system 100 may support various radio access technologies. In some implementations, the wireless communications system 100 may be a 4G network, such as a long term evolution (LTE) network or an LTE-Advanced (LTE-A) network. In some other implementations, the wireless communications system 100 may be a 5G network, such as a new radio (NR) network. In other implementations, the wireless communications system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technology including Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20. The wireless communications system 100 may support radio access technologies beyond 5G. Additionally, the wireless communications system 100 may support technologies, such as time division multiple access (TDMA) , frequency division multiple access (FDMA) , or code division multiple access (CDMA) , etc.
The one or more network entities 102 may be dispersed throughout a geographic region to form the wireless communications system 100. One or more of the network entities 102 described herein may be or include or may be referred to as a network node, a base station, a network element, a radio access network (RAN) , a base transceiver station, an access point, a NodeB, an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. A network entity 102 and a UE 104 may communicate via a communication link 110, which may be a wireless or wired connection. For example, a network entity 102 and a UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) over a Uu interface.
A network entity 102 may provide a geographic coverage area 112 for which the network entity 102 may support services (e.g., voice, video, packet data, messaging, broadcast, etc. ) for one or more UEs 104 within the geographic coverage area 112. For example, a network entity 102 and a UE 104 may support wireless communication of signals related to services (e.g., voice, video, packet data, messaging, broadcast, etc. ) according to one or multiple radio access technologies. In some implementations, a network entity 102 may be moveable, for example, a satellite associated with a non-terrestrial network. In some implementations, different geographic coverage areas 112 associated with the same or different radio access technologies may overlap, but the different geographic coverage areas 112 may be associated with different network entities 102. Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.
The one or more UEs 104 may be dispersed throughout a geographic region of the wireless communications system 100. A UE 104 may include or may be referred to as a mobile device, a wireless device, a remote device, a remote unit, a handheld device, or a subscriber device, or some other suitable terminology. In some implementations, the UE 104 may be referred to as a unit, a station, a terminal, or a client, among other examples. Additionally, or alternatively, the UE 104 may be referred to as an Internet-of-Things (IoT) device, an Internet-of-Everything (IoE) device, or machine-type communication (MTC) device, among other examples. In some implementations, a UE 104 may be stationary in the wireless communications system 100. In some other implementations, a UE 104 may be mobile in the wireless communications system 100.
The one or more UEs 104 may be devices in different forms or having different capabilities. Some examples of UEs 104 are illustrated in FIG. 1A. A UE 104 may be capable of communicating with various types of devices, such as the network entities 102, other UEs 104, or network equipment (e.g., the core network 106, the packet data network 108, a relay device, an integrated access and backhaul (IAB) node, or another network equipment) , as shown in FIG. 1A. Additionally, or alternatively, a UE 104 may support communication with other network entities 102 or UEs 104, which may act as relays in the wireless communications system 100.
A UE 104 may also be able to support wireless communication directly with other UEs 104 over a communication link 114. For example, a UE 104 may support wireless communication directly with another UE 104 over a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link 114 may be referred to as a sidelink (SL) . For example, a UE 104 may support wireless communication directly with another UE 104 over a PC5 interface.
A network entity 102 may support communications with the core network 106, or with another network entity 102, or both. For example, a network entity 102 may interface with the core network 106 through one or more backhaul links 116 (e.g., via an S1, N2, N2, or another network interface) . The network entities 102 may communicate with each other over the backhaul links 116 (e.g., via an X2, Xn, or another network interface) . In some implementations, the network entities 102 may communicate with each other directly (e.g., between the network entities 102) . In some other implementations, the network entities 102 may communicate with each other or indirectly (e.g., via the core network 106) . In some implementations, one or more network entities 102 may include subcomponents, such as an access network entity, which may be an example of an access node controller (ANC) . An ANC may communicate with the one or more UEs 104 through one or more other access network transmission entities, which may be referred to as a radio heads, smart radio heads, or transmission-reception points (TRPs) .
In some implementations, a network entity 102 may be configured in a disaggregated architecture, which may be configured to utilize a protocol stack physically or logically distributed among two or more network entities 102, such as an integrated access backhaul (IAB) network, an open RAN (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance) , or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN) ) . For example, a network entity 102 may include one or more of a central unit (CU) , a distributed unit (DU) , a radio unit (RU) , a RAN Intelligent Controller (RIC) (e.g., a Near-Real Time RIC (Near-RT RIC) , a Non-Real Time RIC (Non-RT RIC) ) , a Service Management and Orchestration (SMO) system, or any combination thereof.
An RU may also be referred to as a radio head, a smart radio head, a remote radio head (RRH) , a remote radio unit (RRU) , or a transmission reception point (TRP) . One or more components of the network entities 102 in a disaggregated RAN architecture may be co-located, or one or more components of the network entities 102 may be located in distributed locations (e.g., separate physical locations) . In some implementations, one or more network entities 102 of a disaggregated RAN architecture may be implemented as virtual units (e.g., a virtual CU (VCU) , a virtual DU (VDU) , a virtual RU (VRU) ) .
Split of functionality between a CU, a DU, and an RU may be flexible and may support different functionalities depending upon which functions (e.g., network layer functions, protocol layer functions, baseband functions, radio frequency functions, and any combinations thereof) are performed at a CU, a DU, or an RU. For example, a functional split of a protocol stack may be employed between a CU and a DU such that the CU may support one or more layers of the protocol stack and the DU may support one or more different layers of the protocol stack. In some implementations, the CU may host upper protocol layer (e.g., a layer 3 (L3) , a layer 2 (L2) ) functionality and signaling (e.g., Radio Resource Control (RRC) , service data adaption protocol (SDAP) , Packet Data Convergence Protocol (PDCP) ) . The CU may be connected to one or more DUs or RUs, and the one or more DUs or RUs may host lower protocol layers, such as a layer 1 (L1) (e.g., physical (PHY) layer) or an L2 (e.g., radio link control (RLC) layer, medium access control (MAC) layer) functionality and signaling, and may each be at least partially controlled by the CU.
Additionally, or alternatively, a functional split of the protocol stack may be employed between a DU and an RU such that the DU may support one or more layers of the protocol stack and the RU may support one or more different layers of the protocol stack. The DU may support one or multiple different cells (e.g., via one or more RUs) . In some implementations, a functional split between a CU and a DU, or between a DU and an RU may be within a protocol layer (e.g., some functions for a protocol layer may be performed by one of a CU, a DU, or an RU, while other functions of the protocol layer are performed by a different one of the CU, the DU, or the RU) .
A CU may be functionally split further into CU control plane (CU-CP) and CU user plane (CU-UP) functions. A CU may be connected to one or more DUs via a midhaul communication link (e.g., F1, F1 c, F1 u) , and a DU may be connected to one or more RUs via a fronthaul communication link (e.g., open fronthaul (FH) interface) . In some implementations, a midhaul communication link or a fronthaul communication link may be implemented in accordance with an interface (e.g., a channel) between layers of a protocol stack supported by respective network entities 102 that are in communication via such communication links .
The core network 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The core network 106 may be an evolved packet core (EPC) , or a 5G core (5GC) , which may include a control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management functions (AMF) ) and a user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . In some implementations, the control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signal bearers, etc. ) for the one or more UEs 104 served by the one or more network entities 102 associated with the core network 106.
The core network 106 may communicate with the packet data network 108 over one or more backhaul links 116 (e.g., via an S1, N2, N3, or another network interface) . The packet data network 108 may include an application server 118. In some implementations, one or more UEs 104 may communicate with the application server 118. A UE 104 may establish a session (e.g., a protocol data unit (PDU) session, or the like) with the core network 106 via a network entity 102. The core network 106 may route traffic (e.g., control information, data, and the like) between the UE 104 and the application server 118 using the established session (e.g., the established PDU session) . The PDU session may be an example of a logical connection between the UE 104 and the core network 106 (e.g., one or more network functions of the core network 106) .
In the wireless communications system 100, the network entities 102 and the UEs 104 may use resources of the wireless communications system 100 (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) ) to perform various operations (e.g., wireless communications) . In some implementations, the network entities 102 and the UEs 104 may support different resource structures. For example, the network entities 102 and the UEs 104 may support different frame structures. In some implementations, such as in 4G, the network entities 102 and the UEs 104 may support a single frame structure. In some other implementations, such as in 5G and among other suitable radio access technologies, the network entities 102 and the UEs 104 may support various frame structures (i.e., multiple frame structures) . The network entities 102 and the UEs 104 may support various frame structures based on one or more numerologies.
One or more numerologies may be supported in the wireless communications system 100, and a numerology may include a subcarrier spacing and a cyclic prefix. A first numerology (e.g., μ=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a normal cyclic prefix. In some implementations, the first numerology (e.g., μ=0) associated with the first subcarrier spacing (e.g., 15 kHz) may utilize one slot per subframe. A second numerology (e.g., μ=1) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a normal cyclic prefix. A third numerology (e.g., μ=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth numerology (e.g., μ=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a normal cyclic prefix. A fifth numerology (e.g., μ=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a normal cyclic prefix.
A time interval of a resource (e.g., a communication resource) may be organized according to frames (also referred to as radio frames) . Each frame may have a duration, for example, a 10 millisecond (ms) duration. In some implementations, each frame may include multiple subframes. For example, each frame may include 10 subframes, and each subframe may have a duration, for example, a 1 ms duration. In some implementations, each frame may have the same duration. In some implementations, each subframe of a frame may have the same duration.
Additionally or alternatively, a time interval of a resource (e.g., a communication resource) may be organized according to slots. For example, a subframe may include a number (e.g., quantity) of slots. The number of slots in each subframe may also depend on the one or more numerologies supported in the wireless communications system 100. For instance, the first, second, third, fourth, and fifth numerologies (i.e., μ=0, μ=1, μ=2, μ=3, μ=4) associated with respective subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may utilize a single slot per subframe, two slots per subframe, four slots per subframe, eight slots per subframe, and 16 slots per subframe, respectively. Each slot may include a number (e.g., quantity) of symbols (e.g., OFDM symbols) . In some implementations, the number (e.g., quantity) of slots for a subframe may depend on a numerology. For a normal cyclic prefix, a slot may include 14 symbols. For an extended cyclic prefix (e.g., applicable for 60 kHz subcarrier spacing) , a slot may include 12 symbols. The relationship between the number of symbols per slot, the number of slots per subframe, and the number of slots per frame for a normal cyclic prefix and an extended cyclic prefix may depend on a numerology. It should be understood that reference to a first numerology (e.g., μ=0) associated with a first subcarrier spacing (e.g., 15 kHz) may be used interchangeably between subframes and slots.
In the wireless communications system 100, an electromagnetic (EM) spectrum may be split, based on frequency or wavelength, into various classes, frequency bands, frequency channels, etc. By way of example, the wireless communications system 100 may support one or multiple operating frequency bands, such as frequency range designations FR1 (410 MHz –7.125 GHz) , FR2 (24.25 GHz –52.6 GHz) , FR3 (7.125 GHz –24.25 GHz) , FR4 (52.6 GHz –114.25 GHz) , FR4a or FR4-1 (52.6 GHz –71 GHz) , and FR5 (114.25 GHz –300 GHz) . In some implementations, the network entities 102 and the UEs 104 may perform wireless communications over one or more of the operating frequency bands. In some implementations, FR1 may be used by the network entities 102 and the UEs 104, among other equipment or devices for cellular communications traffic (e.g., control information, data) . In some implementations, FR2 may be used by the network entities 102 and the UEs 104, among other equipment or devices for short-range, high data rate capabilities.
FR1 may be associated with one or multiple numerologies (e.g., at least three numerologies) . For example, FR1 may be associated with a first numerology (e.g., μ=0) , which includes 15 kHz subcarrier spacing; a second numerology (e.g., μ=1) , which includes 30 kHz subcarrier spacing; and a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing. FR2 may be associated with one or multiple numerologies (e.g., at least 2 numerologies) . For example, FR2 may be associated with a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing; and a fourth numerology (e.g., μ=3) , which includes 120 kHz subcarrier spacing.
FIG. 1B illustrates an example of a wireless communications system 120 that supports ECN marking in the DC scenario in accordance with aspects of the present disclosure. Specifically, FIG. 1B illustrates similar entities or functions as shown in FIG. 1A. For example, the details discussed above regarding the network entities 102 and the UE 104 with reference to FIG. 1A applies to FIG. 1B. For the purpose of simplification, the details will be omitted.
As shown in FIG. 1B, the wireless communications system 120 may include a master RAN node 122, a secondary RAN node 124, and a UE 126. The master RAN node 122 and the secondary RAN node 124 may be served as DC for the UE 126.
In some embodiments, the UE 126 may be configured to utilize radio resources provided by two distinct schedulers, located in the master RAN node 122 and the secondary RAN node 124 respectively connected via a non-ideal backhaul, one providing new radio (NR) access and the other one providing either Evolved Universal Terrestrial Radio Access (E-UTRA) or NR access.
FIG. 1C illustrates an example of a wireless communications system 130 that supports ECN marking in the CU-DU split scenario in accordance with aspects of the present disclosure. Specifically, FIG. 1C illustrates similar entities or functions as shown in FIG. 1A. For example, the details discussed above regarding the network entities 102 and the UE 104 with reference to FIG. 1A applies to FIG. 1C. For the purpose of simplification, the details will be omitted.
As shown in FIG. 1C, the wireless communications system 130 may include a BS 132 and a UE 134. The BS 132 may comprise a CU 136 and a DU 138. For example, the DU 138 may be under the control of the CU 136. Some functions of the BS 132 may be deployed on the CU 136, and other functions may be deployed on the DU 138 as described above with reference to FIG. 1A. For example, the CU 136 may be responsible for some higher-level protocol stack functions and the DU 138 may be responsible for lower-level protocol stack functions. Moreover, the CU 136 may be functionally split further into a CP 140 and a UP 142 connecting via an E1 interface.
FIG. 1D illustrates an example of a wireless communications system 150 that supports ECN marking in the handover scenario in accordance with aspects of the present disclosure. Specifically, FIG. 1D illustrates similar entities or functions as shown in FIG. 1A. For example, the details discussed above regarding the network entities 102 and the UE 104 with reference to FIG. 1A applies to FIG. 1D. For the purpose of simplification, the details will be omitted.
As shown in FIG. 1D, the wireless communications system 150 may include gNBs 152 and 154 (also referred to as a source gNB (S-gNB) 152 and a target gNB (T-gNB) 154 respectively in the handover scenario) , and a UE 156. In some embodiments, the UE 156 may be configured to hand over from the source gNB 152 to the target gNB 154. In this case, data forwarding may be needed from the source gNB 152 to the target gNB 154, for example, for further transmission from the target gNB 154 to the UE 156.
FIG. 1E illustrates an example diagram of ECN codepoints associated with aspects of the present disclosure. The functionality is given by the ECN field in the IP packet header with two bits, making four ECN codepoints, ‘00’ to ‘11’ . The ECN-capable transport (ECT) code points ‘10’ and ‘01’ are set by the data sender to indicate that the endpoints of the transport protocol are ECN-capable. The ECN-capable transport (ECT) code points ‘10’ and ‘01’ may be called ECT (0) and ECT (1) respectively. The ECT code point ‘00’ is used to indicate that ECT is not supported, and the ECT code point ‘11’ is used to indicate that congestion is experienced.
FIG. 1F illustrates an example overview procedure of ECN marking associated with aspects of the present disclosure. As shown in FIG. 1F, at step 1, negotiation is performed over transport protocol if the sender and receiver are both ECN capable. The sender marks ECT (0) or ECT (1) in the IP header of the transmitted packets. At step 2, for uplink (UL) congestion, an NG-RAN node (i.e., a router) marks UL packets in the IP header with CE (congestion experience) , and for DL congestion, the NG-RAN marks DL packets the same way. At step 3, for UL congestion, the application server sends an ECN-Echo (ECE) (for example, a acknowledge (ACK) packet with an ECE flag in the TCP header) to the UE, and for DL congestion, the UE sends an ECE to the application server. At step 4, upon receiving the ECE, the sender knows that congestion happens on the path from the sender to the receiver. Then, the sender may inform the receiver that the congestion window has been reduced by setting the congestion window reduced (CWR) flag in the TCP header.
In MR-DC, from a UE perspective, three bearer types exist, that is, MCG bearer, SCG bearer, and split bearer. These three bearer types are depicted with reference to FIGS. 1G and 1E, where FIG. 1G illustrates an example radio protocol architecture for MCG, SCG and split bearers from a UE perspective in multi-radio access technology (RAT) DC (MR-DC) with EPC (E-UTRA NR DC (EN-DC) ) associated with aspects of the present disclosure, and FIG. 1H illustrates an example radio protocol architecture for MCG, SCG and split bearers from a UE perspective in MR-DC with 5GC (NG RAN E-UTRA DC (NGEN-DC) , NE-DC, and NR-DC) associated with aspects of the present disclosure.
In E-UTRA connected to EPC, if the UE supports EN-DC, regardless of whether EN-DC is configured or not, the network can configure either E-UTRA PDCP or NR PDCP for MN terminated MCG bearers while NR PDCP is always used for all other bearers. Change from E-UTRA to NR PDCP or vice-versa can be performed via a reconfiguration procedure (with or without handover) , either using release and add of the DRBs or using the full configuration option.
In MR-DC with 5GC, NR PDCP is always used for all bearer types. In NGEN-DC, E-UTRA RLC/MAC is used in the MN while NR RLC/MAC is used in the SN. In NE-DC, NR RLC/MAC is used in the MN while E-UTRA RLC/MAC is used in the SN. In NR-DC, NR RLC/MAC is used in both MN and SN.
From a network perspective, each bearer (MCG, SCG or split bearer) may be terminated either in the MN or in the SN. Network-side protocol termination options are shown in FIGS. 1I and 1J, where FIG. 1I illustrates network side protocol termination options for MCG, SCG and split bearers in MR-DC with EPC (EN-DC) associated with aspects of the present disclosure, and FIG. 1J illustrates network side protocol termination options for MCG, SCG and split bearers in MR-DC with 5GC (NGEN-DC, NE-DC and NR-DC) associated with aspects of the present disclosure.
Reference is now made to FIG. 2, which illustrates an example signaling chart of a communication process that supports ECN marking in DC in accordance with aspects of the present disclosure. For the purpose of discussion, the process 200 will be described with reference to FIGS. 1B and 1C. The process 200 may involve the first RAN node 201 and the second RAN node 202. It is to be understood that the steps and the order of the steps in FIG. 2 are merely for illustration, and not for limitation. It is to be understood that process 200 may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard. It would be also appreciated that the process 200 may be applied to other communication scenarios, which will not be described in detail.
As shown in FIG. 2, at 205, the second RAN node 202 determines information associated with a congestion status at the second RAN node 202. Then, at 210, the second RAN node 202 transmits the information to the first RAN node 201. On the other side of communication, the first RAN node 201 receives the information from the second RAN node 202. Then, at 215, the first RAN node 201 performs, based on the information, ECN marking for at least one QoS flow associated with a DRB. The DRB to which the at least one QoS flow is mapped is terminated at the first RAN node 201.
Details on the process 200 embodied in different application scenarios will be discussed below respectively.
CP-based ECN marking
For MN terminated bearer
In this case, the first RAN node 201 may be implemented by the master RAN node (also referred to as MN) 122 as shown in FIG. 1B, and the second RAN node 202 may be implemented by the secondary RAN node (also referred to as SN) 124 as shown in FIG. 1B.
In MR-DC with 5GC, the first RAN node 201 may decide per PDU session location of an SDAP entity whether it may be hosted by the first RAN node 201 or the second RAN node 202 or by both (i.e., split PDU session) . If the first RAN node 201 decides to host the SDAP entity and/or PDCP entity, some of the related QoS flows may be realized as an MCG bearer, some as an SCG bearer, while others to be realized as a split bearer, in which case the bearers may be called as an MN terminated MCG bearer, an MN terminated SCG bearer and an MN terminated split bearer respectively. The MN terminated SCG bearer case and the MN terminated split bearer are taken as examples in the following discussions.
In some examples, the first RAN node 201 may request, from the second RAN node 202, the information associated with the congestion status at the second RAN node 202. As an example, the first RAN node 201 may transmit a request for the information to the second RAN node 202. Then, after receiving the request, the second RAN node 202 may feedback the information per the received request. For example, the information may comprise a suggested ECN marking policy. The information may be comprised in a SECONDARY NODE (S-NODE) MODIFICATION REQUIRED message.
As an implementation, the request may comprise a periodicity for the second RAN node 202 to transmit the information. Upon reception of the request, the second RAN node 202 may provide the information periodically according to the periodicity indicated in the request.
As another implementation, the request may comprise at least one event to trigger the second RAN node 202 to transmit the information. Upon reception of the request, the second RAN node 202 may feedback the information if the configured event is fulfilled. For example, an event may comprise a congestion level associated with the second RAN node 202 being above a congestion level threshold. In this case, the second RAN node 202 may feedback the information if it determines that the congestion level is above the congestion level threshold. For instance, an event may comprise a congestion ratio associated with the second RAN node 202 being above a congestion ratio threshold. In this case, the second RAN node 202 may feedback the information if it determines that the congestion ratio is above the congestion ratio threshold.
In some embodiments, the first RAN node 201 may transmit, to the second RAN node 202, a congestion enable indication that the ECN marking for the DRB or the at least one QoS flow is required. The congestion enable indication may be per QoS flow or per DRB. As an example, the congestion enable indication may be comprised in an S-NODE ADDITION REQUEST message or an S-NODE MODIFICATION REQUEST message.
For example, the congestion enable indication may comprise an L4S Enable Indication. The L4S Enable Indication may indicate to the second RAN node 202 that ECN marking for L4S for the QoS flow or the DRB is required. The L4S Enable Indication may be included in the PDU Session Resource Setup Info –MN terminated IE in the S-NODE ADDITION REQUEST message or the S-NODE MODIFICATION REQUEST message.
In some embodiments, the congestion enable indication may be transmitted to the secondary RAN node 124 before the request. In some other embodiments, the congestion enable indication and the request may be carried in a same message.
In some other embodiments, the congestion enable indication may implicitly indicate the request for the information as described above. For example, the L4S enable indication may indicate that the second RAN node 202 needs to feedback the information to the first RAN node 201. The congestion enable indication may comprise the above-mentioned information included in the request.
As an implementation, the provided information associated with the congestion status at the second RAN node 202 may comprise an indication to perform ECN marking for partial or all packets received from or to be transmitted to the second RAN node 202 of the DRB or the at least one QoS flow. The information may indicate the first RAN node 201 to mark the ECN bits of one or some or all packets of the QoS flow/DRB that tends to be transmitted to the UE 126 via the second RAN node 202, e.g., for downlink transmission. The information may indicate the first RAN node 201 to mark the ECN bits of one or some or all packets of the QoS flow/DRB that are received from the second RAN node 202 e.g., for UL data transmission.
As another implementation, the information may comprise a suggested ratio (or percentage) of packets of the DRB or the at least one QoS flow to be ECN marked, where the packets are received from the second RAN node 202 or to be transmitted to the second RAN node 202. The information may indicate, to first RAN node 201, the ratio or percentage of packets to be marked with ECN bits for data transmission via the second RAN node 202, e.g., the packets tend to be transmitted via the second RAN node 202 to the UE 126 or received from the second RAN node 202.
As a further implementation, the information may comprise a congestion level associated with the second RAN node 202. The information may indicate the congestion level of the second RAN node 202. In an example, four congestion levels may be defined as (0, 1, 2, 3) , where the value ‘3’ may represent the highest congestion level, and the value ‘0’ may represent the lowest congestion level. In another example, the congestion level may be a percentage of the congestion, where ‘100%’ may represent the highest congestion degree and in this case there is fully congested, and ‘0%’ may represent the lowest congestion degree and in this case there is no congestion. The congestion level may be per QoS flow level or per DRB level or per cell level (e.g., per primary secondary cell (PSCell) level) or per node level (e.g., per SN level) or per cell group level (e.g., per SCG level) .
Upon reception of the information, the first RAN node 201 may perform the ECN marking. The first RAN node 201 may mark ECN bits of user IP packets of the at least one QoS flow according to the information from the second RAN node 202.
For DL data transmission, the first RAN node 201 may receive packets (such as SDAP SDUs) of the at least one QoS flow from the UPF. The first RAN node 201 may mark the ECN bits in the user IP header of the packets that will be transmitted to the second RAN node 202 according to the information. If the information indicates one or some or all packets should be marked, the first RAN node 201 may mark the ECN bits of the one or some or all packets that will be transmitted to the second RAN node 202. If the information indicates the ratio or percentage of packets to be marked with ECN bits, the first RAN node 201 may mark the ECN bits in the user IP header for the percentage or ratio of the packets. For example, if the suggested ratio is 50%, the first RAN node 201 may select 50%packets for the ECN marking. After ECN marking, the packets may be processed by the PDCP layer. Then, the first RAN node 201 may transmit the PDCP PDUs with ECN marking inside to the second RAN node 202. Further, the second RAN node 202 may transmit the PDCP PDUs to the UE 126. Then, the UE 126 may handle the ECN marking accordingly.
For UL data transmission, the second RAN node 202 may receive the PDCP PDUs from the UE 126 and forward the PDCP PDUs to the first RAN node 201. Upon receiving the PDCP PDUs from the second RAN node 202, the first RAN node 201 may process them to the SDAP SDUs, and mark the ECN bits in the user IP header of the packets according to the information obtained from the second RAN node 202. Then, the first RAN node 201 may transmit the SDAP SDUs with ECN marking to the UPF.
In some embodiments, the first RAN node 201 may perform the ECN marking based on a congestion status at the first RAN node 201 and the information received from the second RAN node 202. In other words, the first RAN node 201 may mark the ECN bits taking both the congestion status at the first RAN node 201 and the congestion status at the second RAN node 202 into account. In an implementation, if the information indicates that the suggested ratio or percentage of packets to be marked with ECN bits is 50%while the marking ratio or percentage of packets required to be marked at the first RAN node 201 is 30%, the first RAN node 201 may assume that half of the data is transmitted by the first RAN node 201 and the another half of the data is transmitted by the second RAN node 202, and then determine the final ECN marking ratio to be (50%+30%) /2 = 40%.
FIG. 3 illustrates an example communication process that supports ECN marking in DC in accordance with aspects of the present disclosure. For the purpose of discussion, the process 300 will be described with reference to FIG. 1B. The process 300 may involve the master RAN node (also referred to as MN) 122, the secondary RAN node (also referred to as SN) 124, the UE 126, and the UPF 301. It is to be understood that the steps and the order of the steps in FIG. 3 are merely for illustration, and not for limitation. It is to be understood that process 300 may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard.
As shown in FIG. 3, at 305, the MN 122 transmits an L4S Enable Indication to the SN 124. The L4S Enable Indication may indicate that the ECN marking for the DRB or the QoS flow is required. In some examples, at 307, the MN 122 may transmit, to the SN 124, a request for information associated with a congestion status at the SN 124. Alternatively or additionally, the L4S enable indication may indicate that the SN 124 needs to feedback the congestion information to the MN 122. In other words, in this case, the L4S enable indication may implicitly indicate the request for the information.
At 310, the SN 124 transmits information associated with the congestion status at the SN 124 to the MN 122 according to the L4S Enable Indication. After receiving data from the UPF 301 at 315, the MN 122 marks, at 320, ECN bits of user IP packets of the QoS flow according to the information from the MN 122. At 325, the MN 122 transmits the marked data to the SN 124. At 330 and 335, DL data transmission via MCG and SCG is performed respectively.
Operations and features as described above with reference to the MN terminated bearer case are likewise applicable to the process 300 and have similar effects. For the purpose of simplification, the details will be omitted.
For SN terminated bearer
In this case, the first RAN node 201 may be implemented by the secondary RAN node (also referred to as SN) 124 as shown in FIG. 1B, and the second RAN node 202 may be implemented by the master RAN node (also referred to as MN) 122 as shown in FIG. 1B.
In MR-DC with 5GC, the first RAN node 201 may decide per PDU session location of an SDAP entity whether it may be hosted by the first RAN node 201 or the second RAN node 202 or by both (i.e., split PDU session) . If the first RAN node 201 decides that the SDAP entity shall be hosted in the second RAN node 202, some of the related QoS flows may be realized as an SCG bearer, some as an MCG bearer, while others may be realized as a split bearer, in which case the bearers may be called as an SN terminated SCG bearer, an SN terminated MCG bearers and an SN terminated split bearer. The SN terminated MCG bearer case and the SN terminated split bearer are taken as examples in the following discussions.
In some embodiments, the second RAN node 202 may transmit, to the first RAN node 201, a congestion enable indication that the ECN marking for the DRB or the at least one QoS flow is required. The congestion enable indication may be per QoS flow or per DRB. As an example, the congestion enable indication may be comprised in an S-NODE ADDITION REQUEST or an S-NODE MODIFICATION REQUEST message.
For example, the congestion enable indication may comprise an L4S Enable Indication. The L4S Enable Indication may indicate to the second RAN node 202 that ECN marking for L4S for the QoS flow or the DRB is required. The L4S Enable Indication may be included in the PDU Session Resource Setup Info –SN terminated IE in the S-NODE ADDITION REQUEST message or the S-NODE MODIFICATION REQUEST message.
Likewise, in some examples, the first RAN node 201 may request, from the second RAN node 202, the information associated with the congestion status at the second RAN node 202. Details about the request for the information and the network side behaviors associated with the request are similar as those described above with reference to the MN terminated bearer case. For the purpose of simplification, the details will be omitted.
Then, the second RAN node 202 may transmit the information to the first RAN node 201, and the first RAN node 201 may perform the ECN marking accordingly. Details about the information and the network side behaviors associated with performing the ECN marking are similar as those described above with reference to the MN terminated bearer case. For the purpose of simplification, the details will be omitted.
For CU-DU split case
In this case, the first RAN node 201 may be implemented by the CU 136 as shown in FIG. 1C, and the second RAN node 202 may be implemented by the DU 138 as shown in FIG. 1C. As the SDAP and PDCP layers or functionalities may be terminated in the CU 136, the PDCP terminated node may be the CU 136 while the peer node is the DU 138.
Likewise, in some examples, the first RAN node 201 may request, from the second RAN node 202, the information associated with the congestion status at the second RAN node 202. Details about the request for the information and the network side behaviors associated with the request are similar as those described above with reference to the MN terminated bearer case. For the purpose of simplification, the details will be omitted.
- In some embodiments, the second RAN node 202 may transmit, to the first RAN node 201, a congestion enable indication that the ECN marking for the DRB or the at least one QoS flow is required, for example, over the F1 application protocol (F1-AP) . Details about the congestion enable indication and the network side behaviors associated with the congestion enable indication are similar as those described above with reference to the MN terminated bearer case. For the purpose of simplification, the details will be omitted.
Then, the second RAN node 202 may transmit the information to the first RAN node 201 over the F1-AP. The gNB-CU may then perform ECN marking accordingly. Details about the information and the network side behaviors associated with performing the ECN marking are similar as those described above with reference to the MN terminated bearer case. For the purpose of simplification, the details will be omitted.
- Furthermore, in case of CU-CP and CU-UP split, the PDCP entity may be terminated in the UP 142 of the CU 136. In this case, the CP 140 may transmit a congestion enable indication to the UP 142 over the E1-AP. Details about the congestion enable indication and the network side behaviors associated with the congestion enable indication are similar as those described above with reference to the MN terminated bearer case. For the purpose of simplification, the details will be omitted. The DU 138 may transmit information associated with the congestion status at the DU 138 to the CP 140 over the F1-AP. Details about the request for the information and the network side behaviors associated with the request are similar as those described above with reference to the MN terminated bearer case. For the purpose of simplification, the details will be omitted. The CP 140 may forward the information to the UP 142 over the E1-AP. The UP 142 may perform ECN marking accordingly. For example, The UP 142 may mark ECN bits of user IP packets of a QoS flow according to the information obtained from the DU 138 and its’ own congestion status. Details about the information and the network side behaviors associated with performing the ECN marking are similar as those described above with reference to the MN terminated bearer case. For the purpose of simplification, the details will be omitted.
UP-based ECN marking
For MN terminated bearer
In this case, the first RAN node 201 may be implemented by the master RAN node (also referred to as MN) 122 as shown in FIG. 1B, and the second RAN node 202 may be implemented by the secondary RAN node (also referred to as MN) 124 as shown in FIG. 1B.
In MR-DC with 5GC, the first RAN node 201 may decide per PDU session location of an SDAP entity whether it may be hosted by the first RAN node 201 or the second RAN node 202 or by both (i.e., split PDU session) . If the first RAN node 201 decides to host the SDAP entity, some of the related QoS flows may be realized as an MCG bearer, some as an SCG bearer, while others to be realized as a split bearer, in which case the bearers may be called as an MN terminated MCG bearer, an MN terminated SCG bearer and an MN terminated split bearer respectively. The MN terminated SCG bearer case and the MN terminated split bearer are taken as examples in the following discussions.
Likewise, in some examples, the first RAN node 201 may request, from the second RAN node 202, the information associated with the congestion status at the second RAN node 202. Details about the request for the information and the network side behaviors associated with the request are similar as those described above with reference to the MN terminated bearer case on the basis of CP-based ECN marking. For the purpose of simplification, the details will be omitted.
Likewise, in some embodiments, the first RAN node 201 may transmit, to the second RAN node 202, a congestion enable indication that the ECN marking for the DRB or the at least one QoS flow is required. Details about the congestion enable indication and the network side behaviors associated with the congestion enable indication are similar as those described above with reference to the MN terminated bearer case on the basis of CP-based ECN marking. For the purpose of simplification, the details will be omitted.
For example, upon receiving the request or the congestion enable indication, the second RAN node 202 may provide the information to the first RAN node 201. The information may be comprised in a general packet radio service tunneling protocol user plane (GTP-U) extension header, for example, in the ‘RAN container’ of the GTP-U extension header, e.g., in the Downlink Data Delivery Status frame. For example, the information may be per UL and DL respectively. The information may be an implicit indication represented by existing flow control information, i.e., the information in the Downlink Data Delivery Status frame.
As an implementation, the information associated with the congestion status at the second RAN node 202 comprises an indication indicating whether there is congestion experienced at the second RAN node 202. The information may comprise one bit to indicate whether there is congestion experienced. For example, the value ‘0’ may represent there is no congestion experienced while the value ‘1’ may represent there is congestion experienced. As another example, the information may comprise two bits to indicate whether there is congestion experienced. For example, the value ‘00’ may represent there is no congestion experienced while the value ‘11’ may represent there is congestion experienced.
As another example, the information may comprise a suggested ratio (or percentage) of packets received from or to be transmitted to the second RAN node 202 of the DRB or the at least one QoS flow to be ECN marked. The information may indicate, to first RAN node 201, the ratio or percentage of packets to be marked with ECN bits for data transmission via the second RAN node 202, e.g., the packets tend to be transmitted via the second RAN node 202 to the UE 126 or received from the second RAN node 202.
As a further implementation, the information may comprise a congestion level associated with the second RAN node 202. The information may comprise the congestion level of the second RAN node 202. In an example, four congestion levels may be defined as (0, 1, 2, 3) , where the value ‘3’ may represent the highest congestion level, and the value ‘0’ may represent the lowest congestion level. In another example, the congestion level may be a percentage of the congestion, where ‘100%’ may represent the highest congestion degree and in this case there is fully congested, and ‘0%’ may represent the lowest congestion degree and in this case there is no congestion. The congestion level may be per QoS flow level or per DRB level or per cell level.
Upon reception of the information, the first RAN node 201 may perform the ECN marking. FIG. 4 illustrates a schematic diagram of ECN marking in accordance with aspects of the present disclosure. As shown in FIG. 4, after receiving the information in the GTP-U header, the first RAN node 201 may mark the ECN bits in the user IP header of the packets correspondingly. More details about the network side behaviors associated with performing the ECN marking are similar as those described above with reference to the MN terminated bearer case on the basis of CP-based ECN marking. For the purpose of simplification, the details will be omitted.
FIG. 5 illustrates another example communication process that supports ECN marking in DC in accordance with aspects of the present disclosure. For the purpose of discussion, the process 500 will be described with reference to FIG. 1B. The process 500 may involve the master RAN node (also referred to as MN) 122, the secondary RAN node (also referred to as SN) 124, the UE 126, and the UPF 501. It is to be understood that the steps and the order of the steps in FIG. 5 are merely for illustration, and not for limitation. It is to be understood that process 500 may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard.
As shown in FIG. 5, at 505, the MN 122 transmits an L4S Enable Indication to the SN 124. The L4S Enable Indication may indicate that the ECN marking for the DRB or the QoS flow is required. In some examples, at 507, the MN 122 may transmit, to the SN 124, a request for information associated with a congestion status at the SN 124. Alternatively or additionally, the L4S enable indication may indicate that the SN 124 needs to feedback the congestion information to the MN 122. In other words, in this case, the L4S enable indication may implicitly indicate the request for the information.
At 510 and 515, UL data transmission via MCG and SCG is performed respectively. At 520, the SN 124 puts the information associated with the congestion status at the SN 124 in the GTP-U extension header. At 525, the SN 124 transmits the information to the MN 122. At 530, the MN 122 ECN bits of user IP packets of the QoS flow according to the information in the GTP-U extension header from the MN 122 and its’ own congestion status. At 535, the MN transmits the marked data to the UPF 501.
Operations and features as described above with reference to the MN terminated bearer case are likewise applicable to the process 500 and have similar effects. For the purpose of simplification, the details will be omitted.
For SN terminated bearer
In this case, the first RAN node 201 may be implemented by the secondary RAN node 124 as shown in FIG. 1B, and the second RAN node 202 may be implemented by the master RAN node 122 as shown in FIG. 1B.
The similar method as described above with reference to the SN terminated bearer case on the basis of CP-based ECN marking may be applied combining the method as described above with reference to the MN terminated bearer case on the basis of UP-based ECN marking.
For CU-DU split case
In this case, the first RAN node 201 may be implemented by the CU 136 as shown in FIG. 1C, and the second RAN node 202 may be implemented by the DU 138 as shown in FIG. 1C. As the PDCP may be terminated in the CU 136, the PDCP terminated node may be the CU 136 while the peer node is the DU 138.
For CU-DU split and CU-CP/CU-UP split case, the similar method as described above with reference to the CU-DU split case on the basis of CP-based ECN marking may be applied combining the method as described above with reference to the MN terminated bearer case on the basis of UP-based ECN marking.
UPF-based ECN marking
Similar methods also apply to UPF based ECN marking cases. In some embodiments using UPF based ECN marking, in case of MR-DC, CU-DU split and CU-CP/CU-UP split, the peer node (for example, the SN) may provide the PDCP terminated node (for example, the MN) information associated with the congestion status at the peer node (for example, a suggested ECN marking policy) via the control plane (e.g., by control signaling) or via the UP (e.g., by the GTP-U extension header) in the same way as described above with reference to FIG. 2. For the purpose of simplification, the details will be omitted. The PDCP terminated node may provide congestion information to the UPF according to its own congestion status and the received information from the peer node. Then, the UPF may perform ECN marking based on the obtained congestion information.
According to some embodiments described with reference to FIGS. 2-5, it is allowed to support ECN marking well in the DC scenario or the CU-DU split scenario. In this way, it is possible to improve the flexibility of ECN marking and thus improve communication efficiency.
FIG. 6 illustrates an example signaling chart of a communication process that supports ECN marking during handover in accordance with aspects of the present disclosure. For the purpose of discussion, the process 600 will be described with reference to FIG. 1D. The process 600 may involve the S-gNB 152 and the T-gNB 154. It is to be understood that the steps and the order of the steps in FIG. 6 are merely for illustration, and not for limitation. It is to be understood that process 600 may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard. It would be also appreciated that the process 600 may be applied to other communication scenarios, which will not be described in detail.
As shown in FIG. 6, at 605, the S-gNB 152 transmits an L4S enable indication to the T-gNB 154. The L4S Enable Indication may indicate to the T-gNB 154 that ECN marking for L4S for the QoS flow or the DRB is required. Alternatively or additionally, the L4S enable indication may indicate that the T-gNB 154 needs to feedback the congestion information associated with a congestion status at the T-gNB 154. The L4S Enable Indication may be comprised in the HANDOVER REQUEST message. More details about the congestion information and the L4S Enable Indication are similar as those described above with reference to FIG. 2. For the purpose of simplification, the details will be omitted.
At 610, the S-gNB 152 transmits an ECN Marking Indication to the T-gNB 154. The ECN Marking Indication may indicate whether ECN bits have been marked for one or more packets of the QoS flow or the DRB. For example, the ECN Marking Indication may also be included in the HANDOVER REQUEST or may be provided in the GTP-U extension header of the forwarded data.
At 615, the T-gNB 154 resets or re-marks the ECN bits of forwarded data according to the L4S enable indication and the ECN Marking Indication. In case there is no congestion in the T-gNB 154, the target gNB 154 may reset the ECN bits to be ‘00’ from ‘11’ if the L4S enable indication is provided from the S-gNB 152. More details about the ECN marking are similar as those described above with reference to FIG. 2. For the purpose of simplification, the details will be omitted.
FIG. 7 illustrates another example signaling chart of a communication process that supports ECN marking during handover in accordance with aspects of the present disclosure. For the purpose of discussion, the process 700 will be described with reference to FIG. 1D. The process 700 may involve the S-gNB 152 and the T-gNB 154. It is to be understood that the steps and the order of the steps in FIG. 7 are merely for illustration, and not for limitation. It is to be understood that process 700 may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard. It would be also appreciated that the process 700 may be applied to other communication scenarios, which will not be described in detail.
As shown in FIG. 7, at 705, the S-gNB 152 transmit an L4S enable indication to the T-gNB 154. For example, the L4S Enable Indication may be comprised in the HANDOVER REQUEST message. More details about the L4S Enable Indication are similar as those described above with reference to FIG. 2. For the purpose of simplification, the details will be omitted.
- At 710, the T-gNB 154 provides the congestion information associated with a congestion status at the T-gNB 154 to the S-gNB 152. More details about the congestion information are similar as those described above with reference to FIG. 2. For the purpose of simplification, the details will be omitted. At 715, the S-gNB 152 marks or re-marks the ECN bits of forwarded data according to the congestion information of the T-gNB 154. More details about the ECN marking are similar as those described above with reference to FIG. 2. For the purpose of simplification, the details will be omitted.
According to some embodiments with reference to FIGS. 6-7, it is allowed to support ECN marking well in the handover scenario. In this way, it is possible to improve the flexibility of ECN marking and thus improve communication efficiency
FIG. 8 illustrates an example of a device 800 that supports ECN marking in accordance with aspects of the present disclosure. The device 800 may be an example of the first RAN node 201 or the second RAN node 202 as described herein. The device 800 may support wireless communication with the master RAN node 122, the secondary RAN node 124, the CU 136, the DU 138, the S-gNB 152, the T-gNB 154, and the UEs 126, 134, and 156 or any combination thereof. The device 800 may include components for bi-directional communications including components for transmitting and receiving communications, such as a processor 802, a memory 804, a transceiver 806, and, optionally, an I/O controller 808. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .
The processor 802, the memory 804, the transceiver 806, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. For example, the processor 802, the memory 804, the transceiver 806, or various combinations or components thereof may support a method for performing one or more of the operations described herein.
In some implementations, the processor 802, the memory 804, the transceiver 806, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry) . The hardware may include a processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some implementations, the processor 802 and the memory 804 coupled with the processor 802 may be configured to perform one or more of the functions described herein (e.g., executing, by the processor 802, instructions stored in the memory 804) .
For example, the processor 802 may support wireless communication at the device 800 in accordance with examples as disclosed herein. The processor 802 may be configured to operable to support a means for receiving, from a second RAN node, information associated with a congestion status at the second RAN node; and a means for performing, based on the information, ECN marking for at least one QoS flow associated with a DRB, wherein the DRB is terminated at the first RAN node. The processor 802 may be configured to operable to support a means for determining information associated with a congestion status at the second RAN node; and a means for transmitting, to a first RAN node, the information for ECN marking for at least one QoS flow associated with a DRB, wherein the DRB is terminated at the first RAN node.
The processor 802 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some implementations, the processor 802 may be configured to operate a memory array using a memory controller. In some other implementations, a memory controller may be integrated into the processor 802. The processor 802 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 804) to cause the device 800 to perform various functions of the present disclosure.
The memory 804 may include random access memory (RAM) and read-only memory (ROM) . The memory 804 may store computer-readable, computer-executable code including instructions that, when executed by the processor 802 cause the device 800 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some implementations, the code may not be directly executable by the processor 802 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some implementations, the memory 804 may include, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.
The I/O controller 808 may manage input and output signals for the device 800. The I/O controller 808 may also manage peripherals not integrated into the device M02. In some implementations, the I/O controller 808 may represent a physical connection or port to an external peripheral. In some implementations, the I/O controller 808 may utilize an operating system such as or another known operating system. In some implementations, the I/O controller 808 may be implemented as part of a processor, such as the processor 806. In some implementations, a user may interact with the device 800 via the I/O controller 808 or via hardware components controlled by the I/O controller 808.
In some implementations, the device 800 may include a single antenna 810. However, in some other implementations, the device 800 may have more than one antenna 810 (i.e., multiple antennas) , including multiple antenna panels or antenna arrays, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 806 may communicate bi-directionally, via the one or more antennas 810, wired, or wireless links as described herein. For example, the transceiver 806 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 806 may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas 810 for transmission, and to demodulate packets received from the one or more antennas 810. The transceiver 806 may include one or more transmit chains, one or more receive chains, or a combination thereof.
A transmit chain may be configured to generate and transmit signals (e.g., control information, data, packets) . The transmit chain may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM) , frequency modulation (FM) , or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM) . The transmit chain may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmit chain may also include one or more antennas 810 for transmitting the amplified signal into the air or wireless medium.
A receive chain may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receive chain may include one or more antennas 810 for receive the signal over the air or wireless medium. The receive chain may include at least one amplifier (e.g., a low-noise amplifier (LNA) ) configured to amplify the received signal. The receive chain may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receive chain may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.
FIG. 9 illustrates an example of a processor 900 that supports ECN marking in accordance with aspects of the present disclosure. The processor 900 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 900 may include a controller 902 configured to perform various operations in accordance with examples as described herein. The processor 900 may optionally include at least one memory 904, such as L1/L2/L3 cache. Additionally, or alternatively, the processor 900 may optionally include one or more arithmetic-logic units (ALUs) 900. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .
The processor 900 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., the processor 900) or other memory (e.g., random access memory (RAM) , read-only memory (ROM) , dynamic RAM (DRAM) , synchronous dynamic RAM (SDRAM) , static RAM (SRAM) , ferroelectric RAM (FeRAM) , magnetic RAM (MRAM) , resistive RAM (RRAM) , flash memory, phase change memory (PCM) , and others) .
The controller 902 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 900 to cause the processor 900 to support various operations of a base station in accordance with examples as described herein. For example, the controller 902 may operate as a control unit of the processor 900, generating control signals that manage the operation of various components of the processor 900. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.
The controller 902 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 904 and determine subsequent instruction (s) to be executed to cause the processor 900 to support various operations in accordance with examples as described herein. The controller 902 may be configured to track memory address of instructions associated with the memory 904. The controller 902 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 902 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 900 to cause the processor 900 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 902 may be configured to manage flow of data within the processor 900. The controller 902 may be configured to control transfer of data between registers, arithmetic logic units (ALUs) , and other functional units of the processor 900.
The memory 904 may include one or more caches (e.g., memory local to or included in the processor 900 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementations, the memory 904 may reside within or on a processor chipset (e.g., local to the processor 900) . In some other implementations, the memory 904 may reside external to the processor chipset (e.g., remote to the processor 900) .
The memory 904 may store computer-readable, computer-executable code including instructions that, when executed by the processor 900, cause the processor 900 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 902 and/or the processor 900 may be configured to execute computer-readable instructions stored in the memory 904 to cause the processor 900 to perform various functions. For example, the processor 900 and/or the controller 902 may be coupled with or to the memory 904, and the processor 900, the controller 902, and the memory 904 may be configured to perform various functions described herein. In some examples, the processor 900 may include multiple processors and the memory 904 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.
The one or more ALUs 900 may be configured to support various operations in accordance with examples as described herein. In some implementations, the one or more ALUs 900 may reside within or on a processor chipset (e.g., the processor 900) . In some other implementations, the one or more ALUs 900 may reside external to the processor chipset (e.g., the processor 900) . One or more ALUs 900 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 900 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 900 be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate the data according to the operation. Additionally, or alternatively, the one or more ALUs 900 may support logical operations such as AND, OR, exclusive-OR (XOR) , not-OR (NOR) , and not-AND (NAND) , enabling the one or more ALUs 900 to handle conditional operations, comparisons, and bitwise operations.
The processor 900 may support wireless communication in accordance with examples as disclosed herein. The processor 900 may be configured to or operable to support a means for receiving, from a second RAN node, information associated with a congestion status at the second RAN node; and a means for performing, based on the information, ECN marking for at least one QoS flow associated with a DRB, wherein the DRB is terminated at the first RAN node. The processor 900 may be configured to or operable to support a means for determining information associated with a congestion status at the second RAN node; and a means for transmitting, to a first RAN node, the information for ECN marking for at least one QoS flow associated with a DRB, wherein the DRB is terminated at the first RAN node.
FIG. 10 illustrates a flowchart of a method 1000 that supports ECN marking in accordance with aspects of the present disclosure. The operations of the method 1000 may be implemented by a device or its components as described herein. For example, the operations of the method 1000 may be performed by a first RAN node 201 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.
At 1010, the method may include receiving, from a second RAN node, information associated with a congestion status at the second RAN node. The operations of 1010 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1010 may be performed by the first RAN node 201 as described with reference to FIG. 2.
At 1020, the method may include perform, based on the information, explicit congestion notification (ECN) marking for at least one quality of service (QoS) flow associated with a data radio bearer (DRB) , wherein the DRB is terminated at the first RAN node. The operations of 1020 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1020 may be performed by the first RAN node 201 as described with reference to FIG. 2.
In some embodiments, the first RAN node further transmits, to the second RAN node, a request for the information. In some embodiments, the request comprises at least one of: a periodicity for the second RAN node to transmit the information; or an event to trigger the second RAN node to transmit the information. In some embodiments, the event comprises at least one of: a congestion level associated with the second RAN node being above a congestion level threshold; or a congestion ratio associated with the second RAN node being above a congestion ratio threshold.
In some embodiments, the information comprises at least one of: an indication to perform ECN marking for partial or all packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow; a suggested ratio of packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow to be ECN marked; or a congestion level associated with the second RAN node. In some embodiments, the information is comprised in a SECONDARY NODE (S-NODE) MODIFICATION REQUIRED message.
In some embodiments, the information comprises at least one of: an indication indicating whether there is congestion experienced at the second RAN node; a suggested ratio of packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow to be ECN marked; or a congestion level associated with the second RAN node. In some embodiments, the information is comprised in a general packet radio service tunneling protocol user plane (GTP-U) extension header. In some embodiments, the information is comprised in a Downlink Data Delivery Status frame.
In some embodiments, the first RAN node performs the ECN marking by: performing the ECN marking based on a congestion status at the first RAN node and the information.
In some embodiments, the first RAN node further transmits, to the second RAN node, a congestion enable indication that the ECN marking for the DRB or the at least one QoS flow is required. In some embodiments, the congestion enable indication implicitly indicates a request for the information. In some embodiments, the first RAN node comprises a master RAN node and the second RAN node comprises a secondary RAN node, the master RAN node and the secondary RAN node being served as dual connectivity for user equipment (UE) , and the DRB is master RAN node terminated SCG bearer or master RAN node terminated split bearer.
In some embodiments, the first RAN node further receives, from the second RAN node, a congestion enable indication that the ECN marking for the DRB or the at least one QoS flow is required. In some embodiments, the first RAN node comprises a secondary RAN node and the second RAN node comprises a master RAN node, the master RAN node and the secondary RAN node being served as dual connectivity for user equipment (UE) and the DRB is secondary RAN node terminated MCG bearer or secondary RAN node terminated split bearer.
In some embodiments, the congestion enable indication is comprised in an S-NODE ADDITION REQUEST message or an S-NODE MODIFICATION REQUEST message.
In some embodiments, the first RAN node comprises a centralized unit (CU) of a base station (BS) , and the second RAN node comprises a distributed unit (DU) of the BS. In some embodiments, the CU comprises a control plane (CP) and a user plane (UP) , and the information is received by the CP of the CU from the DU, and the information is forwarded by the CP of the CU to the UP of the CU, and the ECN marking is performed by the UP of the CU.
FIG. 11 illustrates a flowchart of a method 1100 that supports ECN marking in accordance with aspects of the present disclosure. The operations of the method 1100 may be implemented by a device or its components as described herein. For example, the operations of the method 1100 may be performed by a second RAN node 202 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.
At 1110, the method may include determining information associated with a congestion status at the second RAN node. The operations of 1110 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1110 may be performed by the second RAN node 202 as described with reference to FIG. 2.
At 1120, the method may include transmitting, to a first RAN node, the information for explicit congestion notification (ECN) marking for at least one quality of service (QoS) flow associated with a data radio bearer (DRB) , wherein the DRB is terminated at the first RAN node. The operations of 1120 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1120 may be performed by the second RAN node 202 as described with reference to FIG. 2.
In some embodiments, the second RAN node further receives, from the first RAN node, a request for the information. In some embodiments, the request comprises at least one of: a periodicity for the second RAN node to transmit the information; or an event to trigger the second RAN node to transmit the information. In some embodiments, the event comprises at least one of: a congestion level associated with the second RAN node being above a congestion level threshold; or a congestion ratio associated with the second RAN node being above a congestion ratio threshold.
In some embodiments, the information comprises at least one of: an indication to perform ECN marking for partial or all packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow; a suggested ratio of packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow to be ECN marked; or a congestion level associated with the second RAN node. In some embodiments, the information is comprised in a SECONDARY NODE (S-NODE) MODIFICATION REQUIRED message.
In some embodiments, the information comprises at least one of: an indication indicating whether there is congestion experienced at the second RAN node; a suggested ratio of packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow to be ECN marked; or a congestion level associated with the second RAN node. In some embodiments, the information is comprised in a general packet radio service tunneling protocol user plane (GTP-U) extension header. In some embodiments, the information is comprised in a Downlink Data Delivery Status frame.
In some embodiments, the second RAN node further receives, from the first RAN node, a congestion enable indication that the ECN marking for the DRB or the at least one QoS flow is required. In some embodiments, the congestion enable indication implicitly indicates a request for the information. In some embodiments, the first RAN node comprises a master RAN node and the second RAN node comprises a secondary RAN node, the master RAN node and the secondary RAN node being served as dual connectivity for user equipment (UE) , and the DRB is master RAN node terminated SCG bearer or master RAN node terminated split bearer.
In some embodiments, the second RAN node further transmits, to the first RAN node, an indication that the ECN marking for the DRB or the at least one QoS flow is required. In some embodiments, the first RAN node comprises a secondary RAN node and the second RAN node comprises a master RAN node, the master RAN node and the secondary RAN node being served as dual connectivity for user equipment (UE) and the DRB is secondary RAN node terminated MCG bearer or secondary RAN node terminated split bearer.
In some embodiments, the indication is comprised in an S-NODE ADDITION REQUEST message or an S-NODE MODIFICATION REQUEST message.
In some embodiments, the first RAN node comprises a centralized unit (CU) of a base station (BS) , and the second RAN node comprises a distributed unit (DU) of the BS. In some embodiments, the CU comprises a control plane (CP) and a user plane (UP) , and the information is received by the CP of the CU from the DU, and the information is forwarded by the CP of the CU to the UP of the CU, and the ECN marking is performed by the UP of the CU.
It should be noted that the methods described herein describes possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined.
The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.
Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer. By way of example, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor.
As used herein, including in the claims, an article “a” before an element is unrestricted and understood to refer to “at least one” of those elements or “one or more” of those elements. The terms “a, ” “at least one, ” “one or more, ” and “at least one of one or more” may be interchangeable. As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” or “one or both of” ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. Further, as used herein, including in the claims, a “set” may include one or more elements.
The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.
In summary, embodiments of the present disclosure may provide the following solutions.
Clause 1. A first radio access network (RAN) node comprising: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the first RAN node to: receive, from a second RAN node, information associated with a congestion status at the second RAN node; and perform, based on the information, explicit congestion notification (ECN) marking for at least one quality of service (QoS) flow associated with a data radio bearer (DRB) , wherein the DRB is terminated at the first RAN node.
Clause 2. The first RAN node of clause 1, wherein the at least one processor is further configured to cause the first RAN node to: transmit, to the second RAN node, a request for the information.
Clause 3. The first RAN node of clause 2, wherein the request comprises at least one of: a periodicity for the second RAN node to transmit the information; or an event to trigger the second RAN node to transmit the information.
Clause 4. The first RAN node of clause 3, wherein the event comprises at least one of: a congestion level associated with the second RAN node being above a congestion level threshold; or a congestion ratio associated with the second RAN node being above a congestion ratio threshold.
Clause 5. The first RAN node of clause 1, wherein the information comprises at least one of: an indication to perform ECN marking for partial or all packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow; a suggested ratio of packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow to be ECN marked; or a congestion level associated with the second RAN node.
Clause 6. The first RAN node of clause 5, wherein the information is comprised in a SECONDARY NODE (S-NODE) MODIFICATION REQUIRED message.
Clause 7. The first RAN node of clause 1, wherein the information comprises at least one of: an indication indicating whether there is congestion experienced at the second RAN node; a suggested ratio of packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow to be ECN marked; or a congestion level associated with the second RAN node.
Clause 8. The first RAN node of clause 7, wherein the information is comprised in a general packet radio service tunneling protocol user plane (GTP-U) extension header.
Clause 9. The first RAN node of clause 8, wherein the information is comprised in a Downlink Data Delivery Status frame.
Clause 10. The first RAN node of clause 1, wherein the at least one processor is configured to cause the first RAN node to perform the ECN marking by: performing the ECN marking based on a congestion status at the first RAN node and the information.
Clause 11. The first RAN node of clause 1, wherein the at least one processor is further configured to cause the first RAN node to: transmit, to the second RAN node, a congestion enable indication that the ECN marking for the DRB or the at least one QoS flow is required.
Clause 12. The first RAN node of clause 11, wherein the congestion enable indication implicitly indicates a request for the information.
Clause 13. The first RAN node of clause 11, wherein the first RAN node comprises a master RAN node and the second RAN node comprises a secondary RAN node, the master RAN node and the secondary RAN node being served as dual connectivity for user equipment (UE) , and the DRB is master RAN node terminated secondary cell group (SCG) bearer or master RAN node terminated split bearer.
Clause 14. The first RAN node of clause 1, wherein the at least one processor is further configured to cause the first RAN node to: receive, from the second RAN node, a congestion enable indication that the ECN marking for the DRB or the at least one QoS flow is required.
Clause 15. The first RAN node of clause 14, wherein the first RAN node comprises a secondary RAN node and the second RAN node comprises a master RAN node, the master RAN node and the secondary RAN node being served as dual connectivity for user equipment (UE) and the DRB is secondary RAN node terminated master cell group (MCG) bearer or secondary RAN node terminated split bearer.
Clause 16. The first RAN node of clause 13 or 15, wherein the congestion enable indication is comprised in an S-NODE ADDITION REQUEST message or an S-NODE MODIFICATION REQUEST message.
Clause 17. The first RAN node of clause 1, wherein the first RAN node comprises a centralized unit (CU) of a base station (BS) , and the second RAN node comprises a distributed unit (DU) of the BS.
Clause 18. The first RAN node of clause 17, wherein the CU comprises a control plane (CP) and a user plane (UP) , and the information is received by the CP of the CU from the DU, and the information is forwarded by the CP of the CU to the UP of the CU, and the ECN marking is performed by the UP of the CU.
Clause 19. A second radio access network (RAN) node comprising: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the second RAN node to: determine information associated with a congestion status at the second RAN node; and transmit, to a first RAN node, the information for explicit congestion notification (ECN) marking for at least one quality of service (QoS) flow associated with a data radio bearer (DRB) , wherein the DRB is terminated at the first RAN node.
Clause 20. The second RAN node of clause 19, wherein the at least one processor is further configured to cause the second RAN node to: receive, from the first RAN node, a request for the information.
Clause 21. The second RAN node of clause 20, wherein the request comprises at least one of: a periodicity for the second RAN node to transmit the information; or an event to trigger the second RAN node to transmit the information.
Clause 22. The second RAN node of clause 21, wherein the event comprises at least one of: a congestion level associated with the second RAN node being above a congestion level threshold; or a congestion ratio associated with the second RAN node being above a congestion ratio threshold.
Clause 23. The second RAN node of clause 19, wherein the information comprises at least one of: an indication to perform ECN marking for partial or all packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow; a suggested ratio of packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow to be ECN marked; or a congestion level associated with the second RAN node.
Clause 24. The second RAN node of clause 23, wherein the information is comprised in a SECONDARY NODE (S-NODE) MODIFICATION REQUIRED message.
Clause 25. The second RAN node of clause 19, wherein the information comprises at least one of: an indication indicating whether there is congestion experienced at the second RAN node; a suggested ratio of packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow to be ECN marked; or a congestion level associated with the second RAN node.
Clause 26. The second RAN node of clause 25, wherein the information is comprised in a general packet radio service tunneling protocol user plane (GTP-U) extension header.
Clause 27. The second RAN node of clause 26, wherein the information is comprised in a Downlink Data Delivery Status frame.
Clause 28. The second RAN node of clause 19, wherein the at least one processor is further configured to cause the second RAN node to: receive, from the first RAN node, a congestion enable indication that the ECN marking for the DRB or the at least one QoS flow is required.
Clause 29. The second RAN node of clause 28, wherein the congestion enable indication implicitly indicates a request for the information.
Clause 30. The second RAN node of clause 28, wherein the first RAN node comprises a master RAN node and the second RAN node comprises a secondary RAN node, the master RAN node and the secondary RAN node being served as dual connectivity for user equipment (UE) , and the DRB is master RAN node terminated secondary cell group (SCG) bearer or master RAN node terminated split bearer.
Clause 31. The second RAN node of clause 19, wherein the at least one processor is further configured to cause the second RAN node to: transmit, to the first RAN node, an indication that the ECN marking for the DRB or the at least one QoS flow is required.
Clause 32. The second RAN node of clause 31, wherein the first RAN node comprises a secondary RAN node and the second RAN node comprises a master RAN node, the master RAN node and the secondary RAN node being served as dual connectivity for user equipment (UE) and the DRB is secondary RAN node terminated master cell group (MCG) bearer or secondary RAN node terminated split bearer.
Clause 33. The second RAN node of clause 30 or 32, wherein the indication is comprised in an S-NODE ADDITION REQUEST message or an S-NODE MODIFICATION REQUEST message.
Clause 34. The second RAN node of clause 19, wherein the first RAN node comprises a centralized unit (CU) of a base station (BS) , and the second RAN node comprises a distributed unit (DU) of the BS.
Clause 35. The second RAN node of clause 34, wherein the CU comprises a control plane (CP) and a user plane (UP) , and the information is received by the CP of the CU from the DU, and the information is forwarded by the CP of the CU to the UP of the CU, and the ECN marking is performed by the UP of the CU.
Clause 36. A method performed by a first radio access network (RAN) node, comprising: receiving, from a second RAN node, information associated with a congestion status at the second RAN node; and performing, based on the information, explicit congestion notification (ECN) marking for at least one quality of service (QoS) flow associated with a data radio bearer (DRB) , wherein the DRB is terminated at the first RAN node.
Clause 37. A method performed by a second radio access network (RAN) node, comprising: determining information associated with a congestion status at the second RAN node; and transmitting, to a first RAN node, the information for explicit congestion notification (ECN) marking for at least one quality of service (QoS) flow associated with a data radio bearer (DRB) , wherein the DRB is terminated at the first RAN node.

Claims

A first radio access network (RAN) node comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the first RAN node to:

receive, from a second RAN node, information associated with a congestion status at the second RAN node; and

perform, based on the information, explicit congestion notification (ECN) marking for at least one quality of service (QoS) flow associated with a data radio bearer (DRB) , wherein the DRB is terminated at the first RAN node.
The first RAN node of claim 1, wherein the information comprises at least one of:

an indication to perform ECN marking for partial or all packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow;

a suggested ratio of packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow to be ECN marked; or

a congestion level associated with the second RAN node.
The first RAN node of claim 2, wherein the information is comprised in a SECONDARY NODE (S-NODE) MODIFICATION REQUIRED message.
The first RAN node of claim 1, wherein the information comprises at least one of:

an indication indicating whether there is congestion experienced at the second RAN node;

a suggested ratio of packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow to be ECN marked; or

a congestion level associated with the second RAN node.
The first RAN node of claim 4, wherein the information is comprised in a general packet radio service tunneling protocol user plane (GTP-U) extension header.
The first RAN node of claim 1, wherein the at least one processor is configured to cause the first RAN node to perform the ECN marking by:

performing the ECN marking based on a congestion status at the first RAN node and the information.
The first RAN node of claim 1, wherein the at least one processor is further configured to cause the first RAN node to:

transmit, to the second RAN node, a congestion enable indication that the ECN marking for the DRB or the at least one QoS flow is required.
The first RAN node of claim 7, wherein the first RAN node comprises a master RAN node and the second RAN node comprises a secondary RAN node, the master RAN node and the secondary RAN node being served as dual connectivity for user equipment (UE) , and the DRB is master RAN node terminated secondary cell group (SCG) bearer or master RAN node terminated split bearer.
The first RAN node of claim 1, wherein the at least one processor is further configured to cause the first RAN node to:

receive, from the second RAN node, a congestion enable indication that the ECN marking for the DRB or the at least one QoS flow is required.
The first RAN node of claim 9, wherein the first RAN node comprises a secondary RAN node and the second RAN node comprises a master RAN node, the master RAN node and the secondary RAN node being served as dual connectivity for user equipment (UE) and the DRB is secondary RAN node terminated master cell group (MCG) bearer or secondary RAN node terminated split bearer.
The first RAN node of claim 1, wherein the first RAN node comprises a centralized unit (CU) of a base station (BS) , and the second RAN node comprises a distributed unit (DU) of the BS.
The first RAN node of claim 11 wherein the CU comprises a control plane (CP) and a user plane (UP) , and the information is received by the CP of the CU from the DU, and the information is forwarded by the CP of the CU to the UP of the CU, and the ECN marking is performed by the UP of the CU.
A second radio access network (RAN) node comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the second RAN node to:

determine information associated with a congestion status at the second RAN node; and

transmit, to a first RAN node, the information for explicit congestion notification (ECN) marking for at least one quality of service (QoS) flow associated with a data radio bearer (DRB) , wherein the DRB is terminated at the first RAN node.
The second RAN node of claim 13, wherein the information comprises at least one of:

an indication to perform ECN marking for partial or all packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow;

a suggested ratio of packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow to be ECN marked; or

a congestion level associated with the second RAN node.
The second RAN node of claim 14, wherein the information is comprised in a SECONDARY NODE (S-NODE) MODIFICATION REQUIRED message.
The second RAN node of claim 13, wherein the information comprises at least one of:

an indication indicating whether there is congestion experienced at the second RAN node;

a suggested ratio of packets received from or to be transmitted to the second RAN node of the DRB or the at least one QoS flow to be ECN marked; or

a congestion level associated with the second RAN node.
The second RAN node of claim 16, wherein the information is comprised in a general packet radio service tunneling protocol user plane (GTP-U) extension header.
The second RAN node of claim 13, wherein the first RAN node comprises a centralized unit (CU) of a base station (BS) , and the second RAN node comprises a distributed unit (DU) of the BS.
A method performed by a first radio access network (RAN) node, comprising:

receiving, from a second RAN node, information associated with a congestion status at the second RAN node; and

performing, based on the information, explicit congestion notification (ECN) marking for at least one quality of service (QoS) flow associated with a data radio bearer (DRB) , wherein the DRB is terminated at the first RAN node.
A method performed by a second radio access network (RAN) node, comprising:

determining information associated with a congestion status at the second RAN node; and

transmitting, to a first RAN node, the information for explicit congestion notification (ECN) marking for at least one quality of service (QoS) flow associated with a data radio bearer (DRB) , wherein the DRB is terminated at the first RAN node.