Patent Description:
The disclosed embodiments relate generally to wireless communication, and, more particularly, to method of enhanced handling on Quality of Service (QoS) flow description in <NUM> new radio (NR) systems.

The wireless communications network has grown exponentially over the years. A Long-Term Evolution (LTE) system offers high peak data rates, low latency, improved system capacity, and low operating cost resulting from simplified network architecture. LTE systems, also known as the <NUM> system, also provide seamless integration to older wireless network, such as GSM, CDMA and Universal Mobile Telecommunication System (UMTS). In LTE systems, an evolved universal terrestrial radio access network (E-UTRAN) includes a plurality of evolved Node-Bs (eNodeBs or eNBs) communicating with a plurality of mobile stations, referred to as user equipments (UEs). The <NUM>rd generation partner project (3GPP) network normally includes a hybrid of <NUM>/<NUM>/<NUM> systems. The Next Generation Mobile Network (NGMN) board, has decided to focus the future NGMN activities on defining the end-to-end requirements for <NUM> new radio (NR) systems.

In <NUM>, a Protocol Data Unit (PDU) session establishment is a parallel procedure of a Packet Data Network (PDN) connection procedure in <NUM>. A PDU session defines the association between the UE and the data network that provides a PDU connectivity service. Each PDU session is identified by a PDU session ID, and may include multiple QoS flows and QoS rules. In <NUM> network, QoS flow is the finest granularity for QoS management to enable more flexible QoS control. The concept of QoS flow in <NUM> is like EPS bearer in <NUM>. Each QoS flow is identified by a QoS flow ID (QFI) which is unique within a PDU session. Each QoS rule is identified by a QoS rule ID (QRI). There can be more than one QoS rule associated with the same QoS flow. A default QoS rule is required to be sent to the UE for every PDU session establishment and it is associated with a QoS flow. Within a PDU session, there should be one and only one default QoS rule.

Quality of Service (QoS) indicates the performance from the perspective of network users. All types of traffic mapped to the same LTE EPS bearer or to the same <NUM> QoS flow receive the same level of packet forwarding treatment (e.g., scheduling policy, queue management policy, rate shaping policy, RLC configuration etc.) Providing different QoS forwarding treatment requires separate <NUM> QoS flow. Each QoS flow may include multiple QoS rules consisting of QoS profile, packet filters, and precedence order. QoS profile includes QoS parameters and QoS marking. Packet filter is used for binding a QoS flow to a specific QoS marking. Precedence order represents the priority to adapt a QoS rule to a QoS flow. UE performs the classification and marking of uplink (UL) User Plane traffic, i.e., the association of UL traffic to QoS flows based on QoS rules.

The QoS flow parameters, provisioned by the network via QoS Flow Description IE, are separated from the QoS rule IE. When the network configures a QoS rule of a QFI, the network may not provide the corresponding QoS flow description. A solution is sought for UE to handle such QoS rule configuration without providing corresponding QoS flow description.

3GPP document C1-<NUM> discusses how to handle errors due to missing QoS flow description parameters for GBR QoS flows.

A method of QoS rule management with enhanced handling on QoS flow description is proposed. UE checks QoS configuration received from the network for QoS operation errors. When UE receives a QoS rule associated with a specific QFI but has no QoS flow description for the QFI, UE further determines whether the QoS rule is of a GBR QoS flow. If so, UE detects a QoS operation error. If the QoS rule is the default QoS rule, then UE releases the PDU session. If the QoS rule is not the default QoS rule, then UE either rejects a PDU session modification command that carries the QoS rule or deletes the QoS rule carried by a PDU session establishment accept with a 5GSM cause value indicating the QoS operation error.

In one embodiment, a UE receives a Protocol data unit (PDU) session modification command message for performing the QoS operation associated with a PDU session based at least on one of a QoS rules information element (IE) and a QoS flow descriptions IE in the mobile communication network. According to the invention the UE determines that a QoS rule associated with a QoS flow having a specific QoS flow ID (QFI) has no corresponding QoS flow description, wherein the specific QFI indicates a guaranteed bit rate (GBR) QoS flow. The UE deletes the QoS rule after completing the QoS operation if the QoS rules IE contains another valid QoS rule, or rejecting the PDU session modification command message if the QoS rules IE does not contain another valid QoS rule, wherein the QoS rule is not a default QoS rule.

In another embodiment, the UE receives a Protocol data unit (PDU) session establishment accept message for performing a Quality of Service (QoS) operation associated with a PDU session based at least on one of a QoS rules information element (IE) and a QoS flow descriptions IE in a mobile communication network. The UE determines that a QoS rule associated with a QoS flow having a specific QoS flow ID (QFI) has no corresponding QoS flow description after the QoS operation. The UE determines that the QoS flow having the specific QFI has a guaranteed bit rate (GBR) QoS flow resource type. The UE deletes the QoS rule if the QoS rule is not a default QoS rule or releases the PDU session if the QoS rule is the default QoS rule.

Other embodiments and advantages are described in the detailed description below. This summary does not purport to define the invention.

The accompanying drawings, where like numerals indicate like components, illustrate embodiments of the disclosure,.

<FIG> illustrates an exemplary <NUM> network100 supporting Quality of Service (QoS) rule management in accordance with one novel aspect. <NUM> new radio (NR) network <NUM> comprises a user equipment UE <NUM>, a base station gNB <NUM>, an access and mobility management function (AMF) <NUM>, and a <NUM> core network 5GC <NUM>. In the example of <FIG>, UE <NUM> and its serving base station gNB <NUM> belong to part of a radio access network RAN <NUM>. In Access Stratum (AS) layer, RAN <NUM> provides radio access for UE <NUM> via a radio access technology (RAT). In Non-Access Stratum (NAS) layer, AMF 103communicates with gNB <NUM> and 5GC <NUM> for access and mobility management of wireless access devices in <NUM> network <NUM>. UE <NUM> may be equipped with a radio frequency (RF) transceiver or multiple RF transceivers for different application services via different RATs/CNs. UE <NUM> may be a smart phone, a wearable device, an Internet of Things (IoT) device, and a tablet, etc..

5GSnetworks are packet-switched (PS) Internet Protocol (IP) networks. This means that the networks deliver all data traffic in IP packets, and provide users with Always-On IP Connectivity. When UE joins a5GS network, a Packet Data Network (PDN) address (i.e., the one that can be used on the PDN) is assigned to the UE for its connection to the PDN. In <NUM>,EPS has defined a Default EPS Bearer to provide the IP Connectivity that is Always-On. In <NUM>, a Protocol Data Unit (PDU) session establishment procedure is a parallel procedure of a PDN connection procedure in <NUM>. A PDU session defines the association between the UE and the data network that provides a PDU connectivity service. Each PDU session is identified by a PDU session ID, and may include multiple QoS flows and QoS rules. In <NUM> network, QoS flow is the finest granularity for QoS management to enable more flexible QoS control. The concept of QoS flow in <NUM> is like EPS bearer in <NUM>. Each QoS flow is identified by a QoS flow ID (QFI) which is unique within a PDU session. Each QoS rule is identified by a QoS rule ID (QRI). There can be more than one QoS rule associated with the same QoS flow. A default QoS rule is required to be sent to the UE for every PDU session establishment and it is associated with a QoS flow.

In the example of <FIG>, UE <NUM> establishes a PDU session <NUM>, which includes multiple QoS flows and QoS rules in Non-Access Stratum (NAS) layer. Each QoS flow needs to be supported by a mapping Data Radio Bearer (DRB) in Access Stratum (AS) layer. Multiple QoS flows can be mapped to the same DRB. For example, QoS flows #<NUM> and #<NUM> are mapped to DRB #<NUM>, and QoS flow #<NUM> is mapped to DRB #<NUM>. If there is a default DRB for a PDU session, then all traffic of QoS flows that have no mapping DRBs are sent via the default DRB. In the current <NUM> NAS specification, based on QoS operation codes defined in the QoS rule IE and QoS flow description IE, the allowed different QoS operations includes to create, modify, and delete QoS rule and QoS flow description via PDU session establishment and modification procedures. The QoS flow parameters, however, provisioned by the network via QoS flow description IE, are separated from the QoS rule IE. As a result, when the network configures a QoS rule having a QFI, the network may not provide the corresponding QoS flow description for the QFI. In addition, the QoS rule may be of a guaranteed bit rate (GBR) QoS flow, which requires QoS flow parameters for data transmission and reception. It is not clear how UE should handle such scenario.

In accordance with one novel aspect, UE behavior and error handling are defined for QoS rule operations via PDU session establishment and modification procedures. The default QoS rule indication (DQR) and the QoS flow identifier (QFI) of a signaled QoS rule should not be changed. The UE should check the QoS configuration (<NUM>) provided in the PDU session modification command message and in the PDU session establishment accept message for QoS operation errors. In one example, when UE <NUM> receives a QoS rule associated with a specific QFI but has no QoS flow description for the QFI, in addition, UE <NUM> determines that the QoS rule is of a GBR QoS flow, then UE <NUM> detects a QoS operation error. If the QoS rule is the default QoS rule, then UE <NUM> releases the PDU session. If the QoS rule is not the default QoS rule, then UE <NUM> either rejects a PDU session modification command that carries the QoS rule or deletes the QoS rule carried by a PDU session modification request with a 5GSM cause value indicating the QoS operation error.

<FIG> illustrates simplified block diagrams of wireless devices, e.g., a UE <NUM> and network entity <NUM> in accordance with embodiments of the current invention. Network entity <NUM> may be a base station combined with an MME or AMF. Network entity <NUM> has an antenna <NUM>, which transmits and receives radio signals. A radio frequency RF transceiver module <NUM>, coupled with the antenna, receives RF signals from antenna <NUM>, converts them to baseband signals and sends them to processor <NUM>. RF transceiver <NUM> also converts received baseband signals from processor <NUM>, converts them to RF signals, and sends out to antenna <NUM>. Processor <NUM> processes the received baseband signals and invokes different functional modules to perform features in base station <NUM>. Memory <NUM> stores program instructions and data <NUM> to control the operations of base station <NUM>. In the example of <FIG>, network entity <NUM> also includes protocol stack <NUM> and a set of control functional modules and circuit <NUM>. PDU session handling circuit <NUM> handles PDU session establishment and modification procedures. QoS flow and rule management circuit <NUM> creates, modifies, and deletes QoS flows and QoS rules for UE. Configuration and control circuit <NUM> provides different parameters to configure and control UE of related functionalities including mobility management and session management.

Similarly, UE <NUM> has memory <NUM>, a processor <NUM>, and radio frequency (RF) transceiver module <NUM>. RF transceiver <NUM> is coupled with antenna <NUM>, receives RF signals from antenna <NUM>, converts them to baseband signals, and sends them to processor <NUM>. RF transceiver <NUM> also converts received baseband signals from processor <NUM>, converts them to RF signals, and sends out to antenna <NUM>. Processor <NUM> processes the received baseband signals and invokes different functional modules and circuits to perform features in UE <NUM>. Memory <NUM> stores data and program instructions <NUM> to be executed by the processor to control the operations of UE <NUM>. Suitable processors include, by way of example, a special purpose processor, a digital signal processor (DSP), a plurality of micro-processors, one or more micro-processor associated with a DSP core, a controller, a microcontroller, application specific integrated circuits (ASICs), file programmable gate array (FPGA) circuits, and other type of integrated circuits (ICs), and/or state machines. A processor in associated with software may be used to implement and configure features of UE <NUM>.

UE <NUM> also comprises a set of functional modules and control circuits to carry out functional tasks of UE <NUM>. Protocol stacks <NUM> comprise Non-Access-Stratum (NAS) layer to communicate with an AMF entity connecting to the core network, Radio Resource Control (RRC) layer for high layer configuration and control, Packet Data Convergence Protocol/Radio Link Control (PDCP/RLC) layer, Media Access Control (MAC) layer, and Physical (PHY) layer. System modules and circuits <NUM> may be implemented and configured by software, firmware, hardware, and/or combination thereof. The function modules and circuits, when executed by the processors via program instructions contained in the memory, interwork with each other to allow UE <NUM> to perform embodiments and functional tasks and features in the network. In one example, system modules and circuits <NUM> comprise PDU session handling circuit <NUM> that performs PDU session establishment and modification procedures with the network, a QoS flow and rule management circuit <NUM> that manages, creates, modifies, and deletes QoS flows and QoS rules, a config and control circuit <NUM> that handles configuration and control parameters for mobility management and session management.

<FIG> illustrates one embodiment of a QoS rule comprising a QoS rule identifier (QRI) and a QoS flow identifier (QFI). The network can provide a QoS rule IE to the UE, which comprises a list of QoS rules. Each QoS rule, as depicted by <FIG>, comprises a QoS rule identifier (QRI), a length of the QoS rule, a rule operation code, a default QoS rule (DQR) bit, a number of packet filters, a packet filter list, a QoS rule precedence, and a QoS flow identifier (QFI). Since QFI identifies a corresponding QoS flow, the QoS rule having the specific QFI is thus associated with the QoS flow through the same specific QFI.

<FIG> illustrates one embodiment of a QoS flow description identified by a QFI. The network can provide a QoS flow description IE to the UE, which comprises a list of QoS flow descriptions. Each QoS flow description, as depicted by <FIG>, comprises a QFI, a QoS flow operation code, a number of QoS flow parameters, and a QoS flow parameter list. As defined by the 3GPP specification, a parameter identifier field is used to identify each parameter included in the parameter list and it contains the hexadecimal coding of the parameter identifier. For example, the following parameter identifiers are specified: <NUM>(5QI), <NUM>(GFBR uplink), <NUM>(GFBR downlink), <NUM>(MFBR uplink), <NUM>(MFBR downlink), <NUM>(averaging window), <NUM>(EPS bearer identity). The 3GPP specification also defines the standardized 5QI to QoS characteristics mapping, e.g., which 5QI is mapped to GBR resource type, and which 5QI is mapped to non-GBR resource type.

<FIG> illustrates a one embodiment of PDU session modification procedure with enhanced QoS flow description handling in accordance with one novel aspect. In step <NUM>, UE <NUM> and network <NUM> establish a PDU session via a PDU session establishment procedure. The PDU session may be established to comprise one or more QoS rules, including one default QoS rule. Each QoS rule is associated with a QoS flow identified by a QFI. In step <NUM>, network <NUM> sends a PDU session modification command message to UE <NUM>. The command message is for UE to perform certain QoS operations for the PDU session, for example, to create a new QoS rule or new QoS flow description, and/or to modify an existing QoS rule or existing QoS flow description. The command message carries a QoS rule IE and/or QoS flow description IE for such QoS operations. In step <NUM>, UE <NUM> determines whether the QoS operation would result in the existing, to-be-created or to-be-modified QoS rule to have empty QoS flow description.

QoS rule having empty QoS flow description can happen under different QoS operations. First, if the QoS operation is to create a new QoS rule having a specific QFI but the network does not provide corresponding QoS flow description for the specific QFI, then the to-be-created QoS rule will have empty QoS flow description. Second, if the QoS operation is to delete existing QoS flow description of a QFI, then such deletion can result in the QoS rule associated to the QFI to have empty QoS flow description. Third, if the QoS operation is to modify existing QoS rule by changing to a new QFI, then the QoS rule associated to the new QFI will have no QoS flow description.

In step <NUM>, UE 501checks whether the existing, to-be-created or to-be-modified QoS rule is of a GBR QoS flow. If so, then a QoS operation error occurs, because the QoS rule should not have an empty QoS flow description for GBR QoS flow. In order for UE to properly control traffic flow under a GBR QoS flow, the UE needs to know the detailed QoS flow parameters such as GFBR and MFBR for the uplink and for the downlink. As a result, it is an error for GBR QoS flow to not be configured with QoS flow description. UE can make the determination under different scenarios. In a first example, a GBR QoS flow can use 5QI as QFI in the description part of a QoS flow. Since 5QI value is mapped to QoS characteristics including GBR or non-GBR resource type, UE thus can determine whether a QoS rule is of a GBR or non-GBR QoS flow. In another example, the QoS rule is provided together with a QoS flow description that indicates it is a GBR QoS flow. However, the QoS flow description is to be deleted, and UE thus is able to determine that the QoS rule is of a GBR QoS flow but with no QoS flow description.

In step <NUM>, UE <NUM> further detects whether the existing, to-be-created or to-be-modified QoS rule is default QoS rule. If the detecting result in step <NUM> is positive, that means the QoS rule is a default QoS rule, then such syntactical error causes problem with the default QoS rule of the PDU session. As a result, the PDU session should be released. In step <NUM>, UE <NUM> initiates a PDU session release procedure by sending a PDU session release request message to network <NUM>. The request message carries a 5GSM cause value #84indicating "syntactical error in the QoS operation". If the detecting result is negative in step <NUM>, that means the QoS rule is not a default QoS rule. Then in step <NUM>, UE <NUM> rejects the PDU session modification command message with the 5GSM cause value #<NUM> indicating "syntactical error in the QoS operation" if the QoS rules IE contains no other QoS rule. On the other hand, if the QoS rules IE contains other QoS, then in step <NUM>, UE <NUM> shall delete the corresponding QoS rule which has no corresponding QoS flow description by initiating a PDU session modification procedure after the completion of the current PDU session modification procedure.

<FIG> illustrates a one embodiment of PDU session establishment procedure with enhanced QoS flow description handling in accordance with one novel aspect. In step <NUM>, UE <NUM> sends a PDU session establishment request message to network <NUM>. In step <NUM>, network <NUM> sends a PDU session establishment accept message to UE <NUM>. The accept message carries a QoS rule IE and/or QoS flow description IE for the UE to create new QoS rules and QoS flow descriptions. In step <NUM>, UE <NUM> determines whether the QoS operation would result in the to-be-created QoS rule to have empty QoS flow description. In step <NUM>, UE <NUM> checks whether the to-be-created QoS rule is of a GBR QoS flow resource type. If so, then a QoS operation error occurs, because the QoS rule should not have an empty QoS flow description for GBR QoS flow.

In step <NUM>, UE <NUM> further detects whether the to-be-created QoS rule is a default QoS rule. If the detecting result in step <NUM> is positive, that means the QoS rule is a default QoS rule, then such syntactical error causes problem with the default QoS rule of the PDU session. As a result, the PDU session should be released. In step <NUM>, UE <NUM> initiates a PDU session release procedure by sending a PDU session release request message to network <NUM>. The request message carries a 5GSM cause value #<NUM> indicating "syntactical error in the QoS operation". If the detecting result is negative in step <NUM>, that means the QoS rule is not a default QoS rule. Then in step <NUM>, UE <NUM> deletes the QoS rule by sending a PDU session modification request message to network <NUM> with the 5GSM cause value #<NUM> indicating "syntactical error in the QoS operation".

<FIG> is a flow chart of a method of QoS flow description handling for PDU session modification procedure in accordance with one novel aspect of the present invention. In step <NUM>, a UE receives a Protocol data unit (PDU) session modification command message for performing the QoS operation associated with a PDU session based at least on one of a QoS rules information element (IE) and a QoS flow descriptions IE in the mobile communication network. In step <NUM>, the UE determines that a QoS rule associated with a QoS flow having a specific QoS flow ID (QFI) has no corresponding QoS flow description, wherein the specific QFI indicates a guaranteed bit rate (GBR) QoS flow. In step <NUM>, the UE deletes the QoS rule after completing the QoS operation if the QoS rules IE contains another valid QoS rule, or rejecting the PDU session modification command message if the QoS rules IE does not contain another valid QoS rule, wherein the QoS rule is not a default QoS rule.

<FIG> is a flow chart of a method of QoS flow description handling for PDU session establishment procedure in accordance with one novel aspect of the present invention. In step <NUM>, the UE receives a Protocol data unit (PDU) session establishment accept message for performing a Quality of Service (QoS) operation associated with a PDU session based at least on one of a QoS rules information element (IE) and a QoS flow descriptions IE in a mobile communication network. In step <NUM>, the UE determines that a QoS rule associated with a QoS flow having a specific QoS flow ID (QFI) has no corresponding QoS flow description after the QoS operation. In step <NUM>, the UE determines that the QoS flow having the specific QFI has a guaranteed bit rate (GBR) QoS flow resource type. In step <NUM>, the UE deletes the QoS rule if the QoS rule is not a default QoS rule or releases the PDU session if the QoS rule is the default QoS rule.

Claim 1:
A method of performing a Quality of Service, in the following also referred to as QoS, Operation in a mobile communication network, comprising:
receiving a Protocol data unit, in the following also referred to as PDU, session modification command message by a user equipment, in the following also referred to as UE, for performing the QoS operation associated with a PDU session based at least on one of a QoS rules information element, in the following also referred to as IE, and a QoS flow descriptions IE in the mobile communication network (<NUM>);
determining that a QoS rule associated with a QoS flow having a specific QoS flow ID, in the following also referred to as QFI, has no corresponding QoS flow description (<NUM>); and
deleting the QoS rule after completing the QoS operation if the QoS rules IE contains another valid QoS rule, or rejecting the PDU session modification command message if the QoS rules IE does not contain another valid QoS rule, wherein the QoS rule is not a default QoS rule (<NUM>),
characterized in that
the specific QFI indicates a guaranteed bit rate, in the following also referred to as GBR, QoS flow.