The disclosure relates to wireless communication technology, and more particularly to a method of a wireless communication system for enhancing quality of service (QoS).
5G New Radio (NR) is a recently developed radio access technology that supports high throughput and low latency as well as large capacity communications. For industrial applications adopting 5G NR technology, such as man-machine coexistence, automated production, and so on, different connection recovery times are required when a connection error occurs. In particular, some applications (e.g. motion control and on board control) in automation technology require shorter connection recovery times. Therefore, how to quickly recover connections for certain specific applications has become an important issue to ensure normal operations for the industrial applications.
The disclosure directs to a method for providing quality of service (QoS) in a wireless communication system. The method includes: triggering a service reliability procedure in response to a first network condition; and determining whether to perform a protocol layer QoS handling mechanism or a physical layer QoS handling mechanism to enhance QoS between a network and a mobile terminal depending on a QoS requirement.
In accordance with one or more embodiments of the disclosure, performing the protocol layer QoS handling mechanism includes: activating, at the mobile terminal, a radio link control (RLC) entity for a packet data convergence protocol (PDCP) duplication; and determining, by the mobile terminal, whether a configured grant (CG) resource allocated nearby the mobile terminal is available for use within the QoS requirement, and if yes, utilizing the CG resource to perform a PDCP retransmission or transmission; otherwise, sending an uplink (UL) grant message to the network to ask for a dynamic grant (DG) resource to perform a PDCP retransmission or transmission.
In accordance with one or more embodiments of the disclosure, performing the protocol layer QoS handling mechanism further includes: sending, by the network, a media access control (MAC) control element (CE) to the mobile terminal for activating the RLC entity in response to the first network condition.
In accordance with one or more embodiments of the disclosure, the method further includes: stopping, by the mobile terminal, the PDCP duplication in response to a second network condition.
In accordance with one or more embodiments of the disclosure, the method further includes: sending, by the network, a MAC CE to the mobile terminal for stopping the PDCP duplication in response to the second network condition.
In accordance with one or more embodiments of the disclosure, the network sends a radio resource control (RRC) message to the mobile terminal for deactivating the PDCP duplication in response to a third network condition.
In accordance with one or more embodiments of the disclosure, performing the physical layer QoS handling mechanism includes applying physical layer repetition to retransmit or transmit a data packet.
In accordance with one or more embodiments of the disclosure, the physical layer repetition includes at least one of CG physical uplink shared channel (PUSCH) repetition, DG PUSCH repetition or resource block (RB) repetition.
In accordance with one or more embodiments of the disclosure, performing the physical layer QoS handling mechanism includes modifying a modulation and coding scheme (MCS) indication to retransmit or transmit a data packet.
In accordance with one or more embodiments of the disclosure, performing the physical layer QoS handling mechanism includes performing Bandwidth Part (BWP) switching and/or beam sweeping on the mobile terminal and/or the network to retransmit or transmit a data packet.
In accordance with one or more embodiments of the disclosure, performing the physical layer QoS handling mechanism includes utilizing frequency hopping, multi-input multi-output (MIMO), non-orthogonal multiple access (NOMA), or uplink preemption to retransmit or transmit a data packet for high priority transmission.
In accordance with one or more embodiments of the disclosure, the MAC CE is extended based on CG/SPS configurations MAC CE or PDCP duplication MAC CE for indicating to support the QoS requirement.
In accordance with one or more embodiments of the disclosure, the method further includes: utilizing a MAC Protocol Data Unit (PDU) with an extended logical channel ID (eLCID) value for a Downlink Shared Channel (DL-SCH) or an uplink shared channel (UL-SCH) for supporting activation and deactivation of the service reliability procedure.
In accordance with one or more embodiments of the disclosure, the method further includes: setting a timer to handle packet transmissions and/or re-transmission during the service reliability procedure.
In accordance with one or more embodiments of the disclosure, the method further includes: setting a priority indicator to configure transmission priorities during the service reliability procedure.
In accordance with one or more embodiments of the disclosure, the method further includes: setting a periodicity value to handle packet transmissions during the service reliability procedure.
In accordance with one or more embodiments of the disclosure, the method further includes: configuring user equipment (UE) capability information to support the QoS requirement during the service reliability procedure.
In accordance with one or more embodiments of the disclosure, the method further includes: adjusting a transmission time interval (TTI), a periodicity or a priority, or enabling physical layer repetition and/or MCS for packet transmissions during the service reliability procedure.
In accordance with one or more embodiments of the disclosure, triggering the service reliability procedure includes: sending, from the mobile terminal, an RRC message to the network for indicating that the mobile terminal supports the QoS requirement; and adding or modifying, at the network, a resource allocation configuration to support the QoS requirement.
In accordance with one or more embodiments of the disclosure, the RRC message is an RRC setup message with UE capability information, an RRC resume message with UE capability information, an RRC reconfiguration message with UE capability information, an RRC UE capability information message or an RRC UL information transfer message.
The foregoing aspects and many of the accompanying advantages of this disclosure will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings.
The detailed explanation of the disclosure is described as following. The described preferred embodiments are presented for purposes of illustrations and description, and they are not intended to limit the scope of the disclosure.
Terms used herein are only used to describe the specific embodiments, which are not used to limit the claims appended herewith. Unless limited otherwise, the term “a,” “an,” “one” or “the” of the single form may also represent the plural form.
It will be understood that, although the terms “first,” “second,” “third” . . . etc., may be used herein to describe various elements and/or components, these elements and/or components, should not be limited by these terms. These terms are only used to distinguish elements and/or components.
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If the protocol layer procedure meets the QoS requirement, Step S306 is performed, in which the protocol layer QoS handling mechanism is adopted; otherwise, Step S308 is performed, in which the physical layer QoS handling mechanism is adopted. Following Step S306, in Step S310, the QoS requirement is used to determine whether to perform a network control based packet data convergence protocol (PDCP) duplication procedure or a user equipment (UE) control based PDCP duplication procedure. If the network control based PDCP duplication meets the QoS requirement, then Step S312 is performed, in which the network activates a network control based PDCP duplication procedure by sending a MAC control element (CE) to the mobile terminal for activating an RLC entity. The MAC CE may be used for indicating to support the QoS requirement. Otherwise, Step S314 is performed, in which the mobile terminal starts a UE control based PDCP duplication procedure by activating an RLC entity.
For the physical layer QoS handling mechanism, the transmission reliability may be improved by enhancing physical layer configurations at the mobile terminal and/or the network. In some embodiments, the physical layer QoS handling mechanism may be performed by applying physical layer repetition to retransmit or transmit a data packet. The physical layer repetition may include CG physical uplink shared channel (PUSCH) repetition, DG PUSCH repetition, resource block (RB) repetition, and/or another suitable repetition.
In some embodiments, the physical layer QoS handling mechanism may be performed by modifying a modulation and coding scheme (MCS) indication to retransmit or transmit a data packet, e.g., by downgrading the MCS to reduce the BER and/or the BLER.
In some embodiments, the physical layer QoS handling mechanism may be performed by performing Bandwidth Part (BWP) switching (e.g. allowing to switch to different BWPs) and/or beam sweeping on the mobile terminal and/or the network to retransmit or transmit data packets.
In some embodiments, the physical layer QoS handling mechanism may be performed by utilizing frequency hopping, multi-input multi-output (MIMO), non-orthogonal multiple access (NOMA), or uplink preemption to retransmit or transmit data packets with high priority according to the type of the wireless communication system and the capabilities of the mobile terminal and/or the network.
The wireless communication system may introduce a new QoS parameter for a new MAC CE or an existing MAC CE. The new MAC CE may be extended based on CG/SPS configurations MAC CE or PDCP duplication MAC CE. In addition, the wireless communication system may introduce a MAC Protocol Data Unit (PDU) with a new extended logical channel ID (eLCID) value for a Downlink Shared Channel (DL-SCH) and/or an uplink shared channel (UL-SCH) for supporting activation and deactivation of the service reliability procedure.
The wireless communication system may introduce a hybrid automatic repeat request (HARQ) process ID to enhance the HARQ feedback procedure to meet the QoS requirement. The enhanced HARQ feedback procedure may be performed in the physical layer to support (e.g. start and/or stop or measure) HARQ processes, or may be performed an upper layer (e.g. MAC layer, RLC layer or PDCP layer) to support (e.g. start and/or stop or measure) acknowledgement/negative-acknowledgement (ACK/NACK) processes. The base station may perform RRC configurations for the mobile terminal by exchange RRC messages with the mobile terminal for activating the service reliability procedure. Moreover, the core network in the network may perform core network configurations for the mobile terminal by exchange non-access stratum (NAS) messages with the mobile terminal for activating the service reliability procedure. In the network, the base station may exchange messages with the core network for activating the service reliability procedure.
The wireless communication system may introduce a new timer (e.g., a RRC timer) associated with the QoS requirement for a duration of transmission and/or retransmission. The new timer may be set to handle packet transmissions during the service reliability procedure.
The wireless communication system may introduce a new priority indicator to handle prioritization between the specific data packets and the other packets in the MAC layer and/or the physical layer. The new priority indicator may be set at the mobile terminal or the network to configure transmission priorities during the service reliability procedure.
The wireless communication system may introduce a new periodicity value or plural new periodicity values associated with the QoS requirement for transmission and/or retransmission periodicity. The new periodicity value(s) may be set at the mobile terminal or the network to handle packet transmissions and/or retransmissions during the service reliability procedure.
The wireless communication system may introduce new UE capability information for notifying support of the QoS requirement. The new UE capability information may be configured at the mobile terminal to support the QoS requirement during the service reliability procedure.
The wireless communication system may introduce a new transmission time interval (TTI), a new periodicity or a new priority or a new indicator for enabling physical layer repetition and/or MCS for the QoS requirement. The new TTI may be shorter than the original TTIs, the periodicity may be shorter than the original periodicities, the new priority may be higher than the original priorities, and the new indicator may be used to enable physical layer repetition and/or MCS for specific data packets. The new TTI, the new periodicity, the new priority and/or the new indicator may be applied for packet transmissions during the service reliability procedure.
The PDCP duplication may be stopped in response to a second network condition. The second network condition may be any condition in which the PDCP duplication can be stopped, e.g., a retransmission packet or a number of consecutive correct retransmission packets is/are correctly received, a retransmission packet or a number of consecutive retransmission packets is/are all received according to the HARQ feedback conditions, or the next new transmission packet or a number of consecutive transmission packets is/are received. The PDCP duplication may be stopped by the mobile terminal or the network. If a UE control based PDCP duplication stopping procedure is adopted, the mobile terminal may disable the activated RLC entity(ies) or disable packet duplication corresponding to the activated RLC entity(ies). The UE control based PDCP duplication stopping procedure may be performed without notifying the network. If a network control based PDCP duplication stopping procedure is adopted, the network sends a MAC CE to the mobile terminal for indicating which RLC entity(ies) is/are to be disabled, and then the mobile terminal disables the RLC entity(ies) or disable packet duplication corresponding to the RLC entity(ies) accordingly.
The PDCP duplication may be deactivated by the network in response to a third network condition. The third network condition may be any condition in which the PDCP duplication can be deactivated, e.g., the QoS service is no longer required, the QoS service is not supported, or the PDCP duplication function is unavailable. The network may send an RRC message to the mobile terminal for deactivating the PDCP duplication.
In the wireless communication system according to the embodiments of the disclosure, a handling mechanism similar to intra-UE prioritization is applied to meet the QoS requirement for new packets with a higher priority or the highest priority. When detecting transmission error(s), the mobile terminal or the network enables the functionality of QoS requirement support. The mobile terminal may duplicate the PDUs of the lost packets and performs an autonomous retransmission or a new transmission with the higher or highest propriety for the packets. The mobile terminal may select available allocated CG resource(s) to send the packets. Alternatively, the mobile terminal may issue an prioritized UL grant message and selects DG resource(s) to send packets, or else may utilize the DG resource(s) indicated by the network to send packets. The duplication may be performed for different RLC entities, for specific packets and/or both.
Similarly, the mobile terminal may duplicate the PDUs of the lost packets and performs an autonomous retransmission or a new transmission with the higher or highest priority for the packets. The network may select available allocated SPS resource(s) or allocate new SPS resource(s) to send packets. The duplication may be performed for different RLC entities, for specific packets and/or both.
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It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosure without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims.
This application claims priority to U.S. Provisional Application Ser. No. 63/136,651, filed Jan. 13, 2021, which is herein incorporated by reference.
Number | Date | Country | |
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63136651 | Jan 2021 | US |