WO2021239232A1 - Accusé de réception de paquet dans un réseau sans fil - Google Patents

Accusé de réception de paquet dans un réseau sans fil Download PDF

Info

Publication number
WO2021239232A1
WO2021239232A1 PCT/EP2020/064858 EP2020064858W WO2021239232A1 WO 2021239232 A1 WO2021239232 A1 WO 2021239232A1 EP 2020064858 W EP2020064858 W EP 2020064858W WO 2021239232 A1 WO2021239232 A1 WO 2021239232A1
Authority
WO
WIPO (PCT)
Prior art keywords
message
network node
channel
receiving
decoding
Prior art date
Application number
PCT/EP2020/064858
Other languages
English (en)
Inventor
Olli Alanen
Mika Kasslin
Lorenzo GALATI GIORDANO
Adrian GARCIA RODRIGUEZ
Original Assignee
Nokia Technologies Oy
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nokia Technologies Oy filed Critical Nokia Technologies Oy
Priority to PCT/EP2020/064858 priority Critical patent/WO2021239232A1/fr
Publication of WO2021239232A1 publication Critical patent/WO2021239232A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/1607—Details of the supervisory signal
    • H04L1/1671—Details of the supervisory signal the supervisory signal being transmitted together with control information
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
    • H04L1/1825—Adaptation of specific ARQ protocol parameters according to transmission conditions
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
    • H04L1/1829—Arrangements specially adapted for the receiver end
    • H04L1/1864—ARQ related signaling
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0002—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the transmission rate
    • H04L1/0003—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the transmission rate by switching between different modulation schemes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0009—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the channel coding
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
    • H04L1/1867—Arrangements specially adapted for the transmitter end
    • H04L1/1887—Scheduling and prioritising arrangements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
    • H04L1/1867—Arrangements specially adapted for the transmitter end
    • H04L1/1893—Physical mapping arrangements

Definitions

  • Various embodiments described herein relate to the field of wireless communications and, particularly, to acknowledging packets transmitted over a radio channel.
  • a multi-link capable device may be capable of communicating with another wireless device over a radio connection comprising multiple radio links. Operating multiple links concurrently may improve throughput and /or reduce channel access delays.
  • Packet acknowledgments in the context of wireless networks generally refers to a receiver acknowledging successful/failed decoding of a packet to a transmitter of the packet.
  • the receiver may send a positive acknowledgment and the transmitter becomes aware that no retransmission is needed.
  • the transmitter may send a retransmission of the packet to the receiver.
  • an apparatus comprising means for performing: receiving a first part of a first message on a first channel from a second network node of the wireless network; determining, while receiving the first message, that the apparatus is incapable of successfully completing decoding of the first message; in response to said determining and while receiving the first message, transmitting on a second channel a negative acknowledgment message to the second network node, wherein the negative acknowledgment comprises at least one information element indicating a reason why the apparatus is incapable of successfully completing the decoding of the first message; and receiving a retransmission of the first message.
  • the means are configured to transmit the negative acknowledgment message while receiving the first message and to cancel the reception of the first message.
  • the means are configured to perform said determining in response to processing the first part of the first message.
  • the means are configured to estimate a received signal quality indicator from the first part of the first message, to determine a modulation and coding scheme of the first message, and to determine that the apparatus is incapable of successfully completing the decoding of the first message because of too unreliable modulation and coding scheme, and wherein the retransmission of the first message is encoded with a more reliable modulation and coding scheme.
  • the means are configured to receive the first part of the first message and the retransmission of the first message during the same transmission opportunity of the second network node.
  • the means are configured to measure a received signal quality indicator for the first message, to determine that the apparatus is incapable of successfully completing the decoding of the first message because of too high interference indicated by the received signal quality indicator, and to cancel the reception of the first message.
  • the means are configured to receive, from the second network node in response to indicating said high interference as said reason, an end message ending a transmission opportunity associated with the first part of first message.
  • the means are configured to receive the first part of the first message in a first transmission opportunity of the second network node, to receive the end message during the first transmission opportunity, and to receive the retransmission of the first message in a second transmission opportunity of the second network node.
  • the means are configured to determine, while receiving the first part of the first message, that the apparatus is incapable of successfully completing the decoding of the first message because of a need to transmit uplink data, to cancel the reception of the first message, and to transmit a message comprising the uplink data.
  • the first message comprises a physical layer protocol data unit.
  • an apparatus for a first network node of a wireless network comprising means for performing: transmitting a first part of a first message on a first channel to a second network node of the wireless network; receiving, from the second network node on a second channel while transmitting the first message, a negative acknowledgment message for the first message, the negative acknowledgment message comprising at least one information element indicating a reason why the second network node is incapable of successfully completing decoding of the first message; and changing, in response to the at least one information element, at least one transmission parameter of the first message and performing a retransmission of the first message with the changed at least one transmission parameter.
  • the means are configured to cancel the transmission of the first message in response to receiving the negative acknowledgment.
  • the at least one information element indicates a need of the second network node to transmit uplink data
  • the means are configured to, in response to the at least one information element, cancel the transmission of the first message, and to receive from the second network node on the first channel or on the second channel a message comprising the uplink data.
  • the at least one information element indicates an unreliable modulation and coding scheme
  • the changed at least one parameter comprises a more reliable modulation and coding scheme
  • the means are configured to transmit the first part of the first message and the retransmission of the first message during the same transmission opportunity.
  • the first part of the first message is comprised in a first transmission opportunity of the apparatus, wherein the at least one information element indicates high interference, and wherein the changed at least one parameter comprises a different transmission time that is comprise in a second transmission opportunity of the apparatus.
  • the means are configured to, in response to the at least one information element, cancel the transmission of the first message and to schedule the second network node or another network node to transmit a message during the first transmission opportunity.
  • the first part of the first message comprises a header of the first message.
  • the means comprises at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.
  • a method for a first network node of a wireless network comprising: receiving, by the first network node, a first part of a first message on a first channel from a second network node of the wireless network; determining, by the first network node while receiving the first message, that the first network node is incapable of successfully completing decoding of the first message; in response to said determining and while receiving the first message, transmitting by the first network node on a second channel a negative acknowledgment message to the second network node, wherein the negative acknowledgment comprises at least one information element indicating a reason why the first network node is incapable of successfully completing the decoding of the first message; and receiving, by the first network node, a retransmission of the first message.
  • the first network node transmits the negative acknowledgment message while receiving the first message and cancels the reception of the first message.
  • the first network node performs said determining in response to processing the first part of the first message.
  • the first network node estimates a received signal quality indicator from the first part of the first message, determines a modulation and coding scheme of the first message, and determines that the first network node is incapable of successfully completing the decoding of the first message because of too unreliable modulation and coding scheme, and wherein the retransmission of the first message is encoded with a more reliable modulation and coding scheme.
  • the first network node receives the first part of the first message and the retransmission of the first message during the same transmission opportunity of the second network node.
  • the first network node measures a received signal quality indicator for the first message, determines that the first network node is incapable of successfully completing the decoding of the first message because of too high interference indicated by the received signal quality indicator, and cancels the reception of the first message.
  • the first network node receives, from the second network node in response to indicating said high interference as said reason, an end message ending a transmission opportunity associated with the first part of first message.
  • the first network node receives the first part of the first message in a first transmission opportunity of the second network node, receives the end message during the first transmission opportunity, and receives the retransmission of the first message in a second transmission opportunity of the second network node.
  • the first network node determines, while receiving the first part of the first message, that the first network node is incapable of successfully completing the decoding of the first message because of a need to transmit uplink data, cancels the reception of the first message, and transmits a message comprising the uplink data.
  • the first message comprises a physical layer protocol data unit.
  • a method for a first network node of a wireless network comprising: transmitting, by the first network node, a first part of a first message on a first channel to a second network node of the wireless network; receiving, by the first network node from the second network node on a second channel while transmitting the first message, a negative acknowledgment message for the first message, the negative acknowledgment message comprising at least one information element indicating a reason why the second network node is incapable of successfully completing decoding of the first message; and changing, by the first network node in response to the at least one information element, at least one transmission parameter of the first message and performing a retransmission of the first message with the changed at least one transmission parameter.
  • the first network node cancels the transmission of the first message in response to receiving the negative acknowledgment.
  • the at least one information element indicates a need of the second network node to transmit uplink data
  • the first network node cancels, in response to the at least one information element, the transmission of the first message, and receives from the second network node on the first channel or on the second channel a message comprising the uplink data.
  • the at least one information element indicates an unreliable modulation and coding scheme, and wherein the changed at least one parameter comprises a more reliable modulation and coding scheme.
  • the first network node transmits the first part of the first message and the retransmission of the first message during the same transmission opportunity.
  • the first part of the first message is comprised in a first transmission opportunity of the first network node, wherein the at least one information element indicates high interference, and wherein the changed at least one parameter comprises a different transmission time that is comprise in a second transmission opportunity of the first network node.
  • the first network node cancels, in response to the at least one information element, the transmission of the first message and schedules the second network node or another network node to transmit a message during the first transmission opportunity.
  • the first part of the first message comprises a header of the first message.
  • a computer program product embodied on a computer-readable medium and comprising a computer program code readable by a computer for a first network node of a wireless network, wherein the computer program code configures the computer to carry out a computer process comprising: receiving a first part of a first message on a first channel from a second network node of the wireless network; determining, while receiving the first message, that the first network node is incapable of successfully completing decoding of the first message; in response to said determining and while receiving the first message, transmitting on a second channel a negative acknowledgment message to the second network node, wherein the negative acknowledgment comprises at least one information element indicating a reason why the first network node is incapable of successfully completing the decoding of the first message; and receiving a retransmission of the first message.
  • a computer program product embodied on a computer-readable medium and comprising a computer program code readable by a computer for a first network node of a wireless network, wherein the computer program code configures the computer to carry out a computer process comprising: transmitting a first part of a first message on a first channel to a second network node of the wireless network; receiving, from the second network node on a second channel while transmitting the first message, a negative acknowledgment message for the first message, the negative acknowledgment message comprising at least one information element indicating a reason why the second network node is incapable of successfully completing decoding of the first message; and changing, in response to the at least one information element, at least one transmission parameter of the first message and performing a retransmission of the first message with the changed at least one transmission parameter.
  • any one of the above-described computer program products further comprises a computer program code that configures the computer to carry out the steps of any one of the above-described embodiments of any one of the above-described methods.
  • Figure 1 illustrates a wireless communication scenario to which some embodiments of the invention may be applied
  • FIGS 2 and 3 illustrate embodiments of processes for communicating and acknowledging messages
  • Figure 4 illustrates a signalling diagram illustrating an embodiment of a procedure combining the embodiments of Figures 2 and 3;
  • Figures 5 to 8 illustrate various embodiments for cancelling an on-going transmission with a negative acknowledgment message and for subsequent operation during the remaining transmission opportunity
  • FIGS 9 and 10 illustrate block diagrams of structures of apparatuses according to some embodiments.
  • FIG. 1 illustrates wireless communication devices comprising a plurality of access points (AP) 110, 112 and a plurality of wireless terminal devices or stations (STA) 100, 102, 104.
  • Each AP may be associated with a basic service set (BSS) which is a basic building block of an IEEE 802.11 wireless local area network (WLAN).
  • BSS basic service set
  • the most common BSS type is an infrastructure BSS that includes a single AP together with all STAs associated with the AP.
  • the AP may be a fixed AP or it may be a mobile AP, and a general term for an apparatus managing a wireless network such as the BSS and providing the stations with wireless services is an access node.
  • the APs 110, 112 may also provide access to other networks, e.g. the Internet.
  • the BSS may comprise a plurality of APs to form an extended service set (ESS), e.g. the AP 110 or 112 may belong to the same ESS with another AP and have the same service set identifier (SSID).
  • ESS extended service set
  • the APs 110, 112 are considered to provide different wireless networks (different BSSs), overlapping BSSs (OBSS) operating at least partially on the same channels. While embodiments of the invention are described in the context of the above-described topologies of IEEE 802.11 based networks, it should be appreciated that these or other embodiments of the invention may be applicable to networks based on other specifications, e.g.
  • WiMAX Worldwide Interoperability for Microwave Access
  • UMTS LTE Long-term Evolution for Universal Mobile Telecommunication System
  • cognitive radio features e.g. transmission medium sensing features and adaptiveness to coexist with radio access networks based on different specifications and/or standards.
  • IEEE 802.11h specification specifies a data transmission mode that includes 20 megahertz (MHz) wide primary and secondary channels.
  • the primary channel is used in all data transmissions with clients supporting only the 20 MHz mode and with clients supporting higher bandwidths.
  • a further definition in 802.11h is that the primary and secondary channels are adjacent.
  • the 802.11h specification also defines a mode in which a STA may, in addition to the primary channel, occupy one secondary channel which results in a maximum bandwidth of 40 MHz.
  • IEEE 802.11ac amendment extends such an operation model to provide for wider bandwidths by increasing the number of secondary channels from 1 up to 7, thus resulting in bandwidths of 20 MHz, 40 MHz, 80 MHz, and 160 MHz.
  • a 40 MHz transmission band may be formed by two contiguous 20 MHz bands, and an 80 MHz transmission band may be formed by two contiguous 40 MHz bands. However, a 160 MHz band may be formed by two contiguous or non-contiguous 80 MHz bands.
  • 802.11ax Some IEEE 802.11 networks employ channel contention based on carrier sense multiple access with collision avoidance (CSMA/CA) for channel access.
  • CSMA/CA carrier sense multiple access with collision avoidance
  • the CSMA/CA is an example of a physical carrier sensing function to determine whether the first channel and the second channel, respectively, is busy or idle.
  • Every device attempting to gain a transmission opportunity (TXOP) is reducing a backoff value while the primary channel is sensed to be idle for a certain time interval.
  • the backoff value may be selected randomly within a range defined by a contention window parameter.
  • the contention window may have different ranges for different types of traffic, thus affecting priority of the different types of traffic.
  • the channel sensing may be based on sensing a level of radio energy in the radio channel.
  • the sensed level may be compared with a threshold: if the sensed level is below the threshold level, the channel may be determined to be idle (otherwise busy).
  • CCA clear channel assessment
  • the backoff value computation maybe suspended, and the device continues the backoff computation after the TXOP of the other device has ended and the primary channel is sensed to be idle.
  • the time duration (the backoff value) may not be decremented during the TXOP of the other device, but the time duration that already lapsed before the suspension may be maintained, which means that the device now has a higher probability of gaining the TXOP.
  • the device wins the channel contention and gains access to the channel it may transmit a frame that defines a reservation period for the channel access.
  • the reservation period may be defined by a duration field in the frame.
  • any other device contending on the same channel may set a network allocation vector (NAV) for the duration of the reservation period and refrain the contention on the channel for the duration of the reservation period.
  • NAV network allocation vector
  • the use of NAV for determining that the channel is busy is called virtual carrier sensing in some literature.
  • a device may employ different access parameters for the different frames.
  • the differing access parameters may comprise quality-of-service (QoS) parameters such as enhanced distributed channel access (EDCA) parameters of IEEE 802.11 technology.
  • QoS quality-of-service
  • EDCA enhanced distributed channel access
  • the EDCA parameters may comprise a plurality of access categories (AC) for prioritizing frame transmissions.
  • the access categories may comprise the following priority levels in the order of increasing priority: background (AC_BK), best effort (AC_BE), video streaming (AC_VI), and voice (AC_VO).
  • a higher priority frame transmission may use a shorter contention window and a shorter arbitration inter-frame spacing (AIFS) that result in higher probability of gaining the TXOP.
  • AIFS arbitration inter-frame spacing
  • the STA 100, 102, 104 may be considered to be a terminal device or a station capable of connecting or associating to any one of the APs 110, 112.
  • the STA may establish a connection with any one of APs it has detected to provide a wireless connection within the neighbourhood of the STA.
  • the connection establishment may include authentication in which an identity of the STA is established in the AP.
  • the authentication may comprise setting up an encryption key used in the BSS.
  • the AP and the STA may carry out association in which the STA is fully registered in the BSS, e.g. by providing the STA with an association identifier (AID).
  • AID association identifier
  • a separate user authentication may follow association, which may also comprise building an encryption key used in the BSS.
  • association of the STA to an AP should be understood broadly as establishing a connection between the STA and the AP such that the STA is in a connected state with respect to the AP and waiting for downlink frame transmissions from the AP and monitoring its own buffers for uplink frame transmissions.
  • a STA not associated to the AP is in an unassociated state.
  • An unassociated STA may still exchange some frames with the AP, e.g. discovery frames.
  • a multi-link feature has been introduced. For example, there has been discussions in IEEE 802.11be task group related to developing a capability of accessing multiple channels concurrently and independently of one another.
  • IEEE 802.11be task group related to developing a capability of accessing multiple channels concurrently and independently of one another.
  • a protocol layer of STA 102 that represents a legacy device with no such multi-link capability.
  • a single protocol stack is supported where there is a single protocol entity on a physical layer 144 and on upper and lower medium access control (MAC) layers 140, 142.
  • the physical layer 144 may handle radio frequency and baseband signal processing tasks in the transmission and reception.
  • the lower MAC layer 142 may be responsible for channel contention, including the NAV, CCA etc.
  • the upper MAC layer 140 may be responsible of the association and authentication procedures, for example.
  • multiple MAC layers and multiple physical layers may be provided but the number of MAC layers is equal to the number of physical layers.
  • the legacy devices may support operation multiple channels with the condition that the channel contention is performed only on the primary channel.
  • the device may transmit a frame on the primary channel and, further, on one or more secondary channels.
  • the CCA procedure may be executed on the secondary channel(s) to ensure that they are also free for transmission.
  • the split of the MAC layer into lower and upper MAC layer may be logical and/or physical. For example, a different physical entity may execute functions of the lower MAC layer than a physical entity executing functions of the upper MAC layer.
  • the device includes only a single MAC layer handling the functions described above for the lower MAC layer and functions described above for the upper MAC layer.
  • legacy device may follow the definition conventionally used in the field.
  • a legacy device may refer to an outdated or earlier version of a communication protocol that is still operational in the wireless networks, together with modern devices supporting later or latest version(s) of the communication protocol.
  • the embodiments described below relate to a wireless device with multi- link-capability and having multiple parallel lower protocol layers, e.g. the STA 100 or the access node 110.
  • the STA 100 may support a single upper MAC layer 130 and multiple lower MAC layers 132, 134, and a physical layer 136, 138 per lower MAC layer 132, 134.
  • the access node 110 may have a corresponding protocol stack where there are multiple parallel (lower) MAC layers 122, 124 below a single upper MAC layer 120, and a physical layer 126, 128 per (lower) MAC layer.
  • the access node 110 and/or the terminal device 100 supports a single upper MAC layer 120, 130 and multiple lower MAC layers 122, 124, 132, 134, as depicted in Figure 1, but a single physical layer that serves multiple lower MAC layers.
  • the multiple lower protocol layers (per upper MAC layer) enable the wireless device to contend, within the same association, simultaneously on multiple channels and to transmit in parallel and independently on the multiple channels.
  • the single association may be called a multi-link association enabled by the multiple physical layers (and multiple lower MAC layers) per upper MAC layer. This distinguishes from those legacy devices that have multiple physical layers and multiple lower MAC layers but only single physical layer and a single lower MAC layer per upper MAC layer.
  • the multi-link capability also enables a plurality of associations between lower MAC layers within a single association between upper MAC layers of wireless devices.
  • the channels of the multi-link association may be on different frequency bands close to or distant from one another.
  • the distant may be understood as so separated that it may not feasible to transmit or receive on the channels at the same time without using a dedicated radio front end (physical layer) for each channel.
  • the STA 100 or access node 110 supporting multiple physical layers may be capable of transmitting or receiving a frame concurrently on channels of multiple distant frequency bands.
  • one of the channels may include a channel on a 2.4 GHz band while another one of the channels may include a channel on a 5 GHz band.
  • Other systems may employ other frequency bands.
  • the channels may be provided on the same frequency band as well.
  • a wireless device having a single physical layer serving multiple lower MAC layers may be capable of transmitting or receiving frames concurrently on multiple channels of a single frequency band, e.g. the 2.4 GHz band or 5 GHz band.
  • a single frequency band e.g. the 2.4 GHz band or 5 GHz band.
  • These embodiments alleviate the channel access in the sense that the wireless device 100, 110 is not necessarily limited by the congestion on one of the channels or bands of the wireless network, e.g. the primary channel.
  • device implementations may cause some restrictions on capabilities of transmitting simultaneously over multiple links.
  • the devices may have capability of indicating such restrictions to other devices, e.g. via one or more information elements in data frames and/or management frames.
  • the terminal device 100 may be described to comprise multiple STA entities, wherein a first STA entity operates the lower MAC layer 132 and the physical layer 136 on a first channel of a multi-link association, and a second (different) STA entity operates the lower MAC layer 134 and the physical layer 138 on a second channel of the multi-link association. Both STA entities may serve the same upper MAC layer and/or the same another upper layer in the protocol stack.
  • the terminal device may have a single physical layer that serves multiple lower MAC layers, e.g. the lower MAC layer 132 and the lower MAC layer 134.
  • the stations 100, 102 are associated to the access node 110 while the station 104 is associated to the access node 112.
  • the stations 100, 102 (and 104) and the APs 110, 112 may be within the proximity of one another such that every device is capable of detecting one another’s transmissions, when transmitted on the same channel.
  • the legacy station 102 may be capable of detecting the transmissions of the APs 110, 112 and the STA 100.
  • the STA 100 may also be capable of detecting the transmissions of at least the APs 110, 112 and the STA 102.
  • a common but undesired event is that sometimes wireless transmissions fail.
  • a transmission may fail because of, for example, poor radio channel conditions or a collision of two transmissions accessing the same transmission medium, e.g. concurrently the same channel.
  • Such transmissions waste capacity of the transmission medium and the communicating devices.
  • Figure 2 illustrates a process for one network node, e.g. the terminal device 100 or 104 while Figure 3 illustrates a process for another network node, e.g. the access node 110 or 112.
  • the process for a first network node comprises: receiving (block 200) a first part of a first message on a first channel from a second network node of the wireless network; determining, while receiving the first message, that the first network node is incapable of successfully completing decoding of the first message; in response to said determining and while receiving the first message, transmitting (block 204) on a second channel a negative acknowledgment message to the second network node, wherein the negative acknowledgment comprises at least one information element indicating a reason why the first network node is incapable of successfully completing the decoding of the first message; and receiving (block 206) a retransmission of the first message.
  • the first network node may be the terminal device 100 and the second network node may be the access node 110.
  • the second network node may be another terminal device.
  • the first network node determines in block 202 whether or not it is capable of completing the decoding of the received first message. As described in the embodiments below, there may be various reasons for making the determination. The determination may be made while the first network node is still receiving the first message, and while the second network node is still transmitting the first message. The determination may be made while decoding the first message or even before the decoding is started in the first network node. Upon determining that the first network node is incapable of completing the decoding, the process may proceed to block 204, as described above. Otherwise, the process may proceed to block 208 where the decoding is completed or where the decoding is performed. In some embodiments, the first network node transmits a positive acknowledgment message to the second network node upon successfully decoding the first message.
  • the procedure comprises: transmitting (block 300) the first part of the first message on the first channel to the first network node of the wireless network; receiving (block 304), from the first network node on a second channel while transmitting the first message, the negative acknowledgment message for the first message, the negative acknowledgment message comprising the at least one information element indicating the reason why the first network node is incapable of successfully completing decoding of the first message; and changing (block 306), in response to the at least one information element, at least one transmission parameter of the first message and performing (block 308) a retransmission of the first message with the changed at least one transmission parameter.
  • the transmission of the first message in block 300 may result in one of at least three outcomes, wherein one is the execution of blocks 204 to 206 and 304 to 308. As described above, blocks 204 and 304 may be performed while transmitting/receiving the first message. Another outcome is that the first network node determines to be capable of completing the decoding and is capable of successfully decoding the first message in which case the first network node may transmit the positive acknowledgment in block 210 and the second network node may receive the acknowledgment in block 312. As a result, the second network node may determine the first message as successfully delivered to the first network node.
  • the second network node completes the transmission of the first message
  • the first network node determines in block 202 to be capable of successfully completing the decoding, attempts decoding but fails in the decoding.
  • the first network node may indicate the failed decoding to the second network node.
  • the indication may be transmission of a negative acknowledgment message or transmission of no acknowledgment message.
  • the second network node may in block 310 determine that the reception of the first message has failed and perform the retransmission (block 308).
  • the second network node may also perform block 306 at this stage and change at least one transmission parameter for the retransmission of the first message so as to improve the probability of successfully delivering the first message to the second network node in the retransmission.
  • blocks 204 and 304 are performed before the transmission and reception of the entire first message is completed.
  • the second part may comprise a tail of the first message, e.g. at least a part of payload data of the first message.
  • the end of the first message comprises cyclic redundancy check (CRC) bits or control information
  • CRC cyclic redundancy check
  • the first message comprises a first frame.
  • the first frame is a physical layer (PHY) frame, e.g. a physical layer (PHY) protocol data unit (PPDU).
  • PHY physical layer
  • PPDU protocol data unit
  • the first message comprises a protocol data unit such as a physical layer convergence protocol (PLCP) protocol data unit.
  • PLCP physical layer convergence protocol
  • the first message comprises one or a plurality of medium access control (MAC) protocol data units (MPDU).
  • MPDU medium access control
  • the first message comprises at least one header and at least one payload part.
  • the headers may comprise a PLCP header and a MAC header.
  • inventions of Figures 2 and 3 provide several advantages, at least increased spectral efficiency and reduced latency.
  • the increased spectral efficiency results from the capability of the second network node to cancel the transmission of the first message that shall not be successfully decoded.
  • the first channel would be freed for other transmissions.
  • the latency would be improved for the same reason: the first channel may be accessed earlier for another transmission.
  • the second network node upon receiving the negative acknowledgment message in block 304, cancels the transmission of the first message. Similarly, the first network node also cancels the reception of the first message. The reception may be cancelled upon determining to transmit the negative acknowledgment or in response to the second network node cancelling the transmission, for example.
  • Figure 4 illustrates such an embodiment that also combines the processes of Figures 2 and 3.
  • the first network node is the terminal device and the second network node is the access node 110, but the embodiment and also the other embodiments described below can be applied to other communication scenarios in a straightforward manner, e.g. to the peer communications or to the reversed scenario where the terminal device 100 transmits and the access node 110 receives the first message.
  • Figure 4 also illustrates the timing of the executions of the various blocks of Figures 2 and 3.
  • the access node 110 may perform the transmission (block 300) of the first message while the terminal device 100 is receiving (block 200) the first message on the first channel (channel 1). While the access node 110 is transmitting the first message, the terminal device may also perform blocks 202 and 204 and transmit the negative acknowledgment message to the access node 110 on the second channel (channel 2). As described above in connection with Figure 1, depending on the protocol stacks employed by the terminal device 100 and the access node, the channels 1 and 2 may be on the same frequency band (e.g. 2.4 GHz band or 5 GHz band), or on different frequency bands. In any case, the access node 110 may be configured to monitor the second channel for a frame transmission while transmitting the first message on the first channel.
  • the channels 1 and 2 may be on the same frequency band (e.g. 2.4 GHz band or 5 GHz band), or on different frequency bands.
  • the access node 110 may be configured to monitor the second channel for a frame transmission while transmitting the first message on the first channel.
  • the access node may cancel the transmission of the remaining part of the first message, as indicated by the explosion below block 300. Thereafter, the access node 306 may perform the part of block 306 where it changes the at least one parameter and the part where it performs the retransmission of the first message to the terminal device.
  • the retransmission may comprise at least partly the same information that was contained in the first transmission of the first message in block 300.
  • the information may be encoded in a different manner, e.g. with a different modulation and coding scheme or with a different number of error detection and decoding information, it may be transmitted in different radio resources, or another parameter may be changed in block 306.
  • the retransmission of the first message in block 306 may or may not be identical to the first transmission of the first message in block 300. However, logically it may still be understood as a retransmission of the same message.
  • the negative acknowledgment message may be specified in a form of a control frame or as an action frame. Regardless of the type, the frame may include a reason code field, that may be for example one bit or two bits or three bits or four bits, depending on the number of different reason codes.
  • the capability of sending the negative acknowledgment while transmitting/receiving the first message may be enabled and activated/deactivated by the access node.
  • the access node may enable the feature in the terminal device(s) by transmitting a message comprising at least one information element indicating such enablement/disablement.
  • the feature may be enabled only for some traffic transferred.
  • the enablement may be for a subset of access categories or traffic identifiers, or for frames or PPDUs exceeding a certain specified duration limit, i.e. the feature would be enabled only for frames or PPDUs long enough and disabled for short frames.
  • the first network node performs the determining of being incapable of completing the decoding in response to processing the first part of the first message.
  • Figures 5, 7, and 8 illustrate embodiments where the first network node first processes the first part of the first message and, on the basis of the processing determines the capability of successfully decoding the first message.
  • Figure 5 illustrates an embodiment where the terminal device 100 estimates a received signal quality indicator from the first part of the first message, determines a modulation and coding scheme of the first message, and determines that the apparatus is incapable of successfully completing the decoding of the first message because of too unreliable modulation and coding scheme for current channel conditions. The determination may be based on measuring the current channel conditions and determining the modulation and coding scheme of the first message. Such an embodiment is described in greater detail below.
  • the access node (the second network node) may then encode the retransmission of the first message with a more reliable modulation and coding scheme.
  • MCS modulation and coding scheme
  • a more reliable MCS adds more redundancy to the data and, thus, reduces effective data rate but improves the probability of successfully delivering the data over the radio channel.
  • Modulation schemes in an order of increasing reliability include: 256 quadrature amplitude modulation (QAM) providing high data rate with lower reliability, 64 QAM, 16QAM, quadrature phase shift keying (QPSK), binary PSK (BPSK) providing the lowest data rate with highest probability of successfully delivering the data over the radio channel.
  • QAM quadrature amplitude modulation
  • QPSK quadrature phase shift keying
  • BPSK binary PSK
  • Various channel coding schemes have been introduced with varying capabilities in terms of the data rate and the reliability, e.g. block codes, Reed-Solomon codes, low-density parity check codes, and turbo codes.
  • the terminal device may process at least the first part of the first message in block 500.
  • the processing may include decoding/receiving a preamble/header of the first message. If the decoding/receiving of the preamble/header fails, the terminal device may trigger step 204. If the decoding/receiving is successful, the terminal device may proceed to decode the remaining part(s) of the first message.
  • the terminal device measures a reference signal or a pilot signal comprised in the first part of the first message, e.g. in a preamble of the first message.
  • the measurement may include measuring a signal quality metric that may be a signal strength value or another value indicating signal quality.
  • the signal strength value are reference signal reception power (RSRP), signal-to-interference-plus-noise power ratio (SINR), and received signal strength indicator (RSSI).
  • the signal quality metric that represents an embodiment of the received signal quality indicator may then be evaluated with one or more threshold for determining whether or not the decoding shall succeed.
  • the terminal device may store a threshold for each MCS for making the determination.
  • the terminal device may perform the measurements and determine the MCS of the first message from an information element comprised in the first part.
  • the first part may include a specific information element indicating the MCS so as to enable the decoding.
  • the terminal device may acquire a corresponding threshold value from the database and compare the measured signal quality metric with the threshold. If the comparison indicates a higher signal quality than the threshold quality for successfully decoding the first message, the terminal device may proceed with the decoding and omit block 204. If the comparison indicates a signal quality lower than the threshold quality, the terminal device may proceed to transmit the negative acknowledgment in block 204.
  • Other embodiments for estimating the capability of successfully decoding the first message on the basis of processing the first part can be envisaged.
  • the above- described procedure for processing the first part in block 500 and then making the determination in block 202 may be used for also filling the reason in the negative acknowledgment.
  • the information element(s) indicating the reason may indicate 'unreliable MCS’ or 'change to more reliable MCS’, or another indication that the reason for the incapability of completing the decoding is too unreliable MCS.
  • the access node may read the reason from the negative acknowledgment and, as a response to the reason being 'unreliable MCS’ or 'change to more reliable MCS’, or another indication that the reason for the incapability of completing the decoding is too unreliable MCS, the access node may change to a more reliable MCS in block 502 for the retransmission. For example, the access node may change the modulation scheme and/or the channel coding scheme to a more reliable one (see above for the order of reliability). Then, the access node may perform the retransmission with the more reliable MCS in block 306. Upon successfully decoding the retransmitted first message (block 504), the terminal device may transmit and the access node receive the positive acknowledgment in blocks 210 and 312, respectively.
  • the first part of the first message and the retransmission of the first message may be transmitted by the access node during the same transmission opportunity of the access node, as indicated in Figure 5.
  • the cancellation of the first transmission may expedite the retransmission and enable the retransmission.
  • the transmitter the access node in this case
  • the transmitter may employ a more aggressive MCS selection policy than in a conventional situation where the acknowledgment is transmitted only after fully attempting the decoding and succeeding or failing in the decoding.
  • a conventional solution could be to tune a link adaptation algorithm to target to about 5% packet error rate, but with the embodiment of Figure 5 a higher packet error rate target might be targeted with the selection of the MCS.
  • the first network node determines, while receiving the first part of the first message, that it is incapable of successfully completing the decoding of the first message because of a need to transmit uplink data. As a consequence, the first network node transmits the negative acknowledgment, cancels the reception of the first message, and transmits a message comprising the uplink data on the first channel and/or on the second channel.
  • Figure 6 illustrates such an embodiment.
  • the terminal device may operate an application transferring high priority data, e.g. data that requires very low latencies.
  • An example of such data is ultra-reliable low latency (URLLC) data defined in the specifications of the 3 rd Generation Partnership Project (3GPP) for the fifth generation (5G) cellular communication systems.
  • URLLC ultra-reliable low latency
  • 5G fifth generation
  • the terminal device may detect in block 600 the urgent need to transmit the uplink data. The detection may be based on detecting the uplink data in an uplink buffer of the terminal device, for example.
  • the terminal device may execute block 204 and add to the information element indicating the reason a value that indicates the need to transmit high-priority uplink traffic. In another embodiment, the reason may be indicated in another manner that indicates to the access node the need to cancel the transmission of the first message and to free the channel(s) for the terminal device.
  • the terminal device may also terminate the reception of the first message and start to monitor the channel 1 and/or 2 for an uplink transmission opportunity.
  • the access node may perform block 306 (change transmission parameter(s)) by postponing the transmission timing of the first message (block 602). From another perspective, the access node changes the transmission resources of the first message.
  • the access node may transmit a trigger frame to the terminal device in step 604 on channel 1 and/or channel 2, depending on which channel the access node 110 chooses to trigger the uplink transmission.
  • the terminal device may transmit the uplink data in one or more uplink frames in step 606.
  • the access node may suspend any transmission and, upon the terminal device detecting the channel 1 and/or 2 to be idle, the terminal device may proceed with channel access and uplink transmission during the transmission opportunity.
  • the uplink transmission may be performed in the same TXOP where the first part of the first message was transmitted (blocks 200 and 300).
  • the terminal device may cancel the reception and start channel contention for uplink transmission on channel 1 and/or channel 2.
  • the access node may perform the retransmission in a subsequent TXOP, for example, as described above.
  • the terminal device may determine, on the basis of the received signal quality indicator that the apparatus is incapable of successfully completing the decoding of the first message because of too high interference and, as a consequence, cancels the reception of the first message.
  • the terminal device may measure the reference signal or the pilot signal comprised in the first part of the first message. The measurement may include measuring the signal quality metric that may be the signal strength value or another value indicating signal quality. The signal quality metric that represents an embodiment of the received signal quality indicator may then be evaluated with a threshold for determining whether or not the decoding shall succeed.
  • the terminal device may determine whether or not the signal quality is so low that the successful decoding with any MCS shall succeed.
  • the database may store such a threshold value that indicates a limit where the signal quality is so low that the retransmission is better to be postponed and the channel freed for other terminal devices.
  • Figures 7 and 8 illustrate such embodiments.
  • the terminal may measure the first part of the first message in block 700 and estimate the received signal quality indicator. Then, the terminal device may compare the signal quality indicator with the threshold indicating the limit for an interference where the decoding is deemed to be impossible to complete successfully. If the comparison indicates a higher signal quality than the threshold for successfully decoding the first message, the terminal device may proceed with the decoding and omit block 204. If the comparison indicates a signal quality lower than the threshold, the terminal device may proceed to transmit the negative acknowledgment in block 204.
  • the above- described procedure for processing the first part in block 700 and then making the determination in block 202 may be used for also filling the reason in the negative acknowledgment.
  • the information element(s) indicating the reason may indicate 'too high interference’, or another indication that the reason for the incapability of completing the decoding is such bad channel conditions that it is considered that the decoding the first message with any transmission parameters shall fail, at least for the moment.
  • the access node may again cancel the transmission of the first message.
  • the access node may read the reason from the negative acknowledgment and, as a response to the reason being 'too high interference’ or a corresponding indication, the access node may carry out block 600 and postpone the transmission of the first message and any other message to the terminal device.
  • the postponement may extend at least to another TXOP, as illustrated in Figure 7. And as illustrated in Figure 7, there are unused resources of the TXOP 1 where the first part of the first message was transmitted. These resources may be used by the access node 110 to transmit frames between other terminal devices, e.g. the terminal device 102 (block 700).
  • the access node may thus schedule the remaining resources of the TXOP
  • TXOP 2 A subsequent TXOP (TXOP 2) may then be used for performing the retransmission of the first message in the above-described manner.
  • the duration of the postponement i.e. the time difference between the TXOP 1 and TXOP 2 may depend on the configuration. For example, there may be one or more TXOPs of the access node 110, terminal device 100, and/or other devices between the TXOPs 1 and 2.
  • the TXOP 2 may directly follow TXOP 1, provided that the access node 110 is able to gain the TXOP
  • Figure 8 illustrates another embodiment related to the terminal device 100 reporting 'too high interference’ in the negative acknowledgment message.
  • the access node 110 may transmit and the terminal device receive, in response to indicating the high interference as the reason, an end message ending the TXOP associated with the first part of first message (blocks 200 and 300).
  • the access node may carry out block 600 and postpone the retransmission of the first message, as described above.
  • the access node may, upon cancelling the transmission of the first message, end the TXOP 1 by transmitting the end message in step 800.
  • the end message may be a contention-free-end (CF-End) message.
  • the end message may be transmitted on channel 1, i.e. on the same channel where the cancelled first message was transmitted.
  • the terminal device may prepare and transmit an acknowledgment frame on channel 1 to acknowledge reception of the end frame.
  • the terminal device may not be able to detect and decode the end frame.
  • the end frame may be an indicator to other devices that the TXOP has ended and that the channel contention by such other devices is possible. The retransmission can then be carried out in a subsequent frame, as described above in connection with Figure 7.
  • Figure 9 illustrates an embodiment of a structure of the above-mentioned functionalities of an apparatus executing the functions of the apparatus in the process of Figure 2 or any one of the embodiments of Figure 2 described above.
  • the apparatus may be a wireless device such as the STA 100.
  • the apparatus may be an access node, e.g. the AP 110.
  • the apparatus may comply with 802.11 specifications or specifications of another wireless network.
  • the apparatus may be or may be comprised in a computer (PC), a laptop, a tablet computer, a cellular phone, a palm computer, a sensor device, a router device, or any other apparatus provided with radio communication capability.
  • PC computer
  • the apparatus carrying out the process of Figure 2 or any one of its embodiments is comprised in such a wireless device, e.g. the apparatus may comprise a circuitry, e.g. a chip, a chipset, a processor, a micro controller, or a combination of such circuitries in the wireless device.
  • the apparatus may be an electronic device comprising electronic circuitries for realizing some embodiments of the wireless device.
  • the apparatus may comprise a communication circuitry 50 providing the apparatus with capability of communicating in at least one wireless network.
  • the communication circuitry may employ a radio interface providing the apparatus with radio communication capability.
  • the radio interface may comprise a radio modem 58 and radio frequency (RF) circuitries 52 providing at least a part of the above-described physical layer(s) of the wireless device.
  • the radio interface may be comprised in the apparatus in the embodiments where the apparatus is the wireless device.
  • the radio interface may be external to the apparatus.
  • the radio interface may support frame transmission and reception according to the principles described above.
  • the RF circuitries 52 may comprise radio frequency converters and components such as an amplifier, filter, and one or more antennas.
  • the radio modem 58 may comprise baseband signal processing circuitries such as (de)modulator and encoder/decoder circuitries.
  • the communication circuitry may carry out at least some of the functions of the MAC layer(s) described above.
  • the radio modem 58 and the RF circuitries 52 may employ a separate transmitter and receiver branch for each of the multiple links supported by the apparatus.
  • the radio modem 58 and the RF circuitries 52 may include a dedicated circuitry for the physical layer 136 and another dedicated circuitry for the physical layer 138, although the dedicated circuitries may employ partially the same physical components in the transmission and/or reception.
  • the communication circuitry 50 may comprise multiple channel sensing circuitries 54, 56, ... each configured to perform channel sensing on a channel.
  • the channel sensing circuitries 54, 56, ... may operate concurrently, as described above.
  • a channel sensing circuitry may operate the radio modem 58 and the RF components to tune into a respective channel to perform channel sensing in order to detect a frame on the respective channel or to perform channel contention on the respective channel.
  • the channel sensing circuitry may output a notification of the detection and, as a response, the communication circuitry 50 may enable a measurement circuitry 53 to measure the frame in the above-described manner, and/or enable a frame decoder 52 to decode at least the above-described first part of the frame.
  • the communication circuitry may then make the decision (block 202) of whether or not the frame decoder is able to complete the decoding of the frame.
  • the communication circuitry may monitor a status of a buffer 66 for high-priority uplink data. Such a high-priority data in the buffer may cause the communication circuitry to activate the radio modem to transmit the negative acknowledgement on one of the channels where the frame reception is not currently being performed and, further, activate a frame encoder to encode the high- priority data and prepare for transmission of the encoded data upon detecting the cancellation of the frame transmission.
  • the communication circuitry may configure the radio modem to transmit a respective negative acknowledgement with the appropriate reason code, as described above.
  • the frame decoder performs various types of decoding.
  • the radio modem may perform only synchronization to the received frame and perform sampling of the received frame. Thereafter, the frame decoder may perform the subsequent receiver signal processing functions such as demodulation, channel decoding, header extraction, decoding of header fields, etc.
  • the radio modem 58 may perform demodulation and channel decoding and other physical layer processing, and the frame decoder realizes the MAC layer decoding, e.g. extraction and decoding of MPDU field contents. Other implementations are equally possible.
  • the apparatus may further comprise an application processor 56 executing one or more computer program applications that generate a need to transmit and/or receive data through the communication circuitry 50.
  • the application processor may form an application layer of the apparatus.
  • the application processor may execute computer programs forming the primary function of the apparatus. For example, if the apparatus is a sensor device, the application processor may execute one or more signal processing applications processing measurement data acquired from one or more sensor heads. If the apparatus is a computer system of a vehicle, the application processor may execute a media application and/or an autonomous driving and navigation application.
  • the application processor may generate data to be transmitted in the wireless network.
  • the apparatus may further comprise a memory 60 storing one or more computer program products 62 configuring the operation of said processor(s) of the apparatus.
  • the memory 60 may further store a configuration database 64 storing operational configurations of the apparatus.
  • the configuration database 64 may store, for example, the responsibilities of the radio modem and the frame decoder, the threshold(s) described above, etc.
  • the memory 60 may further store the buffer 66.
  • Figure 10 illustrates an embodiment of a structure of the above-mentioned functionalities of an apparatus executing the functions of the apparatus in the process of Figure 3 or any one of the embodiments of Figure 3 described above.
  • the apparatus may be a wireless device such as the access node 110. In another embodiment where the above-described roles are reversed, the apparatus may be the terminal device 100.
  • the apparatus may comply with 802.11 specifications or specifications of another wireless network.
  • the apparatus may be or may be comprised in a computer (PC), a laptop, a tablet computer, a cellular phone, a palm computer, a sensor device, a router device, or any other apparatus provided with radio communication capability.
  • the apparatus carrying out the process of Figure 3 or any one of its embodiments is comprised in such a wireless device, e.g. the apparatus may comprise a circuitry, e.g. a chip, a chipset, a processor, a micro controller, or a combination of such circuitries in the wireless device.
  • the apparatus may be an electronic device comprising electronic circuitries for realizing some embodiments of the wireless device.
  • the apparatus may comprise a communication circuitry 10 providing the apparatus with capability of communicating in at least one wireless network.
  • the communication circuitry may employ a radio interface providing the apparatus with radio communication capability.
  • the radio interface may comprise a radio modem 18 and radio frequency (RF) circuitries 12 providing at least a part of the above-described physical layer(s) of the wireless device.
  • the radio interface may be comprised in the apparatus in the embodiments where the apparatus is the wireless device. In other embodiments where the apparatus is a chipset for the wireless device, the radio interface may be external to the apparatus.
  • the radio interface may support frame transmission and reception according to the principles described above.
  • the RF circuitries 12 may comprise radio frequency converters and components such as an amplifier, filter, and one or more antennas.
  • the radio modem 18 may comprise baseband signal processing circuitries such as (de)modulator and encoder/decoder circuitries.
  • the communication circuitry may carry out at least some of the functions of the MAC layer(s) described above.
  • the radio modem 18 and the RF circuitries 12 may employ a separate transmitter and receiver branch for each of the multiple links supported by the apparatus.
  • the communication circuitry 10 may comprise multiple channel sensing circuitries 14, 16, ... each configured to perform channel sensing on a channel, as described above in connection with Figure 9.
  • the channel sensing circuitries 14, 16, ... may operate concurrently, as described above.
  • a channel sensing circuitry may operate the radio modem 18 and the RF components to tune into a respective channel to perform channel sensing in order to detect a frame on the respective channel or to perform channel contention on the respective channel.
  • the channel sensing circuitry may output a notification of the detection and, as a response, the communication circuitry 50 may enable a frame decoder 52 to decode the frame and to extract the reason comprised in the negative acknowledgment.
  • the value of the information element indicating the reason may be output by the frame decoder and, depending on the value of the reason, any one of the above-described embodiments may be followed. Regardless of the reason, the communication circuitry may cancel the on-going transmission in the above-described manner. The reason maybe output to a parameter controller 13 that controls transmission parameters. The parameter controller may then change the transmission parameters for the subsequent retransmission. Depending on the value of the reason, the communication circuitry may, upon cancelling the transmission, instantly enable a frame encoder 11 to perform the retransmission during the on-going TXOP, as described above, but with different transmission parameters, as determined by the parameter controller 13.
  • the communication circuitry may enable a scheduler 19 to schedule the remaining resources of the TXOP to communication frame(s) with another device, as described above.
  • the communication circuitry may enable the encoder 11 to perform the retransmission in another TXOP.
  • the apparatus may further comprise a memory 20 storing one or more computer program products 22 configuring the operation of said processor(s) of the apparatus.
  • the memory 20 may further store a configuration database 24 storing operational configurations of the apparatus.
  • the configuration database 24 may store, for example, the actions resulting from each reason code of the negative acknowledgment message.
  • the memory 60 may further store a buffer 26 for data to be transmitted.
  • circuitry refers to one or more of the following: (a) hardware-only circuit implementations such as implementations in only analog and/or digital circuitry; (b) combinations of circuits and software and/or firmware, such as (as applicable): (i) a combination of processor(s) or processor cores; or (ii) portions of processor(s)/software including digital signal processor(s), software, and at least one memory that work together to cause an apparatus to perform specific functions; and (c) circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present.
  • circuitry applies to uses of this term in this application.
  • circuitry would also cover an implementation of merely a processor (or multiple processors) or portion of a processor, e.g. one core of a multi-core processor, and its (or their) accompanying software and/or firmware.
  • circuitry would also cover, for example and if applicable to the particular element, a baseband integrated circuit, an application- specific integrated circuit (ASIC), and/or a field-programmable grid array (FPGA) circuit for the apparatus according to an embodiment of the invention.
  • ASIC application- specific integrated circuit
  • FPGA field-programmable grid array
  • the processes or methods described in Figures 2 to 8 may also be carried out in the form of one or more computer processes defined by one or more computer programs.
  • a separate computer program may be provided in one or more apparatuses that execute functions of the processes described in connection with the Figures.
  • the computer program(s) may be in source code form, object code form, or in some intermediate form, and it may be stored in some sort of carrier, which may be any entity or device capable of carrying the program.
  • Such carriers include transitory and/or non- transitory computer media, e.g. a record medium, computer memory, read-only memory, electrical carrier signal, telecommunications signal, and software distribution package.
  • the computer program may be executed in a single electronic digital processing unit or it may be distributed amongst a number of processing units.
  • Embodiments described herein are applicable to wireless networks defined above but also to other wireless networks.
  • the protocols used, the specifications of the wireless networks and their network elements develop rapidly. Such development may require extra changes to the described embodiments. Therefore, all words and expressions should be interpreted broadly and they are intended to illustrate, not to restrict, the embodiment. It will be obvious to a person skilled in the art that, as technology advances, the inventive concept can be implemented in various ways. Embodiments are not limited to the examples described above but may vary within the scope of the claims.

Landscapes

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

Abstract

La présente invention concerne une solution d'accusé de réception de transmissions. Selon un aspect, un procédé pour un premier nœud de réseau d'un réseau sans fil comprend les étapes suivantes : réception d'une première partie d'un premier message sur un premier canal en provenance d'un deuxième nœud de réseau du réseau sans fil ; détermination, lors de la réception du premier message, que le premier nœud de réseau est dans l'incapacité de mener à bien le décodage du premier message ; en réponse à ladite détermination et tout en recevant le premier message, transmission sur un deuxième canal d'un message d'accusé de réception négatif au deuxième nœud de réseau, l'accusé de réception négatif comprenant au moins un élément d'information indiquant une raison pour laquelle le premier nœud de réseau est dans l'incapacité de mener à bien le décodage du premier message ; et réception d'une retransmission du premier message.
PCT/EP2020/064858 2020-05-28 2020-05-28 Accusé de réception de paquet dans un réseau sans fil WO2021239232A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/EP2020/064858 WO2021239232A1 (fr) 2020-05-28 2020-05-28 Accusé de réception de paquet dans un réseau sans fil

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/EP2020/064858 WO2021239232A1 (fr) 2020-05-28 2020-05-28 Accusé de réception de paquet dans un réseau sans fil

Publications (1)

Publication Number Publication Date
WO2021239232A1 true WO2021239232A1 (fr) 2021-12-02

Family

ID=70922038

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2020/064858 WO2021239232A1 (fr) 2020-05-28 2020-05-28 Accusé de réception de paquet dans un réseau sans fil

Country Status (1)

Country Link
WO (1) WO2021239232A1 (fr)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050249244A1 (en) * 2004-03-10 2005-11-10 Kabushiki Kaisha Toshiba Packet format

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050249244A1 (en) * 2004-03-10 2005-11-10 Kabushiki Kaisha Toshiba Packet format

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
FRAUNHOFER HHI ET AL: "Scheduling/HARQ Processing Timeline Enhancements for NR URLLC", vol. RAN WG1, no. Spokane, USA; 20181112 - 20181116, 11 November 2018 (2018-11-11), XP051555128, Retrieved from the Internet <URL:http://www.3gpp.org/ftp/Meetings%5F3GPP%5FSYNC/RAN1/Docs/R1%2D1813146%2Ezip> [retrieved on 20181111] *

Similar Documents

Publication Publication Date Title
US10111258B2 (en) Methods and systems for receiver initiated protection of a wireless communication exchange
EP2638656B1 (fr) Procédés permettant de réaliser une agrégation de canaux
US7650559B2 (en) Communication apparatus, communication system, communication method, and communication control program
EP2975883A1 (fr) Procédé de réalisation de commutation de canal dans un réseau faisant converger une pluralité de systèmes de communication et appareil associé
KR20170062455A (ko) 무선 네트워크에서 다중 사용자 업링크 매체 액세스 제어 프로토콜들을 구현하기 위한 방법들 및 장치
WO2015031044A1 (fr) Protocole de demande d&#39;émission (rts)/prêt à émettre (cts) adaptatif dans des communications sans fil hautement efficaces
US9609667B2 (en) Procedure for setting threshold for accessing channel
EP3357181A1 (fr) Messagerie multiplexée dans un réseau sans fil
KR20220006092A (ko) 패킷 도달 전 채널 경합
US20220150980A1 (en) Ue, network node and methods for handling 2-step and 4-step random access procedures
JP6793744B2 (ja) ワイヤレス通信ネットワークにおいて干渉を低減するための方法
US20190007971A1 (en) Terminal device, communication method, and integrated circuit
US20240031853A1 (en) Station apparatus and access point apparatus
JP7068115B2 (ja) 無線通信装置、無線通信方法およびプログラム
WO2022067748A1 (fr) Communications de liaison latérale dans un réseau sans fil
US20230180290A1 (en) Channel Sensing in Multi-Link Capable Wireless Device
WO2021239232A1 (fr) Accusé de réception de paquet dans un réseau sans fil
US20230199823A1 (en) Base station apparatus, terminal apparatus, and communication method
EP4042815B1 (fr) Détection de nouvelles opportunités de transmission
US20230284290A1 (en) Enhanced Multi-link UORA
US20240049187A1 (en) Trigger Frame for Uplink Resource Allocation
US20230199825A1 (en) Terminal apparatus, base station apparatus, and communication method
JP7136443B2 (ja) 無線通信装置、情報収集装置、無線通信方法、および情報収集方法
WO2018203904A1 (fr) Mécanisme de reprise sur incident à dispositif sans fil en veille
US20230345526A1 (en) Coexistence of devices in wireless network

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20729705

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20729705

Country of ref document: EP

Kind code of ref document: A1