Radio device, method of operating a radio device

Abstract

Radio device, method of operating a radio device. A method of operating a transmitting radio device of a radio communication network is provided, wherein the method comprises transmitting (102) first data towards a receiving radio device according to a first transmission mode, determining (104) a last reception time when a positive acknowledgement is received from the receiving radio device, the positive acknowledgement indicating a successful reception of the transmitted first data at the receiving radio device side, and transmitting (106) second data towards the receiving radio device according to a second transmission mode, wherein the second transmission mode is activated upon expiry of a first transmission mode time period since the determined last reception time.

Description

State of the art

[0001] The present invention relates to a radio device of a radio communication network and a method of operating the radio device.

[0002] In modern wireless communication systems, forward error correction (FEC) and automatic repeat request (ARQ) and / or hybrid automatic repeat request (HARQ) are used to ensure successful message reception in case of transmission errors (e.g. in case of channel errors or packet loss). With FEC, redundancy is added to the data payload, which can be used to correct messages at the receiver side up to a certain number of bit errors.

[0003] Recently, the term survival time has been proposed to be considered in the 5G specification, i.e. to take into account special requirements from time-critical industrial applications or from safety-critical automotive applications. SUMMARY

[0004] According to a first aspect of the present specification, there is provided a transmitting radio device of a radio communication network, in particular a cellular radio communication network, wherein the transmitting radio device comprises at least one processor, at least one memory including computer program code, at least one communication module, and at least one antenna, wherein the computer program code is configured to, with the at least one processor, the at least one communication module, and the at least one antenna, cause the transmitting radio device at least to transmit first data towards a receiving radio device according to a first transmission mode; determine a last reception time when a positive acknowledgement is received from the receiving radio device, the positive acknowledgement indicating a successful reception of the transmitted first data at the receiving radio device side; and transmit second data towards the receiving radio device according to a second transmission mode, wherein the second transmission mode is activated upon expiry of a first transmission mode time period since the determined last reception time.

[0005] Communication service reliability and communication service availability are a complement to the packet error rate. PER can be used to indicate the importance of individual packet loss, which for many industrial applications is different from the importance of losing several consecutive packets. For example, the loss of a single packet can only slightly degrade the quality of experience of an industrial application, while the loss of several consecutive packets is considered as a communication service unavailability, which potentially leads to an emergency stop in the application. On the one hand, the radio domain benefits by dividing the time in a first transmission mode and a second transmission mode, as the first transmission mode requires less resources. On the other hand, the application will benefit, as the second transmission mode will increase the probability of a successful transmission and avoid reaching the survival time.

[0006] Applications exchange data in a periodic manner, which means that a transmission of time-critical data is performed by the application with a certain periodicity. The requirement of the application is that at least one message is successfully delivered to the receiver (or all receivers) within a lifetime. For example, these applications occur in industrial communication systems or automotive applications (e.g. platooning). When the lifetime is about to be exceeded (which should be avoided), additional transmission resources are utilized to increase the probability of a successful end-to-end transmission, which means that a second transmission mode becomes aggressive as the lifetime expires.

[0007] A highly reliable data transmission is achieved. Before the lifetime is reached, appropriate actions are initiated according to the second transmission mode. With this approach, the stringent requirements of time-critical applications are addressed and the usage of transmission resources is optimized.

[0008] Thus, the communication service will have an increased quality of experience before becoming unavailable.

[0009] According to a second aspect of the present specification, a method of operating a transmitting radio device of a radio communication network, in particular a cellular radio communication network, is provided, wherein the method comprises transmitting first data towards a receiving radio device according to a first transmission mode; determining a last reception time when a positive acknowledgement is received from the receiving radio device, the positive acknowledgement indicating a successful reception of the transmitted first data at the receiving radio device side; and transmitting second data towards the receiving radio device according to a second transmission mode, wherein the second transmission mode is activated upon expiry of a first transmission mode time period since the determined last reception time.

[0010] According to a third aspect, a receiving radio device of a radio communication network, in particular a cellular radio communication network, is provided, wherein the receiving radio device comprises at least one processor, at least one memory including computer program code, at least one communication module, and at least one antenna, wherein the computer program code is configured to, with the at least one processor, the at least one communication module, and the at least one antenna, cause the receiving radio device at least to receive first data from a transmitting radio device; determine a last reception time when the first data is successfully received from the transmitting radio device; and transmit a second transmission mode indicator towards the transmitting radio device upon expiry of a first transmission mode time period since the determined last reception time.

[0011] A highly reliable data transmission is achieved. Before the lifetime is reached, appropriate actions are initiated according to the second transmission mode. With this approach, the stringent requirements of time-critical applications are addressed and the usage of transmission resources is optimized.

[0012] According to an advantageous example, the receiving radio device is configured to transmit a first transmission mode indicator towards the transmitting device upon successful reception of the second data from the transmitting device.

[0013] Advantageously, the receiving device controls the transmitting device to enter the first transmission mode upon successful reception of the data.

[0014] A fourth aspect of the present specification relates to a method of operating a receiving radio device of a radio communication network, in particular a cellular radio communication network, wherein the method comprises: receiving first data from a transmitting radio device; determining a last reception time when the first data is successfully received from the transmitting radio device; and transmitting a second transmission mode indicator towards the transmitting radio device upon expiry of a first transmission mode time period from the determined last reception time.

[0015] According to a fifth aspect, there is provided a transmitting radio device of a radio communication network, in particular a cellular radio communication network, wherein the transmitting radio device comprises at least one processor, at least one memory including computer program code, at least one communication module, and at least one antenna, wherein the computer program code is configured to, with the at least one processor, the at least one communication module, and the at least one antenna, cause the transmitting radio device at least to: transmit first data towards a receiving radio device according to a first transmission mode; receive a second transmission mode indicator from the receiving radio device; and transmit second data towards the receiving radio device according to a second transmission mode, wherein the second transmission mode is activated upon reception of the second transmission mode indicator.

[0016] According to an advantageous example, the transmitting radio device is configured to receive a first transmission mode indicator from the receiving device indicating that the transmitting device successfully received the second data; and upon reception of the first transmission mode indicator, transmit the first data towards the receiving radio device according to the first transmission mode.

[0017] A sixth aspect of the present specification provides a method of operating a transmitting radio device of a radio communication network, in particular a cellular radio communication network, wherein the method comprises: transmitting first data towards a receiving radio device according to a first transmission mode; receiving a second transmission mode indicator from the receiving radio device; and transmitting second data towards the receiving radio device according to a second transmission mode, wherein the second transmission mode is activated upon reception of the second transmission mode indicator.

[0018] A seventh aspect of the present specification provides a transceiving radio device of a radio communication network, in particular a cellular radio communication network, wherein the transceiving radio device comprises at least one processor, at least one memory including computer program code, at least one communication module, and at least one antenna, wherein the computer program code is configured to interact with the at least one processor, the at least one communication module, and the at least one antenna, to cause the transceiving radio device at least to receive first data from a transmitting radio device; transmit the first data to a receiving radio device; determine a last reception time when a positive acknowledgement is received from the receiving radio device, the positive acknowledgement indicating a successful reception of the transmitted first data at the receiving radio device side; and transmit a second transmission mode indicator towards the transmitting radio device upon expiry of a first transmission mode time period from the determined last reception time.

[0019] A highly reliable data transmission is achieved. Prior to reaching the survival time, appropriate actions are initiated according to the second transmission mode. With this approach, the stringent requirements of time-critical applications are addressed and the usage of transmission resources is optimized.

[0020] An eighth aspect of the present specification provides a method of operating a transceiving radio device of a radio communication network, the method comprising: receiving first data from a transmitting radio device; transmitting the first data to a receiving radio device; determining a last reception time when a positive acknowledgement is received from the receiving radio device, the positive acknowledgement indicating a successful reception of the transmitted first data at the receiving radio device side; and transmitting a second transmission mode indicator towards the transmitting radio device upon expiry of a first transmission mode time period from the determined last reception time.

[0021] An advantageous example provides that the first transmission mode time period is smaller than the sum of a survival time period of the application unit and a cycle time of the application unit, in particular half of the sum of the survival time period and the cycle time.

[0022] Advantageously, the application unit will perceive an increased data delivery success. Thus, the proposed solution protects the application unit from being shut down or entering a safe mode upon reaching the survival time period.

[0023] An advantageous example provides that the first transmission mode time period is greater than a cycle time period of the application unit, wherein the cycle time period indicates a periodic data provision by the application unit and a periodic data transmission towards the receiving radio device.

[0024] On the one hand, this way of selecting the first transmission mode time period will increase the availability of the communication service. On the other hand, the first transmission mode does not unnecessarily "flood" the radio domain with unnecessary copies of the same message or will immediately occupy radio resources.

[0025] Advantageous examples provide that the second transmission mode comprises at least one of: an increased number of retransmissions of the second data for which reception at the receiving radio device or the transceiving radio device was not successful; an increased number of blind retransmissions of the second data; a different modulation and coding scheme for the second data; and an increased number of allocated radio resources for the second data transmission compared to the first transmission mode.

[0026] Advantageously, these measures help to increase the reliability of the transmission before the time-to-live is reached.

[0027] Advantageous examples provide that a second transmission mode indicator is transmitted towards the scheduling unit in order to schedule additional resources for the second transmission mode.

[0028] Thus, the scheduling unit will schedule appropriate resources available in the second mode in order to increase the probability of transmission of the second data.

[0029] Advantageous examples provide that the application unit of the transmitting device adds the first and second data at one end of an egress queue of the control unit and the control unit of the transmitting device removes the first and second data from the other end of the queue in order to transmit the first and second data towards the receiving device.

[0030] Advantageously, if the queue is empty and the transmitting device enters the second transmission mode, data packets that were unsuccessfully transmitted previously are not repeated but the queue is monitored for new periodically arriving data to be transmitted. This reduces the transmission overhead during the first and second mode.

[0031] Figure 1 、 Figure 3 、 Figure 4 and Figure 6 each depict a schematic flow chart;

[0032] Figure 2 、 Figure 5 and Figure 7 each depict a schematic sequence chart;

[0033] Figure 8 、 Figure 9 、 Figure 10 and Figure 11 each schematically depict a radio communication network; and

[0034] Figure 12 depicts a structure of a radio device.

[0035] Figure 1A schematic flow chart for operating a transmitting radio device of a radio communication network, in particular a cellular radio communication network, is depicted. According to step 102, the transmitting radio device transmits first data towards a receiving radio device according to a first transmission mode. According to step 104, the transmitting device determines a last reception time when an acknowledgement was last received from the receiving radio device, wherein the acknowledgement indicates a successful reception of the transmitted first data at the receiving radio device side. According to step 106, the transmitting radio device transmits second data towards the receiving radio device RxDev according to a second transmission mode, wherein the second transmission mode is activated upon expiry of a first transmission mode time period since the determined last reception time.

[0036] Figure 2 A schematic sequence diagram for operating a transmitting radio device TxDev of a radio communication network RCN is depicted. According to step 102, the transmitting device TxDev, in particular a physical layer block PHY1, transmits first data p1, p2 towards a receiving radio device RxDev according to a first transmission mode m1.

[0037] According to step 202, an acknowledgement ACK (p1 ) is received from the receiving device RxDev. According to step 104, the TxDev determines a last reception time t1 when the acknowledgement ACK (p1 ) was received from the receiving radio device RxDev. The acknowledgement ACK (p1 ) indicates a successful reception of the transmitted first data p1 by a controller unit C2 of the receiving radio device RxDev.

[0038] The second transmission mode m2 is activated at a time point t2. The time point t2 indicates that a first transmission mode time period m1 t has elapsed since the time point t1. Thus, according to steps 106a, 106b, the transmitting radio device TxDev transmits second data p3 towards the receiving radio device RxDev according to a second transmission mode m2, wherein the second transmission mode m2 is activated upon expiry of the first transmission mode time period m1 t since the determined last reception time t1.

[0039] According to step 204, upon receiving an acknowledgement ACK (p3) from the receiving radio device RxDev for the data p3 transmitted in the second transmission mode m2, according to step 206, the transmitting radio device TxDev enters the first transmission mode m1.

[0040] ARQ Automatic Repeat Request comprises that after the first successful transmission in a period K, no repetition or a limited number of repetitions can be applied in the period K+1, in case of a transmission failure in said period K+1. In this period K+1, there is no risk of exceeding the survival time, for example if the sum of the survival time period and the period time is defined as twice the first transmission mode time. However, if the transmission in the period K+2 also fails, the survival time applied will be exceeded and the application will fail. To prevent this, according to the second transmission mode m2, in this period K+2 automatic repetition is enabled to ensure a successful transmission of the data p3.

[0041] At the transmitting radio device TxDev, a counter value (e.g. a timer unit TU) related to the first transmission mode ml, the second transmission mode m2 and the survival time is steadily incremented - which represents the time since the last successful transmission and is reset each time an ACK message for a successful reception of a PDU message is received from the receiving radio device RxDev. In case a NACK is received or the transmitting radio device TxDev does not receive a message at all (this also includes a missing ACK message), the counter value is not reset and continues to be incremented. The transmitting device TxDev changes its behavior depending on the current value of the timer unit TU. If the first transmission mode threshold ml t is reached, the second transmission mode m2 is activated to increase the reliability of the transmission and to ensure a successful packet transmission within the survival time.

[0042] According to an example, the parameters of the timer unit TU (like ml t and st) are configured via dedicated signaling (e.g. RRC signaling) or by higher layers (e.g. application layer). The timer unit TU can be passed by upper layers that trigger lower layer adaptive reliability mechanisms (e.g. increase diversity, packet duplication, etc.). Once the timer unit TU is passed, each procedure of these high reliability mechanisms has to utilize said counter for triggering. In the former case, no RRC configuration for configuring the parameters of the timer unit TU can be needed.

[0043] For example, the TxDev receives a packet in its buffer or egress queue and is ready to be transmitted at a time offset T_offset. Thus, the TxDev resets the timer to T = T_offset. After the TxDev sends the data, it starts continuously incrementing the counter of the timer unit TU. If the TxDev receives an ACK associated with the first transmitted data, the TxDev resets the timer T back to T = T_offset. If the first data fails to be decoded at the RxDev, the RxDev generates a negative acknowledgement (NACK) back to the TxDev. If the TxDev receives a NACK associated with the previously transmitted data packet (e.g. in period 2), or does not receive an ACK within a given duration (timer), the TxDev does the following: the TxDev triggers its reliability mechanism (related to increase of next packet duplication, HARQ retransmission, etc.) in the form of a second transmission mode m2. The TxDev further increments the TU timer.

[0044] The TxDev sends further data with reliability metrics in the third period according to the second transmission mode as above. If the data p3 is not correctly received and a NACK is generated by the RxDev and received by the TxDev, or p3 is correctly received and an ACK is transmitted but the TxDev does not correctly receive this ACK due to feedback channel error, HARQ precoding ambiguity, etc., a survival time period st is reached. In this case, the application APP1 of the TxDev indicates a system failure or initiates other resilience mechanisms.

[0045] Figure 3 A schematic flowchart for operating a receiving radio device of a radio communication network RCN is depicted. According to step 302, the receiving radio device receives first data from a transmitting radio device. According to step 304, the receiving radio device determines a last reception time when the first data was successfully received from the transmitting radio device. According to step 306, the receiving radio device transmits a second transmission mode indicator towards the transmitting radio device upon expiry of a first transmission mode time period from the determined last reception time.

[0046] Figure 4 A schematic flowchart for operating a transmitting radio device paired with Figure 3 a receiving radio device is depicted. According to step 402, the transmitting radio device transmits first data towards the receiving radio device according to a first transmission mode. According to step 404, the transmitting device receives a second transmission mode indicator from the receiving radio device RxDev. According to step 406, the transmitting radio device transmits second data towards the receiving radio device according to a second transmission mode, wherein the second transmission mode is activated upon reception of the second transmission mode indicator.

[0047] Figure 5 An exemplary sequence diagram is depicted. According to step 402, the transmitting radio device TxDev transmits first data p4, p5 towards the receiving radio device RxDev according to a first transmission mode ml.

[0048] According to step 304 of the method 300, the receiving radio device RxDev determines a last reception time tl when the first data p4 is successfully received from the transmitting radio device TxDev. According to step 306, the receiving radio device RxDev transmits a second transmission mode indicator m2i towards the transmitting radio device TxDev upon expiry of a first transmission mode time period ml t from the determined last reception time tl. Figure 3 According to step 404, the transmitting radio device TxDev receives the second transmission mode indicator m2i from the receiving radio device RxDev and enters a second transmission mode m2.

[0049] According to steps 406a, 406b, the transmitting radio device TxDev transmits second data p6 towards the receiving radio device RxDev according to the second transmission mode m2, wherein the second transmission mode m2 is activated upon reception of the second transmission mode indicator m2i. According to step 302, the receiving radio device RxDev receives the first data p4 from the transmitting radio device TxDev.

[0050] According to step 502, the receiving radio device RxDev transmits a first transmission mode indicator ml i towards the transmitting device TxDev upon successful reception of the second data p6 from the transmitting device TxDev.

[0051] According to step 502, the transmitting radio device TxDev receives the first transmission mode indicator ml i from the receiving device RxDev indicating successful reception of the second data p6 by the transmitting device TxDev. Upon reception of the first transmission mode indicator ml i, the transmitting radio device TxDev enters the first transmission mode.

[0052] Upon reception of the first transmission mode indicator ml i, the transmitting radio device TxDev transmits first data pi, p2 towards the receiving radio device RxDev according to the first transmission mode ml as in step 402.

[0053] Upon reception of the first transmission mode indicator ml i, the transmitting radio device TxDev transmits first data pi, p2 towards the receiving radio device RxDev according to the first transmission mode ml as in step 402.

[0054] The timer unit TU is implemented on the receiver side and triggers increased reliability in the form of a second transmission mode m2. RxDev is a device more prone to errors and failures when its lifetime is exceeded. As defined in industrial communication environments, the start / stop states of applications in the form of APP1 and APP2 are based on messages correctly received at RxDev. If packets / data are lost or not correctly received at RxDev, the communication service will enter a shutdown phase. If RxDev remains in the shutdown phase longer than its lifetime, it may notify higher levels to take appropriate action.

[0055] If a PDU message / data is successfully received, the counter value or timer of the timer unit TU is reset (to zero or another predetermined value). Once the maximum value in the form of m1t (e.g., a configured or pre-configured threshold) is reached, RxDev notifies TxDev to apply its second transmission mode to improve reliability and ensure successful packet reception before the time-to-live expires. After the next successful reception, at step 502, RxDev resets its local counter / timer and may signal the new status to TxDev.

[0056] As an example, RxDev sets a lower-level timer unit TU or a consecutive packet loss count M, after which RxDev declares a failure. The timer unit TU is configured by the network or passed on by the upper layer. The upper-layer pass (when the upper-layer timer T expires or a portion of its lifetime expires) requests RxDev to perform one or more of the following procedures: initiate more robust ACK / NACK transmission; notify TxDev of its running lifetime timer / counter and request more robust transmission, i.e., increased reliability as discussed above.

[0057] As an example, RxDev notifies TxDev of downtime in the communication service via more detailed ACK / NACK reports or more detailed CSI reports (including timer / counter information, etc.). In the case of direct communication between TxDev and RxDev regarding resource scheduling, RxDev instructs the base station and / or TxDev to provide detailed scheduling allocation / control channels, including timer / counter information, etc. Information regarding survival timers can be transmitted to TxDev. Possible robust transmissions / retransmissions (e.g., reduced MCS, duplication) can be transmitted to TxDev. Any repriorification of in-device transmission prioritization can be transmitted to TxDev.

[0058] According to the example, during ACK / NACK, a switching field is used to notify TxDev of the state of the timer unit TU. To keep track of ACK / NACK at TxDev and ensure that any ACK / NACK loss at TxDev is considered to avoid losing time-to-live information at RxDev, RxDev should: insert a 1-bit field into the ACK / NACK, such that this bit is switched each time RxDev sends an ACK or NACK. In this case: for example, if RxDev sends an ACK (where field = 0), the next one is a NACK (where field = 1), followed by an ACK (where field = 0), and then another ACK (where field = 1). Therefore, if TxDev misses the third feedback (ACK), it will also miss a field switch. However, if TxDev receives the subsequent ACK (fourth feedback), it will assume that the field has not switched. Therefore, TxDev can interpret this event as an ACK / NACK loss.

[0059] According to the example, a field with more than 1 bit is inserted into the ACK / NACK feedback. For example, a 2-bit field can be used, with 1 bit (e.g., LSB) indicating the switch and another bit (MSB) indicating the time within the lifespan timer, such as 0 indicating that the timer is in the first 1 / 2, the first 1 / 4, etc., and 1 indicating that the timer is in the last 1 / 2, 1 / 4 of the lifespan period and the cycle time.

[0060] As shown in the example, a 2-bit or more field is inserted into the ACK / NACK feedback to indicate the timer value or quantization value. For example, a 3-bit field can quantize 1 / 8 T of the timer; for instance, 000 = the first 1 / 8 T.

[0061] When the survival timer / counter expires, RxDev or TxDev should:

[0062] - As shown in the example, notify the higher layer of this event. The higher layer itself can enter safe mode or resilient mode, or the application can stop until recovery time, where the communication service can continue to listen for TX and wait for new commands or configurations.

[0063] - As an example, notify other participants in the communication (e.g., radio devices involved in the same communication) of the fault or recovery phase.

[0064] Figure 6A schematic flowchart of a transceiver radio device operating a radio communication network is depicted. According to step 602, the transceiver radio device receives first data from the transmitting radio device TxDev. According to step 604, the transceiver radio device transmits the first data to the receiving radio device. According to step 606, the transceiver radio device determines the last reception time when it receives a positive acknowledgment from the receiving radio device, the positive acknowledgment indicating successful reception of the transmitted first data at the receiving radio device. According to step 608, when the first transmission mode time period from the determined last reception time expires, the transceiver radio device transmits a second transmission mode indicator to the transmitting radio device.

[0065] Figure 7 A schematic sequence diagram is depicted. According to step 602, the transceiver radio TxRxDev receives first data p7 and p8 from the transmitting radio TxDev. According to step 604, the transceiver radio TxRxDev transmits the first data p7 and p8 to the receiving radio RxDev. However, the first data p8 is not received correctly, for example, it cannot be correctly decoded at the PHY unit PHY2 of the receiving radio RxDev.

[0066] According to step 606, the transceiver radio device TxRxDev determines the last reception time t1 when it receives a positive acknowledgment ACK (p7) from the receiving radio device RxDev, which indicates the successful reception of the transmitted first data p7 at the receiving radio device RxDev side.

[0067] According to step 608, when the first transmission mode time period m1t from the determined last reception time t1 expires, the transceiver radio device TxRxDev transmits a second transmission mode indicator m2i to the transmitting radio device TxDev.

[0068] The following content applies to Figures 1 to 7 Each example in the document.

[0069] At least one communication entity of the transmitting, receiving, or transceiver radio equipment TxDev, RxDev, TxRxDev includes a counter unit or timer unit TU or similar unit to measure the time up to the first transmission mode, the first transmission mode time period m1t, and the time up to the end of the lifetime.

[0070] This specification provides a method for increasing the reliability of time-critical data transmission during the lifetime of time-critical applications, including application units APP1 and APP2, while efficiently utilizing available transmission resources. Therefore, the data described herein can be referred to as time-critical data. However, the application tolerates a certain level of data loss.

[0071] In TS 22.104, lifetime is defined as "the time an application consuming a communication service can continue without the expected message." It has been identified as an impact factor for periodic deterministic communication (Table 5.2-1 in TS 22.104). Lifetime indicates to the communication service the available time to recover from a message delivery failure. Lifetime is expressed as a time period, particularly in the case of periodic traffic, that accommodates the maximum number of consecutive incorrectly received or lost messages that can be tolerated without causing application-layer failure.

[0072] According to the example, radio resources and radio parameters are allocated by a central coordination node (i.e., base station, access point, roadside unit). According to one example, a second transmission mode indicator m2i is additionally transmitted to the scheduling unit in order to schedule additional resources for the second transmission mode m2.

[0073] According to the example, radio resources are determined in a distributed manner, and each participating radio device can autonomously select the radio resources to use from the configured or pre-configured resources.

[0074] This time-critical application involves a transmitting radio device (TxDev) periodically transmitting time-critical data to one or more receiving radio devices (RxDev). The duration between two consecutive message transmissions is designated as the period time. The transmitted data includes redundancy to allow for forward error correction (up to a certain number of bit errors) and error detection of uncorrectable data.

[0075] According to the example, if the transmitting radio uses retransmission based on retransmission permission or autonomous retransmission, there is more than one transmission opportunity per transmission direction in each communication cycle.

[0076] As shown in the example, a time-critical stream / flow message is identified by sending the corresponding indicator along with the transmitted time-critical data.

[0077] According to the example, if at least one data message is correctly received and decoded within the lifetime, the application unit APP2 at the receiving radio device RxDev is considered to be working correctly. The lifetime exceeds the cycle time.

[0078] According to the example, the first transmission mode time period m1t is greater than the periodic time period k of application units APP1 and APP2, wherein the periodic time period k indicates the periodic data provision and periodic data transmission to the receiving radio device RxDev performed by application units APP1 and APP2.

[0079] According to the example, the first transmission mode time period m1t is less than the life period st of application units APP1 and APP2, especially half of the sum of the life period st and the cycle time period.

[0080] According to the example, compared with the first transmission mode m1, the second transmission mode m2 includes at least one of the following:

[0081] - Used to increase the number of retransmissions of second data that were not successfully received at the receiving radio device RxDev or the transceiver radio device TxRxDev, especially in the case of ARQ and ARQ;

[0082] - Used for increased blind retransmission of the second data;

[0083] - Different channel bandwidths, different bandwidth portions, different resource pools;

[0084] - Different modulation and coding schemes for the second data; and

[0085] - An increased amount of allocated radio resources used for the second data transmission;

[0086] - Packet replication (on another frequency resource, different technologies (e.g., different interfaces [through another sidechain or Uu interface], different radio access technologies, different frequency ranges (e.g., mm waves), or multiple connectivity).

[0087] The application unit APP1 of the transmission device TxDev adds first and second data at one end of the output queue of the control unit C1, and the control unit C1 of the transmission device TxDev removes the first and second data from the other end of the queue in order to transmit the first and second data toward the receiving device RxDev.

[0088] The process for establishing the described method includes:

[0089] 1. The master of time-critical application APP1 or APP2 establishes a time-critical and highly reliable communication flow from the management request of the communication system, for example, via an appropriate scheduling request to the base station unit. Such a request includes one of the following: the source and destination of the connection; the amount of data to be exchanged in each communication cycle; the cycle time of the data exchange; the lifetime of the application at RxDev; the identifier of the time-critical message to be recognized by the radio equipment of the wireless communication system; and a criticality metric. Configuration can be directed from, for example, the network via, for example, the base station to the radio equipment. Furthermore, configuration parameters (including one or more of the above) can be configured during setup, periodically, or on demand.

[0090] 2. Whether the management check of the wireless communication system (e.g., base station unit) can meet the required requests. Depending on the location of the RxDev and TxDev used for PDU connections within the network (at the network side or at the radio terminal) and the current network configuration, the management unit calculates parameters for the communication flow, which include at least one of the following: a unique identifier for the communication flow; identifiers of the source and destination of the PDU connection; the cycle time of the communication flow; the location of the timer unit TU used to measure the time since the last successful transmission; the method of signaling successful or unsuccessful transmission from the receiver to the transmitter (NACK); the method of signaling resource allocation (especially in the case of changes in reliability); a set of communication parameters with medium reliability and high efficiency (transmission mode m1) to be used when the lifetime is not about to be exceeded, and a set of communication parameters with high reliability and reduced efficiency (transmission mode m2) to be used when the lifetime is about to be exceeded; another set of communication parameters when the lifetime exceeds more than two communication cycle times and multiple levels of reliability (and efficiency); a threshold value for a counter indicating that the lifetime is about to be exceeded; a threshold value for a counter indicating that the lifetime has been exceeded; and details of the process in the case of the lifetime being exceeded.

[0091] 3. The management of the wireless communication system deploys these communication parameters to all inbound devices of the communication stream under consideration.

[0092] 4. The device applies the configuration parameters and responds to communication management if they are ready to continue.

[0093] 5. Once the communication management system receives positive confirmation from all the required devices, it replies to the application host that the time-critical and reliable flow has been established.

[0094] 6. Then, the application host notifies the PDU source (i.e., TxDev) to periodically send its time-critical data to RxDev. This step concludes the setup phase and enters the runtime phase.

[0095] The processes during the runtime operation of the provided data transmission scheme include:

[0096] 1. The application data source APP1 periodically generates time-critical data in the form of PDU messages, and forwards the PDU messages to its communication layer in the form of control unit C1.

[0097] 2. In TxDev, the communication layer, in the form of control unit C1, sends PDU messages to RxDev via the wireless channel according to the current communication settings (mode 1 compared to mode 2, etc.).

[0098] 3. RxDev checks whether the transfer has been successful.

[0099] 4. Upon successful reception, the PDU message is forwarded to the higher layers C2 and APP2. Figure 6 and Figure 7 In this scenario, the PDU message is forwarded to the PHY unit PHY3 of the second wireless section.

[0100] 5. If reception is not successful in the current communication cycle, a signal can also be sent to the higher-level APP1 and / or APP2.

[0101] 6. The transmission status is signaled to TxDev according to the configured method (ACK / NACK).

[0102] 7. The radio equipment incorporated into the timer unit TU continuously increments the counter value at a constant rate.

[0103] 8. A successful transmission of the event causes the counter value of the timer unit TU to be reset. If the counter is at RxDev, the internal signals of the device are sufficient. If the counter is at TxDev, a control message is transmitted toward RxDev.

[0104] 9. In each communication cycle, the counter value is compared with at least one configured threshold(s). If the threshold has been exceeded, the transmission mode is changed. If the value increments due to the absence of a successful reception, the threshold m1t is increased. If the value is reset from a value above the threshold m1t in the case of a successful reception, the threshold m1t is decreased. This change in transmission mode must be signaled to TxDev. If the counter is at TxDev, internal device signaling is sufficient. If the counter is at RxDev, a control message from the PDU receiver to the PDU transmitter is required.

[0105] 10. If a time-to-live threshold in the form of the sum of the time-to-live period st and the periodic time period is exceeded—which indicates an overrun of the time-to-live period—the radio device to which the timer unit TU is located may: notify both the communications management and the application host to trigger any process to recover the application from the failure state; or continue receiving according to its configured resources until communications are available again.

[0106] As periodic data exchange nears its end, the following should be implemented:

[0107] 1. The application host notifies TxDev to stop the periodic generation of data.

[0108] 2. The application host signals to the communications management system that radio resources for time-critical communication flows are no longer needed.

[0109] 3. The communication host reconfigures the incorporated devices: the counter value does not increment; the devices do not forward counter-related events; and any parameters related to the communication flow are disabled on the radio equipment.

[0110] Figure 8 The radio communication network RCN is depicted. Radio terminals RT1 and RT2 are configured as transmitting radio device TxDev and receiving radio device RxDev. Therefore, data transmission is indicated by arrow 800. The base station unit BS provides coverage within its provided cell C and schedules radio resources for radio terminals RT1 and RT2.

[0111] Figure 9 A radio communication network RCN is depicted. Radio terminal RT1 and base station unit BS are configured as transmitting radio device TxDev and receiving radio device RxDev. Therefore, for data transmission in the uplink direction, data transmission is indicated by arrow 900. Base station unit BS provides coverage in its provided cell C and schedules radio resources for radio terminals RT1 and RT2.

[0112] Figure 10 A radio communication network (RCN) is depicted. Base station unit (BS) and radio terminal RT1 are configured as transmitting radio device TxDev and receiving radio device RxDev. Therefore, for downlink data transmission, data transmission is indicated by arrow 1000. Base station unit BS provides coverage within its provided cell C and schedules radio resources for radio terminals RT1 and RT2.

[0113] Figure 11 A radio communication network (RCN) is depicted. Radio terminals RT1 and RT2 are configured as transmitting radio devices TxDev and receiving radio devices RxDev. A base station unit (BS) resides in the middle and acts as the transceiver radio device TxRxDev. Therefore, for uplink data transmission, data transmission is indicated by arrow 1102, and for downlink data transmission, data transmission is indicated by arrow 1104. The base station unit (BS) provides coverage within its assigned cell C and schedules radio resources for radio terminals RT1 and RT2.

[0114] Figure 12The structure of a wireless device is described, wherein the wireless device may be one of a transmitting wireless device TxDev, a receiving wireless device RxDev, and a transceiver wireless device TxRxDev. The wireless device includes at least one processor P, at least one memory M including computer program code CP, at least one communication module C, and at least one antenna A, wherein the computer program code CP is configured to interact with the at least one processor P, the at least one communication module C, and the at least one antenna A to cause the wireless device to perform the methods described above.

Claims

1. A transmit radio device (TxDev) for a radio communication network (RCN), wherein the transmit radio device (TxDev) includes at least one processor, at least one memory including computer program code, at least one communication module, and at least one antenna, wherein the computer program code is configured to interact with the at least one processor to cause the transmit radio device (TxDev) to at least: First data (p1; p2) is transmitted to the receiving radio device (RxDev) according to the first transmission mode (m1); Determine the first transmission mode time period (m1t) of the first transmission mode (m1), wherein, The first transmission mode time period (m1t) is greater than the periodic time period (k) and does not exceed the lifetime (st) of the transmitting radio device (TxDev), wherein the periodic time period (k) is based on the continuous transmission of the transmitting radio device (TxDev), and wherein the periodic time period (k) indicates periodic data provided by higher layers (APP1; APP2) and periodic data transmission toward the receiving radio device (RxDev); Determine the last reception time (t1) when a positive acknowledgment is received from the receiving radio device (RxDev); and According to the second transmission mode (m2), second data (p3) is transmitted toward the receiving radio device (RxDev), wherein the second transmission mode (m2) is activated when the first transmission mode time period (m1t) from the determined last reception time (t1) expires.

2. The transmitting wireless device (TxDev) according to claim 1, wherein, An acknowledgment that was not successfully transmitted occurs when a negative acknowledgment (NACK) is received or when a positive acknowledgment (ACK) is not received.

3. A method for operating a transmission radio device (TxDev) in a radio communication network (RCN), wherein the method comprises: First data (p1; p2) is transmitted to the receiving radio device (RxDev) according to the first transmission mode (m1); A first transmission mode time period (m1t) is determined for the first transmission mode (m1), wherein the first transmission mode time period (m1t) is greater than the periodic time period (k) and does not exceed the lifetime (st) of the transmitting radio device (TxDev), wherein the periodic time period (k) is based on the continuous transmission of the transmitting radio device (TxDev), and wherein the periodic time period (k) indicates periodic data provided by higher layers (APP1; APP2) and periodic data transmission toward the receiving radio device (RxDev); Determine (104) the last reception time (t1) when a positive acknowledgment is received from the receiving radio device (RxDev); and The second data (p3) is transmitted toward the receiving radio device (RxDev) according to the second transmission mode (m2), wherein the second transmission mode (m2) is activated when the first transmission mode time period (m1t) from the determined last reception time (t1) expires.

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