System and method for transmitting primary and secondary data in a communication network

Abstract

A system for transmitting primary and secondary data, the system comprising: a bus; a parent node coupled to the bus; and a plurality of child nodes each coupled to the bus, wherein: the parent node is configured to periodically transmit a time-domain multiplexing (TDM) periodic beacon to the bus, wherein the TDM periodic beacon signals the start of a primary data transmission interval, and wherein the primary data transmission interval is a period reserved for the transmission of primary data by the parent node and the plurality of child nodes; each of the parent node and the plurality of child nodes is operable to transmit primary data of a current TDM beacon period associated with the TDM periodic beacon to the bus during the primary data transmission interval in response to the TDM periodic beacon; and the parent node and the plurality of child nodes are operable to transmit secondary data to the bus during a secondary data transmission interval between the end of the primary transmission interval and the transmission of the next TDM periodic beacon by the parent node.

Description

Technical Field

[0001] This invention relates to a system and method for transmitting primary and secondary data in a communication network. Background Technology

[0002] Embedded electronic systems are increasingly used in various industrial applications. These applications can benefit from relatively simple, integrated, and low-latency communication systems that offer improved efficiency and ease of use in installing, using, and maintaining such systems. Summary of the Invention

[0003] According to a first aspect, the present invention provides a system for transmitting primary data and auxiliary data, the system comprising: a bus; a parent node coupled to the bus; and a plurality of child nodes each coupled to the bus, wherein: the parent node is configured to periodically transmit a time-domain multiplexing (TDM) periodic beacon to the bus, wherein the TDM periodic beacon signals the start of a primary data transmission interval, and wherein the primary data transmission interval is a period reserved for the transmission of primary data by the parent node and the plurality of child nodes; each of the parent node and the plurality of child nodes is capable, in response to the TDM periodic beacon, transmitting primary data of a current TDM beacon period associated with the TDM periodic beacon to the bus during the primary data transmission interval; and the parent node and the plurality of child nodes are operable to transmit auxiliary data to the bus during an auxiliary data transmission interval between the end of the primary transmission interval and the transmission of the next TDM periodic beacon by the parent node.

[0004] Primary data can have a higher priority than secondary data.

[0005] The primary data can be isochronous data associated with the first delay requirement. Auxiliary data can be associated with the second delay requirement. The first delay requirement can be more stringent than the second delay requirement.

[0006] The parent node can also be configured as a transmission data cycle beacon instead of a TDM cycle beacon, where the data cycle beacon signals the start of the primary data transmission interval and the start of the secondary data frame cycle, where the secondary data frame cycle provides the parent node and each of the multiple child nodes with the opportunity to transmit an secondary data frame to the bus.

[0007] Primary data may include audio data. Secondary data may include Ethernet data.

[0008] The parent node can be configured to transmit a TDM periodic beacon during each audio data sampling period.

[0009] TDM periodic beacons may include a first specific combination of symbols used in 10Base-T1S Ethernet.

[0010] Each of the parent node and multiple child nodes can be configured to transmit its primary data in the corresponding primary data microframe.

[0011] The primary data microframe may include: a header; one or more primary data samples for the current TDM beacon period; and a frame end delimiter.

[0012] The main data microframes may also include a scrambler synchronization sequence.

[0013] The header may include a second specific combination of symbols used in 10Base-T1S Ethernet.

[0014] The parent node and multiple child nodes can each be configured to transmit their respective primary data microframes in a predefined primary data transmission order.

[0015] Parent nodes and multiple child nodes can be configured to achieve minimal latency between the transmission of TDM periodic beacons and the transmission of the parent node's main data frames, as well as between the transmission of their respective main data microframes in a predefined main transmission order.

[0016] Parent nodes and multiple child nodes can be configured to implement random or pseudo-random delays between the transmissions of their respective primary microframes.

[0017] Each of the parent node and multiple child nodes is operable to determine the correct point in the main data transmission interval for transmitting its main data microframe by determining the following: the byte or time offset from the TDM periodic beacon; or the number of transmissions that have occurred on the bus since the transmission of the TDM periodic beacon.

[0018] If the parent node and each of the multiple child nodes have no auxiliary data frames to transmit, they can operate to transmit a yield signal to the bus.

[0019] The auxiliary data frame period can provide a corresponding transmission opportunity window for each of the parent node and multiple child nodes, within which either the parent node or the child node can transmit an auxiliary data frame to the bus. Each of the parent node and multiple child nodes can operate independently to maintain the correct timing of the transmission of its corresponding auxiliary data frame.

[0020] The auxiliary data frame period can provide a corresponding transmission opportunity window for each of the parent node and a plurality of child nodes, within which either the parent node or the child node can transmit an auxiliary data frame to the bus. Each of the parent node and the plurality of child nodes can include a transmission opportunity counter, which operates to count transmission opportunities since the transmission of the data period beacon. Each of the plurality of child nodes can determine when to transmit its corresponding auxiliary data frame based on the value of its corresponding transmission opportunity counter. Each of the parent node and the plurality of child nodes is operable to adjust its corresponding transmission opportunity counter in response to the transmission of an auxiliary data frame by either the parent node or a child node. If none of the plurality of child nodes has an auxiliary data frame to transmit, the child node is operable to not transmit a signal to the bus. The parent node is operable to transmit a transmission opportunity increment signal to the bus when it detects that the transmission opportunity window has passed without an auxiliary data frame being transmitted. Each of the plurality of child nodes is operable to adjust its corresponding transmission opportunity counter in response to the detection of the transmission opportunity increment signal.

[0021] If the transmission opportunity window will pass within a predefined time period before the scheduled transmission of the next TDM cycle beacon, the parent node can operate to delay the transmission of the transmission opportunity increment signal until after the main data transmission interval of the next TDM cycle period associated with the next TDM cycle beacon has ended.

[0022] The parent node can operate to transmit a new data cycle beacon instead of the next TDM cycle beacon in response to its transmission opportunity counter reaching a predefined value, instead of transmitting the transmission opportunity increment signal.

[0023] Data periodic beacons may include a third specific combination of symbols used in 10Base-T1S Ethernet.

[0024] If the length of the auxiliary data frame is greater than the length of the auxiliary data transmission interval, the node transmitting the auxiliary data frame is operable to segment the auxiliary data frame within a multi-TDM beacon period.

[0025] A node transmitting auxiliary data frames can operate to: suspend the transmission of auxiliary data frames; and resume the transmission of auxiliary data frames after the main transmission period of the next TDM beacon period has ended.

[0026] Nodes transmitting auxiliary data frames can operate to pause the transmission of auxiliary data frames on their octet boundaries.

[0027] A node transmitting auxiliary data frames is operable to: transmit a pause signal comprising a fourth specific symbol combination used in 10Base-T1S Ethernet to indicate the pause of auxiliary data frame transmission; and transmit a recovery signal comprising a fifth specific symbol combination used in 10Base-T1S Ethernet during the next TDM beacon period to indicate the resumption of auxiliary data frame transmission.

[0028] The parent node and multiple child nodes can be configured to implement random or pseudo-random delays in the transmission timing of their respective auxiliary data frames.

[0029] The parent node can operate to apply random or pseudo-random delays to the transmission of TDM beacon signals.

[0030] The parent node can operate to associate a randomized value indicating the duration of a random or pseudo-random delay with a TDM beacon signal.

[0031] Random or pseudo-random delays can be based on random probability density functions (RPDF) or triangular probability density functions (TPDF) with variable amplitude.

[0032] At least one of the parent node and / or multiple child nodes may include a clock recovery system configured to generate a clock signal based on a TDM periodic beacon signal and / or a data periodic beacon.

[0033] A clock recovery system can be configured to generate a TDM periodic beacon detection signal in response to the detection of a TDM periodic beacon or a data periodic beacon. The clock recovery system may include a phase-locked loop (PLL) configured to use the TDM periodic beacon detection signal as a frequency and phase reference to generate a clock signal.

[0034] Communication networks can include multi-point communication networks.

[0035] The bus may include twisted-pair cables.

[0036] The bus can be configured to transmit power to one or more of its child nodes.

[0037] According to a second aspect, the present invention provides a road noise cancellation system, the road noise cancellation system comprising the system of the first aspect, wherein at least one of a plurality of sub-nodes includes a microphone node or an accelerometer node, and wherein the main data includes road noise cancellation audio sample data generated by the microphone node or accelerometer data generated by the accelerometer node.

[0038] According to a third aspect, the present invention provides a method for transmitting primary data and auxiliary data in a communication network, the communication network including a bus, a parent node coupled to the bus, and a plurality of child nodes coupled to the bus, the method comprising: periodically broadcasting a TDM periodic beacon signal by the parent node, the TDM periodic beacon signal defining the start of a primary data transmission interval, wherein the primary data transmission interval is a period reserved for the transmission of primary data by the parent node and the plurality of child nodes; transmitting primary data to the bus during the primary data transmission interval in response to the TDM periodic beacon signal; and providing an auxiliary data transmission interval between the expiration of the primary data transmission interval and the broadcast of the next TDM periodic beacon signal by the parent node, the auxiliary data transmission interval being a period reserved for the transmission of auxiliary data by the parent node and / or the plurality of child nodes.

[0039] According to a fourth aspect, the present invention provides an isochronous data transceiver for a node in a system of the first aspect, wherein the isochronous data transceiver includes: processing circuitry implementing a framing engine, the framing engine including a primary data microframe processor and an auxiliary data frame processor; and interface circuitry for interfacing the isochronous data transceiver with a bus of the system, wherein: the primary data microframe processor is configured to transmit primary data microframes to and receive primary data microframes from the bus via the interface circuitry; the auxiliary data frame processor is configured to transmit auxiliary data frames to and receive auxiliary data frames from the bus via the interface circuitry; and the framing engine is operable to generate TDM periodic beacons and transmit them to the bus.

[0040] An isochronous data transceiver can be configured to receive TDM periodic beacons and / or data periodic beacons, and generate a clock signal based on the TDM periodic beacon signal and / or data periodic beacon signal.

[0041] Isochronous data can include audio data.

[0042] According to a fifth aspect, the present invention provides an integrated circuit (IC) that implements the isochronous data transceiver of the fourth aspect.

[0043] ICs can also include amplifier circuits.

[0044] According to a sixth aspect, the present invention provides a parent node or child node of a communication network, the communication network including an isochronous data transceiver according to a fourth aspect.

[0045] According to a seventh aspect, the present invention provides an integrated circuit that integrates a parent node of the system of the first aspect, wherein the integrated circuit operates to: apply a random or pseudo-random delay to the transmission of a TDM beacon signal; and associate a randomized value indicating the duration of the random or pseudo-random delay with the TDM beacon signal.

[0046] According to an eighth aspect, the present invention provides an integrated circuit that integrates a sub-node of the system of the first aspect, wherein the integrated circuit operates to: receive a TDM beacon signal having a random or pseudo-random delay and an associated randomization value; and, based on the received TDM beacon signal, use the randomization value to generate a reference clock signal to compensate for the random or pseudo-random delay of the beacon signal.

[0047] According to a ninth aspect, the present invention provides a vehicle comprising the system of the first aspect.

[0048] Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising”, shall be understood to mean including the stated element, integer or step, or group of elements, integers or steps, but not excluding any other element, integer or step, or group of elements, integers or steps. Attached Figure Description

[0049] Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 This is a schematic diagram of an example multipoint communication network in which the systems and methods of this disclosure can be implemented; Figure 2 It is used in Figure 1 A schematic diagram of a beacon-based transmission scheme for transmitting primary and secondary data in an example multipoint communication network 100; Figure 3a It shows Figure 2 A schematic diagram of an example structure of TDM periodic beacons and main data microframes used in a beacon-based transmission scheme; Figure 3b Multi-rate main data microframes are shown; Figure 4 yes Figure 2 A schematic diagram of a beacon-based transmission scheme, illustrating the transmission of auxiliary and primary data; Figure 5a yes Figure 2 A schematic diagram of a beacon-based transmission scheme, illustrating the transmission of auxiliary data frames within multiple beacon intervals; Figure 5bAn auxiliary data frame is shown that is transmitted in the same manner as a 10Base-T1S / IEEE802.3cg compatible Ethernet frame; Figure 5c The transmission of a portion of auxiliary data frames using a combination of pause and resume symbols is shown; Figure 6 yes Figure 2 A schematic diagram of a beacon-based transmission scheme, showing a transmission opportunity window in which no auxiliary data frames are transmitted; Figure 7 This is a schematic diagram illustrating how to recover the audio sampling clock from a transmitted TDM beacon; Figure 8 It can be used Figure 1 A schematic diagram of an audio transceiver system in a node of a multipoint communication network; Figure 9 yes Figure 8 A schematic diagram illustrating the implementation of an audio transceiver integrated circuit in an audio transceiver system; Figure 10 yes Figure 8 A schematic diagram of the combined amplifier and audio transceiver integrated circuit implementation of an audio transceiver system; Figure 11 This is a schematic diagram of the integrated circuit that implements the parent node; and Figure 12 This is a schematic diagram of an integrated circuit that implements a child node. Detailed Implementation

[0050] An example of an application where a relatively simple, integrated, and low-latency communication system could be beneficial is in embedded electronic systems in vehicles, such as multi-speaker audio or infotainment systems.

[0051] Such systems can be used to transmit audio signals representing music or other audio content from a central node to remote speakers. They can also be used for other purposes, such as road noise cancellation.

[0052] In a road noise cancellation (RNC) system, one or more microphone nodes (each node including a microphone and associated electronic circuitry (e.g., signal processing circuitry, analog-to-digital converter circuitry, network interface circuitry, etc.)) and one or more accelerometer nodes (each node including an accelerometer and associated electronic circuitry (e.g., signal processing circuitry, network interface circuitry, etc.)) are positioned near road noise sources within the vehicle area, such as in the area near the vehicle's wheels. The microphone nodes transmit audio signals representing detected road noise to a central node. The accelerometer nodes transmit accelerometer data signals representing detected vibrations or other motions to the central node. The central node generates a noise cancellation signal for each area of ​​the vehicle and transmits the noise cancellation signal to one or more speakers in the corresponding area of ​​the vehicle for output by the speakers. In this way, the perception of road noise by vehicle occupants can be reduced.

[0053] Systems such as RNC require very low latency audio and accelerometer data signal paths because the time required for the noise-canceling signal to be generated and transmitted to the relevant speakers must be shorter than the time required for sound to travel from the road noise source to the ears of the vehicle occupants.

[0054] Some vehicle audio systems use known Ethernet data transmission protocols to transmit audio signals over the in-vehicle Ethernet network. However, for RNCs, the latency of existing Ethernet data transmission protocols is too high to effectively eliminate or reduce road noise.

[0055] Similar considerations can also be applied to other applications that require low-latency data transmission, such as so-called "drive-by-wire" systems, where control signals used to control the operation of vehicle systems (such as throttle, steering, or braking systems) can be transmitted via an in-vehicle network.

[0056] Therefore, aside from lower-priority auxiliary data with less stringent latency requirements (such as control signals for body and cabin electronic functions like lighting control, seat control, heating, ventilation and air conditioning (HVAC) control, and window actuators), it is desirable to provide a communication system for transmitting high-priority primary data with low latency (such as RNC or drive-by-wire control signals). Allowing auxiliary data to be transmitted through the same communication system as the primary data allows for reduced weight and complexity compared to an arrangement providing a first communication system for primary data and a second, separate communication system for auxiliary data.

[0057] The systems and methods disclosed herein provide such a communication system.

[0058] Figure 1 This is a schematic diagram of an example multipoint communication network in which the systems and methods of this disclosure can be implemented.

[0059] exist Figure 1 The example multipoint communication network shown in the figure (approximately 100 Mbit / s) is a single-pair 10 Mbit / s multipoint network carrying primary and secondary data. The primary data has a higher priority than the secondary data. It should be understood that the example described herein uses a 10 Mbit / s network, but the principles of this disclosure are equally applicable to networks operating at different data rates. For example, the inventors envision that the principles of this disclosure can also be applied to networks operating at 100 Mbit / s or even higher data rates.

[0060] exist Figure 1 In the example, the primary data includes audio data (e.g., RNC audio data) with a first latency requirement, and the secondary data includes 10Base-T1S Ethernet data with a second latency requirement, which is more lenient than the first latency requirement. For example, the primary data may need to have a latency in the range of 100–200µs, while the secondary data may only need to have a latency in the range of 1–3ms.

[0061] Example multipoint communication network 100 includes network parent node 110 (also referred to as first node or node 0), in this example, the network parent node includes in-vehicle infotainment electronic control unit (IVI ECU).

[0062] The multipoint communication network 100 also includes multiple network sub-nodes. In this example, the multiple network sub-nodes include amplifier node 130 (which may be referred to as the second node or node 1), first microphone node 150A (which may be referred to as the third node or node 2), second microphone node 150B (which may be referred to as the fourth node or node 3), accelerometer node 170 (which may be referred to as the fifth node or node 4), and bridging node 180 (which may be referred to as the sixth node or node 5).

[0063] Each of the parent node 110 and multiple child nodes 130–180 is coupled to a network bus 190, which may include, for example, a network cable, such as a single twisted-pair cable. The network bus 190 may be, for example, a 10 Mbit / s Ethernet bus. The network bus 190 is configured to carry data and may also be configured to transmit power to one or more of the child nodes 130–180.

[0064] Parent node 110 and multiple child nodes 130–180 are coupled to network bus 190 in a multipoint configuration. In this multipoint configuration, data transmission is essentially half-duplex. All nodes 110–180 can receive any data transmitted from any node 110–180 to network bus 190. The advantages of using this multipoint configuration include: lower cabling costs, as multiple devices in a single area (e.g., a single area of ​​a vehicle) can be coupled to a single wireform consisting of multiple connectors crimped (or otherwise electrically connected) to a single twisted-pair cable; lower connector costs, both at network nodes and in the wireform; only one physical layer (PHY) interface is needed per node instead of two; only one set of electromagnetic compatibility (EMC) and power coupling filters is needed instead of two; and daisy-chain physical topology is supported without incurring forwarding delay per node.

[0065] Parent node 110 includes a PHY interface 112 for coupling parent node 110 to network bus 190. PHY interface 112 may be, for example, a 10 Mbit / s PHY interface. Similarly, each of child nodes 130–180 includes a corresponding PHY interface 132, 152, 172, 182 for coupling the child node to network bus 190.

[0066] The parent node 110 also includes a system-on-a-chip (SoC) 114, an Ethernet switch 116, protocol logic 118, and a phase-locked loop (PLL) 120.

[0067] SoC 114 is configured to receive digital audio data indicating detected road noise transmitted by a first microphone node 150A and a second microphone node 150B, and digital accelerometer data transmitted by an accelerometer node 170, and to generate digital road noise cancellation audio signals based on the digital audio data and the digital accelerometer data, which are transmitted by the parent node 110 to the amplifier node 130 via a network bus 190.

[0068] Ethernet switch 116 operates to transmit auxiliary data between SoC 114 and protocol logic 118. Protocol logic 118 operates to encapsulate audio data into data microframes suitable for transmission on the network bus via PHY interface 112, and decapsulates received data microframes to extract audio data. Protocol logic 118 further operates to encapsulate any Ethernet data (e.g., control data) received from Ethernet switch 116 into Ethernet packets suitable for transmission on network bus 190 via PHY interface 112, and decapsulates received Ethernet frames to extract Ethernet data for use by SoC 114, in a manner familiar to those skilled in the art. PLL 120 provides a clock reference signal for the audio data.

[0069] Amplifier node 130 is configured to receive a digital road noise cancellation audio signal transmitted by parent node 110. Based on the received digital road noise cancellation audio signal, amplifier node 130 operates to generate a road noise cancellation audio signal and outputs it to one or more internal speakers of the host vehicle incorporated into the multipoint communication network 100, in order to reduce the perception of road noise by the occupants of the host vehicle.

[0070] For this purpose, amplifier node 130 includes protocol logic 134, PLL 136, microcontroller 140, and amplifier circuitry 142. Protocol logic 134 operates to decapsulate received data microframes to extract audio data. PLL 136 is configured to provide a clock reference signal to amplifier circuitry 142. PLL 136 is also configured to receive signals from protocol logic 134 to synchronize the phase and frequency of its output. The signals received by PLL 136 from protocol logic 134 are derived from signals received by amplifier node 130 via bus 190, such as TDM or data periodic beacons of the type described below. Microcontroller 140 is coupled to protocol logic 134 via a bidirectional serial peripheral interface (SPI), enabling microcontroller 140 to transmit and receive auxiliary data for configuration and status purposes via the SPI interface.

[0071] First microphone node 150A and second microphone node 150B each include protocol logic 154, PLL 156, analog-to-digital converter (ADC) 158, and microphone 160. Microphone 160 operates to generate an analog audio output signal indicating road noise in this example. ADC 158 operates to convert the analog audio output signal generated by microphone 160 into a digital audio signal. This digital audio signal is output to protocol logic 154, which operates to encapsulate the digital audio signal into a primary data microframe suitable for transmission on network bus 190 via PHY interface 152 of microphone nodes 150A, 150B. PLL 156 is configured to provide a clock reference signal to ADC 158. PLL 156 is also configured to receive signals from protocol logic 154 to synchronize the phase and frequency of its output. The signal received by PLL 156 from protocol logic 134 is derived from the signal received by the corresponding microphone nodes 150A, 150B via bus 190, such as TDM or data periodic beacons of the type described below.

[0072] Accelerometer node 170 includes protocol logic 174, a phase-locked loop (PLL) 176, and an accelerometer 178. Accelerometer 178 generates a digital accelerometer output signal and outputs it to protocol logic 174, which operates to encapsulate the digital accelerometer output signal into a primary data microframe suitable for transmission on network bus 190 via PHY interface 172 of accelerometer node 170. PLL 176 is configured to provide a clock reference signal to accelerometer 178. PLL 176 is also configured to receive signals from protocol logic 174 to synchronize the phase and frequency of its output. The signals received by PLL 176 from protocol logic 174 are derived from signals received by accelerometer node 170 via bus 190, such as TDM or data periodic beacons of the categories described below.

[0073] The bridging node 180 includes protocol logic 184, an Ethernet bridge 186, and a second PHY interface 188. The second PHY interface 188 may be, for example, a 10Base-T1S PHY interface, used to bridge auxiliary Ethernet data received via network bus 190 to other local Ethernet devices.

[0074] Reference Figure 1 The methods and systems of this disclosure are described using an example multipoint communication network 100, but those skilled in the art should understand that the methods and systems of this disclosure are equally suitable for other applications where the transmission of primary and secondary data in a communication network is necessary or desirable.

[0075] Figure 2 It is used in Figure 1This is a schematic diagram of a beacon-based transmission scheme for transmitting primary and secondary data in an example multipoint communication network 100. Figure 1 In the example, the primary data includes low-latency audio and accelerometer data, and the secondary data includes Ethernet data, such as Ethernet control data.

[0076] exist Figure 2 In the transmission scheme shown, parent node 110 operates by periodically broadcasting or transmitting a first beacon signal 202, also known as a time-division multiplexing (TDM) periodic beacon, to network bus 190. Figure 1 In the example multipoint communication network 100, the TDM periodic beacon 202 is transmitted once by the parent node 110 within each audio sampling period. For example, if an 8 kHz sampling rate is used for the audio signal in network 100, the TDM periodic beacon 202 is transmitted once every 125 µs. More generally, the TDM periodic beacon 202 is transmitted once by the parent node 110 within each TDM beacon period, such that in Figure 1 In the example, the TDM beacon period is equal to the duration of the audio sampling period, which is 125µs.

[0077] TDM periodic beacon 202 uses a signal to indicate or define the start of the main data transmission interval 210. The main data transmission interval 210 is a reserved time slot for transmitting main data (e.g., audio samples) from nodes 110-180 to network bus 190.

[0078] exist Figure 1 In the example network 100, each node 110–180 has a pre-configured number of transmission channels for transmitting primary data to the network bus 190.

[0079] For example, parent node 110 may have first and second ECU transmission channels, each including audio data samples. These ECU transmission channels transmit to network bus 190 in ECU data microframes 212. First microphone node 150A and second microphone node 150B may each have a corresponding single audio transmission channel for audio data samples, and these microphone transmission channels transmit to network bus 190 in corresponding first microphone data microframes 216 and second microphone data microframes 218. Accelerometer node 170 may have first, second, and third transmission channels for accelerometer data samples, and these accelerometer transmission channels transmit to network bus 190 in accelerometer data microframes 222. In this example, amplifier node 130 and bridge node 180 do not have transmission channels because they do not transmit primary data to network bus 190.

[0080] During the primary data transmission interval 210, each of the parent node 110 and child nodes 130–180 transmits data samples from its transmission channel for the current sampling period to the network bus 190 according to a predefined primary data transmission order. Figure 2 In the example shown, the predefined primary data transmission order is: parent node 110, first microphone node 150A, second microphone node 150B, and accelerometer node 170. The transmission channels for each node 110–180 with data samples to be transmitted transmit data in corresponding data microframes, as detailed below. Figure 3a To explain its structure.

[0081] Therefore, in Figure 2 In the example shown, immediately following the TDM beacon 202 transmission, the parent node 110 transmits data samples from its first and second ECU transmission channels for the current audio sampling period to the network bus 190 during the main data transmission interval 210. Data samples from the first ECU transmission channel 212 and the second ECU transmission channel 214 are transmitted in ECU data microframes 212.

[0082] After transmitting ECU data microframe 212 containing data samples of the first and second ECU transmission channels, the first microphone node 150A transmits first microphone data microframe 216 containing data samples of its audio transmission channels during the current video sampling period to the network bus 190.

[0083] Then, the second microphone node 150B transmits the second microphone data microframe 218, which contains data samples of its audio transmission channel during the current audio sampling period, to the network bus 190.

[0084] Then, accelerometer node 170 transmits accelerometer data microframe 222, which contains data samples of its first, second, and third transmission channels during the current audio sampling period, to network bus 190.

[0085] Immediately following the TDM periodic beacon 202, a main data transmission interval 210 is provided to ensure that data samples from each node within the current audio sampling period are transmitted to the network bus 190 within a single TDM beacon period. Therefore, within the same single TDM beacon period, each node 110–190 coupled to the network bus 190 can receive the transmitted data samples. This ensures that the network bus 190 transmits data samples with a delay not exceeding one video sampling period.

[0086] Figure 3a This is a schematic diagram showing an example structure of a TDM periodic beacon 202 and a data microframe containing data samples from nodes 110–180.

[0087] exist Figure 3a In the example shown in general at 300, the TDM periodic beacon 202 is followed by a sequence of major data microframes, which includes a first major data microframe 310 transmitted by the parent node (node ​​0) 110, a second major data microframe 320 transmitted by the first child node (node ​​1), and a third major data microframe 330 transmitted by the second child node (node ​​2).

[0088] TDM periodic beacon 202 includes a first specific combination of four symbols from the 5-bit symbolic alphabet used in the Physical Coding Sublayer (PCS) of 10Base-T1S Ethernet (as defined by the IEEE Std 802.3cg-2019 standard). TDM periodic beacon 202 uses the same signaling as 10Base-T1S Ethernet, providing good electromagnetic compatibility (EMC) and signal integrity. The first specific combination of symbols used in TDM periodic beacon 202 signals the start of a major data transmission interval for transmitting primary data to other nodes coupled to network bus 190. To ensure that TDM periodic beacon 202 explicitly signals the start of the major data transmission interval to other nodes on network bus 190, it is preferable that the first specific combination of symbols used in TDM periodic beacon 202 is highly distinguishable when encoded using Differential Manchester Encoding (DME) as used in 10Base-T1S PCS, even in the presence of noise and bandwidth limitations. Figure 3a In the example shown, the symbol combination “NNNN” is used as the first specific symbol combination because it is highly distinguishable from other symbol combinations used in the protocol described herein. However, those skilled in the art will understand that other symbol combinations not used otherwise in the protocol described herein or used in different contexts of the protocol described herein may also be suitable.

[0089] Each major data microframe 310, 320, and 330 includes a header 312, followed by a five-symbol scrambler synchronization sequence 314. Following the scrambler synchronization sequence 314 are data samples 316 transmitted by the nodes, followed by a frame end delimiter 318. The data samples 316 in each major data microframe 310, 320, and 330 are scrambled, and the receiving nodes (i.e., nodes 110–180 that receive the major data microframes) can descramble the data samples 316 using the scrambler synchronization sequence 314.

[0090] In this example, header 312 includes a second specific combination of four symbols from the 5-bit symbolic alphabet used in the Physical Coding Sublayer (PCS) of 10Base-T1S Ethernet (as defined by the IEEE Std 802.3cg-2019 standard). Similar to TDM periodic beacons 202, it is preferable that, in the presence of noise and bandwidth limitations, when using DME encoding, the second specific combination of symbols in header 312 is highly distinguishable to differentiate the primary data microframe from ordinary Ethernet frames. Figure 3a In the example shown, the symbol combination “JJHH” is used as a second specific symbol combination in the microframe header 312 because it is highly distinguishable from other symbol combinations used in the protocol described herein. However, those skilled in the art will understand that other symbol combinations not used otherwise in the protocol described herein or used in different contexts of the protocol described herein may also be suitable.

[0091] The frame end delimiter 318 in this example includes two symbols (T and R in this case) that signal the end of the main data microframe to other nodes on the network bus 190 (i.e., nodes other than the transmission node).

[0092] In some examples, the data samples 316 in the main data microframes 310, 320, and 330 all have the same sampling rate, meaning the source of the derived data samples is sampled at a single sampling rate, making the main data microframes 310, 320, and 330 constitute single-rate main data microframes. For example, the data samples 316 in the main data microframes 310, 320, and 330 could all be audio stream samples sampled at an 8kHz sampling rate.

[0093] In other examples, the primary data microframes 310, 320, and 330 may be multi-rate primary data frames, where one or more sources sample at two or more different sampling rates. For example, the data samples of primary data microframes 310, 320, and 330 may include one or more samples of a first audio stream sampled at a first sampling rate of 8 kHz, and one or more samples of a first audio data stream sampled at a second sampling rate of 48 kHz. Alternatively, the samples at the second sampling rate may be samples of a second audio stream sampled at a different sampling rate than the first audio data stream; for example, the first audio data stream has a sampling rate of 8 kHz, while the second audio stream has a sampling rate of 48 kHz. In these examples, the primary data microframes are transmitted at a TDM period rate corresponding to the lower of the two sampling rates, such as 8 kHz.

[0094] Figure 3b Such multi-rate primary data microframes are shown. For example... Figure 3bThe multi-rate microframes, generally shown in reference 350, include those mentioned above. Figure 3a The description includes a header 312 and a five-symbol scrambler synchronization sequence 314. Following the scrambler synchronization sequence 314 is multi-rate TDM data, which in this example includes a first audio sample 352 sampled at 8 kHz and second through seventh audio samples 354–364 sampled at 48 kHz. In this example, the main data microframe 350 will be transmitted at a TDM cycle rate of 8 kHz, as this corresponds to the lower of the two sample rates for samples 352–364.

[0095] Parent nodes 110 and child nodes 130–180 in network 100 can implement minimum microframe gaps or delays (i.e., time intervals between adjacent primary data microframes and between the end of TDM periodic beacon 202 and the first primary data microframe) to prevent overlap of primary data microframe transmissions from different nodes due to propagation delays (e.g., in network bus 190), and / or to prevent signal decoding errors between primary data microframes. For example, a minimum gap or delay of 0.5 microseconds can be implemented between TDM periodic beacon 202 and the first primary data microframe, and between adjacent primary data microframes.

[0096] Although data samples 316 in each of the main data microframes 310, 320, and 330 are scrambled, the transmission mode of the TDM periodic beacon 202 and the main data microframes 310, 320, and 330 repeats at the TDM periodic beacon rate, which is... Figure 3a The example shown is 8 kHz (but this rate can vary depending on the application using a beacon-based transmission scheme, for example, between 4 kHz and 48 kHz), and the main data microframe transmission pattern (including header 312, scrambler synchronization sequence 314, data sample 316, and frame end delimiter) repeats periodically multiple times within the TDM cycle. This can result in strong periodicity at frequencies several times higher than the TDM cycle beacon rate, generating strong tonal harmonics at low frequencies of several hundred kHz. Such harmonics can cause problems in applications using AM (amplitude modulation) bands (e.g., in the 535 kHz – 1605 kHz frequency range). Examples of such applications include automotive applications in vehicles with AM radio receivers, or automotive applications using AM frequencies for key fobs used to remotely control vehicle locking, unlocking, and / or other functions.

[0097] To alleviate this situation, some methods can be used to break the tonal content (especially in the AM band).

[0098] In one approach, the transmission timing of the TDM periodic beacon 202 is randomly (or pseudo-randomly) delayed from its nominal location by a number of symbol periods, for example, up to 15 symbol periods, according to a suitable random (or pseudo-random) distribution function (such as a random probability density function (RPDF) with variable amplitude or a triangular probability density function (TPDF)). This has the effect of breaking the periodicity of the transmission of the TDM periodic beacon 202, thereby reducing the tonal content generated by the periodic transmission of the TDM periodic beacon 202.

[0099] A randomized value indicating the number of symbol periods of delay for the TDM periodic beacon is appended to the symbol indication of the TDM periodic beacon (or otherwise associated with it). The receiving node uses the randomized value to compensate for timing issues in the generation of the phase-locked loop (PLL) reference clock. For example, the randomized value can be loaded into a 4-bit counter that increments at the symbol rate, and when the counter rolls back to zero, the PLL reference clock generation is asserted. In this way, even if the transmission timing of the TDM periodic beacon is randomized, the frequency and phase of the generated PLL reference clock are consistent.

[0100] In another approach, each node 110–180 can randomize (or pseudo-randomize) the transmission delay of the main data microframe by a number of symbol periods with a variable amplitude, based on a suitable random (or pseudo-random) distribution function (such as a random probability density function (RPDF) or a triangular probability density function (TPDF) with variable amplitude). This has the effect of breaking the periodicity of the transmission of the main data microframe, thereby reducing the tonal content caused by the periodic transmission of the main data microframe. This approach maintains a minimum inter-microframe gap or delay, ensuring that the random (or pseudo-random) delay is outside the inter-microframe gap or delay.

[0101] The channel configuration of network 100 is static but configurable. That is, the configuration of network 100 cannot be changed during network operation, but if all nodes 110-180 are disabled, reconfigured and then re-enabled, the configuration of network 100 can be changed to accommodate different numbers of nodes (e.g., if one or more new nodes are added to network 100) or different channel configurations of existing nodes.

[0102] Network configuration information can be provided for each node 110–180 in network 100, which indicates the number of transmission channels for each node and the predefined primary data transmission order.

[0103] Each node 110–180 operates to use network configuration information to determine the correct point within the main data transmission interval 210 to transmit its main data microframe. For example, each node 110–180 may operate to determine a byte or time offset from the TDM periodic beacon based on the node’s position in a predefined main data transmission sequence and the number of transmission channels of each preceding node in the predefined main data transmission sequence. This offset represents the point within the main data transmission interval 210 where the node should transmit its main data microframe to the network bus 190.

[0104] In other examples, each node 110–180 can count the number of delimited transmissions on network bus 190 since the transmission of TDM periodic beacon 202 to determine the correct point in time to transmit its primary data microframe within primary data transmission interval 210. For example, each node can count the number of frame end delimiters 318 that have been transmitted to network bus 190 since TDM periodic beacon 202 and compare the result with its own position in a predefined primary data transmission sequence to determine the point in primary data transmission interval 210 where the node should transmit its primary data microframe to network bus 190.

[0105] Refer again Figure 2 After all nodes 110–180 have transmitted their primary data microframes to network bus 190, any available bus time before the next TDM cycle beacon 202 is transmitted to network bus 190 (i.e., the time during which no data is transmitted to network bus 190) can be used to provide auxiliary data transmission interval 230, during which nodes 110–180 can transmit auxiliary data such as Ethernet data to network bus 190 in a predefined auxiliary data transmission order.

[0106] To this end, the parent node 110 further operates to broadcast or transmit a second beacon signal (also known as a data periodic beacon) instead of the TDM periodic beacon 202 to the network bus 190 to indicate the start of an auxiliary data frame, wherein each node 110–180 has the opportunity to transmit an auxiliary data frame to the network bus 190.

[0107] Figure 4 yes Figure 2 A schematic diagram of a beacon-based transmission scheme is shown, illustrating the transmission of auxiliary data (e.g., Ethernet data) and primary data (e.g., audio data).

[0108] exist Figure 4 In the example shown, the second beacon signal 412 (also known as the data periodic beacon) is transmitted from the parent node 110 to the network bus 190, instead of the TDM periodic beacon 202. Figure 4The sequence of first to fourth consecutive TDM beacon periods 410, 420, 430, and 440 is shown, wherein a data periodic beacon 412 is transmitted at the beginning of the first TDM beacon period 410 and the beginning of the fourth TDM beacon period 440, and a TDM periodic beacon 202 is transmitted at the beginning of each of the second TDM beacon period 420 and the third TDM beacon period 430.

[0109] Data cycle beacon 412 includes a third specific symbol combination from the 5-bit symbol alphabet used in the Physical Coding Sublayer (PCS) of 10Base-T1S Ethernet (as defined by the IEEE Std 802.3cg-2019 standard). This third specific symbol combination differs from the first specific signal combination used in TDM cycle beacon 202 to allow the receiving node to distinguish data cycle beacon 412 from TDM cycle beacon 202.

[0110] The data periodic beacon 412 has two functions.

[0111] Its primary function is the same as that of the TDM periodic beacon 202, to indicate or define the start of the primary data transmission interval 210 by signaling, so as to transmit the primary data to the network bus 190.

[0112] The secondary function of the data cycle beacon 412 is to signal, define, or initiate an auxiliary data frame cycle, where each node 110–180 has the opportunity (also known as a frame transmission opportunity) to transmit an auxiliary data frame to the network bus 190. The auxiliary data frames transmitted from nodes 110–180 to the network bus 190 during a frame transmission opportunity can be Ethernet data frames. Frame transmission opportunities are provided to nodes according to a predefined auxiliary data transmission order.

[0113] For example, data periodic beacon 412 may include the symbol combination NNNNHRJN. It should be noted that in this example, the first four symbols of the data periodic beacon are the same as those referenced above. Figure 3a The symbols used for the TDM periodic beacon 202 are identical. Using the same combination of symbols at the beginning of both the TDM periodic beacon 202 and the data periodic beacon 412 helps ensure that the child nodes 130–180 of network 100 recognize the data periodic beacon 412 as indicating the start of a TDM beacon period and the start of an auxiliary data frame period.

[0114] The operation of the auxiliary data frame cycle is similar to the physical layer collision avoidance (PLCA) scheme used in 10Base-T1S Ethernet, ensuring that each node 110-180 has the opportunity to transmit an auxiliary data frame after all nodes 110-180 (with primary data to transmit) have transmitted their primary data microframes to the network bus 190 within each data cycle beacon period.

[0115] Therefore, in Figure 4 In the example shown, during the first TDM beacon period 410, a data cycle beacon 412 is transmitted to signal the start of the main data transmission interval 210 and initiate the auxiliary data frame cycle. Immediately after the data cycle beacon 412 has been transmitted, nodes 110-180 transmit their main data microframes 414 of the first TDM beacon period 410 to the network bus 190 during the main data transmission interval 210, according to a predefined main data transmission order, as referenced above. Figure 2 As stated above. Therefore, it should be understood that... Figure 4 Box 414 represents all major data microframes transmitted by nodes 110–180 within the major data transmission interval 210 of the TDM beacon period 410.

[0116] Once all the primary data microframes 414 of nodes 110–180 that have primary data to transmit have been transmitted within the primary data transmission interval 210 of the first TDM beacon period 410, nodes 110–180 can transmit one or more auxiliary data frames (e.g., Ethernet frames) in a predefined auxiliary data transmission order within the auxiliary data transmission interval 230 between the end of the primary data transmission interval 210 and the transmission of the TDM periodic beacon 202 of the second TDM beacon period 420.

[0117] exist Figure 4 In the example shown, three nodes (e.g., parent node 110 (node ​​0), amplifier node 130 (node ​​1), and first microphone node 150A (node ​​2)) each have auxiliary data frames to transmit. Therefore, during the auxiliary data frame period following the data transmission period beacon 412, the node with auxiliary data frames to transmit will transmit auxiliary data frames 416, 426, and 428.

[0118] During the auxiliary data transmission interval 230 of the first TDM beacon period 410, the first of the nodes with auxiliary data to transmit (e.g., parent node 110) transmits its auxiliary data frame 416 to the network bus 190. After the auxiliary data frame 416 has been transmitted, the network bus 190 remains inactive until the start of the second TDM beacon period 420.

[0119] At the beginning of the second TDM beacon period 420, the parent node 110 transmits the TDM periodic beacon 202. Immediately after the TDM periodic beacon 202 has been transmitted, nodes 110-180 transmit the main data microframes 424 of the second TDM beacon period 420 to the network bus 190 during the main data transmission interval 210, according to a predefined main data transmission order, as referenced above. Figure 2 As stated above.

[0120] Once all the primary data microframes 424 of nodes 110–180 have been transmitted within the primary data transmission interval 210 of the second TDM beacon period 420, the second and third nodes (e.g., amplifier node 130 and first microphone node 150A) to transmit auxiliary data transmit auxiliary data frames (e.g., Ethernet frames) 426, 428 within the auxiliary data transmission interval 230 between the end of the primary data transmission interval 210 and the transmission of the TDM periodic beacon 202 of the third TDM beacon period 430.

[0121] After auxiliary data frames 426 and 428 have been transmitted, network bus 190 remains inactive until the third TDM beacon period 430 begins.

[0122] At the beginning of the third TDM beacon period 430, the parent node 110 transmits the TDM periodic beacon 202. Immediately after the TDM periodic beacon 202 has been transmitted, nodes 110-180 transmit the main data microframe 434 of the third TDM beacon period 420 to the network bus 190 during the main data transmission interval 210, according to a predefined main data transmission order, as referenced above. Figure 2 As stated above.

[0123] Furthermore, once all primary data microframes 434 of nodes 110–180 have been transmitted within the primary data transmission interval 210 of the third TDM beacon period 430, nodes 110–180 have the opportunity to transmit auxiliary data frames within the auxiliary data transmission interval 230 after the end of the primary transmission interval 210 and the beginning of the fourth TDM beacon period 440.

[0124] In this example, nodes with auxiliary data to transmit have transmitted their auxiliary data frames during the auxiliary data transmission interval 230 of the first TDM beacon interval 410 and the second TDM beacon interval 420, while nodes without auxiliary data to transmit have the opportunity to transmit auxiliary data during the auxiliary data transmission intervals of the second TDM beacon interval 420 and the third TDM beacon interval 430.

[0125] Since all nodes of network 100 have the opportunity to transmit auxiliary data frames within the auxiliary data frame period indicated by the data period beacon 412 transmitted at the beginning of the first TDM beacon interval 410, instead of transmitting the TDM period beacon 202 at the beginning of the fourth TDM beacon interval 440, the parent node 110 transmits another data period beacon 412a to indicate both the beginning of the fourth TDM beacon interval 440 and the beginning of the new auxiliary data frame period.

[0126] Immediately after the transmission of beacon 412a in this new data cycle, nodes 110-180 transmit the main data microframe 444 of the fourth TDM beacon period 440 to network bus 190 during the main data transmission interval 210, according to a predefined main data transmission order, as referenced above. Figure 2 As stated above.

[0127] Furthermore, once all primary data microframes 444 of nodes 110–180 have been transmitted within the primary data transmission interval 210 of the fourth TDM beacon period 440, nodes 110–180 have the opportunity to transmit data at the end of the primary transmission interval 210 and during the fifth TDM beacon period (…). Figure 4 Auxiliary data frames are transmitted within the auxiliary data transmission interval 230 between the start of the auxiliary data transmission (not shown in the figure).

[0128] In this example, the first node (e.g., parent node 110) in the predetermined auxiliary data transmission sequence to transmit auxiliary data frames transmits auxiliary data frame 446 within the auxiliary data transmission interval 230 of the fourth TDM beacon period 440. Other nodes in network 100 each have an opportunity to transmit auxiliary data frames. After all nodes have transmitted their auxiliary data frames (if they have auxiliary data to transmit) or have been allowed to miss their opportunity to transmit auxiliary data frames without transmitting them (if they have no auxiliary data to transmit), parent node 110 will transmit data period beacon 412 again at the beginning of the next TDM beacon period, replacing TDM period beacon 202.

[0129] Parent node 110 and child nodes 130-180 can be configured to implement random or pseudo-random delays in the transmission timing of their respective auxiliary data frames, similar to the random or pseudo-random delays introduced by parent node 110 for TDM periodic beacons 202, and / or the random or pseudo-random delays introduced by nodes 110-180 for primary data microframes, in order to reduce tone content that may arise due to the periodic transmission of auxiliary data frames.

[0130] In some cases, an auxiliary data frame transmitted by one of nodes 110–180 may exceed the available idle time of network bus 190 after the transmission of all major data microframes from nodes 110–180 within a TDM beacon period, making it impossible to transmit the complete auxiliary data frame to network bus 190 before the next TDM cycle beacon 202 is transmitted. In this case, the data frame may be split into two or more TDM beacon periods.

[0131] Figure 5a yes Figure 2A schematic diagram of a beacon-based transmission scheme is shown, illustrating the transmission of auxiliary data (e.g., Ethernet data) and primary data (e.g., audio data), wherein auxiliary data frames are segmented within multiple TDM beacon periods.

[0132] exist Figure 5a In the example shown, instead of the TDM periodic beacon 202, the parent node 110 transmits the data periodic beacon 412 to the network bus 190 to signal the start of the auxiliary data frame period. Figure 5a The sequence of first to fourth consecutive TDM beacon periods 510, 520, 530, 540 is shown, wherein a data periodic beacon 412 is transmitted at the beginning of the first TDM beacon period 510, and a TDM periodic beacon 202 is transmitted at the beginning of each of the second to fourth TDM beacon periods 520–540.

[0133] Therefore, in Figure 5a In the example shown, during the first TDM beacon period 510, a data cycle beacon 412 is transmitted to signal the start of the main data transmission interval 210 and to signal or initiate an auxiliary data frame period. Immediately after the data cycle beacon 412 has been transmitted, nodes 110-180 transmit their main data microframes 512 of the first TDM beacon period to the network bus 190 during the main data transmission interval 210 according to a predefined main data transmission order, as referenced above. Figure 2 As stated above. Therefore, it should be understood that... Figure 5a Box 512 represents the main data microframes transmitted by all nodes 110–180 within the main data transmission interval 210 of the first TDM beacon period 510.

[0134] Once the primary data microframes 512 of all nodes 110–180 have been transmitted within the primary transmission interval 210 of the first TDM beacon period 510, each node 110–180 has the opportunity to transmit an auxiliary data frame. The auxiliary data frames (e.g., Ethernet frames) are transmitted by nodes 110–180 within the auxiliary data transmission interval 230 according to a predefined auxiliary data transmission order.

[0135] In this example, parent node 110 (node ​​0) and second microphone node 150B (node ​​3) each have auxiliary data frames to transmit, while amplifier node 130 (node ​​1) and first microphone node 150A (node ​​2) do not have auxiliary data frames to transmit.

[0136] During the auxiliary data transmission interval 230 of the first TDM beacon period 510, the parent node 110 transmits its data frame 514. In this example, the amplifier node 130 and the first microphone node 150A each transmit corresponding "yield" signals 516 and 518, indicating that they have no data frames to transmit during the auxiliary data transmission interval 230 of the first TDM beacon period 510. In this example, data frame 514 and yield signals 516 and 518 occupy all available idle time of the network bus 190 within the first TDM beacon period 510.

[0137] At the beginning of the second TDM beacon period 520, the parent node 110 transmits the TDM periodic beacon 202. Immediately after the TDM periodic beacon 202 has been transmitted, nodes 110-180 transmit the main data microframes 522 of the second TDM beacon period 520 to the network bus 190 during the main data transmission interval 210, according to a predefined main data transmission order, as referenced above. Figure 2 As stated above.

[0138] Once all the primary data microframes 522 of nodes 110-180 have been transmitted within the primary data transmission interval 210 of the second TDM beacon period 520, nodes 110-180 can continue to transmit auxiliary data frames in the auxiliary data transmission interval 230 of the second TDM beacon period 520 according to the predefined auxiliary data transmission order.

[0139] Therefore, the second microphone node 150B (node ​​3) begins transmitting its auxiliary data frame 524 within the auxiliary data transmission interval 230 of the second TDM beacon period 520. However, in this example, the auxiliary data frame of the second microphone node 150B has a longer available idle time on the network bus 190 after transmitting the main data microframes 522 of all nodes 110–190 within the main data transmission interval 210 of the second TDM beacon period 520, and therefore cannot be transmitted completely within the auxiliary data transmission interval 230 of the second TDM beacon period 520. To allow the complete transmission of the auxiliary data frame 524, the auxiliary data frame 524 is divided into multiple (three in this example) parts 524a, 524b, and 524c. Only the first part 524a, with a length equal to (or shorter than) the available idle time of the network bus 190, is transmitted within the auxiliary data transmission interval 230 of the second TDM beacon period 520. The remaining portions 524b and 524c are transmitted in the subsequent third TDM beacon period 530 and fourth TDM beacon period 540.

[0140] At the beginning of the third TDM beacon period 530, a new TDM periodic beacon 202 is transmitted by parent node 110. Immediately after this new TDM periodic beacon 202 has been transmitted, nodes 110-180 transmit the main data microframe 532 of the third TDM beacon period 530 to network bus 190 during the main data transmission interval 210, according to a predefined main data transmission order, as referenced above. Figure 2 As stated above.

[0141] Once all the primary data microframes 532 of nodes 110-180 have been transmitted within the primary data transmission interval 210 of the third TDM beacon period 530, nodes 110-180 can continue to transmit auxiliary data frames in the auxiliary data transmission interval 230 of the third TDM beacon period 530 according to the predefined auxiliary data transmission order.

[0142] In this example, the second portion 524b of the auxiliary data frame 524 of the second microphone node 150B is transmitted during the auxiliary data transmission interval 230 of the third TDM beacon period 530. The length of the second portion 524b is equal to (or shorter than) the available idle time of the network bus 190 after the transmission of the main data microframe 532 during the main data transmission interval 210 of the third TDM beacon period 530.

[0143] In this example, the auxiliary data frame 524 of the second microphone node 150B has a longer combined available idle time on the network bus 190 after the transmission of the main data microframes 522 and 532 in the second TDM beacon period 520 and the third TDM beacon period 530. Therefore, the third part 524c of the auxiliary data frame 524 is transmitted within the auxiliary data transmission interval 230 of the fourth TDM beacon period 540 after the transmission of another TDM periodic beacon 202 and the main data microframe 542 in the fourth TDM beacon period 540.

[0144] The transmission nodes (nodes 110-180, which will transmit data frames during the current audio sampling period) operate to determine whether to transmit auxiliary data frames, and whether the auxiliary data frames should be segmented over two or more audio sampling periods as described above.

[0145] If the length of the auxiliary data frame to be transmitted is perfectly suited to the auxiliary data transmission interval 230 of the current TDM beacon period between the end of the main data transmission interval 210 and the transmission of the TDM periodic beacon 202 or data periodic beacon 412 of the next audio sampling period, then the auxiliary data frame is transmitted by transmission nodes 110–180 in the same manner as a 10Base-T1S / IEEE 802.3cg compatible Ethernet frame. Figure 5aIn the example shown, auxiliary data frame 514 transmitted by the parent node (node ​​0) is transmitted in this manner.

[0146] Figure 5b The structure of the auxiliary data frame transmitted in this manner is shown. For example... Figure 5b As shown, the auxiliary data frame 550 includes a preamble 552, which in this example includes the four-symbol combination JJHH, followed by a five-symbol scrambler synchronization sequence 554, followed by a preamble remainder 556 with a value of 55555D, followed by the auxiliary data content 558 of the auxiliary data frame 550 (whose length can be between 64 and 1536 octets), followed by a frame end delimiter 560 (which in this example includes the two-symbol combination TR).

[0147] In some examples, if the transmission node 110-180 determines that the next TDM cycle beacon 202 or data cycle beacon 412 is expected to be transmitted within a predefined time period (e.g., 15 symbol periods plus a predefined timing margin), it will not begin transmitting its auxiliary data frame within the current TDM beacon period because there may not be enough remaining time to transmit at least one octet of the data frame within the current TDM beacon period.

[0148] If transmission nodes 110–180 have begun transmitting auxiliary data frames and determine that the next TDM cycle beacon 202 is expected to be transmitted within a predefined time period (e.g., a 6-symbol period), it pauses the transmission of auxiliary data frames at the octet boundary and transmits a "pause" symbol combination (e.g., JHNR). After the main data transmission interval 210 of the next TDM beacon period ends, the transmission nodes resume the transmission of auxiliary data frames by transmitting a "resumption" symbol combination (e.g., JHNR), followed by a synchronization sequence (which may include five symbols) and the remaining data of the auxiliary data frames. Figure 5a In the example shown, the auxiliary data frame 524 transmitted by the second microphone node 150B is transmitted in this manner, wherein the "pause" symbol combination is transmitted in the auxiliary data transmission interval 220 of the second TDM beacon period 520 and the third TDM beacon period 530, and the "resume" symbol combination is transmitted at the beginning of the auxiliary data transmission interval 220 of the third TDM beacon period 530 and the fourth TDM beacon period 540.

[0149] Figure 5c The transmission of a portion of auxiliary data frames using a combination of pause and resume symbols is shown.

[0150] During the first TDM beacon period, a first auxiliary data frame 570 is transmitted. The first auxiliary data frame includes a preamble 572, which in this example includes the four-symbol combination JJHH, followed by a five-symbol scrambling synchronization sequence 574, followed by a preamble remainder 575, followed by the content of the first auxiliary data frame 576 (whose length can be between 1 and 1535 octets), followed by a "pause" symbol combination (in this example, it includes the four-symbol combination JHNR).

[0151] During the second TDM beacon period, the second part of the auxiliary data frame 580 is transmitted. The second part of the auxiliary data frame 580 includes a "recovery" symbol combination 582, which in this example includes a four-symbol combination JHNR, followed by a five-symbol scrambler synchronization sequence 584, followed by the content of the second part of the auxiliary data frame 586 (whose length may be between 1 and 1535 octets), followed by a frame end delimiter 588 (in this example, it includes a two-symbol combination TR).

[0152] References above Figure 5a In the example described, multiple transmission opportunity windows are provided, where each node 110–180 can transmit auxiliary data frames or yield signals sequentially (in accordance with a predefined auxiliary data transmission order) if it has no data frames to transmit.

[0153] In an alternative approach, each node 110–180 includes a transmission opportunity counter that operates to count transmission opportunities since the transmission of data periodic beacon 412 and uses the value of its transmission opportunity counter to determine when to transmit auxiliary data frames in the auxiliary data transmission interval 230.

[0154] When the parent node 110 transmits the periodic beacon 412, the transmission opportunity counter for each node 110-180 is initialized (e.g., reset to a predefined value, such as zero), and this counter increments whenever a node 110-180 transmits its auxiliary data frame to the network bus 190. Nodes 110-180 can determine a transmission opportunity window within the auxiliary data transmission interval 230 based on a comparison between the value of their position in the predefined auxiliary data transmission sequence and the value of the transmission opportunity counter, so that they can transmit their auxiliary data frame within that window. When the value of the transmission opportunity counter equals the position of node 110-180 in the predefined auxiliary data transmission sequence, that node should transmit its auxiliary data frame within the current transmission opportunity window.

[0155] In this alternative method, if a node has no auxiliary data frames to transmit within the transmission opportunity window, it instead transmits a yield signal, and the node does not transmit any data within the relevant transmission opportunity window. If the transmission opportunity window expires without a corresponding node 110–180 initiating the transmission of an auxiliary data frame (as may be indicated, for example, by transmitting a commit or synchronization symbol of a kind familiar to those skilled in the art by the relevant node 110–180), then the parent node 120 transmits a transmission opportunity increment signal to the network bus 190, which may be, for example, a predefined combination of symbols. In response to the transmission opportunity increment signal, each of the child nodes 130–180 increments its own transmission opportunity counter, such that, taking into account the expiration of the transmission opportunity window, subsequent nodes in the predefined auxiliary data transmission sequence can each transmit their auxiliary data frames within the correct transmission opportunity window.

[0156] Figure 6 This is a schematic diagram illustrating an example of this alternative method.

[0157] exist Figure 6 In the example shown, parent node 110, second microphone node 150B, accelerometer node 170, and bridging node 180 each have auxiliary data frames to transmit during the auxiliary data period, but amplifier node 130 and first microphone node 150A each have no auxiliary data frames to transmit during the auxiliary data period. For simplicity, Figure 6 It is assumed that the lengths of the auxiliary data frames of parent node 110, second microphone node 150B, accelerometer node 170, and bridging node 180 are all perfectly suited to the auxiliary data transmission interval 230 of the current TDM beacon period between the end of the main data transmission interval 210 and the transmission of the TDM periodic beacon 202 of the next TDM beacon period. However, it should be understood that longer auxiliary data frames may be used as described above. Figure 5a The method described involves segmentation between two or more TDM beacon time periods.

[0158] exist Figure 6 In the example shown, parent node 110 occupies position 0 in the predefined auxiliary data transmission sequence. Amplifier node 130, first microphone node 150A, second microphone node 150B, and accelerometer node 170 occupy positions 1, 2, 3, and 4 in the predefined auxiliary data transmission sequence, respectively. The transmission opportunity counter for each node 110–180 is set to zero at the transmission data cycle beacon 412, which signals the start of both the primary data transmission interval 210 and the auxiliary data cycle.

[0159] Therefore, when the transmission opportunity counters of all nodes 110-180 are 0 immediately after the transmission data cycle beacon 412, the value of each transmission opportunity counter is equal to the value of the parent node 110's position in the predefined auxiliary data transmission order, and the parent node transmits its auxiliary data frame 614 within the current transmission opportunity window 652.

[0160] The transmission of data frame 614 is detected by nodes 110-180. In response, each node increments its corresponding transmission opportunity counter so that its value is now 1.

[0161] The transmission opportunity counter value corresponds to the position of amplifier node 130 in the predefined auxiliary data transmission sequence. However, amplifier node 130 has no auxiliary data frames to transmit. Therefore, a yield signal (such as...) is transmitted instead. Figure 5a (As in the example), amplifier node 130 does not transmit any signal during the current transmission opportunity window 654.

[0162] Parent node 110 detects that the transmission opportunity window 654 has passed without transmitting an auxiliary data frame, and therefore transmits a transmission opportunity increment signal 655 to network bus 190. In response, each of nodes 130-180 increments its transmission opportunity counter, such that the value of each transmission opportunity counter is 2.

[0163] The transmission opportunity counter value corresponds to the position of amplifier node 150A in the predefined auxiliary data transmission sequence. As mentioned above, the first microphone node 150A has no auxiliary data frames to transmit. Therefore, a yield signal (such as...) is transmitted instead. Figure 5a (As in the example), the first microphone node 150A does not transmit any signal during the current transmission opportunity window 656.

[0164] Furthermore, parent node 110 detects that the transmission opportunity window 656 has passed without transmitting an auxiliary data frame, and therefore transmits a transmission opportunity increment signal 657 to network bus 190. In this example, since the transmission opportunity window 656 passed shortly before the transmission of the next TDM cycle beacon 202, the transmission of the transmission opportunity increment signal 657 is delayed until the start of the next auxiliary data interval after the main data microframe 622 has been transmitted by the node during the main data interval 210 of the second TDM beacon period 620. In response to the transmission opportunity increment signal 657, each of nodes 130–180 again increments its transmission opportunity counter, such that the value of each transmission opportunity counter is now 3.

[0165] The transmission opportunity counter value corresponds to the position of the second microphone node 150B in the predefined auxiliary data transmission sequence, so the second microphone node 150B transmits its auxiliary data frame 624 during the current transmission opportunity window 658.

[0166] The transmission of auxiliary data frame 624 was detected by nodes 110-180. In response, each node incremented its corresponding transmission opportunity counter so that their values ​​were now 4.

[0167] The transmission opportunity counter value corresponds to the position of the accelerometer node 170 in the predefined auxiliary data transmission sequence, so the accelerometer node 170 transmits its auxiliary data frame 626 during the current transmission opportunity window 660.

[0168] Furthermore, the transmission of auxiliary data frame 626 was detected by nodes 110-180, and in response, each node incremented its corresponding transmission opportunity counter again, so that their values ​​are now 5.

[0169] The transmission opportunity counter value corresponds to the position of the bridging node 180 in the predefined auxiliary data transmission sequence, so the bridging node 180 transmits its auxiliary data frame 628 during the current transmission opportunity window 662.

[0170] This method forces child nodes 130-180 to increment their transmission opportunity counters, ensuring that the transmission opportunity counters of all child nodes 130-180 are synchronized, consistent with the above. Figure 5a Compared to the described yield signal, this in turn improves the robustness and resilience of network 100.

[0171] If in Figure 5a If a node fails in the yield signaling method, the failed node will not transmit any signals to the network bus within the relevant transmission opportunity window. The absence of any signals can cause subsequent nodes in the predefined auxiliary transmission sequence to fail to transmit their corresponding auxiliary data frames, resulting in interruption or failure of data frame transmission in network 100.

[0172] In contrast, in the above reference Figure 6 In the described transmission opportunity increment signal method, the parent node 110, which increments the transmission opportunity counter of all nodes, detects that a node has no signal in a given transmission opportunity window (whether due to node failure or because the node has no auxiliary data frame to transmit), so that subsequent nodes in the predefined auxiliary transmission order can continue to transmit their auxiliary data frames in sequence.

[0173] like Figure 6As shown, if the transmission opportunity window (e.g., transmission opportunity window 656) has passed within a predefined period (e.g., 15 symbol times plus a predefined timing margin) before the scheduled transmission of the next TDM cycle beacon 202, the parent node 120 will not immediately transmit the transmission opportunity increment signal. Instead, it will delay the transmission of the transmission opportunity increment signal until after the end of the next microframe cycle, i.e., until the end of the primary data transmission interval 210 indicated by the signal from the next TDM cycle beacon 202. This ensures that auxiliary data frames (e.g., data frame 624) are transmitted to the network bus 190 only after the microframe (e.g., microframe 622) associated with the next TDM cycle beacon 202, thus reducing the risk of collisions between primary and auxiliary data.

[0174] If the transmission opportunity counter of parent node 110 reaches a predefined maximum value (equal to the total number of nodes coupled to network bus 190), then parent node 120 will not transmit a transmission opportunity increment signal, but will instead transmit a new data cycle beacon 412 of the type described above to replace the next TDM cycle beacon 202, thus starting a new auxiliary data cycle and re-initializing the transmission opportunity counters of all nodes 110-180.

[0175] As those skilled in the art will understand, incrementing the transmission opportunity counters in parent node 110 and child nodes 130-180 is a method for maintaining the correct timing of auxiliary data frames transmitted by the nodes, ensuring that each node transmits its auxiliary data at the correct point in the auxiliary data cycle, and other methods for maintaining the correct timing of auxiliary data frames may also be employed.

[0176] For example, instead of initializing the transmission opportunity counter to zero and incrementing it in response to a transmission opportunity increment signal transmitted by parent node 110, the node's transmission opportunity counter can be initialized to a value equal to the number of nodes coupled to network bus 190, and can be decremented in response to a transmission opportunity decrement signal transmitted by parent node 110 when a transmission opportunity window is detected to have passed without the node transmitting an auxiliary data frame.

[0177] As another example, parent node 110 may transmit a symbol containing an identifier of the next node that is permitted to transmit auxiliary data frames to network bus 190.

[0178] In some examples, TDM periodic beacons and data periodic beacons can be used to transmit clock sampling rate information to nodes 130–180.

[0179] Figure 7 This is a schematic diagram showing the recovery of the audio sampling rate clock from the TDM periodic beacon.

[0180] As described above, the TDM periodic beacon 202 is transmitted periodically by the parent node 110, for example, once per audio sampling period. Once each node coupled to the network bus 190 has the opportunity to transmit auxiliary data frames during the auxiliary data period, the TDM periodic beacon 202 can be replaced by the data periodic beacon 412, as referenced above. Figures 4 to 6 As discussed. Therefore, for an audio sampling rate of 8 kHz, parent node 110 transmits a TDM periodic beacon 202 or a data periodic beacon 412 every 125 µs.

[0181] Parent node 110 can be configured to begin transmitting each TDM cycle beacon 202 and data cycle beacon 412 synchronously with an audio sampling clock event (e.g., an audio cycle clock pulse), such that the start of each TDM cycle beacon 202 and data cycle beacon 412 is time-aligned with the audio sampling clock event. Child nodes 130–180 can use these periodic beacon signals to recover the audio sampling clock, which can then be used as clock signals for the analog-to-digital converters (ADCs), digital-to-analog converters (DACs), and other components or subsystems of child nodes 130–180 that require an audio sampling clock.

[0182] When a complete TDM cycle beacon 202 or data cycle beacon 412 is detected on network bus 190, each child node 130–180 generates a TDM cycle beacon detection pulse, which may be a single pulse from logic 0 to logic 1. One TDM cycle beacon detection pulse is generated for each detected TDM cycle beacon 202 or data cycle beacon 412. A series of such pulses forms the TDM cycle beacon detection signal, which serves as a frequency and phase reference signal supplied to the phase-locked loop (PLL) of the clock recovery system of the child device (e.g., PLL 156 of the first microphone node 150A). The PLL outputs a clock signal that is frequency and phase locked to the TDM cycle beacon detection signal. The clock recovery system can apply phase adjustment to compensate for the duration of the TDM cycle beacon 202 / data cycle beacon 412.

[0183] Figure 7 The audio sampling clock event sequence of the parent node 110 is shown. TDM periodic beacons 202 are transmitted synchronously by the parent node 110 with each audio sampling clock event, but for clarity, Figure 7 Only one TDM cycle beacon is shown, synchronized with the first audio sampling clock event 712.

[0184] Due to the latency introduced by the parent node's physical layer interface 112, the actual transmission time of the TDM periodic beacon 202 can be offset positively or negatively from the corresponding sampling clock event, allowing the TDM periodic beacon 202 to be transmitted earlier or later than the corresponding sampling clock event. The maximum offset (positive or negative) can be referred to as t. PHY / 2. Figure 7 The average transmission timings of TDM periodic beacons 202a (transmitted with the maximum positive offset, i.e., the earliest transmission timing of the TDM periodic beacon), 202b (transmitted with the maximum negative offset, i.e., the latest transmission timing of the TDM periodic beacon), and 202c are shown.

[0185] During multiple audio sampling clock periods, the transmission timing of the TDM periodic beacon 202 and data periodic beacon 412 performed by the parent node 110 will tend towards Figure 7 The average transmission timing shown is 202c.

[0186] When a child node detects a complete TDM cycle beacon 202 or data cycle beacon 412 on network bus 190, it outputs a TDM cycle beacon detection pulse 722. As described above, a series of such pulses forms a TDM cycle beacon detection signal, which is supplied as a frequency and phase reference signal to the PLL of the child node's clock recovery system.

[0187] The PLL filters out jitter and outputs an output signal 732 with the average phase of the frequency and phase reference signals. The clock recovery system can then apply phase adjustment (such as...). Figure 7 (As indicated by arrow 742 in the image), to generate a phase-adjusted audio sampling clock event 752 at the child node.

[0188] Figure 8 This is a schematic diagram of an isochronous data transceiver system, which can be included in nodes of a multipoint communication network. The system and method disclosed herein can be implemented in nodes of this multipoint communication network, for example in... Figure 1 In network 100, there are parent node 110 and child nodes 130-180.

[0189] The isochronous data transceiver system in this example is an audio transceiver system, which is in Figure 8 The figure is generally shown in 800. However, it should be understood that isochronous data transceiver systems can also be used to transmit and receive other types of isochronous data.

[0190] For example, the audio transceiver system 800 may be included in the physical layer interface 112 and / or protocol logic 118 of the parent node 110, and in the physical layer interfaces 132, 152, 182 and / or protocol logic 134, 154, 184 of the corresponding child nodes 130-180.

[0191] The audio transceiver system 800 in this example includes processing circuitry 810, which (e.g., in firmware executed by processing circuitry 810) implements a link state machine 812 and a framing engine 814. Processing circuitry 810 may include logic circuitry implementing the state machine, or a general-purpose microprocessor or microcontroller executing suitable software or firmware, or any other discrete or integrated circuit configured to implement the link state machine 812 and the framing engine 814.

[0192] The framing engine 814 includes a microframe processor 816 for primary data (e.g., audio data) and a frame processor 818 for auxiliary data (e.g., Ethernet data).

[0193] The audio transceiver system 800 also includes an advanced high-performance bus (AHB) fabric 820, which is coupled to the processing circuitry 810 for bidirectional data communication between the processing circuitry 810 and the AHB fabric 820.

[0194] A set of Media Independent Interface (MII) FIFOs (First-In-First-Out Buffers) 830 are also coupled to the AHB architecture 820 for bidirectional communication of auxiliary (e.g., Ethernet) data frames between the FIFOs 830 and the AHB architecture 820. The FIFO 830 receives data from and transmits data to the MII of the node implementing the audio transceiver system 800 (also called the host node).

[0195] Audio Serial Port (ASP) 840 is implemented in Audio Transceiver System 800 for bidirectional audio data communication between Audio Transceiver System 800 and external devices. Audio data can be, for example, I... 2 S (Inter-integrated circuit sound).

[0196] The audio transceiver system 800 also includes: a 10Base-T1S Physical Coding Sublayer (PCS) 850, coupled to the AHB architecture 820, for bidirectional data communication between the AHB architecture 820 and the PCS 850; and a 10Base-T1S Physical Media Accessory (PMA) 860, coupled to the PCS 850, for bidirectional data transmission between the PCS 850 and the PMA 860. When using the audio transceiver system 800, the PMA 860 is coupled to the network bus 190. The PCS 850 and PMA 860 together provide interface circuitry for interfacing the audio transceiver system 800 with the network bus 190.

[0197] The MII FIFO 830, combined with the host node's MII interface, provides a universal Ethernet interface for transmitting and receiving Ethernet data.

[0198] Auxiliary data frame processor 818 transmits and receives auxiliary data (e.g., Ethernet data) frames to and from network bus 190 via PCS 850 and PMA 860. Similarly, primary data microframe processor 816 transmits and receives data microframes (e.g., containing audio data) to and from network bus 190 via PCS 850 and PMA 860. Framing engine 814 is configured to manage the multiplexing of data frames and microframes, including processing (e.g., generating and transmitting) TDM periodic beacons 202 and data periodic beacons 412, and PLCA frame transmission control.

[0199] The audio transceiver system 800 can be implemented as a standalone integrated circuit (IC), such as the audio transceiver IC 900, etc. Figure 9 It is shown schematically in the diagram.

[0200] Alternatively, the audio transceiver system 800 can be combined with other circuits to form an IC. For example, the audio transceiver system 800 can be combined with amplifier circuit 1002 to form a combined amplifier and audio transceiver IC 1000, such as... Figure 10 It is shown schematically in the diagram.

[0201] Parent node 110 can be implemented in an integrated circuit (e.g., a single integrated circuit or a system-on-a-chip (SoC)), such as Figure 11 The integrated circuit 1100 is generally shown in the figure. The integrated circuit 1100 can be configured to apply a random or pseudo-random delay to the transmission timing of the TDM periodic beacon 202 and to append a randomized value to the TDM periodic beacon 202, as discussed above.

[0202] Each child node 130-180 can be implemented in an integrated circuit (e.g., a single integrated circuit or a system-on-a-chip (SoC)), such as Figure 12 The integrated circuit 1200 is generally shown in the figure. The integrated circuit 1200 can be configured to receive the TDM periodic beacon 202 and additional randomization values ​​from the parent node 110, and to compensate for random or pseudo-random transmission timing in the generation of the phase-locked loop (PLL) reference clock, as discussed above.

[0203] Other features of the system and method of this disclosure are as follows. A system and method for a communication system, preferably a communication bus for an audio system, and preferably for use in an automotive environment.

[0204] A system and method for a communication network, the system being configured to: transmit network beacons on the network at regular intervals to define a beacon period for data transmission; transmit primary data after transmitting the network beacons; and transmit secondary data after the primary data, the secondary data being transmitted for the remainder of the beacon period and before transmitting the next network beacon.

[0205] Preferably, the primary data is low-latency data, while the auxiliary data has more lenient latency requirements than the primary data.

[0206] Preferably, the system is configured such that the latency limit of the main data is approximately equivalent to a network beacon interval.

[0207] Preferably, the primary data includes audio channel data. The audio channel data may include data output from the system microphone or accelerometer, or data to be played from the system speakers. The audio channel data may also include data used as part of a road noise cancellation system.

[0208] Alternatively, the primary data may include other non-audio low-latency data, which may be isochronous.

[0209] Preferably, the auxiliary data includes network control data, such as Ethernet data.

[0210] Preferably, the transmission rate of the network beacon is based on the latency requirements of low-latency data. For example, for a system where the main data is audio data, the transmission rate of the network beacon can be based on the audio sampling rate.

[0211] Preferably, the communication network includes at least one parent node and multiple child nodes. Preferably, the communication network is configured as a multipoint network, wherein multiple devices are connected to a single network bus.

[0212] Preferably, the auxiliary data includes Ethernet frames to be transmitted by devices on the network.

[0213] Ethernet frames can be transmitted across multiple beacon cycles without interrupting the normal transmission of low-latency data after the network beacon transmission.

[0214] Preferably, the network beacon can be selected from: a low-latency beacon used to mark the start of the main data within a beacon period; or a data period beacon used to mark the start of the auxiliary data frame period transmitted across a series of beacon periods on the network, while also marking the start of the main data within the beacon period.

[0215] It should be understood that data periodic beacons can be provided as a special case of low-latency beacons.

[0216] Preferably, the network node is configured to use a pass frame as an auxiliary data transmission, for example, when the network node has no data to transmit.

[0217] Preferably, when all network nodes on the network have transmitted yield frames, the data period beacon is transmitted as the next network beacon to define the start of a new auxiliary data frame period.

[0218] Preferably, the communication network includes a multipoint twisted-pair bus arranged for half-duplex data transmission.

[0219] Preferably, the main data is transmitted from the network node as data microframes.

[0220] Preferably, the main data includes a header segment to distinguish microframes from ordinary data frames, for example, for transmitting auxiliary data.

[0221] Preferably, the network beacon is used for the restoration and / or synchronization of the system clock by the system's network nodes.

[0222] A network node for use in the aforementioned communication network is also provided. The network node may be equipped with a data port and a transceiver, the transceiver communicating with the network bus via the data port.

[0223] In one aspect, the network node is provided as an integrated circuit (or IC) including a transceiver module and a data port as described above, as well as an auxiliary module for outputting signals based on data received by the transceiver module.

[0224] Preferably, the auxiliary module includes an integrated amplifier module for driving the transducer (preferably an audio transducer or a speaker). It should be understood that the integrated amplifier module can be arranged to drive the haptic transducer.

[0225] In terms of alternatives, for example, if the transceiver module and the amplifier module are manufactured using different processes, the IC can be provided as a co-packaged transceiver module and amplifier module.

[0226] Alternatively, the network node can be provided as a standalone transceiver IC, which is arranged to be coupled to discrete auxiliary ICs, such as separate amplifiers, audio codecs, separate controller ICs, etc.

[0227] Preferably, the network node includes a phase-locked loop (PLL) arranged to generate a clock signal at the network node, wherein the clock signal is generated based on a network beacon received by the network node.

[0228] A vehicle comprising the system and method described above is also provided.

[0229] The systems and / or integrated circuits described above with reference to the accompanying drawings may be incorporated into a vehicle, for example, as part of an audio system or component of an automobile, truck, boat or other vehicle, or as part of an RNC system or component of an automobile, truck or other road vehicle, or incorporated into another host device, such as an electronic musical instrument system or component, a commercial audio system or component, a sound reinforcement system or component, an industrial data communication system or component, a laptop computer, a notebook computer, a netbook computer or a tablet computer, a gaming device such as a game console or a controller for a game console, a virtual reality (VR) or augmented reality (AR) device, a mobile phone, a portable audio player or some other portable device, or may be incorporated into an accessory device for use with a laptop computer, notebook computer, netbook computer or tablet computer, a gaming device, a VR or AR device, a mobile phone, a portable audio player or some other portable device.

[0230] Those skilled in the art will recognize that some aspects of the aforementioned devices and methods can be embodied, for example, on non-volatile media such as disks, CD-ROMs, or DVD-ROMs, programmable memories (such as read-only memory (firmware)), or on data carriers such as optical or electrical signal carriers. For many applications, embodiments of the invention will be implemented on a system-on-a-chip (SoC), DSP (digital signal processor), ASIC (application-specific integrated circuit), or FPGA (field-programmable gate array). Therefore, the code may include conventional program code or microcode, or, for example, code for setting up or controlling an ASIC or FPGA. The code may also include code for dynamically configuring reconfigurable devices (such as reprogrammable logic gate arrays). Similarly, the code may include code for hardware description languages ​​(such as Verilog™ or VHDL (Very High Speed ​​Integrated Circuit Hardware Description Language)). As those skilled in the art will understand, the code may be distributed among multiple coupled components that communicate with each other. Where appropriate, the embodiments may also be implemented using code that runs on a field-programmable analog array or similar device to configure analog hardware.

[0231] It should be noted that, as used herein, the term "module" will be used to refer to a functional unit or block that can be implemented at least in part by dedicated hardware components (such as custom circuit systems) and / or at least in part by one or more software processors or appropriate code running on a suitable general-purpose processor. A module itself may include other modules or functional units. A module may be provided by multiple components or submodules that do not need to be co-located but can be located on different integrated circuits and / or run on different processors.

[0232] As used herein, in cases where two or more elements are referred to as “coupled” to each other, this term indicates, if applicable, whether the connection is indirect or direct, with or without intervening elements, that the two or more elements are in electronic or mechanical communication.

[0233] This disclosure covers all changes, substitutions, variations, alterations, and modifications to the exemplary embodiments herein that will be understood by those skilled in the art. Similarly, where appropriate, the appended claims cover all changes, substitutions, variations, alterations, and modifications to the exemplary embodiments herein that will be understood by those skilled in the art. Furthermore, references in the appended claims to a device or system or a component of a device or system adapted to, arranged to, capable of, configured to, enabled, operable, or operated to perform a particular function cover such device, system, or component, whether or not it or the particular function is activated, turned on, or unlocked, provided that the device, system, or component is so adapted, arranged, capable of, configured, enabled, operable, or operated. Therefore, modifications, additions, or omissions may be made to the systems, devices, and methods described herein without departing from the scope of this disclosure. For example, components of a system and device may be integrated or separate. Furthermore, the operation of the systems and devices disclosed herein may be performed by more, fewer, or other components, and the described methods may include more, fewer, or other steps. Additionally, the steps may be performed in any suitable order. As used in this document, “each” means each member of a set or each member of a subset of a set.

[0234] While exemplary embodiments are shown in the accompanying drawings and described below, the principles of this disclosure can be implemented using any number of techniques, whether currently known or not. This disclosure should in no way be limited to the exemplary implementations and techniques shown in the accompanying drawings and described above.

[0235] Unless otherwise expressly stated, the items depicted in the accompanying drawings are not necessarily drawn to scale.

[0236] All examples and conditional language described herein are intended for pedagogical purposes to help the reader understand this disclosure and the concepts contributed by the inventors to facilitate the technology, and are not to be construed as being limited by such specific examples and conditions. While embodiments of this disclosure have been described in detail, it should be understood that various changes, substitutions, and modifications may be made to the described embodiments without departing from the spirit and scope of this disclosure.

[0237] While specific advantages have been listed above, various embodiments may include some or all of the listed advantages, or may not include them. Furthermore, other technical advantages may become apparent to those skilled in the art upon review of the foregoing figures and description.

[0238] It should be noted that the above embodiments are illustrative and not limiting of the invention, and many alternative embodiments will be able to be devised by those skilled in the art without departing from the scope of the appended claims. The word "comprising" does not exclude the presence of elements or steps other than those listed in the claims, "an" or "a" does not exclude a plurality, and a single feature or other unit may perform the function of several units recited in the claims. No reference numerals or labels in the claims should be construed as limiting their scope.

Claims

1. A system for transmitting primary data and auxiliary data, the system comprising: bus; Coupled to the parent node of the bus; as well as Each is coupled to multiple child nodes of the bus. in: The parent node is configured to periodically transmit a Time Domain Multiplexing (TDM) periodic beacon to the bus, wherein the TDM periodic beacon signals the start of a major data transmission interval, and wherein the major data transmission interval is a period reserved for the transmission of major data by the parent node and the plurality of child nodes; Each of the parent node and the plurality of child nodes is capable of transmitting, in response to the TDM periodic beacon, the main data of the current TDM beacon period associated with the TDM periodic beacon to the bus during the main data transmission interval; and The parent node and the plurality of child nodes are operable to transmit auxiliary data to the bus during the auxiliary data transmission interval between the end of the main transmission interval and the transmission of the next TDM cycle beacon by the parent node.

2. The system of claim 1, wherein the primary data has a higher priority than the auxiliary data.

3. The system of claim 1 or claim 2, wherein the primary data is isochronous data associated with a first delay requirement and the auxiliary data is associated with a second delay requirement, wherein the first delay requirement is more stringent than the second delay requirement.

4. The system as claimed in any of the preceding claims, wherein the parent node is further configured to transmit a data periodic beacon instead of the TDM periodic beacon, wherein the data periodic beacon is indicated by a signal: The start of the main data transmission interval; and The start of the auxiliary data frame period, The auxiliary data frame period provides each of the parent node and the plurality of child nodes with an opportunity to transmit an auxiliary data frame to the bus.

5. The system of any one of claims 2 to 5, wherein the primary data includes audio data and the secondary data includes Ethernet data.

6. The system of claim 5, wherein the parent node is configured to transmit a TDM periodic beacon during each sampling period of the audio data.

7. The system as claimed in any of the preceding claims, wherein the TDM periodic beacon comprises a first specific symbol combination used in 10Base-T1S Ethernet.

8. The system as claimed in any of the preceding claims, wherein each of the parent node and each of the plurality of child nodes is configured to transmit its primary data in a respective primary data microframe.

9. The system of claim 8, wherein the primary data microframe comprises: Header; One or more key data samples from the current TDM beacon period; as well as End-of-frame delimiter.

10. The system of claim 9, wherein the main data microframe further includes a scrambler synchronization sequence.

11. The system of claim 8 or claim 9, wherein the header includes a second specific combination of symbols used in 10Base-T1S Ethernet.

12. The system of any one of claims 8 to 10, wherein the parent node and the plurality of child nodes are configured to transmit their respective primary data microframes in a predefined primary data transmission order.

13. The system of claim 12, wherein the parent node and the plurality of child nodes are configured to achieve minimal latency between the transmission of TDM periodic beacons and the transmission of the parent node’s main data frames, and between the transmission of their respective main data microframes in a predefined main transmission order.

14. The system of claim 12 or claim 13, wherein the parent node and the plurality of child nodes are configured to implement random or pseudo-random delays between the transmissions of their respective major microframes.

15. The system of any one of claims 12 to 14, wherein each of the parent node and each of the plurality of child nodes is operated to determine the correct point for transmitting its primary data microframe within the primary data transmission interval by determining the following: The byte or time offset from the TDM periodic beacon; or The number of transmissions that have occurred on the bus since the transmission of the TDM periodic beacon.

16. The system of any one of claims 4 to 15, wherein if each of the parent node and each of the plurality of child nodes has no auxiliary data frames to transmit, they operate to transmit a yield signal to the bus.

17. The system as claimed in any one of claims 4 to 16, wherein: The auxiliary data frame period provides a corresponding transmission opportunity window for each of the parent node and the plurality of child nodes, within which the parent node or the child node can transmit an auxiliary data frame to the bus; and Each of the parent node and the plurality of child nodes operates to maintain the correct timing of the transmission of its respective auxiliary data frames.

18. The system of claim 17, wherein: The auxiliary data frame period provides a corresponding transmission opportunity window for each of the parent node and the plurality of child nodes, and the parent node or the child node can transmit an auxiliary data frame to the bus within the window; Each of the parent node and each of the plurality of child nodes includes a transmission opportunity counter that operates to count transmission opportunities since the transmission of the data periodic beacon, wherein each of the plurality of child nodes operates to determine when to transmit its respective auxiliary data frame based on the value of its respective transmission opportunity counter. Each of the parent node and the plurality of child nodes operates to adjust its respective transmission opportunity counter in response to the transmission of auxiliary data frames by the parent node or child node. If none of the plurality of child nodes has an auxiliary data frame to transmit, the child node operates to not transmit a signal to the bus. The parent node operates to transmit a transmission opportunity increment signal to the bus when it detects that the transmission opportunity window has passed but no auxiliary data frame has been transmitted; and Each of the plurality of child nodes operates to adjust its corresponding transmission opportunity counter in response to the detection of a transmission opportunity increment signal.

19. The system of claim 18, wherein: If the transmission opportunity window will pass within a predefined time period before the scheduled transmission of the next TDM cycle beacon, the parent node operates to delay the transmission of the transmission opportunity increment signal until after the end of the main data transmission interval of the next TDM cycle period associated with the next TDM cycle beacon.

20. The system of claim 18 or claim 19, wherein: The parent node operates in response to its transmission opportunity counter reaching a predefined value by not transmitting the transmission opportunity increment signal, but instead transmitting a new data cycle beacon instead of the next TDM cycle beacon.

21. The system of any one of claims 4 to 20, wherein the data periodic beacon comprises a third specific symbol combination used in 10Base-T1S Ethernet.

22. The system of any one of claims 4 to 21, wherein if the length of the auxiliary data frame is greater than the length of the auxiliary data transmission interval, the node transmitting the auxiliary data frame operates to segment the auxiliary data frame within a multi-TDM beacon period.

23. The system of claim 22, wherein the node transmitting the auxiliary data frame operates to: Pause the transmission of the auxiliary data frame; and After the main transmission period of the next TDM beacon period ends, the transmission of the auxiliary data frames resumes.

24. The system of claim 23, wherein the node transmitting the auxiliary data frame operates to pause the transmission of the auxiliary data frame at its octet boundary.

25. The system of claim 23 or claim 24, wherein the node transmitting the auxiliary data frame operates to: The transmission includes a pause signal comprising a fourth specific symbol combination used in 10Base-T1S Ethernet, to signal a pause in the transmission of the auxiliary data frame; and During the next TDM beacon period, a recovery signal comprising the fifth specific symbol combination used in 10Base-T1S Ethernet is transmitted to indicate the resumption of the transmission of the auxiliary data frame.

26. The system of any one of claims 4 to 25, wherein the parent node and the plurality of child nodes are configured to implement random or pseudo-random delays in the transmission timing of their respective auxiliary data frames.

27. The system as claimed in any of the preceding claims, wherein the parent node operates to impose a random or pseudo-random delay on the transmission of the TDM beacon signal.

28. The system of claim 27, wherein the parent node operates to associate a randomized value indicating the duration of the random or pseudo-random delay with the TDM beacon signal.

29. The system of claim 28, wherein the random or pseudo-random delay is based on a random probability density function (RPDF) or a triangular probability density function (TPDF) with variable amplitude.

30. The system of any one of claims 4 to 29, wherein the parent node and / or at least one of the plurality of child nodes includes a clock recovery system configured to generate a clock signal based on the TDM periodic beacon signal and / or the data periodic beacon.

31. The system of claim 30, wherein the clock recovery system is configured to generate a TDM periodic beacon detection signal in response to detecting the TDM periodic beacon or the data periodic beacon, wherein the clock recovery system includes a phase-locked loop (PLL) configured to use the TDM periodic beacon detection signal as a frequency and phase reference to generate the clock signal.

32. The system as claimed in any of the preceding claims, wherein the communication network comprises a multi-point communication network.

33. The system as claimed in any of the preceding claims, wherein the bus comprises a twisted-pair cable.

34. The system as claimed in any of the preceding claims, wherein the bus is configured to transmit power to one or more of the plurality of child nodes.

35. A road noise cancellation system comprising the system as described in any of the preceding claims, wherein at least one of the plurality of sub-nodes comprises a microphone node or an accelerometer node, and wherein the primary data comprises road noise cancellation audio sample data generated by the microphone node or accelerometer data generated by the accelerometer node.

36. A method for transmitting primary data and secondary data in a communication network, the communication network comprising a bus, a parent node coupled to the bus, and a plurality of child nodes coupled to the bus, the method comprising: The parent node periodically broadcasts a TDM periodic beacon signal, which defines the start of the main data transmission interval, wherein the main data transmission interval is a period reserved for the transmission of main data by the parent node and the plurality of child nodes; In response to the TDM periodic beacon signal, the parent node and / or at least one of the plurality of child nodes transmits primary data to the bus during the primary data transmission interval; as well as An auxiliary data transmission interval is provided between the expiration of the primary data transmission interval and the broadcast of the next TDM cycle beacon signal by the parent node. This auxiliary data transmission interval is a period reserved for the transmission of auxiliary data by the parent node and / or the plurality of child nodes.

37. An isochronous data transceiver for a node in a system as described in any one of claims 1 to 34, wherein the isochronous data transceiver comprises: The processing circuit for implementing the framing engine includes a main data microframe processor and an auxiliary data frame processor. as well as An interface circuit for interfacing the isochronous data transceiver with the bus of the system. in: The primary data microframe processor is configured to transmit primary data microframes to the bus and receive primary data microframes from the bus via the interface circuit. The auxiliary data frame processor is configured to transmit auxiliary data frames to and receive auxiliary data frames from the bus via the interface circuitry; and The framing engine is capable of operating to generate the TDM periodic beacon and transmit it to the bus.

38. The isochronous data transceiver of claim 37, wherein the isochronous data transceiver is configured to: receive the TDM periodic beacon and / or the data periodic beacon, and generate a clock signal based on the TDM periodic beacon signal and / or the data periodic beacon.

39. The isochronous data transceiver of claim 37 or claim 38, wherein the isochronous data includes audio data.

40. An integrated circuit (IC) that implements the isochronous data transceiver as described in claim 37 or claim 38.

41. The IC of claim 40, wherein the IC further comprises an amplifier circuit.

42. A parent node or child node of a communication network, said communication network including an isochronous data transceiver as described in claim 37 or claim 38.

43. An integrated circuit that integrates a parent node of a system as claimed in any one of claims 1 to 34, wherein the integrated circuit operates to: Apply random or pseudo-random delays to the transmission of TDM beacon signals; and The randomized value indicating the duration of the random or pseudo-random delay is associated with the TDM beacon signal.

44. An integrated circuit that integrates a sub-node of a system as claimed in any one of claims 1 to 34, wherein the integrated circuit operates to: Receive TDM beacon signals with random or pseudo-random delays and associated randomization values; and Based on the received TDM beacon signal, the randomization value is used to generate a reference clock signal to compensate for the random or pseudo-random delay of the beacon signal.

45. A vehicle comprising the system as claimed in any one of claims 1 to 34.

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