Abstract: The present disclosure relates to a user equipment (UE) which comprises a transmitter that transmits at least one data packet based on a transmitting window having a transmitting window size. A receiver of the UE receives reception feedback regarding the at least one transmitted data packet. Processing circuitry of the UE determines, based on at least the received reception feedback, whether to change the transmitting window size for the transmitting window to be used at least for transmitting further data packets.

Abstract: A network device can include packet processing circuitry to provide support for virtual functions. The packet processing circuitry can perform operations such as receiving data traffic associated with a physical address, determining that the data traffic is associated with a guest of a host system by matching the data traffic with an ingress rule associated with a virtual function, and forwarding the data traffic to the virtual function.

Abstract: A system and method to transmit frames from a first node to a second node over a plurality of radio links comprising a classifier to classify said frames according to one of a plurality of flow and a sequence number within said one of said plurality of flow and adding said flow and sequence number in a header of said classified frame a splitter receiving said classified frames from said classifier and distributing said classified frames on one of said plurality of radio links for transmission to said second node, a joiner receiving said classified frames and reordering them using an indexed sequence queue corresponding to each of said plurality of flows, a timer for waiting for frames missing in the sequence in one of said indexed sequence queue, wherein when said timer expires, if said frame has not arrived it is deemed lost and a forwarder to extract frames from said sequence queue to forward.

Abstract: The present invention provides an image encoding method and an image decoding method. The image encoding method of the present invention comprises: a first dividing step of dividing a current image into a plurality of blocks; and a second dividing step of dividing, into a plurality of sub blocks, a block, which is to be divided and includes a boundary of the current image, among the plurality of blocks, wherein the second dividing step is recursively performed by setting a sub block including the boundary of the current images as the block to be divided, until the sub block including the boundary of the current image does not exist among the sub blocks.

Abstract: The present invention provides an image encoding method and an image decoding method. The image encoding method of the present invention comprises: a first dividing step of dividing a current image into a plurality of blocks; and a second dividing step of dividing, into a plurality of sub blocks, a block, which is to be divided and includes a boundary of the current image, among the plurality of blocks, wherein the second dividing step is recursively performed by setting a sub block including the boundary of the current images as the block to be divided, until the sub block including the boundary of the current image does not exist among the sub blocks.

Abstract: A user equipment for a mobile communication network is provided. The mobile communication network has a radio access network including a plurality of cells and being configured to serve the user equipment within a cell. To receive a data packet from the radio access network, the user equipment is configured to receive a plurality of different versions of the data packet transmitted by the radio access network to the user equipment in parallel via different physical resources. To provide a data packet to the radio access network, the user equipment is configured to provide a plurality of different versions of the data packet and to transmit the plurality of different versions of the data packet to the radio access network in parallel via different physical resources.

Abstract: In one embodiment, an apparatus includes a network interface to receive a sequence of data packets from a remote device responsively to a data transfer request, the received sequence including received data blocks, and packet processing circuitry to read cryptographic parameters from a memory in which the parameters were registered by a processing unit, the cryptographic parameters including an initial cryptographic key and initial value, compute a first cryptographic key responsively to the initial cryptographic key and initial value, cryptographically process a first block responsively to the first cryptographic key, compute an updated value responsively to the initial value and a size of the first block, compute a second cryptographic key responsively to the initial cryptographic key and the updated value, cryptographically process a second block of the received data blocks responsively to the second cryptographic key, and write the cryptographically processed first and second block to the memory.

Abstract: In one embodiment, data communication apparatus includes packet processing circuitry to receive data from a memory responsively to a data transfer request, and cryptographically process the received data in units of data blocks using a block cipher so as to add corresponding cryptographically processed data blocks to a sequence of data packets, the sequence including respective ones of the cryptographically processed data blocks having block boundaries that are not aligned with payload boundaries of respective one of the packets, such that respective ones of the cryptographically processed data blocks are divided into two respective segments, which are contained in successive respective ones of the packets in the sequence, and a network interface which includes one or more ports for connection to a packet data network and is configured to send the sequence of data packets to a remote device over the packet data network via the one or more ports.

Abstract: Technologies for scheduling time-sensitive cyclical network traffic in real-time include an internet-of-things (IoT) device that includes at least one sensor for collecting sensor data. The IoT device is configured to store the collected sensor data in a data buffer, allocate a packet descriptor for the sensor data, and populate the allocated packet descriptor with a cyclic data port pointer indicative of a location of the data buffer. The IoT device is additionally configured to queue the packet descriptor into a media access control (MAC) unit transmit direct memory access (DMA) of the IoT device, fetch the sensor data, and packetize the fetched data to form a network packet. Further, the IoT device is configured to transmit the network packet to a target computing device based on a launch time, update the launch time, and requeue the packet descriptor into the MAC unit transmit DMA. Other embodiments are described herein.

Abstract: A communication apparatus for selecting a plurality of messages each including destination information indicating a common transmission destination from among a plurality of messages each including destination information indicating a transmission destination, a first generation unit configured to generate a plurality of transmission packets corresponding to the messages selected, in a batch, and a second generation unit configured to generate a transmission packet corresponding to a message not selected among the plurality of messages.

Abstract: The present invention provides an image encoding method and an image decoding method. The image encoding method of the present invention comprises: a first dividing step of dividing a current image into a plurality of blocks; and a second dividing step of dividing, into a plurality of sub blocks, a block, which is to be divided and includes a boundary of the current image, among the plurality of blocks, wherein the second dividing step is recursively performed by setting a sub block including the boundary of the current images as the block to be divided, until the sub block including the boundary of the current image does not exist among the sub blocks.

Abstract: A master station device includes a processor that outputs a subcarrier modulation signal, and a transmitter that maps an in-phase (I) component and a quadrature-phase (Q) component of the subcarrier modulation signal to an optical signal to be transmitted to a fronthaul.

Abstract: Example embodiments describe an optical line terminal, OLT, configured to perform determining a fragmentation allocation for respective ONUs; and notifying, the respective ONUs, of the fragmentation allocation. Other example embodiments relate to an optical network unit, ONU, configured to perform receiving, from the OLT, fragmentation allocation for fragmenting one or more packets; processing the packets in accordance with the fragmentation allocation to obtain fragmented and unfragmented packets; and forwarding, to the OLT, the fragmented and unfragmented packets in accordance with the dynamic upstream allocation map.

Abstract: A communication management resource such as associated with or at a first wireless access point monitors a corresponding backhaul providing connectivity between the first wireless access point and a remote network. Based on the monitoring of the backhaul, the communication management resource produces status information indicating a status such as ability of the backhaul to convey data communications between the first wireless access point and the backhaul. The first wireless access point then controls wireless connectivity between the first wireless access point and a mobile communication device based on the status of the backhaul.

Abstract: Systems, methods, computer-readable media, techniques, and methodologies are disclosed for detecting messages received sequentially in short succession and implementing delivery controls to control a timing of the delivery of content of the messages for presentation to a user. Message detection and delivery control mechanisms disclosed herein refrain from presenting the content of multiple messages received in quick succession until a delivery event condition is detected. Upon detection of the delivery event condition, the content of the messages is consolidated into a message digest that is presented to a user (e.g., an intended recipient of the messages). The consolidated message digest can be presented to the user via an output interface, such as an in-vehicle speaker or display. In this manner, both disruption to the user experience as well as potential safety concerns, particularly in an in-vehicle environment, are mitigated by reducing the number and frequency of messages that are consumed.

Abstract: In accordance with some embodiments, a method may include transmitting, by a source network entity, at least one handover prepare request comprising at least one extension indication to a target network entity. The method may further include receiving, by the source network entity, in response to the at least one handover prepare request, at least one handover request response from the target network entity. The method may further include transmitting, by the source network entity, at least one handover command acknowledgement to at least one user equipment based upon the at least one handover request response.

Abstract: A time-division multiplexing (TDM) scheduler determines a service order for serving N packet transmission requesters. The TDM scheduler includes: N current count value generators configured to serve the N packet transmission requesters respectively, and generate N current count values according to parameters of the N packet transmission requesters, a previous scheduling result generated by the EDD scheduler previously, and a predetermined counting rule; and an earliest due date (EDD) scheduler configured to generate a current scheduling result for determining the service order according to the N current count values and a predetermined urgency decision rule, wherein an extremum of the N current count values relates to one of the N packet transmission requesters, and the EDD scheduler selects this requester as the one to be served preferentially.

Abstract: An apparatus, method, and computer-readable recording medium perform local client device data throttling in a wireless network. A network controller of a gateway device allocates a portion of a periodic allocation of data available from an ISP cycle to one or more client devices connected to the gateway device. The gateway device sets a threshold for each client device and monitors bandwidth data consumption for each of the client devices. When a particular client device reaches its assigned bandwidth data allotment, the gateway device throttles data to the client device until a new periodic allocation of data is available from the ISP. While a particular client device is throttled, when a guest device joins the network or a particular client device accesses a prestored URL address, the gateway device may reallocate allotted data from one client device to another as needed to maintain operation of the wireless network.

Abstract: The present invention provides an image encoding method and an image decoding method. The image encoding method of the present invention comprises: a first dividing step of dividing a current image into a plurality of blocks; and a second dividing step of dividing, into a plurality of sub blocks, a block, which is to be divided and includes a boundary of the current image, among the plurality of blocks, wherein the second dividing step is recursively performed by setting a sub block including the boundary of the current images as the block to be divided, until the sub block including the boundary of the current image does not exist among the sub blocks.

Abstract: A method for synchronous processing exchange orders, comprising: creating a first batch of orders by accumulating exchange orders received within a first time period, TP1; creating a second batch of orders by accumulating exchange orders received within a second time period, TP2; and processing the orders from the first batch within the second time period, TP2.

Abstract: A thread executing a task at a node in a multi-socket computing system may access a first data structure to obtain a first calibration dataset for the node. The first thread may generate a timestamp based on the first calibration dataset and a first quantity of time measured by a clock at the first node. The real-time duration of the task may be determined based on the timestamp. The first thread may recalibrate the first clock by at least generating, based on the first quantity of time measured by the clock and a second quantity of time measured by a wall clock of an operating system of the multi-socket computing system, a second calibration dataset. The first thread may update the first data structure to include the second calibration dataset while a second thread accesses a second data structure to obtain calibration data.

Abstract: A clock synchronization packet exchanging method includes sending, by a first device in a Flexible Ethernet (FlexE) group, a first FlexE instance at a first physical layer (PHY), where the first FlexE instance includes a clock synchronization packet, and a second FlexE instance sent by the first device in the FlexE group at a second PHY also includes a clock synchronization packet. The clock synchronization packets are carried in a plurality of FlexE instances transmitted between a transmit end and a receive end in the FlexE group.

Abstract: A data processing platform, method, and program product perform compression and decompression of a set of data items. Suffix data and a prefix are selected for each respective data item in the set of data items based on data content of the respective data item. The set of data items is sorted based on the prefixes. The prefixes are encoded by querying multiple encoding tables to create a code word containing compressed information representing values of all prefixes for the set of data items. The code word and suffix data for each of the data items are stored in memory. The code word is decompressed to recover the prefixes. The recovered prefixes are paired with their respective suffix data.

Abstract: Embodiments of the present disclosure provide a software defined network publish-subscribe system and method. The software defined network publish-subscribe system comprises a controller, an administrator controller, a sequencing subsystem and a message multi-backup cache subsystem. The controller is configured to process publish-subscribe transactions in clusters, and comprises sequencing nodes used for generating ordered serial numbers for messages and cache nodes for caching the messages. The administrator controller is configured to simultaneously perform functions of the controller and manage software-defined network. The sequencing subsystem is configured to realize the cooperative sequencing between the administrator controller and the sequencing nodes. The message multi-backup cache subsystem is configured to realize the consistency of the messages through the administrator controller and the cache nodes.

Abstract: Wireless communication systems and methods related to Radio Link Control (RLC) status reporting are provided. A wireless communication device receives one or more radio link control (RLC) packet data units (PDUs) of a sequence of RLC PDUs. The wireless communication device determines missing RLC data PDUs in the sequence of RLC PDUs based on the received one or more RLC PDUs. The wireless communication device receives a first uplink (UL) grant. The wireless communication device transmits a first RLC status report including an indication of a first subset of the missing RLC PDUs less than all the missing RLC PDUs, the indication of the first subset of missing PDUs being based on a size of the first UL grant. The wireless communication device modifies a RLC status prohibit timer based on the transmitted first RLC status report indicating less than all the missing RLC PDUs.

Abstract: Methods and systems are disclosed for network communication. A computing device may store status information. The status information may be communicated using a first protocol. The status information may indicate data is available. The data may be communicated using a second protocol.

Abstract: There are provided a controller, an electronic system including the same, and an operating method of the controller and the memory system. The controller includes: a randomizing circuit configured to generate random data having a set number of bits; a masking circuit configured to output select random data by extracting some data according to a number of bits on which a partial encoding operation is to be performed, among the random data; an operating circuit configured to output encoded data and a portion of original data, by performing an operation sequentially on the original data and the select random data; and a cyclic redundancy check circuit configured to generate a cyclic redundancy check value by performing a cyclic redundancy check on the encoded data and the portion of original data, and output partially encoded data including the cyclic redundancy check value, the portion of original data, and the encoded data.

Abstract: Embodiments of a device and method are disclosed. In an embodiment, an Ethernet communications device includes a physical layer (PHY) unit or a media access control (MAC) unit configured to perform media access control for the Ethernet communications device. The Ethernet communications device includes a security unit configured to manipulate a data stream in a data path within the Ethernet communications device when the data stream violates or conforms to a pre-defined policy.

Abstract: The present invention provides an image encoding method and an image decoding method. The image encoding method of the present invention comprises: a first dividing step of dividing a current image into a plurality of blocks; and a second dividing step of dividing, into a plurality of sub blocks, a block, which is to be divided and includes a boundary of the current image, among the plurality of blocks, wherein the second dividing step is recursively performed by setting a sub block including the boundary of the current images as the block to be divided, until the sub block including the boundary of the current image does not exist among the sub blocks.

Abstract: High-speed processing of packets to, and from, a virtualization environment can be provided while utilizing hardware-based segmentation offload and other such functionality. A hardware vendor such as a network interface card (NIC) manufacturer can enable the hardware to support open and proprietary stateless tunneling in conjunction with a protocol such as single root I/O virtualization (SR-IOV) in order to implement a virtualized overlay network. The hardware can utilize various rules, for example, that can be used by the NIC to perform certain actions, such as to encapsulate egress packets and decapsulate packets.

Abstract: An encrypted tunnel is established between a virtual private network (VPN) server and a VPN user device. A request to establish a connection with a target device is received from the VPN user device. The request uses initial connection parameters. The connection the converted into a first connection between the VPN user device and the VPN server and a second connection between the VPN server and the target device. The first connection uses first connection parameters and the second connection uses second connection parameters. At least one parameter of the first connection parameters or of the second connection parameters is different from a corresponding parameter of the initial connection parameters. First network packets received from the VPN user device according to the first connection parameters are converted into second network packets according to the second connection parameters. The second network packets are transmitted to the target device.

Abstract: A first node in a TSCH network may receive a message-initiation packet from a second node on the TSCH network. Based on information in the message-initiation packet, the first node may determine a transmission time for a message content packet that is associated with the message-initiation packet. The first node may generate or modify a node-specific transmission delay that indicates a backoff associated with the second node. The node-specific transmission delay may indicate a quantity of backoff time slots during which the first node delays initiating a transmission with the second node. If the first node receives, during the node-specific transmission delay, an additional packet intended for the second node, the first node may queue the additional packet until after the node-specific transmission delay is completed.

Abstract: It is disclosed a method for enabling a performance measurement in a packet-switched communication network. A first node and a second node exchange packets comprising a marking value, which they alternately switch between two alternative marking values. The second node in particular switches the marking value applicable to the packets addressed to the other node depending on the marking value comprised in packets received therefrom. The first node writes a sampling value in one packet addressed to the second node for each marking period. Upon reception of each packet comprising the sampling value, the second node copies the sampling value in a packet addressed to the first node. One or more measurement points may be provided between the two nodes, which provide performance parameters for the packets comprising the sampling value in both directions. Such performance parameters may be used for providing round trip time measurements.

Abstract: A method, apparatus, computer program product and computer accessible code configured to link or otherwise associate content filters with a multimedia presentation, e.g., a movie. The content filter data includes an identifier value with an aspect ratio identifier or as a function of an aspect ratio for a particular multimedia presentation associated with the filter information. In one implementation, association between a filter set and a multimedia presentation involves a filtering application that searches a particular multimedia presentation to locate aspect ratio information and further searches filter information for a matching aspect ratio identifier.

Abstract: At least one first control message (2011) indicative of the remote node (103) and of timing information (351, 352) is communicated between a network and a relay node (102). At least one second control message (2012) is communicated via a device-to-device, D2D, channel of the wireless link and between the relay node (102) and the remote node (103) in accordance with the timing information (351, 352). The at least one second control message is indicative of the network paging the remote node (103).

Abstract: Based on a count value held by a transmission counter, an information multiplex apparatus forms multiplexed transmission data by selecting or dividing at least part of each of two or more information items, based on the respective sizes of the two or more information items, a counter period of the transmission counter, and a transmission margin degree.

Abstract: According to one or more of the embodiments herein, systems and techniques for using satellite diversity for enhancing communication confidentiality are provided. In particular, a system in accordance with the techniques herein enhances the security of encrypted messages transmitted over a secure channel, specifically through the use of satellite communications diversity to securely deliver secret messages from a sender to a recipient, ensuring message confidentiality. That is, the techniques herein provide secure message communication over satellites, particularly with additional message security in the presence of an eavesdropping adversary party by segmenting the message and sending the various message segments over different diverse paths.

Abstract: Disclosed is a time-division multiplexing (TDM) scheduler capable of determining a service order for serving N packet transmission requesters. The TDM scheduler includes: N current count value generators configured to serve the N packet transmission requesters respectively, and generate N current count values according to parameters of the N packet transmission requesters, a previous scheduling result generated by the EDD scheduler previously, and a predetermined counting rule; and an earliest due date (EDD) scheduler configured to generate a current scheduling result for determining the service order according to the N current count values and a predetermined urgency decision rule, wherein an extremum of the N current count values relates to one of the N packet transmission requesters, and the EDD scheduler selects this requester as the one to be served preferentially.

Abstract: In one embodiment, data communication apparatus includes a network interface for connection to a network and configured to receive a sequence of data packets from a remote device over the network, the sequence including data blocks, ones of the data blocks having block boundaries that are not aligned with payload boundaries of the packets, and packet processing circuitry to cryptographically process the data blocks using a block cipher so as to write corresponding cryptographically processed data blocks to a memory, while holding segments of respective ones of the received data blocks in the memory, such that the packet processing circuitry stores a first segment of a data block of a first packet in the memory until a second packet is received, and then cryptographically processes the first and second segments together so as to write a corresponding cryptographically processed data block to the memory.

Abstract: A system and method to transmit frames from a first node to a second node over a plurality of radio links comprising a classifier to classify said frames according to one of a plurality of flow and a sequence number within said one of said plurality of flow and adding said flow and sequence number in a header of said classified frame a splitter receiving said classified frames from said classifier and distributing said classified frames on one of said plurality of radio links for transmission to said second node, a joiner receiving said classified frames and reordering them using an indexed sequence queue corresponding to each of said plurality of flows, a timer for waiting for frames missing in the sequence in one of said indexed sequence queue, wherein when said timer expires, if said frame has not arrived it is deemed lost and a forwarder to extract frames from said sequence queue to forward.

Abstract: The system or device may build one or more data packets by dividing a given payload for a packet into data blocks and inserting data checks for each data block sequentially into the packet payload. The device may generate, for each of the data blocks, a corresponding data check block corresponding to data in each data block. The device may send or arrange the data blocks and the corresponding data check blocks such that each of the data blocks is followed by the corresponding error check block in the packet. Using the corresponding check block, each of the data blocks is independently verifiable, so that the data blocks may be used upon receipt, even if the payload is not completely received.

Abstract: A method for calculating a communication time between a first and second devices includes: adding, to a first packet, first timer information indicating an elapsed time from activation of the first device, and transmitting the first packet; transmitting notification information including the first timer information and second timer information indicating an elapsed time from activation of the second device; transmitting a second packet including the first and second timer information, third timer information indicating an elapsed time from activation of the second device, and first time information indicating a time in the second device; and calculating a communication time from the first device to the second device based on the first timer information, the second timer information, the third timer information, and the first time information, fourth timer information indicating an elapsed time from activation of the first device, and second time information indicating a time in the first device.

Abstract: The present disclosure relates to a pre-5th-generation (5G) or 5G communication system to be provided for supporting higher data rates beyond 4th-generation (4G) communication system such as a long term evolution (LTE). A method for communication by a base station is provided. The method includes transmitting a scheduling assignment including a first part of a destination identifier (ID), and transmitting a medium access control (MAC) protocol data unit (PDU) including a MAC header including a user equipment (UE) ID and a second part of the destination ID.

Abstract: Techniques are disclosed relating to time synchronization in a network. In some embodiments, an apparatus includes a first circuit having a first clock configured to maintain a local time value for a node coupled to a network. The first circuit is configured to send a first message to a second circuit. The first message includes a first nonce. The second circuit has a second clock that maintains a reference time value for the network. The first circuit receives a second message from the second circuit, the second message including a second nonce and is associated with a timestamp identifying the reference time value. The first circuit compares the first nonce to the second nonce to determine whether the timestamp is valid and, in response to determining that the timestamp is valid, uses the timestamp to synchronize the first clock with the second clock.

Abstract: Described is a method of processing data packets in a communications network. The method comprises receiving a first data packet of a data packet flow from a network device and determining an instruction set for processing said first data packet. A flow key for said first data packet is determined. The first data packet is processed according to the determined instruction set. The method includes receiving a subsequent data packet and determining if a flow key of said subsequent data packet matches said flow key of said first data packet. If yes, the subsequent data packet is processed using the instruction set determined for said first data packet.

Abstract: Disclosed are methods and systems for a Bluetooth Low Energy (BLE) receiver to reduce the number of retransmission of packets needed to receive an error free packet so as to improve channel throughput. Techniques to reduce the number of retransmissions include a combination of processing of the header of the received packets to increase the number of corrupted packets available for reconstructing the original payload and bit error correction (BEC) of the payload of the corrupted packets. Header processing may include making available for payload reconstruction a packet whose received access address differs by no more than 1-bit from an assigned address of the receiver provided at least one of the corrupted packets used in the reconstruction contains an error-free access address. Header processing may also include using a prior error-free decoded length of the packet to aid in the determination of the length field of a current packet.

Abstract: A computer-implemented method includes positioning a sliding window over a string of data and calculating a hash value using a rolling hash function for data encompassed by the sliding window. The method includes determining whether the calculated hash value for the data encompassed by the sliding window matches the value of an element in a cut point candidate (CPC) array by comparing the calculated hash value to the value of a first element in the CPC array. In response to the calculated hash value being equal to the value of the first element in the CPC array, the method includes defining an index of the sliding window as the cutting point for a data block.

Abstract: A bridge chip receives a first data stream compliant with the first multimedia communication standard. The first data stream includes first video data of a first incoming video frame, second video data of a second incoming video frame, and information describing a transfer function for the second video data, the information included in a video blanking interval of the first incoming video frame. The bridge chip extracts information describing a transfer function for the second video data. The bridge chip then generates a second data stream compliant with the second multimedia communication standard. The second data stream includes the first video data in a first outbound video frame, the second video data in a second outbound video frame, and the extracted information describing the transfer function for the second video data. Finally, the generated second data stream is transmitted to a destination device.

Abstract: Methods, non-transitory computer readable media, network traffic management apparatuses, and network traffic management systems that monitor one or more messages generated by an application or one or more characteristics of one or more transmission control protocol (TCP) connections with a destination device or a source device. A determination is made when a first TCP push flag should be set for a first packet associated with data based on the monitoring. The data is provided by the application. The first TCP push flag for the first packet is set prior to the first packet being sent to the destination device via a first one of the TCP connections, based on the determination that the first TCP push flag should be set for the first packet. Accordingly, this technology more effectively manages TCP push functionality to reduce acknowledgement messages (ACKs) and thereby improve network bandwidth and device resource utilization.

Abstract: Embodiments described herein provide a method for providing a compatible backplane operation mechanism for 2.5-gigabit Ethernet. A first input of data including a first sequence-ordered set in compliance with a first interface protocol is received from a medium access control (MAC) layer. The first input of data is encoded into four outputs of encoded data including a second sequence-ordered set in compliance with a second interface protocol. The first sequence-ordered set in a first form of a sequence code followed by three bytes of data is mapped to the second sequence-ordered set in a second form of consecutive units of the sequence code followed by an encoded data byte. The four parallel outputs of encoded data are serialized into a serial output. The serial output to a linking partner is transmitted on a physical layer of an Ethernet link at a speed specified in the second interface protocol.