38results about How to "Ensure real-time communication" patented technology

The invention discloses a vehicle network integration technology-based electric vehicle charging system and an implementation method thereof. The electric vehicle charging system comprises an electric vehicle network mobile computing terminal, which establishes a connection with an intelligent electric network via a power line carrier modulation and demodulation module, is connected with a cloud computing remote service platform, and uploads vehicle information of electric vehicles to the cloud computing remote service platform; the cloud computing remote service platform transmits charging information to positioning practicable charging station information and the electric vehicle network mobile computing terminal; electric vehicles are in information interaction via vehicle-mounted electric vehicle mobile computing terminals; and a microwave power transmission device is arranged in a charging station. The implementation of the invention is based on an electric vehicle technology integrating a vehicle intranet and a vehicle outer net; the vehicle intranet is large in information transmission capacity, is communicated with transport facilities via the wireless communication manner of a power line carrier; and the real-time performance of communication on the premises of multiple networks and larger data capacity is ensured.

The invention belongs to the field of remote control and artificial intelligence and relates to an intelligent adjuvant therapy robot device for performing real-time social capability training for autism children. The device comprises a head movement driver (1), an arm movement driver (2), a device loader (3), a driving-driven wheel type chassis (4) and a casing module (7). A multi-joint combined driving mode is adopted, the collaborated driving capability of the robot for every movement joint is improved, the problem that time delay affects the interaction effect is solved, precise posture control of the robot in the random direction is achieved, a limb movement path planning function for automatically avoiding obstacles is achieved, and intelligent emotion interaction between a human and the robot and a safe and reliable family remote rehabilitation therapy model are achieved in various modes such as voice, images, touch and induction in the man-machine interactive process in response to emotion cognitive disorder which occurs universally in child patients.

The invention discloses a multi-data fusion meteorological prediction early warning method, and the method comprises the steps: carrying out the assimilation of meteorological observation data througha multi-source 4D-WRF-EnSRF data assimilation system, enabling the assimilation data to serve as the input of a DeepConvLSTMs artificial intelligence prediction network, and achieving the training ofthe network and the real-time rainfall prediction of multiple data sources; finely dividing rainfall intervals, and setting early warning levels; seamlessly dividing the coverage area of each mobilemeteorological station; and planning a mobile meteorological station, a meteorological monitoring center, a multi-means publishing platform and a prediction and early warning information publishing system, and guaranteeing real-time linkage of the system architecture. Multi-data acquisition and fusion are realized, prediction and early warning results are uploaded and issued in real time, a to-be-rescued area is rapidly locked, a rescue scheme is issued, and rescue field communication is ensured; the weather forecasting and early warning timeliness and accuracy are improved, the early warninginformation publishing coverage rate is increased, the weather disaster prevention and reduction service capacity and the rescue capacity are enhanced, and life and property losses caused by rainstormdisasters and secondary derivative disasters of the rainstorm disasters are effectively reduced.

The invention discloses a rapid synchronous phasor correction method which involves an initialization module, a synchronous sampling module, a phasor computation module, a phasor correction module, a phasor FIFO buffer area read-write interface module and a CPU compensation module. The rapid synchronous phasor correction method has the advantages that through the capacity of high-speed parallel computing of an FPGA, the data synchronous sampling process, recursive DFT operation and a phasor filter algorithm are finished in the FPGA, so that a CPU is released from frequent sampling interruption and the heavy DFT operation process, the main task is focused on response to commands of a master station, and communication instantaneity of a PMU is guaranteed. Meanwhile, the phasor filter algorithm is optimized through a DA algorithm, more-digit multiplication of long bytes can be carried out synchronously, and the computational speed is greatly improved.

The invention discloses a processing method and device for application programs in a terminal. The method comprises the steps that a communication request of the application programs in the terminal is monitored; a progress in the terminal is called; the communication request is sent to servers corresponding to the application programs through the progress, and long connection between the progress and the servers is established; responding information, for the communication request, returned by the servers is received and sent to the application programs through the progress. According to the technical scheme, the long connection between all the application programs and the corresponding servers thereof can be established and maintained through the progress, and it is ensured that when the application programs are closed, the long connection between the application programs and the corresponding servers thereof does not disappear accordingly; meanwhile, communication instantaneity between the application programs and the corresponding servers thereof can also be ensured, and the power consumption of a system can be reduced.

The invention provides a multi-path routing method based on a resource leveling strategy and applicable to an industrial wireless sensor network, and relates to the industrial wireless sensor network. According to the routing method, the concept of cross-layer design is adopted, comprehensive evaluation is carried out on data receiving and transmitting energy loss of a physical layer and forward queue memory loss of a network layer, and a route priority judgment strategy based on resource leveling factors is disclosed. Meanwhile, with the combination of a breadth-first search algorithm, multiple redundant routes between a data source node and destination nodes are calculated, the requirement for leveling node resources of the industrial wireless sensor network is met, and reliability of communication between the source node and the destination nodes is also improved. An ISA100.11a network is taken as an example, when a system manager in the ISA100.11a network carries out routing path calculation, a preferential path and multiple alternative paths are calculated on the basis of the topology of the current network and resource consumption situations of the sensor nodes, and routing information is distributed and stored in the nodes of the paths, and routing configuration is finished. As is proved, the method is feasible and can reach predicted effects.

The invention relates to the technical field of VR, especially to a wireless VR helmet based on a high-performance host. The wireless VR helmet comprises a helmet body, a wireless audio-video sending end, a wireless audio-video receiving end and a display screen, the wireless audio-video sending end comprises a coding unit and a wireless audio-video sending module, the wireless audio-video receiving end comprises a wireless audio-video receiving module and a decoding unit, and the decoding unit is connected with the display screen via an MIPI or LVDS interface. According to the invention, the VR helmet is no longer connected with the host in a wired manner due to use of a wireless communication technology, a user can walk freely in a larger space without limit of cables when using the wireless VR helmet, and the VR experience is improved; and graphs and computing resources in the host are fully utilized, signals of a signal source is decompressed in a compression-free or real-time compression manner, the communication instantaneity is ensured, and thus, dazzling caused by time delay is reduced.

The invention discloses an electric power LTE wireless terminal remote online monitoring method, the method comprises the following steps: (1) by a wireless terminal remote management system, receiving heartbeat request message reported by a wireless terminal; (2) updating heartbeat receiving time of the wireless terminal; (3) calculating a value of difference between the current time and the latest heartbeat receiving time; (4) judging whether the value of difference is less than a set offline threshold value, if so, jumping to a step (5); otherwise, judging whether an IP address of the wireless terminal can realize ping passing through, if so, jumping to the step (5), otherwise, generating a wireless terminal offline warning information; (5) judging whether the wireless terminal is in anonline state before, if so, acquiring online information of the terminal judged last time, otherwise, generating a wireless terminal offline warning recovery information. The method provided by the invention realizes remote online monitoring for the electric power wireless terminal, guarantees real-time communication of electric power services and reduces operation and maintenance pressure of anelectric power LTE-1.8GHz wireless private network.

The invention discloses a multi-satellite multi-frequency band-based multi-architecture emergency guarantee system. The system is composed of three parts including a near-ground assimilation forecastcenter for realizing near-ground information assimilation, a monitoring subsystem for realizing field information analysis and supervision, and a multi-source data communication system for guaranteeing the rescue communication quality. Firstly, the near-ground assimilation forecast center takes a Beidou satellite group, a Tiantong satellite and a communication satellite as information sources, utilizes a WRF-EnSRF assimilation system to carry out assimilation on collected weather, geographical and disaster situation information, and realizes information publishing through an early warning information publishing network; secondly, the monitoring subsystem performs extraction analysis and fusion on positioning information, weather parameters, environment distribution and other data obtainedon site, and sets a bridge in the assimilation forecast center and the multi-source data communication system to realize real-time acquisition and supervision of the information; and finally, the multi-source data communication module realizes transmission of audio, video and text information by utilizing multiple communication means including a broadcast, a radar and a local area network.

The invention belongs to the technical field of network communication. The invention discloses a 1588 synchronization method, a 1588 synchronization system and a 1588 synchronization device for a high-speed TTE cascade network. The 1588 synchronization method comprises steps of enabling a port to calculate link delay; enabling a switching node to receive data frames, stamping receiving timestamps,analyzing the synchronous frame Sync and extracting the frame content; caching timestamp information, calculating time deviation, correcting a local clock, forwarding a synchronization frame Sync toa sending port, sending arbitration, sending analysis and caching a frame type, performing MAC sending processing, taking a sending timestamp, extracting the cached sending frame type, modifying a Sync frame correction domain, and finishing transparent transmission. According to the invention, the data frame type is analyzed at the data link layer and then MAC sending processing is carried out, sothat timestamp correction can be carried out rapidly when a synchronization frame is about to be transmitted to a high-speed network port; and meanwhile, the switching node is designed to adopt a transparent clock and common slave clock working mode, so that the universality and functional diversity of a synchronization scheme are improved.

The invention provides an intelligent electric vehicle regional architecture vehicle-mounted networked control system and a scheduling method, the system comprises a central computing unit and a regional control unit group which are connected through a network, and a software defined network (SDN) and time sensitive network (TSN) fusion scheduling logic framework is adopted. A global scheduling strategy command is generated in a centralized mode through an SDN controller and sent to a regional control unit, a regional scheduler in the regional control unit adopts a TSN mechanism, receives and executes a scheduling command from the SDN controller, manages all information in a single regional control unit, and sends the information to the SDN controller. Therefore, global scheduling management of communication is realized through upper and lower layer fusion of the SDN controller and the TSN mechanism, and the flexibility of system arrangement and the communication efficiency are improved. And a single sampling period of the system is decomposed into a plurality of sub-periods, and commands in the single sub-period are triggered by the same reference frame, so that the synchronism and the real-time performance of vehicle control are ensured.

The invention provides an equipment scheduling method and device, electronic equipment and a storage medium, which belong to the technical field of industrial automation. The method comprises the following steps: a, a preset route of returning to a preset point by highest priority equipment is determined, first to Nth nodes are marked sequentially based on a sequence in which the highest priorityequipment arrives at the nodes, and n is made to be 1; b, conflict equipment which arrives at the nth node later than the highest priority equipment in other priority equipment is determined based onthe preset route; c, a target node which the first piece of highest priority equipment does not pass through in the nodes before the conflict equipment arrives at the nth node is queried according tothe node arrival time reverse sequence; d, the conflict equipment is controlled to pass through the target node after the target node waits for the highest priority equipment to pass through the nearest node of the target node; and e, n is made to be n+1, the conflict equipment is eliminated, and steps of b to e are repeated. The conflict equipment waits for the highest priority equipment to passthrough the nearest node of the target node, so that the passing efficiency of the highest priority equipment is improved.

The embodiment of the invention provides a connection establishment method, a communication processing method and device and communication equipment. A first communication object sends a network connection request to a second communication object, and network connection with the second communication object is established; the second communication object forbids sending the network connection request to the first communication object, and then the first communication object sends a first communication message based on the network connection; the second communication object identifies an objectidentifier in the first communication message, puts the network connection into a connection pool, and stores a corresponding relationship between the object identifier and a storage address of the network connection in the connection pool; and the second communication object obtains the network connection from the connection pool based on the corresponding relationship, and can send the second communication message to the first communication object based on the network connection. According to the embodiment of the invention, the communication real-time performance is ensured, and the resource consumption is reduced.

The invention discloses a carrier channel data transmission distributed management system based on a medium-voltage line, and the system comprises a master management unit, a distributed management unit, slave nodes, a distribution network master station and a distribution network terminal, wherein the uplink of the master management unit is connected with the distribution network master station,and the downlink of the master management unit is connected with each slave node; the downlink of the distributed management unit is connected with each slave node, and the uplink of the distributed management unit is accessed to a network port in a previous-level system through a network cable to realize multistage distributed system architecture. The slave node is provided with two network portsand can be connected with two distribution network terminals at the same time, one network port can be used as a serial port for multiplexing and is used for connecting distribution network equipmentof two channel types, and the serial port can also be used for connecting a next-level distributed management unit. According to the invention, the original complex node relay relationship is simplified, the distributed management of each level of unit is realized, and the concurrent capability of the system is improved, so that the operation efficiency of the system is improved.

The invention provides a time slot allocation method and device and a readable storage medium. The time slot allocation method comprises the following steps: determining a first base station to whicha time slot is to be allocated; allocating a time slot to the first base station according to the current allocable time slot and a preset time slot allocation strategy; determining a second base station to which a time slot is to be allocated, wherein the second base station comprises a base station to which the time slot is not allocated in the first base station and a new base station to whichthe time slot is to be allocated except the first base station; determining an allocation base station for allocating a time slot to the second base station; and generating a time slot allocation command according to the time slot allocation strategy and the information of the second base station, and sending the time slot allocation command to the allocation base station, so that the allocation base station allocates a time slot to the second base station. According to the method, the time slot allocation efficiency is improved.

The invention discloses a communication method for master end equipment of a paired wireless communication device and the master end equipment. The communication method comprises the following steps: (11) switching a current working state from a sleep state to a wireless receiving-transmitting state after sleep time, and sending a handshake instruction to slave end equipment; (12) if a reply of the slave end equipment is received within preset time, implementing the step (13), otherwise implementing the step (14); (13) after ending communication with the slave end equipment, setting the sleep time as sleep time in an online state, switching the current working state from the wireless receiving-transmitting state to the sleep state, and implementing the step (11); and (14) setting the sleep time as sleep time in an offline state, switching the current working state from the wireless receiving-transmitting state to the sleep state, and implementing the step (11). Different sleep times are set according to different connection states, so that the communication instantaneity is ensured, and the power consumption of the master end equipment is further lowered effectively.

The invention provides an information synchronization system and method for a coupled-operating locomotive. The information synchronization system comprises dual mode wireless communication systems on all locomotives and linking-up stations in tunnels. Each dual mode wireless communication system comprises an xbee station and a locomotive station, and one locomotive device of the coupled-operating locomotive sends data to the xbee stations and the locomotive stations; during driving in a tunnel area, the xbee stations and the locomotive stations transmit data to the linking-up stations, and the linking-up stations send the data to the xbee stations and the locomotive stations of other locomotive bodies; and during driving in a non-tunnel area, one locomotive device of the coupled-operating locomotive transmits data needing to be transmitted from the xbee station and the locomotive station of one locomotive body to the xbee stations and the locomotive stations of the other locomotive bodies, and the xbee stations and the locomotive stations send information to the locomotive devices of the corresponding locomotive bodies. According to the information synchronization system and the method for the coupled-operating locomotive, a dual mode wireless communication method is adopted, and real-time datum communication and voice communication of the coupled-operating locomotive under the multi-tunnel complex road condition are achieved.

The invention provides an intelligent charging pile networking system adopting broadband power carriers, and relates to the technical field of communication of charging piles with video advertisement functions. The intelligent charging pile networking system comprises a distribution box and multiple groups of charging piles, the distribution box comprises a power distribution control unit and a main carrier module, the power distribution control unit and a power supply end of a main carrier module are separately connected to a power line, and a signal end of the power distribution control unit is connected to the power line through the main carrier module; the main carrier module of the electric carrier high speed communication technology is installed in the distribution box and is connected to all slave devices in the charging pile groups by power lines, the communication is realized by the power lines, and no additional wiring is required; and the main carrier module works as a connecting link between the preceding and the following in the whole network: uploading the information of a slave carrier module to the main carrier module through the power line so as to realize the communication between the main and slave carrier modules.

The invention belongs to the field of remote control and artificial intelligence and relates to an intelligent adjuvant therapy robot device for performing real-time social capability training for autism children. The device comprises a head movement driver (1), an arm movement driver (2), a device loader (3), a driving-driven wheel type chassis (4) and a casing module (7). A multi-joint combined driving mode is adopted, the collaborated driving capability of the robot for every movement joint is improved, the problem that time delay affects the interaction effect is solved, precise posture control of the robot in the random direction is achieved, a limb movement path planning function for automatically avoiding obstacles is achieved, and intelligent emotion interaction between a human and the robot and a safe and reliable family remote rehabilitation therapy model are achieved in various modes such as voice, images, touch and induction in the man-machine interactive process in response to emotion cognitive disorder which occurs universally in child patients.

The invention relates to the technical field of electric forklift battery pack equipment, in particular to a forklift battery pack parameter display system, comprising a power converter electrically connected with the power output terminal of the electric forklift battery pack. The conversion power output terminal of the power converter is electrically connected with a display device, a display controller, an alarm device and a keyboard respectively. The display controller is electrically connected with the display device, the alarm device, the keyboard and the CAN bus which is used for communicating with the power manager respectively. According to the forklift battery pack parameter display system disclosed by the invention, the voltage of the storage battery is converted to power supplyfor an electric device by arranging a power converter, and meanwhile, the system is dormant and awakened through the keyboard, so that the low power consumption characteristic of the whole system isensured. The communication between the display controller and the power manager is achieved through the CAN bus, and the communication protocol follows the CAN 2.0A or the CAN 2.0B, so as to ensure the real-time performance of the communication and the strong anti-electromagnetic interference characteristic.

The invention relates to a synchronous phasor calculation method based on DFT recursion of FPGA hardware. An FPGA is configured through a central processing unit (CPU) and controls an analog-digital (AD) converter to complete a sampling process under the 1 pulse per second signal (1PPS) synchronization, and the cycle DFT calculation and the recursion DFT calculation are utilized for eliminating accumulated errors of the recursion DFT calculation; and a complex phasor compensation algorithm is completed by the CPU. The FPGA and the CPU are matched to complete an acquisition calculation compensation process of synchronous phasors, and both the high-speed parallel computing capability of the FPGA and the flexible floating-point operation function of the CPU are used. The recursion DFP operation which is long in consumed time is completed by the FPGA, and the CPU loads are small, so that the communication response instantaneity of the CPU is guaranteed, and further, the communication reliability of a power management unit (PMU) is improved.

The invention discloses a vehicle network integration technology-based electric vehicle charging system and an implementation method thereof. The electric vehicle charging system comprises an electric vehicle network mobile computing terminal, which establishes a connection with an intelligent electric network via a power line carrier modulation and demodulation module, is connected with a cloud computing remote service platform, and uploads vehicle information of electric vehicles to the cloud computing remote service platform; the cloud computing remote service platform transmits charging information to positioning practicable charging station information and the electric vehicle network mobile computing terminal; electric vehicles are in information interaction via vehicle-mounted electric vehicle mobile computing terminals; and a microwave power transmission device is arranged in a charging station. The implementation of the invention is based on an electric vehicle technology integrating a vehicle intranet and a vehicle outer net; the vehicle intranet is large in information transmission capacity, is communicated with transport facilities via the wireless communication manner of a power line carrier; and the real-time performance of communication on the premises of multiple networks and larger data capacity is ensured.

The invention relates to the technical field of VR, especially to a wireless VR helmet based on a high-performance host. The wireless VR helmet comprises a helmet body, a wireless audio-video sending end, a wireless audio-video receiving end and a display screen, the wireless audio-video sending end comprises a coding unit and a wireless audio-video sending module, the wireless audio-video receiving end comprises a wireless audio-video receiving module and a decoding unit, and the decoding unit is connected with the display screen via an MIPI or LVDS interface. According to the invention, the VR helmet is no longer connected with the host in a wired manner due to use of a wireless communication technology, a user can walk freely in a larger space without limit of cables when using the wireless VR helmet, and the VR experience is improved; and graphs and computing resources in the host are fully utilized, signals of a signal source is decompressed in a compression-free or real-time compression manner, the communication instantaneity is ensured, and thus, dazzling caused by time delay is reduced.

The invention provides a material belt and film separation device of a chip mounter feeder and application of the material belt and film separation device, a braid is provided with a braid hole and an electronic element cavity, an electronic element is placed in the electronic element cavity, the electronic element cavity is provided with a fully-closed covering film, the material belt and film separation device comprises a shell, and an upper shell is arranged at the upper end of the shell; the upper shell is provided with a guide rail, a feeding port, a discharging port and a cutting tool, the upper end of the upper shell is provided with a material belt film turn-back guide plate, the rear end of the material belt film turn-back guide plate is provided with a material taking port, the material taking port is a through hole and is communicated with the guide rail, the upper shell is provided with a material film pressing plate, and the material film pressing plate is located at the upper end of the cutting tool; installation can be completed without a leading tape. The material changing time is shortened, the material belt can be replaced in only three seconds, and convenience and rapidness are achieved; a film drawing mechanism is omitted in the belt cutting mode, so that the feeder becomes the smallest feeder of the chip mounter in the world, and the feeder is small, exquisite, clean, low in cost and low in failure rate.

The invention discloses a communication real-time guaranteeing method of a vehicle-mounted CAN (Controller Area Network). The method comprises the following steps of: judging whether a maximum number S of messages which can be sent in a datum period is larger than the summation of a number S1 of period type messages required to be sent and a number S2 of reserved event type messages or not; if not, optimizing the quantity of the period type messages sent by electronic control units until a condition that the S1 is larger than the summation of the S1 and the S2 is met, and if so, distributing the period type messages to time slots of the datum period according to identifiers (ID) and reserving the event type messages to generate a message scheduling list; finally, selecting an electronic control unit as a time sequence datum node of the CAN, and broadcasting a starting message of the datum period via the datum period; and after all the electronic control units receive the starting message of the datum period, sending the period type messages according to the message scheduling list. The invention guarantees the use of the traditional CAN bus from time sequence and ensures that the messages sent by all the electronic control units can be sent out in real time, thus the communication real-time of the vehicle-mounted CAN is guaranteed. Meanwhile, because the vehicle-mounted CAN is implemented on the basis of the traditional CAN, the vehicle-mounted CAN is compatible with the traditional CAN and has low cost.

The invention discloses a rapid synchronous phasor correction method which involves an initialization module, a synchronous sampling module, a phasor computation module, a phasor correction module, a phasor FIFO buffer area read-write interface module and a CPU compensation module. The rapid synchronous phasor correction method has the advantages that through the capacity of high-speed parallel computing of an FPGA, the data synchronous sampling process, recursive DFT operation and a phasor filter algorithm are finished in the FPGA, so that a CPU is released from frequent sampling interruption and the heavy DFT operation process, the main task is focused on response to commands of a master station, and communication instantaneity of a PMU is guaranteed. Meanwhile, the phasor filter algorithm is optimized through a DA algorithm, more-digit multiplication of long bytes can be carried out synchronously, and the computational speed is greatly improved.

The invention discloses a damage control emergency command communication method and relates to the technical field of damage control systems. The method comprises the following steps: carrying out wireless communication connection between multiple multifunctional damage control helmets arranged in a damage control operation site and a damage control site command box, transmitting site pictures photographed by multiple multifunctional helmets in the damage control operation site to the damage control site command box in real time, wherein voice communication also can be carried out between thedamage control site command box and multiple multifunctional helmets, and carrying out communication connection between the damage control site command box and a command part command box located in acommand site by virtue of an optical fiber. Compared with the prior art, the scheme of the invention has the beneficial technical effects that real-time communication between command personnel and damage control team members can be guaranteed, the command personnel can conveniently, better and directly know condition of the damage control operation site and grasps the whole situation, and operation is promoted more efficiently.

The invention belongs to the technical field of network communication, and discloses a high-speed TTE cascaded network-oriented 1588 synchronization method, system, and device. The port calculates the link delay, the switching node receives the data frame, obtains the receiving time stamp, analyzes and extracts the synchronization frame Sync Frame content, cache timestamp information, calculate time offset, correct local clock, forward synchronization frame Sync to send port, send arbitration, send analysis and cache frame type, MAC send processing, get send timestamp, extract cached send frame type , to modify the Sync frame correction field to complete transparent transmission. The present invention adopts the method of analyzing the data frame type at the data link layer, and then performing MAC transmission processing, so that the time stamp can be quickly corrected when the synchronization frame is about to be transmitted to the high-speed network port; at the same time, the design switching node adopts a transparent clock plus a common The clock working mode improves the versatility and functional diversity of the synchronization scheme.

The invention discloses a method and a system for wireless networking communication. In the system, all node clocks keep synchronous with a coordinator clock, a communication cycle is set, the cycle is divided into a plurality of time slices, the coordinator assigns one monitoring time slice and a monitoring channel for relay nodes of each level, moreover, the coordinator can assign a plurality of time slices for the relay nodes in the first level, thus, power dissipation of the relay nodes in the first level is reduced further, each node only monitors wireless communication in own monitoring time slice and turns off wireless communication at other times; after the coordinator selects a path, a wireless communication data packet is sent within the time slice when the relay nodes of the next level start monitoring, the relay node of the next level receives the data packet and further forwards the data packet in the time slice when the relay nodes of the level after the next level start monitoring, and finally, the data packet arrives at the final node; after processing the data, the final node sends a return data packet within the time slice when the relay nodes of the previous level start monitoring again, the relay nodes of the level before the previous level forwards the uplink data packet within the time slice when the relay nodes of the previous level start monitoring again, finally, the data packet arrives at the coordinator, and thus one time of communication between the coordinator and the nodes is finished.