TWI635396B - Data transmission system, a data receiving method and a data transmission method using two-stage memories to handle packet data - Google Patents

Abstract

A data transmission system, a data receiving method, and a data transmission method for processing packet data by using two-stage memory, by setting a buffer and a storage medium two-level memory on a client, when the client receives the group transmitted by the server When the packet is broadcast, the packet data in the multicast packet is temporarily stored in the buffer. When the complete data block is stored in the buffer, the data block is moved from the buffer to the storage medium and stored in the storage medium. When the data block in the data is not continuous, the technical means for notifying the server to resend the lost multicast packet can speed up the data receiving and processing speed of the client, and achieve the technical effect of completing the data transmission with less time and less bandwidth.

Description

Data transmission system, data receiving method, and data transmission method for processing packet data using two-stage memory

A data transmission system, a data receiving and data transmission method, in particular, a data transmission system, a data receiving method, and a data transmission method for processing packet data using two-stage memory.

The advantage of multicast (multicast, also known as multicast) technology is that the server can send data to multiple clients at the same time. Compared with the traditional unicast method used by TCP, the multicast technology takes up more. Less bandwidth. However, the shortcoming of the multicast technology is that packets may be lost during the data transmission process, especially when the data transmitted is relatively large, or when the client data is received or processed at a low speed.

In order to solve the problem that the packet transmission technology may lose the packet during the data transmission process, the client may request the server to resend the lost packet (refill) when it is determined that the packet is lost. However, once the server needs to request a resend packet, it means that the data transfer time will be extended. Once the packet is lost due to poor client data reception or processing speed, this will result in a significant increase in data transfer time.

In summary, it can be seen that in the prior art, there has been a long-standing problem that the multicast technology may prolong the data transmission time due to the loss of the client data due to the poor reception or processing speed of the client data, so it is necessary to propose an improved technology. Means to solve this problem.

In view of the prior art, there is a problem that the data transmission time is prolonged due to the loss of a large amount of packets due to poor reception or processing speed of the client data, and the present invention discloses a data transmission system and data for processing packet data using two-stage memory. Receiving method and data transmitting method, wherein:

The data transmission system for processing packet data using two-level memory disclosed in the present invention comprises at least a server and a client. The server further includes: a servo processing module, configured to divide the target data into a plurality of data blocks and divide each data block into packet data; and the servo transmission module is used to sequentially use at a certain frequency or speed. The multicast packet sends a data block, wherein the multicast packet includes the packet data, and is configured to receive the replenishment request transmitted by each client, merge the repeated replenishment request, and send the corresponding multicast packet according to the replenishment request. . The client further includes: a buffer; a client storage medium; a client transmission module, configured to request the server to join the multicast group, and configured to allocate a memory space in the buffer, receive the multicast packet, and multicast the group. The packet data in the packet is written into the corresponding location in the memory space; the client processing module is configured to move the data block from the buffer to the client when the packet data stored in the memory space has been formed into a complete data block. The storage medium is used to notify the server through the client transmission module when the data block is determined to be discontinuous according to the identification data of the data block stored in the customer storage medium, and according to the data block stored in the customer storage medium. The identification data determines that the customer storage medium has stored the complete target data and exits the multicast group through the customer transmission module.

The method for transmitting data disclosed in the present invention is applied to a server, and the server provides a client connection, and the steps include at least: dividing the target data into multiple data blocks, and dividing each data block into packet data; receiving the client The group sent by the terminal joins the request, and allows or denies the client to join the multicast group according to the number of clients and the number of times the target data is sent; repeat the following steps until the target data has been sent repeatedly for a certain number of times or the client exits the multicast group. Group: select the data block in the order of the data block in the target data at a certain frequency or speed; use the group broadcast packet to send the selected data block, the multicast packet contains the packet data; and the duplicate transmitted by the merge client The replenishment request; the corresponding multicast packet is sent according to the replenishment request.

The data receiving method for processing packet data by using the two-level memory disclosed in the present invention is applied to a client, the client includes a buffer and a client storage medium, and is connected to the server, and the steps include at least: requesting the joining group to the server Broadcast group; configure memory space in the buffer; receive the multicast packet transmitted by the server, and write the packet data in the multicast packet to the corresponding position in the memory space; determine the packet stored in the memory space When the data has formed a complete data block, the data block is moved from the buffer to the customer storage medium; when the data block is determined to be discontinuous according to the identification data of the data block stored in the customer storage medium, the transmission and the discontinuity are The data block corresponds to the replenishment request to the server; and according to the identification data of the data block stored in the customer storage medium, it is judged that the customer storage medium has stored the complete target data and exits the multicast group.

The system and method disclosed in the present invention are as above, and the difference from the prior art is that the present invention sets a buffer and a storage medium two-level memory on the client side, when the client receives the multicast packet transmitted by the server, First, the packet data in the multicast packet is temporarily stored in the buffer. When the complete data block is stored in the buffer, the data block is moved from the buffer to the storage medium and is in the data area in the storage medium. When the block is discontinuous, the notification server resends the lost multicast packet to solve the problems in the prior art, and can achieve the technical effect of completing the data transmission in a shorter time and less bandwidth.

The features and embodiments of the present invention will be described in detail below with reference to the drawings and embodiments, which are sufficient to enable those skilled in the art to fully understand the technical means to which the present invention solves the technical problems, and The achievable effects of the present invention.

The present invention is applied to a network environment in which a server uses a multicast technology for a large number of clients, wherein the present invention additionally provides a buffer in the client, so that the client receives the group sent by the server. When the packet is broadcast, the received multicast packet can be temporarily stored in the buffer, and then the complete data in the storage buffer is written into the storage medium.

Hereinafter, the operation of the system of the present invention will be described with reference to the components of the server of the present invention and the schematic diagram of the components of the client proposed by the present invention in the "Fig. 1". As shown in "Fig. 1" and "Fig. 2", the system of the present invention includes a server 100 and a client 200.

The server 100 is responsible for receiving the group join request transmitted by the client 200, and selecting whether to allow the client 200 to join the multicast group according to the current state of the server 100. In addition, the server 100 is also responsible for the target data through the multicast technology. The multicast packet is sent to the client 200 in the same multicast group. The server 100 further includes a servo storage medium 110, a servo processing module 120, and a servo transmission module 130.

The servo storage medium 110 is responsible for storing the target data. The target data stored in the servo storage medium 110 is usually a file with a large file size, but the invention is not limited thereto.

The servo processing module 120 is responsible for dividing the target data stored in the servo storage medium 110 into a plurality of data blocks with a predetermined block length (for example, 2 MB, but the invention is not limited thereto), and is predetermined. The data length (for example, 32 KB, but the invention is not limited thereto) divides each data block into one or more packet data. The data blocks generated by the segmentation of the servo processing module 120 have a corresponding order according to the position corresponding to the target data.

In some embodiments, the servo transmission module 130 may first compress the data block generated by the segmentation, and divide the compressed data block into packet data.

The servo transmission module 130 is responsible for receiving the group join request transmitted by the client 200, and selecting or allowing the client 200 to join the group according to the number of clients in the multicast group requested to join and/or the number of times the target data is sent. Broadcast group. For example, when the number of clients in the multicast group reaches a predetermined upper limit, for example, when the number of times the target data is sent reaches a predetermined number of times, the servo transmission module 130 may reject the client 200 to join the requested group. Broadcast group.

The servo transmission module 130 is also responsible for sequentially selecting the data blocks generated by the servo processing module 120 to segment the target data, and packaging the packet data of the currently selected data block into different multicast packets and transmitting them to the client. End 200. For example, the servo transmission module 130 may first encapsulate the packet data generated by the first data block segmentation into a multicast packet and send it to the client 200, and then sequentially process the packet data generated by the second data block segmentation. Encapsulated as a multicast packet and sent to the client 200, and so on.

The servo transmission module 130 may encapsulate a packet data into a multicast packet according to a certain frequency or speed and send the generated multicast packet to the client 200, or may package multiple packet data into different multicast packets at a time. The multicast packet is transmitted according to a certain frequency or speed, and the present invention is not particularly limited. Wherein, the certain frequency or speed may be a certain time interval (for example, every ten milliseconds) or a fixed time (for example, the zeroth millisecond and the 50th millisecond in every second), but the present invention does not To be limited, the above-mentioned certain frequency or speed may be a predetermined value of the system, or may be a set value set by the server 100 manager.

In general, the servo transmission module 130 may receive the group join request transmitted by the first client 200 after the server 100 is started and allow the client 200 to join the multicast group, that is, the client. After the connection with the server 100 is established, the multicast packet is sent to all the clients 200 participating in the multicast group according to the predetermined frequency or speed, and any subsequent client 200 is allowed or denied to join the multicast group. The frequency or speed at which the servo transmission module 130 sends the multicast packet to the multicast group is affected. However, the invention is not limited thereto. In some embodiments, the servo transmission module 130 may also stop transmitting the multicast packet when it is determined that there is no client 200 in the multicast group.

The servo transmission module 130 is also responsible for receiving the replenishment request transmitted by each client 200, and merging the repeated replenishment requests (that is, when different clients request to resend the same packet data, multiple requests for the same packet data will be requested). The packet request is treated as a replenishment request), and the corresponding multicast packet is sent to the client 200 that issues the replenishment request according to the received replenishment request.

In some embodiments, the servo transmission module 130 may discard a certain number of replenishment requests in the transmission order according to the requested multicast packet according to the received replenishment request when receiving the replenishment request. That is, when the number of packet data between the currently sent packet data and the requested packet data is more than a predetermined value, the servo transmission module 130 may discard the replenishment request of the requested packet data.

The client 200 is responsible for requesting the server 100 to join the multicast group, and is responsible for receiving the multicast packet sent by the server 100 through the multicast technology, so that the target data is obtained by the server 100. The client 200 includes a buffer 210, a client transmission module 220, a client processing module 230, and a client storage medium 240.

The buffer 210 is responsible for providing the client transmission module 220 to temporarily store the received packet data. The buffer 210 may use random access memory, flash memory, or other storage medium, and the present invention is not particularly limited. It is particularly worth mentioning that the buffer 210 is different from the buffer on the conventional network card, and is usually an additionally configured memory.

The client transmission module 220 is responsible for transmitting the group join request to the server 100, thereby requesting the server 100 to join the multicast group.

The client transfer module 220 is also responsible for configuring the memory space in the buffer 210, and the received packet data in the multicast packet is written into the corresponding location in the configured memory space. Generally, the multicast packet received by the client transmission module 220 is recorded with sufficient data for the client transmission module 220 to recognize the sequence of the received multicast packet (for example, the serial number in the multicast packet header or The number in the content of the multicast packet is not limited in the present invention, so that the client transmission module 220 can write the packet data in the multicast packet into the corresponding space in the memory space according to the order of the received group packet. position.

The client transmission module 220 can delete the packet data with the longest storage time when it is determined that the configured memory space is full, so as to store the newly received packet data.

In some embodiments, the client transmission module 220 may discard the multicast packet received within a predetermined time after joining the multicast group to avoid receiving the incomplete multicast packet and affecting the received data. Correctness.

The client processing module 230 is configured to determine that the complete data block is moved by the buffer 210 when the packet data stored in the memory space configured by the client transmission module 220 can form a complete one or more data blocks. To the customer storage medium 240, the completed data block is copied to the customer storage medium 240 for storage, and the package data copied to the customer storage medium 240 is deleted from the buffer 210.

The client processing module 230 is also responsible for determining, according to the identification data of the data block stored in the client storage medium 240, that the data block stored in the client storage medium 240 is discontinuous, and notifying the server 100 through the client transmission module 220. When it is determined that the client storage medium 240 has stored the complete target data according to the identification data of the data block stored in the client storage medium 240, the client transmission module 220 is notified to exit the multicast group. Generally, the identification data of the above data block may be arbitrarily arranged by any number of characters or numbers, and the present invention is not particularly limited, but the identification data of different data blocks is not repeated.

Next, an operation system and method of the present invention will be described with reference to an embodiment. Referring to FIG. 3, a flowchart of a data transmission method according to the present invention and a "fourth diagram" using the second-order memory of the present invention. A flow chart of a method for receiving data for processing packet data. This embodiment assumes that the present invention is applied to a production line, but the present invention is not limited thereto.

After the server 100 is started, the servo processing module 120 of the server 100 can read the target data from the servo storage medium 110 of the server 100, divide the target data into multiple data blocks, and divide each data block. Split into packet data (step 305).

Thereafter, when the client 200 moves on the production line, the client transmission module 220 of the client 200 can connect with the server 100 and transmit a group join request to the server 100, thereby requesting the server 100 to join the multicast group ( Step 402). In this embodiment, it is assumed that the client transmission module 220 can connect to the server 100 through the wireless network and transmit the group join request to the server 100 through the wireless network technology.

After the servo transmission module 130 receives the group join request transmitted by the client 200, the servo transmission module 130 may select the permission according to the number of clients currently joined to the same multicast group and/or the current number of transmissions of the target data. Or the client 200 is denied to join the requested multicast group (step 320). In this embodiment, it is assumed that the number of clients in the multicast group that the client 200 requests to join does not reach the upper limit value of 200, and the current number of transmissions of the target data has not reached the predetermined number of times five times. Thus, the servo transmission Module 130 may choose to allow client 200 to join the requested multicast group. If the client group 200 requests to join the multicast group has 200 other clients join, or the target data is currently sent 5 times (last time), the servo transmission module 130 may choose to reject the client 200. Join the requested multicast group. In this way, the client 200 needs to wait for the other client 200 to leave the requested multicast group, or wait for the servo transmission module 130 to restart sending the target data before the servo transmission module 130 can Select to allow client 200 to join the multicast group.

When any client 200 is allowed to join the multicast group, the servo transmission module 130 may first select the data block in the order of the data blocks generated by the segmentation in the target file at a certain frequency or speed (step 330). And then, the packet data in the selected data block is sequentially encapsulated into a multicast packet, and the packaged multicast packet is sent to the client 200 (step 340). In this embodiment, it is assumed that after the segmentation of the data block is generated, the servo transmission module 130 may first compress the generated data block, and then divide the compressed data block into packet data, and may be scheduled every predetermined time. The multicast packet is sent to all clients 200 in the multicast group at intervals.

After the client 200 joins the multicast group, the client transfer module 220 of the client 200 can configure the memory space in the buffer 210 of the client 200 (step 406). In this embodiment, it is assumed that the memory space configured by the client transmission module 220 is 75% of the remaining space in the buffer 210.

Then, when the client transmission module 220 receives the multicast packet transmitted by the servo transmission module 130, the packet data in the received multicast packet can be written into a corresponding location in the memory space (step 410). In this embodiment, in order for the client 200 to ensure the correctness of the received data, after the client 200 joins the multicast group, the client transmission module 220 may discard all the multicast packets received within the predetermined time. . In addition, when the client transmission module 220 receives the multicast packet transmitted by the servo transmission module 130, if the memory space is full, the client transmission module 220 may delete the packet data with the longest storage time and then write Enter the received packet data.

In addition, after the client 200 joins the multicast group, the client processing module 230 of the client 200 can also determine whether the packet data written in the buffer 210 by the client transmission module 220 has formed a complete data block. (Step 420). If yes, the client processing module 230 can move the packet data that has formed the complete data block together with the buffer 210 to the client storage medium 240 of the client 200 (step 430); if not, the client processing module 230 can Waiting for the packet data written in the buffer 210 by the client transmission module 220 to form a complete data block.

After the client processing module 230 moves the packet data constituting the complete data block from the buffer 210 to the client storage medium 240 of the client 200, the client processing module 230 can further determine the data block stored in the client storage medium 240. Whether it is continuous (step 440). If the data block in the client storage medium 240 is not continuous, the client transmission module 220 may transmit a replenishment request corresponding to the discontinuous data block to the server 100 (step 450), and continue to receive the transmission by the server 100. The multicast packet is encapsulated, and the packet data in the multicast packet is written into the memory space (step 410). For example, when the data block stored in the client storage medium 240 is the first and third data blocks and there is no second data block, the client processing module 230 can determine the data stored in the client storage medium 240. The block is discontinuous, and the client transmission module 220 is notified to check the packet data of the second data block in the buffer 210, and encapsulate the identification data of the packet data of the second data block that has not been received as a phase. The corresponding replenishment request is transmitted to the server 100 for the replenishment request generated.

When the servo transmission module 130 receives the replenishment request transmitted by the client 200, the servo transmission module 130 may first record the identification data of the packet data requested to be resent, and send a complete data block to the client. After the terminal 200, the same replenishment request transmitted by the different clients 200 is merged (step 350), and the corresponding multicast packet is sent to the client 200 according to the merged replenishment request (step 370). In this embodiment, if two clients 200 request to resend the packet data of the identification data 208, and one client 200 requests to resend the packet data of the identification data 413, the servo transmission module 130 may The replenishment request for resending the identification data to the packet data of 208 is merged into one, so that the servo transmission module 130 can transmit only one multicast packet with the package identification data of 208 and a package identification data of 413. The multicast packet of the data is sent to the client 200.

If the client processing module 230 determines that the data blocks stored in the client storage medium 240 are continuous, the client processing module 230 can determine again whether all the data blocks have been stored in the client storage medium 240, that is, the client storage media is determined. Whether the complete target data has been stored in step 240 (step 460), if not, the client transmission module 220 continues to receive the multicast packet transmitted by the server 100, and the packet data in the multicast packet is written into the memory space. (Step 410); if so, the client processing module 230 may decide to have the client 200 exit the multicast group, so that the client 200 can continue to move on the production line, and the client transmission module 220 can transmit the group exit message to The server 100 causes the client 200 to exit the joined multicast group (step 470).

In addition, after the servo transmission module 130 sends the corresponding multicast packet to the client 200 according to the received replenishment request (step 370), the servo transmission module 130 can determine whether the target data has been sent a certain number of times or the client. Whether end 200 has exited the joined multicast group (step 380). If yes, the server 100 can end the invention; if not, that is, the target data has not been sent a certain number of times (such as 5 times) or the client 200 is still in the multicast group, the servo transmission module 130 can continue to be certain The frequency or speed is sequentially selected in the order of the data blocks generated by the segmentation in the target file (step 330), and then the packet data in the selected data block is sequentially encapsulated into a multicast packet. And sending the encapsulated multicast packet to the client 200 (step 340).

In summary, it can be seen that the difference between the present invention and the prior art is that there is a client setting buffer and a storage medium two-level memory. When the client receives the multicast packet transmitted by the server, the multicast packet is firstly packetized. The packet data in the buffer is temporarily stored in the buffer. When the complete data block is stored in the buffer, the data block is moved from the buffer to the storage medium, and when the data block in the storage medium is discontinuous, The technical means for notifying the server to resend the lost multicast packet, by using a technical means, can solve the problem that the data transmission time may be prolonged due to the loss of a large amount of packets due to poor reception or processing speed of the client data in the transmission process of the prior art. The problem, in turn, achieves the technical effect of completing data transmission with less time and less bandwidth.

In the above embodiment, when the servo transmission module 130 receives the replenishment request transmitted by the client 200, the servo transmission module 130 may also discard the transmission order of the multicast packet requested according to the received replenishment request. A certain number of replenishment requests before. In this embodiment, it is assumed that the identification data of the currently sent packet data is 315, and the identification data of the requested packet data is 228, because the order difference between the requested packet data and the currently sent packet data is 87, When a sequence difference is more than a predetermined value of 50, the servo transmission module 130 may discard the replenishment request of the requested packet data, and record the identification data of the requested packet data that has not been discarded, that is, select not to resend the transmission sequence. A certain amount of packet information before. In other words, when the client 200 requests to resend a certain amount of packet data in the transmission order, the client 200 cannot immediately receive the packet data requested to be retransmitted, but needs to wait for the servo transmission module 130. When the packet data is resent to the client 200 again in the order of the first data block, the second data block, ..., the packet data requested to be resent can be received.

Furthermore, the data receiving method and the data transmitting method for processing the packet data using the two-step memory of the present invention can be implemented in a combination of hardware, software or hardware and software, or can be implemented in a centralized manner in a computer system or This is achieved by a distributed approach in which different components are interspersed among several interconnected computer systems.

While the embodiments of the present invention have been described above, the above description is not intended to limit the scope of the invention. Any modification of the form and details of the practice of the present invention, which is a matter of ordinary skill in the art to which the present invention pertains, is a patent protection of the present invention. range. The scope of the invention is to be determined by the scope of the appended claims.

100 server 110 servo storage medium 120 servo processing module 130 servo transmission module 200 client 210 buffer 220 client transmission module 230 client processing module 240 client storage media step 305 split the target data into multiple data blocks, And dividing the data block into the packet data step 320, receiving the group join request transmitted by the client, and allowing or denying the client to join the multicast group step 330 according to the number of the client and the number of times the target data is sent, at a certain frequency or The speed selects the data block in the order of the data block in the target data. Step 340: Send the selected data block using the multicast packet, the multicast packet includes the packet data, step 350, and the repeated replenishment request step 370 transmitted by the merge client Sending the corresponding multicast packet step 380 according to the replenishment request, whether the target data is Repeat sending a certain number of times or whether the client exits the multicast group step 402, requesting the server to join the multicast group step 406, configuring the memory space in the buffer, step 410, receiving the multicast packet transmitted by the server, and The packet data in the broadcast packet is written into the corresponding location in the memory space. Step 420 Whether the packet data has formed a complete data block. Step 430: Move the data block from the buffer to the client storage medium. Step 440 Whether the data block continues in step 450 Transmitting a replenishment request corresponding to the discontinuous data block to the server, step 460, whether the complete target data has been stored, step 470, exiting the multicast group

Figure 1 is a schematic diagram of the components of the server of the present invention. Figure 2 is a schematic diagram of the components of the client proposed by the present invention. Figure 3 is a flow chart of the data transmission method proposed by the present invention. FIG. 4 is a flow chart of a method for receiving data for processing packet data using two-level memory according to the present invention.

Claims (7)

A data transmission system for processing packet data using two-stage memory, the data transmission system comprising: at least one server, further comprising: a servo processing module for dividing a target data into a plurality of data blocks and dividing Each of the data blocks is at least one package data; and a servo transmission module is configured to send, by using at least one group of broadcast packets, a data block in sequence according to a certain frequency or speed, wherein each of the group broadcast packets comprises one Packet data, and a request for receiving each replenishment request, merging and repeating each of the replenishment requests, and requesting, according to each of the replenishment requests, a certain number of the replenishment requests, and according to the Some of the replenishment requests are sent to the corresponding group of broadcast packets; and a client, further comprising: a buffer; a client storage medium; and a client transmission module for requesting the server to join the group of broadcast groups And configuring a memory space in the buffer, receiving at least one group of broadcast packets, and writing the packet data in each of the group broadcast packets into the memory space. And a client processing module, configured to: when the packet data stored in the memory space has formed at least one data block, move the data block from the buffer to the customer storage medium And determining, by the identification data of the data blocks stored in the customer storage medium, that the data blocks are discontinuous, notifying the server through the client transmission module, and according to the customer storage medium Identification of the stored data blocks The data is determined to notify the customer that the transmission module has exited the multicast group when the client storage medium has stored the complete target data. The data transmission system for processing packet data by using a two-level memory as described in claim 1, wherein the customer data transmission module is further configured to discard the plurality of data received after joining the group broadcast group within a predetermined time period. Group broadcast package. The data transmission system for processing packet data using the second-order memory as described in claim 1, wherein the servo transmission module is further configured to use the number of clients in the multicast group and/or the target data. Sends the number of choices to allow or deny the client to join the multicast group. A data transmission method for processing packet data using two-level memory, the data transmission method comprising at least the following steps: a server divides a target data into a plurality of data blocks, and divides each of the data blocks into at least one package data. At least one client transmits a group join request to the server; the server allows or denies the client to join the group based on the number of clients currently joined to the group of broadcast groups and the number of times the target data is sent a group; after the client joins the group, configure a memory space in a buffer; and repeat the following steps until the server has repeatedly sent the target data for a certain number of times or in the multicast group The client exits the multicast group: the server selects a data block in the order of each data block in the target data at a certain frequency or speed; the server sends the selected one using at least one group of broadcast packets. a data block to the at least one client, each of the group broadcast packets including a packet data; Receiving, by the at least one client, the at least one group of the broadcast packets, and writing the packet data in the at least one group of the broadcast packets to corresponding locations in the memory space; the at least one client determining the packets stored in the memory space When the data has formed at least one data block, the data block is moved by the buffer to a client storage medium; the client judges according to the identification data of the data blocks stored in the client storage medium. The client storage medium exits the multicast group when the complete target data is stored; the client determines whether the data blocks are discontinuous according to the identification data of the data blocks stored in the customer storage medium, and transmits or not The plurality of data blocks corresponding to the replenishment request are consecutively sent to the server; the server merges the repeated replenishment request transmitted by the at least one client; the server discards a certain number of the transmission order Replenishing the request; and the server sends the corresponding group of the broadcast package to the at least one client according to the replenishment request. The data transmission method for processing packet data by using two-level memory according to claim 4, wherein the step of transmitting the data block by using at least one group of broadcast packets in sequence at a certain frequency or speed further comprises compressing the data. The steps of the block. The data transmission method for processing packet data by using a second-order memory according to claim 4, wherein the at least one client writes the packet data in the at least one group of the broadcast packets to a corresponding position in the memory space. Before the step, the method further includes the step of discarding the group broadcast packet received within the predetermined time. The data transmission method for processing packet data by using a second-order memory according to claim 4, wherein the at least one client writes the packet data in the at least one group of the broadcast packets to a corresponding position in the memory space. The step further includes the step of deleting at least one of the storage time of the packet data when the at least one client determines that the memory space is full.