JPH05145577A - Terminal equipment - Google Patents

Abstract

PURPOSE:To reduce the packet transmission time by allowing a sender side terminal equipment to send a packet comprising compressed communication information and control information and allowing a receiver side terminal equipment to receive only a packet addressed to itself and decoding the communication information. CONSTITUTION:A CPU 9 stores communication data to a RAM 11 and stores control data to a ROM 10. Data from the RAM 11 are compressed by a compression section 3 and combined with data from the ROM 10 at a combined section 4 and a packet is sent to a transmission line 2 from a transmission section 5. A reception section 6 of other terminal equipment on the transmission line 2 receives a packet only when an address included in the control data is addressed to itself, a separating section 7 separater the data and sends the control data to the CPU 9 and the communication data to a decoding section 8. The decoding section 8 decodes the compressed data and sends the result to the CPU 9 and the CPU 9 applies decoding processing to the control data and the communication data. Thus, the packet transmission time is reduced and the transmission efficiency is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal device for transmitting / receiving packets on a data communication network.

[0002]

2. Description of the Related Art A data communication network such as a LAN is
As shown in FIG. 2, a large number of terminal devices 1 are connected by a transmission line 2 and data is transmitted and received in units of packets. FIG. 3 is a diagram showing the contents of a packet, which is composed of control data and communication data. The control data is F (flag) indicating the beginning and end of the packet, a header indicating the source address or serial number, and F used for error checking.
Including CS (frame check sequence) etc.,
Both are constructed according to a standardized format and have a constant bit length. On the other hand, the communication data indicates the contents of communication, the bit length is not constant, and is generally longer than the control data.

The packet having the above configuration is sent from the terminal device connected to the network to another terminal device via the transmission line 2. The terminal device receiving the packet compares the receiving source address contained in the header with its own address, recognizes that the address is addressed to itself, and takes in this packet.

[0004]

In order to improve the practicality of the data communication network, it is necessary to shorten the time required for packet transmission, but the transmission speed should be set higher than the limit determined by the transmission path. I can't.
Although the transmission time can be shortened by compressing and transmitting the entire packet, the content of the packet changes due to the compression. Therefore, the terminal device once restores all the packets flowing on the transmission path and returns them to the original state.
It must be judged whether or not it is addressed to itself from the receiving source address included in the control data. Therefore, it takes time to restore a packet that is not addressed to itself, and there is a problem that the transmission efficiency decreases.

Therefore, an object of the present invention is to shorten the time required for packet transmission and improve the transmission efficiency of a data communication network.

[0006]

A solution to the above problem is a terminal device for transmitting and receiving a packet composed of first data indicating control information and second data indicating communication contents.
A compression unit 3 that compresses the second data, a combining unit 4 that combines the first data and the compressed second data into a packet, and a transmission unit 5 that sends the packet onto the transmission path 2.
Then, it is determined from the first data of the packet on the transmission path 2 whether or not the packet is addressed to itself, the receiving unit 6 that receives only the packet addressed to itself, and the second unit compressed from the received packet. Separation unit 7 for separating data, and a compressed second
This is achieved by a terminal device characterized by including a restoration unit 8 that restores the data of 1.

[0007]

The packet transmitted from the transmitter 5 of the terminal device 1 according to the present invention onto the transmission path 2 has a shorter bit length than the original packet because the second data is compressed, and the packet is transmitted. It will reduce the time required for. Also,
Since the first data is transmitted without being compressed, the other terminal device determines whether or not the packet is the packet addressed to itself by the first data among the packets on the transmission path 2, It is possible to receive only the packet addressed to itself, and it is not necessary to restore all the packets on the transmission path 2.

[0008]

1 is a block diagram of a terminal device showing an embodiment of the present invention, in which 1 is a terminal device, 2 is a transmission line, 3 is a compression unit, 4 is a coupling unit, 5 is a transmission unit, and 6 is a reception unit. Section, 7 is a separating section, 8 is a restoring section, 9 is a CPU, 10 is a ROM, and 11 is a RAM.
Is.

First, the CPU 9 performs a process of creating communication data based on data input by an operator from a keyboard (not shown) and stores it in the RAM 11. Further, the ROM 10 stores in advance control data including a receiving source address and the like. Then, the contents of the RAM 11 are sent to the compression unit 3, and the compression unit 3 compresses the communication data. For data compression, the conventionally known MH method, MR method and the like can be used. Then, the combining unit 4 combines the control data sent from the ROM 10 and the compressed communication data sent from the compression unit 3 into a packet. The length of the control data is usually about several tens of bytes, whereas the communication data before compression generally has a length of about several Kbytes. Therefore, most of the packets before compression depend on the communication data. Occupied. Although the communication data varies depending on the nature of the communication data and the compression method, it is normally compressed to about 1/10, so the time required to transmit the packet after compression is reduced to about 1/10 of the conventional time. Will be done.

When a packet having the above-mentioned structure is transmitted from the transmission unit 5 onto the transmission line 2, the reception unit 6 of another terminal device includes the packet in the control data of the packet on the transmission line 2. It judges whether the source address matches its own address. If it does not match, it does not receive the packet. If it matches, it judges that it is the packet addressed to itself, and captures only this packet and separates it. Send to Part 7.

As described above, each terminal device does not need to capture all the packets flowing on the transmission line 2, and can select only the packet addressed to itself. Further, since the packet is compressed, the time taken to capture the packet is shortened. Therefore, the packet retention time on the transmission line 2 is shortened, and the number of packets per unit time that can be sent out on the transmission line 2 can be increased, so that the transmission efficiency of the transmission line 2 is improved as compared with the conventional case.

Then, the separating unit 7 separates the transmitted packet into control data and compressed communication data. Then, the control data is sent to the CPU 9, and the compressed communication data is sent to the decompression unit 8. The decompression unit 8 decompresses the compressed communication data into the original communication data and sends it to the CPU 9. The CPU 9 decodes the control data sent from the separation unit 7 and the communication data sent from the restoration unit 8.

[0013]

As described above, according to the present invention, the time required for packet transmission can be shortened even when the transmission rate is constant, which is useful for improving the transmission efficiency of the data communication network. is there.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention,

FIG. 2 is a diagram showing a configuration of a data communication network,

FIG. 3 is a diagram showing packet contents,

[Explanation of symbols]

1 terminal device, 7 separation unit, 2 transmission lines,
8 decompression section, 3 compression section,
9 CPU, 4 coupling parts, 10 RO
M, 5 transmitter, 11 RAM, 6 receiver,

Claims (1)

[Claims] 1. A terminal device for transmitting and receiving a packet comprising first data indicating control information and second data indicating communication contents, comprising: a compression unit (3) for compressing the second data. A combining unit (4) for combining the data of No. 1 and the compressed second data to form a packet, a transmitting unit (5) for transmitting the packet onto the transmission line (2), and a transmission line (2) It is judged from the first data of the above packet whether or not the packet is addressed to itself, and the receiving unit (6) that receives only the packet addressed to itself and the compressed second data from the received packet are separated. A terminal device, comprising: a separation unit (7) for performing decompression and a decompression unit (8) for decompressing the compressed second data.