JP2004096614A - Communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that the power consumption of high-speed radio equipment is larger than that of low-speed radio equipment, when a transmission rate is increased according to still picture data, in a communication system as a home network especially at homes. <P>SOLUTION: The system comprises a transmitter for transmitting a signal, having a data part 22 including information data 31 to be transmitted and a header part 21 to be transmitted prior to the data part 22, and a receiver for receiving the signal from the transmitter. The header part 21 has control information 26 for designating the modulation method and transmission rate A of the header part 21. After the transmitter transmits the header part 21 at a predetermined transmission rate A, the data part 22 is transmitted by a determined modulation method designated by the control information 26 and a transmission rate B. The receiver waits with a mode, in which the receiver can receive the predetermined modulation method and transmission rate A; and when receiving the header part 21, changes the receive mode to a mode in which the method and transmission rate are changed to the modulation method and transmission rate B designated by the control information 26. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a communication system for performing data communication using radio waves, and more particularly to a communication system that configures a home network at home.
[0002]
[Prior art]
In recent years, white goods such as air conditioners and refrigerators and security devices such as intrusion sensors and home controllers installed in the home are wirelessly connected, connected to mobile phones via the home controllers, and from outside the home. 2. Description of the Related Art A home network system has been developed which controls devices such as an air conditioner, and notifies home security personnel who are out of the house via a mobile phone.
[0003]
FIG. 3 shows the configuration of a conventional communication system, which will be described. In FIG. 3, reference numeral 1 denotes an antenna, 2 denotes a wireless transmission / reception unit, 3 denotes a modulation / demodulation unit, 4 denotes a control unit, and 5 denotes a transmission device. Reference numeral 6 denotes a receiving device which has the same configuration as the transmitting device 5. The modulation / demodulation means 3 corresponds to a binary FSK system with a transmission speed of 2400 bps. Devices such as an air conditioner (not shown) are connected to the control unit 4. When the state of a device connected to the control means 4 changes, a signal indicating the state change is input from the control means 4 to the modulation / demodulation means 3 and transmitted from the antenna 1 via the radio transmission / reception means 2 in a binary FSK modulation system of 2400 bps. A signal notifying the state change is emitted as a radio wave. The receiving means 6 receives the radio wave and transmits it to a home controller (not shown) connected to the receiving device 6.
[0004]
[Problems to be solved by the invention]
The data flowing through the home network system includes control data of white goods such as an air conditioner, and still image data of a surveillance camera as a security device. A transmission rate of the control data of several hundred bps is sufficient, but a transmission rate of at least several thousand to tens of thousands of bps is required as a transmission rate of the still image data. When the transmission speed of the entire network system is increased in accordance with the still image data, the current consumption of the wireless device is increased and the cost is increased as compared with a low-speed wireless device. Therefore, speeding up the wireless device is disadvantageous for a device that is low in speed and sufficient for data transmission such as control of white goods home appliances. In particular, for a battery-operated security device such as an intrusion sensor, speeding up the wireless device is a great disadvantage in terms of battery life. Therefore, there has been a problem that it has to be configured so that both low-speed data and high-speed data can flow on the network. There is a problem that the home controller must be configured to transmit and receive both low-speed data and high-speed data.
[0005]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a transmitting apparatus for transmitting a signal having a data section containing information data to be sent and a header section transmitted prior to the data section, and a receiving apparatus for receiving a signal from the transmitting apparatus The header section has control information for designating a modulation scheme and a transmission rate of a data section, and the transmitting device transmits the header section at a predetermined modulation scheme and a transmission rate A, and then transmits the data section. Is transmitted in the modulation scheme and the transmission rate B specified by the control information, and the receiving apparatus waits in a state where the predetermined modulation scheme and the transmission rate A can be received. It is configured to switch the reception state to the modulation method and transmission rate B specified by the information.
[0006]
According to the present invention, it is possible to provide a communication system in which data having different transmission speeds can flow over one network and data of any speed can be received.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
A communication system according to claim 1 of the present invention transmits a signal having a data section including information data to be transmitted and a header section transmitted prior to the data section, and receives a signal from the transmission apparatus. And a receiving device, wherein the header section has control information for specifying a modulation scheme and a transmission rate of a data section, and the transmitting apparatus transmits the header section with a predetermined modulation scheme and a transmission rate A, When the data section is transmitted with the modulation scheme and the transmission rate B specified by the control information, and the receiving apparatus waits in a state where the predetermined modulation scheme and the transmission rate A can be received, and receives the header section from the transmitting apparatus. The receiving state is switched to the modulation method and the transmission rate B specified by the control information.
[0008]
Further, it is possible to provide a communication system in which data having different transmission speeds can flow on one network and data of any speed can be received.
[0009]
In the communication system according to claim 2 of the present invention, the header section is a bit synchronization signal, a frame synchronization signal, control information for specifying a modulation scheme and a transmission rate of the data section, and a time related to a time until the data section is transmitted. Having information, the data part has a bit synchronization signal, a frame synchronization signal, and identification data for identifying a communication partner and information data, and after repeating the header part for a predetermined time or a predetermined number of times, transmitting the data part; It was done.
[0010]
Then, the communication partner can be notified of the transmission speed switching timing. The communication system according to claim 3, wherein a modulation method and transmission specified by the header section based on time information related to a time until a data section included in the header section repeatedly transmitted is transmitted. In this configuration, the time for switching the reception state to the speed B is determined.
[0011]
By knowing the transmission speed switching timing, data of any speed can be received more accurately.
[0012]
A communication device according to a fourth aspect of the present invention is a program for causing a computer to realize all or a part of the functions of the communication system according to any one of the first to third aspects.
[0013]
And since it is a program, a part or all of the communication system of the present invention can be easily realized using a microcomputer or the like. Further, by recording the program on a recording medium or distributing the program using a communication line, distribution and installation of the program can be simplified.
[0014]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
(Example 1)
FIG. 1 is a block diagram illustrating a communication system according to a first embodiment of the present invention. The same functional blocks as in the conventional example are assigned the same numbers as in FIG.
[0016]
In FIG. 1, 1 is an antenna, 2 is a radio transmitting / receiving means, 14 is a modulation / demodulation means, 10 is a switching means, and 11 is a control means. Reference numeral 12 denotes a transmission device. Reference numeral 13 denotes a receiving device which has the same configuration as the transmitting device 12. FIG. 2 shows a signal format transmitted from the transmission device 12. The operation of the present invention will be described with reference to FIG.
[0017]
The signal transmitted from the transmission device 12 is composed of a header section 21 for the transmission rate A and a data section 22 for the transmission rate B. In FIG. 2, the transmission speed A is 2400 bps and the transmission speed B is 9600 bps. In the modulation method, the header 21 is binary FSK, and the data 22 is GMSK. Further, the header unit 21 has one unit consisting of the bit synchronization signal 1 (23 in FIG. 2), the frame synchronization signal 1 (24), the identification code unit 1 (25), and the control information unit (26) as a basic unit ( 27), and the basic unit (27) is repeatedly transmitted a plurality of times. The bit synchronization signal 1 (23) is used to generate a sampling clock in the receiving device 13. The frame synchronization signal 1 (24) is for notifying the end of the bit synchronization signal 1 (23) and the beginning of the following identification code section 1 (25). Then, the destination to be sent is specified by the identification code unit 1 (25). The control information section (26) has information for designating the transmission speed and modulation scheme of the data section (22). Further, information indicating how many times the basic unit (27) is repeated is inserted into the control information section (26). The information indicating how many times the basic unit (27) is repeated may be the remaining number of times the basic unit is directly repeated, or the number of times the basic unit (27) has been repeated out of the number of times the basic unit is repeated. It may be something. Alternatively, the information may indicate the time (remaining time) itself corresponding to the remaining number of times the basic unit is repeated.
[0018]
The data section 22 includes a bit synchronization signal 2 (28 in FIG. 2), a frame synchronization signal 2 (29), an identification code section 2 (30), and data (31). The bit synchronization signal 2 (28) is used to generate a sampling clock in the receiving device 13. The frame synchronization signal 2 (29) is for notifying the end of the bit synchronization signal 2 (28) and the beginning of the identification code section 2 (30) that follows. Then, a destination to be sent is specified by the identification code unit 2 (30). The data 31 is, for example, still image data.
[0019]
After transmitting the header section (21), the transmission device 12 activates the switching means 10 according to the instruction of the control means 11 and switches the modulation method and transmission rate of the modulation / demodulation means 14 from 2400 bps binary FSK to 9600 bps GMSK.
[0020]
The receiving device 13 first waits at 2400 bps binary FSK, confirms that it is the device itself by the identification code portion 1 (25) of the header portion (21), decodes the control information portion, and decodes the data portion (22). Know the transmission speed and modulation method. Then, the demodulation method is switched to 9600 bps GMSK, and the data unit (22) waits. At this time, if information on how many times the basic unit (27) constituting the header section (21) included in the control information section (26) is repeated is acquired, the modulation scheme can be switched more reliably and the data section can be awaited. Can be.
[0021]
In the description of the present embodiment, the data portion is 9600 bps GMSK, but the data portion may be 4800 bps binary FSK or may be 20 kbps 8 value FSK.
[0022]
【The invention's effect】
As described above, the communication device of the present invention can provide a communication system in which data having different transmission speeds can flow over one network and can receive data of any speed.
[Brief description of the drawings]
FIG. 1 is a block diagram of a communication system according to an embodiment of the present invention. FIG. 2 is a signal format diagram of a communication system according to an embodiment of the present invention. FIG. 3 is a block diagram of a conventional communication system.
REFERENCE SIGNS LIST 1 antenna 2 wireless transmission / reception means 3 modulation / demodulation means 4 control means 5 transmission apparatus 6 reception apparatus 10 switching means 11 control means 12 transmission apparatus 13 reception apparatus

Claims (4)

A transmitting device for transmitting a signal having a data portion including information data to be transmitted and a header portion transmitted prior to the data portion, and a receiving device for receiving a signal from the transmitting device, wherein the header portion includes data Having control information specifying the modulation scheme and transmission rate of the section, the transmitting device transmits the header section at a predetermined modulation scheme and transmission rate A, and then the modulation scheme specified by the control information and the data section. The transmission is performed at the transmission rate B, and the receiving apparatus waits in a state where it can receive the predetermined modulation scheme and the transmission rate A. Upon receiving the header section from the transmission apparatus, the modulation scheme and the transmission rate specified by the control information are received. B. A communication system configured to switch the reception state to B. The header portion has a basic unit including a bit synchronization signal, a frame synchronization signal, control information for specifying a modulation scheme and a transmission rate of the data portion, and time information related to a time until the data portion is transmitted, 2. A transmitting apparatus comprising: a data section having a bit synchronization signal, a frame synchronization signal, identification data for identifying a communication partner, and information data, and transmitting the data section after repeating the basic unit a predetermined number of times. A communication system as described. A configuration for determining a time for switching a reception state to a modulation method and a transmission rate B specified by the header based on time information related to a time until a data included in a header transmitted repeatedly is transmitted. 3. The communication system according to claim 2, further comprising: A program for causing a computer to realize all or a part of the functions of the communication system according to claim 1.

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