JPH0787224A - Data transmitter for multimedia inputting data and system for input of multimedia - Google Patents

Abstract

PURPOSE:To provide a multimedia input data transmitter and a multimedia input system for OA data to quickly perform the input and encoding of data when it is generated. CONSTITUTION:The multimedia input system 1 is constituted of a portable multimedia input transmitter 10 and a center device 50, and the portable multimedia input transmitter 10 is constituted of portable input unit groups 20-1, ... 20-i used selectively corresponding to inputted OA data of every kind of mode, and a portable radio terminal station device 30 which connects the data from the portable input unit groups to a radio terminal station and transmits them by an SS communication system. The center device 50 receives SS transmission data from the portable radio terminal station device 30, and outputs by demodulating it to an output device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable multimedia input data transmitting apparatus for transmitting input data wirelessly and a multimedia input system using the apparatus.

[0002]

2. Description of the Related Art In recent years, various OA devices such as word processors, facsimiles, and OCRs (optical character reading devices) have been developed and commercialized with the progress of OA (Office Autmation), and are still being made. In the case of OA equipment, transmission / reception of image data (image data) such as document data input from a keyboard or facsimile as a form of data as information is conventionally known.

[0003]

However, the data transmission / reception caused by the OA at the present time is performed and processed by completely independent routes for each data form, and various data are transmitted or processed in a unified format. In addition, there is an inconvenience that it is difficult in many cases to input data in real time at the time of actual data generation.

For example, in the case where a utterance during a conference is recorded as a minutes and printed out by a word processor and distributed to attending members, after inputting from a keyboard to an OA device such as a word processor based on a memo of the utterance contents after the conference. It is usually edited, output and distributed. in this way,
In the conventional OA data input method, an input operation by a person (operator) is involved between the actual data generation and the data editing / output, so that the actual OA data input method may vary depending on the operator's proficiency level and work schedule. There is a problem that it takes time to edit and output the data after the data is generated. For example, the distribution of the minutes may be delayed, or the minutes may not be distributed in some cases. .

The present invention has been made in view of the above inconveniences and problems, and a multimedia input data transmitting apparatus and a multimedia input system for OA data capable of promptly inputting and encoding data when data is generated. The purpose is to provide.

[0006]

In order to achieve the above object, the present invention uses a group of terminal units corresponding to each data form in order to quickly transmit and process the inputted OA data to a center device. , The data from these terminal units is connected to a wireless terminal station and transmitted by the SS (Spred Spectrum) communication method. As a concrete configuration of the invention, a multimedia input data transmitting apparatus according to the first invention includes a plurality of input apparatuses having different input data forms,
And a wireless terminal station device that connects the plurality of input devices, selectively inputs output data from the plurality of input devices, modulates the data as a spread spectrum signal, and performs spread spectrum transmission.

A multimedia input data transmitting device according to a second aspect of the present invention is an input device capable of inputting data in a predetermined input form, and a conversion circuit for performing a predetermined conversion on data from the plurality of input devices to obtain a converted signal. And a multimedia input data transmitting apparatus that modulates the converted signal as a spread spectrum signal and performs spread spectrum transmission.

A third aspect of the present invention is the multimedia input data transmitting apparatus according to the first aspect, wherein the wireless terminal device determines data type discriminating means for discriminating the form of the input data and the input data. Coding means for coding and obtaining an input data signal, frequency modulation means for frequency-modulating the input data signal with a given frequency to obtain a modulated signal, and spread spectrum of the modulated signal with a given pseudo-noise code, and a spread spectrum signal And a transmission means for transmitting a spread spectrum signal.

A fourth invention is a multimedia input data transmitting apparatus according to the first or second invention, and a center apparatus for receiving a spread spectrum signal from the multimedia input data transmitting apparatus and demodulating and outputting output data. When,
It is characterized by consisting of.

In a fifth aspect of the invention, the center device used in the multimedia input system according to the fourth aspect of the invention receives a transmission signal from an arbitrary multimedia input data transmission device, and from the transmission signal a specific multimedia input data is received. A signal extracting means for extracting a spread spectrum signal from the transmitting device, and a modulated signal extracting means for correlating the extracted spread spectrum signal with a pseudo signal provided by a specific multimedia input data transmitting device and extracting a modulated signal. A demodulation means for demodulating the modulated signal to obtain an input data signal, and output devices respectively connected corresponding to the input devices for outputting the input data having different forms,
Output device selecting means for discriminating the type of the input data and selecting an output device for outputting the input data from the connected output devices.

A sixth invention is characterized in that the center device according to the fifth invention further comprises a transmission output terminal for transmitting the output from the demodulation means.

[0012]

With the above-described structure, the multimedia input data transmitting apparatus according to the first aspect of the invention selectively outputs output data from a plurality of input devices having different input data forms, and modulates the spread data as a spread spectrum signal. Spread transmission. A multimedia input data transmission device according to a first aspect of the present invention selectively connects a plurality of input devices having different input data forms, inputs output data from the connected input devices, and modulates the spread data as a spread spectrum signal to spread the spectrum. Send. A third aspect of the present invention is the multimedia input data transmitting apparatus according to the first aspect, wherein the wireless terminal device determines the data type for discriminating the form of the input data by the data type discriminating means and the input data by the encoding means. The encoded input data signal is frequency-modulated by the frequency modulating means with a given frequency to obtain a modulated signal. Then, the spread spectrum means spreads the modulated signal with a given pseudo-noise code to obtain a spread spectrum signal, and the transmitting means transmits the spread spectrum signal by spread spectrum.

In a fourth aspect of the present invention, the center device receives the spread spectrum signal from the first or second multimedia input data transmitting device, demodulates the output data and outputs the demodulated data.

In a fifth aspect of the invention, the center device used in the multimedia input system according to the fourth aspect of the invention receives a transmission signal from an arbitrary multimedia input data transmission device, and the signal extraction means identifies the transmission signal from the transmission signal. The spread spectrum signal from the multimedia input data transmitter is extracted, and the modulated signal is extracted by correlating the spread spectrum signal extracted by the modulation signal extraction means with the pseudo signal given by the specific multimedia input data transmitter. To do. Then, the demodulation means demodulates the modulated signal to obtain the input data signal, the output device selection means discriminates the type of the input data, and the output device for outputting the input data is selected from the connected output devices. , The data is output by the selected output means.

According to a sixth aspect of the present invention, in the center device according to the fifth aspect, the output from the demodulating means is transmitted to another device through the transmission output terminal.

[0016]

1 is a block diagram showing the basic configuration of a multimedia input system according to the first invention. Figure 1
In the above, the multimedia input system 1 comprises a portable multimedia input transmission device 10 and a center device 50, and the portable multimedia input transmission device 10 selectively uses it corresponding to input OA data of each form. The portable input unit group 20-1, ..., 20-i and those portable input units are selectively connected, the data from the portable input unit group 20 is encoded, modulated into SS transmission data, and SS ( Spread Spectrum)
It is composed of a portable wireless terminal device 30 that transmits by a communication method. Then, the center device 50 receives the SS transmission data from the portable radio terminal device 30 and demodulates it. Portable input unit group 20, portable wireless terminal device 3
0 and the center device 50 are specifically configured as shown in FIGS.
, And an application example is shown in FIG. These configurations and functions will be described later.

FIG. 2 is a block diagram showing a configuration example of a portable input unit group 20 which constitutes the portable multimedia input transmission apparatus 10 of FIG. Portable input unit group 2
0 is composed of a plurality of sets of an input device corresponding to the data form of the input data, a data conversion circuit for encoding the input data, and an output terminal, and the portable radio terminal station device 30 and these terminal unit groups selectively, Alternatively, they are connected in parallel. Which terminal unit is connected to the portable wireless terminal device 30 and which terminal unit uses data is selected by the user according to the form of the input data (see FIG. 3; described later). .

In FIG. 2, image input data, voice input data and characters (numerical value) are typical input data forms.
The case of input data is shown as an example. CCD input device
(Charge Coupled Device) and the like, image input device 21-1, voice input device 2 such as a microphone
1-2 is a character numerical value input device 21-3 by a keyboard, and the data conversion circuits 22-1 and 22-2 digitally input data from the image input device 21-1 and the voice input device 21-2 such as a microphone. Turn into. Here, for example, in the case of voice input data, the data conversion circuit 22-2 performs the conventionally known sampling, quantization, and encoding processes,
If necessary, compression processing is also performed to make digital data.
Further, the image input data can be easily digitized by the data conversion circuit 22-1 by a well-known method. Data conversion circuits 22-1, 22-2 and keyboard 20-3
From the output terminals 23-1, 2 respectively.
3-2 and 23-3 electrically connect to the portable wireless terminal device 30.

FIG. 3 is a block diagram showing a configuration example of the portable radio terminal station device 30. The portable radio terminal station device 30 has input terminals 31-1 to 31-i, an encoding circuit 32, and a multiplier 3.
3, 34, antenna 35, RF (radio frequency) oscillator 3
6, a PNG (pseudo noise code (code) generator) 37, a control circuit 38, a data selection circuit 39, a transmission frequency setting circuit 40, a PN code setting circuit 41, an operation panel 42, and a call unit 43. Input terminal 31-
1 to 31-i or the selection circuit 39 corresponds to the data type discrimination means, the encoding circuit 32 corresponds to the encoding means, the RF oscillator 36 and the multiplier 33 are the frequency modulation means, and the PNG 37 and the multiplier 34 are the spread spectrum means. Make up.

The input terminals 31-1, 31-2, 31-3 are output terminals 23-1, 23- of the portable terminal unit group 20.
2, 23-3 corresponding to the connection, the operation panel 4 described later
Digital data from the output terminal of the portable terminal unit which is selectively controlled by the control device 38 based on the input data type from 2 (menu selection, designation code by the selection key or code input from the keyboard) and corresponds to the form of the input data. Is input to the portable wireless terminal device 30. In this case, the portable wireless terminal device 3 is connected to the input terminal without inputting the data type set from the operation panel.
The data type may be automatically set when the 0 output terminal is connected. The input data is transmitted by the portable radio terminal device 30 as an SS (spread spectrum) signal to the center device (50, which will be described later) via the antenna 35. The user operates the operation panel in advance to set the frequency for transmission. And the type of PN code is selected (described later).

Based on the three types of operation information (type of input data, transmission frequency and type of PN code) selected as described above, the encoding circuit 32 has the input terminals 31-1,
The digital data input via either 31-2 or 31-3 is encoded, the RF oscillator 36 generates a selected frequency, and the PNG 37 generates a selected PN code.
The multiplier 34 outputs the encoded data from the encoding circuit 32 to RF.
Modulation is performed at the selected frequency generated by the oscillator 36 (FM modulation in this embodiment is not limited to this), and the multiplier 3
4 further generated the modulation data by the PNG 37 P
The signal is modulated with an N code and SS-transmitted as an SS signal from the antenna 35 to the center device 50.

The portable radio terminal station device 30 and the center device 50 are provided with a communication unit 43 so that the respective operators can communicate with each other by voice so that not only data but also voice communication can be performed. For a call between the portable radio terminal device 30 and the center device 50, a telephone device using a minute current that has been conventionally used may be used. The data selection circuit 39 sends the input data selection information input from the operation panel 42 as digital data to the control circuit 38, and the transmission frequency setting circuit 40 outputs the frequency setting information input from the operation panel 42 as digital data to the control circuit 38. To the operation panel 42.
The PN code setting information input from is sent to the control circuit 38 as digital data.

Further, the operation information (the type of input data, the transmission frequency and the type of the PN code) can be exchanged with the center device 50 side between the operators using the call unit, but via the call unit. It may be configured to transmit. The transmission frequency setting circuit 40 and P
The N code setting circuit 41 can be omitted as described later (see the description of FIG. 4). In this case, the data type information may be SS-transmitted prior to the SS transmission of the input data. The control circuit 38 receives the above-mentioned three types of operation data selected, selects the input terminal, and the RF oscillator 3
6 sets the transmission frequency, sets the PN code for the PN code oscillation circuit, and controls the entire portable wireless terminal station device 30.

FIG. 4 is a flow chart showing the basic control procedure of the portable multimedia input transmitting apparatus 10 including the portable terminal unit group 20 and the portable wireless terminal station apparatus 30 of FIGS. The above procedure will be described below with reference to this flowchart. [S1] Set of data type The user inputs information on which form the input data is from the operation panel 42 of the portable wireless terminal device 30 according to the form of the input data. Input is the operation panel 4
The operation is performed using the function keys provided on the keyboard 2 or an ordinary keyboard (neither is shown). When the data type is set to be automatically set when the output terminal of the portable radio terminal station device 30 is connected to the input terminal, in this step the portable radio terminal station device is set to the input terminal. When the 30 output terminals are connected, the data type is set.

[S2] Frequency setting After setting the data type, the assigned frequency of the wireless terminal device 30 is set from the function key or the keyboard in the same manner as in the case of setting the data type. If the assigned frequency of the wireless terminal device 30 is set in the wireless terminal device in advance, this operation step can be omitted.

[S3] PN code setting A PN code is set according to the type of input data. PN
The code is set in the same manner as the case of setting the data type described above. If the assigned frequency of the wireless terminal device 30 is set on the device side in advance and the PN code is set at the same time when the data type is set in step S1, this operation step is omitted. it can.

[S4] Data input waiting loop The user inputs data from the input device of the terminal unit according to the form of the input data, and the wireless terminal station device 30 side determines whether or not data has been input. The operation is always performed (when the switch of the device is ON), the control is moved to step S5 when the data is input, and the waiting state is continued until the data is input when the data is not input.

[S5] Data Input When data is input from the input device of the terminal unit by the user, the digital data input to the encoding circuit 32 is input to the wireless terminal device 30 side, as described in the description of FIG. The data is encoded, the multiplier 33 FM-modulates the encoded data by the encoding circuit 32 with the selected frequency generated by the RF oscillator 36, and the multiplier 34 P-modulates the modulated data.
The signal is modulated by the PN code generated by the NG 37 and sequentially transmitted as an SS signal from the antenna 35 to the center device 50, and step S6 is executed. In addition, when a plurality of wireless terminal station devices 30 are set, the wireless terminal station device 30 improves the transmission efficiency on the wireless terminal station device 30 side and the reception processing efficiency on the center device 50 side in the case of successive transmission. A memory may be provided in 30, and SS transmission may be performed for each signal (block) of a fixed length.

[S6] Judgment of End of Data Input It is judged whether or not data input from the input device of the portable terminal unit 20 by the user is ended. If the data input is not ended, step S5 is repeated. When the data input ends, the end code is input. Based on the end code, the wireless terminal station device 30 sends the end signal converted into the SS signal to SS and executes the drive end control of the device.

FIG. 5 is a block diagram showing an example of the configuration of the center device 50 that receives and demodulates the SS data transmitted from the portable radio terminal station device 30 of FIG. The center device 50 includes a receiving antenna 51 and a public line connection terminal 5.
2, amplifier and multiplier 53, correlation circuit 54, demodulation circuit 5
5, output selection circuit 56, local carrier oscillation circuit 5
7, a PNG generation circuit 58, a control circuit 59, a reception frequency selection circuit 60, a PN code selection circuit 61, a data type selection circuit 62, an operation panel 63, a call unit 64, an output switching circuit 65, and output devices 66 to 68. .

The amplifier / multiplier 53 and the local carrier oscillating circuit 57 constitute a signal extracting means, and the correlation circuit 54 and the PNG generating circuit 58 constitute a modulating signal extracting means.
Further, the output devices 66 to 68 are connected in advance to the center device 50 according to the form of transmission data (that is, the form of input data). In the embodiment, image input, voice input, and character / numerical value input are performed. Therefore, the CRT 67, the speaker 68, and the LCD are correspondingly provided on the center device 50 side.
Although the display 69 is connected, it is not limited to these, and the number of connection types is not limited to 3 (note that CRT is used instead of the LCD display for image data and character / numerical data. It is also possible to switch and use one CRT).

In FIG. 5, as in the case of the portable radio terminal station device 30 of FIG. 3 described above, the output selection circuit 56 is based on three types of operation data (input data type, transmission frequency and PN code). Selects an output device, the local carrier oscillator 57 produces a signal of a selected frequency, and the PNG 58 produces a selected PN code. Amplifier and multiplier 5
3 amplifies the received signal and multiplies the amplified received signal by the selected frequency generated by the local carrier oscillator 57 to extract the SS signal from the portable radio terminal station 30. Then, the correlator 54 and the extracted data and PN
A demodulation circuit 55 obtains an input data demodulation signal (digital signal) by obtaining a modulation signal by correlating with the PN code generated in G58. The demodulated digital data is displayed on the output device selected by the output selection circuit 56. In this case, the output switching device 65 can control the output selection circuit 56 to switch the output device.

The data type selection circuit 62 is the operation panel 42.
The input data selection information input from the control panel 59 is sent to the control circuit 59 as digital data, and the reception frequency setting circuit 60 sends the frequency setting information input from the operation panel 42 to the control circuit 59 as digital data. Reference numeral 61 sends the PN code setting information input from the operation panel 42 to the control circuit 59 as digital data.

The assigned frequency of the wireless terminal device 30 and the type of the PN code are set in advance on the side of the center device 50, and the received frequency and the PN code are set simultaneously with the setting of the input data selection information input from the panel 42. It is also possible to configure so that the reception frequency setting information and the PN code setting information on the operation panel 42 and the reception frequency setting circuit 60 and the PN code setting circuit 61 can be omitted. Further, when the data type information is SS-transmitted prior to the SS transmission of the input data, it is received when the assigned frequency of the wireless terminal device 30 and the type of the PN code are set in the center device 50 side in advance. Since the input data selection information can be obtained from the SS signal, the input of the data selection information from the operation panel 42 and the data type selection circuit 62 can be omitted.

The control circuit 59 receives the selected three types of operation data, controls the frequency of the local carrier oscillator 57 and the PN code of the PN code oscillator 58, and controls the center unit 5.
Controls the entire 0. If the output switching device 65 is not provided, switching control of the output selection circuit 56 is also performed. The public line connection terminal 52 is provided as an option and is used when transmitting the data demodulated by the demodulation circuit 55 to a data processing device or an output device or the like in another place via a telephone line.

<Specific Example> FIG. 6 is a perspective view of an embodiment of the portable multimedia input transmission apparatus 10 of the present invention. In FIG. 6A, a simplified keyboard input device 60 (the left as viewed in FIG. 6A) is used as the portable terminal unit 20 of FIG.
Is connected to the wireless terminal device 70 (on the right in FIG. 6B). In this way, the OA equipment such as the image input device and the voice input device can be configured and connected to the wireless terminal device 70 as a terminal unit. The simplified keyboard input device 60 has almost the same configuration as a well-known keyboard input device, and a character keyboard 61, a space key 62, a ten-key pad 63, a display 64, and a control key 65 are shown. The number of lines of the display 64 as the display unit may be one to two character strings because the editing screen can be omitted because the data input can be prioritized and the editing can be performed on the side of the center device 50.
The side surface 72 of the wireless terminal device 70 is provided with an input terminal and a public line terminal (see FIG. 6B) according to the type of input data. The illustrated simple keyboard input device 60 is connected to one of the input terminals. Further, an antenna 71, a display unit 73, a call unit 74, a cursor movement key 75, and a selection key 76 are shown.

When the power of the wireless terminal device 70 is turned on, the type of input data is displayed on the display unit 73 as a menu so that it can be selected by the cursor. The user selects the data type by moving the cursor up and down with the cursor movement key 75 and pressing the selection key at the desired menu position. Similarly, the frequency and PN code are selected. When the data type, frequency, and PN code have been set, the display unit 73 displays a message prompting for data input.

In the above-described embodiments, the terminal device for interposing data is arranged so that the terminal device for inputting data can handle any form of data, and the terminal device is interposed between the terminal device and the center device. However, the present invention is not limited to such a configuration, and may be configured such that each terminal can process input data and transmit Tx as an SS signal. This is because the format of the input data to the center device is unified, so that the data can be input to the center device as long as the data at each terminal is processed according to this format.

For example, as shown in FIG. 7, in addition to the normal keyboard 100 and the display 103 for monitoring the input state, the transmission frequency (Txf) setting switch 1
01 and a PN code setting switch 102 are provided. These switches correspond to the circuits 40 and 41 of FIG. The data selection circuit 39 of FIG. 3 is of course unnecessary in this case. The terminal device 30 in this case is shown in FIG.
As shown in FIG. 3, the coding circuit 201, the mixer 202, the radio frequency oscillator 203, the mixer 204, the PNG 205, and the control circuit 206 are included. Further, when the frequency f or the type of chord to be selected is small, it may be possible to simply select it with a slide switch or the like, but all selectable items are displayed on the screen so that the cursor movement keys can be used for setting. May be. For the PN code,
Not only selection but also arbitrary setting may be possible.

[0040]

As described above, according to the multimedia input system of the present invention, the input OA data is converted into C
In order to quickly transmit and process to the center device having the PU, the terminal unit group corresponding to each data form is used, and the data from these terminal units are connected to the wireless terminal station and SS
Since the data is transmitted by the (Spread Spectrum; spread spectrum) communication method, OA data having various forms can be encoded at the time of data generation, and can be transmitted and processed reliably and quickly with high confidentiality.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a multimedia input system.

FIG. 2 is a block diagram showing a configuration example of a portable input unit group that constitutes the portable multimedia input transmission apparatus of FIG.

FIG. 3 is a block diagram showing a configuration example of a portable radio terminal station device.

FIG. 4 is a flow chart showing a basic operation procedure of a portable multimedia input transmission device including the portable input unit group and the portable wireless terminal device of FIGS. 2 and 3.

FIG. 5 is a block diagram showing a configuration example of a center device.

FIG. 6 is a perspective view of an embodiment of a portable multimedia input transmission device of the present invention.

FIG. 7 is an external view showing another configuration example of the terminal station device.

8 is a block diagram showing a circuit configuration of the device of FIG.

[Explanation of symbols]

 1 multimedia input system 10 portable multimedia input transmitter 20 portable input unit group (input device) 30, 70 portable wireless terminal device 31 input terminal (data type discrimination means) 32 encoding circuit (encoding means) 33 multiplier (frequency modulation means) 34 multiplier (spread spectrum means) 36 radio frequency oscillator (frequency modulation means) 37 PNG (spread spectrum means) 50 center device 52 public line connection terminal (transmission output terminal) 53 amplifier and multiplication Device (signal extraction means) 54 correlation circuit (modulation signal extraction means) 55 demodulation circuit 56 output selection circuit 57 local carrier oscillator circuit (signal extraction means) 58 PNG generation circuit (modulation signal extraction means) 66 to 68 output device

Claims (6)

[Claims] 1. A plurality of input devices having different input data forms, the plurality of input devices are connected to each other, and output data from the plurality of input devices are selectively input, modulated as a spread spectrum signal, and spread spectrum transmitted. A multimedia input data transmitting device comprising: a wireless terminal device. 2. An input device capable of inputting data in a predetermined input form, a conversion circuit for performing a predetermined conversion on data from the plurality of input devices to obtain a converted signal, and modulating the converted signal as a spread spectrum signal. And a multimedia input data transmitting device for performing spread spectrum transmission, and a multimedia input data transmitting device. 3. The multimedia input data transmitting apparatus according to claim 1, wherein the wireless terminal device encodes the input data with a data type discriminating means for obtaining a data type for discriminating the form of the input data. Encoding means for obtaining an input data signal, frequency modulation means for frequency-modulating the input data signal with a given frequency to obtain a modulated signal, and spread spectrum of the modulated signal with a given pseudo-noise code to obtain a spread spectrum signal A spread spectrum means for obtaining the spread spectrum signal, and a transmitting means for transmitting the spread spectrum signal, a multimedia input data transmitting apparatus. 4. The multimedia input data transmitting apparatus according to claim 1 or 2, and a center apparatus that receives a spread spectrum signal from the multimedia input data transmitting apparatus, demodulates and outputs the output data. A multimedia input system characterized by becoming. 5. The center device used in the multimedia input system according to claim 4, wherein the center device receives a transmission signal from an arbitrary multimedia input data transmission device, and a specific multimedia is transmitted from the transmission signal. Signal extraction means for extracting a spread spectrum signal from the input data transmission device, and modulation for extracting a modulation signal by correlating the extracted spread spectrum signal with the pseudo signal given by the specific multimedia input data transmission device. The signal extraction means, the demodulation means for demodulating the modulated signal to obtain the input data signal, the output device connected to each of the input devices for outputting the input data of different forms, and the type of the input data are An output device for discriminating and outputting the input data is selected from the output devices connected to each other. A center device comprising: a force device selecting means. 6. The center device according to claim 5,
Furthermore, the center device having a transmission output terminal for transmitting the output from the demodulation means.