Patent Application
20070297407
Exemplary embodiments of the present invention are described in detail below with reference to the accompanying drawings.
The controller 2 is an arithmetic circuit such as a central processing unit (CPU) that controls an operation of the communication apparatus 1 based on an internal state of the communication apparatus 1, a control signal input from the control interface 3, and control information included in a reception signal received from a transmission path 4. The frame generator 5 generates a data frame to be transmitted to the transmission path 4 from transmission data transmitted from the upper interface 6 or a control-information transmission request notified from the controller 2. The transmission circuit 7 converts the data frame generated by the frame generator 5 to a signal in a format transmitted to the transmission path. According to a first embodiment of the present invention, the transmission circuit 7 is formed of a modulator 8 such as a multicarrier or an orthogonal frequency division multiplexing (OFDM) modulator, a digital-to-analog (D/A) converter 9 that converts a digital signal to an analog signal, a filter 10 that removes unnecessary components in the analog signal to be transmitted, and a amplifier 11 that amplifies power of the transmission signal.
The reception circuit 12 restores the signal received from the transmission path to the data frame, and is formed of a amplifier 13 that amplifies the received signal, a filter 14 that removes a noise component from the received analog signal, an analog-to-digital (A/D) converter 15 that converts an analog signal to a digital signal, and a demodulator 16 that demodulates a signal demodulated to the multicarrier or OFDM signal. The frame analyzer 17 analyzes the received data frame and transmits the control information obtained as the analysis result and the received data to the controller 2 and the upper interface 6. The address storage unit 18 stores an address of the apparatus according to the first embodiment, as the address of the apparatus, an address including at least a first identifier for identifying a group to which the apparatus belongs and a second identifier for specifying an individual apparatus is used.
A1A2A3A4A5A6A7A8=00000000 is prohibited to be allocated to a specific group, and is used as the first identifier of a destination address at the time of transmission in a predetermined broadcast function and the first identifier of a source addresssource address when the apparatus, whose address has not been set, transmits the control information and the like.
B1B2B3B4B5B6B7B8B9B10B11B12B13B14B15B16=0000000000000000 is prohibited to be allocated to a specific apparatus, and is used as the second identifier of a destination address at the time of transmission in the predetermined broadcast function and the second identifier of a source addresssource address when the apparatus, whose address has not been set, transmits the control information and the like.
The frame ID is an 8-bit value, and the respective apparatuses use a value arbitrarily generated at the time of transmitting the data frame for the first time, and thereafter, use a value obtained by adding 1 to the frame ID used last time, every time the data frame is transmitted. After a series of bits 11111111 is used as the frame ID, a series of bits 00000000 is used at the time of transmitting the data frame next.
The frame code is a 1-bit value, and is set to 0 when general data is transmitted, and set to 1 when the control information for controlling the operation of another communication apparatus. The data contains arbitrary data in the data frame having the frame code of 0, and control code indicating the type of the control information to be transmitted and control data determined for each type of the control information in the data frame having the frame code of 1.
The controller 2 refers to the address storage unit 18 at the time the communication apparatus 1 is turned on to check address setting state (step S1). When the address of the communication apparatus 1 is not stored in the address storage unit 18 (NO at step S2), the controller 2 instructs the frame generator 5 to broadcast a first-identifier request signal to other apparatuses. The frame generator 5 generates a data frame of the first-identifier request signal and sends the data frame to the transmission circuit 7. The transmission circuit 7 modulates the data frame, converts the data frame to an analog signal, removes unnecessary components therefrom, and amplifies the signal power to transmit the analog signal to the transmission path 4 (step S3).
If the address of the communication apparatus 1 is stored in the address storage unit 18 (YES at step S2), the controller 2 performs a normal operation.
After broadcasting the first-identifier request signal, the communication apparatus 1 waits for receiving a first-identifier notification signal in response to the broadcast first-identifier request signal (step S4). Upon receipt of a first-identifier notification signal (YES at step S4), the frame analyzer 17 analyzes the data frame of the first-identifier notification signal. When the data frame has a frame code 1, and contains a control code 0010 and control data including a frame ID of a first-identifier request signal that matches that of the first-identifier request signal broadcasted previously (YES at step S5), the communication apparatus 1 stores the notified first identifier in the address storage unit 18 as its own first identifier (step S6).
According to the first embodiment, the communication apparatus 1, whose address has not been set, broadcasts a first-identifier request signal. In response to the broadcast first-identifier request signal, the communication apparatus 1 is notified of a first identifier, and stores the notified first identifier to use it for communication thereafter. Accordingly, a user can set the first identifier without troublesome operation of setting the first identifier. Thus, a possibility that a first address is wrongly set can be avoided.
In
In this manner, according to the second embodiment, the communication apparatus 1 notifies other apparatuses that setting of a first identifier is completed after the process in the first embodiment. Thus, the other apparatuses can recognize the completion of the address setting and avoid unnecessary transmission of a signal for notifying a first identifier.
According to the third embodiment, having received a first-identifier request signal, the communication apparatus 300 notifies another apparatus of its own first identifier in response to input from the input unit 30. Accordingly, a user of the communication apparatus 300 can assign the same first identifier as its own identifier to a new apparatus without troublesome operation of inputting an address.
On the other hand, when the preset time has already been passed (YES at step S31), the communication apparatus 400 ignores the input received through the input unit 30, and does not respond to the first-identifier request signal.
According to the fourth embodiment, when a preset time has passed after receipt of a first-identifier request signal, input requesting to transmit a first-identifier notification signal is invalidated. Accordingly, unnecessary transmission of a signal due to incorrect input or the like by a user can be prevented.
After receiving a first-identifier request signal (step S21), when receiving through the input unit 30 input requesting to transmit a first-identifier notification signal before receiving an identifier-setting completion signal (NO at step S41, YES at step S22), the communication apparatus according to the fifth embodiment performs the process at step S23 previously described in connection with
On the other hand, when receiving an identifier-setting completion signal after receiving a first-identifier request signal, the communication apparatus according to the fifth embodiment checks the field of control data contained in the identifier-setting completion signal. If the control data of the identifier-setting completion signal includes a frame ID that matches that of the first-identifier request signal. (YES at step S41), the communication apparatus ignores the input received through the input unit 30, and does not respond to the first-identifier request signal.
According to the fifth embodiment, when an identifier-setting completion signal is received after receipt of a first-identifier request signal, input requesting to transmit a first-identifier notification signal is invalidated. Accordingly, unnecessary transmission of a signal due to incorrect input or the like by a user can be prevented.
After receiving a first-identifier request signal (step S21), when receiving through the input unit 30 input requesting to transmit a first-identifier notification signal before receiving an identifier-setting completion signal and before a preset time has passed (NO at step S41, NO at step S31, YES at step S22), the communication apparatus according to the sixth embodiment performs the process at step S23 previously described in connection with
On the other hand, when receiving an identifier-setting completion signal after receiving a first-identifier request signal, the communication apparatus according to the sixth embodiment checks the field of control data contained in the identifier-setting completion signal. If the control data of the identifier-setting completion signal includes a frame ID that matches that of the first-identifier request signal. (YES at step S41), the communication apparatus ignores the input received through the input unit 30. If the frame ID does not match that of the first-identifier request signal (NO at step S41), the communication apparatus checks whether the preset time has passed. When the preset time has already been passed (YES at step S31), the communication apparatus ignores the input received through the input unit 30, and does not respond to the first-identifier request signal.
According to the sixth embodiment, when an identifier-setting completion signal is received and when a preset time has passed after receipt of a first-identifier request signal, input requesting to transmit a first-identifier notification signal is invalidated. Accordingly, unnecessary transmission of a signal due to incorrect input or the like by a user can be prevented.
The process shown in
On the other hand, upon receipt of a first-identifier notification signal transmitted by another apparatus, which contains control data including a frame ID that matches that of the first-identifier request signal received at step S21 (YES at step S51), the communication apparatus ignores the input received through the input unit 30, and does not respond to the first-identifier request signal.
According to the seventh embodiment, when a first-identifier notification signal transmitted by another apparatus is received after receipt of a first-identifier request signal, input requesting to transmit a first-identifier notification signal is invalidated. Accordingly, unnecessary transmission of a signal due to incorrect input or the like by a user can be prevented.
First, the apparatus A, which has been turned on (step S61), checks address setting state thereof (step S62), and broadcasts a first-identifier request signal (step S63).
After receiving the first-identifier request signal (step S64-1), the apparatus B receives input requesting to transmit a first-identifier notification signal (step S65). The apparatus B broadcasts the first-identifier notification signal in response to the input (step S66). The apparatus A receives the first-identifier notification signal transmitted by the apparatus B (step S67-1), stores a first identifier notified by the first-identifier notification signal in the address storage unit 18 (step S69), and broadcasts an identifier-setting completion signal (step S70).
On the other hand, after receiving the first-identifier request signal (step S64-2), the apparatus C receives the first-identifier notification signal transmitted by the apparatus B (step S67-2). Thus, the apparatus C ignores input requesting to transmit a first-identifier notification signal (step S68).
The apparatus D, which has received the first-identifier request signal (step S64-3) but could not receive the first-identifier notification signal transmitted by the apparatus B due to, for example, a communication error, receives the identifier-setting completion signal transmitted by the apparatus A (step S71), and ignores input requesting to transmit a first-identifier notification signal (step S72).
The apparatus E, which has received the first-identifier request signal (step S64-4), but could not receive the first-identifier notification signal transmitted by the apparatus B and the identifier-setting completion signal transmitted by the apparatus A due to, for example, a communication error, ignores input requesting to transmit a first-identifier notification signal (step S74) when a preset time has passed (step S73).
With this configuration, a user can assign the same first identifier as that of an existing apparatus to a new apparatus without troublesome operation of inputting an address. Accordingly, unnecessary transmission of a signal due to incorrect input or the like by a user can be prevented.
Thereafter, when a first identifier notified by the process at steps S4 to S6 is stored in the address storage unit 18, the communication apparatus 900 terminates the indication by the output unit 32 under the control of the controller 2 (step S82).
According to the ninth embodiment, during a procedure for setting a first identifier, the communication apparatus 900 indicates that a first identifier is in the process of being set. Accordingly, a user can determine whether the first identifier has been set and the process is normally complete.
Upon receipt of an identifier-setting completion signal corresponding to the first-identifier notification signal previously transmitted (YES at step S92), the communication apparatus 1 terminates the indication by the output unit 33 (step S93).
According to the tenth embodiment, during a period from transmission of a first-identifier notification signal until receipt of an identifier-setting completion signal in response thereto, the communication apparatus 1000 indicates that a first-identifier notification signal has been transmitted. Therefore, a user can determine whether the process is normally complete.
First, the apparatus A, which has been turned on (step S101), checks address setting state thereof (step S102), and broadcasts a first-identifier request signal (step S103). The apparatus A starts indicating that a first identifier is in the process of being set (step S107), and waits for receiving a first-identifier notification signal.
On the other hand, after receiving the first-identifier request signal (step S104), the apparatus B receives input requesting to transmit a first-identifier notification signal (step S105). The apparatus B transmits the first-identifier notification signal in response to the input (step S106). The apparatus B then starts indicating that the first-identifier notification signal has been transmitted (step S112), and thereafter, waits for receiving an identifier-setting completion signal.
Upon receipt the first-identifier notification signal (step S108), the apparatus A stores a first identifier notified by the first-identifier notification signal in the address storage unit 18 (step S109), and terminates indicating that a first identifier is in the process of being set (step S110). The apparatus A then transmits an identifier-setting completion signal (step S111).
Upon receipt of the identifier-setting completion signal corresponding to the first-identifier notification signal (step S113), the apparatus B terminates indicating that the first-identifier notification signal has been transmitted (step S114).
The state of the output unit of the apparatus A and the apparatus B is explained specifically. For example, when the process for setting a first identifier is complete normally, indication by the output units of the apparatus A and the apparatus B are both terminated.
When the apparatus B cannot normally receive a first-identifier request signal transmitted from the apparatus A, the output unit of the apparatus B displays no indication, while the output unit of the apparatus A displays indication. When the apparatus A and another communication apparatus having the same function as that of the apparatus A substantially simultaneously transmit a first-identifier request signal, and the apparatus B transmits a first-identifier notification signal to the other communication apparatus in response to the first-identifier request signal therefrom, a first identifier is not set for the apparatus A. Consequently, the output unit of the apparatus B terminates indication, while the output unit of the apparatus A keeps displaying indication.
When another communication apparatus having the same function as that of the apparatus B transmits a first-identifier notification signal in response to a first-identifier request signal transmitted by the apparatus A, and a first identifier unintended by a user is set for the apparatus A, the output unit of the apparatus A terminates indication, while the output unit of the apparatus B keeps displaying indication.
When the apparatus A cannot normally receive a first-identifier notification signal transmitted from the apparatus B, and a first identifier is not set for the apparatus A, the output units of both the apparatus A and B keep displaying indication.
According to the eleventh embodiment the communication system includes, for example, the communication apparatus according to the ninth embodiment and the communication apparatus according to the tenth embodiment. With this configuration, a user can confirm whether a first identifier has been set properly.
Thereafter, the communication apparatus 1012 measures the elapsed time after transmission of the identifier-conflict detection signal using the timer 36. If an identifier-unavailability notification signal is not received when a preset time has passed (NO at step S124), the communication apparatus 1012 stores the generated arbitrary first identifier in the address storage unit 18 (step S6), and uses the first identifier generated therein as its own first identifier.
On the other hand, if an identifier-unavailability notification signal is received before the preset time has passed since the transmission of the identifier-conflict detection signal (NO at step S125, YES at step S124), the communication apparatus 1012 repeatedly generates a new arbitrary first identifier and broadcasts an identifier-conflict detection signal for notifying a newly generated arbitrary first identifier until an identifier-unavailability notification signal is not received within the preset time. The communication apparatus 1012 thus stores the arbitrary first identifier if not receiving an identifier-unavailability notification signal (step S6), and uses the first identifier generated therein as its own first identifier.
According to the twelfth embodiment, the communication apparatus 1012 generates an arbitrary first identifier, and checks whether the generated arbitrary first identifier is already used as a first identifier of another communication apparatuses in the network. After checking that the arbitrarily generated first identifier is not used, the communication apparatus 1012 uses it for communication. A determination as to whether the above function is to be used is made based on input from a user. Thus, the user can classify a new communication apparatus in a group of existing communication apparatuses by setting the same first identifier as that of the existing communication apparatuses or create a new group to classify the new communication apparatus in the new group.
According to the thirteenth embodiment, an arbitrary first identifier is generated based on a random number. Accordingly, the generated arbitrary first identifier has a random value, which reduces a possibility that a first identifier that has already been used is generated. Therefore, the time required for setting a first identifier can be reduced.
The communication apparatus 1014 inputs output of the A/D converter 15, which converts a signal voltage on a transmission path to digital information, to the first identifier generator 35. The first identifier generator 35 generates an arbitrary first identifier by combining part or all of bits of the output of the A/D converter 15. Because there is noise on the transmission path, the signal voltage on the transmission path having converted to the digital information by the A/D converter 15 at arbitrary timing fluctuates irregularly according to the conversion timing. Therefore, the arbitrary first identifier generated by combining part or all of bits of the output of the A/D converter 15 has a random value.
According to the fourteenth embodiment, the communication apparatus 1014 generates an arbitrary first identifier by combining part or all of bits of a result of conversion of a signal voltage on the transmission path to digital information. Therefore, an arbitrary first identifier having a random value can be easily obtained.
According to the fifteenth embodiment, the communication apparatus 1015 automatically determines whether there is duplication of the same first identifier. Upon determining that a first identifier notified by another apparatus is already used, the communication apparatus 1015 broadcasts a signal for notifying this matter. Accordingly, a user is not required to check whether there is duplication of the same first identifier.
Even when a first identifier notified by an identifier-conflict detection signal matches its own first identifier (YES at step S131), the communication apparatus according to the sixteenth embodiment does not broadcast an identifier-unavailability notification signal if receiving an identifier-unavailability notification signal corresponding to the identifier-conflict detection signal transmitted by another apparatus (YES at step S141), or if receiving an identifier-setting completion signal (YES at step S142).
According to the sixteenth embodiment, when receiving an identifier-unavailability notification signal transmitted by another apparatus, the communication apparatus does not broadcast an identifier-unavailability notification signal. Accordingly, an identifier-unavailability notification signal can be prevented from redundantly transmitted, which prevents an increase in useless communication load.
In
In the apparatus B, upon receipt of the identifier-conflict detection signal from the apparatus A (step S153-1), the address comparator 38 compares the notified arbitrary first identifier with the first identifier of the apparatus B (step S154-1). When the notified arbitrary first identifier matches the first identifier of the apparatus B (step S155-1), the apparatus B broadcasts an identifier-unavailability notification signal (step S156).
In the apparatus C, it is detected as in the apparatus B that the arbitrary first identifier notified by the apparatus A matches its own first identifier (step S153-2, S154-2, S155-2). However, having received the identifier-unavailability notification signal from the apparatus B (step S157-2), the apparatus C does not transmit an identifier-unavailability notification signal.
The apparatus A having received the identifier-unavailability notification signal from the apparatus B (step S157-1) generates a new arbitrary first identifier (step S158), and notifies the apparatuses B and C of the new arbitrary first identifier by an identifier-conflict detection signal (step S159).
The apparatuses B and C receive the identifier-conflict detection signal transmitted from the apparatus A (step S160-1, step S160-2), and compares the notified new arbitrary first identifier with their own first identifiers (step S161-1, step S161-2). The apparatuses B and C each confirm that the new arbitrary first identifier does not match its own first identifier (step S162-1, step S162-2), and do not transmit a signal corresponding to the identifier-conflict detection signal.
When an identifier-unavailability notification signal is not received within a preset time after transmission of the identifier-conflict detection signal (step S163), the apparatus A stores the arbitrary first identifier (step S164), and uses the first identifier for communication thereafter.
With this configuration, a first identifier that has not yet assigned to another apparatus can be automatically provided to a new apparatus.
Although the invention has been described with respect to a specific embodiment for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-174397 | Jun 2006 | JP | national |
