JP2001308775A - Communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate communication among in-vehicle apparatuses, and among the in-vehicle apparatuses and the outside. SOLUTION: The in-vehicle apparatuses are connected by an IEEE1394 serial bus 34, and a radio transmission and reception circuit 14 is connected through an IEEE1394 serial bus 20 and a radio/IEEE1394 conversion circuit 18. A security circuit 16 to manage the authentication of an apparatus ID and a password or the like is connected to the radio transmission and reception circuit 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system, and more particularly, to a communication system for communicating data between devices inside and outside a vehicle.

[0002]

2. Description of the Related Art A personal computer and various peripheral devices are connected via digital interfaces such as SCSI, USB, and IEEE1394. For example,
The SCSI bus is used to connect a computer with a hard disk, an image scanner, a magneto-optical disk device, and the like. USB is used to connect relatively slow image scanners, digital still cameras, terminal adapters, printers, and the like. IEEE13
94 has a high speed of 400 Mbits / s.
It is suitable for transmitting stream data such as data and audio data in real time. Currently, video / audio data is transmitted between a digital video camera and a computer.
It is being used to transfer audio data.

In recent years, many electronic devices such as an AM / FM tuner, an audio amplifier, a CD player, a speaker, an air conditioner, a GPS positioning system (car navigation system), and a video monitor are mounted in a car. However, although the AM / FM tuner, the audio amplifier, the CD player, and the speaker constitute an audio system, they have not yet reached an organic relationship with other devices, that is, a network for exchanging data with each other.

[0004]

The advantages of interconnecting the above-described electronic devices in a vehicle are numerous. What had to be individually operated can also be unifiedly operated in one method by, for example, a voice recognition system. Since the driver always needs to pay attention to the surroundings, improvement in operability directly leads to improvement in safety.

[0005] In addition, there are a number of electronic devices related to the operation of the vehicle itself, for example, an in-vehicle computer for controlling each unit in the vehicle, and a number of sensors for detecting the status of each unit. It would be very convenient if the above electronic devices could be connected organically. For example, when an abnormality occurs in a vehicle, in the conventional example, only a lamp is lit on a predetermined display device, but it is displayed in more detail on a screen of a video monitor, and furthermore, voice is output from a speaker. It will also be possible to warn.

[0006] Further, communication with the outside is currently being put to practical use by using both a GPS positioning system and a mobile phone or a car phone. However, the main uses are acquisition of congestion information (ATIS), connection to the Internet, and transmission of position information between devices of the same manufacturer.

An object of the present invention is to provide a communication system capable of freely exchanging data between in-vehicle devices and between in-vehicle devices and external devices.

[0008]

SUMMARY OF THE INVENTION A communication system according to the present invention is a communication system mounted in a car,
A data bus capable of freely transmitting V data and control data, a plurality of AV devices connected to the data bus, wireless communication means connected to the data bus, and wirelessly communicating data with external devices; It is characterized by comprising a partner device and a partner confirmation unit for confirming a user of the partner device by a device ID and a password by wireless communication by the wireless communication unit.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings.

[0010] Before describing the embodiments, IEEE 1394
The configuration and operation of the serial bus will be briefly described.

With the advent of home digital VTRs and DVDs, it has become necessary to transfer data with a large amount of information such as video data and audio data in real time. An interface developed from such a viewpoint is IEEE 1394-1995 (High Pe
rformance Senal Bus). Hereinafter, it is called a 1394 serial bus.

FIG. 7 shows an example of a network system constituted by an IEEE 1394 serial bus.
Equipment A, B, C, D, E, F, G, H, AB
, A-C, B-D, D-E, C-F, CG
And CH are connected by a twisted pair cable of a 1394 serial bus. These devices A to H are, for example, personal computers, digital VTRs, DVD devices, digital cameras, hard disks, monitors, and the like. According to the IEEE 1394 standard, a daisy chain method and a node branch method can be mixed as a connection method between devices, and connection with a high degree of freedom is possible.

Each of the devices A to H has its own unique ID, and recognizes each other.
One network is configured within a range connected by a 94 serial bus. In other words, only by sequentially connecting each digital device with one IEEE 1394 serial bus cable, each device plays a role of a relay and forms one network as a whole. Plug and Play (Pl), which is also a feature of the IEEE 1394 serial bus
ug & Play) function, when the cable is connected to the device, the device and the connection status are automatically recognized.

When any of the devices A to H is disconnected or a new device is connected, a bus reset is automatically executed,
The previous network configuration is reset, and a new network is rebuilt. With this function, IE
With the EE1394 serial bus, the configuration of the network can be freely changed and automatic recognition can be performed.

The data transfer rate is 100/200/40
0 Mbps is stipulated, and devices having a higher transfer rate support a lower transfer rate so that they can be connected to each other without any trouble.

The IEEE 1394 serial bus transfers asynchronous data (asynchronous data) such as a control signal and real-time synchronous data (isochronous data) such as video data and audio data as data transfer modes. An isochronous transfer mode is provided. Asynchronous data and isochronous data are mixed in each cycle (usually 125 μs in one cycle), following a cycle start packet (CSP) indicating the start of a cycle, and prioritizing the transfer of isochronous data in the cycle. And transferred.

FIG. 8 is a schematic block diagram showing the configuration of the IEEE 1394 interface. The IEEE 1394 serial bus has a layer (hierarchical) structure as a whole. As shown in FIG. 8, the lowest order is a cable of the IEEE 1394 serial bus, and there is a connector port to which a connector of the cable is connected, and a physical layer and a link layer are provided as hardware thereon.

[0018] The hardware section is substantially composed of an interface chip. The physical layer performs coding and control related to connectors, and the like, and the link layer controls packet transfer and cycle time.

The transaction layer of the firmware section manages data to be transferred (transacted) and outputs commands such as reading and writing. The serial bus management manages the connection status and ID of each connected device, and manages the configuration of the network. The functions of a bus manager and an isochronous resource manager described later are included in the serial bus management.

The application layer of the software section differs depending on the software used. The application layer also defines how data is loaded on the interface, and is specifically defined by a protocol such as an AV protocol.

FIG. 9 is a schematic diagram of an address space in the IEEE 1394 serial bus. IEEE 1394
Each device (node) connected to the serial bus always has a 64-bit address unique to each node. This address can refer not only to itself but also to other nodes. Thereby, communication in which the other party is specified becomes possible.

The addressing of the IEEE 1394 serial bus is based on the IEEE 1212 standard.
The first 10 bits of the 64 bits are used to specify a bus number, and the next 6 bits are used to specify a node ID number. The remaining 48 bits are the address given to the device, and can be used as an address space unique to each device. Part 48
The last 28 bits of the bits store, as a unique data area, information for identifying each device and designating use conditions.

FIG. 10 shows a sectional view of an IEEE 1394 serial bus cable. The IEEE 1394 serial bus cable has a power supply line in addition to two twisted pair signal lines. As a result, power can be supplied to a device having no power supply, a device whose voltage has been reduced due to a failure, and the like. The voltage of the power supply line is 8 to 40V, and the current is the maximum current DC
It is specified as 1.5A.

Referring to FIG. 11, the DS-Link encoding system employed in the IEEE 1394 serial bus will be described. The IEEE-1394 serial bus uses DS-
A Link (Data / Strobe Link) coding scheme is employed. This DS-Link encoding method is suitable for high-speed serial data communication, and requires two signal lines. Main data is sent to one of the twisted pairs, and a strobe signal is sent to the other twisted pair.
The receiving side can reproduce the clock by taking the exclusive OR of the data and the strobe.

The advantages of using the DS-Link coding method include higher transfer efficiency compared to other serial data transfer methods, the fact that a PLL circuit is not required, so that the circuit size of the controller LSI can be reduced. Since there is no need to send information indicating that the apparatus is in an idle state when there is no data to be transmitted, power consumption can be reduced by setting the transceiver circuit of each device to a sleep state.

FIG. 12 is a schematic diagram showing a network configuration of the IEEE 1394 serial bus. IEEE 1394
In a network, a node connected to only one node is called a leaf, and a node connected to a plurality of nodes is called a branch.

Next, the characteristic operation of the IEEE 1394 serial bus will be sequentially described. The bus reset sequence is as follows. In the IEEE 1394 serial bus, each connected device (node) is given a node ID, which is recognized as a network element. For example, when there is a change in the network configuration due to an increase or decrease in the number of nodes due to insertion / removal of a node or power on / off, etc., and it is necessary to recognize a new network configuration, each node that has detected the change places a bus on the bus. A reset signal is transmitted to enter a mode for recognizing a new network configuration. New participation in the network or withdrawal from the network is based on IEEE 139
It can be detected by a change in the bias voltage on the 4-port board.

At a node to which a bus reset signal has been transmitted from a certain node, the physical layer receives the bus reset signal, and at the same time, transmits the occurrence of a bus reset to the link layer and transmits the bus reset signal to another node. I do. After all the nodes finally detect the bus reset signal, the bus reset is activated. The bus reset may be started by hardware detection due to cable insertion / removal and network abnormality, or may be started by directly issuing a command to the physical layer by host control from a protocol or the like.

When the bus reset is activated, the data transfer is suspended, the data transfer during this period is waited, and after the end, the data transfer is resumed under a new network configuration.

The determination sequence of the node ID will be described.
After the bus reset, each node gives each node an ID to build a new network configuration. A general sequence from the bus reset to the determination of the node ID will be described with reference to FIG. 13, FIG. 14, and FIG.

FIG. 13 shows a flowchart of a series of bus operations from the occurrence of a bus reset to the determination of the node ID and the start of data transfer. The occurrence of a bus reset in the network is constantly monitored (S1). When a bus reset occurs due to power on / off of any of the nodes (S1), in order to know the connection status of a new network from the network reset state,
A parent-child relationship is declared between the connected nodes (S2). When the parent-child relationship is determined between all nodes (S3), one route is determined (S4). When the route is determined (S4), IDs are sequentially set for all nodes in a predetermined node order (S5, S6). When IDs are set for all nodes (S6), all nodes are set. Has recognized the new network configuration, and is ready for data transfer between nodes, and data transfer is started (S7). After S7, the process returns to S1, and the bus reset is monitored again.

FIG. 14 is a detailed flowchart of the process from the bus reset to the determination of the route. When a bus reset occurs (S11), the network configuration is reset once. As a first step of re-recognizing the reset network connection status, a flag indicating a leaf (node) is set for each device (S12). Each device checks how many ports of its own are connected to other nodes (S13). According to the number of ports connected to other nodes, the number of undefined (parent-child relationship is not determined) ports is examined in order to start the declaration of the parent-child relationship from now on. Immediately after the bus reset, the number of ports connected to other nodes is equal to the number of undefined ports, but the number of undefined ports decreases as the parent-child relationship is determined.

Immediately after a bus reset, only a leaf can declare a parent-child relationship first. The leaf declares to the node connected thereto that it is a child and the other party is a parent (S15).

Immediately after the bus reset, since the number of undefined ports is 2 or more (S14), the branch node sets a flag indicating the branch (S16).
Wait for the parent's notice in the parent-child relationship declaration from the leaf (S1
6). When the parent's notice is received, the number of undefined ports decreases by 1,
It returns to S14. While the number of undefined ports is 2 or more, S1
6. Repeat S17.

When the number of undefined ports becomes 1 (S1
4) It is possible to declare itself as a child to a node connected to the remaining port (S1).
5). Finally, a node having an undefined port number of 0 (for example, any one branch or exceptionally a leaf (a leaf that could not be declared as a child because it did not operate quickly even though a child could be declared)). ) (S14), the route flag is set (S18), and the route is recognized as a route (S14).
19).

In this way, after the bus reset, the parent-child relationship is established between all nodes in the network.

FIG. 15 is a flowchart showing the procedure from the determination of the route to the end of the ID setting. First, according to the sequence shown in FIG. 13 and FIG.
Assigned to leaf, branch or root. The processing differs depending on which one is used (S21). ID first
Can be set for a leaf, and IDs are set in ascending order of the leaf, branch, and route (node number = 0).

The number N of leaves existing in the network
(N is a natural number) is set (S22). Each leaf requests the root to give an ID (S23). If there are multiple requests, the route arbitrates these requests (S24) and gives the winning node an ID number,
The losing node is notified of the result of the failure (S25).
The leaf that failed to acquire the ID sends an ID request to the root again, and repeats the same operation (S26, S23). I
The leaf that has acquired D broadcasts the acquired ID information to all nodes (S27), and leaves counter N
Is reduced by 1 (S28). Until N becomes 0 (S29),
S23, S26, S27 and S28 are repeated.

Finally, all leaves broadcast ID information (S27), and when N = 0 (S28),
Shift to branch ID setting. The setting of the branch ID is the same as that of the leaf. That is, the number M of branches existing in the network (M is a natural number) is set (S3).
0). Each branch requests the root to give an ID (S31). If there are multiple requests, the root arbitrates these requests (S32), and the one node that won wins the I following the ID previously set on the leaf or branch.
A D number is given, and the losing node is notified of the failure result (S33). The branch for which ID acquisition failed,
An ID request is sent to the root, and the same operation is repeated (S3
4, S31). The branch that has acquired the ID broadcasts the acquired ID information to all nodes (S3).
5) The branch counter M is decremented by 1 (S36). Until M becomes 0 (S37), S31, S34, S35, S
Repeat 36.

M = 0, that is, all branches are nodes I
When D is acquired (S37), the root acquires the ID following the ID given to the leaf or branch immediately before as its own ID (S38), and broadcasts it to all other nodes (S39).

In this way, the parent-child relationship is determined between all nodes connected to the network, and the IDs of all nodes are determined.

In the example of the network configuration shown in FIG. 12, the node B is the root. Nodes A and C are directly connected below the node B, nodes D are directly connected below the node C, and nodes E and F are directly connected below the node D. A procedure for determining a root node and a node ID in this hierarchical structure will be described. After the bus reset, first, in order to recognize the connection status of each node, a parent-child relationship is declared between the directly connected ports of each node. In this parent-child relationship, the upper level of the hierarchical structure is the parent, and the lower level is the child.

In FIG. 12, the node A first declares the parent-child relationship after the bus reset. Basically, 1
A node (leaf) in which a node connects to only one port can declare the parent-child relationship first. The leaf is obviously located at the edge of the network. Is recognized, and the parent-child relationship is determined from the node that operates earlier in that. Node (AB) declaring parent-child relationship
Between them, the port of the node A) is set as a child, and the port of the other side (node B) is set as a parent. Thus, a child-parent is determined between nodes AB, a child-parent is determined between nodes ED, and a child-parent is determined between nodes FD.

Further up in the hierarchy, this time, among the nodes (branches) having a plurality of connection ports, the parent-child relationship is declared further higher in order from the node that received the declaration of the parent-child relationship from another node. Go. In FIG. 12, first, the parent-child relationship of the node D is determined between the DE and the DF, and then the parent-child relationship for the node C is declared. As a result, node D-
A child-parent is determined between C. The node C that has received the declaration of the parent-child relationship from the node D declares the parent-child relationship to the node B connected to another port. As a result, a child-parent is determined between the nodes CB.

In this way, the hierarchical structure of the parent-child relationship as shown in FIG. 12 is determined. The node B that has become the parent in all finally connected ports becomes the root node. There is only one route in one network configuration.

If the node B that has received the parent-child relationship declaration from the node A has declared the parent-child relationship with another node C at an early timing, the node C may become the root. That is, depending on the timing of the parent-child declaration, there is a possibility that another node C or D may become the root, and the root node is not always constant even in the same network configuration.

After the root node is determined, the ID of each node is determined. All nodes notify their determined node IDs to all other nodes (broadcast function). The information to be broadcast includes its own node number, information on the connected position, the number of ports it has, the number of ports it has connected, and information on the parent-child relationship of each port.

The procedure for assigning a node ID to each node is as follows:
As described above. That is, a number that increases in order from node number = 0 is assigned to each leaf node, and then a node number that follows each branch is assigned. The root owns the highest node ID number.

In this way, the node I of the entire hierarchical structure
The assignment of D is completed, the network configuration is reconstructed, and the bus initialization operation is completed.

Next, the arbitration process of the bus use right will be described. In the IEEE 1394 serial bus, the right to use the bus is always arbitrated prior to data transfer. The IEEE 1394 serial bus forms a logical bus-type network that transmits the same signal to all devices in the network by each device relaying the transferred signal, so arbitration is necessary to prevent packet collision. Becomes This allows only one node to transfer data at any given time.

FIGS. 16 and 17 show the relationship between the request for the right to use the bus and the permission for the request. When arbitration begins, one or more nodes request a bus right towards the parent node. In FIG. 16, nodes C and F are nodes requesting the right to use the bus. Upon receiving this, the parent node (node A in FIG. 16) further requests (ie, relays) the right to use the bus toward the parent node. This request is finally delivered to the route.

The root node that has received the bus use right request is
Determine which nodes will use the bus. This arbitration is the exclusive responsibility of the root node,
The node that has won the arbitration is granted bus use permission. In FIG. 17, use permission is given to the node C, and use of the node F is denied. The route sends a data prefix (DP) packet to the node that has lost arbitration to indicate that the request to bus has been rejected. The rejected node's request to use the bus is waited for the next arbitration.

As described above, one node that has won the arbitration and obtained the permission to use the bus can start data transfer thereafter.

FIG. 18 shows a detailed flowchart of the arbitration process. Before a node can initiate a data transfer,
The bus must be idle. In order to recognize that the bus is currently idle after the data transfer that has been performed earlier is completed, a predetermined idle time gap length (for example, a sub-action・ It is only necessary to wait for the gap to elapse.
It is confirmed whether or not a time corresponding to a predetermined gap length according to transfer data such as asynchronous data and synchronous data has elapsed (S41). This is because a request for the right to use the bus required to start the transfer cannot be issued unless the time corresponding to the gap length has elapsed.

When the time corresponding to the predetermined gap length has elapsed (S41), it is determined whether there is data to be transferred (S42). If there is data (S42), a bus use right is requested to the route (S43). This bus use right request signal is finally delivered to the route while relaying each device in the network as shown in FIG. If there is no data to be transferred (S42), the process stands by.

Upon receiving one or more bus use right request signals (S44), the route checks the number of nodes requesting the bus use right (S45). If the number of nodes requesting the right to use the bus is 1, the node is permitted to immediately use the bus, and a permission signal is transmitted to the node (S48).
When the number of requests for the bus use right is plural (S4
5), the route determines one node that is permitted to use the bus (S46). This arbitration work does not always obtain permission from the same node, but is a fair one in which each node is given equal rights.

A permission signal is transmitted to one node whose route has permitted use from among the plurality of nodes that have requested the bus use right (S47, S48). The node permitted to use the bus starts transferring data (packets) immediately after receiving the permission signal.

A DP (data prefix) packet indicating arbitration failure is transmitted to the other nodes that have lost arbitration (S47, S49). The node that has received the DP packet returns to S41, waits for the elapse of the predetermined gap length, and requests the right to use the bus again.

The cycle master is a node that periodically generates a cycle start signal. The cycle start signal is called a cycle start and is sent from the cycle master to each node as a cycle start packet at a special interval (usually 125 μS) set by a cycle sync source. Sent. The cycle start is
Usually, every 125 μS, but depending on the transfer state, 125
It may be transmitted with a delay from μS.

The bus manager includes advanced power management, serial bus performance optimization, topology management, data transfer rate management, and cycle master control and performance as the bus manager functions included in the serial bus management. Performs functions such as optimization. A bus manager is a node that can provide management functions to other nodes. The bus manager node can also be the next isochronous resource manager node at the same time.

The isochronous resource manager is a node having, as an isochronous resource manager function included in the serial bus management, a function of managing allocation of an isochronous data transfer band and a channel number in isochronous transfer. The only isochronous resource manager that performs this management exists on the bus, and after the bus initialization phase, one is dynamically selected from a plurality of nodes having the isochronous resource manager function.
The decision of the bus manager is also made by this isochronous resource manager node. In a configuration in which a bus manager does not exist on the bus, the isochronous resource manager may perform some functions of the bus manager such as power management and control of the cycle master.

The asynchronous (asynchronous) transfer mode will be described. FIG. 19 shows the time transition of asynchronous transfer. Subaction Gearup (subaction)
(gap) indicates an idle state of the bus. A node desiring to transfer determines that the bus can be used when the idle time reaches a fixed value, and requests a bus use right. The node permitted to use the bus in the arbitration sends data to the bus in a predetermined packet format. The node that has received the data returns a response code ack indicating the reception result of the transferred data after a short gap (ack gap) and returns a response or sends a response packet. This completes one unit of data transfer. The acknowledgment return code ack is made up of 4-bit information and a 4-bit checksum, and is used to notify the transmission source node of information indicating any of a success, a busy state, and a pending state.

FIG. 20 shows a packet format of the asynchronous transfer. The packet includes a header section, a data section, and data CRC for error correction. As shown in FIG. 20, the header section includes a destination node ID, a source node ID, a transfer data length, various codes, and the like.

Asynchronous transfer is one-to-one data transfer from one node to another node. Although the packet output from the transfer source node reaches each node in the network, each node ignores data other than its own. As a result, the data is taken in only one destination node.

The isochronous (synchronous) transfer mode will be described. The isochronous transfer mode is IEEE1394
It can be said that this is the biggest feature of the serial bus. The isochronous transfer mode is particularly suitable for transferring data that requires real-time transfer, such as video data and audio data. While the asynchronous transfer mode is a one-to-one data transfer, the isochronous transfer mode can transfer data from one transfer source node to all other nodes by using a broadcast function.

FIG. 21 shows a temporal transition in the isochronous transfer. The isochronous transfer is executed on the bus at regular intervals. This time interval is called an isochronous cycle. Isochronous cycle time is 125
μs. The cycle start packet indicates the start timing of each cycle and adjusts the time of each node. It is the cycle master that transmits the cycle start packet. After a predetermined idle period (subaction gap) has elapsed after the end of the transfer in the previous cycle, a cycle start packet indicating the start of the cycle. Send The time interval between the cycle start packet and the next cycle start packet is 125 μs.

As shown in FIG. 21 as channel A, channel B and channel C, a plurality of packets can be distinguished and transferred in one cycle by giving different channel IDs to each packet. Thereby, data can be transferred in real time between nodes of different combinations at the same time.
Each node takes in only the data of the channel ID desired by itself. The channel ID does not represent a destination address, but merely gives a logical number to data. Thus, such a packet is broadcast from one source node to all other nodes.

Prior to the packet transmission in the isochronous transfer, the arbitration of the right to use the bus is performed as in the case of the asynchronous transfer. However, since the isochronous transfer is not one-to-one communication like the asynchronous transfer, there is no acknowledgment reply code ack in the isochronous transfer.

The isochronous gap is shown in FIG.
o gap indicates an idle period necessary for recognizing that the bus is idle before performing isochronous transfer. A node desiring isochronous transfer determines that the bus is free after this idle period, and outputs a bus use right request signal.

FIG. 22 shows a packet format of the isochronous transfer. The packet includes a header portion, a data portion, and data CRC for error correction. The header part is
As shown in FIG. 22, it has a transfer data length, a channel number, other various codes, and an error correction header CRC.

The bus cycle of the IEEE 1394 serial bus will be described. On the IEEE 1394 serial bus, isochronous transfer and asynchronous transfer can coexist. FIG. 23 shows a temporal transition of the transfer state on the bus when the isochronous transfer and the asynchronous transfer are mixed.

After the cycle start packet, the gap length in the idle period required to start the isochronous transfer (isochronous gap) is determined by the gap length in the idle period required to start the asynchronous transfer (subaction gap). In this case, the isochronous transfer is performed prior to the asynchronous transfer. This enables real-time transfer of image data or audio data by asynchronous transfer.

In the general bus cycle shown in FIG. 23, at the start of cycle #m, the cycle start
Packets are transferred from the cycle master to each node. As a result, the time is adjusted at each node. A node that intends to transfer data isochronously waits for a predetermined idle period (isochronous gap), requests and acquires the right to use the bus, and then transmits a packet onto the bus. In FIG. 23, a channel e, a channel s, and a channel k are sequentially transferred in an isochronous manner. These three
After repeating the arbitration and the packet transfer for the channel, that is, when all the isochronous transfers in the cycle #m are completed, the asynchronous transfer becomes possible.

A node desiring asynchronous transfer is
After waiting for the idle time to reach a time corresponding to a subaction gap in which asynchronous transfer is possible, a right to use the bus is requested to the root. However, after the completion of the isochronous transfer, the next cycle start packet (cyc
Asynchronous transfer is possible only when a sub-action gap for activating the asynchronous transfer can be entered before the time until le sync). In the cycle #m shown in FIG. 23, isochronous transfer for three channels and then asynchronous transfer (including ack) for two packets are executed. After the second asynchronous packet, a timing (cycle sync) at which the cycle # (m + 1) is to be started is reached, so that the transfer in the cycle #m ends here.

However, when the next cycle start packet CSP is reached during the asynchronous transfer or the isochronous transfer operation, the cycle master does not forcibly interrupt the transfer and sets an idle period after the transfer is completed. After waiting, a cycle start packet for the next cycle is output. In the next cycle, the start of the cycle is delayed,
Make the cycle end earlier. That is, one cycle is 12
If it lasts for 5 μs or more, the next cycle is shortened accordingly by 125 μs. In this way, IEEE13
The cycle time of the 94 bus can be exceeded or reduced on the basis of 125 μs. The isochronous transfer is always performed if necessary every cycle to maintain the real-time transfer. However, the asynchronous transfer may be transferred to the next and subsequent cycles due to the shortened cycle time. A cycle master manages the cycles on the bus, including this type of delay information.

FIG. 1 is a block diagram showing a schematic configuration of an embodiment of the present invention. The vehicle 10 checks the ID and password of the source device added to the received data to permit data communication with the antenna 12 for wireless communication, the wireless transmitting / receiving circuit 14, and a specific wireless device. A security circuit 16 for adding the ID and password of the own device to the data to be transmitted, and a wireless / IEEE1394
It comprises a conversion circuit 18 and an AV device 22 connected to the wireless / IEEE 1394 conversion circuit 18 via an IEEE 1394 serial bus 20. In FIG. 1, the AV device 22 includes a tuner amplifier 24, a CD player 26, a car navigation system 28, a monitor 30, and a storage device 32 including a hard disk and a solid-state memory. These are also connected by an IEEE 1394 serial bus 34. Data can be exchanged with each other. Wireless / IEEE
The function of the E1394 conversion circuit 18 is as follows.
It may be incorporated within.

At present, regarding the networking of electric devices in a car, a data transmission system using an optical fiber is being studied by a car maker mainly from the viewpoint of weight reduction and improvement of noise resistance performance. The invention does not exclude the use of such data transmission media and data transmission systems.

On the other hand, an antenna 42 for wireless communication, a wireless transmitting / receiving circuit 44, a security circuit 1
6, security circuit 46, wireless / IEEE13
94 conversion circuit 48, computer 50, hard disk 52, DVD player 54, CD player 56, server 58 for recording and holding various data, digital VTR device 60, and TV monitor device 62.
The 394 conversion circuit 48, the computer 50, the hard disk 52, the DVD player 54, the CD player 56, the server 58, the digital VTR device 60, and the TV monitor device 62 are connected by an IEEE 1394 serial bus 64, and can mutually transmit and receive data. Wireless / IEEE13
The function of the 94 conversion circuit 48 may be incorporated in the wireless transmission / reception circuit 44 in some cases.

The basic operation of the equipment in the automobile 10 will be briefly described. The tuner amplifier 24 amplifies the audio output of the radio tuner and the audio output of the CD player 26 and supplies the amplified audio output to a speaker (not shown). Navigation system 2
8, an isochronous transfer of a map image or the like of the current position based on GPS data from a built-in GPS antenna to the monitor device 30, and the monitor device 30 displays the received image information on the screen. In addition, the navigation system 28
Can read the required map information from the CD-ROM loaded in the CD player 26. Storage device 3
2 is music information, image information accompanying car navigation,
And / or user specific data or the like can be stored.

By connecting these devices with an IEEE 1394 serial bus, connection of the devices is simplified, versatility in information exchange and the like is improved, and an integrated in-vehicle AV system can be constructed. Further, various data can be transmitted between devices at high speed. Stream data such as audio data and image data is transferred to each device in an isochronous transfer mode, and other control data and data are transferred to necessary devices in an asynchronous transfer mode.

Further, from the AV system 22 to the automobile 10
Data to be transmitted outside, for example, to any device at home 40 is transmitted to the wireless / IEEE1394 conversion circuit 18.
The wireless / IEEE1394 conversion circuit 18 converts data from the AV system 22 into data in a wireless communication format and supplies the data to the wireless transmission / reception circuit 14. The wireless transmission / reception circuit 14
In cooperation with the security circuit 16, the data from the conversion circuit 18 is added with the ID and password of the own device, and the data is wirelessly transmitted from the antenna 12.

Conversely, when data from the outside is received by the antenna 12, the radio transmission / reception circuit 14 operates in cooperation with the security circuit 16 to operate the I / O added to the reception data.
Based on D and the password, it is checked whether the data is from a partner to whom data communication is permitted. If the data is permitted, a permission signal is sent to the transmission / reception circuit 14 and the received data is output to the conversion circuit 18.

The basic operation of the devices in home 40 will be briefly described. Each of the devices 48 to 62 connected by the IEEE 1394 serial bus 64 can transmit and receive data bidirectionally.
For example, the computer 50 controls the operation of each of the devices 48, 52 to 62, and the data from the digital VTR device 60 or the CD player 56 can be transferred to the computer 50, the hard disk 52, and / or the server 58.
Furthermore, the reproduced video data from the digital VTR device 60 and the DVD player 54 can be transferred to the TV monitor 62 to display the image. These are all IE
It is well known as a method of using the EE1394 serial bus.

That is, by using the IEEE 1394 serial bus, connection of each device is simplified, versatility in information exchange and the like is improved, and an integrated home network can be constructed. Further, various data can be transmitted between devices at high speed. Stream data such as audio data and image data is transferred to each device in an isochronous transfer mode, and other control data and data are transferred to necessary devices in an asynchronous transfer mode.

For wireless data communication with the outside,
The functions and operations of the IEEE 1394 conversion circuit 48, the wireless transmission / reception circuit 44, and the security circuit 46 are basically the same as those of the wireless / IEEE 1394 conversion circuit 18, the wireless transmission / reception circuit 14, and the security circuit 16 in the vehicle 10 that are permitted communication partners. May be different, but are basically the same.

The wireless communication by the wireless transmission / reception circuits 14 and 44 uses a spread spectrum system. FIG. 2 is a schematic configuration block diagram of a spread spectrum wireless transmitter, and FIG. 3 is a schematic configuration block diagram of a corresponding wireless receiver.

First, the configuration and operation of the wireless transmitter shown in FIG. 2 will be described. Data to be transmitted is input to the serial / parallel converter 70. The serial / parallel converter 70 parallelizes the input data into n channels and supplies the data to multipliers 72-1 to 72-n. The discrete code generator 74 generates n discrete codes PN1 to PN0 and applies them to the multipliers 72-1 to 72-n. Multiplier 7
2-1 to 72-n multiply both inputs, and the adder 76 adds the multiplication results of the multipliers 72-1 to 72-n. The output of the adder 76 corresponds to a data signal spread to n channels. The RF conversion circuit 78 converts the baseband broadband spread signal output from the adder 76 into a radio frequency signal having an appropriate center frequency, and emits it from the antenna 80 to the air.

The radio receiver shown in FIG. 3 will be described. The radio signal in the air is supplied to the RF converter 84 by the antenna 82. The RF converter 84 appropriately filters and amplifies the signal from the antenna 82 and converts the signal into an intermediate frequency signal. The output of the RF converter 84 is distributed to n parallel channels. In each channel, correlators 86-1 to 86-8
6-n is the output of the RF converter 84 and the discrete code generator 9
By detecting a correlation with the spreading code of the corresponding channel from 0-1 to 90-n, the signal of the corresponding channel is restored. The synchronization circuits 88-1 to 88-n are provided with correlators 86-1 to 86-1.
The discrete code generators 90-1 to 90-n generate signals synchronized with the correlation result output of 86-n.
In synchronization with the output of 88-n, a discrete code of the corresponding channel is generated and supplied to correlators 86-1 to 86-n.

The demodulators 92-1 to 92-n include a correlator 86
Data is demodulated from the output signals of -1 to 86-n. The parallel / serial converter 94 serializes the output data of the demodulators 92-1 to 92-n to restore the received data.

The radio communication system is not limited to the above spread spectrum system. For example, a wireless communication system that conforms to a protocol in wireless communication according to the IEEE 1394 standard may be adopted, or another wireless communication system may be PI
The AFS method and the IrDA method are also possible. Needless to say, it is preferable that the wireless communication system has a transmission rate that does not hinder transmission of audio data and video data.

As an example of actual use, an operation of transmitting music data or data including map information for car navigation from the CD player 56 in the home network to the storage device 32 in the automobile 10 will be described. . FIG. 4 shows a flowchart of the operation.

The necessary devices connected to the IEEE 1394 network in the home are turned on and in a standby state (S51).
It is assumed that the necessary devices connected to the E1394 network have been turned on and are in a standby state including ID information and capable of wireless reception (S61).

The wireless transmission / reception circuit 44 transmits the set ID information to establish a wireless communication path (S5).
2). Unless the system is turned off (S64), the wireless transmission / reception circuit 14 of the automobile 10 waits for reception of ID (S6) until the ID information is received from the home 40 (S64).
2). Upon receiving the ID information (S62), the wireless transmission / reception circuit 14 transmits response information and guidance for inputting a password to the wireless transmission / reception circuit 14 (S63).

When receiving the response information from the car 10 (S53), the wireless transmission / reception circuit 44 in the home 40 prompts the user to enter the password #, and transmits the inputted password to the car 10 (S54). If the response information is not received within a predetermined period after transmitting the ID information (S
53) Since the radio signal does not reach the automobile 10 or the system in the automobile 10 is down, the processing is terminated.

The wireless transmission / reception circuit 14 and the security circuit 16 of the automobile 10 confirm whether the received password is correct (S65). If the password is not correct, the process ends. If your password is incorrect,
The password input may be tried a certain number of times.

When the password is confirmed (S65), the information such as the connection status of each device in the vehicle 10 and the communicable devices is stored in the IEEE 1394 bus topology and connected device information established in the vehicle's IEEE 1394 network. The device information is wirelessly transmitted from the wireless transmission / reception circuit 14 (S66).

When the system in the home 40 receives the device information from the car 10, the system in the home 40
Initially, necessary conditions for transferring data from 6 to the storage device 32 of the vehicle 10 are initialized. Specifically, based on the device configuration of the partner network and information related to it,
Which device of the partner network can transmit data, and the transmission procedure and command configuration at that time are set. The network of each device in the home 40 and the network of each device in the car 10 are two wireless / IE
By connecting via the IEEE 1394 conversion circuits 18 and 48 and the wireless communication means, it looks as if both networks constitute one integrated IEEE 1394 network as a whole.

The CD data to be transmitted to the storage device 32 of the automobile 10 is read out by the CD player 56,
The data is supplied to the IEEE 1394 conversion circuit 48. Conversion circuit 4
8 converts the data from the CD player 56 into a format suitable for a wireless mode without changing the basic contents, and supplies the data to the wireless transmitting / receiving circuit 44. Wireless transmission / reception circuit 4
4 adds a command instructing transfer to the storage device 32 of the automobile 10 as the transmission destination to the data from the conversion circuit 48, and wirelessly transmits the data to the automobile 10 (S56).

On the automobile 10 side, the wireless transmission / reception circuit 14 receives data from the home 40 and also reads information on the transmission destination device from the additional information. The wireless / IEEE1394 conversion circuit 18 converts the CD data, which is the data body of the received data, into I / O data.
The format is returned to the IEEE 1394 format, and the data is transmitted to the device specified by the information of the transmission destination device, that is, the storage device 32.
The data is output on the E1394 network (S67). The storage device 32 captures and stores CD data on the IEEE 1394 network (S68).

Until an instruction to stop the data output operation is input to the CD player 56 (S57), the reproduction output and transmission of the CD data, and the reception and storage in the automobile 10 are continuously executed. When the CD player 56 stops (S
57), the wireless transmission / reception circuit 44 in the home 40
An end signal is transmitted to the wireless transmission / reception circuit 14 of No. 0 (S58). Upon receiving the end signal, the wireless transmission / reception circuit 14 of the automobile 10 stops the storage operation of the storage device 32,
The wireless communication with the home 40 is released (S69).

Next, a second embodiment of the present invention will be described. For example,
As shown in FIG. 5, it is assumed that an in-vehicle camera 110 for photographing the front is installed in the automobile 10a. FIG.
FIG. 2A is a schematic block diagram showing the configuration of FIG. The same components as those included in the automobile 10 of FIG. 1 are denoted by the same reference numerals.
In FIG. 6, a vehicle-mounted camera 110, a traveling-time information storage device 112 that stores image information from the vehicle-mounted camera 110 and momentary traveling information, a drive system 114 including an engine of the automobile 10a, a battery and an electrically driven air conditioner, and the like Controller 1 that comprehensively controls each part of the automobile 10a including the electric system 116, the drive system 114, and the electric system 116
18, and a driving information generating means 120 for generating various driving information such as speed as driving information is newly provided. In-vehicle camera 110, traveling information storage device 11
2. The drive system 114, the electric system 116, and the car controller 118 are connected to an IEEE 1394 network, and the traveling information generating means 120 is connected to the car controller 118.

In the configuration shown in FIG. 6, among the devices connected to the IEEE 1394 bus, a tuner amplifier 24, a CD player 26, a navigation system 28, a monitor 3
0, the storage device 32, the in-vehicle camera 110, and the traveling information storage device 112 are grouped as an AV device group 122, and a drive system 114, an electrical system 116, and a car controller 118 are provided.
Are put together as an automobile unit 124. IEEE139
The four bus connection forms a network in which all the devices of the vehicle are integrated. It becomes easy to transmit the vehicle-specific information in the vehicle unit 124 to any device in the AV equipment group 122 and to wirelessly transmit the information to the outside of the vehicle 10a. That is, as described in the embodiment shown in FIG. 1, various data can be mutually transmitted between any device in the car 10a and any device in the home 40. In particular,
By transmitting control information from a device in the home network, for example, a PC to an automobile AV device or a car controller, an air conditioning switch, various switches,
And, it can be controlled while staying at home, such as an idling start command.

In addition, it is also possible to download image data photographed by the on-vehicle camera 110 and data stored in the traveling information storage device 112 to a server outside the vehicle. Taking the case of transmitting to the server 58 at home 40 as an example,
The operation will be briefly described.

In-vehicle camera 1 for photographing the front view while traveling
The ten photographed image data are transferred in real time on the IEEE 1394 bus by isochronous transfer, and the traveling information storage device 112 records the image data. In parallel with this, the traveling information generating means 120 obtains information from the speed, the parameters of each part of the vehicle, the time information, the outside temperature, the weather, the driving system 114, the electric system 116, and various sensor outputs. And collectively generate running time information
The car controller 118 transmits the traveling information to the IEEE
Via the 1394 bus, isochronous or synchronous transfer to the traveling information storage device 112 is performed so that the photographed image data of the vehicle-mounted camera 110 is linked and stored in the traveling information storage device 112 without time delay. The information storage device 112 stores the photographed image data of the vehicle-mounted camera 110 and the traveling information in a mutually linked manner.

The data composed of the image information and the traveling information stored in the traveling information storage device 112 as described above is as follows:
At an appropriate timing, for example, when the car is stopped in a parking lot, the data can be wirelessly transmitted to the server 58 of the house 40. The wireless transmission includes input of ID information and a password as security. The operation is performed by reversing the transmission side and the reception side in the flowchart shown in FIG. 4 and converting the CD data into travel information data including image data. It is the same as replacing.

[0106]

As can be easily understood from the above description, according to the present invention, the control of each AV device in the automobile and the simple operation of each section of the automobile can be performed by utilizing the radio to perform the operations outside the automobile. It can be done from another device. More specifically, by mounting a recording medium in a car, transmitting music data from a CD player outside the car before departure, and recording the data on a recording medium in the car, the user can easily select a desired music while driving. Can be played. Further, it is also possible to easily realize transmission of the image data of the in-vehicle camera recorded during traveling from the recording medium in the vehicle to the server at home. Furthermore, it is possible to control the equipment in the car while staying at home. Misuse can be prevented by checking the security of the ID and the password when using the wireless communication.

[Brief description of the drawings]

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

FIG. 2 is a schematic configuration block diagram of a spread spectrum wireless transmitter.

FIG. 3 is a schematic configuration block diagram of a spread spectrum wireless receiver.

FIG. 4 is an operation flowchart of the first embodiment.

FIG. 5 is a diagram showing a state of installation of a vehicle-mounted camera 110;

FIG. 6 is another device configuration diagram of an automobile.

FIG. 7 is an example of a network system configured by an IEEE 1394 serial bus.

FIG. 8 is a schematic configuration block diagram of an IEEE1394 interface.

FIG. 9 is a schematic diagram of an address space in an IEEE 1394 serial bus.

FIG. 10 is a sectional view of an IEEE 1394 serial bus cable.

FIG. 11 is a timing chart of a DS-Link encoding method adopted in the IEEE 1394 serial bus.

FIG. 12 is a schematic diagram of a network configuration of an IEEE 1394 serial bus.

FIG. 13 is a flowchart of a series of bus operations from the occurrence of a bus reset until the node ID is determined and data transfer can be performed.

FIG. 14 is a detailed flowchart of a process from bus reset to route determination.

FIG. 15 is a flowchart of a procedure from the determination of a route to the end of ID setting.

FIG. 16 is an explanatory diagram of a transmission path of a bus use right request signal.

FIG. 17 is an explanatory diagram of a transmission path of a bus use permission signal and a rejection signal.

FIG. 18 is a detailed flowchart of an arbitration process.

FIG. 19 is a schematic diagram of time transition of asynchronous transfer.

FIG. 20 is a schematic diagram of a packet format of asynchronous transfer.

FIG. 21 is a schematic diagram of time transition in isochronous transfer.

FIG. 22 is a schematic diagram of a packet format for isochronous transfer.

FIG. 23 is a schematic diagram of a time transition of a transfer state when isochronous transfer and asynchronous transfer are mixed.

[Explanation of symbols]

 10, 10a: Car 12: Antenna 14: Wireless transmission / reception circuit 16: Security circuit 18: Wireless / IEEE1394 conversion circuit 20: IEEE1394 serial bus 22: AV equipment 24: Tuner amplifier 26: CD player 28: Car navigation system 30: Monitor 32 : Storage device 34: IEEE 1394 serial bus 40: Home 42: Antenna 44: Wireless transmission / reception circuit 46: Security circuit 48: Wireless / IEEE 1394 conversion circuit 50: Computer 52: Hard disk 54: DVD player 56: CD player 58: Server 60: Digital VTR device 62: TV monitor device 64: IEEE 1394 serial bus 70: serial / parallel converter 72-1 to 72-n: multiplier 74: discrete code generator 76: adder 78: RF Conversion circuit 80: Antenna 82: Antenna 84: RF converter 86-1 to 86-n: Correlator 88-1 to 88-n: Synchronization circuit 90-1 to 90-n: Discrete code generator 92-1 to 92 -N: Demodulator 110: In-vehicle camera 112: Running information storage device 114: Drive system 116: Electric system 118: Car controller 120: Running information generating means 122: AV equipment group 124: Car unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/44 H04B 7/26 M 7/14 H // H04N 7/18 H04L 11/00 310C F term ( Reference) 5C025 DA01 DA07 DA08 5C054 AA01 AA05 CA04 CC03 EA01 EA03 EA07 GB04 HA30 5C064 AA01 AA06 AC04 AC07 AC08 AC18 AC20 5K033 BA06 BA08 DA19 DB12 5K067 AA34 AA35 AA41 BB03 BB04 BB21 DD17DD12

Claims (5)

[Claims] 1. A communication system mounted in an automobile, comprising: a data bus capable of transmitting AV data and control data, a plurality of AV devices connected to the data bus, and an external device connected to the data bus. Wireless communication means for mutually wirelessly communicating data with a device; and partner confirmation means for confirming a partner device and its user by a device ID and a password by wireless communication by the wireless communication unit. Communications system. 2. The communication system according to claim 1, wherein said data bus is an IEEE 1394 serial bus. 3. The communication system according to claim 1, wherein one or more devices related to the operation of the vehicle are connected to the data bus and can be controlled from outside the vehicle. 4. The communication system according to claim 1, wherein the AV device includes storage means for storing AV data transferred from outside the vehicle. 5. The communication system according to claim 1, wherein the AV device includes a vehicle-mounted camera, and a captured image of the vehicle-mounted camera can be transmitted outside the vehicle.