JP2002171260A - Communication method and communication system and communication terminal equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform communication by efficiently using a transmission band at the time of managing communication by using a topology map indicating inter-terminal communicating situations in a communication network system such as a radio network. SOLUTION: When prescribed communication terminal equipment manages communication in a communication network constituted of a plurality of communication terminal equipment, the plural kinds of communication systems are prepared, and the respective communication terminal equipment in the communication network presents values corresponding to the reception levels of signals received from all communication terminals equipment that can be communicated in the communication network, and allow the prescribed communication terminal equipment to perform the communication management based on the presented values. Then, the prescribed communication terminal equipment totals the values corresponding to the reception levels presented from the respective communication terminal equipment, and generates network topology information. Thus, it is possible to properly select the communication system at the time of communication in the respective communication terminal equipment based on the network topology information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication method, a communication system, and a communication terminal device applied to a communication network including a plurality of communication terminal devices, and more particularly, to a specific one communication terminal in a communication network. The present invention relates to a technique suitable for application to a device in which communication between communication terminal devices is executed in centralized management of devices.

[0002]

2. Description of the Related Art Conventionally, in a communication network for performing wireless communication or the like, in a situation where the network system is centrally managed by a single communication terminal, the network management communication terminal becomes a communication terminal in the network system. In some cases, the configuration is such that the network topology is managed. At this time, if the transmission method used in the network is a single, when managing the interconnection state of the communication terminals in the network system, that is, the topology map, by using only the reception quality, mainly the reception power, The management of the topology map was possible.

A terminal that centrally manages such a network system always secures an area for a topology map managed by itself at regular intervals, so that a topology map of terminals existing in the network is provided. Even when there is no change, the processing of notifying all terminals in the system has been performed.

[0004]

The above-described conventional processing is performed when the number of terminals existing in the network system does not change, and at the same time, the terminal in the network system communicates with other terminals in the network system. Even if there is no change in the interconnecting state, it is wasteful use of a limited resource, that is, allocating a certain bandwidth and notifying the topology map of the network system to all terminals in the system. In addition, when the conventional processing is used, in the network system, only the reception quality is used in order to manage the interconnection state for each terminal, so that a plurality of communication schemes ( Transmission method), there is a problem that cannot be dealt with. That is, in a situation where there are a plurality of communication methods, it is impossible to set a communication line uniquely and perform efficient and smooth communication in the processing using the conventional topology map.

As a result, even if two or more types of communication systems can be used between terminals in a network system, only one type of transmission system can be used when a management process using a topology map is performed. However, there has been a problem that flexible system management and operation in accordance with changes in the communication environment are restricted.

The present invention has been made in view of such a situation. When management is performed using a topology map in a communication network system of this type, communication based on the management reduces the transmission band efficiency. The purpose is to be able to use it well.

[0007]

SUMMARY OF THE INVENTION In order to solve this problem, the present invention provides a communication network in which a predetermined communication terminal manages communication in a communication network composed of a plurality of communication terminals. A plurality of types of communication methods are prepared as communication methods in the communication network, and values corresponding to the reception levels of signals from all communication terminal devices with which each communication terminal device in the communication network can communicate are presented in the communication network. The communication management is executed based on a value corresponding to the presented reception level.

According to the present invention, network topology information can be generated by a predetermined communication terminal device summing up a value corresponding to a reception level presented from each communication terminal device. Based on the topology information, it is possible to appropriately select a communication method at the time of communication in each communication terminal device.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described.
This will be described with reference to the accompanying drawings.

In this example, for example, IEEE (The In
Institute of Electrical and Electronics Engineers)
The transmission structure of the 1394 system is applied to a wireless communication network that realizes a so-called wireless 1394 system realized by a wireless communication network. In the case of the wireless 1394 system, in a network system having a plurality of communication terminal devices, the network is centrally managed by one specific communication terminal device. Hereinafter, the communication terminal device to be managed is referred to as a management communication terminal device. Here, the maximum number of communication terminal devices (stations) in one network is set to 16 stations.

[0011] As a management form here, it is assumed that a management communication terminal device is located substantially at the center of the network and that the management communication terminal device directly controls each communication terminal device in the network. However, the data transfer process itself is not necessarily limited to the star type, and a so-called mesh type network is also possible.

FIG. 1 is a diagram showing a configuration example of a wireless communication network of the present embodiment. Here, the wireless communication network 100 includes four wireless communication terminal devices 110, 120, 130, and 140. Here, ID numbers # 1, # 2, # 3, and # 4 for identification are individually assigned to the four wireless communication terminal devices 110 to 140.

In the example of FIG. 1, the wireless communication terminal device 110 having ID number # 1 is a communication terminal connected (or built-in) to a set-top box (STB) for receiving and decoding a broadcast signal such as a satellite broadcast. is there. The wireless communication terminal device 120 with the ID number # 2 is a communication terminal connected (or built-in) to the television receiver. ID number # 3
The wireless communication terminal device 130 is a communication terminal connected (or built-in) to a game device for executing a so-called video game (video game) on a television receiver or the like. The wireless communication terminal device 140 of ID number # 4 is a communication terminal connected (or built-in) to a video deck that records and reproduces video signals and audio signals.

Here, the wireless communication terminal device 110 connected to the set-top box is a management communication terminal device for centrally managing communication in the network system, and each communication device in the network is controlled by the management communication terminal device. Wireless communication is performed between the terminals 110 to 140. The wireless communication terminal device 110, which is the management communication terminal device, performs a process of registering the other communication terminal devices 120, 130, and 140 with a terminal in the network according to a predetermined registration procedure.

FIG. 2 shows a configuration example of each wireless communication terminal device. Antenna 1 for wireless transmission and reception
Is connected to the wireless processing unit 2, and the signal received by the antenna 1 is subjected to reception processing by the wireless processing unit 2 to generate an intermediate frequency signal or a baseband signal, and the obtained signal is supplied to the data conversion unit 3. Then, the data is converted into data in a required format, and the required data in the data is extracted, and the extracted data is supplied to the interface unit 4. An external device 8 is connected to the interface unit 4 via a serial bus line 7 of a predetermined format, and transmits received data to the device 8.

Further, data supplied from the device 8 via the serial bus line 7 is received by the interface unit 4 and data obtained by the interface unit 4 is
The data conversion unit 3 converts the data into data in a format for wireless transmission,
The converted data is supplied to the wireless processing unit 2. The wireless processing unit 2 performs processing for transmission and causes the connected antenna 1 to wirelessly transmit. Note that the device 8 corresponds to the STB, the television receiver, the game device, and the VCR shown in FIG.

A relatively high frequency band such as a 5 GHz band is used as a frequency used for transmitting and receiving a radio signal in the radio processing unit 2. The transmission output is set to, for example, a relatively weak output. For example, when the transmission output is used indoors, the output is set to such an extent that wireless transmission over a relatively short distance from several meters to several tens of meters can be performed. Here, in this example, a plurality of types of modulation schemes can be selectively used as a modulation scheme of a signal to be wirelessly transmitted by the wireless processing unit 2. As a specific example, for example, as shown in the list in FIG. 7, the rate 1/2 and the rate 3/4 of the BPSK modulation scheme, the rate 1/2 and the rate 3/4 of the QPSK modulation scheme, The configuration is such that ten types of modulation methods of 1/2, rate 3/4 and rate 7/8, and rate 1/2, rate 3/4 and rate 7/8 of the 64QAM modulation method can be selected. Also, the demodulation of the received signal is configured to be able to demodulate any signal of the above-described 10 types of modulation schemes. The selection of the modulation method is executed under the control of the control unit 5. Note that the modulation method and rate may be limited depending on the data handled by the connected device 8.

The serial bus line 7 connecting the main body of the wireless communication terminal and the device 8 is, for example, an IEEE 1
It is a general-purpose bus line capable of high-speed transmission, such as a 394 bus. Various devices such as a video device, an audio device, and a computer device can be connected to the device 8 connected by the bus line 7, and the device 8 handles video data, audio data, text data, program data, and the like handled by these devices. Various data is wirelessly transmitted via the wireless transmission device.

The transmission and reception processing in the wireless processing unit 2, the conversion processing in the data conversion unit 3, and the interface processing in the interface unit 4 of this wireless communication terminal device are performed by a control unit composed of a microcomputer or the like. 5 is executed. The control unit 5 has an internal memory 6 in which a control program and the like are stored. In this case, if the signal received by the wireless processing unit 2 is a signal for controlling communication, the received signal is supplied to the control unit 5 via the data conversion unit 3, and the control unit 5 receives the received signal. Each part is set to the state indicated by the control signal. Also, a control signal transmitted from the control unit 5 to another transmission device is supplied from the control unit 5 to the wireless processing unit 2 via the data conversion unit 3 and wirelessly transmitted.

Next, a frame format defined for performing wireless communication in the network system of the present embodiment is shown below.
This will be described with reference to FIG. This frame configuration is set by the management communication terminal device, and a frame start signal is arranged at the head of one frame. Further, a station sync section is set in a predetermined section after the frame start signal. The use mode of the station sync section will be described later. Then, an arbitrary number of slots for isochronous communication (synchronous communication) are set in the band reservation area following the station sync section (8 in the example of FIG. 3).
Slots) and perform isochronous communication between arbitrary terminal devices in the network. This isochronous communication is mainly used when transmitting stream data such as video data and audio data while maintaining real-time properties. Note that the area of the bandwidth reservation area changes according to the number of slots set at that time. Further, a section for asynchronous communication (asynchronous communication) is set in a section after the band reservation area, and asynchronous communication is performed. This asynchronous communication is used to transmit various data that does not require real-time transmission. The transmission destination returns confirmation data (ACK) from the transmission destination for reliable transmission, and various control data is also transmitted. You.

The frame start signal and the signal in the station sync section are transmitted using, for example, the lowest transmission speed among a plurality of types of communication systems prepared in the network system of this embodiment.

As one of the data transmitted in the section for asynchronous communication, there is topology map information transmitted from the management communication terminal device 110 in this example. This topology map information is information summarizing the communication state when direct wireless communication is performed between each terminal device in the network, and is based on a signal transmitted from each communication terminal device in the network. The control unit in the device 110 creates the data and holds it in a memory (for example, the internal memory 6 in FIG. 2) connected to the control unit.

The topology map information held in the management communication terminal device 110 is used when each communication terminal device in the network wants to set up a communication line with another communication terminal device in the network and perform data transmission. The communication terminal device whose communication line is to be set is the management communication terminal device 1.
10 is requested to transmit the topology map information, and the management communication terminal apparatus 110 transmits the request based on the request.

As the transmission request of the topology map information, the transmission of the topology map information may be directly requested, but in the case of this example, the setting of the communication line to the management communication terminal device 110 is performed. Is equivalent to a request for transmission of topology map information. The communication line setting request here includes, for example, a request for allocating a packet (channel) for isochronous communication in order to transmit some stream data by isochronous communication.

FIG. 4 shows an example of a data structure when this topology map information is transmitted by asynchronous communication. In this example, the data is composed of 35 octets (1 octet is 8 bits) of data. 7 octets are used for the header, 24 octets are used for the payload which is the topology map information itself, and 1 octet is used for the error correction code.
The data is transmitted using octets.

Next, the data structure of the station sync section will be described. FIG. 5 shows an example of a data configuration of a station sync section. In FIG. 5, 4
Octets are shown in units. In the first four octets, there is a transmission from the management communication terminal, and the remaining sections are used to set sections for transmitting data from each communication terminal in the network. . Here, 1
This is an example in which data of four stations (that is, four communication terminal devices) can be transmitted using a unit station sync section. In this example, an eight octet section is assigned to each station. In the section assigned to each station, the assigned station (communication terminal apparatus) transmits data of the received electric field strength when the terminal apparatus receives a signal of each station in the network.

When the number of communication terminals in one network exceeds four, transmission is performed using a plurality of frame periods. For example, in the case of eight stations, the data of all the stations is transmitted using two frame periods, and ID #
Data # 1 to # 4 are transmitted, and data # 5 to # 8 are transmitted in the station sync section of the even frame.
In this example, since the network is composed of four stations, data from all stations is transmitted in one frame period.

FIG. 6 shows an example of data actually transmitted from each station. Using the eight octets assigned to one station, data of the received field strength of signals from terminal devices up to 16 stations existing in one network is transmitted. However, in the case of this example, since there are only four stations, the first two stations of the eight octet section allocated to each station are
Only the octet section (ie, the 16-bit section) is used, and 0 data is placed in the remaining sections.

The reception electric field strength of one station is indicated by a hexadecimal value indicated using four bits. That is, the received electric field strength here is a hexadecimal value of 0, 1, 2, ‥‥, 8, 9, a, b, c, d, e,
It is indicated by any value of f, and each value corresponds to the received electric field strength. In this example, the received electric field strength of a signal from each station existing in the network is shown in the order of the ID number of the station.

Here, the value 0 indicates that the corresponding station does not exist (or does not operate even if it does exist), and the values 1 to a are values corresponding to the received electric field strength. 1
Is the case where the received electric field strength is the lowest, and the value a is the case where the received electric field strength is the highest. The value f indicates that a signal from a station existing on the network cannot be received, and the value e indicates that the own station.

In the case of this example, the values 1 to a corresponding to the received electric field strength are values indicating a communication system suitable for receiving the received power at the received power. That is, in the case of this example, as shown in FIG.
/ 2 and rate 3/4, QPSK modulation scheme rate 1 /
2 and rate 3/4, rate 1/16 of 16QAM modulation scheme
2, rate 3/4 and rate 7/8, rate 1/2 of 64QAM modulation scheme, rate 3/4 and rate 1/8
0 types of modulation schemes can be selected by the communication terminal device. For these 10 selectable modulation schemes,
Values 1 to a corresponding to the received electric field strength are assigned in ascending order of transmission speed, and FIG. 7 shows the correspondence between the values and the modulation method (and rate). The values 1 to a corresponding to the received electric field strength are referred to as link status levels.

FIG. 8 shows an example of a received electric field strength and a modulation method suitable for use in the case of the received electric field strength. For example, a terminal apparatus receives a signal received from a specific terminal apparatus. Electric field strength (received power) is -50 dBm or more
When the transmission rate is within the range of -55 dBm, good transmission is possible by the 64QAM method, and any one of three types of transmission rates is set in the range according to the value of the received power. When the received power is in the range of −55 dBm to −60 dBm, good transmission is possible by the 16QAM method, and one of three types of transmission rates is further set in the range according to the value of the received power. The received power is -60 dB
When it is in the range of m to -65 dBm, good transmission is possible by the QPSK method, and one of two types of transmission rates is further set in the range according to the value of the received power. Further, when the reception power is in the range of -65 dBm to -70 dBm, good transmission is possible by the BPSK method, and one of two types of transmission rates is further set in the range according to the value of the reception power. The reception power is determined, for example, by receiving a signal in a station sync section in one frame.

In this manner, the data of the received electric field strength transmitted from each communication terminal device in the network is received by the radio processing unit in the management communication terminal device, and is aggregated as topology map information in the control unit. Keep it in memory.

Next, a process for starting wireless communication between any two communication terminal devices in the network will be described. FIG. 9 is a diagram illustrating a process at the transmitting station when performing wireless communication, and FIG. 10 is a diagram illustrating a process at the receiving station.

The processing at the transmitting station shown in FIG. 9 will be described. When the terminal is in the initial state 81, the terminal is registered in the management communication terminal device, and the terminal enters the idle state 82. For example, when it is desired to transmit some kind of stream data, a request for transmission of topology map information is made to the management communication terminal device, and the topology map information is received. Based on the received topology map information, a communication speed that is preferably set with the receiving-side terminal device is determined, and a link setting request packet is transmitted to the receiving-side terminal device by the communication method of the communication speed. The transmission is made and the transmission standby state 83 is set. In this transmission standby state, when a link setting request ACK signal responding to the request is returned, the state changes to the transmission enabled state 84.

When the transmission of the stream data is completed in the transmission enabled state 84, the idle state 82
Return to When the link setup request is rejected in the transmission standby state 83 or when the line state is poor, the state returns to the idle state 82. In the transmission standby state 83, if there is no reply within the specified time, the link setup request is transmitted again.

In the transmission standby state 83, when the number of times the link setup request is rejected exceeds the specified number, the processing is performed by the communication method in which the communication speed is at least one step lower than the communication method set at that time. The state shifts to the adjustment state 85 to be changed, the transmission processing of the link setting request ACK signal is performed by the communication method set in the adjustment state 85, and the link setting request ACK signal responding to the request is returned. become.

In the adjustment state 85, a link setting request AC
If the K signal is not returned, a communication method with a low communication speed is tried stepwise. If the link setting request ACK signal is not returned even if the slowest communication speed is set by performing this processing, the process returns to the idle state 82. Further, when a state occurs in which the network cannot receive the signal from the management communication terminal device in each state, the state returns to the initial state 81 as shown by a broken line in FIG.

Next, the processing in the terminal device on the receiving side will be described with reference to FIG.
Referring to FIG. 0, when the terminal is in the initial state 91, the terminal is registered in the management communication terminal device and becomes an idle state 92. When a link setting request packet is received in the idle state 92, the reception In the determination state 93, when the reception is possible, a link setting request ACK signal is returned, the process proceeds to the reception enabled state 94, the received data is processed, and when the reception is completed, the process returns to the idle state 92. In the reception determination state 93, when a line cannot be set up in the terminal, a link setting request NACK signal for rejecting the link setting request is transmitted, and the idle state 92
Return to Note that the link setting request ACK signal and the link setting request NACK signal that are returned in response to the link setting request may be transmitted by, for example, a communication method having the lowest communication speed.

By performing processing on the transmission side and the reception side in this way, the transmission speed at the start of communication is set well.

When the management communication terminal recognizes that the line setting at the communication speed set on the transmitting side based on the topology map information has not succeeded, the management map information stored in the management communication terminal corresponds to the corresponding topology map information. May be modified to topology map information indicating that a lower transmission rate is appropriate, as information on the terminal device to perform. The modification of the topology map information may be performed by a request from the communication terminal device on the transmission side where the line setting is not successful. That is, the communication terminal device that failed in line setting transmits a topology map update request packet as an asynchronous control packet to the management communication terminal device, and the management communication terminal device that has received the packet updates the topology map information. You may do it.

If the link setting request ACK signal can be received at one time at the communication speed set based on the topology map information, the link setting request signal that has been processed at least one step faster in communication speed from the transmitting side. May be transmitted to determine whether transmission at a higher speed is possible.

Further, in the above-described embodiment, the topology map information is created by simply determining the appropriate communication speed from the received power. However, the equipment (or the communication terminal) connected to each communication terminal device is created. It is also possible to create topology map information that determines the maximum transmission rate that can be handled by the device itself. For example, based on the correspondence between the reception power and the transmission scheme shown in FIGS. 7 and 8, a value corresponding to the optimum transmission rate is simply set. If there is a limit on the maximum transmission rate that can be input by the device connected to the device at the stage of creating the map, make the topology map information indicate a value corresponding to the maximum transmission rate. May be.

In the description so far, it is assumed that the prepared communication terminal device has been set to execute the above-described processing. That is, as shown in FIG. 11, for example, by configuring the system LSI 11 in the communication terminal apparatus 10 to execute the above-described processing, a communication terminal apparatus that executes the above-described processing is obtained. .

Further, a program for executing the above-described functions is stored in the semiconductor memory 12 in the communication terminal device 10 shown in FIG. 11, and a communication terminal device capable of performing the above-described processing is obtained. You may do it. The communication terminal device 10 includes an IEEE1394 bus terminal 13, a USB (Universal Serial Bus) terminal 1
4. By providing external interfaces such as a PCMCIA standard card insertion slot 15 and a telephone line jack 16, a program can be received via these external interfaces and installed in the semiconductor memory 12.

FIG. 12 shows an example of processing for downloading a program to the communication terminal device 10. The program is transmitted from the download site 20 to the communication terminal device 10 via any network 30 such as the Internet, or It is conceivable that the program is transmitted through a satellite line using the artificial satellite 40. Further, the program may be installed using some storage medium.

[0047]

According to the present invention, when a communication terminal that centrally manages a single communication network system attempts to secure a new band in this network system, for example, the bandwidth that can be allocated in the network is changed. It is determined whether or not there is, and if it is possible to allocate the band requested by the terminal to the communication terminal that desires the band allocation, it is possible to allocate the band, and it is possible to satisfy the band allocation request. If not,
A communication terminal that is centrally managed rejects the bandwidth allocation request, and in a communication network system, when realizing an application such as moving image transfer that requires real-time performance in a wireless communication network system, It has become possible to dynamically assign a certain band in the system to a communication terminal preferentially or exclusively.

Further, when the communication environment changes in a state where the band is reserved, the communication quality status between the communication terminals communicating using the reserved band is monitored at a fixed cycle or the like. When there is a remarkable change in the quality, the provision of means for dynamically changing the communication method for communication terminals that perform communication by performing bandwidth reservation makes it possible to prevent deterioration of communication quality. Was.

Further, the communication quality between terminals communicating with each other is constantly monitored, and the monitoring result is periodically reported to the management terminal of the network system, for example.
When the communication quality between terminals has been improved, it has become possible to transmit the communication method between the terminals at a higher modulation rate. As described above, the communication method between the terminals can be set to a higher modulation speed, so that the band, which is a limited resource, can be effectively used.

For example, when communication quality between specific communication terminals deteriorates due to a transient phenomenon, for example, 16QAM modulation is performed between the communication terminals in order to maintain a desired communication quality (for example, bit error rate). The desired communication quality can be maintained by reducing the modulation rate from the rate 1/2 of the scheme to the rate 1/2 of the QPSK modulation scheme.

As a result, smooth communication can be performed by maintaining the communication quality between the communication terminals, instead of sacrificing the bandwidth utilization between the communication terminals. Thereafter, when the communication quality between the specific communication terminals is improved, the modulation scheme that can be used to maintain the desired communication quality between the communication terminals is to change the modulation rate at a specific timing to the rate 1 / QPS modulation rate. By changing the rate from 2 to the rate 1/2 of the 16QAM modulation scheme, it is possible to effectively use the band.

Further, since the communication quality information between these communication terminals is uniquely managed by the communication terminal that centrally manages the network system and is constantly updated, any communication terminal in the network system is connected to the network system. Since it is not necessary to hold link information between other communication terminals in the communication terminal, it is possible to simplify the processing in the communication terminal, it is possible to reduce the amount of memory held by the communication terminal, The cost of the communication terminal can be reduced. Further, after a communication line is once set up and linked between a plurality of communication terminals, the centralized management terminal of the network system generates control traffic only at the time of link setting and performs communication actually. It is possible to manage communication terminals while reducing traffic in the network system by exchanging with and monitoring the communication in the network system.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an example of a communication network according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a communication terminal device according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating an example of a frame configuration according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram showing an example of a transmission packet according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram showing an example of a station sync packet according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram showing an example of data of each station in a station sync packet according to an embodiment of the present invention.

FIG. 7 is an explanatory diagram illustrating an example of a modulation scheme and a correspondence between a rate and a value according to an embodiment of the present invention.

FIG. 8 is an explanatory diagram illustrating an example of a relationship between received power and an encoding method according to an embodiment of the present invention.

FIG. 9 is an explanatory diagram showing a processing example in a transmitting station according to an embodiment of the present invention.

FIG. 10 is an explanatory diagram illustrating a processing example in a receiving station according to an embodiment of the present invention.

FIG. 11 is a perspective view showing an example of a device shape of a communication terminal device according to an embodiment of the present invention.

FIG. 12 is an explanatory diagram illustrating a configuration example connected to a communication terminal device according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Antenna, 2 ... Wireless processing part, 3 ... Data conversion part, 4
... Interface unit, 5 ... Control unit, 6 ... Internal memory,
7 serial bus, 8 connected devices, 10 communication terminal device, 11 system LSI, 12 semiconductor memory,
13 ... IEEE1394 bus terminal, 14 ... USB
Terminals 15: PCMCIA card slot 16: Telephone line jack 100: Network system 11,
0: set top box (STB), 120: television receiver, 130: game machine, 140: VCR

Claims (17)

[Claims] 1. A communication method in which communication in a communication network configured by a plurality of communication terminal devices is managed by a predetermined communication terminal device, wherein a plurality of types of communication systems are prepared as communication systems in the communication network. A communication method wherein a value corresponding to a reception level of a signal from all communication terminal devices that can communicate with each communication terminal device in the communication network is presented in the communication network. 2. The communication method according to claim 1, wherein the value corresponding to the reception level is a value indicating an optimal communication method among a plurality of prepared communication methods. 3. The communication method according to claim 1, wherein said predetermined communication terminal device managing said network topology information indicating a communication state in a communication network from a value corresponding to said presented reception level. A communication method for creating and holding network topology information and transmitting network topology information held by a request from an arbitrary communication terminal device. 4. The communication method according to claim 3, wherein when performing communication with an arbitrary communication terminal device in a communication network, the communication device requests transmission of the network topology information, and obtains the network topology obtained by the request. A communication method in which an appropriate one is selected from the plurality of prepared communication methods based on the information and an attempt is made to set up a communication line. 5. The communication method according to claim 4, wherein when an attempt to set up the communication line fails, the communication method is changed to a communication method having a lower transmission rate than the communication method selected at that time, and the communication line is re-established. Communication method to try setting. 6. The communication method according to claim 4, wherein when the setting of the communication line fails, the network topology information created by the predetermined communication terminal device is corrected. 7. In a communication system in which communication in a communication network composed of a plurality of communication terminal devices is executed under management of a predetermined communication terminal device, each communication terminal device in the communication network has a plurality of types of communication terminal devices. Communication means corresponding to the communication method; detection means for detecting a reception level of a signal from another communication terminal device in the communication network; and data corresponding to the reception level detected by the detection means are transmitted from the communication means. A communication system comprising a control unit. 8. The communication system according to claim 7, wherein the data corresponding to the reception level to be transmitted under the control of the control means is data indicating an optimal communication system among a plurality of prepared communication systems. Communication method. 9. The communication system according to claim 7, wherein said predetermined communication terminal device that manages communication judges data of a value corresponding to a reception level transmitted from each of said communication terminal devices, and Means for creating and holding network topology information indicating a communication state within the network, and communication for transmitting the network topology information created by the managing means to a communication terminal device in a communication network in response to a request from any communication terminal device A communication system comprising: 10. The communication system according to claim 9, wherein the control means included in each communication terminal device in the communication network sets the communication line with another communication terminal device in the communication network. A communication system for requesting transmission of network topology information held in a device, and performing control for selecting an optimal communication method by a communication unit based on the network topology information transmitted by the request. 11. The communication system according to claim 10, wherein the control means provided in each communication terminal device in the communication network, when the setting of the communication line fails, the communication method selected by the communication means at that time. A communication system that performs control to change to a communication method with a lower transmission rate and to try setting a communication line again. 12. The communication system according to claim 11, wherein said management means of said predetermined communication terminal device determines network topology information when determining that the setting of a communication line in each communication terminal device in the communication network has failed. Communication system. 13. A communication terminal device for performing communication with another communication terminal device in a communication network by managing a predetermined communication terminal device, comprising: a communication unit corresponding to a plurality of types of communication systems; A communication terminal device comprising: a detection unit that detects a reception level of a signal from another communication terminal device; and a control unit that causes the communication unit to transmit data corresponding to the reception level detected by the detection unit. 14. The communication terminal device according to claim 13, wherein the control unit requests a transmission of network topology information from the communication unit when setting a communication line with another communication terminal device in a communication network. And a communication terminal device that controls the communication means to select an optimal communication method based on the network topology information received by the communication means based on the request. 15. The communication terminal device according to claim 14, wherein said control means, when setting of said communication line fails,
A communication terminal device that performs control to change to a communication method having a lower transmission rate than the communication method selected by the communication means at that time and to try setting a communication line again. 16. A communication terminal device having a function of managing communication between communication terminal devices in a communication network in which each communication terminal device can set a plurality of communication methods, wherein the communication terminal device communicates with each communication terminal device in the communication network. Communication means for performing, from the signal received by the communication means, determine the reception status at each communication terminal device in the communication network, create and hold network topology information indicating the communication state in the communication network, A communication terminal device comprising: a management unit for transmitting the held network topology information from the communication unit in response to a request from another communication terminal device. 17. The communication terminal according to claim 16, wherein said management means corrects network topology information when determining that setting of a communication line in each communication terminal in the communication network has failed. apparatus.