JP3350007B2 - Frame error rate threshold variation control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame error rate threshold variation control method for varying a frame error rate threshold to an appropriate value according to a communication purpose.

[0002]

2. Description of the Related Art An example of a conventional communication channel switching method is described in Japanese Patent Application Laid-Open No. H11-150751. The channel switching device and the channel switching method described in this publication detect and compare a reception electric field strength and an interference wave reception electric field strength, and determine a D / U ratio which is a ratio of the reception electric field strength and the interference wave reception electric field strength. Calculated, and then FER (Fra
me Error Rate), D / U ratio and F
The communication channel is switched by predicting each value with reference to the history with the ER.

As shown in FIG. 1, a conventional control method includes a PHS network switch 10 and base stations 12-1 and 12-2.
And PHS mobile stations PS14-1 and 14-2.

A personal handyphone system (PH)
S) is a channel switching F in which the mobile station is notified from the base station.
It is effective to perform line monitoring based on the ER threshold and perform interference detection, and has a function of searching for a stable channel when an error rate exceeding a channel switching FER threshold is detected. In the channel switching, after detecting the occurrence of interference 20 as shown in FIG.
There is a case where a stable communication channel is selected and the communication channel switching 22 is performed between the mobile station and the base station 12-1. Alternatively, after detecting the occurrence of the interference 24, the channel switching 26 including the control channel to the other base station 12-2 is performed for the reason that the reception electric field strength between the mobile station 14-2 and the base station 12-1 is low. May be performed. In any case, this function is necessary to maintain a stable call.

[0005]

Problems to be Solved by the Invention Japanese Patent Application Laid-Open No. H11-1507
The channel switching device and the channel switching method described in Japanese Patent Publication No. 51 accurately grasp communication quality of a communication channel,
By performing accurate channel switching, it is possible to improve communication quality. However, the required call quality for voice communication and data communication is different. The communication quality required for voice communication can transmit information even if the voice is interrupted to some extent. In the case of data communication, it is necessary to retransmit.

In the conventional method, when the PHS is used not as a telephone but as a means of data communication, when the channel quality is lower than the channel switching FER threshold notified from the base station, the line quality is close to the threshold. In this case, retransmission frequently occurs due to a missing data frame, and the data transmission performance decreases.

That is, when performing data communication by dial-up using PHS, communication performance may be extremely deteriorated, and PIAFS (PHS Integer) may be used.
rnet Access Forum Standard
The data transmission is delayed by the retransmission control according to d), and as a result, TCP (Transmission Control P) is transmitted.
It has been known that retransmission and sequence reset of a protocol (protocol: transmission control protocol) occur. As a measure for improvement, a method in which channel switching is performed at an earlier stage than in the case of voice-based switching can be considered.
For that purpose, it is appropriate to reduce the FER threshold value and execute the early channel switching.

An object of the present invention is to provide an FER according to a communication purpose.
An object of the present invention is to provide a method of controlling a change in a FER threshold value according to a purpose of use, which improves a communication quality of data communication by changing a threshold value to an appropriate value.

[0009]

According to the present invention, there is provided a frame error rate threshold variation control method, comprising: a mobile station terminal capable of performing data communication in a mobile communication network; And a base station that transmits and receives the data communication to and from another terminal via the mobile communication network. When performing the data communication, when the call quality is reduced, the control of lowering the frame error rate threshold value, which is the error rate of the data frame, by switching the communication channel being used or by switching the signal to another base station, is performed. To get started,
A frame error rate threshold, which is a reference value in the mobile station terminal and the base station, is reduced.

The base station obtains a communication type included in a call setting message from the mobile station terminal, switches a communication channel in use when the communication is data communication, and switches to another base station. In order to reduce the frame error rate threshold, which is signal information for starting switching control, to reduce the frame error rate threshold, and to notify the mobile station terminal of the reduced value to reduce the frame error rate threshold in a definition information response message. It is characterized by.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of an embodiment of the present invention will be described in detail with reference to FIG. FIG. 2 is a diagram showing the configuration of the embodiment of the present invention.

As shown in FIG. 2, the method for controlling the fluctuation of the FER threshold value of the present invention uses TCP / IP to communicate with a machine finally connected to the Internet via a PHS mobile terminal using a Note-PC. Assume the configuration.

The configuration of the present embodiment includes the Internet, a gateway device, an ISDN terminal adapter, an ISDN
A PHS network exchange 10 connected to a network and exchanging data communication with an ISDN network and a plurality of base stations; and a PHS housed in the PHS network exchange 10 for transmitting and receiving data communication with a terminal station.
Base station 14 and TCP / IP, PPP (Pointto
No. which has a communication function by remote access system (RAS) using Point Protocol)
te-PC16. Also, the PHS mobile station PS1
4, the PHS base station CS12 has an interface device connectable to the Note-PC 16.

The call setup message includes information transfer capability indicating information such as voice, unrestricted digital, and 3.1 kHz audio, and telephone, G2 / 3 facsimile, and G4 (class 1).
It has a higher layer characteristic identification indicating information such as facsimile and other information. Further, the information element of the information transfer capability is control information of the FER threshold value for data communication. The definition information response has area information including a channel switching FER threshold. The FER (frame error rate) threshold is a value of an error rate (error rate) of a data frame of a received signal of data communication, voice communication, and other communication, and is a value at which a base station is switched based on this value. In addition, the present invention provides an
In order to perform control for lowering the R threshold, the FER threshold reference value of the terminal and the base station is reduced to control communication channel switching of the same base station or communication channel switching to another base station. is there.

Next, the operation of the embodiment of the present invention will be described in detail with reference to FIG. FIG. 3 is a diagram showing the operation of the embodiment of the present invention.

The PS 14 is connected to the CS 1 to perform a calling control. FIG. 3 shows a part of the sequence and a part of the information elements included in the message. The PS 14 transmits a call setup message 101 including an information element of the information transfer capability 111 to the CS 12. Upon receiving a response, the call destination CS 12 transmits a call setting reception 102 to the PS 14. PS
14 transmits the definition information request 103 to the CS 12. C
In step S12, a definition information response 104 including area information 141 (channel switching FER threshold) is transmitted to the PS 14 in response to the definition information request 103 from the PS 14.

Here, the definition information request 103 is always transmitted when the PS 14 does not hold the definition information of the area, but does not need to be transmitted when the definition information response 104 has already been received. In But,
This is an essential message in the present invention. That is, PS1
Performs data communication within the same area and
4 already has the information of definition information request 103
Is not transmitted, but the information of the channel switching FER threshold included in the definition information request 104 is required. That is, in response to the definition information request 103, the PS 14 acquires information such as the channel switching FER threshold from the CS 12.

The PHS base station CS12 refers to the information element of the information transfer capability 111 included in the call setting 101 of the PS 14, and recognizes whether the purpose of use is "telephone" or "data communication". When the base station CS12 determines the channel switching FER threshold, which is one of the information elements of the definition information response message 104, if the information transfer capability is "voice" or "3.1 kHz audio", the base station CS12 conventionally uses the information in the area. If the information transfer capability is "unrestricted digital", a value lower than the FER threshold conventionally used in the area is calculated and given.

Note that line monitoring, interference detection, and channel switching control during communication between the mobile station PS14 and the base station CS12 follow ordinary methods. Also, more detailed F
The calculation of the ER threshold can be performed based on the higher layer characteristic identification 112, which is one of the information elements included in the call setup message 101 shown in FIG.

Further, in calculating the FER threshold, a mechanism may be considered in which the FER threshold is not determined by the base station, but is determined independently by the mobile station. The base station realizes the mobile station-initiated communication channel switching by notifying the mobile station of the existing FER threshold and performing the FER threshold minus α notified according to the communication purpose.

[0021]

The FER threshold fluctuation control method of the present invention is
When the mobile station is performing data communication, it is possible to switch the communication channel by using an FER lower than the conventional FER threshold, and to reduce data transmission delay, communication performance, or communication channel disconnection due to frequent retransmission of data frames. , And the data communication performance can be kept high.

[Brief description of the drawings]

FIG. 1 is a diagram showing a conventional configuration.

FIG. 2 is a diagram showing a configuration of an example of the present invention.

FIG. 3 is a diagram showing the operation of the embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 PHS network switch 12 PHS base station 14 PHS mobile station 16 Note-PC

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04B ^7/ 24-7/26 102 H04Q ^7/ 00-7/38

Claims (5)

(57) [Claims] 1. A mobile station terminal capable of performing data communication in a mobile communication network, transmitting and receiving the data communication with the mobile station terminal, and transmitting the data communication to another terminal via the mobile communication network. A frame error rate threshold variation control method in a mobile communication network comprising: a base station that transmits and receives the mobile station terminal, the mobile station terminal and the base station, when performing the data communication, when the call quality is reduced, it is in use In order to start control to lower the frame error rate threshold value which is the error rate of the data frame with the value of the signal to be switched to another communication channel or switching to another base station, the mobile station terminal and the reference value in the base station. A frame error rate threshold variation control method for reducing the frame error rate threshold.
The base station obtains a communication type included in a call setup message from the mobile station terminal, and switches a communication channel in use when the communication is data communication, and controls switching to another base station. Reducing the frame error rate threshold value, which is signal information for starting the process, and notifying the mobile station terminal of the reduced value in order to reduce the frame error rate threshold value in a definition information response message. And a frame error rate threshold variation control method. 2. The mobile station terminal, when performing data communication with the base station, switches a communication channel in use, which is included in a definition information response message notified from the base station, and switches to another base station. Acquiring information on the frame error rate threshold, which is information for starting control of a signal to be switched, and further reducing the frame error rate threshold of the own terminal from the frame error rate threshold to reduce the frame error rate threshold. The method according to claim 1, wherein the frame error rate threshold is changed. Wherein the data communication is to connect the laptop computer to the mobile station terminal, according to claim 1 or 2, frame error rate threshold shift control method according and performs data communication. Wherein said mobile communication network, according to claim 1, 2 or 3 frame error rate threshold shift control method according to, characterized in that to connect to the Internet. Wherein said mobile communication network, according to claim characterized in that it is a personal handy phone system 1,2,3
Or the variation control method of the frame error rate threshold value according to 4 .