JP3321360B2 - Mobile communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a mobile communication system including a mobile station (PS), a base station (BS), and a mobile switching center (MSC), and more particularly, to a mobile communication system (BS-MSC) for performing site diversity. The transmission efficiency is improved.

[0002]

2. Description of the Related Art A mobile communication system including a mobile station (PS), a base station (BS), and a mobile switching center (MSC), as shown in FIG.
And a base station 2 and an MSC 3 that collects information from the base station 2 via a wired line. The base station 2 receives a signal from the mobile station 1, and transmits the received signal to the MSC 3.
3 and a wired transmission unit 22 for transferring the data to the MSC3.
Includes a wired receiving unit 31 that receives signals transferred from the plurality of base stations 2, a selecting and combining unit 32 that selects a signal with high reliability from the signals received by the wired receiving unit 31,
And a data processing unit 33 for performing data processing using the selected signal.

[0003] Information transmission between the BS and the MSC is performed by ATM (asynchronous transmission) as described in the 1996 IEICE General Conference B-333 "Low-speed voice information ATM transmission system for next-generation mobile communication networks". Mode) This is performed using the transmission path 4.

In this mobile communication system, a radio frame transmitted from a mobile station 1 is received by each base station 2,
The data is collected in the wired receiving unit 31 of the MSC 3 through the M transmission path 4. The selecting / combining unit 32 of the MSC 3 selects a frame with the highest reliability from the frames received from the plurality of base stations 2 and passes it to the data processing unit 33, and the data processing unit 33 uses the passed data. Perform data processing.

As described above, in this system, high quality communication can be performed by performing site (base station) diversity for selecting a base station in frame units.

[0006]

However, in this conventional mobile communication system, an AT is used for information transmission between the BS and the MSC.
Since two or more M links are used, there is a problem that the use efficiency of the transmission path is poor.

An object of the present invention is to solve such a conventional problem, and an object of the present invention is to provide a mobile communication system capable of improving the transmission efficiency of a transmission line in a system.

[0008]

Therefore, in the mobile communication system of the present invention, even a frame received from a mobile station, data of a received frame with low reliability is rejected by the base station. I have.

Therefore, the amount of data transmitted from the base station to the MSC is reduced, and the transmission efficiency of the ATM link between the BS and the MSC can be increased.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention comprises a mobile station (PS), a base station (BS), and a mobile switching center (MSC).
In a mobile communication system in which a received frame is transferred from the S to the MSC and site diversity is performed on a frame basis, the BS determines whether the frame received from the PS should be discarded or transferred to the MSC based on the reliability information. A frame transfer determining means and a threshold storing means for storing a threshold value used for the determination by the frame transfer determining means are provided. Transmission efficiency.

[0011] The invention according to claim 2 is characterized in that the MSC has a BS
Threshold change means for instructing the change of the threshold value stored in the threshold value storage means, and wired transmission means for transmitting the threshold change instruction to the BS. , Can be changed from the MSC side.

According to a third aspect of the present invention, a BS is provided with a call number corresponding threshold value changing means for changing a threshold value stored in the threshold value storing means in accordance with the number of currently communicating calls.
The amount of data transmitted between the BS and the MSC can be adjusted according to the number of calls currently being communicated in S, and the transmission link between the BS and the MSC can be used effectively.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

(First Embodiment) A mobile communication system according to a first embodiment has a base station (BS) as shown in FIG.
2, a wireless receiving unit 21 for receiving a signal from the mobile station (PS) 1, a frame transfer determining unit 23 for determining whether to transfer the received frame to the MSC 3, and a threshold used for this determination. And the frame determined to be transferred to the MSC 3 through the ATM transmission line 4.
And a wire transmission unit 22 for transferring the data to the MSC.
Reference numeral 3 denotes a wired receiving unit 31 that receives frames transferred from the plurality of base stations 2, and a selecting / combining unit 32 that selects a highly reliable frame from the frames received by the wired receiving unit 31.
And a data processing unit 33 for performing data processing using the signal selected by the selection / combination unit 32.

In this system, as shown in FIG. 2, step 1: first, a radio frame transmitted from the mobile station 1 is received by the radio receiving section 21 of the base station 2, and the data of the frame and the reliability of the data are determined. The information indicating the degree (for example, the reception level) is passed to the frame transfer determination means 23.

Step 2: The frame transfer determining means 23
The passed reliability information is compared with a threshold value of reliability stored in advance in the threshold value storage means 24. Step 3: If the reliability information is lower than the threshold value, it is determined to discard the frame. If the degree information is higher than the threshold, the transfer of the frame to the MSC 3 is determined.

The wired transmission unit 22 of the base station 2 transfers the data of the frame determined to be transferred to the MSC 3 and the reliability information thereof to the MSC 3 via the ATM transmission line 4.

The wire receiving unit 31 of the MSC 3 receives the data transferred from the base station 2 and passes the data to the selecting / combining unit 32. If there are a plurality of received frames, the selecting / combining unit 32 selects the received frame. The frame with the highest reliability is selected and passed to the data processing unit 33.

As described above, in the mobile communication system of this embodiment, by providing the base station with the frame transfer judging means, it is possible to suppress unnecessary frames from flowing on the ATM transmission line, and to multiplex the ATM transmission line. Effect can be increased.

(Second Embodiment) In the mobile communication system according to the second embodiment, a threshold value for judging whether or not to transfer a frame can be changed from the MSC.

In this system, as shown in FIG. 3, the base station 2 includes a wired receiving unit 25 for receiving a threshold change instruction message transmitted from the MSC 3.
3 includes a threshold changing unit 34 for requesting a threshold change, and a wired transmitting unit 35 for transmitting a threshold change instruction message to the base station 2. Other configurations are the same as those of the first embodiment (FIG. 1).

In this system, the base station 2 discards received frames in accordance with the procedure shown in FIG. 2 and transfers frames whose reliability information is higher than a threshold value to the MSC 3.

In the MSC 3, the wired receiving unit 31 receives the frame transferred from the base station 2, and the data processing unit 33 performs the data processing. When receiving frames from a plurality of base stations 2, the selection / synthesis unit 32 selects the frame with the highest reliability among them and passes it to the data processing unit 33.

The threshold changing means 34 of the MSC 3 outputs a request for changing the threshold according to the reception status of the frame. In this case, as shown in FIG. 4, Step 10: When a threshold change request is output, Step 11: A threshold change instruction message is transmitted from the wire transmission unit 35 of the MSC 3, and Step 12: A wire reception unit of the base station 2. Received at 25.

Step 13: The base station 2 changes the threshold stored in the threshold storage 24 based on the threshold change instruction.

The frame transfer judging means 23 judges whether or not the transfer of the received frame is to be performed using the newly set threshold value.

As described above, in the mobile communication system according to the second embodiment, the threshold value for discarding unnecessary frames can be changed from the MSC if necessary.
It is possible to adjust the multiplexing of the ATM transmission line according to the reception status at C, etc., and to effectively use the transmission link between the base station and the MSC.

(Third Embodiment) In the mobile communication system according to the third embodiment, the threshold for judging whether frame transfer is appropriate is changed by the base station according to the number of calls during communication.

In this system, as shown in FIG. 5, the base station 2 is provided with a call number corresponding threshold changing means 26 for changing a threshold according to the number of calls during communication. Other configurations are the same as those of the first embodiment (FIG. 1).

In this system, the threshold changing means 26 for the number of calls of the base station 2 stores the threshold storing means 24 according to the number of calls during communication.
Is automatically changed, and the frame transfer determining means 23 uses this threshold to determine whether or not the received frame needs to be transferred to the MSC 3.
Other operations are the same as those of the first embodiment.

In the mobile communication system according to the third embodiment,
Since the threshold for discarding unnecessary frames is changed according to the number of calls during communication at each base station, automatic adjustment of multiplexing of the ATM transmission line based on the actual communication state becomes possible,
Effective use of the transmission link between the base station and the MSC can be achieved.

[0032]

As is apparent from the above description, the mobile communication system of the present invention can increase the transmission efficiency between the base station and the MSC by providing the base station with the frame transfer judging means.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a mobile communication system according to a first embodiment of the present invention;

FIG. 2 is a flowchart showing an operation procedure in the mobile communication system according to the first embodiment;

FIG. 3 is a configuration diagram of a mobile communication system according to a second embodiment of the present invention;

FIG. 4 is a flowchart showing an operation procedure in the mobile communication system according to the second embodiment;

FIG. 5 is a configuration diagram of a mobile communication system according to a third embodiment of the present invention;

FIG. 6 is a configuration diagram of a conventional mobile communication system.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 mobile station (PS) 2 base station (BS) 3 mobile switching center (MSC) 4 ATM transmission line 21 wireless receiving unit (BS) 22 wired transmitting unit (BS) 23 frame transfer determination unit (BS) 24 threshold storage unit ( BS) 25 Wired receiving unit (BS) 26 Call number threshold changing unit (BS) 31 Wired receiving unit (MSC) 32 Selective combining unit (MSC) 33 Data processing unit (MSC) 34 Threshold changing unit (MSC) 35 Wired transmission Department (MSC)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI H04Q 7/30

Claims (3)

(57) [Claims] 1. A mobile station, a base station, and a mobile switching center. A received frame is transferred from the base station to the mobile switching center on a transmission path between the base station and the mobile switching center, and site diversity is performed on a frame basis. A mobile communication system, wherein the base station determines, based on reliability information, whether a frame received from a mobile station should be discarded or transferred to a mobile switching center; and And a threshold value storage unit for storing a threshold value for use in the determination of the mobile communication system. 2. The mobile switching center according to claim 1, further comprising: a threshold changing unit that issues a command to change a threshold stored in a threshold storing unit of the base station; and a wire transmitting unit that sends the threshold changing command to the base station. The mobile communication system according to claim 1, comprising: 3. The system according to claim 1, wherein said base station includes a call number corresponding threshold value changing means for changing a threshold value stored in said threshold value storage means according to the number of calls currently in communication. A mobile communication system according to claim 1.