KR20010064592A - Method for allocating channel between base station controller and mobile switching center in mobile telecommunication system - Google Patents

Abstract

PURPOSE: A method for assigning channels between a BSC(Base Station Controller) and an MSC(Mobile Switching Center) in a mobile communication system is provided to notify the MSC of a digital signal processor's error, and to assign other channels. CONSTITUTION: If a call connection request incoming to an MSC(Mobile Switching Center) exists, the MSC requests a channel assignment to a BSC(Base Station Controller). The BSC checks a state of a corresponding digital signal processor. According to a checked result, the BSC transmits a channel assignment refusing or approving message to the MSC. The MSC requests the channel assignment to another digital signal processor according to the transmitted refusing message.

Description

Channel allocation between base station controller and switching center in mobile communication system {METHOD FOR ALLOCATING CHANNEL BETWEEN BASE STATION CONTROLLER AND MOBILE SWITCHING CENTER IN MOBILE TELECOMMUNICATION SYSTEM}

The present invention relates to channel assignment between an exchange station (MSC: MOBILE SWITCHING CENTER: hereinafter " exchange station ") and a base station controller (BSC: base station controller). The present invention relates to a method for allocating a channel in response to a DSP (DIGITAL SIGNAL PROCESSOR) error.

2 is a diagram illustrating allocation between a digital signal processor and a channel between a conventional base station controller and a switching center.

The system using the protocol V5.2 interface for call processing between the switching center 20 and the base station controller 10 will use 32 64 Kbps channels per E1 link. There are typically three E1 links between the switching center 20 and the base station controller 10. If the system transmits voice data, one channel is designed to pass one digital signal processor through a TIME switch.

However, in order to reduce the cost of the system, when the channel and the digital signal processor chip are used in one-to-one correspondence without the TIME switch between the digital signal processor pool 104 and the E1 cards 105 and 202, an error may occur in the digital signal processor. There is a time. Then there is a problem that the voice service can not be provided for the channel.

That is, when the switching center 20 allocates a channel to an error in the digital signal processor, there is a problem that service cannot be achieved.

In other words, as shown in FIG. 2, one digital signal processor provided in the base station controller 10 includes two pairs of 32 channels allocated to one RPC 203 provided in the switch 20. The call is handled one-on-one with the. However, if an error occurs in the digital signal processor in the base station controller 10, there is a problem that the corresponding channel cannot be used and the voice service allocated to the corresponding channel cannot be performed.

That is, even if an error occurs in the digital signal processor, the base station controller does not provide any information to the switching station, thereby preventing communication on the allocated channel. This is because the provision of the above information was unnecessary at all in the conventional TIME switch.

Accordingly, an object of the present invention is to provide a channel allocation method capable of coping with an error occurring in a digital signal processor included in a base station controller when allocating a channel between the base station controller and the switching center of the mobile communication system.

Another object of the present invention is to provide a channel allocation method that can cope with an error occurring in a digital signal processor when a channel is allocated between a base station controller and a switching station of a mobile communication system while satisfying the specification of V5.2.

Another object of the present invention is to provide a processing speed when allocating a channel between a base station controller and a switching center of a mobile communication system when allocating a channel in response to an error of a digital signal processor while satisfying the specification of V5.2. To provide a way to increase.

1 shows a schematic block configuration between a base station controller and a switching center according to an embodiment of the present invention.

2 is a diagram illustrating allocation between a digital signal processor and a channel between a conventional base station controller and a switching center.

3A and 3B are control flow diagrams for allocating channels by the first embodiment according to the present invention.

4a and b are flow charts for allocating channels according to a second embodiment of the present invention.

5a and b are control flowcharts for allocating channels according to a third embodiment according to the present invention.

In order to achieve the above objects, the present invention provides a method for allocating a channel between a base station controller and a switching station in a mobile communication system, the method comprising: requesting channel allocation to the base station controller when a call connection request is received by the switching station; When the base station controller requests a channel allocation from the switching center, checking a state of the digital signal processor, transmitting, by the base station controller, a channel allocation rejection or acknowledgment message to the switching center according to the check result; In response to said transmitted rejection message, said switching center requests channel assignment to another digital signal processor.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Specific details appear in the following description, which is provided to aid a more general understanding of the present invention, and it should be understood by those skilled in the art that the present invention may be practiced without these specific details. It will be self explanatory. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

1 shows a schematic block configuration between a base station controller and a switching center according to an embodiment of the present invention.

3A and 3B are control flow diagrams for allocating channels by the first embodiment according to the present invention.

4a and b are flow charts for allocating channels according to a second embodiment of the present invention.

5a and b are control flowcharts for allocating channels according to a third embodiment according to the present invention.

The operation of the first embodiment according to the present invention is described below with reference to FIGS. 1, 3A and 3B.

In step 300 of FIG. 3A, when a connection request is generated by call entry to the switching center 20, a channel allocation request is made to the base station controller 10. At this time, the request is sent to the base station controller with the E1 link, the channel and the subscriber information. The message becomes "MSGTYPE_ig_ALLOCATE_IND" in V5.2.

When the channel allocation request message is received, the base station controller 10 checks whether the state of the digital signal processor managing the corresponding channel that has requested channel allocation is in a good state. The inspection may be performed by searching the state data created according to the state information of the board periodically inspected by the base station controller 10. That is, the digital signal processor pool 104 checks whether the corresponding digital signal processor of the board is in a normal state. The operation may be performed by searching a table for managing an internal resource allocation state.

Typically, the base station controller 10 includes four digital signal processor boards, which are collectively referred to as a digital signal processor pool. Each board is assigned 32 channels, and each board has 16 digital signal processors. If the digital signal processor operates normally, the channel assignment acknowledgment message is transmitted. The acknowledgment message is "MSGTYPE_gi_ALLOCATE_COMP_REQ".

However, if the digital signal processor is not in a normal state, it transmits a reject message indicating that the channel cannot be allocated. The reject message is "MSGTYPE_gi_ALLOCATE_REJ_REQ". The following table shows the contents defined in V5.2 for transmitting the cause of the reject message transmission.

number bReject Cause Type Value Information One Unspecified 0x00 No Information Needed 2 Access network fault 0x01 No Information Needed 3 Access network blocked (interanlly) 0x02 No Information Needed 4 Connection already present at the PSTN user port to a different V5 time slot 0x03 wUserPortID 5 Connection already present at the V5 time slot (s) to a different port or ISDN user poer time slot 0x04 bV5timeSlotNumber 6 Connection already present at the ISDN user port time slot (s) to a different V5 time slot (s) 0x05 bISDNTimeSlotNumber 7 User port unavailable (blocked) 0x06 wUserportID 8 De-allocation cannot be completed due to incompatible data content 0x07 No Information Needed 9 De-allocation cannot be completed due to V5 time slot (s) data incompatibility 0x08 bV5TimeSlotNumber 10 De-allocation cannot be completed due to port data incompatibility 0x09 wUserPortID 11 De-allocation cannot be completed due to user port time slot (s) data incompatibility 0x0a bISDNTimeSlotNumber 12 User port not provisioned 0x0b wUserPortID 13 Invalid V5 time slot (s) identification (s) 0x0c bV5TimeSlotNumber 14 Invalid V5 2 048 kbit / s link identification 0x0d bV5TimeSlotNumber 15 Invalid user port time slot (s) identification (s) 0x0e bISDNTimeSlotNumber 16 V5 time slot (s) being used as physical c-channel (s) 0x0f bV5TimeSlotNumber 17 V5 link unavailable (bloked) 0x010 bE1LinkID

In an embodiment according to the present invention, the reject message may transmit a reject message using an "access network fault" corresponding to No. 2 of the table.

In the above table, number 1 indicates a reject message when an error out of the standard occurs, number 2 indicates a reject message when an error such as a system error or an overload occurs, and number 3 indicates a reject message by a corresponding user in use. 5 is a rejection message according to the use of the E1 link by another user, 6 is a rejection message when the ISDN is in use by another user, and 7 is a rejection message according to a bad subscriber. 7 to 11 show the rejection message according to the release error. 12 shows a reject message by an unsubscribed user, 13 shows a reject message according to an unused channel assignment, and 14 shows a reject message according to a link number error. No. 15 shows the reject message according to the ISDN user number error, no. 16 shows the reject message because the channel is the control channel, and no. 17 shows the reject message due to the E1 link itself error.

When the rejection message is received from the base station controller 10 in step 310, the switching center 20 transmits a message requesting channel allocation on a new channel.

Then, the base station controller 10 receives the channel allocation request message and checks the state of the corresponding channel. If the channel is in a normal state, the channel assignment acknowledgment message is transmitted to the switching center 20 in step 330.

3b shows the flow at the switching center 20 in the flow of FIG. 3a.

That is, the channel assignment request message is transmitted by call arrival (step 340), and when an acknowledgment message 350 for the corresponding channel is received, the call is connected to the corresponding channel. If an acknowledgment message is not received and a reject message is received, channel 360 requests channel assignment to another channel. At this time, the reject message received is a message according to an error of the digital signal processor.

Briefly explaining the embodiment according to Figure 3 as follows.

A channel allocation request is made by call initiation, and when a reject message by the digital signal processor is received, another channel allocation is requested to solve the problem of channel allocation due to an error of the digital signal processor.

A second embodiment according to the present invention is described below with reference to FIGS. 1 and 4A and 4B.

If a connection request is generated by call ingress to the switching center 20 in step 400 of FIG. 4A, a channel allocation request is made to the base station controller 10. The message becomes "MSGTYPE_ig_ALLOCATE_IND" in V5.2 as described above.

When the channel allocation request message is received, the base station controller 10 checks whether the state of the digital signal processor managing the corresponding channel that has requested channel allocation is in a good state.

If the digital signal processor operates normally, the channel assignment approval message is transmitted (step 430). The acknowledgment message is "MSGTYPE_gi_ALLOCATE_COMP_REQ".

However, if the digital signal processor is not in a normal state, it transmits a reject message indicating that the channel cannot be allocated (step 410). The reject message is "MSGTYPE_gi_ALLOCATE_REJ_REQ". In the embodiment according to the present invention, as described above, the reject message may be transmitted using the “access network fault” corresponding to No. 2 of the table.

When the reject message is received from the base station controller 10 in step 410, the switching center 20 stores that the corresponding digital signal processor cannot be used and transmits a message requesting channel allocation to a new channel.

Then, the base station controller 10 receives the channel allocation request message and checks the state of the corresponding channel. If the channel is in a normal state, the channel assignment approval message is transmitted to the switching center 20 in step 430.

FIG. 4B shows the flow at the switching center 20 in the flow of FIG. 4A.

In other words, the channel assignment request message is transmitted by call arrival (step 440), and when an acknowledgment message 450 for the corresponding channel is received, the call is connected to the corresponding channel. If the reject message is not received and the reject message is received, error information is stored in step 460 to stop using the channel for the digital signal processor. Thereafter, channel allocation to other channels is requested (470). At this time, the reject message received is a message according to an error of the digital signal processor.

Briefly describing the embodiment according to Figure 4 as follows.

By requesting a channel, a channel allocation request is made, and when a rejection message is received by the digital signal processor, the digital signal processor stores information forbidding the use of a channel that has already been allocated, and then requests the allocation of other channels. It solves the problem of channel allocation due to processor error. Since the embodiment according to FIG. 4 stores digital signal processor information in which an error occurs unlike the embodiment according to FIG. 3, the call allocation is not required for the call request to the same digital signal processor afterwards. Time will be reduced.

A third embodiment according to the present invention is described below with reference to FIGS. 1, 5A and 5B.

When a connection request is generated by call entry to the switching center 20 in step 500 of FIG. 5A, a channel allocation request is made to the base station controller 10 by a previously stored candidate list. The candidate list allocates a channel according to call arrival. It is a list for the purpose of doing so, and it is usually arranged to allocate channels. The list includes the error information of the digital signal processor of the base station controller 10 so as not to allocate a channel to the corresponding channel when an error occurs. The channel allocation request message becomes "MSGTYPE_ig_ALLOCATE_IND" in V5.2 as described above.

When the channel allocation request message is received, the base station controller 10 checks whether the state of the digital signal processor managing the corresponding channel that has requested channel allocation is in a good state.

If the digital signal processor operates normally, the channel assignment approval message is transmitted (step 520). The acknowledgment message is "MSGTYPE_gi_ALLOCATE_COMP_REQ".

However, if the digital signal processor is not in a normal state, it transmits a reject message indicating that the corresponding channel cannot be allocated (step 510). The reject message is "MSGTYPE_gi_ALLOCATE_REJ_REQ". In the embodiment according to the present invention, as described above, the reject message may be transmitted using the “access network fault” corresponding to No. 2 of the table.

Thereafter, the base station controller 10 drives a process for recovery confirmation.

When the reject message is received, the switching center 20 updates the candidate list so that channel assignment is no longer required to the channel assigned to the digital signal processor according to the received reject message. The switching center 20 transmits a message requesting channel allocation to a new channel by the updated candidate list, and the base station controller 10 returns to step 500 to repeat the above operation.

The operation of the process for recovery confirmation is described below with reference to FIG. 5B.

In response to an error, the base station controller 10 checks whether the corresponding digital signal processor is restored. If so, the process proceeds to step 560 where a recovery message is sent to the switching center. The recovery message includes information of the recovered digital signal processor. Upon receiving the recovery message, the switching center 20 updates the candidate list according to the reception of the recovery message and then refers to the channel assignment request message transmission according to the call arrival.

In the above example, by sending a reject message by call assignment, an error of the digital signal processor is notified to the switching center 20. However, when an error of the digital signal processor is generated by the inspection of the base station controller 10, the digital signal is immediately transmitted. It may also indicate a processor error.

Briefly describing the embodiment according to Figure 5 as follows.

If the base station controller 10 transmits the error occurrence or recovery information according to the error of the digital signal processor to the switching center 20, the switching center 20 updates the candidate list according to the transmitted information, and there is a call connection request. The base station controller 10 requests channel allocation by the candidate list. Thus, unlike the embodiments of FIGS. 3 and 4, the digital signal processor may deal with errors in real time. On the other hand, although the first and second embodiments to be described above may be made within the existing protocol of V5.2, the embodiment according to FIG. 5 may require a message setting for transmitting and receiving a separate message.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims below, but also by the equivalents of the claims of the present invention.

As described above, the present invention provides a base station controller when allocating a channel between the base station controller and the switching station of the mobile communication system by allocating another channel by informing the switching station of an error of the digital signal processor according to the channel allocation request. It is possible to cope with the error occurrence of the digital signal processor, and when the channel is allocated between the base station controller and the switching station of the mobile communication system, it is possible to cope with the error occurrence of the digital signal processor while satisfying the specification of V5.2. When allocating a channel between the base station controller and the switching center of the system, the processing speed can be increased when the channel is allocated in response to the error of the digital signal processor while satisfying the specification of V5.2.

Claims (6)

A channel allocation method between a base station controller and a switching station in a mobile communication system, Requesting channel assignment to the base station controller when the switching center receives a call connection request from the switching center; Checking, by the base station controller, a state of the digital signal processor when a channel allocation request is made from the switching center; Transmitting, by the base station controller, a channel allocation rejection or acknowledgment message to the switching center according to the check result; And the exchange requesting channel allocation to another digital signal processor in accordance with the transmitted reject message. The method of claim 1, wherein the reject message, Method characterized by the "ACCESS NETWORK FAULT". A channel allocation method between a base station controller and a switching station in a mobile communication system, Requesting channel allocation to the base station controller according to a candidate list if the switching center has a call connection request coming into the switching station; Checking, by the base station controller, a state of the digital signal processor when a channel allocation request is made from the switching center; Transmitting, by the base station controller, a channel allocation rejection or acknowledgment message to the switching center according to the check result; The exchange switching the channel of the digital signal processor from the candidate list according to the transmitted reject message; And the exchange requesting channel allocation to another digital signal processor. The method of claim 3, wherein the reject message, Method characterized by the "ACCESS NETWORK FAULT". A channel allocation method between a base station controller and a switching station in a mobile communication system, Transmitting, by the base station controller, error occurrence or recovery information according to an error occurrence of a digital signal processor to the switching center; Wherein the switching station updates the candidate list according to the transmitted information and requests channel allocation from the candidate list to the base station controller according to the call list request. The method of claim 5, wherein the transmission of the error occurrence information, And the base station controller examines the channel allocation requested digital signal processor in response to a channel allocation request of the switching center to detect an error.