KR20020036056A - Method for allocating resources of BTS in mobile communication system - Google Patents

Abstract

PURPOSE: A method for allocating a base station resource in a mobile communication system is provided to enable a user to receive a high-quality calling service by assigning a frequency having the least load using actual frequency resource assignment information and restricting the number of MDRs(Middle Data Rates) as a subcell unit. CONSTITUTION: In a method for assigning a base station resource in a mobile communication system, it is judged whether a called call is an FDB(Fundamental Data Block) or not(S1). If the called call is not an FDB, a B-Link resource/frame offset resource is assigned(S2) and it is confirmed whether the number of traffic channels assigned to the corresponding subcell is larger than a normal_call_block(S3). If the number of traffic channels assigned to the corresponding subcell is lower than the normal_call_block, a resource is assigned(S7). If the number of traffic channels assigned to the corresponding subcell is larger than the normal_call_block, a resource is assigned by distributing a load. If the called call is an FDB, a resource is assigned by distributing a load.

Description

Method for allocating base station resources in mobile communication system {Method for allocating resources of BTS in mobile communication system}

The present invention relates to resource allocation of a base station in a CDMA mobile communication system. In particular, by limiting the number of middle data rates (MDRs) to subcell units in a data service exceeding 14 Kbps, a user can obtain high quality. The present invention relates to a method for allocating base station resources in a mobile communication system to receive a call service.

1 is a diagram showing the configuration of a general CDMA mobile communication system.

As shown, a mobile station 1, which is a terminal device that allows a mobile subscriber to communicate through a mobile communication network; A base transceiver station (2) for communicating with the terminal (1) using a protocol defined in IS-95 in a wireless section; A base station controller 3 which controls a radio link and a wire link and performs a hand off function for maintaining the continuity of a call even when a subscriber is moving; A mobile switching center 4 for constructing a subscriber's call path and performing connection with another communication network; Subscriber information is stored, and consists of a Home Location Register (5) for exchanging signals with the switching center (4), through the base station (2), the control station (3) and the switching station (4) It is an apparatus for realizing a call of the terminal 1.

In the CDMA mobile communication system configured as described above, a base station control processor (BCP) in a multi-FA base station having two or more frequency channel resources receives the resources (blink, frequency channel, frame offset, Walsh code, power, traffic channel, etc.).

In the conventional method for the base station resource allocation, the mobile station determines the frequency channel information transmitted from the base station and the hash function result value of its own terminal number as the service frequency channel. To be distributed randomly.

In addition, the traffic channel is divided into a fundamental data block (FDB) and an additional data block (SDB) for an MDR service for high-speed data communication. Depending on the data rate (up to 64kbps), only the channels that require SDB (up to 4 channels) are set.

The appointment between the base station and the mobile station is defined in the specification, and works well in a situation where the traffic allocation of the base station is distributed evenly over all frequency channels.

However, when the traffic channel is concentrated on a specific frequency or when the MDR service is set up in a busy time, or when the MDR service is concentrated on a specific FA, the frequency channel is heavily loaded due to the random frequency channel distribution method. There is a problem in that a voice channel or an MDR can be reassigned, and this also affects mutual interference between mobile stations, thereby degrading the quality of service and limiting the voice call service due to data service.

Accordingly, the present invention has been proposed to solve various problems according to the prior art as described above,

An object of the present invention is to allocate a frequency with the least load by using substantial frequency resource allocation information and to limit the number of MDRs to subcell units, thereby enabling a user to receive high quality call service. The present invention provides a method for allocating base station resources.

The present invention for achieving the above object,

When performing a load balancing algorithm, the Round Trip Delay (RTD), which can predict the distance of the mobile station, is compared with the RTD threshold, and when the mobile station's RTD is larger than the RTD threshold, it is assumed to be in a neighboring base station. Search for the least loaded FA in the order of) and Unique FA, and search for the least loaded FA in the order of Unique FA and Common FA when the RTD of the mobile station is less than the RTD threshold. Allocate the resources of the base station to.

In addition, the present invention for achieving the above object,

When the received call is an FDB rather than a voice call, an idle TCE (traffic channel element) versus normal-call-block (ID_) is considered in consideration of an SDB allocation to be generated later when allocating resources of the base station. The FA is allocated only if the ratio of S is greater than the ratio of restricting the traffic channel of the MDR service for guaranteeing the voice call service.

1 is a view showing the configuration of a general CDMA mobile communication system,

2 is a flowchart illustrating a method for allocating base station resources in a mobile communication system according to the present invention.

<Explanation of symbols for the main parts of the drawings>

1: terminal (MS)

2: base station (BTS)

3: control station (BSC)

4: switching center (MSC)

5: Home Location Register (HLR)

Hereinafter, a method for allocating a base station resource in a mobile communication system according to the present invention according to the technical spirit as described above will be described in detail with reference to the accompanying drawings.

To increase call capacity and provide good call quality, CDMA systems use forward and reverse power control. Through transmission power control for all mobile stations, system capacity can be maximized if the mobile station's originating signal is received at the base station with a minimum required level of signal-to-interference ratio.

However, if the signal of the mobile station is received too weak, the operating performance of the mobile station is degraded. If the signal of the mobile station is strongly received, the operating performance of the mobile station is improved, but the interference to other mobile stations using the same channel is increased to reduce the maximum capacity. Unless the other subscriber's call quality falls below that level.

Resources allocated to originating / receiving calls by the base station receiving the call of the mobile station include FA, blink, frame offset, Walsh code, traffic gain, traffic channel, etc. Among them, the traffic channel is constant for each subcell. In order to guarantee the quality of sound quality, the limit is set by the normal call block threshold, and one call is allocated to each base station.

On the other hand, MDR for high-speed data service is composed of an FDB that sets up a call like a basic call and an SDB for processing high-speed data up to 64kbps. That is, SDB is required for FTP (File Transfer Protocol) and WAP (Wireless Application Protocol) after setting up a call to FDB, and when the base station allocates resources for it, MDR service is performed. Up to four SDBs can be configured at the base station for high-speed data communication up to 64 kbps.

In the present invention, in order to improve a certain level of call quality guarantee and voice call service guarantee, if the MDR service is already above a threshold, the traffic channel resource is searched for another FA to find a resource having the least load and satisfying the threshold. Assign to MDR service.

Hereinafter, a preferred embodiment of the present invention will be described.

2 is a flowchart illustrating a method for allocating base station resources in a mobile communication system according to the present invention.

First, in step S1, it is checked whether it is an FDB or a voice call. That is, when the origination / page response is received from the mobile station, the base station determines the type of the call for which resource allocation is requested using the service option. Where FDB has service options 22 to 29.

As a result of the determination of step S1, if it is not FDB, that is, a voice call, in step S2, a B-Link resource and a frame offset for transmitting voice data are allocated to the control station BSC.

Subsequently, in step S3, it is determined whether the number of traffic channels allocated to the corresponding subcell is larger than the normal_call_block. Here, the normal-call-block corresponds to the call block threshold of the general call.

As a result of the checking in step S3, if the number of traffic channels allocated to the corresponding subcell is smaller than the normal-call-block, the mobile station moves to step S7 to allocate base station resources such as Walsh code, traffic gain, and traffic channel after FA allocation. Proceed with call setup. In contrast, when the number of track channels allocated to the corresponding subcell is larger than the normal-call-block, resources are allocated by the load distribution algorithm.

That is, in consideration of the handoff in step S4, the RTD value of the call received by the mobile station is compared with the RTD threshold in the PLD (Program Loading Data). Here, the RTD threshold is a parameter that can predict the distance between the base station and the mobile station.

As a result of the comparison of step S4, if the RTD value of the mobile station is larger than the RTD threshold, the mobile station is considered to be in an adjacent area of the base station. In step S5, the FA having the least load in the common FA, that is, the FA with the lowest number of calls, is searched for. Return a value. Here, the common FA is a frequency commonly used with neighboring base stations, and soft handoff occurs when a handoff occurs to another base station.

Subsequently, in step S6, it is checked whether the FA is valid, that is, 0xff. If it is not 0xff, the process moves to step S7 after allocating the FA, and allocates base station resources such as Walsh code, traffic gain, and traffic channel to proceed with call setup. Where 0xff points to hexadecimal ff.

If the FA is 0xff in step S6, the smallest FA in the unique FA, that is, the FA with the smallest number of calls, is searched for and returned in step S8.

The unique FA is a frequency used only for a specific base station, and hard handoff occurs when a handoff occurs.

Subsequently, in step S6, if the FA is 0xff, and if it is not 0xff, the process moves to the aforementioned step S7, and after FA allocation, base station resources such as Walsh code, traffic gain, and traffic channel are allocated to proceed with call setup. In contrast, if the FA is 0xff, it is assumed that there is no traffic channel to allocate and the call setup ends.

On the other hand, if the RTD value of the call received by the mobile station in step S4 is compared with the RTD threshold in the PLD, if the RTD value of the mobile station is smaller than the RTD threshold, the unique FA is searched for in step S10, that is, the number of calls is the smallest. Returns the lowest FA.

In step S11, if it is determined that the returned FA is 0xff, and if it is 0xff, the process proceeds to step S7 described above, and after FA is allocated, base station resources such as Walsh code, traffic gain, and traffic channel are allocated to proceed with call setup.

On the contrary, if the returned FA is 0xff, the FA having the smallest load among the common FAs is returned in step S12.

Subsequently, in step S13, it is determined whether the FA is 0xff, and if it is not 0xff, the process moves to step S7 described above, and after FA allocation, base station resources such as Walsh code, traffic gain, and traffic channel are allocated to proceed with call setup. If 0xff, it is determined that there is no traffic channel to allocate and the call setup ends.

The above-described step S2 to step S13 correspond to the base station resource allocation method in the case of the voice call as a result of the confirmation in step S1, and the resource allocation method in the case of FDB will be described below.

If the service option corresponds to the FDB in step S1, in step S14, a B-Link resource and a frame offset for transmitting voice data with the control station are allocated.

Subsequently, in step S15, the RTD value of the call received by the mobile station is compared with the RTD threshold value in the PLD. If the RTD value of the mobile station is larger than the RTD threshold value, the lowest FA among the common FAs is searched and returned in step S16. However, since the SDB allocation to be generated must be considered, the FA is allocated only when the ratio of the traffic channel element (TCE) to normal-call-block (TCE) in idle state is larger than mdr_tce_reserved_percent.

In this case, mdr_tce_reserved_percent indicates a percentage (%) for restricting a traffic channel allocated to the MDR service to guarantee the voice call service, and usually has a value of 20%.

In step S17, if it is determined that the returned FA is 0xff, and if it is 0xff, the process moves to step S18, and after FA allocation, base station resources such as Walsh code, traffic gain, and traffic channel are allocated to call setup.

On the contrary, when the returned FA is 0xff, in step S19, the lowest FA allocated from the unique FA is searched for and returned. However, the FA is allocated only when the ratio of the traffic channel element (TCE) to normal-call-block (TCE) in the idle state is larger than mdr_tce_reserved_percent in consideration of a later SDB allocation.

Then, in step S20, as described above, it is determined whether the FA is 0xff, and if it is 0xff, it is assumed that there is no traffic channel to be allocated, and the call setup is terminated. Call setup is performed by allocating base station resources such as traffic gain and traffic channel.

On the other hand, when the RTD value of the call received by the mobile station in step S15 is compared with the RTD threshold value in the PLD, if the RTD value of the mobile station is smaller than the RTD threshold value, the lowest FA allocated in the unique FA is searched and returned in step S21. (Return) Also, the FA is allocated only when a ratio of a traffic channel element (TCE) to a normal-call-block (TCE) in idle state is larger than mdr_tce_reserved_percent in consideration of a later SDB allocation.

Subsequently, in step S22, it is checked whether the FA is 0xff, and if it is not 0xff, the process moves to the above-described step S18 and repeats the following steps. Otherwise, if the FA is not 0xff, the lowest allocation is made in the common FA in step S23. Search for the returned FA and return it. However, FA is allocated only when the ratio of TCE (Traffic Channel Element) to normal-call-block in idle state is larger than mdr_tce_reserved_percent.

Then, in step S24, if the FA is 0xff, and if it is 0xff, go to step S18 described above and repeat the steps below. If the FA is 0xff, the call setup is regarded as having no traffic channel to be allocated and the call setup ends. do.

As described above, in the mobile communication system according to the present invention, an allocation method of base station resources is provided.

By allocating the frequency with the least load by using the actual frequency resource allocation information and limiting the number of MDRs in units of subcells, there is an advantage of distributing the load between the base station and the subcells and maintaining the call quality of the data call. There is an advantage to that.

In addition, when allocating the frequency of the MDR, there is an effect that hard handoff does not occur in consideration of the handoff of the RTD value of the mobile station.

Claims (4)

In the method of allocating base station resources in a mobile communication system, Determining whether the received call is an FDB; If the received call is not an FDB, allocates a B-Link resource / frame offset resource and checks whether the number of traffic channels allocated to the corresponding subcell is larger than a normal_call_block. Steps; A third step of allocating resources when the number of traffic channels allocated to the subcells is smaller than a normal-call-block as a result of the checking; A fourth step of allocating resources by distributing the load when the number of traffic channels allocated to the subcell is larger than the normal-call-block as a result of the checking of the second step; And a fifth step of allocating resources by distributing a load if the received call is an FDB as a result of the determination of the first step. 2. The method of claim 1, wherein if the number of traffic channels allocated to the subcells is greater than the normal-call-block, allocating the resources by distributing the load comprises comparing the RTD value of the mobile station with the RTD threshold in the PLD. A first step; A second step of searching for an FA having the least load among common FAs by considering the neighboring base station if the RTD value of the mobile station is larger than the RTD threshold as a result of the comparison in the first step; A third step of checking whether the searched FA is valid and allocating resources if it is valid, and searching for the FA having the least load among unique FAs if it is not valid; A fourth step of checking whether the FA found as having the least load among the unique FAs is valid and allocating resources if they are valid, and ending the call setup if there is no traffic channel to allocate if not valid; A fifth step of searching for an FA having the least load among the unique FAs, considering that the RTD value of the mobile station is less than the RTD threshold, the mobile station is not in an adjacent region of the base station; A sixth step of checking whether the searched FA is valid and allocating resources if valid, and searching for the FA having the least load among common FAs if it is not valid; And a seventh step of allocating resources if it is found that the FA found as having the least load among the common FAs is valid and assigning resources if it is not valid. An allocation method of base station resources in a mobile communication system. 2. The method of claim 1, wherein if the received call is an FDB, distributing the load to allocate resources comprises: a first step of comparing the RTD value of the mobile station with the RTD threshold in the PLD; A second step of searching for an FA having the least load among common FAs by considering the neighboring base station if the RTD value of the mobile station is larger than the RTD threshold as a result of the comparison in the first step; A third step of checking whether the searched FA is valid and allocating the resource if it is valid, and searching for the FA having the least load among unique FAs if it is not valid; A fourth step of checking whether the FA found as having the least load among the unique FAs is valid and allocating the resources if they are valid, and ending the call setup if there is no traffic channel to allocate if they are not valid; A fifth step of searching for an FA having the least load among the unique FAs, considering that the RTD value of the mobile station is less than the RTD threshold, the mobile station is not in an adjacent region of the base station; A sixth step of checking whether the searched FA is valid and allocating the resource if it is valid, and searching for the FA having the least load among common FAs if it is not valid; And a seventh step of allocating the resources if valid FA is found to have the least load among the common FAs, and if it is not valid, assumes that there is no traffic channel to allocate. A base station resource allocation method in a mobile communication system, characterized in that. 4. The method of claim 3, wherein the searching and assigning the FA having the least load in the common FA and the searching and allocating the FA with the least load in the unique FA further ensure the voice call service when allocating the SDB. In order to allocate a base station resource in a mobile communication system, the FA is allocated only when a ratio of a traffic channel element (TCE) in a idle state (TCE) to a normal_call_block is larger than a predetermined value. .