KR101220533B1 - Method for Allocating Resource of Orthogonal Variable Spreading Factor Code in Asynchronous Communication Network - Google Patents

Abstract

The present invention relates to a method for reallocating an OVSF code when establishing a High Speed Downlink Packet Access (HSDPA) call in an asynchronous mobile communication system.

According to the present invention, when a high speed forward packet access (HSDPA) call is received, an orthogonal variable spreading coefficient code using less than 16 of a plurality of orthogonal variable spreading coefficient (OVSF) codes allocated to all access (Non HSDPA) calls except high speed forward packet access. It is possible to efficiently allocate OVSF codes for HSDPA services, including the step of reassigning the code to the same size code, thereby improving the data transmission speed that can be supported by the cell, and efficiently HSDPA calls and Non HSDPA calls. Can manage

HSDPA

Description

Method for Allocating Resource of Orthogonal Variable Spreading Factor Code in Asynchronous Communication Network in Asynchronous Mobile Communication System

1 is a diagram showing a tree structure of a general OVSF code;

2 is a view for explaining a general OVSF code allocation method,

3 is a diagram illustrating an example of OVSF code reassignment for a conventional HSDPA communication service;

4 is a diagram showing the configuration of a mobile communication network according to the present invention;

5 is a view showing a state before code reallocation according to the present invention;

6 is a view showing a state after code reallocation according to the present invention;

7 is a flowchart illustrating a method for allocating OVSF code resources according to the present invention.

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

100: mobile communication terminal 210: Node B

230: RNC 250: MSC

270 core network

The present invention relates to a method for allocating OVSF code resources in an asynchronous mobile communication system, and more particularly, to a method for reallocating an OVSF code when establishing a High Speed Downlink Packet Access (HSDPA) call in an asynchronous mobile communication system.

The asynchronous mobile communication system employs an Orthogonal Variable Spreading Factor (hereinafter referred to as "OVSF") technique in which the length of an orthogonal code varies depending on the data transmission rate on the forward and reverse channels.

In the asynchronous mobile communication system, since the data transmission rate is determined according to the OVSF code allocated to the call attempt, the OVSF code resource must be efficiently managed to allocate sufficient resources to many subscribers.

In more detail with reference to Fig. 1 showing the tree structure of the OVSF code, the OVSF code allocation method uses the OVSF 4 code to allocate four channels (shown in blue dashed lines in Fig. 1) that require an OVSF 4 code, or Allocate one OVSF 4 code channel (indicated by the red dotted line in FIG. 1) and six channels that require an OVSF 8 code (indicated by the red dotted line in FIG. 1).

At this time, the lower code (DOWN BLOCK of FIG. 2) and the higher code (UP BLOCK of FIG. 2) of the allocated OVSF code (USE of FIG. 2) and the allocated OVSF code (USE of FIG. 2) are allocated as illustrated in FIG. 2 to explain the OVSF code allocation method. Can't.

Meanwhile, High Speed Downlink Packet Access (hereinafter referred to as "HSDPA") uses OVSF 16 codes. One mobile communication terminal can simultaneously use up to 15 OVSF 16 codes and 15 OVSF 16 codes. The code supports downlink speeds of 14.4 Mbps. As shown in FIG. 3, which shows an example of reassigning OVSF codes for the HSDPA service, when two channels of the OVSF 32 code for Non HSDPA are allocated, up to 14 OVSF codes for the HSDPA can be used. Here, one remaining code is assigned to the common channel and not to the HSDPA channel.

If, as shown in FIG. 3, codes 32 to 512 or less of OVSF 16 codes are randomly allocated and 14 OVSF 16 codes are not available, the code utilization cannot be maximized. The problem arises that the optimal state cannot be maintained.

Therefore, there is a need for a method of reallocating an optimal OVSF code for HSDPA.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides an OVSF code resource allocation method in an asynchronous mobile communication system for providing an optimal OVSF code allocation method when allocating an HSDPA call in an asynchronous mobile communication system. have.

The present invention for achieving the above object is an orthogonal variable spreading coefficient code resource allocation method in an asynchronous mobile communication system,

When a fast forward packet access (HSDPA) call is introduced, an orthogonal variable spreading factor code using less than 16 of a plurality of orthogonal variable spreading factor (OVSF) codes allocated to all access (Non HSDPA) calls except the fast forward packet access is the same size. Reassignment to the code of; includes.

Another invention is an orthogonal variable spreading coefficient code resource allocation method in an asynchronous mobile communication system,

a) if a high speed forward packet access (HSDPA) call is received, checking whether an orthogonal variable spreading factor (OVSF) 16 code for the high speed forward packet access (HSDPA) is allocated equal to a preset number; And b) if the orthogonal variable spreading coefficient 16 code is allocated equal to a preset number as a result of the checking in step a), allocating the remaining orthogonal confidence coefficient codes to all access calls except for the fast forward packet access; do.

Another invention is an orthogonal variable spreading coefficient code resource allocation method in an asynchronous mobile communication system,

a) if an HSDPA call is incoming, assigning an orthogonal variable spreading factor code to all access calls except high speed forward packet connections; And b) assigning the remaining orthogonal variable spreading coefficient code allocated in step a) to the fast forward packet access call.

Another invention is an orthogonal variable spreading coefficient code resource allocation method in an asynchronous mobile communication system,

a) if an HSDPA call is incoming, assigning an orthogonal variable spreading coefficient code resource to a high speed forward packet access call first; And b) allocating the remaining orthogonal variable spreading coefficient code allocated in step a) to all access calls except for the fast forward packet access call.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is a diagram illustrating a configuration of a mobile communication network according to the present invention, which will be described with reference to FIG. 5, which shows before code reallocation, and FIG. 6, which shows after code reallocation.

As shown in the drawing, the asynchronous mobile communication system is connected to a Node B 210 as a base station for performing wireless section communication with the mobile communication terminal 100 and a Node B 210, a wireless network controller for controlling the Node B ( RNC) 230, connected to the radio network controller 230 and connected to the asynchronous exchange (MSC) 250 and the asynchronous exchange to perform a call exchange to provide a service to the mobile communication terminal 100, the mobile communication service It consists of a core network 270 to provide a core function for.

In a cell of an asynchronous mobile communication system, all non-High Speed Downlink Packet Access (NHS HSDPA) calls and non-High Speed Downlink Packet Access (NHS HSDPA) calls are called. ) Can be serviced

The HSDPA call and the Non HSDPA call assign an Orthogonal Variable Spreading Factor (hereinafter referred to as "OVSF") code, for example, as shown in the following table, and the HSDPA call has up to 15 SF 16 codes. Allocate up to.

division 12.2K 64K 128 K 384K HSDPA SF 128 32 16 8 16

The radio network controller 230 allocates an OVSF code when a call is set up in an asynchronous mobile communication system, and reassigns an OVSF 16 code when an HSDPA call is received in a situation where an OVSF code is used in a random tree during non-HSDPA. If this is not enough, reassign the OVSF code with the following algorithm. Non HSDPA means all connections that are not HSDPA.

First, the wireless network controller 230 does not perform a reassignment procedure for a tree allocated with OVSF 8 codes or more (SF = 8, SF = 4), because the OVSF for HSDPA is performed even if code reassignment is performed. It cannot be allocated by code.

Secondly, the wireless network controller 230 rearranges the OVSF codes with the same size (tree) for OVSF codes using less than OVSF 16 codes (SF = 32 to SF = 512) allocated to Non HSDPA calls. In this case, as shown in FIGS. 5 and 6, the wireless network controller 230 may be used as an OVSF code for HSDPA because it is not randomly distributed (eg, randomly distributed) in order to minimize code relocation. Code) is not rearranged. To describe the relocation procedure in more detail, the wireless network controller 230 reassigns the code from the higher code to the lower code such as OVSF 32 → OVSF 64 → OVSF 128 → OVSF 256 → OVSF 512 in the code relocation. After reassigning the code, it is determined whether the OVSF 16 code for HSDPA is more than the preset standard, and it is determined whether there is enough OVSF 16 code that can be allocated for HSDPA. Stop the reassignment procedure and continue to reassign the code if not enough.

Third, the wireless network controller 230 checks whether the number of OVSF 16 codes for HSDPA is allocated as much as a predetermined number of codes when the system is operating, and if the number of codes is assigned as a preset number, the remaining OVSF codes are designated as Non HSDPA. Assign to call. This is to secure the OVSF code for HSDPA in the system.

Fourthly, the wireless network controller 230 allocates the OVSF code to the Non HSDPA call first and the rest to the HSDPA call during system operation. At this time, when the code resource to be allocated to the Non HSDPA call is insufficient, the radio network controller 230 releases the code resource allocated to the HSDPA call and assigns it to the Non HSDPA call.

Fifthly, the wireless network controller 230 allocates an OVSF code to an HSDPA call first, and allocates the rest to a non-HSDPA call.

7 is a flowchart illustrating a method for allocating OVSF code resources according to the present invention.

First, the wireless network controller 210 allocates an OVSF 16 code when an HSDPA call is received in a situation in which an OVSF code is used in a random tree during non-HSDPA service. In step 210, the OVSF code change report is transmitted (Radio Link Reconfiguration Prepare).

Here, the method for reassigning the OVSF code by the radio network controller 230 can be classified into five major parts as follows.

First, the wireless network controller 230 does not perform a reassignment procedure for a tree allocated with an OVSF 8 code or more (SF = 8, SF = 4), because the HSDPA is performed even if the code reassignment is performed. This is because the OVSF code is not allocated.

Secondly, the wireless network controller 230 rearranges the OVSF codes with the same size (tree) for OVSF codes using less than OVSF 16 codes (SF = 32 to SF = 512) allocated to Non HSDPA calls. In this case, as shown in FIGS. 5 and 6, the wireless network controller 230 does not need to be relocated to minimize code relocation (for example, codes that are not randomly distributed and can be used as OVSF codes for HSDPA). ) Does not relocate. To describe the relocation procedure in more detail, the wireless network controller 230 reassigns the code from the higher code to the lower code such as OVSF 32 → OVSF 64 → OVSF 128 → OVSF 256 → OVSF 512 in the code relocation. After reassigning the code, it is determined whether the OVSF 16 code for HSDPA is more than the preset standard, and it is determined whether there is enough OVSF 16 code that can be allocated for HSDPA. Stop the reassignment procedure and continue to reassign the code if not enough.

Third, the wireless network controller 230 checks whether the number of OVSF 16 codes for HSDPA is allocated as much as a predetermined number of codes when the system is operating, and if the number of codes is assigned as a preset number, the remaining OVSF codes are designated as Non HSDPA. Assign to call. This is to secure the OVSF code for HSDPA in the system.

Fourthly, the wireless network controller 230 allocates the OVSF code to the Non HSDPA call first and the rest to the HSDPA call during system operation. At this time, when the code resource to be allocated to the Non HSDPA call is insufficient, the radio network controller 230 releases the code resource allocated to the HSDPA call and assigns it to the Non HSDPA call.

Fifthly, the wireless network controller 230 allocates an OVSF code to an HSDPA call first, and allocates the rest to a non-HSDPA call.

Subsequently, when the radio network controller 230 receives the code relocation ready message transmitted from the Node B 210 (Radio Link Reconfiguration Ready) (S103), the OVSF code change command including the reassigned OVSF code information in step S101 is performed. The message is transmitted to the Node B 210 and the mobile communication terminal 100 (Radio Link Reconfiguration Commit, Physical Channel Reconfiguration) (S105 and S107).

Thereafter, the wireless network controller 230 receives the OVSF code change result report message transmitted from the mobile communication terminal 100 (Physical Channel Reconfiguration Complete) (S109).

Thus, those skilled in the art will appreciate that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the embodiments described above are to be considered in all respects only as illustrative and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

As described above, the method for allocating an OVSF code resource in the asynchronous mobile communication system of the present invention can efficiently allocate the OVSF code during HSDPA service, thereby improving the data transmission speed supported by the cell, and HSDPA call and Non HSDPA. Manage calls efficiently.

Claims (7)

An orthogonal variable spreading coefficient code resource allocation method in an asynchronous mobile communication system, When a fast forward packet access (HSDPA) call is introduced, an orthogonal variable spreading factor code using less than 16 of a plurality of orthogonal variable spreading factor (OVSF) codes allocated to all access (Non HSDPA) calls except the fast forward packet access is the same size. Reallocating with a code of; / RTI &gt; After reassigning the orthogonal variable spreading code to a code of the same size, Checking whether an orthogonal variable spreading coefficient 16 code for fast forward packet access is greater than or equal to a preset reference; And Stopping the code reassignment procedure if the check result is greater than or equal to a preset criterion; Orthogonal variable spreading coefficient code resource allocation method in an asynchronous mobile communication system comprising a. The method of claim 1, Reassigning the orthogonal variable spreading coefficient code to a code of the same size, Orthogonal variable spreading coefficient code resource allocation method in an asynchronous mobile communication system, characterized in that the code is reallocated from the higher code to the lower code. delete delete delete delete delete

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