KR20050067930A - Method for assigning selector processor for call setup in radio network controller of wcdma telecommunication system - Google Patents

Abstract

The present invention relates to a method for allocating a selector processor for call setup in a WCDMA-based mobile communication system having a plurality of selector processors in a base station controller. And assigning a selector processor with the lowest call blocking probability for the call.

Description

Method for assigning selector processor for call setup in radio network controller of WCDMA telecommunication system

The present invention relates to a method for allocating a selector processor for call setup in a WCDMA mobile communication system having a plurality of selector processors in a radio network controller (RRC).

First, a general selector processor configuration of a base station controller will be described with reference to FIG. 1.

1 is a block diagram showing a general selector processor configuration of a base station controller. As shown in FIG. 1, the C selector card 11 is mounted in the base station controller, and the P processors 111 are mounted in each selector card. Accordingly, C * P = M selector processors 111 exist in one base station controller. In addition, each selector processor is composed of N channel elements (CE) 102. Here, 1 CE is a logical unit indicating the processing capacity of the processor that can accommodate one voice call. As a result, the base station controller equipped with M selectors provides M * N channel elements.

In the base station controller having the configuration of the selector processor described above, a typical division method is one of a method in which a specific selector processor is allocated for the new call setup when the call setup request of the mobile station is requested. According to this method, the load due to call establishment is not even concentrated in a specific selector processor of the base station controller, but is evenly distributed throughout the selector processor.

However, the equal division method has the following problems, which will be described with reference to FIG. 2.

2 is a block diagram illustrating an example in which selector processors of a base station controller are allocated for call setup according to a conventional equalization method. As shown in FIG. 2, it is assumed that all M selector processors 200 mounted to one base station controller are already allocated and used N-1 CEs 201 for call processing at any point in time. That is, each selector processor 200 has one unassigned CE, and there are M unassigned CEs in the base station control station as a whole.

In such a situation, if a call requiring only one CE needs to be newly set up, such as a voice telephone or a short message service, which takes an absolutely large weight in a second generation CDMA mobile telephone network such as IS-95A / B, the one Any one of the selector processors with unassigned CE may be allocated for the call.

However, with the introduction of the 3rd generation WCDMA mobile telephone network and services requiring wide bandwidth such as video telephony, the base station controller needs to allocate several CEs in some cases in order to establish one call. It happened. Therefore, considering the case where a new call A that requires M CEs is set, there are M unallocated CEs in the base station controller as a whole, but the new call A must be blocked. That is, even if the unassigned CE held by the base station controller is the same as the CE required for call setup at any point in time, the unassigned CE is distributed among several selector processors, so that the call setup request of the mobile station cannot be accepted. It can be.

Meanwhile, in the WDCMA system, when a call is requested for a new call, a base station controller may check only a service class to which the corresponding call belongs. In other words, it can only check whether the call is a voice call, a streaming call, an interactive call, or a background service call, and although the CE occupancy rate of the selector processor varies depending on the transmission speed of the call, the call rate required for providing a normal service is required. Is unknown. The number of CEs to be allocated for the new call can be checked after receiving the RAB (Radio Access Bearer) parameter from the upper network after the RRC connection is set up. That is, the base station controller should determine which selector processor should be allocated to the call using only information on available resources for each selector processor of the base station controller in a situation where the resource (ie, CE) occupancy of the selector processor of the new call is unknown. do. For example, suppose that the mobile station requires the setup of a call of B, which occupies 10 CEs, so that the base station controller assigns call B to selector processor S with 5 available CEs remaining. As mentioned above, the base station controller is sufficiently capable of not knowing in advance that call B needs 10 CEs of the selector processor resources when allocating the selector processor. After receiving the RAB parameter for call B, the base station controller will know that call B needs 10 CEs. At this point, if there is no other selector processor with more than 10 unassigned CEs, the base station controller is forced to block call B. However, if there are other selector processors with 10 or more unassigned CEs, then the base station controller takes the following actions to ensure that call B is assigned to the other selector processor. Although call B may not be blocked by follow-up, this call handling procedure is an important factor in delaying call setup.

The present invention has been made to solve the problems of the prior art as described above, and improves the selector protector allocation method when the call setup request of the mobile station in the WCDMA mobile communication system to effectively use the selector protectors to lower the call blocking rate and also The purpose is to reduce the delay of the setting.

In order to achieve the above object, the present invention provides a method for allocating a selector processor for call setup in a WCDMA-based mobile communication system having a plurality of selector processors in a base station controller. A method for allocating a selector processor for call establishment in a WCDMA-based mobile communication system, comprising: obtaining a call blocking probability; and allocating a selector processor having the lowest call blocking probability for the call. to provide.

Hereinafter, a preferred embodiment of the present invention that can realize the above object will be described with reference to FIG.

3 is a flowchart illustrating a method of allocating a selector processor for call setup in a base station controller of a WCDMA mobile communication system according to the present invention.

First, the following symbols are defined to describe the embodiment according to the present invention.

k: arc type (k = 1, ..., K); Call type k determines the transmission rate and CE requirements of the call.

p (k): the ratio of call type k to all call types; The sum of p (k) for all k is one.

r (k): CE occupancy of arc type k

m: each selector processor (m = 1, ..., M) installed in the base station controller

N: Number of CEs provided by one selector processor

s (m): the number of CEs that the selector processor m is using at any time (s (m) is a value between 0 and N, inclusive)

Block_Rate (m): Call block probability expected when assigning a new call to selector processor m.

As described above, the type k of the new call is not known at the time of assigning the selector processor. However, it is assumed that the CE usage s (m) per selector processor, the CE occupancy r (k) per call type, and the generation rate p (k) of the call type k are known.

Based on the above-described symbols and assumptions, a selector processor allocation method for call setup according to the present invention will be described as follows.

First, the call blocking probability Block_Rate (m) is calculated for all m assuming that a new call is allocated to each selector processor in consideration of the ratio p (k) for each call type (32). When the new call is assigned to the selector processor m, the call blocking probability may be calculated by the following algorithm.

k = 1

Block_Rate (m) = 0

Do {

if (r (k)> N-s (m)) then {Block_Rate (m) = Block_Rate (m) + p (k)}

k = k + 1

} while (k K)

Next, a new call is allocated to the selector processor having the smallest call blocking probability Block_Rate (m) value calculated for each selector processor (35). If there are multiple selector processors with the smallest block blocking probability Block_Rate (m), the selector processor with the largest s (m) value (ie, the smallest unallocated CE number N-s (m)) Assign (34).

According to the method of allocating a channel element for a new call setup in a base station controller of a WCDMA mobile communication system according to the present invention, the call blocking rate can be reduced by effectively utilizing a given selector processor in a multimedia mobile communication environment, and the delay time of call setup can be reduced. Can be reduced.

1 is a block diagram showing a general selector processor configuration of a base station controller.

2 is a block diagram illustrating an example in which selector processors of a base station controller are allocated for call setup according to a conventional equalization method.

3 is a flowchart illustrating a method of allocating a selector processor for call setup in a base station controller of a WCDMA mobile communication system according to the present invention.

Claims (3)

A method of allocating a selector processor for call setup in a WCDMA based mobile communication system having a plurality of selector processors in a base station controller, a) obtaining a call blocking probability of the call for each of all the selector processors; And b) allocating a selector processor for the call setup in a WCDMA based mobile communication system comprising assigning a selector processor having the lowest call blocking probability for the call. The method of claim 1, If there are a plurality of selector processors having the lowest call blocking probability in step b), the selector processor having the lowest available channel element among the selector processors is allocated for the call. To assign the selector processor to set up a call on Windows. The method of claim 1, and in step a), the call blocking probability of each call for each of the selector processors is obtained by the following algorithm. k = 1 Block_Rate (m) = 0 Do { if (r (k)> N-s (m)) then {Block_Rate (m) = Block_Rate (m) + p (k)} k = k + 1 } while (k K) Where k is the arc type (k = 1, ..., K), p (k) is the proportion of the arc type k of all the arc types, and r (k) is the CE occupancy of the arc type k, m is each selector processor (m = 1, ..., M) mounted in the base station controller, N is the number of CEs provided by one selector processor, and s (m) is the selector processor m used at any time. Number of CEs in progress (0 s (m) N), and Block_Rate (m) is the expected call blocking probability when assigning a call to the selector processor m.