KR100212484B1 - The initialization method for tester of mobile communication network - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for initializing a mobile communication network simulator, wherein a simulator for evaluating the quality of service of a code division multiple access (CDMA) mobile communication network is called a link budget. The present invention relates to a method for initializing a mobile communication network simulator that can be efficiently initialized using a standardized plot method.

Description

Initialization method of mobile network simulator

The present invention relates to a method for initializing a mobile communication network simulator. In particular, a simulator for evaluating the service quality of a code division multiple access (CDMA) mobile communication network using a standardized diagram method called a link budget is used. The present invention relates to a method for initializing a mobile communication network simulator which can be initialized efficiently. In order to evaluate service quality and capacity, which are performance indicators of CDMA mobile communication network, interference amount should be evaluated first. The amount of interference is a necessary factor for evaluating shadowed areas, callable areas, etc. in a wireless communication network. The amount of interference is a signal-to-noise ratio, which is inseparably related to bit energy per noise spectral density (Eb / No) and bit error rate or frame error rate. In order to maintain a constant signal-to-interference ratio (SIR), each mobile station controls its transmission power. Since the transmission signals of the mobile stations interfere with each other, power control to prevent this is repeatedly performed. Therefore, in order to converge the target signal-to-interference ratio (SIR) that the CDMA wireless network simulator wants to evaluate, it starts from one mobile station without the interference signal and reaches the target signal-to-interference ratio (SIR) or reaches the target loading. The number of mobile stations must be generated one by one until the end of the year. Therefore, it takes a long time for the state of the simulator to transition to the situation to be analyzed.

Accordingly, an object of the present invention is to provide a method for initializing a mobile communication network simulator which can solve the above-mentioned disadvantages by using a standardized diagram method called a link budget.

The present invention for achieving the above object is a first step of selecting the base station position and the standardized value to be tested, and the second step of standardizing the number of mobile stations according to the arrangement of the mobile station to be tested from the first step And a third step of performing a link budget analysis by applying the normalized variables from the second step, and determining an initial base station traffic power and a mobile station transmission power through the link budget analysis from the third step. In step 4 and step 4, an environment that meets the conditions of adjusting the radius of the cell, adjusting the number of mobile stations, and the test conditions by changing the base station pilot power may be generated. And a fifth step of repeating the output until the output becomes a steady state, wherein the initial base station of the fourth step Traffic power and mobile station transmit power are determined from the first budget determining the average transmit power per forward traffic channel from the link budget analysis and mobile station deployment procedure, the second step of calculating the total amount of forward interference from the first step, and the second step from the second step. A third step of calculating a mobile station reception Eb / No, and a fourth step of determining whether the calculated mobile station reception Eb / No is a required value from the third step and returning to the first step if it is not a required value; And a fifth step of determining the mobile station transmission power through open circuit power control when the calculated mobile station reception Eb / No from the fourth step is a required value, and transmitting the mobile station through closed circuit power control from the fifth step. A sixth step of determining power, a seventh step of determining total mobile station transmission power from the sixth step, and a total amount of backward interference from the seventh step. The eighth step of calculating, the ninth step of determining the base station reception Eb / No from the eighth step, and after determining whether the calculated base station reception Eb / No from the ninth step is the required value is required If not, the method returns to the sixth step, and if it is a required value, it comprises the tenth step of proceeding to the ERP_tch and P_mobile stesdy state routines.

1 is a flow chart for explaining the initialization procedure of the simulator.

2 is a flowchart for explaining an initial base station traffic power and mobile station transmit power determination procedure.

3 is a flowchart illustrating a steady state determination procedure of base station transmit traffic power and mobile station transmit power.

4 is a graph illustrating a change in the number of mobile stations in a wireless network over a program execution time.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention. 1 is a flow chart for explaining the initialization procedure of the simulator, first proceeding from the start step to step (1) to select the location of the base station that meets the test conditions, and then to step (2), the link budget for the deployment of the mobile station. Normalize the interpretation (step (3)). One example of the normalization method is to take a median value for each variable such as the radius of the base station and the number of mobile stations in each cell. In step (4), through the link budget analysis of step (3), pilot power, power for each traffic channel of the initial base station, etc. are set, and the process proceeds to step (5) to adjust the radius of the cell by changing the pilot power of the base station, Adjust the number of mobile stations and create an environment that meets the original test conditions. Repeat this until the output of the simulator is steady-state. As described above, when the simulator is in a steady state under the desired initial conditions, the main procedure of the simulation is started by the actual traffic model and the mobility model. This will be explained in each step as follows.

Step (1) The base station to be tested selects a position and a normalized value.

Step (2) Normalize the number of mobile stations according to the arrangement of the mobile stations to be tested (cell loading).

Step (3) The link budget analysis is performed by applying each of the normalized variables. Here, the link budget analysis method will be described in the description of FIG. 2.

Step (4) Determine initial base station traffic power and mobile station transmit power through the link budget analysis.

Step (5) Create an environment that meets the test conditions, such as adjusting the radius of the cell, adjusting the number of mobile stations, and testing conditions by changing the pilot power of the base station. Repeat this until you are done.

Step (6) As the start of the simulation main procedure, it is determined whether a new call is generated according to the traffic model.

Step (7) When a new call is generated from step (6), the call connection procedure is performed.

Step 8 It is checked whether the call is blocked due to radio resources or the like during the call connection procedure, and if it is confirmed that the call is blocked, it returns to the step (6).

Step 9 If no new call is generated from step (6) or if the call connection is confirmed from step (8), soft handoff and power control is performed on the connected call.

Step 10 After checking whether the call is cut from step 9, if the call is not cut, the process returns to step 9 above.

2 is a flowchart for explaining an initial base station traffic power and a mobile station transmit power determination procedure. Step 11 determines an average transmit power per forward traffic channel from the link budget analysis and mobile station placement procedure by using Equation 1 below.

Step 12 A total amount of forward interference is calculated using Equations 2 to 7 below.

Step 13 Calculate the mobile station reception Eb / No using Equation 8 below.

Step 14 Determines whether the calculated mobile station reception Eb / No is a required value and returns to step 11 if it is not the required value.

Step 15 Determine mobile station transmit power through open circuit power control.

Step 16 Determine the mobile station transmit power via closed circuit power control.

Step (17) Using Equation 9 below, determine the total mobile station transmit power.

Step 18 The total backward interference amount is calculated by using Equations 10 to 13.

Step 19 The base station reception Eb / No is determined using the result of step 18 and Equations 14 and 15 below.

Step 20 After determining whether the calculated base station reception Eb / No is the required value, if not the required value, returns to the step 16, and if it is the required value, proceeds to the ERP＿tch and P_mobile steady state routines. Wherein step (11) to step (14) is a procedure for determining the initial base station transmission traffic channel power and the mobile station reception power through the link budget analysis, and from step 15 to step 20 also performs link budget analysis Is a procedure for determining an initial mobile station transmit power, a base station receive traffic channel power, and a reverse interference amount. 3 is a flowchart illustrating a steady state determination procedure of base station transmit traffic power and mobile station transmit power. FIG. 3 is a diagram illustrating a cell radius adjustment, mobile station number adjustment, and an environment suitable for original test conditions. While it is made, it is repeated until the output of the simulator such as base station transmission traffic power and mobile station transmission power becomes steady state.

Step 21: From the initial value setup procedure, base station placement and mobile stations in a condition normalized to the link budget calculation are actually generated by the simulator.

Step 22 After confirming that the environment suitable for the original test conditions is provided, if the test conditions are met, proceed to step 31 to start the simulation.

Step 23 If the test conditions are not met from the step 22, the procedure of adjusting the number of mobile stations per cell and adjusting the radius of the cell by changing the pilot power of the base station is performed.

Step 24 Calculate the received power of the mobile station meeting the new condition.

Step 25 Calculate the amount of forward interference tailored to the new condition.

Step 26, calculate the mobile station reception Eb / No.

Step 27 Calculate the mobile station transmit power.

Step 28 Calculate the base station received power.

Step 29 Calculate the amount of backward interference that satisfies the new condition.

Step 30 calculate the base station reception Eb / No.

In a CDMA system, each mobile station performs its own transmit power control, and the power signals are repeatedly performed because the transmission signals of the mobile stations interfere with each other. Therefore, when making or simulating the simulator for performance evaluation of CDMA wireless network, it is necessary to start from one mobile station without interference signal and approach the test conditions such as the number and load of mobile stations. For reference, FIG. 4 is a graph illustrating a process of stabilizing the test environment according to the number of mobile stations. The horizontal side shows the program execution time, and the vertical axis shows the number of mobile stations in the network. Here, the variable Tsteady is a time taken from one mobile station to become the average number of mobile stations (Nusr) of the target wireless communication network. In addition, Tlink is a time required to be the average number of mobile stations (Nusr) of the wireless communication network when applying the method of the present invention. Therefore, the time saving effect is as much as Tsteady-Tlink. As an experimental example, the time required for the average number of mobile stations (Nusr) in the wireless network to be 500 starting from one mobile station is the ULTRA SPARC workstation computer. It takes about three days or more, and depending on the situation, this time can be reduced to less than one day.

As described above, according to the present invention, the efficiency of the work can be improved by efficiently performing initialization using a standardized diagram method called a link budget when manufacturing a CDMA wireless network simulator. For reference, the following example can be shown to prove the effect that can be obtained when using the simulation method initialization method according to the present invention. As an example, when evaluating the quality of service of a wireless communication network in which an arbitrary number of base stations is 25 and an average number of mobile stations per base station is 50 (at this time, the calculation unit of the simulator is assumed to be 1.25 msec. For the newly increased mobile station, the time until the SIR is balanced through the call control procedure in the actual system through the power control procedure for the newly increased mobile station. Assuming t, the number of calculations (P) that the simulator should perform during this time is P t / 1.25 msec. here Assuming t is 1 second, P It takes 800 calculations, or 800 steps per second. In other words, this value P is the number of steps to be performed by the simulator per second when the number of mobile stations increases by one. Thus the total number of mobile stations (25 50 The total number of calculation steps required for 1250) is (1250 mobile stations) Is P, here P Substituting 800 gives 1250 per second 800 10 ⁶ calculation steps are calculated. For example, in this state, the calculation for 5 minutes is (10 ⁶ times / second). (300 seconds) 3 10 ⁸ calculation steps are required. Depending on the workstation computer running the simulator, this calculation is very expensive. Therefore, in consideration of this point, the present invention provides an effective simulation method for any simulator for evaluating CDMA service quality.

Claims (8)

A method for initializing a mobile communication network simulator, comprising: a first step of selecting a base station location and a standardized value to be tested; a second step of standardizing the number of mobile stations to be tested from the first step; A third step of performing link budget analysis by applying each of the normalized variables from step 2, and a fourth step of determining initial base station traffic power and mobile station transmission power through the link budget analysis from the third step; And a fifth step of repeating the fourth step from the fourth step until the output of the simulator is steady, such as adjusting the cell radius, adjusting the number of mobile stations, and transmitting power of the mobile station. Characterized in that the initialization method of the mobile communication network simulator. The method of claim 1, wherein the initial traffic power and the mobile station transmit power of the fourth step are determined by a first step of determining an average transmit power per forward traffic channel from a link budget analysis and mobile station arrangement procedure, and the total amount of forward interference from the first step. A second step of calculating, a third step of calculating a mobile station reception Eb / No from the second step, and determining whether the calculated mobile station reception Eb / No from the third step is a required value and the required value is If not, the fourth step of returning to the first step, and the fifth step of determining the mobile station transmit power through the open circuit power control when the calculated mobile station reception Eb / No from the fourth step is a required value, and A sixth step of determining mobile station transmit power through closed circuit power control from a fifth step; a seventh step of determining total mobile station transmit power from the sixth step; An eighth step of calculating the total reverse interference amount from step 7, a ninth step of determining the base station reception Eb / No from the eighth step, and whether the calculated base station reception Eb / No from the ninth step is a required value; If it is not the required value and then return to the sixth step and if the required value is the initialization method of the mobile communication network simulator, characterized in that it comprises a tenth step to proceed to the ERP_tch and P_mobile steady state routines. 3. The method of claim 2, wherein the average transmit power per forward traffic channel of the first step is determined by the following equation. Average transmit power per channel of forward traffic (Total Traffic Channel Power) / (Number of Mobile Stations * Voice Activation Rate) The method of claim 2, wherein the total amount of forward interference in the second step is calculated by Equation 1 to Equation 6 below. Total base station power received by the mobile station Base Station Transmit Power + Average Propagation Attenuation + Interval Average Fading Tolerance + Mobile Station Antenna Gain ----- [Equation 1] Received Power Per Traffic Channel Base station transmit power per traffic channel + average propagation attenuation + interval average fading tolerance + mobile station antenna gain ----- [Equation 2] Mobile station received traffic channel Eb Received Power / Data Rate per Traffic Channel ----- [Equation 3] Other user interference amount (Average transmit power per traffic channel-receive power per traffic channel) / Spread Bandwidth ----- [Equation 4] Other cell interference Other mobile station interference amount / (1 / forward frequency reuse rate-1) ----- [Equation 5] Total forward interference Other user interference amount + other cell interference amount ----- [Equation 6] 3. The method of claim 2, wherein the mobile station reception Eb / No in the third step is calculated by the following equation. Mobile station receive Eb / No Mobile Receive Traffic Channel Eb / (Total Forward Interference + Thermal Noise Power Density) 3. The method of claim 2, wherein the total mobile station transmit power of the seventh step is determined by the following equation. Mobile station transmit power Mobile station transmit power through closed circuit power control + Mobile station transmit power through open circuit power control + Mobile station antenna gain The method of claim 2, wherein the total amount of backward interference in step 8 is calculated by Equation 1 to Equation 4 below. Received Signal Power per Base Station Subscriber Mobile station transmit power + average propagation attenuation + interval average fading tolerance + base station antenna gain ----- [Equation 1] Interference with other mobile stations in same cell Received signal power / bandwidth per base station subscriber (number of mobile stations-1) * Voice activation rate ----- [Equation 2] Mobile station interference in other cells Interference with other mobile stations in the same cell * (1 / reverse frequency reuse rate -1) ----- [Equation 3] Total reverse interference Interference Amount of Other Mobile Stations in the Same Cell + Interference Amount of Mobile Stations in Other Cells ----- [Equation 4] The method of claim 2, wherein the base station reception Eb / No in step 9 is determined by Equation 1 and Equation 2 below. Base Station Received Traffic Channel Eb Received signal power / data rate per base station subscriber ----- [Equation 1] Base Station Receive Eb / No Base Station Receive Traffic Channel Eb / (Total Reverse Interference Amount + Thermal Noise Power Density) ----- [Equation 2]