CN1146173C - Capacity increasing method for CDMA mobile communication system - Google Patents

Abstract

A method for improving the capacity of a code division multiple access mobile communication system, comprising: performing statistics on the current load of the system; triggering dynamic adjustment of system capacity when overload occurs, and reducing the transmission rate of data services; when under load occurs, The transmission rate of the data service is maintained or the adjusted transmission rate of the data service is restored to the value before adjustment. The relationship between the adjusted current transmission rate R and the unadjusted rate R is 2×(1-Q)×R, where Q is the current load percentage. The adjusted data service includes the transmission rate of a certain mobile station user, or the transmission rate of a certain type of data service or a data service with the highest current transmission power.

Description

A Method of Improving the Capacity of Code Division Multiple Access Mobile Communication System

technical field

The present invention relates to a mobile communication system technology, more specifically to a method for improving system capacity in a Code Division Multiple Access (CDMA) mobile communication system.

Background technique

Multiple access interference is the main factor restricting the capacity of direct sequence code division multiple access mobile communication systems, and the direct measure to reduce multiple access interference is to control the source of interference signals - including controlling the transmission power of each base station and each mobile station user, that is, power control , referred to as power control. The basic principles followed by this power control are: on the one hand, it is necessary to meet the requirements of each mobile station user for communication service quality; on the other hand, the transmission power of each mobile station user should be minimized. , it is also feasible to maximize system capacity and optimize system performance.

The services provided by the CDMA mobile communication system include voice services and data services. Correspondingly, the capacity of the CDMA mobile communication system also includes voice service capacity and data service capacity. In the system stipulated by the IS-95 communication standard, the system capacity mainly refers to the voice service capacity, and the main technology to improve the voice service capacity is power control. Therefore, power control is one of the key technologies to improve the capacity of CDMA mobile communication system.

The power control of the CDMA mobile communication system is divided into forward power control and reverse power control. The inner loop power control in the reverse power control refers to: the base station estimates the signal strength from a specific mobile station user, and measures the ratio of the information bit energy of the mobile station user to the interference spectral density (expressed as E _b / I ₀ or Eb/No), and according to whether E _b /I ₀ is lower or higher than the required value, determine whether the power control bit fed back to the mobile station user is "0" or "1", (take "0" indicates that the power needs to be increased, and "1" indicates that the power needs to be reduced), and the mobile station user then increases or decreases the transmission power correspondingly according to the received power control bit, so as to ensure that the E _b / I ₀ (Eb/No) can be maintained at a constant level.

If the power control is not ideal, the actual transmission power will fluctuate by 20%-30%. In the case where the transmission power of the data service itself is already high, such fluctuations are likely to be fatal, because the impact is not only on the data business, and relative to other users, it will undoubtedly become a big source of interference.

Improving the transmission power is a method of existing power control to ensure a certain transmission quality, which is measured by the frame error rate index, but when the mobile station user is at the edge of the cell, or the transmission channel has Deep fading, blindly increasing the transmission power at this time may not be able to meet the requirements, and as mentioned above, the transmission power of high-speed data services is already high, and the corresponding interference is already very large. For users, it is a powerful source of interference, and the consequences are unimaginable.

Another way of thinking about power control is to adjust the load of the cell by adjusting the data transmission rate of user data services, especially by reducing the transmission rate of data services. Reduce system load. This method of adjusting the data service rate is to exchange the system capacity at the cost of sacrificing the rate. However, the existing method of changing the rate is to reduce the rate by multiples, resulting in excessive adjustment or too small adjustment. Larger height changes will cause the system to work unstable.

The purpose of adjusting the data rate is to get a quick response when the communication environment suddenly deteriorates, that is, when the rate changes, in order to maintain a certain quality of service, the user's transmit power will change accordingly.

When the background noise density is N ₀ , the bandwidth is W, the user data rate is R _i , and the user transmission power of the mobile station is P _i , the ratio (Eb/Io) of the information bit energy of the i-th user received by the base station to the interference spectral density is :

$\frac{{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}}}{{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; G</span>}}_{\mathrm{<span\; class="notranslate">\; mi</span>}}{<span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}{<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}<span\; class="notranslate">\; \&NotEqual;</span>\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; J</span>}}{\mathrm{<span\; class="notranslate">\; G</span>}}_{\mathrm{<span\; class="notranslate">\; mj</span>}}{<span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; w</span>}}$

In the formula, G _mi represents the path gain from the i-th mobile station user to the base station m, ∑ _J≠i ^J G _mj represents the transmission power of all J mobile station users except the i-th mobile station user to the first mobile station user The sum of interference generated by i mobile station users.

In order to maintain a certain quality of service, that is, under the condition that the target frame error rate Tar FER remains unchanged, the transmission power before adjustment (P _i /R _i ) and after adjustment (P _i '/R _i ') and data The ratio of transmission rates remains consistent, as shown in the following equation, $\frac{P_i}{R_i}=\frac{P_i^{\&prime;}}{R_i^{\&prime;}},$ Therefore, when the data transmission rate (R) is increased or decreased, the transmission power (P) will also increase or decrease accordingly, that is, there is a proportional relationship between the transmission power and the data transmission rate.

Contents of the invention

The purpose of the present invention is to design a method for improving the capacity of the CDMA mobile communication system, which is to adjust the transmission rate of the corresponding data service in real time and in an appropriate amount according to the current load of the mobile communication system, that is, to adjust its transmission power, so as to maintain Capacity and stability of communication systems.

The technical scheme that realizes the object of the present invention is such: a kind of method that improves the capacity of CDMA mobile communication system, is characterized in that comprising:

Make statistics on the current load of the system; trigger dynamic adjustment of system capacity when overload occurs, and reduce the transmission rate of data services according to the relationship between the current transmission rate and the transmission rate of the original data service before adjustment and the current load percentage; When an underload occurs, the transmission rate of the data service is maintained or the adjusted transmission rate of the data service is restored to the value before adjustment.

The overload means that the statistical current load is greater than or equal to the set system load threshold; the underload means that the statistical current load is smaller than the set system load threshold.

The set system load threshold is 75% of the total designed load capacity of the system.

The transmission rate of the data service includes the transmission rate of the data service of a certain mobile station user, or the transmission rate of a certain type of data service, or the transmission rate of the data service with the highest transmission power currently.

It also includes dynamic adjustment according to the priority sequence of preset data services.

The dynamic adjustment according to the priority order of the preset data services further includes: firstly adjusting the transmission rate of the data service with the lowest priority; when the current load of the statistics is still greater than or equal to the preset system load gate After the time limit, adjust the transmission rate of the data service with the next priority until the transmission rate of the data service with the highest priority.

When reducing the transmission rate of the data service, it also includes reducing its transmission power; and, when restoring the adjusted transmission rate of the data service to the value before adjustment, it also includes increasing its transmission power.

The described reduction of the transmission rate of the data service and its transmission power, and restoring the adjusted transmission rate of the data service to the value before adjustment and increasing its transmission power are controlled by the front-end signal processing subsystem of the mobile station user end. The subsystem, and the data message distribution module of the base station and its base station controller, are completed by controlling the load control module and controlling the power control subsystem in the resource management module.

The above process further includes:

A. The mobile station user terminal measures the received signal quality and generates a measurement report, which is sent to the base station along with the reverse feedback link signal;

B. The base station processes the received reverse signal and sends it to the base station controller;

C. Estimate the ratio of the information bit energy of the mobile station user signal to the interference spectral density by the baseband processing unit in the base station controller, and compare with the threshold value of setting, determine that the power control bit is 0 or 1, and which is sent to the mobile station user;

D. The base station controller continuously detects the system load according to the information reported by the base station, and compares it with the set system load threshold. When the detected system load is greater than the threshold, press R'=2×(1-Q)×R The algorithm adjusts the transmission rate of the current data service, R is the transmission rate of the original data service, and Q is the current load percentage;

E. When the detected system load is less than the set system load threshold, the transmission rate R' of the current data service is maintained or restored to the transmission rate R of the original data service;

F. The user of the mobile station increases or decreases the transmission power correspondingly according to the received power control bits.

Since the CDMA mobile communication system has the characteristics of soft capacity, it adopts handover technologies including hard handover, soft handover, softer handover, etc., to switch the service of overloaded cells to non-overloaded cells, so as to realize the dynamic adjustment of cell capacity. However, the method of the present invention automatically adjusts the transmission rate of data services by making statistics on the load of the cell, that is, when the cell is overloaded, the dynamic adjustment of the cell capacity is triggered, and according to the status of the system load, a certain user is reduced. Or the transmission rate of a certain type of data service or the data service with the highest transmission power. At this time, the transmission power of the user or related service users will also be reduced, so that the total power received by the base station is reduced, and more calls can be accommodated. , to achieve the effect of increasing the system capacity; when the cell is under load, restore the adjusted data rate to the original data rate value, or keep the original data rate value unchanged to enable transmission at a high data rate. Therefore, the method of the present invention is a method for timely and appropriately adjusting the data transmission rate and further adjusting the system capacity according to the current load level of the mobile communication system.

The method of the present invention adjusts the data service transmission rate according to the current load situation, which is a relatively simple and accurate method, and appropriately changes the service data rate within the data rate range allowed by the data service. The method of the present invention adjusts the rate timely and properly according to the current load of the mobile communication system, and the greater the load (load), the greater the range of rate adjustment. For example, when the load is heavy, the transmission rate of a certain user or a certain type of data service or the data service with the highest transmission power is reduced to ensure that more calls are accessed; when the load is small, the data rate is maintained or increased. Adjust back to the original value to increase the transfer rate.

In the reverse inner loop power control, since the inner loop power control time is 800 times per second, the reaction time is very fast, and the time required for adjusting the rate to produce capacity changes can be ignored.

When the data service uses the auxiliary channel (SCH), its rate is generally greater than or equal to 19.2kbps, and the higher the rate, the greater the adjusted reduced power or interference range, and the better the adjusted effect. However, the present invention adjusts the rate only when the rate of the data service is greater than or equal to 38.4kbps, so as to improve the stability and capacity of the system.

Description of drawings

Figure 1 is a schematic diagram of the model structure of the cellular mobile communication system.

Fig. 2 is a block diagram of the first embodiment of power adjustment in the present invention.

Fig. 3 is a flow chart of the second embodiment of power adjustment in the present invention.

Fig. 4 is a schematic diagram of the structure of the user's mobile station in the mobile communication system.

Fig. 5 is a schematic structural diagram of a base station controller in a mobile communication system.

Detailed ways

The technical solutions of the present invention will be further described below in conjunction with the embodiments and accompanying drawings.

Referring to Fig. 1, it shows a model of a cellular mobile communication system, including a mobile station user end, a base station (BTS) and a base station controller (BSC). The processing system in the base station controller handles the call volume of the cellular mobile communication system. The base station controller receives calls from the mobile station user end and sends calls to the mobile station user end through a series of base stations. A base station communicates with many mobile station users, and a base station controller communicates with many base stations.

Referring to FIG. 2 , it is a flowchart of an embodiment of the method of the present invention.

Step 21, the system continuously detects the load situation of the system (or cell);

Step 22, comparing the detected system (or cell) load with a preset threshold value, the preset threshold value is the threshold value Th that triggers the dynamic adjustment of the data rate, which can be determined according to the actual situation of the system, generally can be It is set as 0.75 (or above 0.75) of the maximum capacity of the system, because the system generally requires the ratio of the total noise plus interference power I ₀ received by the base station to the background noise N ₀ to be limited, and then the bandwidth W is used for normalization , can be expressed as I ₀ W/N ₀ W is less than 1/η, η is less than 1, and the typical value of η is 0.1 to 0.25, corresponding to the power ratio I ₀ /N ₀ =6dB to 10dB, when I ₀ /N ₀ When =6dB, the load percentage of the system is 75%, that is, 75% of the maximum capacity, which is used as the threshold value Th for triggering the dynamic adjustment of the data rate in the present invention.

Step 24, if the current load of the detected system (or cell) is greater than or equal to the threshold value Th, the data service is transmitted at a new rate R', that is, the transmission rate of the data service is adjusted from R to R', and R'= 2×(1-Q)×R, where R is the transmission rate of the original data service, and Q is the current load percentage;

Step 23, if the current load of the detected system (or cell) is lower than the threshold value Th, keep the rate of the data service unchanged, that is, maintain or restore the original transmission rate R before the adjustment of the data service, which can be expressed as: data service rate =R;

Step 25, return to the system and execute step 21 again.

The adjustment idea embodied in this embodiment is: the system first sets the adjustment threshold, and when the actual load of the system is greater than or equal to the threshold, it will adjust the rate of a certain user data service or adjust the rate of a certain type of service according to the current load percentage Q. The rate of the data service or adjust the rate of the data service with the highest transmission power (of course, the rate of the data service with special requirements may not be adjusted). The greater the load, the greater the degree of rate adjustment, which is beneficial to increase the stability of the system and the capacity of the system; and if the actual load (load percentage) of the system is less than this threshold, the data rate of the original data service will be maintained or the data The data rate of the service is restored to the data service rate before adjustment.

Referring to FIG. 3 , it is a process flow of another embodiment of the method of the present invention.

Step 31, the system continuously detects the load situation of the system (or cell);

Step 32, comparing the detected system (or cell) load with a preset threshold value, the preset threshold value is the threshold value Th that triggers the dynamic adjustment of the data rate, which can be determined according to the actual situation of the system, generally can be Set as 0.75 of the maximum capacity of the system (or above 0.75);

Steps 34 to 37, if the current load is greater than or equal to the threshold value Th, let the data service be transmitted at the new rate R', that is, adjust the transmission rate of the data service from R to R', but the adjustment is according to the preset It is carried out according to the priority of the data service, that is, the priority of the data service is preset by the system. If it is taken as three levels, the order of the levels is: data service 1 "data service 2)" data service 3. When adjusting, the lowest level should be adjusted first After adjusting the transmission rate of the lowest-level data service 3, if the current load of the system is still greater than or equal to the threshold value Th, then further adjust the data service 2, after adjusting the transmission rate of the middle-level data service 2 After the transmission rate, if the current load of the system is still greater than or equal to the threshold value Th, the transmission rate of the highest-level data service 1 is further adjusted at last, and R' in the above adjustment process is also according to the formula R'=2×(1-Q )×R, where R is the transmission rate of the original data service, and Q is the current load percentage;

Step 38, return to the system and execute step 31 again.

Step 33, when executing step 32, if the current load of the detected system (cell) is lower than the maximum capacity Th, keep the rate of data service unchanged, that is, maintain the current data service transmission rate R, or in steps 34 to 37 , after adjusting the transmission rate of the data services of the third and second grades, if the current load (load percentage) Q of the system is less than the threshold value Th, the system will restore the data rate of the data services to the rate before adjustment, Can be expressed as: data service rate = R.

The adjustment idea reflected in this embodiment is: the system first sets the adjustment threshold, and when the actual load of the system is greater than or equal to this threshold, it will start from the lowest to the highest according to the size of the current load percentage Q and according to the preset data service priority. The advanced sequence adjusts the rate of a certain user data service or a certain type of data service or adjusts the rate of the data service with the highest transmission power (of course, the rate of the data service with special requirements can not be adjusted), such as first adjusting The data rate of the lowest-priority data service, when the data rate of the lowest-level data service is adjusted to the minimum level set by the system, if the system is still overloaded, then adjust the rate of the second-priority data service in turn, Finally, the rate of the data service with the highest priority is adjusted. When the system only sets a threshold and the load is less than this threshold, the adjusted data rate will be restored, and the original data service rate will be restored.

The core technology of the inventive method is: the load threshold is set by the system; when the current load exceeds the threshold, the adjustment (reduction) of the data service transmission rate is carried out; when the current load is less than the threshold, the original transmission rate of the data service is kept constant Change or restore the adjusted data service transmission rate to the original data service rate.

The adjustment method of the present invention can be carried out only for the data service of a certain mobile station user, can also be carried out for a certain type of data service in the system (cell), or even for the data service with the largest current transmission power, depending on the needs of the system, For some data services with special requirements, no adjustment is required.

Referring to FIG. 4 , the mobile station user end includes an antenna subsystem 41 , a multiplexing unit 42 , a front-end signal processing subsystem 43 , a power control subsystem 44 and a service subsystem 45 .

Referring to Fig. 5, the base station controller includes a frame recovery module 51, a data message distribution module 52, a power control subsystem 53, a resource management module 54 and a service subsystem module 55, wherein 541 is a load control module in the resource management module 54 module.

Referring to Fig. 4 and Fig. 5 in conjunction, the process of adjusting the data service rate and its transmission power according to the method of the present invention is further described.

1. The antenna subsystem 41 of a mobile station user end receives the pilot signal from the forward link of the base station, and sends it to the multiplexing unit 42, and the multiplexing unit 42 separates the forward link signal on the forward frequency point and sends it to To the front-end signal processing subsystem 43, the forward link signal is also sent to the power control subsystem 44 through the front-end signal processing subsystem 43, and the power control subsystem 44 measures the received signal quality, generates a measurement report, and measures The report is sent to the base station through the multiplexing unit 42 and through the antenna subsystem 41 along with the reverse feedback link signal;

2. The antenna subsystem of the base station receives the signal from the reverse feedback link of the mobile station user at the reverse frequency point, and sends the signal to the multiplexing unit, and the multiplexing unit sends the received reverse signal to the reverse feedback link Perform necessary front-end amplification, baseband processing and frame processing to the information processing subsystem, and then send the message to the base station controller, and the baseband processing unit in the base station controller estimates the information bit energy and interference spectral density of the user signal of the mobile station The ratio (Eb/Io), and compared with the threshold value of Eb/Io set, according to the comparison result, determine the power control bit (0 or 1), and then send it to the mobile station user, mobile station The user then increases or decreases the transmission power correspondingly according to the received power control bit;

3. In the above-mentioned power control process, the base station controller reaches the data message distribution module 52 through frame recovery (51), and the data message distribution module 52 is divided into three routes and output to the power control subsystem 53, the resource management module 54 and the service sub-system System 55, the load control module 541 in the resource management module 54 continuously detects the status of the system (cell) load according to the information reported by the base station;

4. Compare the detected system (or cell) load with a set system maximum load threshold, when the detected system (or cell) load is greater than the set threshold, that is, when the system (or cell) is overloaded, follow this The inventive algorithm modifies and adjusts the data service transmission rate of the mobile station user in the resource management module 54 or the transmission rate of a certain type of data service or the transmission rate of the data service with the largest current transmission power, so that the adjusted rate R' is ; 2×(1-Q)×R, R is the original transmission rate of the data service;

5. The base station controller sends a message to the base station, and obtains the Eb/Io of the received user signal through the frame processing of the baseband processing unit, and compares it with the set Eb/Io threshold value. When the Eb/Io of the received user signal is greater than When the Eb/Io threshold is set, the power control bit sent to the mobile station user is set to '1', and the mobile station user will automatically reduce the transmission power according to the power control bit '1';

6. When the detected system (community) load is less than the threshold set, that is, the system (community) is in a light load state (underload), just modify and adjust the mobile station user in the resource management module 54 according to the algorithm of the present invention The transmission rate of the data service or the transmission rate of a certain type of data service or the transmission rate of the data service with the highest transmission power at present, so that the adjusted rate R' is maintained or restored to the transmission rate R of the original data service;

7. The base station controller sends a message to the base station, and obtains the Eb/Io of the received user signal through the frame processing of the baseband processing unit, and compares it with the set Eb/Io threshold value. When the Eb/Io of the received user signal is less than When the Eb/Io threshold is set, the power control bit sent to the mobile station user is set to '0', and the mobile station user will automatically increase the transmission power according to the power control bit '0'.

The method for increasing the system capacity of the present invention is a method for adjusting the transmission rate of data services according to the system load; the method of the present invention utilizes the technology of adjusting the soft capacity of the code division multiple access mobile communication system, and makes improvements on the basis of this technology .

The method of the invention is simulated in the CDMA2000 mobile communication system, adopts ready-made hardware and software designed according to the idea of the invention, and achieves expected effects.

Claims (10)

1. method that improves the CDMA mobile communication systems capacity is characterized in that comprising:

Present load situation to system is added up; The dynamic adjustment of triggering system capacity when overload occurring is by current transmission rate and the transmission rate of the former data service before adjusting and reduce the transmission rate of data service when the relation between preload percentage; When underload occurring, keep the transmission rate of data service or the transmission rate of adjusted data service is reverted to value before adjusting.

2. a kind of method that improves the CDMA mobile communication systems capacity according to claim 1 is characterized in that: described overload is meant that the present load of statistics is more than or equal to set system load thresholding; Described underload is meant that the present load of statistics is less than set system load thresholding.

3. a kind of method that improves the CDMA mobile communication systems capacity according to claim 2 is characterized in that: described set system load thresholding is 75% of a system design load total capacity.

4. a kind of method that improves the CDMA mobile communication systems capacity according to claim 1, it is characterized in that: the transmission rate of described data service, the transmission rate that comprises the data service of a certain user of mobile station, the transmission rate of perhaps a certain class data service, the perhaps transmission rate of the data service of current transmit power maximum.

5. a kind of method that improves the CDMA mobile communication systems capacity according to claim 1, it is characterized in that: the transmission rate of the former data service before described current transmission rate and the adjustment reaches when the relation between preload percentage, be R '=2 * (1-Q) * R, R ' is current transmission rate, R is the transmission rate of the former data service before adjusting, and Q is for working as preload percentage.

6. a kind of method that improves the CDMA mobile communication systems capacity according to claim 1 is characterized in that: also comprise by the priority orders of predefined data service and dynamically adjusting.

7. a kind of method that improves the CDMA mobile communication systems capacity according to claim 6, it is characterized in that described priority orders by predefined data service dynamically adjusts, further comprise: the transmission rate of at first adjusting the minimum data service of priority; During still more than or equal to described predetermined system load-threshold, adjust the transmission rate of the data service of next priority again, in the present load of statistics until the transmission rate of the highest data service of priority.

8. a kind of method that improves the CDMA mobile communication systems capacity according to claim 1 is characterized in that: also comprise in the transmission rate that reduces data service and reduce its transmitting power; With, when reverting to value before adjusting, the transmission rate with adjusted data service also comprises its transmitting power of increase.

9. a kind of method that improves the CDMA mobile communication systems capacity according to claim 8, it is characterized in that: the transmission rate of described reduction data service and transmitting power thereof, revert to the value before adjusting and increase its transmitting power with transmission rate adjusted data service, it is front end signal processing subsystem power controlling control subsystem by the user of mobile station end, with data-message distribution module, finish by load control module in the control resource management module and power controlling control subsystem by base station end and base station controller thereof.

10. a kind of method that improves the CDMA mobile communication systems capacity according to claim 9 is characterized in that further comprising:

A. measurement report is measured and generated to the user of mobile station end to the signal quality that receives, and this measurement report sends to the base station with the reverse feedback link signal;

B. base station controller is handled and sent in the base station to the reverse signal that receives;

C. estimate the information bit energy of this user of mobile station signal and the ratio of disturbance spectrum density by the baseband processing unit in the base station controller, and compare, determine power control ratio specially for 0 or 1, and send it to this user of mobile station with the threshold value of setting;

D. the information detection system load constantly that reports according to the base station of base station controller, and compare with the system load thresholding of setting, in the system load that detects during greater than this thresholding, press R '=2 * (1-Q) * R algorithm and adjust the transmission rate of current data business, R is the transmission rate of former data service, and Q is for working as preload percentage;

E. during less than the system load thresholding set, make the transmission rate R ' of current data business keep or revert to the transmission rate R of former data service in the system load that detects;

F. user of mobile station increases or the reduction transmitting power according to the power control bit that is received is corresponding.

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