CN1404248A - Dynamic channel configuration method based on source rate estimation - Google Patents

Abstract

In the CDMA cellular mobile communication system, packet services are characterized by burstiness and a large dynamic range of rate changes. To improve the utilization efficiency of system resources, it is necessary to carry out dynamic and reasonable channel allocation. Any unreasonable channel resource allocation will lead to Decrease in system resource utilization and degradation in communication quality. Dynamic channel configuration is achieved by performing traffic measurements and reporting the measured traffic. This patent proposes a dynamic channel configuration method based on estimating the source rate of the service, which can accurately and quickly estimate the instantaneous rate of the service source, and thus configure new channel resources, effectively improving the utilization of system resources and reducing unnecessary The number of channel reconfigurations necessary.

Description

A Dynamic Channel Allocation Method Based on Source Rate Estimation

Technical field

The invention relates to a communication system, especially a method for dynamic channel reconfiguration based on source rate estimation in a CDMA cellular mobile communication system.

Background technique

With the development and rapid popularization of the Internet, more and more wireless devices (such as mobile phones) provide Internet access functions, and enjoy the packet services with very large data rates of business sources such as WWW browsing, FTP downloading, and E_Mail provided by the Internet. For example, when the user clicks on the WWW page connection, a download request will be sent. During this request, one or more packet sequences will be sent. At this time, there will be a large amount of data on the channel to request rapid transmission; After the document is downloaded, the user spends a certain amount of time reading it, so the amount of data on the channel becomes very small at this time. It can be seen from this that these packet services are characterized by burstiness and a large dynamic range of rate changes. If the channel resource of fixed bandwidth is allocated to this service according to the conventional method, the demand for fast data transmission may not be satisfied when the service bursts, and the redundant channel resource will be wasted when there is little service data. An effective solution is to dynamically configure the channel according to the changing characteristics of the business. If the current data rate to be transmitted is so high that the originally allocated channel bandwidth cannot meet the requirements, the channel will be reconfigured and assigned to it. Larger channel resources; when relatively idle, reconfigure a small bandwidth to the service again, thereby improving the utilization efficiency of channel resources.

Figure 1 shows a typical feature of a packet service. It can be seen from Fig. 1 that the conversation process of a packet service is composed of several packet calls, and each packet call contains multiple packet requests, and there is a certain arrival time interval between packets, when a packet call arrives , the user spends a period of time (reading time) to read the arriving data, and there is very little data on the channel during this period of time; when the data reading is completed, the group call is initiated again; this loops continuously until the end of the service.

To improve resource utilization efficiency, it is necessary to dynamically configure appropriate channel resources for certain packet services, thereby reserving more resources for the system to provide more user access services. This means that for a certain variable-rate service, we need to track its changing data requirements in time to provide a reliable basis for dynamic channel configuration.

In the third generation mobile communication system, dynamic channel configuration is realized through traffic measurement. During the communication of the data service, the service volume of the service is continuously measured, and the parameters related to the measurement are configured by the upper layer, including the measurement object, the quantity to be measured, the trigger threshold and the reporting method, etc. When the reporting method is aperiodic, if the measured traffic reaches or exceeds the trigger threshold, a traffic measurement report will be initiated; when the reporting method is periodic, the measured traffic will be reported to the The upper layers are used to make decisions on dynamic channel configuration.

FIG. 2 shows a schematic diagram of an event-triggered traffic report. The service volume in Fig. 2 may be the data volume to be transmitted in the buffer zone, and the trigger threshold is given by the high layer through measurement control. In Figure 2a, when the measured traffic volume exceeds the upper threshold, a traffic report that exceeds the upper threshold is triggered; similarly, in Figure 2b, when the measured traffic volume is lower than the lower threshold, a report that is lower than the lower threshold is triggered. Traffic report. The report will give the measured data volume of the buffer corresponding to the service, or also include the mean value and variance of the data volume.

After receiving the service volume report, the upper layer performs dynamic channel configuration according to the measurement results in the report: if the measured service volume exceeds the upper threshold, configure a channel with a larger capacity than the current channel for the service (or user), In order to better meet the user's service needs; on the contrary, if the measured traffic is lower than the lower threshold, the service (or user) is configured with a channel with a smaller capacity than the currently used channel, and more channels are reserved for the system. Wireless resources, thereby improving the resource utilization efficiency of the system.

But the problem lies in how to configure a more appropriate channel capacity for the service more accurately after receiving a traffic report. If the reconfigured capacity is larger than the actual required capacity after receiving the measurement report that the traffic volume exceeds the upper threshold, a traffic volume report that needs to reduce the channel capacity may follow; on the contrary, if the reconfigured channel capacity is still If the capacity is not enough for actual needs, there will be a follow-up traffic report to continue to increase the channel capacity. Similarly, after receiving a traffic report that the traffic volume is lower than the lower threshold, if the reconfigured capacity is inconsistent with the actual required capacity, an additional traffic report for reconfiguring the channel capacity will be caused. On the one hand, this cannot well meet the service requirements of users, and on the other hand, it also brings more and unnecessary signaling processes such as traffic reporting and channel reconfiguration, which reduces the overall performance of the system.

Contents of the invention

The purpose of the present invention is to provide an accurate channel capacity reconfiguration strategy through a method for estimating the data source rate of services, thereby improving the utilization efficiency of system channel resources while meeting user service quality (Qos) requirements, and avoiding Many unnecessary channel reconfiguration processes reduce signaling interaction and improve system performance.

The present invention is achieved in this way, a method for dynamic channel reconfiguration based on data source rate estimation in a CDMA cellular mobile communication system, said method comprising the following steps:

a. After establishing a user's packet service, the channel configuration module in the system allocates initial channel resources for the packet service;

b. The dynamic channel configuration module in the system configures appropriate measurement control parameters according to the initially allocated channel resources, and the measurement control parameters include measurement objects, measurement quantities, upper and lower thresholds Th or measurement periods for triggering measurement reports, and hysteresis time Ttring and reporting method;

c. During the data transmission of the packet service, continuously measure the traffic of the packet service according to the configured measurement control parameters, and initiate a traffic measurement report to the dynamic channel configuration module in the reporting manner;

d. The dynamic channel configuration module receives the traffic measurement report, detects the traffic measurement value Sm and the measurement control parameter from the traffic measurement report, estimates with the following formula, and obtains the data source rate of the current moment business,

R(n+1)＝[(Sm-Th)/Ttring]+R(n) (1)

Sm is the traffic measurement value in the traffic report, Th is the threshold value for triggering the traffic report, R(n) is the channel bandwidth configured for the service before the dynamic channel configuration module of the system receives the traffic measurement report, Ttring is the lag time;

e. The dynamic channel configuration module compares the data source rate of the packet service at the current moment obtained in step d with the configured data rate, and if the ratio between the two is greater than parameter A1 or less than parameter A2, then it is determined that the user needs to configure a new channel If the ratio of the two is not greater than the parameter A1 or not less than the parameter A2, it is determined that the user does not need to configure a new channel bandwidth and returns to step c.

The range of the parameter A1 may be between 1-10, and the range of the parameter A2 may be between 0.1-1.

By adopting the dynamic channel configuration method of the present invention, the resource utilization efficiency of the system can be fully improved under the premise of satisfying the user service QoS. Compared with the general dynamic channel configuration method, this algorithm has the following advantages,

1) Due to the accurate rate estimation of service data sources during dynamic channel configuration, it provides a powerful reference for configuring appropriate channel bandwidth;

2) Combined with the reconfiguration process of rate estimation, it can more dynamically meet the needs of user data transmission, and also improve the utilization efficiency of channel resources in the system;

3) The dynamic channel configuration combined with the rate estimation avoids many unnecessary reconfiguration processes, reduces the signaling process of the system, and improves the overall performance of the system.

Description of drawings

Figure 1: Schematic diagram of the business model of the WWW browsing service

Figure 2a: Schematic diagram of traffic report triggered by traffic exceeding the upper threshold

Figure 2b: Schematic diagram of the traffic report triggered by the traffic volume below the lower threshold

Figure 3a: Schematic Diagram 1 of Service Data Source Rate Estimation Method

Figure 3b: Schematic diagram of the estimation method of service data source rate II

Figure 4: Schematic diagram of the algorithm flow

Figure 5: Schematic diagram of the traffic volume report of the embodiment

Detailed ways

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

As shown in Figure 5, firstly a user's packet service is established, and the channel configuration module in the system allocates initial channel resources for the packet service. The dynamic channel configuration module in the system configures appropriate measurement control parameters according to the initially allocated channel resources. The measurement control parameters include measurement objects, measurement quantities, upper and lower thresholds Th or measurement periods for triggering measurement reports, lag time Ttring, and reporting methods. During the data transmission of the packet service, the traffic volume of the packet service is continuously measured according to the configured measurement control parameters, and a traffic volume measurement report is sent to the dynamic channel configuration module in a periodic or aperiodic reporting manner. The service volume is the data volume to be transmitted in the buffer corresponding to the packet service, and also includes the mean and variance of the data volume.

The dynamic channel configuration module receives the traffic measurement report, detects the traffic measurement value Sm and the measurement control parameter from the traffic measurement report, estimates with the following formula, and obtains the data source rate of the current moment business,

R(n+1)＝[(Sm-Th)/Ttring]+R(n) (1)

Sm is the traffic measurement value in the traffic report, Th is the threshold value for triggering the traffic report, R(n) is the channel bandwidth configured for the service before the dynamic channel configuration module of the system receives the traffic measurement report, Ttring is the delay time; the dynamic channel configuration module compares the data source rate of the packet service at the current moment with the configured data rate, and if the ratio between the two is greater than parameter A1 or less than parameter A2, it is determined that the user needs to configure a new channel bandwidth ; If the ratio of the two is not greater than the parameter A1 or not less than the parameter A2, it is determined that the user does not need to configure a new channel bandwidth. The range of parameter A1 may be between 1-10, and the range of parameter A2 may be between 0.1-1.

Assuming that at the moment of communication T0, the channel bandwidth configured by the channel configuration module in the system for the packet service is 32kpbs; let A1 be 1.5, and A2 be 0.5, and the dynamic channel configuration module in the system configures the measurement control according to the initially configured channel bandwidth The parameters are as follows:

The upper threshold THu for triggering the traffic measurement report: 200k bits; the lower threshold TH1 for triggering the traffic measurement report: 20k bits; the delay time Ttrig for triggering the traffic measurement report: 1s; the reporting method is aperiodic;

During the data transmission of the packet service, the traffic volume of the packet service is continuously measured according to the configured measurement control parameters, and a traffic measurement report is sent to the dynamic channel configuration module in an aperiodic report mode, and the dynamic channel configuration module receives A traffic measurement report, detecting the traffic measurement value Sm' from the traffic measurement report.

R1, R2, and R3 represent three traffic measurement reports respectively, and the corresponding times are T1, T2, and T3 respectively. The traffic measurement values carried in the traffic measurement reports are respectively Sm1=205k, Sm2=253k, and Sm3=0.2k . It is also assumed that the measurement reports R1 and R2 are triggered because the service volume exceeds the upper threshold for triggering the service volume measurement report, and the measurement report R3 is triggered because the service volume is lower than the lower threshold for triggering the service volume measurement report.

When the dynamic channel configuration module in the system receives the traffic measurement report R1, according to the traffic data source rate estimation method, the formula

R(n+1)=[(Sm-Th)/Ttring]+R(n) (1) The data source rate of the packet service at the current time corresponding to time T1 can be obtained: 32+(205-200)/1 =37kbps, the dynamic channel configuration module compares the data source rate of the packet service at the current moment with the configured channel data rate, and its ratio is 1.16. New measurement control parameters need to be configured. This can appropriately reduce the signaling process, but has little impact on user communication.

When the dynamic channel configuration module in the system receives the traffic measurement report R2, according to the business data source rate estimation method, it can be obtained that the instantaneous data rate of the packet service at the current moment corresponding to the time T1 is: 32+(253-200)/ 1=85kbps, so it can be obtained that the channel bandwidth required by the current user is 85kbps. The dynamic channel configuration module compares the data source rate of the packet service at the current moment with the configured channel data rate. The ratio is 2.7, which is already greater than parameter A1. It is determined that the data source rate of the packet service at the current moment is much higher than the configured channel. data rate, the service data source rate estimate is the channel bandwidth required by the user, and the dynamic channel configuration module re-allocates a wider channel bandwidth for the packet service initiated by the user according to the comparison result, and configures it according to the channel bandwidth required by the user New measurement control parameters.

When the dynamic channel configuration module in the system receives the traffic measurement report R3, according to the business data source rate estimation method, it can be obtained that the instantaneous data rate of the packet service at the current moment corresponding to the time T1 is: 32+(0.2-20)/ 1=12.2kbps, so it can be obtained that the channel bandwidth required by the current user is 12.2kbps. The dynamic channel configuration module compares the data source rate of the packet service at the current moment with the configured channel data rate, and the ratio is 0.4, which is smaller than parameter A2, so it is determined that the data source rate of the packet service at the current moment is much lower than the configured channel data rate, the service data source rate estimate is the channel bandwidth required by the user, and the dynamic channel configuration module re-allocates a narrower channel bandwidth for the packet service initiated by the user according to the comparison result, and configures it according to the channel bandwidth required by the user The new measurement and control parameters achieve the purpose of improving the resource utilization efficiency of the system.

In the above embodiments, the parameters A1 and A2 and the measurement control parameters can be adjusted as required, and the reporting method can also be periodic.

Claims (2)

1, a kind of dynamic channel allocation method based on data source rate estimation in the CDMA cellular mobile communication system, it is characterized in that, described method comprises the following steps: a. After establishing a user's packet service, the channel configuration module in the system allocates initial channel resources for the packet service; b. The dynamic channel configuration module in the system configures appropriate measurement control parameters according to the initially allocated channel resources, and the measurement control parameters include measurement objects, measurement quantities, upper and lower thresholds Th or measurement periods for triggering measurement reports, and hysteresis time Ttring and reporting method; c. During the data transmission of the packet service, continuously measure the traffic of the packet service according to the configured measurement control parameters, and initiate a traffic measurement report to the dynamic channel configuration module in the reporting manner; d. The dynamic channel configuration module receives the traffic measurement report, detects the traffic measurement value Sm and the measurement control parameter from the traffic measurement report, estimates with the following formula, and obtains the data source rate of the current moment business, R(n+1)＝[(Sm-Th)/Ttring]+R(n) (1) Sm is the traffic measurement value in the traffic report, Th is the threshold value for triggering the traffic report, R(n) is the channel bandwidth configured for the service before the dynamic channel configuration module of the system receives the traffic measurement report, Ttring is the lag time; e. The dynamic channel configuration module compares the data source rate of the packet service at the current moment obtained in step d with the configured data rate, and if the ratio between the two is greater than parameter A1 or less than parameter A2, then it is determined that the user needs to configure a new channel If the ratio of the two is not greater than the parameter A1 or not less than the parameter A2, it is determined that the user does not need to configure a new channel bandwidth and returns to step c. 2. The method according to claim 1, further characterized in that the range of the parameter A1 can be between 1-10, and the range of the parameter A2 can be between 0.1-1.

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