KR100438174B1 - Method for data transmission ratio controlin synchronous mobile communication system - Google Patents

Abstract

The present invention provides a packet data service in a mobile communication system.

In the present invention, the base station calculates the number of slots (DRC Length) to use when transmitting data using the pilot information received from the mobile station; The mobile station using the pilot information received from the base station to calculate a desired data rate (DRC value); The mobile station using the DRC Length transmitted from the base station, transmitting the DRC value to the base station through a DRC channel and requesting a data transmission rate; A base station accumulating the DRC Value information received from the mobile station and calculating an average value; Determining whether the calculated average value corresponds to a satisfaction rate range for servicing data; and correcting the DRC value; and when retransmitting is requested from the mobile station due to an error when transmitting data with the corrected DRC value, the data is returned to the original DRC value. Retransmitting; It is characterized by including.

Description

Method for controlling data transmission rate in synchronous mobile communication system {Method for data transmission ratio control in synchronous mobile communication system}

The present invention relates to a packet data service in a mobile communication system, and more particularly, to a transmission rate control method for providing a packet data service to an subscriber at an improved transmission rate in a synchronous cdma 2000 1x EV-DO (HDR) system.

More specifically, the present invention provides data transmission / reception of a mobile communication system having a base station (hereinafter referred to as a mobile station) and a base station apparatus including a base station (AP) and a base station controller (APC). Calculate the number of slots (DRC Length) to use when transmitting data using the pilot information received from the mobile station, the mobile station calculates the desired data rate (DRC value) using the pilot information received from the base station, and transmits the By using the DRC Length, the DRC value is transmitted to the base station through the DRC channel and a data transmission rate is required.

Accordingly, the base station accumulates the DRC value information received from the mobile station and calculates an average value. The base station determines whether the calculated average value corresponds to a range of satisfaction speeds for serving data and corrects (modifies) the DRC value or is requested by the original AT. The present invention relates to a method for improving a packet data transmission rate corresponding to a wireless environment by performing a packet data service with a DRC value.

Hereinafter, the prior art will be described.

First, the general content of the related art will be described in relation to the present invention.

According to the theoretical result of the synchronous 1x EV-DO, the transmission area of the base station is reduced by up to 10% when transmitting at the maximum forward speed of 2.4576Mbps. These results indicate that the maximum transmission rate actually increases the energy level of the radio section due to the radio wave or interference of the base station in a commercial environment, thereby reducing the base station service area due to the increased error.

As the center of mobile communication system service is changed to packet data, the forward link budget has become more important in recent years as more downloads are made from the system.

1 is a block diagram of a conventional mobile communication system to which the present invention is applied.

As shown in the figure, a mobile station 11 (AT: Access Terminal), a base station 12a (AP: Access Point), a base station controller 12b (APC: Access Point Controller), and an exchange station 13 (MSC: Mobile) Switching Center).

Conventionally, in determining the forward transmission speed in the HDR high speed packet data transmission system, there are parameters such as a data rate control (DRC) value and a DRC Length that the terminal determines from its surrounding environment (wireless environment) conditions. The transmission rate depends on how efficiently the parameter values are determined according to the packet service requirements of the receiver.

AT (terminal) calculates DRC value by looking at pilot (C / I, Carrier to Interface) strength according to wireless environment from AP (base station).

The DRC value is a forward traffic channel transmission rate that the AT wants to receive from the AP, and is divided into 16 data transmission rates ranging from 38.4k to 2.4Mbps.

This is obtained through the process of the UE calculating its DRC value. The APC receives a Route Update message from the AT and calculates a DRC Length using the C / I information in the message and transmits the DRC Length to the AP and the AT.

The Route Update message is sent together with the message when a message is transmitted through a wireless environment change, other handoffs, or other access channels.

In addition, the DRC Length is the number of slots used when the AT transmits a single DRC value (transmission rate that the AT wants to be serviced) to the AP through the DRC channel, and the AP receives the DRC value transmitted in the DRC Lengthslot and is requested. The packet data is sent down to the forward traffic channel slot (when 38.4kbps, 16 slots are used for packet service). At this time, the AP bundles the forward traffic channel slot by the number of slots corresponding to the DRC value. Send data down to AT.

For example, if the DRC value = 38.4k, packet data is sent in 16 slots (spec defined in the forward) of the forward traffic channel. Currently, the default (default) DRC length is 1. In other words, when DRC length is 1, when packet data is sent to 16 slots, it is divided into 16 slots. If the value of DRC length is increased to 2, packet data can be sent every 2 slots when 16 slots are sent.

When transmitting packet data through a forward traffic channel, the AP transmits packet data to a serviceable AT at a DRC value (desired data rate). As the data service speed increases, the number of slots in the forward traffic channel allocated from the AP decreases according to the required speed.

That is, in the case of a high speed service, even if the number of slots allocated is small, a large amount of packet data service can be satisfied.

2 is a flowchart illustrating a procedure of serving conventional forward (base station-> mobile station) packet data.

As shown in FIG. 2, the AP transmits data at a transmission rate requested by the AT to the DRC value (desired data rate) required by the terminal AT.

However, in the case of the data service in the conventional mobile communication system, the poor service quality (speed, data quality) is degraded where the wireless environment is poor.

When the AT is in a poor wireless environment, the DRC value calculated by the AT is low, which means that the forward traffic channel transmission rate that the AT wants to receive from the AP is low.

Therefore, AT, which is in a poor wireless environment, will always repeat the vicious cycle of receiving only low-speed packet data transmission service. Of course, the AT may arbitrarily fix the DRC value, but if the wireless environment is poor, even if you want a high-speed service, the data will often be broken by the influence of the wireless environment, frequent retransmission requests, data reliability and retransmission The increase in load causes the efficiency of the system to decrease.

According to the present invention, when the AT calculates the DRC value, the calculated DRC value when the wireless environment is not good means that the forward traffic channel transmission rate that the AT wants to be serviced by the AP is low.

Accordingly, the present invention proposes a method of correcting a DRC value at a base station using a method of increasing a DRC Length value and / or a pilot strength.

1 is a block diagram of a conventional mobile communication system to which the present invention is applied.

2 is a flowchart illustrating a procedure of serving conventional forward (base station-> mobile station) packet data.

3 is a flowchart illustrating a procedure for serving forward (base station-> mobile station) packet data of the present invention.

The data transmission method in the synchronous mobile communication system of the present invention,

In the present invention, the base station calculates the number of slots (DRC Length) to use when transmitting data using the pilot information received from the mobile station; The mobile station using the pilot information received from the base station to calculate a desired data rate (DRC value); The mobile station using the DRC Length transmitted from the base station, transmitting the DRC value to the base station through a DRC channel and requesting a data transmission rate; A base station accumulating the DRC Value information received from the mobile station and calculating an average value; And determining whether the calculated average value corresponds to a range of satisfaction speeds to service data, and correcting the DRC value.

In addition, the present invention is characterized in that it further comprises the step of retransmitting the data in the original DRC value when the request for retransmission from the mobile station due to an error when transmitting data with the corrected DRC Value.

In another aspect, the present invention is characterized in that the base station checks the FER (Fream Error Rate) of the data received from the mobile station or counts the number of retransmissions.

In another aspect, the present invention is characterized by increasing the DRC Length value and / or pilot strength to improve the DRC value from the base station to the mobile station.

In addition, the present invention determines whether the average DRC value corresponds to the range of the satisfaction rate to service data, if the data service satisfaction rate range is within one step higher than the transmission rate corresponding to the DRC value originally requested by the AT packet data service If the data service satisfaction rate is not within the range, the packet data service is performed at the transmission rate corresponding to the DRC value originally requested by the AT.

Other objects and features of the present invention will become apparent from the detailed description of the embodiments with reference to the accompanying drawings.

Hereinafter, a method of improving data transmission speed according to the present invention will be described with reference to the accompanying drawings.

First, general matters related to the present invention will be described.

The 1x EV-DO of the present invention is a dedicated protocol for packet data transmission that is completely different from the conventional IS-2000 wireless protocol. When the maximum transmission rate is forward, a high-speed packet data transmission service can be performed using a method capable of up to 2.4567 Mbps. In this case, without changing the hardware system structure originally possessed by the synchronous mobile communication system, only a part of the transmission rate of packet data is modified on the call processing software routine of the AN (base station apparatus) (AP, APC). Alternatively, the present invention is to realize a transmission speed improvement at the AP (base station) which is the object of the present invention.

The 1x EV-DO, a synchronous mobile communication system, utilizes a method that makes full use of the "burst transmission" characteristic, which is inherent in packet data, and in this case, the base station side needs to operate the prioritization and scheduling very precisely. It is possible.

An implementation of the present invention is described below with reference to a flowchart illustrating a procedure for serving forward (base station-> mobile station) packet data in FIG. 3.

In general, a mobile communication system includes a protocol layer (layer) for processing data and control signals, and a DRC (Data Rate Control) that forms a subchannel in a reverse traffic channel structure among channel structures of a physical layer among the layers. There is a channel.

The DRC channel uses the reverse channel when the AT (terminal) requests the AN (base station apparatus) the desired transmission rate.

When the AT transmits a desired DRC value to the AN through the DRC channel, the AN receives this and initiates packet data transmission at a data rate that matches the DRC value among 12 data rate formats.

It will be described in detail with reference to FIG.

During forward packet data reception in the mobile communication system, AT receives a weak pilot with low C / I value from the AP due to deterioration of wireless environment, and AT receives AN when the wireless environment changes. The base station device sends a message to the APC via the access channle to update the AT's environmental information.

APC (Base International Controller) calculates the DRC Length using the strength (C / I) of the radio environment information pilot in the message and transmits it to the AT via the AP.

AT calculates DRC value using C / I, which is the pilot strength information, which is continuously received during packet data service, and transmits the DRC value to AP through DRC channel according to DRC Length transmitted from AP and transmits desired data. Demands speed.

In response, the AP performs a packet data service at a transmission rate corresponding to the DRC value requested by the AT.

On the other hand, the AP accumulates DRC value information received from the AT each time, and continues to calculate the average value for the accumulated value during the call progress.

More specifically, the process of deriving the average value will be described.

That is, if the AT has an environment with poor radio resources, the AT continues to receive a low pilot strength and continuously obtains a low value through the DRC value calculation.

The AT transmits the derived DRC value to the AP again, and the transmission rate is kept low.

The AP accumulates the DRC value to derive an average value of the DRC value through statistical processing to determine whether it is within the data service satisfaction rate range.

The data service satisfaction rate can be set by the service operator obtained in the process of 1x EV DO service to collect the information from the subscribers and set the service quality in the packet data service process. Here, the base station checks the FER of the data received from the mobile station, or counts the number of retransmissions.

If the derived DRC value average is within the satisfaction rate range of the data service, the AP sends down the DRC Length received from the APC to the AT, which is one step higher than the transmission rate corresponding to the DRC value originally requested by the AT. Perform

However, if the derived DRC value average value is not within the data service satisfaction rate range, the packet data service is performed at a transmission rate corresponding to the DRC value originally requested by the AT.

If the mobile station transmits data from the AP to the AT one step higher than the transmission rate requested or at the original transmission rate, and there is no error in the data received from the AT, it continues at the corrected rate until the next changed service rate is required. Maintain service.

However, when an error occurs by transmitting data from the AP to the AT at the first step or at the original transmission speed, the AT requests retransmission to the AP. At this time, the AP provides data service using the DRC value originally requested by the AT.

In FIG. 2 illustrating the conventional data rate procedure, the AP merely receives a message including a DRC Length value from the APC and transmits the message to the AT, whereas the AP in the present invention has a DRC Value received at the AT. By calculating the average value of the value, the original AT wants to provide a packet data service with a more improved rate through +/- 1 of the desired DRC value.

The meaning of +/- 1 means to correct the original DRC value, and is not necessarily a process to be performed.

As described above, the present invention relates to a transmission rate improvement for efficiently providing a forward packet data service transmitted from a base station to a mobile station, and the base station accumulates / averages the DRC value received from the terminal to satisfy the packet data service satisfaction rate range. If it is satisfied, it performs a procedure of correcting the DRC value when satisfied, and transmits it to the corrected DRC value, and when dissatisfied, provides packet data service with the DRC value originally requested by the AT.

However, when the received packet data has an error in the AT and the retransmission is requested, the AP performs retransmission with the DRC value originally requested by the AT.

Although the preferred embodiment of the present invention has been described above, the present invention may use various changes, modifications, and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the above embodiments.

Accordingly, the above description does not limit the scope of the invention as defined by the limitations of the following claims.

Therefore, the present invention solves the problem that the AT must continuously receive data at a low data rate when the conventional wireless environment is poor, and by accumulating / averaging the DRC Value received from the UE by managing the DRC Value at the base station, packet data It is possible to provide a packet data service at an improved transmission rate by determining whether it is in the service satisfaction rate range and correcting the DRC value.

Claims (5)

In a mobile communication system in which data transmission and reception between a mobile station and a base station apparatus are performed, Calculating, by the base station, the number of slots (DRC Length) to be used when transmitting data using pilot information received from the mobile station, and transmitting the calculated slot number to the mobile station; The mobile station calculates a data rate (DRC value) using the pilot strength information received from the base station, and transmits the DRC value (DRC value) to the base station through the DRC channel according to the DRC Length transmitted from the base station to the desired data Requesting a transmission rate; And accumulating the DRC value information received from the mobile station to calculate an average value, and determining whether the calculated DRC average value is within a satisfaction rate range of a data service, and correcting the DRC value. Data Rate Control Method in Synchronous Mobile Communication System . The method of claim 1, wherein the base station performs a packet data service at a rate one step higher than the transmission rate corresponding to the DRC value requested by the mobile station if the DRC average value is within the range of the satisfaction rate of the data service, And performing a packet data service at a transmission rate corresponding to the DRC value requested by the mobile station if the average DRC value does not belong to a rate range of a data service . The method of claim 1, wherein the base station corresponds to the original DRC value when an error occurs in specific data received from the mobile station and requests retransmission when performing a packet data service at a data rate corresponding to the corrected DRC value. Retransmitting the corresponding data at a transmission rate to the data transmission rate control method in a synchronous mobile communication system. The synchronous mobile communication system of claim 1, wherein the base station checks whether the base station checks the FER (Fream Error Rate) of data received from the mobile station or counts the number of retransmissions. Data rate control method. The method of claim 1, wherein a DRC Length value and / or a pilot strength is increased to improve the DRC value from the base station to the mobile station.