RU2348116C2 - Device and method for control of data transmission speed in reverse communication line - Google Patents

Abstract

FIELD: physics, communication.

SUBSTANCE: invention is related to systems of wireless communication. Device and method for control of data transmission speed in system of wireless communication in service transmission comprises terminal that identifies active set containing service base station and at least one non-servicing base station compared to terminal that exchanges data with network at the first speed of data transmission, which receives the first parameter of speed control from service base station and the second parameter of speed control from at least one non-servicing base station, at that the first and second parameters of speed control are associatively connected with determination of the second speed of terminal data control in process of service transmission, and determining the second speed of data transmission in response to the first and second parameters of speed control, at that the second speed of data transmission one of increased speed, reduced speed and the same speed compared to the first speed of data transmission.

EFFECT: efficient transmission of data by terminal by account of resources condition and condition of terminal channel.

14 cl, 8 dwg

Description

Cross reference to related applications

This application claims the benefit of Applications (Korea) of numbers 10-2003-0014036, 10-2003-0027199 and 10-2003-0076562, filed March 6, 2003, April 29, 2003 and October 31, 2003, respectively, the contents of which are fully contained in this reference document for all purposes.

This application also claims the benefit of Provisional Applications (USA) serial numbers 60/514383, 60/515897 and 60/516232, filed October 24, 2003, October 29, 2003 and October 30, 2003, respectively, the contents of which are fully contained in this document in as a reference for all purposes.

State of the art

FIELD OF THE INVENTION

The present invention relates to wireless communication systems, and more particularly, to a method for controlling a data rate for a reverse link, in which the state of a mobile station or terminal is used to determine whether a target data rate can be supported, and, in turn, how to obey the command of the base station.

Description of the Related Art

In the world of cellular communications, those skilled in the art often use the terms 1G, 2G, and 3G. These terms mean the generation of cellular technology used. 1G stands for first generation, 2G stands for second generation, and 3G stands for third generation.

1G is used to refer to an analog telephone system known as the AMPS (Advanced Mobile Phone Service) telephone system. 2G is typically used to refer to digital cellular systems that prevail around the world and include CDMAOne, Global System for Mobile Communications (GSM), and Time Division Multiple Access (TDMA). 2G systems can support more users in a dense area than 1G systems.

3G is typically used to refer to digital cellular systems currently under development. Recently, third generation (3G) CDMA communication systems have been proposed, including such offers as cdma2000 and W-CDMA. These 3G communication systems are conceptually similar to each other with several significant differences.

The cdma2000 system is a third-generation (3G) broadband radio interface system that leverages the advanced service potential of CDMA technology to facilitate support for data transfer modes such as access to the Internet and intranets, multimedia applications, high-speed business operations and telemetry. The focus of cdma2000, like other third-generation systems, is to use the network economically and the structure of the radio transmission to overcome the limitations of the final available radio frequency spectrum.

Figure 1 illustrates the architecture of a wireless communication network.

Referring to FIG. 1, a subscriber uses a mobile station to access network services. The mobile station may be a portable communication device, such as a portable cell phone, a communication device installed in a vehicle, or even a fixed communication device.

Electromagnetic waves from a mobile station are transmitted through a Base Transceiver System (BTS), also called Node B. A BTS consists of radio devices such as antennas and radio transmission equipment. A base station controller (BSC) receives transmitted data from one or more BTS. The BSC provides monitoring and control of the broadcast from each BTS through messaging with the BTS and the Mobile Switching Center (MSC) or internal IP network. BTS and BSC are part of a base station (BS).

The BS exchanges messages and transmits data to a circuit switched core network (CSCN) and a packet switched core network (PSCN). CSCN provides traditional voice communications, and PSCN provides Internet applications and multimedia services.

The CSCN Mobile Switching Center (MSC) provides switching for traditional voice communications to and from a mobile station and can store information to support these capabilities. The MSC can be connected to one or more BSs, as well as to other open networks, such as a public switched telephone network (PSTN) or a digital network with integrated services (ISDN). The visitor location register (VLR) is used to retrieve information for processing voice communications from and from the visitor subscriber. The VLR may be within the MSC and may serve multiple MSCs.

User credentials are assigned to the CSCN Own Subscriber Registry (HLR) for recording purposes, such as subscriber information such as electronic serial number (ESN), mobile subscriber number (MDR), profile information, current location, and authentication period. The Authentication Center (AC) manages the authentication information associated with the mobile station. AC can be in the framework of the HLR and can serve multiple HLR. The interface between SC and HLR / AC is an IS-41 interface.

Part of a Packet Data Service Node (PDSN) The PSCN provides routing packet data traffic to and from the mobile station. A PDSN establishes, maintains, and terminates link layer sessions in a mobile station and can communicate with one or more BSs and one or more PSCNs.

The Authentication, Authorization, and Accounting (AAA) server provides authentication, authorization, and accounting over IP protocol functions related to packet data traffic. The Home Agent (HA) provides authentication of the MS IP registrations, forwards packet data to and from the foreign agent (FA) component of the PDSN, and receives user initialization information from the AAA. HA can also establish, maintain, and terminate secure communications with the PDSN and assign a dynamic IP address. The PDSN communicates with AAA, HA, and the Internet through an internal IP network.

2 illustrates a link layer protocol architecture for a wireless network.

Referring to FIG. 2, the upper layer comprises three main services: voice services 62, data services 61, and signal transmissions 70. Voice services 62 include access to PSTN, voice services between mobile stations and Internet telephony. Data exchange services 61 are services that deliver any form of data on behalf of the end user of the mobile station and include packet data applications (for example, an IP service), channel data applications (for example, asynchronous fax and B-ISDN emulation services ) and SMS. Signal transmission 70 controls all aspects of mobile communications.

The link layer 30 is divided into a link access control (LAC) sublayer 32 and a medium access control (MAC) sublayer 31. The link layer provides protocol support and control mechanisms for data services and performs the functions necessary to correlate the data transfer needs of the upper layers 60 with the specific capabilities and characteristics of the physical layer 20. The channel layer 30 can be considered an interface between the upper layers and the physical layer 20.

The separation of MAC 31 and LAC 32 sublevels is due to the need to support a wider range of higher-level services and the requirement to provide data services with high efficiency and low latency over a wide speed range (from 1.2 Kbps to more than 2 Mbps). Other motivating factors are the need to support the provision of high QoS in packet and channel data services, such as restrictions on available delays and / or bit error rate (BER) of data, as well as the growing demand for the latest multimedia services, each of which has different QoS requirements.

A LAC sublayer 32 is necessary to provide a reliable serial control function for the point-to-point radio link 42. The LAC sublayer manages point-to-point communication channels between higher-level entities and provides a framework to support a wide range of various reliable end-to-end link layer protocols.

MAC Sublayer 31 facilitates the comprehensive multimedia, multifunctional capabilities of 3G wireless networks with QoS capabilities for each active service. MAC sublayer 31 provides procedures for controlling access of data services (packet and channel) to the physical layer 20, including managing conflicts between several services from a single user, as well as between competing users in a wireless system. The MAC sublayer 31 also provides sufficient reliable transmission over the radio link layer using the Radio Link Protocol (RLP) 33 for the highest possible level of reliability. Packet Radio Signaling Protocol (SRBP) 35 is an entity that provides a connectionless signaling protocol. Multiplexing and Quality of Service (QoS) management 34 is responsible for activating agreed QoS levels by placing conflicting requests from competing services at an intermediate level and appropriately prioritizing access requests.

The physical layer 20 is responsible for encoding and modulating data transmitted over the air interface. The physical layer 20 maintains a certain state of digital data from higher layers so that data can be reliably transmitted over a mobile radio channel.

The physical layer 20 displays user data and signaling data that is delivered via the MAC sublayer 31 over several transport channels to the physical channels and transmits the information over the air interface. In the transmission direction, the functions performed by the physical layer 20 include coding, interleaving, scrambling, spreading coding and channel modulation. In the receiving direction, functions are reserved to recover the transmitted data at the receiver.

The optimal data rate in the reverse link of a mobile communication system, for example, the first developed data-optimized system (1xEV-DO) is determined relative to the increase in thermal noise of a given base station. An increase in thermal noise is a dynamic reception characteristic defined as the total power of the total power signals received at the base station from all active mobile stations (also referred to as terminals) and thermal noise recognized at the base station. In other words, thermal noise increase is the summed signal power of active terminals received by the base station, which is a function of the inverse activity, i.e. the number and transmission rate of active terminals working in conjunction with the base station.

Ideal reverse link conditions arise when the terminal noise increase in the base station is kept constant despite fluctuations in reverse activity, so that the thermal noise increase is a function of different data rates for a given number of active terminals. Thus, the system performs the adjustment by controlling, among other things, the data rate on the reverse link of each terminal. To carry out this control, the increase in thermal noise is compared with a threshold level and, based on the comparison results, an active terminal is requested to increase or decrease its transmission rate when exchanging data with the base station. Those. the data transfer rate can be increased when the increase in thermal noise is less than a threshold, however, if the increase in thermal noise exceeds a threshold, it is necessary to reduce the data transfer rate.

1 illustrates a method for controlling a data rate in a reverse link according to the prior art. In FIG. 1, one base station and one active terminal of a 1xEV-DO system interact in each frame to set an optimal rate for each subsequent reverse link frame.

In step S100, the base station measures a thermal noise increase (RoT) generated by the total power action of all reverse link data signals. Using the thermal noise enhancement thus determined, the base station generates a reverse activity bit (RAB) in step S110 as part of the control word for use by the terminal. As described above, a value or RAB parameter is set according to a comparison of the thermal noise increase and a predetermined threshold value, with one value instructing the terminal to decrease its data rate, and another value should instruct the terminal to increase its data rate. In step S120, the base station transmits the reverse activity bit to all active terminals in active sectors, i.e. terminals transmitting data on the reverse link through a random access channel, which is a combined channel. Thus, all terminals simultaneously receive a control word containing one bit of feedback activity for a given frame, so that all terminals are simultaneously instructed to increase or decrease their set data rate for the next frame.

In step S130, the terminal receiving the reverse activity bit performs a conformance test to see if the data rate should be changed based on the received bit. For this, the terminal considers the transmission rate of the current frame on the reverse link and, using a predetermined algorithm, determines whether to act in accordance with the command from the base station and change the data transfer rate accordingly or ignore the command and set the transmission speed of the next frame equal to the speed of the current frame. Upon completion of the test and taking into account the reverse activity bit, the terminal sets the next frame rate in step S140.

In the above method, according to the prior art, a reverse activity bit is generated solely on the basis of an increase in thermal noise measured at the base station, and thus the generated bit is simultaneously transmitted as one command to all active terminals in active sectors. In other words, the status of none of these terminals is taken into account. As a result, this method has inherent disadvantages. For example, from the point of view of the terminal, in addition to acting in accordance with the command from the base station, the only option for the terminal is to ignore the command and keep the current data rate. Therefore, since the terminal cannot operate in view of its state, the data transmission efficiency in the reverse link is reduced. On the other hand, from the point of view of the base station, the terminal receiving the reverse activity bit may or may not act according to the corresponding command based on the results of its own compliance test and therefore may ignore the command to change its data rate. Therefore, it is difficult to effectively control the increase in thermal noise, which also reduces the efficiency of using the reverse link.

SUMMARY OF THE INVENTION

Therefore, the present invention is directed to a method that substantially eliminates one or more problems caused by the limitations and disadvantages of the prior art.

The purpose of the present invention, which is designed to solve the above problem, is to provide a reverse link data rate control method that allows a mobile station (terminal) to efficiently transmit data by accounting for resource status and channel status of the terminal.

Another objective of the present invention is to provide a method for controlling the data rate of the reverse link, which improves the efficiency of data transmission on the reverse link in a mobile communication system.

Another objective of the present invention is to provide a method for controlling the data rate in the reverse link, which reduces the increase in thermal noise experienced in the base station of a mobile communication system.

Additional features and advantages of the invention are set forth in the following description and, in part, should become apparent to those skilled in the art after reviewing it, or may be learned from the practice of the invention. The objectives and other advantages of the invention are realized and achieved by the essence, in particular, disclosed in the specification and claims, as well as in the accompanying drawings.

In order to achieve these goals and other advantages in accordance with the present invention, implemented and described in detail herein, a method for controlling a data rate in a wireless communication system for exchanging data between a network and a terminal is provided, the method comprising the steps of taking an information parameter from a terminal communicating with the network at a first data rate, wherein the information parameter is associated with at least the amount of data transmitted to the network; determining a speed control parameter in response to the information parameter, the speed control parameter being associated with controlling the first terminal data rate and comprising at least one of the first, second and third control states; and transmitting the rate control parameter to the terminal that provided the network with an information parameter to determine a second data rate in response to the rate control parameter, the second data rate being one of an increased, decreased, or the same as the first data rate. Preferably, the second data rate is controlled by a predetermined step in response to the rate control parameter.

According to one aspect of the invention, the information parameter is associated with the allowable power transmitted by the terminal and is transmitted via a packet data feedback control channel, and is associated with at least one power and data required to support an increased data rate.

According to another aspect of the invention, if a first control state is assigned to the rate control parameter, the terminal determines the second data rate as one of the increased speed, if the terminal can support the increased speed, the same speed and reduced speed compared to the first data rate. If a second control state is assigned to the rate control parameter, the terminal determines the second data rate as a reduced speed compared to the first data rate. If a third control state is assigned to the speed control parameter, the terminal determines the second data rate as one of the increased speed, if the terminal can support the increased speed, and the same speed compared to the first data rate. The speed control parameter can be set by the network periodically or aperiodically.

According to another aspect of the invention, the speed control parameter comprises one symbol, wherein the symbol comprises at least three states. Preferably, the speed control parameter is transmitted when it is associated with one of the first or second control state, and is not transmitted when it is associated with a third control state.

According to one embodiment, a method for controlling a data rate in a terminal comprises the steps of the terminal providing an information parameter and exchanging data with the network at a first data rate, the information parameter being associated with at least the amount of data that is transmitted to the network; receiving a speed control parameter from the network in response to an information parameter, wherein the speed control parameter is associated with controlling the data rate of the terminal and contains at least one of the first, second and third control states; and in response to the rate control parameter, the terminal determines a second data rate, the second data rate being one of an increased speed, a reduced speed, and the same speed compared to the first data rate.

According to another aspect of the invention, a wireless terminal used in a wireless communication system comprising a network comprises an antenna; a processor for controlling a mobile station; a display communicating with the processor to display user interface information; and a keyboard communicating with the processor to input user-driven data, the processor comprising means for providing an information parameter and exchanging data with the network at a first data rate, the information parameter being associated with at least the amount of data that is transmitted to the network ; means for receiving a speed control parameter from the network in response to an information parameter, the speed control parameter being associated with controlling the data rate of the terminal and comprising at least one of the first, second and third control states; and means for determining a second data rate in response to the rate control parameter, the second data rate being one of an increased speed, a reduced speed, and the same speed compared to the first data rate.

In another embodiment of the present invention, transmission rate control in a handover is described. The method comprises the steps of recognizing an active set comprising a serving base station and at least one non-serving base station with respect to a terminal communicating with the network at a first data rate; receiving a first speed control parameter from a serving base station and a second speed control parameter from at least one non-serving base station, the first and second speed control parameters being associated with determining a second terminal data rate during a handover; and determining a second data rate in response to the first and second speed control parameters, the second data rate being one of an increased speed, a reduced speed, and the same speed compared to the first data rate. Preferably, the first rate control parameter comprises a first state associated with an increase in a first data rate, a second state associated with a decrease in a first data rate, and a third state associatively associated with maintaining a first data rate, and a second rate control parameter comprises a fourth state associated with a decrease in the first data rate.

According to another aspect of the invention, a wireless terminal used in a wireless communication system comprising a network comprises an antenna; a processor for controlling a mobile station; a display communicating with the processor to display user interface information; and a keyboard communicating with the processor to input user-driven data, wherein the processor comprises active set recognition means comprising a serving base station and at least one non-serving base station with respect to a terminal communicating with the network at a first transmission rate data; means for receiving a first speed control parameter from a serving base station and a second speed control parameter from at least one non-serving base station, wherein the first and second speed control parameters are associated with determining a second terminal data rate during a handover; and means for determining a second data rate in response to the first and second speed control parameters, the second data rate being one of an increased speed, a reduced speed, and the same speed compared to the first data rate.

It should be understood that the foregoing explanation and the following detailed description of the present invention are exemplary and illustrative and are intended to provide an additional explanation of the invention according to the claims.

Brief Description of the Drawings

The accompanying drawings, which are included to provide an additional understanding of the invention and are registered and form part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the principle of the invention. In the drawings:

Figure 1 illustrates the architecture of a wireless communication network.

2 illustrates a link layer protocol architecture for a wireless network.

3 is a flowchart of a method for controlling a data rate of a reverse link in accordance with the prior art.

4 is a flowchart of a method for controlling a reverse link data rate according to a preferred embodiment of the present invention.

5 is a flowchart of a method for setting a data rate in a terminal according to a preferred embodiment of the present invention.

6 illustrates a handover mode data transmission scheme according to a preferred embodiment of the present invention.

7 is a diagram of a channel structure for transmitting a plurality of speed control bits and a corresponding plurality of ACK / NACK bits in order to implement a preferred embodiment of the present invention.

FIG. 8 illustrates a block diagram of a mobile station according to a preferred embodiment of the present invention.

Detailed Description of Preferred Options

the implementation

The following is a detailed description of a preferred embodiment of the present invention, examples of which are illustrated in the accompanying drawings. Wherever, the same reference numbers are used in the drawings to refer to the same or similar elements. To help describe the present invention, certain parameter names are used to describe the channels, messages, and variables transmitted between mobile and base stations. It should be noted that these parameter names are for illustrative purposes only, and other names may be used to describe the same or similar function.

3 illustrates a flow diagram of a method for controlling a reverse link data rate according to a preferred embodiment of the present invention. 3, at least one base station is communicating with one of a plurality of mobile stations or terminals. When transmitting data on the reverse link, however, it is the terminal, and not the base station, that typically initiates a transmission that is independent of any base station. Thus, when determining the initial transmission rate, the terminal, which is provided with data that must be transmitted to the base station on the reverse link, performs one or two processes. In one of them, data is initially transmitted at the lowest data rate that is currently supported by the terminal, for example, 9.6 Kbit / s, which is the speed set without interaction from the base station. In another, data is transmitted from the terminal at a rate determined by negotiation between the terminal and the base station, for example, 38.4 Kbps. The agreed transmission rate is set by the terminal after negotiating with the base station the optimal transmission rate.

As shown in step S200 of FIG. 4, at the beginning of the reverse link data transmission at a predetermined speed determined in accordance with the description above, the terminal according to the preferred embodiment transmits an information parameter, preferably at least one bit, for example, a bit information about the state of the mobile station informing the base station about the status of the transmitting terminal. Preferably, the state of the terminal may be based on the amount of transmit power of the reverse link, the status of the buffer, the amount of data to be transmitted, and other parameters that affect the desired transmission speed. However, for subsequent data transmission, the reverse link transmission rate may be adjustable, or at least the base station may influence it.

According to a preferred embodiment, the base station generates (S210) and gives each terminal (S220) a speed control parameter, preferably at least one reverse link data rate control symbol, in the form of a speed control bit (RCB), allocated to each terminal with a cell. The RCB preferably contains a symbol, each symbol representing three states, for example, +1, 0, or -1. When generating a dedicated RCB for each of the many terminals, the base station takes into account many factors, including the state of the reverse link channels, bits of information about the state of the terminal, the state of resources and the form of its services, the increase in thermal noise, etc.

It should be noted that the RCB information may contain several characters for use by the corresponding terminal, but one character may be used to indicate two or any of the three states. In the case of an RCB with two states, for example, one bit of RCB information, one logical state may indicate a command to increase the data rate of the terminal, while another logical state indicates a command to reduce its data rate. In this case, the third state may be indicated by the absence of RCB information from the base station, which means a hold command in order to maintain the data rate. Therefore, the RCB information contains command information to increase, decrease, or maintain the data rate of a predetermined terminal and thereby set the data rate of the reverse link. Moreover, the negotiation process between the base station and the terminal can be performed to specify the size or number of increases / decreases that must be performed for any transmitted command.

When generating the above RCB information for transmission to the terminal, the base station considers parameters such as thermal noise increase, terminal reverse link channel state and terminal status information bit, and determines whether its current data rate should be increased, decreased or maintained. The RCB information is then transmitted to the terminal, preferably periodically or aperiodically, by assigning a minimum transmission time unit, for example, of 20 ms, during each of which the base station performs at most one RCB information transmission.

The terminal receives the RCB (S230) and sets the data rate for each frame accordingly (S240) to control the reverse link speed. The control operation is shown in detail in Fig.5.

FIG. 5 illustrates a flowchart of an operation of a data rate control method according to a preferred embodiment of the present invention, in which the state of the terminal using the method is based on the state of the buffer, the amount of power available to the terminal, and the like. The status of the terminal is used to determine whether a target increase or decrease in the data rate can be supported, and, in turn, whether a command indicated by the RCB should be executed. In Fig. 5, the optimal data rate of frame i is determined by the corresponding terminal based on the received RCB indicating a command with one of increasing the transmission speed of the next frame by the agreed value α, decreasing the transmission speed of the next frame by the agreed value β and maintaining the current speed for the next frame.

Preferably, increasing and decreasing the transmission rate by the value of α and the value of β can be realized by increasing or decreasing the speed by predetermined steps. For example, if the increased speed is supported, then the terminal may increase the current transmission rate to a speed that is one level higher from the plurality of transmission speeds supported by the terminal. Similarly, if a reduced speed is supported, then the terminal can reduce the current transmission speed to a speed that is one level lower from the many transmission speeds supported by the terminal.

After receiving the dedicated RCB for a given frame by the appropriate terminal (S300), the terminal checks the value of the received RCB (S310) and determines the target command of the base station. If the value of the received RCB indicates a decrease command, the data rate decreases by a decrease value β relative to the speed of the previous frame (S320).

If the value of the received RCB indicates an increase command, the terminal checks its status to determine if the increased data rate can be supported (S330). If so, the data rate is increased by an increase value α relative to the speed of the previous frame (S340); otherwise, an additional determination is made to verify whether the terminal can support the current speed used in the current frame. That is, if the state of the terminal cannot support an increase in the data rate or if the value of the received RCB indicates a save command, the terminal checks its status to determine if the stored data rate can be supported (S350). If so, the data rate is maintained at the speed level of the previous frame (S360); otherwise, the data rate decreases by a decrease value β relative to the speed of the previous frame.

If the value of the received RCB indicates an increase command, but the state of the terminal cannot support the increased or stored data rate; or if the value of the received RCB indicates a save command, but the state of the terminal cannot support the stored data rate; or if the value of the received RCB indicates a reduction command, the terminal decreases its data rate by β relative to the speed of the previous frame. In short, the data rate can be increased, decreased or stored according to the state of the terminal, if the terminal receives an RCB indicating an increase command, but if the terminal receives an RCB indicating an save command, the data rate must be reduced or saved according to the state of the terminal, and if the terminal receives an RCB indicating a decrease command, the data rate should be reduced.

The above description relates to a terminal that is not in a handover state. In a handover state, the terminal is communicating, for example, with a serving sector and one or more non-serving sectors in the active set. An active set is a list of reference signals that are used for the current data exchange. In other words, an active set is a list of sectors that communicate with a mobile station.

When transmitting a dedicated RCB to an appropriate terminal in a handover, for example, during soft handoff, the base station and / or terminal can use one of four schemes to set a new transmission rate based on RCB information received from multiple sectors in the active set .

In the first transmission scheme, a base station controller (BSC), which controls one or more base stations (namely, BTS), generates an RCB and transmits the generated RCB to each base station in all active sectors controlled by the base station controller so that the terminal is in the zone The soft handoff received one RCB from several base stations. The difference in distance from the terminal to each base station results in a differentiation of the energy levels of each RCB received by the terminal, which combines the energy levels to obtain one RCB that satisfies the conditions to match the target error rate. Depending on the value (increase, decrease or save) received from the base station, the terminal determines the transmission rate of the next frame in accordance with steps S310-S360 of FIG. 5. For example, if the RCB value is associated with an increase in the transmission rate, the terminal may set the transmission rate equal to one of the increased, decreased, or stored speed depending on the terminal state described above. If the RCB value is associated with maintaining the transmission rate, the terminal may set the transmission rate to one of a reduced or stored rate depending on the state of the terminal. If the RCB value is associated with a decrease in the transmission rate, the terminal decreases the transmission rate in the next frame.

In the second transmission scheme, the base station controller accordingly generates an RCB for the base station of each active sector for transmission to the terminal in the soft handoff zone. In this case, the terminal receives RCB information from several base stations (e.g., BTS), which may be conflicting, and the terminal determines which RCB information to use when determining the new transmission rate. For example, if the RCB information received from any of the base stations is associated with a decrease in the transmission rate, then the terminal decreases the transmission rate, for example, in the next frame. If none of the RCB information received from several base stations is associated with a decrease in the transmission rate and there is at least one RCB information that is associated with maintaining or holding the current transmission rate, then the terminal either saves or decreases the speed transmission depending on the state of the terminal. If none of the RCB information received from several base stations has an associative association with a decrease or preservation of the transmission rate and there is at least one RCB information that is associated with an increase in the current transmission rate, then the terminal increases, stores or decreases the speed transmission depending on the state of the terminal.

6 illustrates a third handover mode data transmission scheme according to a preferred embodiment of the present invention. In the third transmission scheme, only the RCB indicating the reduction command can be transmitted to the corresponding terminal from the base station of the non-serving sector in the active set. Those. a base station associated with a non-serving sector does not transmit RCB information indicating to increase or maintain a data rate, but a base station associated with a serving sector may transmit RCB information indicating to increase, decrease or maintain a data rate for the corresponding terminal. To do this, in step S400, the terminal first determines whether an RCB indicating the reduction command is received from the base station of the non-serving sector. If the terminal receives at least one such RCB (containing the decrease command), the terminal decreases the transmission rate, as shown in step S401. If the RCB information from the non-serving sector is not associated with a decrease in the transmission rate, then the terminal checks the RCB information received from the serving base station (e.g., BTS) in S402. If the RCB information from the serving base station is to increase the transmission rate (S403), then the terminal determines the next transmission rate in accordance with steps S310-S360 of FIG. 5. If the RCB information from the serving base station is to maintain the transmission rate (S404), then the terminal determines the next transmission rate in accordance with steps S310-S360 of FIG. 5. If the RCB information from the serving base station is to reduce the transmission rate (S405), then the terminal changes the next transmission rate to a reduced speed compared to the current transmission rate.

In the fourth transmission scheme, base stations of non-serving sectors do not transmit the RCB to the corresponding terminal so that the terminal receives RCB only from the base station of the serving sector. Based on the RCB received from the serving base station, the terminal determines the next transmission rate in accordance with steps S310-S360 of FIG. 5.

As described above, base stations communicate with a single terminal. In practice, however, many active terminals are present in any cell. In order to achieve this, a dedicated RCB may be respectively generated and transmitted to each of the plurality of terminals via one co-channel. 7 shows an exemplary co-channel configuration, referred to herein as a forward link combined rate control (F-CRCCH) channel that is multiplexed with a forward link combined acknowledgment channel (F-CACKCH) for transmitting a corresponding plurality of ACK / NACK bits allocated reverse link packets transmitted from multiple terminals. The channel configuration is obtained using a repeater, a signal point mapper, and a channel transmit amplification device for each dedicated RCB in a plurality of (1-N) terminals and corresponding elements for each ACK / NACK bit. Meanwhile, a long code is generated in the long code generator for entering the decimator, and the decimator output is included in the correction calculator. The conclusions of the first and second multiplexers are the signals of the quadrature phase shift keying X _I and X _Q.

Therefore, according to the method of the present invention, the base station transmits specific data rate control information for the respective terminals, taking into account the increase in thermal noise, the state of the buffers and the state of the reverse links in order to reduce the increase in thermal noise and increase the efficiency of data transmission on the reverse link.

FIG. 8 illustrates a block diagram of a mobile station according to a preferred embodiment of the present invention.

Referring to FIG. 8, a mobile station 500 includes a processor (or digital signal processor) 510, an RF module 535, a power management module 505, an antenna 540, a battery 555, a display 515, a keypad 520, a memory 530, a SIM card 525 ( which may be optional), a 545 speaker and a 550 microphone.

A user enters information with instructions, such as a phone number, for example, by pressing keys on the keypad 520 or by voice activation using a microphone 550. Microprocessor 510 receives and processes information with instructions to perform a corresponding function, for example, dialing a phone number. Operational data may be extracted from a SIM card (Subscriber Identity Module) 525 or memory module 530 to perform a function. Moreover, the processor 510 may display information with instructions and operating information on the display 515 for reference and user convenience.

The processor 510 provides instruction information to the RF module 535 to initiate communication, for example, by transmitting radio signals containing voice communication data. The RF module 535 includes a receiver and a transmitter to receive and transmit radio signals. Antenna 540 facilitates the transmission and reception of radio signals. After receiving the radio signals, the RF module 535 can redirect and convert the signals to a modulating frequency for processing by the processor 510. The processed signals must be converted into audio or readable information output, for example, through the speaker 545.

It will be apparent to those skilled in the art that preferred embodiments of the present invention can be easily implemented using, for example, a processor 510 or another data processor or digital processing, either alone or in combination with external support logic.

Although the present invention has been described in the context of mobile communications, the present invention can also be used in any wireless communication systems using mobile devices such as PDAs and travel computers equipped with wireless capabilities. Moreover, the use of specific terms to describe the present invention should not limit the scope of the present invention to a specific type of mobile communication system, for example, cdma2000. The present invention is also applicable to other wireless communication systems using various radio interfaces and / or physical layers, for example, TDMA, CDMA, FDMA, WCDMA, etc.

Preferred embodiments may be implemented as a method, apparatus, or product of production by applying standard programming and / or manufacturing techniques to generate software, firmware, hardware, or any combination thereof. The term “production product” as used herein means code or logic implemented in hardware logic (for example, an integrated circuit, a user programmable matrix LSI (FPGA), a specialized integrated circuit (ASIC), etc.) or a computer-readable medium , for example, magnetic storage media (for example, hard disks, floppy disks, tape, etc.), optical media (CDs, optical disks, etc.), volatile and non-volatile storage devices (for example, EEPROM, ROM, EPROM, OZ U, DOSE, RAM, firmware, programmable logic, etc.). The code in a machine-readable medium is accessible and executed by the processor. The code in which the preferred embodiments are implemented may additionally be available via a transmission medium or from a file server over the network. In such cases, the product of production in which the code is implemented may comprise a transmission medium, such as a network transmission line, a wireless transmission medium, signals propagating through space, radio waves, infrared signals, etc. Of course, those skilled in the art will appreciate that many modifications can be made to this configuration without departing from the scope of the present invention, and that the product of manufacture may include any information bearing medium known in the art.

The logical implementation shown in the drawings describes specific operations as being performed in a particular order. In alternative embodiments, certain logical operations may be performed in a different order, modified, or deleted, while implementing preferred embodiments of the present invention. Moreover, the steps may be added to the above described logic while still being consistent with implementations of the invention.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention. Thus, the present invention is intended to cover the modifications and variations of this invention, provided that they are within the scope of the claims and their equivalents.

Claims (14)

1. A method for controlling an uplink data rate to a terminal in a wireless communication system during a handover for exchanging data between a network and a terminal, the method comprising the steps of: receiving a first speed control parameter from a serving base station, the first control parameter speed indicates one of the first state associated with an increase in the data rate on the uplink, the second state associated with a decrease in the data rate, and the third a condition associated with preservation of the data rate; checking whether a second speed control parameter has been received from at least one non-serving base station, the second speed control parameter indicating a fourth state associated with a decrease in the data rate; and determining a data rate based on the first and second speed control parameters, depending on whether or not the second speed control parameter is adopted. 2. The method of claim 1, wherein the data rate decreases when a second rate control parameter is adopted. 3. The method according to claim 1, wherein the second data rate is set equal to the transmission rate associated with the first speed control parameter when the second speed control parameter is not accepted. 4. The method according to claim 3, in which, when the first rate control parameter is associated with a decrease in the first data rate, the terminal decreases the data rate. 5. The method of claim 3, wherein when the first rate control parameter is associated with storing the first data rate, the terminal either decreases or stores the data rate based on the transmission characteristics of the terminal. 6. The method of claim 3, wherein when the first rate control parameter is associated with increasing the first data rate, the terminal increases, decreases, or stores the data rate based on the transmission characteristics of the terminal. 7. The method according to claim 1, wherein when at least one of the first and second speed control parameters is associated with a decrease in the data rate, the terminal decreases the data rate. 8. A method for controlling an uplink data rate to a network in a wireless communication system during a handover for exchanging data between a network and a terminal, the method comprising the steps of transmitting a first rate control parameter from a serving base station to a terminal, the first the rate control parameter indicates one of the first state associated with an increase in the data rate on the uplink, the second state associated with a decrease in the data rate, and t etego condition associated with preservation of the data rate; transmitting the second speed control parameter from the non-serving base station to the terminal only when the data rate should be reduced, the second speed control parameter indicating the fourth state associated with the decrease in the data rate; and
receive data having a data rate using at least one of the serving and non-serving base stations, the data rate being determined by the terminal based on the first and second speed control parameters, depending on whether or not the second speed control parameter is received. 9. The method of claim 8, wherein the data rate decreases when a second rate control parameter is adopted. 10. The method of claim 8, wherein the second data rate is set equal to the transmission rate associated with the first rate control parameter when the second rate control parameter is not received. 11. The method of claim 10, wherein when the first rate control parameter is associated with decreasing the first data rate, the terminal decreases the data rate. 12. The method of claim 10, wherein when the first rate control parameter is associated with storing the first data rate, the terminal either decreases or stores the data rate based on the transmission characteristics of the terminal. 13. The method of claim 10, wherein when the first rate control parameter is associated with increasing the first data rate, the terminal increases, decreases, or stores the data rate based on the transmission characteristics of the terminal. 14. The method of claim 8, in which when at least one of the first and second speed control parameters is associated with a decrease in the data rate, the terminal decreases the data rate.

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