KR20050024998A - Method for decreasing used power of mobile system for wireless data service - Google Patents

Abstract

PURPOSE: A method for reducing power consumption of a mobile terminal for a wireless data service is provided to reduce power consumption of a mobile terminal in a control hold mode by demodulating a packet data control channel only when necessary by using a QPCH(Quick Paging Channel). CONSTITUTION: A mobile terminal is transited from an active mode to a CHM(Control Hold Mode)(210). The mobile terminal wakes up(220) and monitors a QPCH(230) to check whether its paging indicator information(bit) has been transmitted from a base station system(240). If its paging indicator information is checked, the mobile terminal stops monitoring of the QPCH, checks a paging indication message from the transmitted message and decodes a PDCCH(Packet Data Control Channel) from a designated point(250). When decoding of the PDCCH is completed, the mobile terminal checks control information included in the PDCCH(260). The mobile terminal checks whether the control information is for updating data for operating a packet data channel(270). If the control information is not for updating data for operating the packet data channel, the mobile terminal checks whether the control information is for transition to the active mode(280). If the control information is for transition to the active mode, the mobile terminal is transited to the active mode and terminates the QPCH monitoring operation(290).

Description

Method for reducing power consumption of a mobile terminal for wireless data service {Method for decreasing used power of mobile system for wireless data service}

The present invention relates to a wireless data service method of a mobile communication system, and more particularly, to a method for reducing power consumption of a mobile terminal in a wireless data service.

In general, for wireless data service between a base station and a terminal in a mobile communication system, a channel connection of a wireless section should be made. Types of channels for such channel access are divided into a forward channel and a reverse channel. In general, the IS-95 includes a pilot channel, a pilot channel, a sync channel, a paging channel, and a traffic channel as a forward channel, and an access channel as a reverse channel. It consists of a communication channel. Among these channels, a call channel is a channel for transmitting a message such as additional information, a paging command for a specific mobile terminal, and a channel assignment to a mobile terminal in a service area.

The call channel divides the system time into smaller slots of 80 ms units with 2048 cycles. This is called the call channel slot. The mobile terminal may use a slotted mode that monitors the calling channel only for a specific slot and does not monitor the paging channel for the remaining slot cycles to reduce its power consumption. In order to monitor the call message, the mobile terminal must monitor the call channel periodically during the assigned call channel. Because typical call messages are sent over relatively long, medium to low rate channels, processing during each call channel slot requires considerable time and signaling resources. Thus, significant power consumption is required to complete this, shortening the period of time for a battery of a given capacity to remain in standby mode.

On the other hand, the mobile communication system has evolved to support not only voice service but also data service for video communication and the Internet as technology has developed. A base station in a mobile communication system supporting such a service typically separates a circuit channel for a voice service and a packet channel for a data service, and allocates and operates the remaining packet resources except for the radio resource used for the circuit channel. Here, the radio resources used in the base station include a power amount, a number of Walsh codes, a time slot, and the like.

In such a forward packet data channel (hereinafter referred to as F-PDCH) for transmitting packet data, a section in which data is transmitted and a section in which data is not transmitted may be irregular depending on burst traffic characteristics of a data service. have. In addition, for example, it is necessary to improve Outage Probability, Sytem Capacity, Scheduler's multiplexing effect, and increased battery consumption of mobile terminals, which are generated by using dormant mode when operating F-PDCH in CDMA 2000 system. .

Accordingly, the mobile terminal and the base station use the control hold mode to minimize the consumption of radio resources and power consumed by the base station and the mobile terminal. In other words, the control hold mode (CHM) is shifted in a section where data is not normally transmitted, and when the data is generated, the control hold mode (CHM) is shifted to the active mode (AM). When the mobile terminal is in the active mode through the transition operation, the mobile terminal decodes both a packet data channel and a packet data control channel (PDCCH) for transmitting information for controlling the transmitted packet data. On the other hand, when the mobile terminal is in the control hold mode, only the packet data control channel is decoded. The packet data control channel is a channel that informs the subpacket format of the packet data channel transmitted at the same moment or transmits different types of control information to the mobile terminal.

However, in order to know when the mobile station will demodulate the packet data channel in an active state, the mobile station always has a length of 1.25ms, 2.5ms, and 5ms in one of 29.6kbps, 14.8kbps and 7.4kbps in the control hold mode. In all cases, the packet data control channel (PDCCH) is demodulated. As the mobile terminal always demodulates three frame lengths, the power consumption of the mobile terminal increases accordingly.

Accordingly, an object of the present invention is to provide a method for reducing power consumption of a mobile terminal when operating a packet data channel for transmitting wireless data.

Another object of the present invention is to provide a method of demodulating a packet data control channel only when necessary by using an emergency call channel to reduce power consumption of the mobile terminal when the mobile terminal is in the control hold mode state.

The method for achieving the object of the present invention, in a mobile communication system having a plurality of base stations for wireless data service with the mobile terminal, the mobile terminal is consumed by a wireless data service with the plurality of base stations A method of reducing power, the method comprising: transitioning to a control hold mode in a section in which no base station transmits packet data during an arbitrary data base and the wireless data service; And a process of monitoring an emergency call channel only for a preset slot, and a packet data control channel including control information transmitted in synchronization with the packet data from a designated time point according to its call indicator information included in the emergency call channel. And decoding the decoded packet data. It characterized by comprising the step of performing the service according to the control information included in the control channel.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The present invention described below uses an emergency call service to reduce the battery power consumption of the mobile terminal to increase the call waiting time. An emergency call channel is established between the mobile terminal and the base station system for such an emergency call service. The emergency call channel is generally used in the idle state. In the present invention, the emergency call channel used in the idle state is used in the control hold mode for demodulating only the packet data control channel. In the present invention described below, a case in which the emergency call channel used in the idle state is used as it is will be described. However, in some cases, other channels may be used that can function as emergency call channels.

When the mobile terminal is in the idle state, the emergency paging channel (QPCH) will be described in detail with reference to the accompanying drawings.

The emergency call channel operation technology is introduced in the CDMA 2000 standard, and it indicates in advance when a mobile terminal should receive a full paging channel slot that the mobile terminal should receive before sending a page message to the mobile terminal. This is how you tell. A base station uses an emergency call channel to transmit a mobile terminal operating in a slot mode in an idle state in a next forward common control channel (F-CCCH) or paging channel (PCH) slot. It informs in advance that it must receive the starting forward common control channel or calling channel. That is, the emergency call channel transmits an indicator indicating whether there is a message to be received in the paging slot designated to the mobile terminal.

The emergency call channel operates in a slot mode in which the mobile station monitors the call signal only during a specific slot promised by the base station and does not operate in other slots to reduce power consumption of the mobile station.

1 illustrates an emergency call channel when a mobile terminal is in an idle state in a mobile communication system.

As shown in FIG. 1, the total call channel cycle (system time) is 128 cycles, that is, 2048 slots, 1 cycle is 16 slots, 1 slot is 80 ms, and 1 cycle is 1.28 seconds. The slot is called a call channel slot (PCH / F-CCCH Slot).

 The slot period of the emergency call channel is 80ms similar to the call channel slot, and one period is divided into small slots of 20ms.

When the mobile terminal operating in the slot mode and operating the emergency call channel transitions from the initialization state 10 to the idle state 20, the mobile terminal 100 ms ahead of the slot of the call channel to be monitored (50). Wake up). Here, the wake-up may be known by detecting an indicator bit in a message transmitted through a forward wake-up channel allocated between the mobile station and the base station. When the user wakes up according to the detected indication information, the mobile terminal supplies power to the demodulation related circuit and decodes the dedicated control channel.

Hereinafter, by using the emergency call channel or another channel having the emergency call channel function applied when the mobile terminal is in the idle state as described above, the mobile terminal decodes the packet control channel only when necessary in the control hold mode and consumes the data service. A method for reducing power will be described. The structure of the emergency call channel used in this case will be described with reference to the drawings.

2 is a diagram illustrating the structure of an emergency call channel according to an embodiment of the present invention.

The mobile terminal is currently transitioned from the active mode 110 to the control hold mode 120 (Control Hold Mode: CHM). The mobile terminal in the control hold mode 120 state monitors the emergency call channel.

Referring to FIG. 2, a forward packet data channel and a packet data control channel are set between a mobile station and a base station, and a cycle (system time) of the entire forward packet data channel and the packet data control channel is 128 cycles, that is, 2048 slots, and 1 cycle is 16slots (# 0 ~ # 15), 1slot is 80ms, 1slot cycle is 1.28 seconds. One slot of 80 ms of the packet data control channel is divided into 5 ms (#a to #p) units.

The emergency call channel is divided into a slot cycle of 80 ms, and the 80 ms cycle is called an emergency call channel slot, and one emergency call channel slot is divided into 20 ms, that is, four frames. In this case, the mobile terminal wakes up at the time 150 when the emergency call channel is operated in the idle state 20. That is, the emergency call channel is monitored starting from the start point of the 20ms slot of slot period index 4 of the emergency call channel. An arrow from the emergency call channel index 4 of FIG. 2 to the index a of the packet data control channel represents the wake-up time 150 of the mobile terminal.

As such, new fields should be added to the Layer 3 message of the CDMA 2000 system for using the emergency call channel when the mobile terminal operates the forward packet data channel for data service in the control hold mode 120. In addition, the control hold mode 120 stores data in the terminal to know whether to monitor the emergency call channel. These newly added fields are the "QPCH_CHM_SUPPORTED" field indicating that the emergency hold channel is supported in the control hold mode 120 and the "CHM_SLOT_CYCLE_INDEX" field indicating the slot cycle index for the control hold mode 120.

The messages to be described below are messages to which new fields are added when the mobile terminal uses the emergency call channel in the control hold mode, and descriptions of other fields except fields added to the messages to be described later will be omitted.

The "QPCH_CHM_SUPPORTED" field and the "CHM_SLOT_CYCLE_INDEX" field are added to the registration message (RGM). The "QPCH_CHM_SUPPORTED" field and the "CHM_SLOT_CYCLE_INDEX" field are also added to an Origination Message (ORM) and a Page Response Message (PRM). Extended System Parameter Mesage (ESPM), MC-RR Parameters Message and Terminal Information add a "QPCH_CHM_SUPPORTED" field.

An operation of monitoring the emergency call channel by the mobile terminal in order to reduce power consumption of data service between the mobile station and the base station system in the control hold mode using the emergency call channel having such a structure will be described below. Same as

3 is a flowchart illustrating an operation of monitoring an emergency call channel of a mobile terminal according to an embodiment of the present invention.

The mobile terminal uses the emergency call channel of the sector selected as the best serving sector among the active sets in the traffic state.

In step 210, the mobile terminal transitions from the active mode 110 to the control hold mode 120. Then, in step 220, the mobile terminal in the control hold mode 120 state wakes up. At this time, the mobile terminal wakes up at a time 150 that is 60ms later than the time (100ms) 50 wake-up in the idle state 20. Then, in step 230, the emergency call channel is monitored. When the mobile station monitors the emergency call channel, the mobile station stops decoding the packet data control channel. That is, in the control hold mode, the terminal monitors only the emergency call channel and does not decode the packet data channel.

In step 240, the mobile station monitors the emergency call channel and checks whether there is its own call indicator information transmitted from the base station system. That is, the call indicator information included in the message is checked. This call indicator information is specified in advance in the base station system and transmitted. That is, the base station system sets the MAC_ID (8-bit) th bit from the start point (slot index 4) of the 20ms slot to 1 using the MAC_ID assigned to the terminal to designate the call indicator information of a specific mobile terminal. Let's do it. The base station system transmits the set call indicator to the mobile terminal through the emergency call channel. This operation repeats three times in a 255-bit period during a 20ms slot, using three call indicators and setting two or more of the three to one.

If the call indicator information is not confirmed in step 240, the mobile terminal stops monitoring the emergency call channel in step 245 and continues to decode the packet data control channel. On the other hand, in step 250, the mobile station stops monitoring the QPCH and then checks a call instruction message in the transmitted message thereof, and decodes the PDCCH from a specified time point. In this case, the PDCCH decoding time is set in advance as shown in Table 1 below. Table 1 below shows a time point at which the mobile station starts to decode the PDCCH according to the call indicator combination.

P1 P2 P3 PDCCH Slot 0 One One a One 0 One e One One 0 i One One One m

If a call supporter with a 255-bit period is called P1, P2, and P3, the base station system sets the call indicator three times so as to correspond to the P1, P2, and P3 as described above. The mobile station detects the call indicators set from the base station and decodes the PDCCH from the time point specified in Table 1. For example, when P1, P2, and P3 are designated as 1, 0, and 1, referring to Table 1, since the PDCCH slot is set to the index "e", the PDCCH can be decoded from the index "e" point. Here, the call indicator information (Indicator bit) of the emergency call channel is set in the following case so that the base station system requests PDCCH decoding from the mobile station through the emergency call channel. This is the case where the mobile terminal transmits control data for operating the packet data channel to the packet data control channel, and when the mobile terminal starts to decode the packet data control channel and needs to transition to the active mode 110.

When the decoding of the packet data control channel is completed, in step 260, the mobile station checks the control information included in the PDCCH. As a result of the check, in step 270, the mobile terminal checks whether the control information is information for updating data for operating a packet data channel. In this case, if the data update means, the mobile terminal updates the data in step 275 and proceeds to step 230. On the other hand, in step 280, the mobile station determines whether the control information is information for start of PDCH decoding, that is, transition to active mode. In this case, if the mobile station does not transition to the active mode, the mobile terminal proceeds to step 220 and continuously monitors the emergency call channel. On the other hand, when the transition to the active mode 110, the mobile terminal transitions to the active mode 110 and terminates the emergency call channel monitoring operation in step 290. Subsequently, the mobile terminal in the active mode 110 decodes the packet data channel to check the serviced data.

When the mobile station transitions to a dormant state (not shown) in the control hold mode 120 during the emergency call channel monitoring, the mobile terminal stops the emergency call channel monitoring. When the mobile terminal is handed off (Cell Switching) in the control hold mode 120, the emergency call channel monitoring is stopped and the packet data control channel is decoded.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by the equivalents of the claims.

As described above, the present invention can reduce the power consumption of the mobile terminal by using the emergency call channel and the channel having the function of the emergency call channel in the control hold mode, thereby extending the call waiting time and extending the battery life. It can work.

1 is a diagram illustrating an emergency call channel when a mobile terminal is in an idle state in a mobile communication system;

2 is a diagram illustrating the structure of an emergency call channel according to an embodiment of the present invention;

3 is a flowchart illustrating an operation of monitoring an emergency call channel of a mobile terminal according to an embodiment of the present invention.

Claims (6)

In a mobile communication system having a plurality of base stations for providing a wireless data service with a mobile terminal, the method of reducing the power consumed by the mobile terminal by the wireless data service with the plurality of base stations, Transitioning to a control hold mode in a section in which the base station does not transmit packet data during any one of the base stations and the wireless data service; Periodically waking up in the control hold mode to monitor an emergency call channel only for a predetermined slot with the base station; Decoding a packet data control channel including control information transmitted in synchronization with the packet data from a designated time point according to its call indicator information included in the emergency call channel; And performing a corresponding service according to control information included in the decoded packet data control channel. The method of claim 1, wherein the performing of the service according to the control information comprises: When the control information is information indicating a transition to the active mode, transitioning from the control hold mode to the active mode; Stopping monitoring the emergency call channel as it transitions to the active mode, and decoding the packet data channel transmitting the wireless data. The process of claim 2, wherein the performing of the service according to the control information comprises: And if the control information is information indicative of an update, updating the radio data and continuously monitoring an emergency call channel. The method of claim 1, And when the mobile station transitions to the control hold mode, the mobile station wakes up a predetermined time before the packet data control channel to be demodulated and monitors the emergency call channel. The method of claim 4, wherein The predetermined time is 40 ms. The method of claim 1, The call indicator information is a set of call indicators preset in the base station, characterized in that the information indicating the decoding time of the packet data control channel.