KR20110004244A - Method of paging in a wireless communication system - Google Patents

Abstract

PURPOSE: A paging method in a wireless communication system is provided to reduce overhead due to paging related information. CONSTITUTION: A BS(Base Station) generates a paging advertisement message including a paging group ID bitmap. The paging group ID bitmap shows whether an MS paging for paging groups with the BS exists. The BS transmits the paging advertisement message to MSs. The paging advertisement message includes a field showing the number of MSs paged for a paging group for an MS which is paging.

Description

Paging method in wireless communication system {METHOD OF PAGING IN A WIRELESS COMMUNICATION SYSTEM}

The present invention relates to a wireless communication system and, more particularly, to a paging method in a wireless communication system.

First, the idle mode and the paging group of the terminal will be described.

The broadband wireless access system supports idle mode to minimize power consumption of the terminal. In the idle mode, when the UE moves in a radio link environment composed of multiple base stations, it may be capable of receiving downlink (DL) broadcast traffic without registering with a specific base station.

During the idle mode, the UE does not need to perform a handoff procedure when the base station moves in the same paging zone. Therefore, the mobile station does not have to transmit uplink information for the handoff procedure, thereby reducing power consumption.

The paging area is an area covered by a paging group composed of a plurality of base stations, and paging refers to a function of identifying a location (eg, any base station or a switching center) of the terminal when an incoming call occurs. At this time, the paging group represents a logical group. The purpose of a paging group is to provide an adjacent coverage area that can be paged in downlink if there is traffic targeting the terminal.

The paging group may include one or more base stations, and one base station may be included in one or more paging groups. Paging groups are defined in the management system. Paging groups can use paging group-action backbone network messages. In addition, the paging controller may manage a list of UEs in idle mode by using a paging-announce message, which is one of the backbone network messages, and manage initial paging of all base stations belonging to the paging group.

When the terminal requests the base station to switch to the idle mode, the base station can transfer the terminal with its paging group ID (paging group ID) can be put into the idle mode state.

Next, a paging procedure according to the prior art will be described.

If the paging controller receives a call or packet for the terminal while the terminal is in idle mode, the paging controller transmits a paging message to all base stations in the paging group, and the base stations in the paging group that receive the paging message receive the terminal. Broadcast a paging advertisement message to the network. The terminal receives the paging advertisement message transmitted by the base station during the available interval and determines whether to transition to the normal mode or remain in the idle mode. That is, when the paging controller paged itself, the paging controller enters the normal mode and communicates with the base station.

However, even when there is no paging message transmitted to the terminal, the terminal needs to receive a paging message for each paging offset, thereby causing a waste of power.

As described above, the paging method according to the prior art has a problem that the power of the terminal is wasted.

An object of the present invention is to provide a paging method that can reduce the overhead caused by the paging-related information while reducing the power consumption of the terminal.

Technical problems to be achieved in the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned above will be clearly understood by those skilled in the art from the following description. Could be.

In order to achieve the above object, in the paging method in a wireless communication system according to an aspect of the present invention, the base station is a paging group ID bitmap indicating whether there is a terminal for paging group for each of the paging group including the base station; A paging advertisement message is generated and transmitted to the terminals.

In order to achieve the above object, in the paging method in a wireless communication system according to another aspect of the present invention, after entering the idle mode, the terminal determines whether there is a terminal for paging for each of the paging groups including the base station; Receive a paging advertisement message from the base station, the paging group ID bitmap indicating.

In this case, the paging advertisement message may further include a field indicating the number of paging terminals for each paging group including the paging terminal among the paging groups including the base station.

The paging advertisement message may further include information about each of the paged terminals of each of the paging groups in which the paging terminal including the base station is located.

In addition, the information on each of the terminals may include an action code field indicating an operation requested by the base station to each of the terminals.

In addition, the paging advertisement message may further include an extension flag field indicating whether the listening interval is extended.

According to embodiments of the present invention, the power consumption of the terminal can be reduced by notifying the terminal whether or not there is a terminal paging for each paging group including the base station using the paging group ID bitmap.

The effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned above may be clearly understood by those skilled in the art from the following description. will be.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise. In addition, the terms “… unit”, “… unit”, “module”, etc. described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. have.

First, an idle state entry process and a paging process of a terminal in a wireless communication system will be described with reference to FIG. 1.

1 is a diagram illustrating an idle state entry process and a paging process of a terminal in a wireless communication system.

In idle mode, paging may be performed in units of paging groups. For example, the terminal may belong to one or multiple paging groups. A paging controller (PC) of each paging group performs paging to find a terminal when a user packet transmitted from a call or an external network to the terminal is received. In this case, the paging controller may deliver a paging message to all base stations in the paging group, and each base station that receives the paging message may perform paging by broadcasting a paging advertisement (MOB_PAG-ADV) message to the terminal.

Referring to FIG. 1, the terminal transmits a deregistration request (hereinafter referred to as a "DREG-REQ") message to a base station currently communicating in order to enter an idle mode in a normal mode (S110).

The base station receiving the deregistration request message transmits terminal information and base station information to the paging controller (S120). The terminal information may be a terminal identifier or a MAC address of the terminal, and the base station information may be a base station identifier.

The paging controller transmits paging controller related information to the base station (S130).

The base station transmits a deregistration command (hereinafter referred to as "DREG-CMD") message to the terminal in response to the deregistration request message (S140).

The DREG-CMD message may include a paging group identification, a paging offset, a paging message offset, and a paging listening interval.

The paging group ID is the ID of the paging group allocated to the terminal by the base station, the paging offset (paging offset) is the time when the terminal monitors the paging message transmitted from the paging group, the paging listening interval is the paging transmitted by the terminal from the paging group A message monitoring interval, and a paging message offset is a time point during which a terminal receives a paging message transmitted from a paging group.

After confirming the deregistration command message, the terminal enters the idle mode. The terminal in the idle mode may receive a paging message based on the paging information received through the deregistration command message.

If a call or packet for the terminal is received by the paging controller while the terminal is in the idle mode (S150), the paging controller transmits a paging message to all base stations in the paging group (S160). Then, the base stations in the main paging group receiving the paging message broadcasts a paging advertisement (PAG-ADV) message to the terminals that it manages (S170), the terminal checks the paging advertisement message, the normal mode Enter and perform communication with the base station (S180).

Next, a paging method of a terminal in a wireless communication system according to an embodiment of the present invention will be described. 2 is a diagram illustrating a paging method of a terminal in a wireless communication system according to an embodiment of the present invention.

As shown in FIG. 2, the terminal receives paging group ID information (PGID information) and a paging advertisement message from the base station during the paging listening interval.

The base station informs the terminal whether to transmit the paging group ID information through the broadcast A-MAP IE (Broadcast A-MAP IE), and if the paging group ID information is indicated to be transmitted, the paging group ID information is transmitted after the A-MAP. do.

The paging group ID information may include at least one paging group ID, a paging indicator bitmap and a paging indicator usage flag. The paging group IDs are IDs of paging groups to which the base station transmitting paging group ID information belongs, and the terminal may determine paging group IDs to determine whether the terminal moves to another paging group region.

The paging indicator bitmap indicates whether each frame included in the corresponding super frame includes a paging message. For example, if one super frame includes four frames, the paging indicator bitmap may be represented by 4 bits. If only the third frame includes a paging message, the paging indicator bitmap becomes '0010'.

For example, when the terminal receives the third frame with the paging message offset through the deregistration command message, the terminal checks the third bit of the paging indicator bitmap in the paging listening interval. If the third bit of the paging indicator bitmap is set to 1, the UE checks the paging message in the third frame. If it is set to 0, the UE determines that there is no paging message delivered to it and determines the paging message in the third frame. Do not check.

The paging indicator usage flag indicates whether the paging group ID information includes a paging indicator bitmap. That is, if the paging indicator use flag is 1, the paging group ID information includes the paging indicator bitmap. If the paging indicator use flag is 0, the paging group ID information does not include the paging indicator bitmap.

The paging group ID information may or may not include a paging indicator bitmap and a paging indicator use flag.

Table 1 shows the format of the paging group ID information when the paging group ID information includes the paging indicator bitmap and paging indicator use flag. Table 2 shows that the paging group ID information does not include the paging indicator bitmap and paging indicator use flag. If not, it indicates the format of the paging group ID information.

Syntax Size (bits) Notes Format of PGID information () { - - Num_ PGIDs 3 Number of paging group IDs Paging indicator usage flag One 0: Paging indicator bitmap is not included.
1: Paging indicator bitmap is included. for (i = 0; i <Num_PGIDs; i ++) { - -    PG ID 16 Paging group identifier } - - if (Paging indicator usage flag == 1) { - - Paging indicator bitmap 4 * Number of PGIDs The paging indication bitmap size is 4 bit and is assigned per paging group. Each bit refers to a frame within a super frame and indicates the presence of the AMS's paging message within the frame.
0x00: If this bit is set to 1, AMS's paging message is transmitted in 1 ^st frame during the paging listening interval (1 superframe).
0x01: If this bit is set to 1, AMS's paging message is transmitted in 2 ^nd frame during the paging listening interval (1 superframe).
0x02: If this bit is set to 1, AMS's paging message is transmitted in 3 ^rd frame during the paging listening interval (1 superframe).
0x03: If this bit is set to 1, AMS's paging message is transmitted in 4 ^th frame during the paging listening interval (1 superframe). } - - } - -

Syntax Size (bits) Notes Format of PGID information () { - - Num_ PGIDs 3 Number of paging group IDs for (i = 0; i <Num_PGIDs; i ++) { - -    PG ID 16 Paging group identifier } - - } - -

As shown in FIG. 2, the terminal receives a paging advertisement message from the base station at the paging message offset of the paging listening interval.

Table 3 shows the paging advertisement message when the paging indicator usage flag is set to 1 and the paging group ID information includes the paging indicator bitmap. Table 4 shows the paging group usage information as the paging group ID information. Indicates a paging advertisement message when the indicator bitmap is not included or the paging group ID information does not include the paging indicator use flag and the paging indicator bitmap as shown in Table 2.

Syntax Size (bit) Notes AAI_PAG-ADV_Message format () { Management Message Type = TBD 8 AAI_PAG-ADV message for (i = 0; i <Num_Positive_Paging_Group_IDs; i ++) { - Num_Postive_Paging_Group_IDs is the number of bits set to one in the Paging indicator bitmap     Num_AMSs 8 Number of paged AMSs for (j = 0; j <Num_AMS; j ++;) { temporary identifier TBD Temporary Identifier of the AMS Action code 2 Paging Action instruction to AMS
0b00 = Perform network re-entry
0b01 = Perform ranging to establish location
0b10 = Perform LBS measurement
0b11 = Reserved } } Extension flag One Extension flag is used to indicate the presence of other paging message in the subsequent frame.
0: Current paging message is last paging message within paging listening interval.
1: Other paging message is transmitted in the subsequent frame. }

Syntax Size (bit) Notes AAI_PAG-ADV_Message_format () { - -   Management Message Type = TBD 8 -   Paging_Group_IDs bitmap variable The size of Paging_Group_IDs bitmap is the number of paging group IDs in the PGID info message, each bit in the bitmap indicates:
0: the paging information for the corresponding PGID is not included
1: the paging information for the corresponding PGID is included   For (i = 0; i <Num_Postive_Paging_Group_IDs; i ++) { - Num_Postive_Paging_Group_IDs is the number of bits set to one in the Paging_Group_IDs bitmap     Num_AMSs 8 Number of paged AMSs     For (j = 0; j <Num_AMSs; j ++) { - -       Temporary Identifier 10 Temporary identifier, paging cycle, and paging offset are used to uniquely identify an AMS in the idle mode in a particular paging group       Paging Cycle 4 Paging cycle consists of paging unavailable and paging available interval       Action code 2 Paging Action instruction to AMS
0b00 = Perform network re-entry
0b01 = Perform ranging to establish location
0b10 = Perform LBS measurement
0b11 = Reserved     } - -   } - -   Extension flag One 0 = There is no remaining part of this paging message
1 = The remaining part of this paging message will be transmitted in the subsequent frame or sub-frame } - -

As shown in Table 4, the Use Paging Indicator flag is set to 0 so that the paging group ID information does not contain the paging indicator bitmap, or the paging group ID information does not include the paging indicator use flag and paging indicator bitmap, as shown in Table 2. The paging advertisement message includes a paging group ID bitmap (Paging_Group_IDs bitmap).

The paging group ID bitmap indicates whether there is a terminal paging for each paging group including the base station. The size of the paging group ID bitmap is equal to the number of paging groups (Num_PGIDs) of paging group information, which is the number of paging groups including the base station. For example, if there are four paging groups to which the base station belongs, the size of the paging group ID bitmap is 4, and each bit indicates whether there is a terminal to be paged among terminals belonging to each of the paging groups. If there is a terminal being paged, the corresponding bit is set to 1, and if there is no terminal being paged, the corresponding bit is set to 0.

In Tables 3 and 4, Num_Positive_Paging_Group_IDs means the number of paging groups in which a paging terminal is located among paging groups to which a base station belongs. That is, when the paging advertisement message is shown in Table 4, Num_Positive_Paging_Group_IDs is equal to the number of bits set to 1 in the paging group ID bitmap.

When the paging advertisement message is shown in Table 3, Num_Positive_Paging_Group_IDs is the number of paging groups in which at least one bit of 4 bits is not 0 in the paging indicator bitmap of Table 1. For example, if four paging groups are included in the base station, four paging indicator bitmaps (4 bits) are included. At this time, if all four bits corresponding to one paging group are 0 and each of the four bits corresponding to the remaining three paging groups is one bit, Num_Positive_Paging_Group_IDs is three.

The paging advertisement message includes the number of terminals paging (Num_AMSs) for each paging group in which the paging terminal of the paging group to which the base station belongs is located.

The paging advertisement message includes a temporary identifier, a paging cycle, and an action code for each paged terminal of each paging group in which a paging terminal among the paging groups to which the base station belongs is located. can do.

The action code represents an operation requested by the base station to the terminal. That is, as shown in Tables 3 and 4, '0b000' may request network re-entry, '0b01' may request location update from the terminal, and '0b10' may request LBS measurement from the terminal.

The extension flag indicates whether the listening section is extended. If the base station does not transmit all of the paging message during the listening interval, the base station extends the listening interval to transmit the remaining portion of the paging message. Therefore, when the extension flag is set to '1', the terminal extends the listening interval and monitors the following frame to receive a paging message. After the reception of the paging message is completed, the terminal ends the listening section.

Embodiments according to the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In a hardware implementation, a paging method according to an embodiment of the present invention may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), and programmable logic devices (PLDs). ), Field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, and the like.

In the case of implementation by firmware or software, the paging method according to an embodiment of the present invention may be implemented in the form of a module, procedure, function, etc. that performs the functions or operations described above. The software code may be stored in a memory unit and driven by a processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various known means.

It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit and essential features of the present invention. Accordingly, the above detailed description should not be construed as limiting in all aspects and should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

It is obvious that the claims may be combined to form an embodiment by combining claims that do not have an explicit citation relationship in the claims or as new claims by post-application correction.

1 is a diagram illustrating an idle state entry process and a paging process of a terminal in a wireless communication system.

2 is a diagram illustrating a paging method of a terminal in a wireless communication system according to an embodiment of the present invention.

Claims (10)

A paging method of a base station in a wireless communication system, Generating a paging advertisement message including a paging group ID bitmap indicating whether there is a terminal paging for each paging group including the base station; And Transmitting the paging advertisement message to terminals. The method of claim 1, The paging advertisement message further comprises a field indicating the number of paging terminals for each paging group in which the paging terminal among the paging groups including the base station. The method of claim 1, The paging advertisement message may further include information about each of the paged terminals of each paging group in which the paging terminal among the paging groups including the base station is located. The method of claim 1, The information on each of the terminals comprises a Action Code field indicating an operation requested by the base station to each of the terminals. The method of claim 1, The paging advertisement message further includes an extension flag field indicating whether the listening interval is extended. In the paging method of the terminal in a wireless communication system, Entering an idle mode; And Receiving a paging advertisement message from the base station including a paging group ID bitmap indicating whether there is a terminal paging for each of the paging groups including the base station. The method of claim 6, The paging advertisement message further comprises a field indicating the number of paging terminals for each paging group in which the paging terminal among the paging groups including the base station. The method of claim 6, The paging advertisement message may further include information about each of the paged terminals of each paging group in which the paging terminal among the paging groups including the base station is located. The method of claim 6, The information on each of the terminals comprises an action code field indicating an operation requested by the base station to each of the terminals. The method of claim 6, The paging advertisement message further includes an extension flag field indicating whether the listening interval is extended.

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