KR20050091482A - Method for scanning and ranging neighbor base stations during sleep mode - Google Patents

Abstract

According to the present invention, a terminal transitions to a sleep mode, a step of receiving a message including information on whether to maintain a sleep mode from a base station during a predetermined listening period of the sleep mode, and after the listening section is repeated at least one of the neighboring base stations The present invention relates to a neighboring base station scanning and ranging method including performing scanning and ranging of the mobile stations, and supports sleep mode to reduce power consumption of the terminal and to perform handover when necessary even during sleep mode. It has the effect of making it possible.

Description

Method for Scanning and Ranging Neighbor Base Stations During Sleep Mode {Method for Scanning and Ranging Neighbor Base Stations during Sleep Mode}

The present invention relates to a method for scanning and ranging of neighboring base stations in a broadband wireless access system. More particularly, the present invention relates to a method for scanning and ranging of neighboring base stations so that the terminal can perform handover during sleep mode. It is about.

According to the related art, a sleep mode is provided to reduce power consumption of a mobile subscriber station (MSS) while not transmitting data. Meanwhile, in the normal operation mode in which data transmission is being performed, the neighboring base stations are scanned and initial ranging to perform handover.

1 is a flowchart illustrating a sleep mode performing method according to the prior art. Referring to FIG. 1, the terminal transmits a sleep mode request message to a base station in order to operate in a sleep mode (101). The base station transmits a sleep mode grant message in response to the sleep mode request message (102).

In this case, the sleep mode permission message includes information on the size of the initial sleep window and the size of the last sleep window and information on the listening interval. The terminal calculates a time interval to maintain the sleep mode using an exponential increase algorithm within the range of the initial sleep window and the last sleep window.

The terminal, which is in the sleep mode for the size of the initial sleep window, receives the sleep mode indication message during the listening interval (Listing Interval) (103). The sleep mode indication message includes information on whether the terminal keeps the sleep mode or switches to the normal mode.

On the other hand, when the sleep mode indication message indicates the sleep mode maintenance, the terminal determines the next sleep mode period using the exponential increase algorithm, and receives a sleep mode indication message from the base station during the listening period after the sleep mode period ends. .

When the sleep mode is continuously performed, when the size of the last sleep window is reached, the terminal no longer calculates the size of the sleep window using an exponential increase algorithm, and performs the sleep mode based on the size of the last sleep window. Repeat the sleep mode indication message through the listening section.

According to the conventional technology, there is no problem of scanning and initial ranging of neighbor base stations during the sleep mode, and thus there is a problem in that handover cannot be performed during the sleep mode.

The present invention has been proposed to solve the above problems, and an object thereof is to provide a method for scanning and ranging to neighboring base stations to enable handover during sleep mode.

In accordance with another aspect of the present invention, there is provided a method for scanning and ranging in a neighboring base station, the method comprising: switching to a sleep mode by a terminal, and including information on whether a sleep mode is maintained from a base station during a predetermined listening period among the sleep modes; Receiving a message and performing a scanning and ranging of neighboring base stations after repeating at least one listening interval.

In another aspect, the present invention provides the steps of the terminal transmitting a sleep mode request message to the base station, receiving a sleep mode permission message from the base station and switching to a sleep mode, and whether the sleep mode is maintained from the base station for a certain listening period during the sleep mode. Receiving a message including information on, and after the listening section is repeated at least one, performing the scanning and ranging of the neighboring base stations and maintaining a sleep mode according to the scanning and ranging results Switching to the normal mode to perform the handover.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a flowchart illustrating a base station scanning and ranging method in a sleep mode according to the present invention. Referring to FIG. 2, the terminal transmits a sleep mode request message to a base station in order to operate in a sleep mode (201). The base station transmits a sleep mode grant message in response to the sleep mode request message (102).

In this case, the sleep mode permission message may include information on the size of the initial sleep window and the size of the last sleep window, information on a listening interval, information on a scanning period, and a scanning interval.

Table 1 below is an embodiment of a configuration of a sleep mode permission message.

Syntax Size Notes MOB_SLR_Message_Format () { Management message type = 46 8 bits Sleep-approved 1 bit 0: Sleep-mode request denied If (Sleep-approved == 00) { After-REQ-action 1 bit 0: The MSS may retransmit the MOB_SLP-REQ message after the time duration (REQ_duration) given by the BS in this message1: The MSS shall not retransmit the MOB_SLP REQ-duration 4bits Time duration for case where After-REQ-action value is 0. reserved 2 bits } else { Start frame 7bits initial-sleep window 6bits final-sleep window 10bits listening interval 6bits SLPID 10bits } }

The terminal calculates a time interval to maintain the sleep mode using an exponential increase algorithm within the range of the initial sleep window and the last sleep window.

The terminal, which maintains the sleep mode for the size of the initial sleep window, receives the sleep mode indication message during the listening interval (203). The sleep mode indication message includes information on whether the terminal keeps the sleep mode or switches to the normal mode.

Table 2 below shows an embodiment of a configuration of a sleep mode indication message.

Syntax Size TRF-IND_Message_Format () { Management message type = 47 8bits SLPID bit-map Variable }

On the other hand, when the sleep mode indication message indicates the sleep mode maintenance, the terminal determines the next sleep mode period using the exponential increase algorithm, and receives a sleep mode indication message from the base station during the listening period after the sleep mode period ends. .

When the sleep mode is continuously performed, when the size of the last sleep window is reached, the terminal no longer calculates the size of the sleep window using an exponential increase algorithm, and performs the sleep mode based on the size of the last sleep window. Repeat the sleep mode indication message through the listening section.

As such, when only the sleep mode is performed and the listening period is repeated, scanning and ranging for handover cannot be performed. Therefore, in the present invention, when the sleep mode is performed and the listening interval is repeated a predetermined number or more times, the terminal can perform scanning and ranging of neighboring base stations.

That is, the terminal acquires information on the scanning period and the scanning interval through the sleep mode permission message. When the sleep mode is performed and the listening interval is repeated a predetermined number of times according to the scanning period information, the base station information message is received from the base station (205). The base station information message includes information about base stations around the current terminal.

Table 3 below is an embodiment of a configuration of a base station information message.

Configuration Change Count 8 bits N_NEIGHBORS 8 bits For (j = 0; j <N_NEIGHBORS; j ++) Neighbor BS-ID 48 bits Physical Frequency 32 bits TLV Encoded Neighbor information Variable TLV specific

The terminal receiving the base station information message performs scanning and ranging on neighboring base stations during the scanning interval (206a, 206b). The ranging terminal determines whether handover should be performed according to the magnitude of a signal transmitted from neighboring base stations. When handover is performed, a handover request message is transmitted to the base station (207), and the terminal transitions to the normal mode to perform the handover. On the other hand, if the handover is not performed, the sleep mode continues.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

As described above, the present invention not only reduces power consumption of the terminal by supporting the sleep mode, but also enables the handover to be performed when necessary even during the sleep mode.

1 is a flowchart illustrating a sleep mode performing method according to the prior art.

2 is a flowchart illustrating a base station scanning and ranging method in a sleep mode according to the present invention;

Claims (4)

The terminal transitioning to a sleep mode; Receiving a message including information on whether to maintain a sleep mode from a base station during a predetermined listening period of the sleep mode; And Performing scanning and ranging on neighboring base stations after repeating at least one listening section. Peripheral base station scanning and ranging method comprising a. The method of claim 1, Measuring the strength of a signal of a neighboring base station according to the scanning and ranging; And Performing a handover procedure by maintaining a sleep mode or switching to a normal mode according to the measured result; Peripheral base station scanning and ranging method comprising a. The terminal sending a sleep mode request message to the base station; Receiving a sleep mode grant message from the base station and switching to a sleep mode; Receiving a message including information on whether to maintain a sleep mode from a base station during a predetermined listening period of the sleep mode; Performing at least one repeating listening section, and then performing scanning and ranging on neighboring base stations; And Maintaining a sleep mode according to the scanning and ranging result or switching to a normal mode to perform a handover Peripheral base station scanning and ranging method comprising a. The method of claim 3, wherein The sleep mode permission message includes neighboring base station scanning and ranging, wherein the listening section repeats the information about how many times the neighboring base stations are scanned and information about the size of the scanning mining interval. Way.