KR20060029060A - Method for instructing operation of mobile terminal in sleep mode - Google Patents

Abstract

The present invention relates to a method for transmitting a motion of a mobile terminal in a sleep mode using a sleep ID in a broadband wireless access system. The base station uses sleep ID to terminate a sleep mode and / or a terminal in a sleep state. Alternatively, the length of the traffic notification message can be greatly reduced by indicating periodic ranging.

Sleep Mode, Sleep ID, Ranging, Traffic Notification Message

Description

Operation method of sleep mode mobile terminal {METHOD FOR INSTRUCTING OPERATION OF MOBILE TERMINAL IN SLEEP MODE}

1 is a diagram illustrating a sleep request (MOB-SLP-REQ) message delivered by a user equipment to a base station;

2 is a diagram illustrating a sleep response (MOB-SLP-RSP) message transmitted from a base station to a user equipment.

3 illustrates a conventional traffic notification (MOB-TRF-IND) message.

Figure 4 is a signal flow diagram showing the operation of the conventional sleep mode.

5 is a view showing an example of a traffic notification (MOB-TRF-IND) message used to indicate the operation of the terminal in the present invention.

The present invention relates to a broadband wireless access system, and more particularly, to a method for instructing an operation of a mobile terminal in a sleep mode.

The broadband wireless access system supports a sleep mode in order to minimize power consumption of a mobile terminal (hereinafter referred to as a terminal). The terminal in the sleep mode operates according to the sleep interval which increases at a constant rate.

In general, the sleep period is composed of a listening window (Listening Window) and the sleep window (Sleep Window). The listening period is fixed by the sleep request and the sleep response message. During the listening period, the UE indicates whether there is downlink traffic to be received by the broadcast management MAC management message transmitted from the base station or whether ranging should be performed to maintain uplink communication and maintain proper downlink coding type according to signal quality. Receive. The sleep period is a period in which the terminal receives only a minimum downlink signal from the base station for power saving. During this period, the terminal performs ranging for maintaining uplink communication and maintaining proper downlink coding type according to signal quality.

The sleep mode operation provides MAC management messages such as a sleep request (MOB-SLP-REQ) message, a sleep response (MOB-SLP-RSP) message, and a traffic notification (MOB-TRF-IND) message. By receiving.

That is, the terminal requests a sleep mode by transmitting a sleep request (MOB-SLP-REQ) message as shown in FIG. 1 to the service base station. The MOB-SLP-REQ message includes a sleep period and a listening period as a MAC management message. do. In response to the MOB-SLP-REQ message, the serving base station transmits a sleep response (MOB-SLP-RSP) message as shown in FIG. 2 to the terminal. The MOB-SLP-RSP message includes sleep mode related information such as whether to allow sleep mode, sleep period, listening period, and sleep ID. In particular, the base station assigns a unique sleep ID (SLPID) to the terminal when allowing the terminal to switch to the sleep mode.                         

Subsequently, the service base station instructs an operation to be performed by the terminal in the sleep mode using a broadcast notification (MOB-TRF-IND) message as shown in FIG. 3. In this case, the operation to be performed by the terminal is as follows. It can be divided into branches.

The terminal stays in the sleep mode (sleep bitmap indicator 00).

Exit sleep mode immediately (sleep bitmap indicator 01).

Perform periodic ranging and switch back to sleep mode (sleep bitmap indicator 10).

Perform periodic ranging and exit sleep mode (sleep bitmap indicator 11).

Here, the sleep bitmap indicator indicates two bits on the sleep bitmap.

In order to indicate the operations of the terminal as described above, the base station may use a sleep bitmap (SLPID bit-map) based on the sleep ID (SLPID) or use the lower 12 bits of the short basic CID of the terminal. .

First, when using a sleep bitmap, the sleep bitmap is allocated 2 bits for each sleep ID in the order of sleep ID (SLPID). In this case, since the sleep ID may have a maximum of 1024 values, the sleep bitmap has a maximum length of 1024 * 2 = 2048 bits, that is, 256 bytes. Therefore, the terminal having the corresponding sleep ID can read a 2-bit bitmap in accordance with its sleep ID order.

Next, when using the default connection ID, the base station can only indicate the operation of the terminal to end the sleep mode of the four operations. That is, the MOB-TRF-IND message includes only basic connection IDs of terminals that need to end the sleep mode.

4 is a view showing the operation of the conventional sleep mode. 4 illustrates an operation in which the terminal requests the base station to switch to the sleep mode, maintains the sleep mode, and ends the sleep mode by generating downlink traffic.

First, the MSS sets values such as an initial sleep period N1, a last sleep period N2, and a listening period L in a sleep request (MOB-SLP-REQ) message, and then transfers the values to the base station BS. To switch to sleep mode. When the terminal MS allows the sleep mode switching, the base station BS sleeps in which an initial sleep period N1, a last sleep period N2, a listening period L, and a sleep mode switch start time M are set. A response (MOB-SLP-RSP) message is transmitted to the MSS.

Therefore, when the sleep mode switch start time M reaches, the MSS maintains the sleep mode for the first sleep period N1. After that, when the initial sleep period (M) expires, the terminal receives a traffic notification message (MOB-TRF-IND) from the base station (BS) during the listening period (L '), if there is no downlink traffic directed to it (Negative indication) Maintain sleep mode for a period (2 * N) for twice the initial sleep period (N).

In this way (the next sleep period is set to twice the previous sleep period), the sleep period continues to increase. Then, when the last sleep period (N2) is reached, the terminal repeatedly uses the last sleep period (N2) as the next sleep period. In this case, the final sleep window (N2) is set as follows through the parameters in the MOB-SLP-RSP shown in FIG.                         

Last sleep period (N2) = final sleep window base * 2 ^{final window exponent}

On the other hand, if there is a downlink traffic directed to itself through the MOB-TRF-IND message during the listening period (during L'frame) (Positive indication), the MSS ends the sleep mode and the downlink traffic from the normal mode. Receive

As described above, conventionally, two methods are supported to distinguish the terminals in the sleep mode or to direct the operation of the terminals. The first method is a method of using a sleep ID bitmap based on a sleep ID (SLPID), and the second method is a method of directly using a connection ID of a terminal.

However, when instructing the behavior of the terminal using the sleep ID bitmap based on the sleep ID (SLPID) as in the prior art, the length of the message (eg, MOB-TRF-IND) message transmitted to the terminal in the sleep state becomes longer. There are disadvantages.

In addition, when the connection ID of the terminal is used, the conventional base station can only indicate terminals that need to end the sleep mode, but has a disadvantage in that it cannot indicate periodic ranging. In particular, when the basic connection ID of the terminal is used to indicate the operations of the terminal, the base station uses only the lower 12 bits except the upper 4 bits from the basic connection ID of 16 bits.

Therefore, if the lower 12 bits other than the upper 4 bits in the basic connection ID are the same, the base station cannot accurately indicate the operation of the terminal using the connection ID. In addition, although there is a 10-bit sleep ID used in the sleep mode, the conventional base station uses a 12-bit connection ID, there is a disadvantage that the length of the message to deliver to the terminal in the sleep state.

Accordingly, an object of the present invention is to provide a method that can explicitly instruct the operation of the sleep mode terminal using the sleep ID.

Another object of the present invention is to provide a method for reducing the length of a message periodically transmitted to a terminal in a sleep mode.

In order to achieve the above object, the present invention explicitly indicates the end of the sleep mode and / or periodic ranging to the terminal in the sleep state using the sleep ID.

Preferably, the sleep ID is transmitted via a traffic notification (MOB-TRF-IND) message.

The present invention is implemented in a broadband wireless access system. However, the present invention can also be applied to a wireless communication system operating according to other standards. Hereinafter, preferred embodiments of the present invention will be described in detail.

The present invention provides a method for explicitly transmitting the operation of the terminal in the sleep mode using the sleep ID (SLPID). To this end, the present invention provides a modified traffic notification (MOB-TRF-IND) message.

4 is an example of a traffic notification (MOB-TRF-IND) message according to the present invention.                     

Referring to FIG. 4, a traffic notification (MOB-TRF-IND) message according to the present invention includes a Num-SLPID field, an SLPID field, and a ranging frame offset field.

The 7-bit Num-SLPID field represents the number of sleep IDs (SLPID), and the 10-bit SLPID represents the operation of the terminal in the sleep mode. That is, the SLPID has two bits assigned to one terminal MSS0. For example, a bit value 00 represents a case in which there is no periodic ranging and downlink (DL) traffic, and a bit value 01 represents no periodic ranging. In addition, bit value 10 represents a case in which there is a periodic ranging but no DL traffic, and bit value 11 represents a case in which both periodic ranging and DL traffic exist.

The ranging frame offset field indicates a frame offset when the bit value of the SLPID is set to 10 or 11.

Therefore, when using such a method, the length of a traffic notification (MOB-TRF-IND) message delivered to terminals is reduced in two aspects.

1) In case of instructing terminals to exit sleep mode, the base station can save 10 bits of length by using 10 bits of sleep ID (SLPID) instead of 12 bits of short basic CID SLPID. have.

2) In case of indicating periodic ranging, the base station can reduce the length of a considerable amount of MOB-TRF-IND message by using the sleep ID instead of the sleep bitmap.

For example, in order to quantitatively indicate the effect of the second method, consider a case in which the base station instructs periodic ranging to a terminal having SLPID = 1023. In this case, when using the sleep bitmap as in the related art, an SLPID bitmap having a length of 2 * 1024 = 2048 bits = 256 bytes is required to indicate the behavior of the UE having 1023. Thus, as shown in FIG. 5, the total length of the MOB-TRF-IND message is 8 + 1 + 8 + 2048 + 8 + 10 + 5 (padding) = 2088bits = 261 bytes.

However, as shown in FIG. 4, when the operation information of the UE is directly informed using the SLPID as shown in FIG. 4, the total length of the MOB-TRF-IND message is 8 + 1 + 7 + 10 + 2 + 8 + 10 + 2. (padding) = 6 bytes

As described above, the present invention can greatly reduce the length of the traffic notification message by instructing the sleep mode terminal operation (sleep mode termination or periodic ranging) using the sleep ID. In particular, the present invention may indicate all operations indicated by the sleep ID bitmap even when using the sleep ID.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (6)

In a broadband wireless access system, The base station instructs the operation of the terminal to indicate the operation of the terminal to end the sleep mode using the sleep ID. The method of claim 1, wherein the sleep ID is Method of operation of the terminal, characterized in that delivered to the terminal via a traffic notification message. In a broadband wireless access system, The base station informs the terminal in the sleep mode using the sleep ID to perform periodic ranging, characterized in that the terminal. The method of claim 3, wherein the sleep ID is Method of operation of the terminal, characterized in that delivered to the terminal via a traffic notification message. In a broadband wireless access system, The base station instructs the terminal in the sleep state using the sleep ID to indicate the end of the sleep mode and periodic ranging, characterized in that the operation of the terminal. The method of claim 5, wherein the sleep ID is Method of operation of the terminal, characterized in that delivered to the terminal via a traffic notification message.

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