KR20120079820A - Method for assigning terminal identifier, base station and terminal in mobile communication system - Google Patents

Abstract

PURPOSE: A terminal identifier allocating method, a base station supporting the same, and a terminal in a mobile communication system are provided to allocate terminal identifiers about terminals while maintaining backward compatibility. CONSTITUTION: A processor(1210) generates an error control bit sequence for a control message. The control message includes the resource allocation information. The processor masks the error control bit sequence to a first mask. The processor masks the error control bit sequence to a second mask. The processor transmits the control message to the terminal.

Description

Method of allocating terminal identifier in mobile communication system, base station and terminal supporting it {METHOD FOR ASSIGNING TERMINAL IDENTIFIER, BASE STATION AND TERMINAL IN MOBILE COMMUNICATION SYSTEM}

The present invention relates to a mobile communication system. More specifically, the present invention relates to a terminal identifier allocation method in a broadband mobile communication system.

In a broadband mobile communication system, a base station allocates an identifier for each terminal to manage a terminal accessing the base station. The terminal identifier assigned to each terminal should be a unique value within the base station. The terminal identifier is assigned when the terminal attempts to access the network, and is used to identify the terminal when the base station wants to control the state of the accessing terminal or allocates resources to the terminal.

Currently, in a broadband mobile communication system (eg IEEE 802.16m), a 12-bit STID (Station Identification) or TSTID (Temporary STID) is used as a terminal identifier. The STID is transmitted in a medium access control (MAC) control message and may be used to identify a specific terminal. In addition, the STID may be included in a MAP message for allocating an uplink radio resource or a downlink radio resource and used to indicate a target terminal of the allocated radio resource. Therefore, the base station can identify up to 4096 terminals using a 12-bit STID.

However, due to changes in various communication environments, the number of terminal identifiers managed by a base station is required to be further increased. For example, as user demands for ubiquitous networks increase, market demand for realizing machine-to-machine communication (M2M) using a broadband mobile communication system increases. Every device or device in a system that supports inter-object communication must be controlled by a base station. At this time, the number of devices or devices to be controlled by the base station for M2M communication may be much larger than the number of terminal identifiers that can be allocated by the base station. In this case, the base station may not be able to control a sufficient number of devices or devices with only 12 bits of STID.

In addition, when a terminal according to a protocol defined in an existing broadband mobile communication system and a terminal according to a newly defined protocol are mixed to support M2M communication, the base station must simultaneously support two terminals.

Therefore, in order to support the M2M communication, the base station should also consider the backward compatibility for the terminal according to the existing protocol along with a scheme for identifying and controlling a larger number of terminals.

An object of the present invention is to provide a terminal identifier allocation method for M2M communication in a broadband mobile communication system.

In a mobile communication system according to an aspect of the present invention, a method for transmitting a signal to a terminal by a base station includes allocating a terminal identifier including a first region and a second region to the terminal, and a control message including resource allocation information. Generating an error control bit sequence, masking the error control bit sequence with a first predefined mask, masking the error control bit sequence masked with the first mask with a second predefined mask, and And transmitting the control message including the error control bit sequence masked with the second mask to the terminal, wherein the first mask and the second mask each include a masking prefix field, a type indicator field, and a terminal identification field. The terminal identification field of the first mask includes a first area of the terminal identifier. And, terminal identification field of the second mask is set to a second region of the terminal identifier.

A base station for use in a mobile communication system according to an aspect of the present invention includes a radio frequency (RF) unit; And a processor, wherein the processor allocates a terminal identifier including a first region and a second region to a terminal, generates an error control bit sequence for a control message including resource allocation information, and generates the error control bit sequence. Masking with a predefined first mask, masking the error control bit sequence masked with the first mask with a second predefined mask, and including the error control bit sequence masked with the second mask. Is transmitted to the terminal, wherein the first mask and the second mask each include a masking prefix field, a type indicator field, and a terminal identification field, and the terminal identification field of the first mask is a first one of the terminal identifiers. And a terminal identification field of the second mask includes a second region of the terminal identifier. The lock is set.

In a method for receiving a signal from a base station by a terminal in a mobile communication system according to an aspect of the present invention, the method comprising: receiving a terminal identifier including a first area and a second area from a base station, resource allocation information and error control bits from the base station; Receiving a control message comprising a sequence, and sequentially decoding the control message using a predefined first mask and a predefined second mask, wherein the first mask and the second mask are decoded. Respectively include a masking prefix field, a type indicator field, and a terminal identification field, the terminal identification field of the first mask includes a first region of the terminal identifier, and the terminal identification field of the second mask is one of the terminal identifiers It is set to include a second area.

A terminal for use in a mobile communication system according to an aspect of the present invention includes a radio frequency (RF) unit and a processor, the processor obtaining a terminal identifier including a first area and a second area from a base station. Is allocated to receive a control message including resource allocation information and an error control bit sequence from the base station, and sequentially decode the control message using a predefined first mask and a predefined second mask, Each of the first mask and the second mask includes a masking prefix field, a type indicator field, and a terminal identification field, the terminal identification field of the first mask includes a first region of the terminal identifier, and the second mask The terminal identification field of is set to include a second area of the terminal identifier.

According to a feature of the present invention, terminal identifiers can be assigned to a greater number of terminals while maintaining backward compatibility.

1 is an example of a control message (eg, MAP message) including resource allocation information for a terminal.
2 is an example of a CRC mask.
3 illustrates a structure of a terminal identifier for identifying a terminal according to an embodiment of the present invention.
4 is a diagram illustrating a primary CRC mask and a secondary CRC mask according to an embodiment of the present invention.
5 is a flowchart illustrating a method for transmitting, by a base station, a MAP message, which is a control message including resource allocation information for a terminal, according to an embodiment of the present invention.
6 shows a CRC masking method of a base station.
7 is a flowchart illustrating a method for acquiring allocated resource information through a MAP message according to an embodiment of the present invention.
8 illustrates a base station and a terminal that can be applied to an embodiment of the present invention.

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.

Throughout the specification, a mobile station (MS) is a terminal, a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS), an access terminal (access) It may refer to a terminal (AT), a user equipment (UE), or the like, and may include all or some functions of the terminal, MT, SS, PSS, AT, UE, and the like.

In addition, the base station (BS) is a node B (eB), an evolved node B (eNodeB), an access point (AP), a radio access station (radio access station (RAS)), a base transceiver station may refer to a base transceiver station (BTS), a mobile multihop relay (MMR) -BS, or the like, and may include all or a part of functions of a NodeB, an eNodeB, an AP, a RAS, a BTS, an MMR-BS, and the like.

Hereinafter, a method of allocating a terminal identifier in a broadband mobile communication system according to an embodiment of the present invention will be described with reference to the accompanying drawings.

1 is an example of a control message (eg, MAP message) including resource allocation information for a terminal. In the present specification, the MAP message may be mixed with MAP, MAP Information Element (IE), Advanced MAP (A-MAP), A-MAP message, and A-MAP IE.

Referring to FIG. 1, the MAP message 100 includes an error control bit sequence (eg, CRC (Cyclic Redundancy) generated by bitwise computing MAP main body 110 including resource allocation information and information included in the MAP main body 110. 120). After the base station generates the MAP body 110, the base station generates a CRC using the contents of the MAP body 110. The base station generates a new CRC by performing an XOR (Exclusive OR) operation on the generated CRC with a predefined CRC mask. The base station adds the generated new CRC 120 to the MAP body 110, and transmits it to the terminal. Here, the CRC mask may include information about a target terminal of the MAP message 100 (eg, a terminal identifier) and type information (eg, broadcast and multicast) of the MAP message 100. A detailed description of the CRC mask is illustrated in detail in FIG. 2.

The terminal receiving the MAP message 100 generates a CRC by using the MAP body 110. The terminal then performs an XOR operation on the generated CRC with a known CRC mask and compares the result with the CRC 120 included in the MAP message 100. Here, the CRC mask may include terminal identification information or MAP message type information as described above. Since the CRC mask includes the terminal identification information, if the result of the comparison is equal to the CRC 120 received by the terminal and the terminal, the terminal determines that the received MAP message 100 is a MAP message for itself. . As a result, the UE may acquire resource allocation information included in the MAP message 100. On the other hand, if the CRC 120 received by the terminal is not the same as the result calculated by the terminal, the terminal is a MAP message for the other terminal or the received MAP message 100 is an error occurred Judge and discard.

2 is an example of a CRC mask.

Referring to FIG. 2, the CRC mask 200 may include a 1-bit masking prefix field 210, a 3-bit type indicator field 220, and a 12-bit STID field. 230). As such, the total length of the CRC mask 200 is 16 bits like the CRC. The CRC mask 200 includes a STID which is a terminal identifier.

Table 1 shows the configuration of the CRC mask.

Masking Prefix (1bit MSB) Remaining 15bit LSBs 0b0 Type Indicator (3bit) Masking Code (12bit) 0b000 0-4095
(12bit STID or TSTID) Unicast transfer 0b001 0 Broadcast assignment A-MAP IE transmission (Broadcast or ranging channel assignment) One BR-ACK A-MAP IE Transmission 2 ~ 128
(group ID) Send GRA A-MAP IE Others Reserved 0b010 Others reserved 4095 Broadcast assignment A-MAP IE transmission (Multicast assignment) 0b011 ~ 0b111 reserved 0b1 15 bit RA-ID

A-MAP IE: Advanced-MAP Information Element

BR-ACK A-MAP IE: Bandwidth Request-Acknowledgement A-MAP IE

GRA A-MAP IE: Group Resource Allocation A-MAP IE

As shown in Table 1, the most significant 1 bit (MSB) is a masking prefix 210, and the remaining 15 bits (LSB) are composed of a 3-bit type indicator 220 and a 12-bit STID 230. Of the type indicators, the remaining areas 0b011 to 0b111 except for 0b000 to 0b010 for which use is already determined are not used.

In one embodiment of the present invention, a terminal is identified by using an extended STID (eSTID) of 24 bits.

In the present specification, for convenience of description, a terminal according to a protocol defined in an existing broadband mobile communication system (hereinafter referred to as a legacy system) and identified by a 12-bit STID is referred to as a legacy terminal, and improved communication (eg, M2M communication). In accordance with the newly defined protocol to support the terminal is called an improved terminal (eg, M2M terminal). In the present specification, an M2M terminal is used as an example of an improved terminal for better understanding of the present invention, but the terminal is not limited to the M2M terminal in one embodiment of the present invention.

3 illustrates a structure of a terminal identifier for identifying a terminal according to an embodiment of the present invention.

Referring to FIG. 3, the 24-bit terminal identifier eSTID 300 includes an upper 12 bits (12 MSBs) 310 and a lower 12 bits (12 LSBs) 320.

Meanwhile, the upper 12 bits 310 and the lower 12 bits 320 of the eSTID 300 may be used to configure a CRC mask of the MAP including resource allocation information for the terminal. For example, the CRC mask may be set as a primary CRC mask including the lower 12 bits of the eSTID and a secondary CRC mask including the upper 12 bits of the eSTID.

4 is a diagram illustrating a primary CRC mask and a secondary CRC mask according to an embodiment of the present invention. Referring to FIG. 4, the primary CRC mask 400 includes a 1-bit mask prefix 402, a 3-bit type indicator 404, and a lower 12-bit 406 of the eSTID 300. The secondary CRC mask 410 includes a 1-bit mask prefix 410, a 3-bit type indicator 414, and an upper 12 bit 416 of the eSTID 300.

In this case, the areas 0b011 to 0b111 that are not used in the legacy system among the 3-bit type indicators 404 and 410 may be used to indicate that the target terminal of the MAP message is not a legacy terminal but an M2M terminal. The type indicator 404 of the primary CRC mask 400 and the type indicator 414 of the secondary CRC mask 410 may be set to different values.

5 is a flowchart illustrating a method for transmitting, by a base station, a MAP message, which is a control message including resource allocation information for a terminal, according to an embodiment of the present invention.

Referring to FIG. 5, when a terminal accesses a network, the base station allocates a terminal identifier including a 24-bit eSTID to the corresponding terminal (S500). Here, the terminal identifier may be used when the terminal accesses or disconnects from the system, when the base station controls the state of the terminal, when the base station transmits resource allocation information to the terminal. The 24-bit eSTID may consist of upper 12 bits (MSBs) and lower 12 bits (LSBs).

The base station transmits the allocated terminal identifier to the terminal through a MAC message (S510).

The base station generates a MAP body including resource allocation information (S520), and generates a CRC using the MAP body (S530). The base station calculates the generated CRC with the first logical CRC and the first logical exclusive sum (Exclusive OR, XOR) (S540), and then performs a second XOR with the second CRC mask (S550). 6 shows a CRC masking method of a base station. As shown in FIG. 6, the base station performs an XOR operation on the CRC generated using the MAP main body with the primary CRC mask and then performs an XOR operation on the secondary CRC mask. Here, the primary CRC mask may be configured to include the lower 12 bits of the 24-bit terminal identifier, and the secondary CRC mask may be configured to include the upper 12 bits of the 24-bit terminal identifier. Meanwhile, the type indicator of the primary CRC mask or the secondary CRC mask may be used to indicate that the target terminal of the MAP message is not a legacy terminal but an M2M terminal.

The base station adds the calculation result to the end of the MAP main body as a CRC to generate a MAP message (S560), and transmits the generated MAP message to the terminal (S570).

7 is a flowchart illustrating a method for acquiring allocated resource information through a MAP message according to an embodiment of the present invention.

Referring to FIG. 7, the terminal is assigned a terminal identifier from the base station (S700). The terminal identifier may be assigned through a MAC message when the terminal enters the network. Here, the terminal identifier may include a 24-bit eSTID. The 24-bit eSTID may consist of upper 12 bits (MSBs) and lower 12 bits (LSBs).

In addition, the terminal receives a control message including resource allocation information from the base station (S710). The control message including the resource allocation information may be a MAP body including the resource allocation information and a MAP message including the CRC. The CRC may be a result obtained by performing an XOR operation on a CRC generated by bit-operating the MAP body with a predefined CRC mask.

The terminal calculates a CRC using the MAP main body (S720), performs an XOR operation on the calculated CRC with a predefined primary CRC mask, and then performs an XOR operation on the operation result with a predefined secondary CRC mask (S730). In step S700, if the terminal identifier assigned by the terminal from the base station is a 24-bit eSTID, the terminal allocates the terminal identifier in consideration of the M2M terminal, and removes two CRC masks in order to decode the MAP message. It can be seen that this is necessary. Here, the primary CRC mask may be configured to include the lower 12 bits (LBSs) of the 24-bit eSTID, and the secondary CRC mask may be configured to include the upper 12 bits (MBSs) of the 24-bit eSTID.

The terminal compares the new CRC generated as a result of the XOR operation two times with the CRC included in the MAP message (S740).

If the new CRC and the CRC included in the MAP message are different, the received MAP message is determined to be a MAP message or an error for another UE and discarded (S750).

On the other hand, if the new CRC and the CRC included in the MAP message are the same, it is determined that the received MAP message is a MAP message for itself, and the resource allocation information is obtained by analyzing the MAP body (S760).

Meanwhile, by configuring the type indicator included in the primary CRC mask and the type indicator included in the secondary CRC mask differently from the legacy system, the MAP message may be properly decoded only to the corresponding M2M terminal. For example, the value of the type indicator of the primary CRC mask is set to a value indicating that it is a CRC mask including lower 12 bits (LSBs) of the 24-bit terminal identifier, and the value of the type indicator of the secondary CRC mask is 24 bits. It may be set to a value indicating that the CRC mask including the upper 12 bits (MSBs) of the terminal identifier of.

In addition, the type indicator for supporting and controlling the group operation of the M2M terminal may be set separately. For example, the same upper 12 bits (MSBs) may be allocated to M2M terminals belonging to the same group, and a type indicator value indicating the same may be separately set.

Table 2 shows the type indicators of the primary CRC mask and the secondary CRC mask according to an embodiment of the present invention.

Masking Prefix (1bit MSB) Remaining 15bit LSBs 0b0 Type Indicator (3bit) Masking Code (12bit) 0b000 0-4095
(12bit STID or TSTID) Unicast transfer 0b001
0 Broadcast assignment A-MAP IE transmission (Broadcast or ranging channel assignment) One BR-ACK A-MAP IE Transmission 2 ~ 128
(group ID) Send GRA A-MAP IE others Reserved 0b010
others reserved 4095 Broadcast assignment A-MAP IE transmission (Multicast assignment) 0b011
0-4095
(12 LSBs of eSTID) Unicast transfer 0b100
0-4095
(12 LSBs of eSTID) Unicast transfer 0b101
0-4095
(12 MSBs of eSTID) Unicast transfer 0b110
0-4095
(12 MSBs of eSTID) Unicast transfer 0b111
0-4095
(12 MSBs of eSTID) Multicast transmission
(Group control) 0b1 15 bit RA-ID

As described above, the value of the type indicator for the primary CRC mask and the value of the type indicator for the secondary CRC mask may be set differently in unicast.

The type indicator supporting group operation of the M2M terminal may also be separately set.

The type indicator for the primary CRC mask, the type indicator for the secondary CRC mask, and the type indicator for indicating the group operation may be freely set from values except for the type indicator regions 1 and 2 used in the legacy system.

8 illustrates a base station and a terminal that can be applied to an embodiment of the present invention.

Referring to FIG. 8, the mobile communication system includes a base station (BS) 1200 and a terminal (UE) 1300. The base station 1200 includes a processor 1210, a memory 1220, and a radio frequency (RF) unit 1230. The processor 1210 may be configured to implement the procedures and / or methods proposed by the present invention. The memory 1220 is connected to the processor 1210 and stores various information related to the operation of the processor 1210. The RF unit 1230 is connected with the processor 1210 and transmits and / or receives a radio signal. The terminal 1300 includes a processor 1310, a memory 1320, and an RF unit 1330. The processor 1310 may be configured to implement the procedures and / or methods proposed by the present invention. The memory 1320 is connected to the processor 1310 and stores various information related to the operation of the processor 1310. The RF unit 1330 is connected with the processor 1310 and transmits and / or receives a radio signal. The base station 1200 and / or the terminal 1300 may have a single antenna or multiple antennas.

The embodiments of the present invention described above are not implemented only by the apparatus and method, but may be implemented through a program for realizing the function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

Claims (13)

In the method of transmitting a signal to a terminal by a base station in a mobile communication system,
Allocating a terminal identifier including a first region and a second region to the terminal;
Generating an error control bit sequence for a control message comprising resource allocation information,
Masking the error control bit sequence with a first predefined mask;
Masking the error control bit sequence masked with the first mask with a second predefined mask; and
Transmitting the control message including the error control bit sequence masked with the second mask to the terminal,
Each of the first mask and the second mask includes a masking prefix field, a type indicator field, and a terminal identification field, the terminal identification field of the first mask includes a first region of the terminal identifier, and the second mask The terminal identification field of the terminal identifier is set to include a second area of the terminal identifier. The method of claim 1,
If the terminal is a first type terminal, the terminal is identified using the first region and the second region,
If the terminal is a second type terminal, the terminal is identified using the first region. The method of claim 2,
The value of the type indicator field of the first mask or the value of the type indicator field of the second mask is set to indicate that the terminal is the first type terminal. The method of claim 2,
When the terminal is the first type terminal, a value of a type indicator field of the first mask and a value of a type indicator field of the second mask are set differently. The method of claim 1,
The value of the type indicator field of the first mask or the value of the type indicator field of the second mask is set to a value indicating that the multicast transmission for group control of the machine to machine (M2M) terminal. The method of claim 1,
And the first region and the second region each comprise 12 bits. A base station for use in a mobile communication system,
A radio frequency (RF) unit; And
Includes a processor,
The processor allocates a terminal identifier including a first region and a second region to a terminal, generates an error control bit sequence for a control message including resource allocation information, and defines the error control bit sequence in a first predefined manner. Mask with a mask, mask the error control bit sequence masked with the first mask with a second predefined mask, and send the control message including the error control bit sequence masked with the second mask to the terminal. Wherein the first mask and the second mask each include a masking prefix field, a type indicator field, and a terminal identification field, the terminal identification field of the first mask includes a first region of the terminal identifier, The base station identification field of the second mask is set to include a second area of the terminal identifier. In a mobile communication system, a terminal receives a signal from a base station,
Receiving a terminal identifier including a first area and a second area from a base station;
Receiving a control message including resource allocation information and an error control bit sequence from the base station, and
Decoding the control message sequentially using a predefined first mask and a predefined second mask,
Each of the first mask and the second mask includes a masking prefix field, a type indicator field, and a terminal identification field, the terminal identification field of the first mask includes a first region of the terminal identifier, and the second mask The terminal identification field of the terminal identifier is set to include a second area of the terminal identifier. The method of claim 8,
If the terminal is a first type terminal, the terminal is identified using the first region and the second region,
If the terminal is a second type terminal, the terminal is identified using the first region. The method of claim 8,
The error control bit sequence is a cyclic redundancy check (CRC). The method of claim 10,
The decoding step
Generating a CRC by calculating a main body of the control message;
Performing an exclusive OR (XOR) operation on the CRC with the first mask;
Performing an XOR operation with the second mask on the result of the calculation with the first mask, and
Comparing the result of the operation with the second mask with a CRC included in the control message
≪ / RTI > The method of claim 11,
Obtaining resource allocation information from the control message if a result of the calculation with the second mask is the same as a CRC included in the control message. In the terminal for use in a mobile communication system,
A radio frequency (RF) unit, and
Includes a processor,
The processor receives a terminal identifier including a first area and a second area from a base station, receives a control message including resource allocation information and an error control bit sequence from the base station, and includes a predefined first mask and a predefined signal. And decode the control message by sequentially using the second mask, wherein the first mask and the second mask each include a masking prefix field, a type indicator field, and a terminal identification field, and the terminal of the first mask. The identification field includes a first area of the terminal identifier, and the terminal identification field of the second mask is set to include a second area of the terminal identifier.

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