JP5806668B2 - Method for updating base station system information of relay station in broadband wireless access system - Google Patents

Description

  The present invention relates to a broadband wireless access system, and more particularly, to a method for efficiently updating system information of a base station at a relay station and an apparatus for performing the method.

  In a next-generation wireless communication system, a relay station (RS) is expected to be widely used. The concept of the relay station (RS) will be briefly described as follows.

  IEEE of 2006 (Institute of Electrical and Electronics Engineers, American Institute of Electrical and Electronics Engineers) 802.16 provides mobility of subscriber terminals and IEEE 802.16-2004, which is a standard for fixed subscriber terminals After the publication of IEEE 802.16e-2005, which is a standard for communication, a new standardization project called multi-hop relay is currently underway.

  This project, which is in charge of task group j (IEEE 802.16j) within IEEE 802.16, was held for the second time in July 2006 since the first official meeting in May 2006. At the meeting, full-scale discussions began on the usage model, related terms (Terminology), and technical requirements (Technical Requirements). Hereinafter, the IEEE 802.16 task group j is abbreviated as “802.16j”.

  The relay station concept described below can be used as substantially the same concept for the relay station considered in the 3GPP LTE-A system. In addition, a relay station performing the same or similar function in various other wireless connection systems can be used as a concept similar to the relay station described in the present invention.

  The PAR (Project Authorization Request) of 802.16j has two purposes as standardization work that will be advanced in the future: Coverage Extension and Performance Enhancement (Throughput Enhancement).

  The relay stations can be roughly classified into two types, and there are relay stations in a transparent (transparent) and non-transparent (non-transparent) form. In the transparent relay station, all operations and functions exist in the relay station, and the relay station manages the terminal. On the other hand, the opaque relay station plays a role of relaying all operations and functions between the macro base station and the terminal via the macro base station.

  From the standpoint of the terminal, the transparent relay station and the opaque relay station are handled as one macro base station without being distinguished, and there is no change in operation, but the terminal may have a function of distinguishing between the relay station and the macro base station.

  A network including a relay station can include a base station (BS), a relay station (RS), and a terminal (MS). The terminal can receive a radio signal via the relay station even outside the cell area of the base station. In addition, a high-quality route having a high-level adaptive modulation and coding (AMC) scheme can be set for a terminal in the cell area of the base station via a relay station. Therefore, the user can obtain the effect of increasing the capacity of the entire system using the same radio resource.

  The standard created by the 802.16j project has certain requirements. For example, a mobile terminal implemented based on the existing 802.16-2004 and 802.16e-2005 standards must be able to communicate with a relay station without adding any functions. Therefore, in the existing system, the application range of the relay station can be limited by adding a partial function for controlling the relay station to the relay station itself and the existing base station. The standard for relay stations is expected to become the core of standardization in the future.

  The relay station can be regarded as a kind of subscriber terminal that operates in the physical layer and the medium access control layer, and is mainly controlled by the base station, but if necessary, the relay station also has a predetermined control function. Can do. The utilization model under discussion includes not only fixed relay stations but also various types of relay stations such as mobile relay stations for temporary service provision to specific areas and relay stations that can be mounted on cars and subways. Has been.

  Typical technical issues to be discussed in the future can be summarized as follows.

  1. A procedure for a base station to identify relay stations existing in its own area, and to acquire and maintain information on the topology with them.

  2. Definition of a physical transmission frame structure between a mobile terminal and a relay station, which is compatible with the existing IEEE 802.16 system (backward compatibility).

  3. A signaling procedure for providing mobility between relay stations or between a relay station and a base station.

  4). A procedure for entering the base station of the relay station and a procedure for entering the mobile terminal via the relay station.

  The relay station exchanges data with the terminal and exchanges data with the base station. However, since the relay station and the base station are synchronized with each other, the system information is broadcast at the same time. Therefore, since the relay station broadcasts its own system information in the transmission mode when the base station broadcasts the system information, the relay station cannot receive the base station system information. Further, as described above, since the relay station has a section for receiving data from the base station, a method for notifying the terminal and the lower relay station of such a section is also required.

  The present invention has been devised in order to solve the above-mentioned general technical problems, and an object of the present invention is to enable the relay station to efficiently acquire the changed system information of the base station. It is to provide a method and an apparatus therefor.

  Another object of the present invention is to provide a method and apparatus for efficiently transmitting system information additionally required for a relay station to terminals and lower relay stations.

  The technical problem to be achieved by the present invention is not limited to the technical problem mentioned above, and other technical problems that are not mentioned are based on the following description and are based on ordinary knowledge in the technical field to which the present invention belongs. It will be clearly understood by those who have

  In order to solve the problems of the general technique as described above, the base station (ABS) system information updating method of the relay station (ARS) in the broadband wireless access system according to an embodiment of the present invention is the base station system. Receiving a first message including information change information from the base station; transmitting a second message for confirming reception of the first message to the base station; and applying the change information. , Can be included.

  At this time, the system information includes a first subpacket, a second subpacket, and a third subpacket, and the change information is a bit that indicates whether or not update information of each subpacket is included by 1 bit. A map field and update information of a subpacket corresponding to a bit set to '1' in the bitmap field may be included.

  In addition, the update information of each subpacket includes a number action field that indicates a time point when the update information of the corresponding subpacket is applied in units of superframes, and the step of applying the change information is performed for each subpacket. It is desirable that this is performed at the time indicated by the number action field.

  In order to solve the problems of the general technique as described above, in a broadband wireless access system according to another embodiment of the present invention, a method in which a base station (ABS) informs a relay station of a change in system information includes: Transmitting a first message including change information of station system information to the relay station and receiving a second message for confirming reception of the first message from the relay station.

  At this time, the system information includes a first subpacket, a second subpacket, and a third subpacket, and the change information is a bit that indicates whether or not update information of each subpacket is included by 1 bit. A sub-packet update information corresponding to a bit set to '1' in the bitmap field, and the sub-packet update information is applied to the sub-packet update information. A number action field indicating the time point in units of superframes may be included.

  The method may further include retransmitting the first message to the relay station when the second message is not received from the relay station.

  In order to solve the problems of the general technique as described above, a relay station (ARS) operating in a broadband wireless access system according to still another embodiment of the present invention includes a processor and an external device controlled by the processor. And a radio communication (RF) module for transmitting and receiving radio signals. Here, the processor acquires change information of the base station system information through a first message received from a base station (ABS), controls the wireless communication module, and confirms reception of the first message. The second message is transmitted to the base station, and the acquired change information is applied.

  At this time, the system information includes a first subpacket, a second subpacket, and a third subpacket, and the change information is a bit that indicates whether or not update information of each subpacket is included by 1 bit. A map field and update information of a subpacket corresponding to a bit set to '1' in the bitmap field may be included.

  In addition, the update information of each subpacket includes a number action field indicating the time point when the update information of the corresponding subpacket is applied in superframe units, and the step of applying the change information includes: Each subpacket can be performed at the time indicated by the number action field.

  In each of the above embodiments, the first message is preferably transmitted from the base station by an event-triggered method every time the system information is changed.

  In each of the above-described embodiments, it is preferable that the first message is a relay station essential system information (RS_ESI) message and the second message is a message acknowledgment (AAI_MSG-ACK) message.

  Each embodiment of the present invention has the following effects.

  First, the relay station can efficiently acquire the changed system information of the base station through the essential system information message, and the base station can apply it at a desired time.

Second, system information such as area information and hop information additionally required for the relay station can be efficiently transmitted to the terminal.
For example, the present invention provides the following items.
(Item 1)
A base station (ABS) system information update method for a relay station (ARS) in a broadband wireless access system, comprising:
Receiving a first message including change information of the base station system information from the base station;
Transmitting a second message for confirming reception of the first message to the base station;
Applying the change information. A system information update method.
(Item 2)
The system information includes a first subpacket, a second subpacket, and a third subpacket,
The change information is
The change count field that indicates the change count of the system information, the bitmap field that indicates whether or not the update information of each subpacket is included by 1 bit, and the bitmap field are set to '1' The system information update method according to item 1, further comprising: update information of a subpacket corresponding to a bit.
(Item 3)
The update information of each subpacket is:
Including a superframe number action field that indicates the time point when the update information of the corresponding subpacket is applied in superframe units;
Applying the change information comprises:
3. The system information updating method according to item 2, wherein the system information updating method is performed at a time point indicated by the number action field for each subpacket.
(Item 4)
The first message is:
2. The system information update method according to item 1, wherein the system information is transmitted by an event-triggered method every time the system information is changed.
(Item 5)
The first message is a relay station essential system information (RS_ESI) message,
The system information update method according to item 1, wherein the second message is a message acknowledgment (AAI_MSG-ACK) message.
(Item 6)
A method in which a base station (ABS) informs a relay station of a change in system information in a broadband wireless access system,
Transmitting a first message including change information of the base station system information to the relay station;
Receiving a second message for confirming reception of the first message from the relay station.
(Item 7)
The system information includes a first subpacket, a second subpacket, and a third subpacket,
The change information is
The change count field that indicates the change count of the system information, the bitmap field that indicates whether or not the update information of each subpacket is included by 1 bit, and the bitmap field are set to '1' Update information of the subpacket corresponding to the bit, and
The update information of each subpacket is:
Item 7. The system information update method according to Item 6, including a superframe number action field that indicates a time point at which update information of the corresponding subpacket is applied in units of superframes.
(Item 8)
The first message is:
7. The system information updating method according to item 6, wherein the system information is transmitted by an event-triggered method every time the system information is changed.
(Item 9)
If the second message is not received from the relay station,
7. The system information update method according to item 6, further comprising the step of retransmitting the first message to the relay station.
(Item 10)
The first message is a relay station essential system information (RS_ESI) message,
The system information update method according to item 6, wherein the second message is a message acknowledgment (AAI_MSG-ACK) message.
(Item 11)
In a relay station (ARS) operating in a broadband wireless access system,
A processor;
A wireless communication (RF) module for transmitting and receiving wireless signals to and from the outside under the control of the processor,
The processor is
The change information of the base station system information is obtained through a first message received from a base station (ABS), the wireless communication module is controlled, and a second message for confirming reception of the first message is the base message A relay station, wherein the relay station is transmitted to a station, and is controlled so that the acquired change information is applied.
(Item 12)
The system information includes a first subpacket, a second subpacket, and a third subpacket,
The change information is
The change count field that indicates the change count of the system information, the bitmap field that indicates whether or not the update information of each subpacket is included by 1 bit, and the bitmap field are set to '1' 12. The relay station according to item 11, including update information of a subpacket corresponding to the bit.
(Item 13)
The update information of each subpacket is:
A super frame number action (Number Action) field indicating the time point when the update information of the corresponding subpacket is applied in units of super frames;
Applying the change information comprises:
13. The relay station according to item 12, wherein the relay station is performed at a time point indicated by the number action field for each subpacket.
(Item 14)
The first message is:
12. The relay station according to item 11, wherein the relay station is transmitted from the base station by an event-triggered method every time the system information is changed.
(Item 15)
The first message is a relay station essential system information (RS_ESI) message,
12. The relay station according to item 11, wherein the second message is a message acknowledgment (AAI_MSG-ACK) message.

  The effects obtained by the present invention are not limited to the effects mentioned above, and other effects not mentioned are clearly understood by those having ordinary knowledge in the technical field to which the present invention belongs from the following description. It will be.

It is a figure which shows the frame structure of the relay station by the frequency division duplex (FDD) of a general IEEE 802.16m system, and a base station. It is a figure which shows each the frame structure of the relay station and base station by time division duplexing (TDD). It is a figure which shows an example of the form which notifies the area | region information of a relay station through the map area | region which concerns on one Example of this invention. It is a figure which shows the other example of the form which notifies the area | region information of a relay station through the map area | region which concerns on one Example of this invention. It is a figure which shows an example of the network arrangement | positioning form of a base station and its subordinate relay station. It is a figure which shows an example of the procedure in which the relay station which concerns on the other Example of this invention updates the system information of a base station. It is a figure which shows an example of the setting method of the relay station identifier and multicast identifier which concern on the other Example of this invention. It is a block diagram which shows an example of a transmission end and a receiving end structure as further another Example of this invention.

  The present invention relates to a wireless connection system. Hereinafter, each embodiment of the present invention discloses an efficient system information transmission / update method of a relay station.

  The following embodiments are obtained by combining constituent elements and features of the present invention in a predetermined form. Each component or feature can be considered optional unless otherwise explicitly stated. Each component or feature may be implemented in a form that is not combined with other components or features. Also, some embodiments and / or features may be combined to form an embodiment of the present invention. The order of operations described in the embodiments of the present invention can be changed. Some configurations or features of one embodiment may be included in other embodiments or may replace corresponding configurations or features of other embodiments.

  In the present specification, the embodiments of the present invention have been described centering on the data transmission / reception relationship between the base station and the terminal. Here, the base station has the meaning of a terminal node (terminal node) of the network that directly communicates with the terminal. The specific operations described in this document as being performed by the base station may be performed by an upper node of the base station in some cases.

  That is, various operations performed for communication with a terminal in a network including a large number of network nodes including a base station can be performed by the network node other than the base station or the base station. Is self-explanatory. Here, “base station (BS)” is replaced with terms such as fixed station, Node B, eNode B (eNB), access point (AP: Access Point), ABS (Advanced BS), and the like. Is possible.

  Also, 'terminal (Terminal)' may be replaced with a term such as UE (User Equipment), MS (Mobile Station), MSS (Mobile Subscriber Station), AMS (Advanced MS), or SS (Suscriber Station).

  Embodiments of the present invention can be implemented through various means. For example, the embodiments of the present invention may be implemented by hardware, firmware, software, or a combination thereof.

  In the case of implementation by hardware, the method according to an embodiment of the present invention may include one or more ASICs (application specific integrated circuits), DSPs (digital signal processor), DSPS (digital signal processing), DSPDs (digital signal processing). devices), FPGAs (field programmable gate arrays), processors, controllers, microcontrollers, microprocessors, and the like.

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

  Each embodiment of the present invention can be supported by a standard document disclosed in at least one of IEEE 802 system, 3GPP system, 3GPP LTE system, and 3GPP2 system which are wireless connection systems. That is, the above-described document can support a stage or a portion of the embodiments of the present invention that are not described in order to clarify the technical idea of the present invention. In addition, all the terms disclosed in this document can be explained by the above standard documents. In particular, each embodiment of the present invention can be supported by at least one of IEEE 802.16 system standard documents P802.16-2004, P802.16e-2005, P802.16Rev2 and IEEE P802.16m documents.

  The specific terms used in the following description are provided to assist the understanding of the present invention, and the use of such specific terms may take other forms without departing from the technical idea of the present invention. Can be replaced.

  In the broadband wireless access system including the relay station according to each embodiment of the present invention, the following assumptions are applied. In particular, each embodiment of the present invention assumes an opaque relay station.

  1. The relay station is synchronized with the macro base station.

  2. The terminal is synchronized with the macro base station to which the corresponding relay station belongs while receiving service from the relay station.

  3. In the case of a transparent relay station (Transparent RS), the medium connection control management message (MAC management message) is transmitted to the terminal only by the macro base station or transmitted to the terminal via the relay station.

  4). The relay station may have a function of calculating code division multiple access code signal measurement (CDMA code signal measurement) or channel state information measurement (CQI measurement) information for physical control.

  5. Scheduling may be configured in a centralized (distributed scheduling) mode or a distributed (moderated) scheduling mode.

  In each embodiment of the present invention, the relay station (ARS: Advanced Relay Station) is divided into an odd hop ARS (even hop ARS) and an even hop ARS (even hop ARS) according to the number of hops with the base station (ABS). Can be segmented. The odd hop ARS and the even hop ARS may have a hierarchical structure, and one network may include one or more odd hops ARS and one or more even hops ARS.

  The frame structure used in the relay station can be composed of a downlink and an uplink frame structure. At this time, the DL frame structure includes a DL access zone and a DL relay zone, and the UL frame structure includes an UL access zone and an uplink relay. A region (UL Relay Zone) may be included.

  At this time, if only one relay station exists between the base station and the terminal (one hop structure), the relay station (ARS) transmits data packets to the terminal (AMS) in the downlink connection area. The uplink connection area represents a section in which a terminal (AMS) transmits a data packet or the like to a corresponding relay station (ARS). Also, the relay station (ARS) can receive data packets from the base station (ABS) in the downlink relay area, and the relay station (ARS) transmits data packets to the base station (ABS) in the uplink relay area. be able to.

  The frame structure of the relay station in such a single hop structure is shown in FIG. 1 and FIG.

  FIG. 1 shows a frame structure of a relay station and a base station by frequency division duplex (FDD) of a general IEEE 802.16m system, and FIG. 2 shows a frame structure of a relay station and a base station by time division duplex (TDD). , Respectively.

  In FIG. 1, it can be seen that the uplink and the downlink are classified according to the frequency, and the connection area and the relay area are each assigned 4 subframes within one frame. In FIG. 2, it is understood that the uplink and the downlink are divided by time division, and the connection area and the relay area are again divided by time division within each uplink / downlink. However, in common with FIGS. 1 and 2, there is a gap (GAP) for changing the region between the regions.

  In the frame structure described above, a relay station (ARS) can broadcast its system information through a super frame header (SFH) in a downlink connection area. The relay station can transmit system information configured with the same field as the SFH transmitted by the base station. At this time, the values of these fields may be different from the values transmitted by the base station. However, the base station identifier field includes its own base station identifier that is not its own identifier. This is because a base station identifier that is not a relay station identifier is required in the terminal handover process.

  However, the relay station has additional system information that is not used by the base station (ABS) in addition to the system information broadcast through SFH due to its characteristics. Examples of such additional system information include information indicating a connection area and a relay area in the uplink / downlink, and a position and / or size of a gap (GAP) existing between the areas.

  A method of efficiently transmitting additional system information for the relay station to the terminal or its lower relay station will be described below with reference to an embodiment of the present invention.

According to one embodiment of the first embodiment the present invention, a method of transmitting additional system information for a relay station to efficiently terminal or a lower RS is provided.

  First, a method for notifying each area information in the downlink according to an embodiment of the present invention will be described.

  The reason why the information of each area must be notified to the terminal or its lower relay station in the downlink is that data transmitted from the base station to the corresponding relay station by the terminal or the lower relay station is directed to itself (actually noise). Because it may be recognized as interference. In addition, in the case of a lower relay station, if the transmission area of data transmitted to itself or signaling is known, it is not necessary to read A-MAP information in an unnecessary area.

  For this purpose, in this embodiment, it is proposed to notify the downlink / uplink area information (relay area information and connection area information) through the A-MAP area in the downlink subframe. Such a method will be described with reference to FIGS.

  FIG. 3 shows an example of a mode for informing area information of a relay station through a map area according to an embodiment of the present invention.

  Referring to FIG. 3, the A-MAP region of the first downlink subframe includes information on the type, length, and gap of the current region and information on the type, length, and gap of the next region. be able to. In the A-MAP area of the subframe in which the next area starts, information on the type, length, and gap of the corresponding area, and information on the type, length, and gap of the next area can be included. In this way, when the next area after the current area is a case where the relay station operates in the reception mode (for example, the downlink relay area), the terminal or the lower relay station receives the signal in the corresponding area. It turns out that it is not for itself, and after the next area is over, the signal of the corresponding relay station can be received again.

  Although FIG. 3 shows only the case of the downlink subframe, information on the uplink region can also be included in the corresponding uplink A-MAP region.

  FIG. 4 shows another example of a mode for informing relay station area information through a map area according to an embodiment of the present invention.

  Referring to FIG. 4, in the A-MAP area of the first downlink subframe, not only the information of the area to which the corresponding subframe belongs, but also the entire area information and gap information in the corresponding superframe are transmitted. be able to. In such a case, when the terminal or the lower relay station successfully receives the A-MAP area of the first subframe, additional reception of information for knowing the next area information is not required.

  On the other hand, the region information and the information on the gap of each region may be transmitted in the A-MAP region of each subframe.

  In addition to the method of transmitting the region information and the gap of each region through the A-MAP region, the region information and SFA that transmits essential system information or the AAI_SCD message that transmits additional system information are transmitted. Can do. At this time, the lower relay station must not allow the terminal and its own lower relay station to enter the network until the information is received.

  Next, a method for transmitting hop information (Odd-Hop or Even Hop), the number of hops (Hop count), and a relay identifier according to the present embodiment will be described. In order to assume the relationship between the base station and the relay station and between the relay station and another relay station, reference is made to FIG.

  FIG. 5 shows an example of a network arrangement form of a base station and its lower relay stations.

  When assuming the network arrangement as shown in FIG. 5, the hop information can be explained separately between the base station and the relay station and between the relay station and the relay station.

  1) Due to the relationship between ABS and ARS1, or ABS and ARS2, through the ABS superframe header, ARS1 or ARS2 implicitly determines its own hop information or when ARS1 or ARS2 enters the ABS. The ABS can inform that the corresponding relay station is an odd-hop through a medium connection control management message (MAC management message) transmitted in this process.

  2) Due to the relationship between ARS 1/2 and ARS 3/4, when ARS 1/2 broadcasts its own hop information through SFH, ARS 3/4 may implicitly determine its own hop information, or ARS 3/4 may be ARS 1 ARS1 / 2 informs ARS3 / 4 of its own hop information when entering / 2 and implicitly determines the hop information to ARS3 / 4, or directly transmits the hop information of ARS3 / 4 through the MAC message. I can inform you. This is because ARS1 / 2 knows that it is an odd hop and since ARS3 / 4 is its immediate lower relay station, it can know that ARS3 / 4 is an even hop. .

  Similar to the method described above, the number of hops can also be known to the relay station through SFH broadcast from a higher individual (that is, a base station or a higher relay station) or a MAC message in an entry process. If SFH is used, the relay station can implicitly determine the number of hops of the relay station by adding 1 to the number of hops of its own individual. If a MAC message is used, the upper individual informs the lower individual that enters its hop count in the same manner as SFH, or the upper individual directly informs the hop number of the lower relay station. You can also.

  On the other hand, here, the relay station identifier is an identifier for the relay station to distinguish between each other in the relationship between other relay stations / other terminals, for example, the relationship between ARS1 and ARS3 / AMS1. say. As the relay station identifier, a method of receiving assignment of a dedicated identifier from the base station may be used, and at this time, the dedicated identifier may be a station identifier (STID). As a method for transmitting such an identifier, a method is used between the base station and the odd-hop relay station, which receives a relay station identifier assignment through a MAC management message when the relay station enters the base station. be able to. In addition, when the upper relay station transmits the identifier given from the base station to the lower relay station through the superframe header or when the lower relay station makes an entry to the upper relay station between the upper relay station and the lower relay station. A method of transmitting a relay station identifier assigned from a base station to a lower relay station through a MAC message can be used.

  Meanwhile, according to another aspect of the present embodiment, a method is provided in which a relay station efficiently receives additional broadcast information of a base station in a broadband wireless access system including the relay station. First, additional broadcast information will be described.

  In general, the base station additionally transmits broadcast information (ABI: Additional Broadcast Information) necessary for communication with each terminal (for example, AAI_SCD, AAI_NBR-ADV, AAI_PAG-ADV, AAI_MC-ADV, etc.). Etc.) to the terminal. At this time, an additional broadcast message is transmitted through a traffic channel through which general user data is transmitted. The ABI includes extended system parameters (extended system parameters), system configuration information (system configuration information), and control information for downlink notification (DL notification).

  These pieces of information are information necessary after the system information acquisition (system acquisition) as described below.

-Information for handover: Default HO RSSI and CINR averaging parameter, Hysteresis margin, Time-to-Trigger trigger, Trigger information
-Information for MIMO technique (Information for MIMO): codebook subset for PMI coordination, Codebook subset for DL MU-MIMO subset indication
-Information for Relay: Hop information, DL / UL allocation, Transmit / receive zone, Zone type
-Information for Multi-Carrier: Carrier index, Fully / Partially configured carrier indication, Center frequency, Indication, Bandwidth information, Initiation
-Information for Femtocell (Information for FemtoCell)
-Improved multicast broadcasting service (Information for EMBS): Service ID, MSCCH resource allocation information
-Information for inter-RAT communication: MIH capability support
-Information for neighbor advertisement: characteristics of neighbor BS
-Control and signaling information transmitted to the DL in order to provide network notifications for single / group users in idle / sleep mode (DL and provisioned network notifications to the DL) group of users in the idle mode and sleep mode broadcast The base station generally transmits an additional broadcast message including the additional broadcast information described above in a downlink access zone (DL access zone), that is, a DL access zone. Mode). At this time, when the base station operates in the downlink connection region, the relay station also operates in the transmission mode (TX mode). Therefore, when the additional broadcast information (ABI) of the base station is changed, a method is required in which the relay station can efficiently receive the information. Hereinafter, a method for efficiently receiving the ABI of the base station at the relay station according to another aspect of the present embodiment will be described.

Method 1
The base station (or higher relay station) may additionally transmit an additional broadcast message through a DL relay zone. At this time, the base station (or upper relay station) can also transmit a message including the changed information to the downlink relay area only when the ABI is changed.

Method 2
The base station (or upper relay station) can always transmit additional broadcast messages through the downlink relay area.

Method 3
The relay station (or the lower relay station) can report the change count (Change count) of ABI and SFH to the base station (or the upper relay station). The base station (or higher-order relay station) that has received the message, if the corresponding relay station (or lower-order relay station) does not have the latest version of system information, a message containing the relevant system information in the relevant relay station Is transmitted.

Method 4
The base station (or upper relay station) can periodically transmit the change count of ABI and SFH to the relay station (or lower relay station). When the relay station (or lower relay station) receiving this information determines that the latest version of the system information is transmitted / applied from the version it owns, it requests transmission of a message including the corresponding information. be able to.

  In each method described above, the base station (or the upper relay station) can request the relay station (or the lower relay station) to receive or not receive the corresponding message.

Second Embodiment In another embodiment of the present invention, there is provided a method in which a relay station efficiently receives and updates updated system information when system information of a base station is changed.

  As described above, the relay station exchanges data with the terminal and exchanges data with the base station. However, since the relay station and the base station are synchronized with each other, their system information is broadcast at the same time. Accordingly, since the relay station broadcasts its own system information in the transmission mode when the base station broadcasts the system information, the relay station cannot receive the base station system information and cannot update it. Such a problem also occurs in the upper relay station and the lower relay station.

  Therefore, in this embodiment, it is proposed to define a separate MAC management message so that the relay station can receive and update the system information of the base station or the upper relay station changed through the message.

  The system information updated at the base station can be referred to as essential system information (ESI), which is usually transmitted through a secondary superframe header (S-SFH), and includes subpackets 1 to 3 (ie, , S-SFH SP1, S-SFH SP2, S-SFH SP3). Each subpacket may have a different transmission period and may be individually updated at the base station.

  The relay station can determine whether the system information of the base station (or the higher relay station) has been changed through a superframe header change count (SFH change count). The SFH change count of the base station (or upper relay station) can be transmitted to the relay station (or lower relay station) through the improved map area (A-MAP region). In this case, the SFH change count transmission area may be an extended non-user specific or non-user specific area, or a user specific area. On the other hand, the map area may include not only SFH change count information but also transmission position information of system information separately transmitted for the lower relay station. When the transmission position information is included in the improved map area, the lower relay station can grasp whether or not the corresponding information has been changed, and if it has been changed, can attempt to update it.

1) Transmission form of MAC message Form of MAC message (hereinafter referred to as “relay station essential system information message” or “RS_ESI message” for convenience) for transmitting the changed system information of the base station to the lower relay station May be in the form of a broadcast message or an additional broadcast message. Alternatively, considering the channel state and the like, each relay station (ARS) is grouped, one multicast identifier (multicast ID) is assigned to the same group, and a multicast message (to be transmitted to each relay station having the corresponding identifier) ( It may be in the form of a multicast message, or may be in the form of a unicast message.

  Unlike the general MAC management message, the corresponding message may not include operations such as encryption and security, and related information.

2) Form of MAC message On the other hand, the form of such RS_ESI message is transmitted in the form of one message including system information in all SFHs, or P-SFH and each S-SFH SP. It is also possible to transmit the system information in the form of each message. Alternatively, a method may be used in which a bit map is used to indicate whether or not each subpacket is included, and only the subpacket in which the bit is set is included. For example, when the bitmap is 4 bits, 1st bit: information in P-SFH, 2nd bit: information in S-SH SP1, 3rd bit: information in S-SFH SP2, 4th bit: S-SFH SP3 Each bit can be assigned as in the information within. However, since the P-SFH has little relation to the essential system information itself, the bit map can be 3 bits and subpackets 1 to 3 can be assigned to each bit. In addition, the MAC message for system information transmission preferably includes count information that is SFH version information.

  At this time, the transmitted system information can be configured by removing information that is not changed and unnecessary information such as BS ID.

3) MAC message transmission time point As long as at least one relay station exists in the base station, the base station must transmit a corresponding MAC message to each relay station at the following transmission time point.

The transmission time of the RS_ESI message may be periodic, and the period is independent or identical to the period of each subpacket of the base station SFH (N × P _{S-SFH SPx} , N ≧ 1). Can be set to At this time, the base station can also notify scheduling information such as transmission position and period information of the RS_ESI message in the network entry process. Also, the RS_ESI message transmission time point can be limited only to the case where the relay station requests it. As another transmission time of the RS_ESI message, it may be transmitted on the condition that the system information is changed in the base station by an event triggered method. At this time, the relay station can inform the base station whether or not the corresponding message has been received.

  As a method for the relay station to inform the base station whether or not the RS_ESI message is received, a header such as MAEH (Message ACK Extended Header) or a MAC message such as MR_Gereric-ACK or AAI_MSG-ACK can be used. If a message for confirming whether or not reception has been received from a specific relay station, or if a message indicating reception failure is received, the base station can retransmit it only to the corresponding relay station.

4) Application time point of updated system information The time point when the relay station applies the updated system information included in the RS_ESI message can be immediately applied to the corresponding superframe in which the RS_ESI message is received. A frame or a super frame may be determined and applied. In another method, the RS_ESI message may include information on a time point applied to the entire subpacket, and the application may be performed simultaneously on the entire subpacket. Alternatively, the application time may be changed for each subpacket so that the RS_ESI message includes information on the time applied for each subpacket, and such time can be set in units of superframes.

  Table 1 below shows an example of the content of an RS_ESI message according to another embodiment of the present invention.

  Referring to Table 1, whether the updated system information of the base station included in the RS_ESI message includes the updated system information of the base station for each sub-packet through a 3-bit bitmap (S-SFH information bitmap) field. Whether or not can be instructed separately. At this time, the updated system information of the base station included in the RS_ESI message is a type form (0b00: SP1, 0b01: SP2, 0b10: SP3) instead of the form of a 3-bit bitmap (S-SFH information bitmap). Can be instructed.

  Also, a secondary super frame header count (S-SFH change count) is included, and an S-SFH count of the corresponding message can be indicated. On the other hand, the RS_ESI message includes a super-frame number action (Super-frame Number Action) field, and superimposes the time when the system information (that is, each subpacket) included in the corresponding message is collectively applied. It can be expressed in units of frames.

  Table 2 below shows another example of the content of the RS_ESI message according to another embodiment of the present invention.

  Table 2 has basically the same configuration as Table 1. However, a super frame number action (Super-frame Number Action) field is included for each subpacket, and can be set by changing the application time point for each subpacket.

  The RS_ESI message including the information shown in Table 1 and Table 2 above additionally transmits a MAC message (for example, an AAI_MSG-ACK message) for the relay station that has received the message to confirm whether or not the corresponding message is received. It may further include information indicating an uplink resource allocated as possible (eg, frequency axis start offset of allocated resource, allocated resource size, allocated resource time axis position, etc.). . At this time, the uplink resource allocation order can be determined according to the ascending order or descending order of the RSID values.

  A specific form to which the above-described RS_ESI message is applied will be described with reference to FIG.

  FIG. 6 shows an example of a procedure in which a relay station according to another embodiment of the present invention updates base station system information.

  In FIG. 6, it is assumed that the RS_ESI format as shown in Table 2 is used, and the RS_ESI message is transmitted in an event trigger method that is conditional on the occurrence of system information update of the base station. Further, it is assumed that the relay station uses an AAI_MSG-ACK message to inform the base station whether or not an RS_ESI message has been received.

  Referring to FIG. 6, when the system information is updated in the base station (ABS) (S601), the base station can inform the relay station of the updated system information through an RS_ESI message (S602).

  At this time, the base station allocates an uplink resource (UL grant for AAI_MSG-ACK or ACK grant) for transmitting an AAI_MSG-ACK message for the relay station to inform the base station of the RS_ESI message transmission result to the relay station. (S603).

  At this time, the form of UL grant, that is, ACK grant will be described in more detail later.

  The relay station that has successfully received the RS_ESI message can transmit the AAI_MSG-ACK message to the base station through the uplink resource indicated by the UL grant information to inform the base station of the successful reception of the RS_ESI message ( S604).

  Thereafter, the relay station includes the update information of each subpacket corresponding to the bit set to '1' in the bitmap (S-SFH information bitmap) included in the RS_ESI message in the update information of each subpacket. The super frame number action (Super-frame Number Action) field can be applied to each sub-packet in the super frame (S605).

  If the AAI_MSG-ACK message of step S604 is not received, the BS can retransmit the RS_ESI message to the RS again. At this time, the re-transmission is performed in the super-frame number action field. It can be done before the indicated time.

  Hereinafter, a specific form in which a BS transmits an uplink resource (UL Grant for AAI_MSG-ACK or ACK Grant) for transmitting an AAI_MSG-ACK message according to another embodiment of the present invention to a relay station will be described. explain.

1) Transmission of ACK grant through improved map information element (A-MAP IE) Only allocation information for relay station (or lower relay station) to transmit ACK message to base station (or higher relay station) in ACK grant , An example of a form of a map information element (A-MAP IE) for transmitting an ACK grant to all relay stations connected to the base station is described with reference to Table 3 below. To do.

  Referring to Table 3, the map information element including the ACK grant information includes resource allocation information (that is, start offset and allocation size) that can be used by all relay stations connected to the base station. Can do. Here, the CRC of the map may be masked with a broadcast ID.

  If a relay station to which a resource for ACK message transmission is allocated is specified, a bitmap can be used, and the form of the map information element for this purpose is as shown in Table 4 below.

  Referring to Table 4, a bitmap field indicating a relay station to which resources are allocated is included in the map information element. At this time, the order in which each field of the bitmap is assigned can follow the RSID.

2) Transmission of ACK grant through improved map information element (A-MAP IE) using multicast identifier (multicast ID) In the following, referring to Table 5 and Table 6, all having a specific multicast identifier (multicast ID) The design form of the map information element for assigning ACK grant to the relay station of will be described. At this time, the multicast identifier may be the same as the multicast identifier for the RS_ESI message.

  Referring to Table 5, the form of the map information element including the ACK grant information is similar to the structure of the map information element of Table 3, but the CRC is masked with a multicast identifier. At this time, through the MCRC information, the relay station knows which multicast identifier for the corresponding map information element includes ACK grant information.

  In the case of designating a relay station to which resources for ACK message transmission are assigned, a bitmap can be used, and the format of the map information element for this purpose is as shown in Table 6 below.

  Referring to Table 6, a bitmap field indicating a relay station to which resources are allocated is included in the map information element. At this time, the order in which the fields of the bitmap are assigned can follow the RSID.

  On the other hand, the map information element can indicate to which relay station the ACK grant is allocated in the form of a hierarchical bitmap. This will be described with reference to Table 7 below.

  Referring to Table 7, a map information element for ACK grant allocation includes a first level bitmap field and a relay station bitmap (ARS bitmap) field.

  Here, the first level bitmap represents the range of the relay station identifier (ARS ID). For example, assuming that the range is determined in units of 10, if the first bit is 1, each bit in the bit map of the relay station means a relay station having an identifier of 0bxxxxxxx0000001 to 0bxxxx0001010, and the second bit is When it is 1, each bit of the bitmap of the relay station means a relay station having an identifier of 0bxxxxxxxx01101 to 0bxxxxxxxx0010100.

  If the bitmap field of the relay station is not included in the map information element, it may mean that it is assigned to all ARSs in the corresponding range.

  Further, in order to indicate the relay station to which the ACK grant is assigned, a method of expressing the start relay station identifier and the number of relay stations to which the ACK grant is assigned from the start relay station identifier may be used. This will be described with reference to Table 8.

  Referring to Table 8, a start relay station identifier (Start number of ARS ID) field and a number of relay stations (The number of ARSs) field are included in a map information element for ACK grant assignment, and ACK grant is It can represent which relay station is assigned.

  For example, if the starting relay station identifier field value is 0bxxxxxxx0011101 and the relay station number field value is 2, it indicates that the corresponding ACK grant is assigned to the relay station having the identifiers of 0bxxxxxxxx101 and 0bxxxx0011110.

  Each field included in the map information element (A-MAP IE) for ACK grant allocation described above may be included in a predetermined MAC management message. In addition, if the ACK grant is not allocated until a specific time (timer or duration, for example, the next superframe), the RS requests an uplink resource for transmitting an ACK message through a random access process. You can also In this process, if there is a valid resource, the relay station transmits an ACK message to the base station (or upper relay station) through the corresponding resource without waiting for the allocation of the uplink resource through the ACK grant or the arbitrary connection process. It can also be communicated.

  Hereinafter, a method for assigning a multicast identifier (Multicast ID) and a relay station identifier (RSID) according to another embodiment of the present invention will be described.

1) Relay station identifier (RSID)
The relay station identifier is a target identifier for distinguishing the relay station at the interface between the base station / upper relay station and the lower relay station. The base station / upper relay station can assign such a relay station identifier in the initial entry process of the lower relay station. At this time, the assigned identifier may be a 12-bit station identifier (STID).

2) Multicast identifier (Multicast ID)
The base station and the upper relay station must transmit the changed SFH information to its lower relay station. At this time, the RS_ESI message including the corresponding changed SFH information may be transmitted to the lower relay station using a multicast method. Accordingly, the base station and the upper relay station can assign multicast identifiers (multicast IDs) of all lower relay stations through a relay station setting (ARS configuration) process, that is, a relay station setting command (RS configuration command) message. .

  Hereinafter, a multicast identifier assignment method according to another embodiment of the present invention will be described in more detail.

  According to the present embodiment, the x bit-MSB value of the identifier of the lower relay station having the same multicast identifier (Multicast ID) can be set to be the same as the x bit-MSB value of the multicast identifier. This will be described with reference to FIG.

  FIG. 7 shows an example of a relay station identifier and multicast identifier setting method according to another embodiment of the present invention.

Referring to FIG. 7, in the case of the left side, assuming that the multicast ID is 11101 0000000 and x is 5, the range of relay station identifiers in the corresponding multicast ID is 11101 0000001 to 11101 1111111. In the case of the right side, assuming that the multicast ID is 11110 0000000 and x is 5, the range of relay station identifiers in the corresponding multicast ID is 11110 0000001 to 11110 1111111. In FIG. 7, the base station is shown to assign identifiers to each relay station in ascending order, but this is exemplary, and the assignment of relay station identifiers can also be in descending order.

  In response to the message transmitted through the Multicast ID (that is, the RS_ESI message), the base station and the upper relay station can notify whether or not the corresponding message is received. At this time, since the upper relay station and the base station know the total number of lower relay stations existing in the corresponding Multicast ID, they can notify the presence / absence of reception in the form of RS_ESI message or A-MAP IE. Possible uplink resources can be allocated.

Structure of Terminal and Base Station Hereinafter, as still another embodiment of the present invention, a terminal and a base station (FBS, MBS) capable of implementing each of the above-described embodiments will be described.

  A terminal may operate as a transmitter on the uplink and as a receiver on the downlink. In addition, the base station can operate as a receiver in the uplink and operate as a transmitter in the downlink. That is, the terminal and the base station can include a transmitter and a receiver for transmitting information or data.

  The transmitter and receiver can include processors, modules, portions, and / or means for performing embodiments of the invention. In particular, the transmitter and the receiver may include a module (means) for encrypting the message, a module for analyzing the encrypted message, an antenna for transmitting and receiving the message, and the like. An example of such a transmitting end and a receiving end will be described with reference to FIG.

  FIG. 8 is a block diagram showing an example of a transmission end and reception end structure as still another embodiment of the present invention.

  Referring to FIG. 8, the left side shows the structure of the transmitting end, and the right side shows the structure of the receiving end. Each of the transmitting end and the receiving end may include antennas 5, 10, processors 20, 30, transmission modules (Tx module) 40, 50, receiving modules (Rx module) 60, 70 and memories 80, 90. Each component can perform a function corresponding to each other. Below, each component is demonstrated in detail.

  The antennas 5 and 10 perform a function of transmitting signals generated by the transmission modules 40 and 50 to the outside and receiving radio signals from the outside and transmitting them to the reception modules 60 and 70.

  If a multiple antenna (MIMO) function is supported, more than one antenna can be provided. Together, the antenna, the transmission module, and the reception module may constitute a radio communication (RF) module.

  The processors 20 and 30 usually control the overall operation of the entire mobile terminal. For example, a controller function for performing the above-described embodiments of the present invention, a MAC (Medium Access Control) frame variable control function according to a service environment and a propagation environment, a handover (Hand Over) function, an authentication and encryption function, etc. be able to. More specifically, the processors 20 and 30 can perform general control for performing the above-described system information transmission / update procedure.

  In particular, the processor of the relay station can control the wireless communication module to receive the RS_ESI message from the base station, and obtain the updated system information of the base station included in the RS_ESI message. The processor of the relay station can apply the system information updated in units of subpackets at the corresponding time using the field indicating the update time for each subpacket of the acquired system information. Also, the processor of the relay station can control the wireless communication module such that an AAI_MSG-ACK message is transmitted to the base station to inform the base station of successful reception of the RS_ESI message. At this time, an uplink resource for transmitting the AAI_MSG-ACK message can be allocated through an A-MAP IE or MAC management message that is CRC-masked with a predetermined broadcast identifier or multicast identifier.

  In addition, the processor of the relay station can perform a general control operation of the operation process disclosed in the above-described embodiments.

  The transmission modules 40 and 50 may perform predetermined coding and modulation on the data scheduled and transmitted to the outside by the processors 20 and 30 and then transmit the data to the antenna 10. it can.

  The receiving modules 60 and 70 perform decoding and demodulation on radio signals received from the outside via the antennas 5 and 10, restore them to the form of original data, and transmit them to the processors 20 and 30. can do.

  The memories 80 and 90 can store programs for processing and control of the processors 20 and 30, and can also perform functions for temporary storage of input / output data (ESI information and the like). Further, the memories 80 and 90 are a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (for example, SD or XD memory). , RAM (Random Access Memory), SRAM (Static Random Access Memory), ROM (Read-Only Magnetic, Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory, Read-Only Memory) Light It may include at least one type of storage medium of the disk.

  On the other hand, the base station and the relay station have a controller function, an orthogonal frequency division multiple access (OFDMA) packet scheduling, a time division duplex (TDD) for performing each of the embodiments of the present invention described above. ) Packet scheduling and channel multiplexing function, MAC frame variable control function according to service characteristics and propagation environment, high-speed traffic real-time control function, handover function, authentication and encryption function, packet modulation / demodulation function for data transmission, The high-speed packet channel coding function and the real-time modem control function are performed through at least one of the modules described above. Etc. can further include additional means, module or part for performing such functions as.

  The present invention may be embodied in other specific forms without departing from the spirit and essential characteristics of the invention. Accordingly, the above detailed description should not be construed as limiting in any respect and should be considered as exemplary. The scope of the invention should be determined by reasonable analysis of the appended claims, and all modifications within the equivalent scope of the invention are included in the scope of the invention. In addition, claims which do not have an explicit citation relationship in the claims can be combined to constitute an embodiment, or can be included as a new claim by amendment after application.

Claims (15)

A method of updating advanced base station (ABS) system information by an advanced relay station (ARS) in a wireless communication system, the method comprising:
Receiving ABS system information broadcast periodically from an advanced base station;
Performing a network entry with the advanced base station;
Broadcasting the ARS system information while the advanced base station is broadcasting the ABS system information;
Receiving, from the advanced base station, a first message including update information related to the updated parameter of the ABS system information when the parameter of the ABS system information is updated in the advanced base station;
Transmitting a second message for confirmation of receipt of the first message to the advanced base station;
Applying the update information. The ABS system information includes at least one of a first subpacket, a second subpacket, and a third subpacket,
The update information includes a change count field indicating a change count of the ABS system information, and a bitmap field indicating whether each of the subpackets is included in the first message,
The method of claim 1, wherein the bitmap field includes a first bit, a second bit, and a third bit, respectively, for indicating the presence of each of the subpackets. The update information further includes a super frame number action field indicating a time point at which the update information included in the first message is applied in a super frame unit,
The method of claim 2, wherein the update information is applied at a time indicated by the superframe number action field.   The method according to claim 1, wherein the first message is received from the advanced base station every time a parameter of the ABS system information is updated.   The method of claim 1, wherein the first message is an advanced relay station essential system information message and the second message is a message ACK message. A method of updating advanced base station (ABS) system information received at an advanced relay station (ARS) by an advanced base station in a wireless communication system, the method comprising:
Performing a network entry procedure for the advanced relay station;
Periodically broadcasting the ABS system information while the advanced relay station periodically broadcasts ARS system information;
Updating parameters of the ABS system information in the advanced base station;
Transmitting a first message including update information related to an updated portion of the ABS system information to the advanced relay station;
Receiving from the advanced relay station a second message for confirmation of receipt of the first message. The ABS system information includes at least one of a first subpacket, a second subpacket, and a third subpacket,
The update information includes a change count field indicating a change count of the ABS system information, a bitmap field indicating whether each of the subpackets is included in the first message, and a superframe unit. A superframe number action field indicating a time point at which the update information included in the first message is applied;
The method of claim 6, wherein the bitmap field includes a first bit, a second bit, and a third bit, respectively, for indicating the respective presence of the subpacket.   The method according to claim 6, wherein the first message is transmitted each time a parameter of the ABS system information is updated.   7. The method of claim 6, further comprising retransmitting the first message to the advanced relay station if the second message is not received from the advanced relay station.   The method according to claim 6, wherein the first message is an advanced relay station essential system information message, and the second message is a message ACK message. An advanced relay station (ARS) in a wireless communication system, wherein the relay station is
A processor;
A radio frequency (RF) module for transmitting a radio signal to the outside and receiving a radio signal from the outside under the control of the processor;
The processor controls the radio frequency module to receive advanced base station (ABS) system information from the advanced base station, to perform network entry with the advanced base station, and the advanced base station There running and to broadcast the ARS system information while broadcasting the ABS system information,
When the parameter of the ABS system information is updated in the advanced base station, the processor includes update information related to the updated parameter of the ABS system information by controlling the radio frequency module. To receive the first message from the advanced base station, transmit a second message for confirming reception of the first message to the advanced base station, and control so that the update information is applied. A relay station that executes things. The ABS system information includes at least one of a first subpacket, a second subpacket, and a third subpacket,
The update information includes a change count field indicating a change count of the ABS system information, and a bitmap field indicating whether each of the subpackets is included in the first message,
The relay station according to claim 11, wherein the bitmap field includes a first bit, a second bit, and a third bit, respectively, for indicating the presence of each of the subpackets. The update information further includes a super frame number action field indicating a time point at which the update information included in the first message is applied in a super frame unit,
The relay station according to claim 12, wherein the processor controls the update information to be applied at a time indicated by the superframe number action field.   The relay station according to claim 11, wherein the first message is transmitted from the base station every time a parameter of the ABS system information is updated.   The relay station according to claim 11, wherein the first message is an advanced relay station essential system information message, and the second message is a message ACK message.