# Patent

## Title
Apparatus and method for transmitting a MAC PDU based on MAC header type information

## Abstract

An Apparatus and methods for communicating in a wireless access system using a medium access control protocol data unit (MAC PDU) is disclosed. The method comprises steps of receiving, by a mobile station (MS) from a base station (BS), a dynamic service addition request (AAI_DSA-REQ) message requesting to create a service flow, wherein the AAI_DSA-REQ message comprises a first MAC header type parameter indicating a type of a MAC header included in the MAC PDU of the service flow and a flow identifier (FID) identifying a connection associated with the service flow; transmitting, by the MS to the BS, a dynamic service addition response (AAI_DSA-RSP) message in response to the AAI_DSA-REQ message, wherein the AAI_DSA-RSP message comprises a second MAC header type parameter indicating the type of a MAC header included in the MAC PDU of the service flow; and communicating with the BS using the MAC PDU comprising the MAC header indicated by the second MAC header type parameter; wherein the MAC header type parameter indicates one of a generic MAC header (GMH) for general data packet transmission and a short-packet MAC header (SPMH) for small data packet transmission and a non-ARQ connection.

## Background
This application is the National Phase of PCT/KR2010/005961 filed on Sep. 2, 2010, which claims priority under 35 U.S.C. 119(e) to U.S. Provisional Application Nos. 61/239,077 filed on Sep. 2, 2009 and 61/255,475 filed on Oct. 27, 2009 and under 35 U.S.C. 119(a) to Patent Application No. 10-2010-0033172 filed in Korea on Apr. 12, 2010, all of which are hereby expressly incorporated by reference into the present application.


TECHNICAL FIELD
The present invention relates to a mobile communication system, and more particularly, to an apparatus for transmitting and receiving MAC PDU (medium access control protocol data unit) using MAC header type information and method thereof.
BACKGROUND ART
Generally, an internet based communication system includes a protocol stack consisting of five layers. And, a configuration of each protocol layer is shown in FIG. 1.
FIG. 1 is a diagram for one example of an internet protocol stack used in general.
Referring to FIG. 1, an internet protocol stack consists of an application layer (i.e., a most upper layer), a transport layer, a network layer, a link layer and a physical layer in order. The application layer is the layer for supporting such a network application as FTP (File Transfer Protocol), HTTP (Hypertext Transfer Protocol, TCP (Transmission Control Protocol), UDP (User Datagram Protocol) and the like. The transport layer is the layer responsible for an inter-host data transport function using TCP/UDP. The network layer is the layer for setting a data transport path from a source to a destination via the transport layer and IP protocol. The link layer is the layer responsible for data transmission between neighbor network entities and MAC (medium access control) via PPP/Ethernet protocol and the like. And, the physical layer is a lowest layer for performing a data transmission by a bit unit using a wire/wireless medium.
FIG. 2 is a diagram for operation of each layer for data transmission used in general.
Referring to FIG. 2, a transport layer of a transmitting side generates a new data unit by adding header information H+ to a message payload M received from an application layer that is an upper layer. The transport layer transfers the new data unit to a network layer that is a lower layer. The network layer generates a new data unit by adding header information Hn used by the network layer to the data received from the transport layer and then transfers this data unit to a link layer that is a lower layer.
Subsequently, the link layer generates a new data unit by adding header information H1 used by the link layer to the data received from the upper layer and then transfers it to a physical layer that is a lower layer. The physical layer transfers the data unit received from the link layer to a receiving side.
Meanwhile, a physical layer of the receiving side receives the data unit from the transmitting side and then transfers the received data unit to a link layer that is an upper layer of the physical layer. The receiving side processes a header added to each layer and then transfers the header removed message payload to an upper layer. Through this process, data transceiving is performed between the transmitting side and the receiving side.
For the data transceiving between the transmitting side and the receiving side, as shown in FIG. 2, each layer adds a protocol header and then performs such a control function as data addressing, routing, forwarding, data retransmission and the like.
FIG. 3 is a diagram of a protocol layer model defined in a wireless mobile communication system based on IEEE 802.16 system used in general.
Referring to FIG. 3, a MAC layer belonging to a link layer can consist of three sublayers.
First of all, a service-specific convergence sublayer (service-specific CS) modifies external network data received via a convergence sublayer service access point (CS SAP) into MAC SDUs (service data units) of a MAC sublayer (common part sublayer: CPS) or maps the corresponding data. This layer can include a function of sorting SDUs of external network and then linking a corresponding MAC service flow identifier (SFID) with a connection identifier (CID).
Secondly, a MAC CPS is a layer of providing such a core function of the MAC as system access, bandwidth allocation, connection setting and management and the like. The MAC CPS receives data sorted by a specific MAC connection from various convergence sublayers via the MAC SAP. In this case, a QoS (quality of service) is applicable to the data transmission and scheduling via a physical layer.
Thirdly, a security sublayer is able to provide such a function as authentication, security key exchange and encryption.
The MAC layer is a connection-oriented service and is implemented with the concept of transport connection. When a mobile station registers with a system, a service flow can be provided by a negotiation between a mobile station and a system. If a service request is changed, a new connection can be set. In this case, the transport connection defines mapping between peer convergence processes using MAC and service flow. And, the service flow defines QoS parameters of MAC PDU exchanged in the corresponding connection.
The service flow on the transport connection plays a core role in managing and operating the MAC protocol and provides a mechanism for uplink and downlink QoS managements. In particular, service flows can be combined with a bandwidth allocation process.
In the general IEEE 802.16 system, a mobile station is able to have a 48-bit universal MAC address for each radio interface. This address uniquely defines a radio interface of a mobile station and is usable to set an access of the mobile station during an initial ranging process. Since a base station verifies mobile stations using different identifiers (ID) of the mobile stations, respectively, the universal MAC address is usable as a portion of an authentication process.
Each connection can be identified by a 16-bit connection identifier (CID). While initialization of a mobile station is in progress, two management connection pairs (i.e., uplink and downlink) are established between a mobile station and a base station. And, three pairs including the management connections are selectively usable.
In order for a transmitting end and a receiving end to exchange data with each other in the above described layer structure, assume a case of transmitting MAC SDUs (medium access control service data units). In this case, the MAC SDU is processed into MAC PDU (medium access control packet data unit). In order to generate such a MAC PDU, a base station or a mobile station enables a MAC header to be included in the corresponding MAC PDU.
DISCLOSURE OF INVENTION
Technical Problem
Generally, in case of applying segmentation, packing or automatic retransmit request (ARQ) to a packet to transmit, it is able to use a fragmentation & packing extended header among extended headers to enable relevant information to be included in a corresponding MAC PDU.
In this case, data, which is generated in a fixed small size with predetermined periodicity like a voice packet such as VoIP (voice over internet protocol), is generally transmitted without having segmentation or packing. Moreover, in case of performing an error check, hybrid automatic retransmit request (HARQ) reordering applied to MAC PDU unit is used instead of ARQ reordering applied to MAC SDU unit. Therefore, when HARQ reordering is substantially performed on such a packet as VoIP, MAC PDU is accompanied by FPEH to include a sequence number for a corresponding data required for discriminating retransmitted data from new data transmitted next to the retransmitted data.
However, in this case, even if FPEH having a size of minimum 2 byte is added to a VoIP packet, a size of a MAC header becomes equal to or greater than 3 bytes to result in unnecessary resource waste in case of VoIP packet transmission.
Solution to Problem
Accordingly, the present invention is directed to an apparatus for transmitting and receiving MAC PDU (medium access control protocol data unit) using MAC header type information and method thereof that substantially obviate one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide an efficient compact MAC header (i.e. a short-packet MAC header) structure including a sequence number and a method of providing a service using the same.
Another object of the present invention is to provide a more efficient method of providing a service by sharing information on a type of a MAC header to use for MAC PDU, which is to be transmitted, in the course of a service connection performed between a base station and a mobile station for MAC PDU transmission.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a method for communicating in a wireless access system using a medium access control protocol data unit (MAC PDU), the method comprises steps of receiving, by a mobile station (MS) from a base station (BS), a dynamic service addition request (AAI_DSA-REQ) message requesting to create a service flow, wherein the AAI_DSA-REQ message comprises a first MAC header type parameter indicating a type of a MAC header included in the MAC PDU of the service flow and a flow identifier (FID) identifying a connection associated with the service flow; transmitting, by the MS to the BS, a dynamic service addition response (AAI_DSA-RSP) message in response to the AAI_DSA-REQ message, wherein the AAI_DSA-RSP message comprises a second MAC header type parameter indicating the type of a MAC header included in the MAC PDU of the service flow; and communicating with the BS using the MAC PDU comprising the MAC header indicated by the second MAC header type parameter; wherein the MAC header type parameter indicates one of a generic MAC header (GMH) for general data packet transmission and a short-packet MAC header (SPMH) for small data packet transmission and a non-ARQ connection.
Preferably, the AAI_DSA-REQ message further comprises service flow parameters specifying traffic characteristics and scheduling requirements of the service flow and convergence sublayer parameters encodings specifying convergence sublayer specific parameters. In this case, the service flow parameters comprise a link indicator indicating whether parameters for the MAC PDU transmission is uplink or a downlink. In addition, the small data packet may be a voice over internet protocol (VoIP) data packet which has a predetermined fixed size with a predetermined periodicity.
Preferably, the SPMH consists of the flow identifier (FID) field, an extended header group presence indicator (EH) field, a length field and a sequence number (SN) field. The FID field identifies the connection used for the transmission of the MAC PDU; the EH field indicates whether an extended header group is present following the SPMH; the length field indicates a length in bytes of the MAC PDU including the SPMH and an extended header if present; and the SN field indicates a payload sequence number of the MAC PDU and increments by one for each MAC PDU. The SN field is used for an HARQ (hybrid-automatic retransmission request) scheme.
To further achieve these and other advantages and in accordance with the purpose of the present invention, the present invention discloses station for communicating in a wireless access system using a medium access control protocol data unit (MAC PDU). The station comprises a transmitter; a receiver; and a processor configured to generate the MAC PDU, wherein the MAC PDU comprises a MAC header indicated by a MAC header type parameter determined during a dynamic service flow creation procedure, and wherein the MAC header type parameter indicates one of a generic MAC header (GMH) and a short-packet MAC header (SPMH).
Preferably, the processor comprises a convergence sublayer, a service data unit (SDU) fragmentation or packing function unit, and a MAC PDU formation module which are used for generating the MAC PDU.
Preferably, the dynamic service flow creation procedure is performed by exchanging a dynamic service addition request (AAI_DSA-REQ) message and a dynamic service addition response (AAI_DSA-RSP) message.
According to the other embodiment of the present invention, the station communicates with another station using the MAC PDU comprising the MAC header indicated by the second MAC header type parameter, and wherein the MAC PDU is constructed by the MAC PDU generating unit.
Preferably, the AAI_DSA-REQ message comprises service flow parameters specifying traffic characteristics and scheduling requirements of the service flow and convergence sublayer parameters encodings specifying convergence sublayer specific parameters. In this case, the service flow parameters comprise a link indicator indicating whether parameters for the MAC PDU transmission is uplink or a downlink and the MAC header type parameter.
Preferably, The AAI_DSA-RSP message comprises service flow parameters specifying traffic characteristics and scheduling requirements of the service flow and convergence sublayer parameters encodings specifying convergence sublayer specific parameters. In this case, the service flow parameters comprises a link indicator indicating whether parameters for the MAC PDU transmission is uplink or a downlink and the MAC header type parameter.
The small data packet of the present invention may be a voice over internet protocol (VoIP) data packet which has a predetermined fixed size with a predetermined periodicity.
Preferably, the SPMH consists of the flow identifier (FID) field, an extended header group presence indicator (EH) field, a length field and a sequence number (SN) field. In this case, the FID field identifies the connection used for the transmission of the MAC PDU; the EH field indicates whether an extended header group is present following the SPMH; the length field indicates a length in bytes of the MAC PDU including the SPMH and an extended header if present; and the SN field indicates a payload sequence number of the MAC PDU and increments by one for each MAC PDU.
The SN field is used for an HARQ (hybrid-automatic retransmission request) scheme.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
ADVANTAGEOUS EFFECTS OF INVENTION
Accordingly, the present invention provides the following effects or advantages.
First of all, the present invention performs communications more efficiently in a manner that information on a MAC header type is shared in the course of a service connection between a base station and a mobile station.
Secondly, the present invention uses a compact MAC header (i.e. SPMH) including sequence number (SN) information necessary for performing HARQ reordering on such a small packet as VoIP, thereby reducing a MAC header overhead according to a presence of an extended header.
Thirdly, a flow identifier (Flow ID) for identifying a corresponding service flow is included in a compact MAC header, whereby a receiving end receiving the compact MAC header is able to reduce a processing overhead generated from a flow mapping process.
Finally, the present invention is able to provide a more efficient service by sharing of information on a type of a MAC head to be used for a MAC PDU, which is to be transmitted next, in the course of a service connection between a base station and a mobile station for MAC PDU transmission.
It is to be understood that the effects that can be obtained by the present invention are not limited to the aforementioned effects, and another effects, which are not described, will be apparent to those skilled in the art to which the present invention pertains, from the following detailed description of the present invention.



BRIEF DESCRIPTION OF DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
In the drawings:
FIG. 1 is a diagram for one example of an internet protocol stack used in general;
FIG. 2 is a diagram for operation of each layer for data transmission used in general;
FIG. 3 is a diagram of a layer structure of a general IEEE 802.16 system;
FIG. 4 is a diagram of a connection and service flow (SF) used by an IEEE 802.16 system;
FIG. 5 is a diagram for one example of a MAC PDU (protocol data unit) type defined in a wireless MAN mobile communication system based on IEEE 802.16 system used in general;
FIG. 6 is a diagram for one example of a compact MAC header structure according to one embodiment of the present invention;
FIG. 7 is a diagram for one example of a process for a mobile station to perform a service connection for MAC PDU transmission to a base station according to another embodiment of the present invention;
FIG. 8 is a diagram for one example of a process for a base station to perform a service connection for MAC PDU transmission to a mobile station according to another embodiment of the present invention;
FIG. 9 is a diagram for another example of a process for a mobile station to perform a service connection for MAC PDU transmission to a base station according to another embodiment of the present invention;
FIG. 10 is a diagram for another example of a process for a base station to perform a service connection for MAC PDU transmission to a mobile station according to another embodiment of the present invention;
FIG. 11 is a diagram for one example of a MAC PDU generating unit in a transmitting device according to another embodiment of the present invention; and
FIG. 12 is a block diagram for describing a mobile station and a base station according to a further embodiment of the present invention for performing the above described embodiments of the present invention.



MODE FOR THE INVENTION
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
The present invention relates to MAC headers for efficient data transmissions in a wireless communication system.
First of all, the following embodiments correspond to combinations of elements and features of the present invention in prescribed forms. And, it is able to consider that the respective elements or features are selective unless they are explicitly mentioned. Each of the elements or features can be implemented in a form failing to be combined with other elements or features. Moreover, it is able to implement an embodiment of the present invention by combining elements and/or features together in part. A sequence of operations explained for each embodiment of the present invention can be modified. Some configurations or features of one embodiment can be included in another embodiment or can be substituted for corresponding configurations or features of another embodiment.
In the description of drawings, procedures or steps, which may ruin the substance of the present invention, are not explained. And, procedures or steps, which can be understood by those skilled in the art, are not explained as well.
In this disclosure, embodiments of the present invention are described centering on the data transmission/reception relations between a base station and a mobile station. In this case, the base station is meaningful as a terminal node of a network which directly performs communication with the mobile station. In this disclosure, a specific operation explained as performed by a base station can be performed by an upper node of the base station in some cases.
In particular, in a network constructed with a plurality of network nodes including a base station, it is apparent that various operations performed for communication with a mobile station can be performed by a base station or other networks except the base station. In this case, ‘base station’ can be replaced by such a terminology as a fixed station, a Node B, an eNode B (eNB), an advanced base station (ABS), an access point and the like. And, ‘mobile station (MS)’ can be replaced by such a terminology as a user equipment (UE), a subscriber station (SS), a mobile subscriber station (MSS), an advanced mobile station (AMS), a mobile terminal, a terminal and the like.
Moreover, a transmitting end means a stationary and/or mobile node that transmits a data service or a speech service. And, a receiving end means a stationary and/or mobile node that receives a data service or a speech service. Hence, a mobile station can become a transmitting end and a base station can become a receiving end, in uplink. Likewise, a mobile station becomes a receiving end and a base station can become a transmitting end, in downlink.
In particular, the steps or parts, which are not explained to clearly reveal the technical idea of the present invention, in the embodiments of the present invention can be supported by the above documents. Specifically, embodiments of the present invention can be supported by at least one of P802.16-2004, P802.16e-2005, P802.16e-2009 and P802.16m documents, which are the standards of IEEE 802.16 system.
In the following description, a preferred embodiment of the present invention is explained in detail with reference to the accompanying drawings. Detailed description disclosed together with the accompanying drawings is intended to explain not a unique embodiment of the present invention but an exemplary embodiment of the present invention.
In the following description, specific terminologies used for embodiments of the present invention are provided to help the understanding of the present invention. And, the use of the specific terminology can be modified into another form within the scope of the technical idea of the present invention.
FIG. 4 is a diagram of a connection and service flow (SF) used by an IEEE 802.16 system.
Referring to FIG. 4, in order to provide QoS of an upper service flow (SF), a logical connection of a MAC layer maps an SF to a logical connection for which a QoS parameter is defined. And, the logical connection is defined to provide QoS in a MAC layer through appropriate scheduling for data transmission of the corresponding connection. Types of connections defined in the MAC layer include a management connection (or, a control connection) allocated per mobile station for mobile station management in the MAC layer and a transport connection mapped to a service flow for upper service data transport.
All user data communications are in the context of transport connections. A transport connection is uni-directional, and identified by a unique flow identifier (FID) which is assigned during a DSA procedure (will be described hereinafter), excluding the transport connections associated with the default service flows. The transport connections for the default service flows in uplink and downlink direction are each identified by the pre-assigned FID and established by the registration procedure during network entry.
Each transport connection is associated with an active or admitted service flow to provide various levels of QoS required by the service flow. The transport connection is established when the associated active service flow is admitted or activated, and released when the associated service flow becomes inactive. Once established, the FID of the transport connection is not changed during wireless MAN-OFDMA advanced system handovers. To reduce bandwidth usage, the AMS and the ABS may establish/change/release multiple connections using a single DSx message transaction on a control connection.
Service flows can be pre-provisioned or dynamically created. Transport connections associated with pre-provisioned service flow are established by the DSA procedure triggered by completion of the MAS network entry. Especially the transport connections associated with the default service flows in uplink and downlink direction each are established with the pre-assigned FIDs by successful registration procedure.
On the other hand, AMS or ABS can create new service flows and their associated transport connections dynamically using DSA procedure if needed. A transport connection is created, changed or deleted when the associated service flow is created, changed or deleted respectively.
FIG. 5 is a diagram for one example of a MAC PDU (protocol data unit) type defined in a wireless MAN mobile communication system based on IEEE 802.16 system used in general.
In general, in a link layer below a second layer (i.e., a link layer or a MAC layer) and a physical layer, a header format of MAC PDU is defined different according to a protocol of such a system as LAN, Wireless LAN, 3GPP, 3GPP2, Wireless MAN and the like. MAC header contains a MAC or link address of a node for inter-node data forwarding in the link layer and is able to contain header error check and link layer control information.
Referring to FIG. 5, each MAC PDU starts with a MAC header of a predetermined length. The MAC header is located ahead of a payload of the MAC PDU. The MAC PDU can include an extended header group which comprising at least one extended header. The extended header is located behind the MAC header. In case that the extended header group is included, the payload is located behind the extended header group. The payload of the MAC PDU can include at least one subheader, a MAC SDU and a fragment. And, a length of payload information is changeable to represent a variable byte size. Accordingly, the MAC sublayer is able to transmit various traffic types of an upper layer without recognizing a format or bit pattern of a message. Besides, a cyclic redundancy check (CRC) for error detection can be included in the MAC PDU [not shown in FIG. 5].
There are MAC headers of three types. In particular, they can be classified into an advanced generic MAC header (AGMH) including a payload behind a header, a compact MAC header (CMH) for supporting such an application as VoIP, and a MAC signaling header for such a control as a bandwidth request and the like. Hereinafter, the CMH can be referred to as short-packet MAC header (SPMH).
The AGMH having the payload located behind the header is located at a start part of DL/UL MAC PDU including data of a MAC control message and a convergence layer (CS) and is called a generic MAC header (GMH) in IEEE 802.16e and the like.
Table 1 shows one example of an advanced generic MAC header (AGMH) structure used in a wireless communication system based on IEEE 802.16 system.









TABLE 1






Size



Syntax
(bit)
Notes

















Advanced




Generic MAC


header( ){


Flow ID
4
Flow Identifier


EH
1
Extended header group presence




indicator; When set to ‘1’, this




field indicates that an Extended




Header group is present following




this GMH.


Length
11
This field indicates the length in




bytes of MAC PDU including the AGMH




and extended header if present. EH is




set to ‘1’, this represent the 11




LSBs of 14 bit MAC PDU length




otherwise it represents the 11 bit




MAC PDU length.


}









Referring to Table 1, an AGMH includes a flow identifier (Flow ID) field having a flow identifier for identifying a service flow carrying MAC PDU using the corresponding AGMH from other service flows, an extended header presence indicator field (EH presence indicator) indicating whether an extended header of the corresponding MAC PDU is present, and a length field (Length) including length information of the corresponding MAC PDU.
When the extended header presence indicator field is set to ‘1’, this field indicates that at least one extended header is present at the MAC PDU. If the corresponding field is set to ‘0’, this field indicates that the extended header is not present. The length field (Length) indicates length information of the MAC PDU including the extended header if the extended header is present. The length field is represented in bytes. And, 11 bits are allocated to the length field. When the EH field is set to ‘1’, the length field represents the 11 LSBs of 14 bit MAC PDU length otherwise it represents the 11 bit MAC PDU length.
The short-packet MAC header (SPMH) is generated to have a size equal to or smaller than a predetermined size with predetermined periodicity like VoIP. And, the compact MAC header is usable if an application, to which ARQ (automatic retransmission request) is not applied, is supported.
Table 2 shows one example of a format of SPMH used in a wireless communication system based on IEEE 802.16 system.











TABLE 2








Size




Syntax
(bit)
Notes









Short-





packet



MAC



header( ){



EH
1
Extended header presence indicator; When





set to ‘1’, this field indicates that an





Extended Header is present following





this SPMH.



Length
7
This field indicates the length in bytes





of MAC PDU including the SPMH and





extended header if present.



}










Referring to Table 2, a SPMH includes an extended header presence indication field indicating whether an extended header is present and a length field indicating a length of MAC PDU including a SPMH.
Since the SPMH is a header that is used at a resource allocated location, which was already negotiated between a base station and a mobile station, for such resource allocation as persistent resource allocation and group resource allocation, a receiving side is able to identify the SPMH at the corresponding location despite that a flow identifier is not included. Unlike the AGMH, the SPMH does not include a field (Flow ID) including a flow identifier.
Since the persistent resource allocation or the group resource allocation is used as a resource allocation scheme for such a periodic and short packet as VoIP, a length of the SPMH can be implemented within a 7-bit range according to a VoIP packet size. Therefore, the compact MAC head, as exemplarily shown in Table 2, can have a size of 1 byte by allocating 1 bit and 7 bits to the extended header presence indicator field and the length field, respectively.
Meanwhile, a MAC PDU can be accompanied by at least one extended header according to property of information to be carried on the corresponding MAC PDU, a transmission scheme applied to the corresponding MAC PDU, or the like. The extended header is inserted right behind the MAC header. In case that a corresponding MAC PDU includes a payload, an extended header is inserted in front of the payload.
The extended header is a subheader inserted behind a MAC header in MAC PDU. Using an extended header presence indicator field of an AGMH or a SPMH, a receiving side can be informed whether the header is included in the MAC PDU. Yet, a MAC signaling header is not companied by an extended header.
Table 3 shows one example of a generic extended header used in a wireless communication system based on IEEE 802.16 system.









TABLE 3






Size



Syntax
(bit)
Notes







Extended




Header( ){


LAST
1
Last Extended Header indicator:




0 = one or more extended header flows




the current extended header unless




specified otherwise;




1 = this extended header is the last




extended header unless specified




otherwise


Type
TBD
Type of extended header


Body
Variable
Type dependent content


Contents


}









Referring to Table 3, an extended header includes an extended header presence indicator field (LAST) indicating whether at least one or more other extended headers are present behind the corresponding extended header, an extended header type field (Type) indicating a type of the corresponding extended header and an extended header body field (Body Contents) including at least one field having informations relevant to the extended header indicated by the extended header type field.
When 1 bit is allocated to the extended header indicator field (LAST), for example, if the corresponding field is set to 0, it indicates that the at least one or more other extended headers are present behind the current extended header. If the corresponding field is set to 1, it is able to indicate that the current extended header is the extended header included last in the corresponding MAC PDU.
In the extended header body field (Body Contents), the included information and a length of the body field are determined according to an extended header type indicated by the extended header type field (Type).
The extended header types are described with reference to Table 4 as follows.
Table 4 shows types of a generic extended header used in a wireless communication system based on IEEE 802.16 system.








TABLE 4





Extended header



type
Notes







Fragmentation and
This extended header is used in applying


Packing Extended
fragmentation, packing or sequence number


Header
to MAC PDU accompanied by a payload for a



single transport connection.


MAC Control
This extended header is used when MAC PDU


Extended Header
includes a payload for a control



connection.


Multiplexing
This extended header is used when a


Extended Header
payload for multiplexing association



related to the same SA (security



association) multiplexed in the same MAC



PDU is included.


Message ACK
This extended header is used for a base


Extended Header
station or a mobile station to indicate



acknowledgement of a MAC control message.


Sleep Control
This extended header is used for a base


Extended Header
station or a mobile station to deliver



control signaling related to a sleep



cycle operation.


Correlation
This extended header is used by a mobile


Matrix Feedback
station in response to feedback polling


Extended Header
A-MAP IE for requesting a quantized



transport correlation matrix when a base



station uses 2 or 4 transmitting



antennas.


MIMO Feedback
This extended header is used by a mobile


Extended Header
station in response to feedback polling



A-MAP IE fore requesting a feedback of



broadband or subband information.


Piggybacked
This extended header is used when a


Bandwidth Request
mobile station requests a piggybacked


Extended Header
bandwidth for at least one flow.


MAC PDU Length
This extended header is added to a


Extended Header
corresponding MAC PDU if a MAC PDU length



is equal to or greater than 2,047 bytes.


ARQ Feedback
This extended header is used when an ARQ


Extended Header
receiving part transmits feedback



information.









Regarding a plurality of the extended headers described with reference to Table 4, if a MAC PDU accompanied by a payload for a single transport connection is going to be fragmented, packed or ARQ-applied, FPEH is present at the corresponding MAC PDU. In doing so, an AGMH is used as a MAC header. Although fragmentation, packing, ARQ or the like is not applied, in that HARQ reordering is applied to such a small data packet as VoIP, MAC PDU can be accompanied by FPEH to include sequence number information on a packet to retransmit. In this case, a SPMH is used as a MAC header.
Table 5 shows one example of a fragmentation & packing extended header (FPEH) format used in a wireless communication system based on IEEE 802.16 system. And, fields included this format are described with reference to Table 5 as follows.









TABLE 5






Size



Syntax
(bit)
Notes

















FPEH( ){




RI (Rearrangement
1
This field includes ARQ rearrangement


header Indicator)

indicator.




‘0’ bit setting - Not indicate ARQ




rearrangement




‘1’ bit setting - Indicate ARQ




rearrangement


SN(Sequence
10
‘SN’ is maintained by connection unit.


Number)

Regarding non-ARQ connection, ‘SN’




indicates a sequence number of MAC




PDU containing a payload and a value




of the SN is incremented per MAC




PDU by 1.




Regarding ARQ connection, ‘SN’




indicates an ARQ block sequence




number.


FC (fragment
2
This field includes information on


Control)

fragmentation control


AFI (ARQ Feedback
1
This field includes ARQ feedback


IE)

information element (IE) indicator.




‘0’ bit setting: ARQ feedback IE is not




included in MAC PDU




‘1’ bit setting: ARQ feedback IE is




present behind FPEH


AFP (ARQ Feedback
1
This field includes ARQ feedback poll


Poll)

indicator.




‘0’ bit setting: ARQ feedback poll is




not included




‘1’ bit setting: ARQ feedback poll




relevant to a connection indicated by a




generic MAC header (GMH) is included


If(RI=1){


LSI (Last ARQ
1
Last ARQ subblock indicator


Subblock

‘0’ bit setting: Last subblock in


Indicator)

single ARQ block not included in a




corresponding MAC PDU is indicated




‘1’ bit setting: Single ARQ block




included in a corresponding MAC PDU


SSN (Sub-SN)
TBD
Sub-sequence number of 1st ARQ




subblock


}


Do{


End
1
Indication of more information




‘0’ bit setting: ‘Length’ field and




other ‘End’ field are further included




‘1’ bit setting: ‘Length’ field and




other ‘End’ field are not further




included


If(End=0){


Length
11
This field indicates the length of SDU




or SDU fragment


}


while (!End)


Reserved
variable
}


}









Referring to Table 5, a sequence number field (SN) included in FPEH indicates a sequence number of MAC PDU accompanied by a payload in case that the FPEH is not used for ARQ connection. The sequence number field (SN) is incremented by 1 for each MAC PDU. In case that the FPEH is used for the ARQ connection, the sequence number field is set to a prescribed value that indicates a sequence number of an ARQ block.
If the rearrangement header identifier field (RI) in the FPEH is set to 0 and the end field (End) indicating whether more information is included is set to 0, the fragmentation & packing extended header has a length of at least 2 bytes. In case of attempting to transmit data, the FPEH can present at a MAC PDU including a generic MAC header and a SPMH for HARQ reordering of VoIP packet.
In this case, SDU including a SPMH is used for such a periodically transmitted small packet as VoIP packet and the like. In this case, fragmentation, packing ARQ or the like is not performed on such a packet as VoIP and the FPEH uses the SN field only for HARQ reordering. Since the VoIP packet is generated to have a size smaller than that of other data with a prescribed periodicity, it is not necessary to allocate a considerable bit size to the SN field. Even if the FPEH of a minimum size (e.g., 2 bytes) is added to a VoIP packet including a SPMH, a size of the header becomes 3 bytes to result in unnecessary resource waste in VoIP packet transmission.
As mentioned in the foregoing description, a SPMH is used at a resource allocated location previously negotiated between a base station and a mobile station and does not include a field Flow ID to reduce a transmission overhead. Occasionally, when a base station or a mobile station receives a MAC PDU including a SPMH, it is necessary to perform a flow mapping process. For instance, in case of using a multiple persistent allocation (PA) or a group resource allocation, a base/mobile station should perform mapping on a corresponding flow in each resource allocation to be aware that each resource allocation is mapped to which service. In case of receiving a SPMH not including the field Flow ID at each corresponding location, the base/mobile station should perform a flow mapping process to increase a processing overhead.
Therefore, the present invention intends to propose a method of transmitting a signal using an efficient SPMH structure or format usable in transmitting such a small packet transmitted with a prescribed periodicity as a VoIP packet. And, the present invention also intends to propose a method of providing a service through a step of negotiating a MAC header type between a base station and a mobile station.
FIG. 6 is a diagram for one example of a SPMH structure according to one embodiment of the present invention.
In the following disclosure including FIG. 6, a single scale mark of a block representing a MAC PDU structure indicates 1 bit and a horizontal row indicates 1 byte. Moreover, bits are arranged downward in order from a most significant bit (MSB) to a least significant bit.
Referring to FIG. 6, a SPMH according to one embodiment of the present invention includes a flow identifier (Flow ID) field 601 having an identifier of a service flow, an extended header group presence indicator (EH) field 602 indicating whether an extended header group comprising at least one extended header is present behind the SPMH immediately, a length (Length) field 603 having length information of a corresponding MAC PDU, and a sequence number (SN) field 604 indicating a sequence number. The respective fields are schematically described with reference to Table 6 as follows.
Table 6 shows one example of a SPMH format according to one embodiment of the present invention.









TABLE 6






Size



Syntax
(bit)
Notes







Short-packet




MAC


Header( ){


Flow ID
4
Flow Identifier


EH
1
Extended Header group presence




indicator


Length
7
This field indicates the length in




bytes of MAC PDU including the SPMH




and extended header if present.


Sequence
4
This field indicates a MAC PDU


Number(SN)

payload sequence number incremented




by one for each MAC PDU


}









Referring to FIG. 6 and Table 6, a SPMH according to one embodiment of the present invention includes a 4-bit flow identifier field (Flow ID), a 1-bit extended header presence indicator field (EH), a 7-bit length field (Length) capable of supporting 127-byte MAC PDU, and a 4-bit sequence number field (SN). In this case, a size of the SPMH can be implemented with 2 bytes.
The flow identifier (FID) field 601 includes identification information of a service flow used by the corresponding SPMH.
The sequence number (SN) field 604 indicates sequence number information corresponding to a payload of the MAC PDU. In particular, since the SPMH is used in transmitting such a small packet generated with prescribed periodicity as VoIP packet, it is able to apply HARQ to an error check instead of applying ARQ thereto. Therefore, unlike the sequence number field included in the above FPEH described with reference to Table 5, the sequence number field of the SPMH includes a sequence number of the MAC PDU accompanied by the payload in case of not applying the ARQ. In this case, the bit value, to which the sequence number field is set, is incremented by 1 for each MAC PDU.
The SN field of the SPMH is used for HARQ reordering. If a maximum HARQ retransmission count in the IEEE 802.16m system is basically 4 and a maximum interval between retransmitted HARQs is 2 frames, a maximum time taken for the HARQ retransmissions is 8 frames in general. Assuming that the generation periodicity of VoIP packet is minimum 2 frames, when a 4-bit sequence number is used, it is less probable that the HARQ retransmission is not completed within 32 frames.
Therefore, a SPMH according to one embodiment of the present invention is able to simplify a size of the SPMH including a sequence number field by small bit allocation in a manner of allocating 4 bits to the sequence number field rather than allocating 10 bits to a sequence number field of FPEH.
In case of applying HARQ to a corresponding MAC PDU, the MAC PDU which includes SPMH may not be accompanied by FPEH. Therefore, it is able to reduce a size of over head of a MAC header into minimum 2 bytes, as shown in FIG. 6. In this case, it is able to use the extended header group presence indicator field 602 to indicate whether an extended header is present or not.
Thus, in case that a MAC PDU is transmitted using a SPMH according to one embodiment of the present invention or the AGMH described with reference to Table 1, a base station and a mobile station is able to perform negotiation about a of a MAC header type prior to MAC PDU transmission.
In particular, according to another embodiment of the present invention, a base station and a mobile station is able to previously negotiate to use either an AGMH or a SPMH according to a type or property of a packet to transmit, information to transmit and a transmission scheme used for packet transmission. This negotiation procedure can be performed via a MAC control message between a base station and a mobile station. In this case, MAC control messages available for the negotiation procedure include a dynamic service addition request/response message (e.g. Advanced Air Interface_Dynamic Service Addition-Request/Response: AAI_DSA-REQ/RSP), an advanced air interface dynamic service change request/response message (Advanced Air Interface Dynamic Service Change-Request/Response: AAI_DSC-REQ/RSP) and the like for example
In the following description, another embodiment of the present invention is explained on the assumption that a information on a MAC header type is shared using a dynamic service addition request/response message between a base station and a mobile station.
FIG. 7 is a diagram for one example of a process for a mobile station to perform a service connection for MAC PDU transmission to a base station according to another embodiment of the present invention.
Referring to FIG. 7, a mobile station (AMS) sends AAI_DSA-REQ to a base station to create a new service flow and a corresponding connection [S701].
In this case, the AAI_DSA-REQ sent to request the dynamic service flow generation can include parameters shown in Table 7 for example.










TABLE 7







Parameters in




AAI_DSA-REQ
Notes









Control Message Type
Type information of AAI_DSA-REQ




message



Service Flow parameters
Service flow parameters for




specifying traffic properties and




scheduling requirements of




service flow (cf. Table 8)



CS parameter encodings
This field includes a parameter




specified to a convergence




sublayer in a corresponding




service flow.



SCID
Sleep cycle setting change




(included in AAI_DSA-REQ sent by




a base station or AAI_DSA-RSP




sent by a base station in




response to a request made by a




mobile station)



Predefined BR Index
Index information used for a




preset bandwidth request




procedure (included in AAI_DSA-




REQ sent by a base station or




AAI_DSA-RSP sent by a base




station in response to a request




made by a mobile station)



E-MBS service
Parameter for requesting a




presence or non-presence of a




multicast/broadcast service (yet,




this field is included in




AAI_DSA-REQ sent by a mobile




station only)










Referring to Table 7, various parameters for a dynamic service addition request are included in AAI_DSA-REQ. And, MAC header type information related to one embodiment of the present invention can be included in a service flow parameter among the various parameters.
Table 8 shows various parameters included in service flow parameters. In addition, the service addition request/response (AAI_DSA-REQ/RSP) messages can further include various service flow parameters omitted from Table 8.









TABLE 8






Size



Fields
(bits)
Description







Flow ID
4
Service flow ID information


UL/DL
1
This field includes an indicator


Indicator

indicating whether a link related to




corresponding parameter is uplink or




downlink


. . .
. . .
. . .


MAC Header
1
This field indicates whether AGMH or


Type

SPMH is present at the start of MAC




PDUs of a corresponding service flow.




0 = AGMH




1 = SPMH









Referring to Table 8, a service flow parameter can include an identifier (Flow ID) for a service flow to be used in the future, an uplink/downlink indicator (UL/DL Indicator) indicating that corresponding parameters are used in either uplink or downlink.
The flow identifier specifies a connection which is associated with a service flow to the mobile station.
In case that a base station (ABS) sends AAI_DSA-REQ message (i.e. ABS initiated), a flow identifier can be included in the AAI_DSA-REQ. In other case that a mobile station (AMS) sends AAI_DSA-REQ (i.e., AMS initiated), as shown in FIG. 7, a flow identifier can be included in AAI_DSA-RSP message sent by a base station in response to the AAI_DSA-REQ message.
A MAC header type parameter indicates which one of an AGMH and a SPMH is used for a corresponding MAC PDU of the service flow. For instance, when 1 bit is allocated to the MAC Header Type parameter, if the MAC header type parameter is set to ‘0’, it indicates that an AGMH is used. If the MAC header type parameter is set to ‘1’, it indicates that a SPMH is used.
Yet, the meaning indicated according to the bit setting at the MAC header type parameter is just one example for describing the present invention. Regarding the type information according to the bit value setting corresponding to the MAC header type field, the meanings indicated by the ‘0’ and ‘1’ bit settings can be switched to each other.
Referring now to FIG. 7, the mobile station is able to send AAI_DSA-REQ message including a parameter (MAC Header Type=1) about a MAC header type for specifying a use of a SPMH to the base station in order to transmit such a small packet generated with prescribed periodicity as VoIP. In this case, the AAI_DSA-REQ can further include the UL/DL indicator indicating parameters are for an uplink.
Having received the AAI_DSA-REQ message, the base station sends
AAI_DSA-RSP message to the mobile station in response to the received AAI_DSA-REQ message [S702].
In particular, parameters included in the AAI_DSA-RSP are described with reference to Table 9 as follows.








TABLE 9





Parameters in



AAI_DSA-RSP
Notes







Control Message Type
Type information of AAI_DSA- RSP



message


Confirmation Code (CC)
Confirmation code for the



corresponding AAI_DSA- REQ


Service Flow parameters
Service flow parameters for



specifying traffic properties and



scheduling requirements of



service flow (cf. Table 8)


CS parameter encodings
This field includes a parameter



specified to a convergence



sublayer in a corresponding



service flow.


SCID
Sleep cycle setting change



(included in AAI_DSA-REQ sent by



a base station or AAI_DSA-RSP



sent by a base station in



response to a request made by a



mobile station)


Predefined BR Index
Index information used for a



preset bandwidth request



procedure (included in AAI_DSA-



REQ sent by a base station or



AAI_DSA-RSP sent by a base



station in response to a request



made by a mobile station)


FID (Flow ID)
This field indicates Flow ID



information on a transport



connection included if a service



flow is successfully added.


QoS parameters
QoS parameter relevant to service



classification


E-MBS service/E-MBS Zone
This field indicates ID


ID/E-MBS service Flow
information of E-MBS zone and


parameters
service flow parameter about E-



MBS if E-MBS is supported.









Referring to Table 9, AAI_DSA-RSP message includes prescribed parameters. And, a type of each of the included parameters is determined according to a transmitting subject. AAI_DSA-RSP type information, a confirmation code for AAI_DSA-REQ, a service flow parameter and a parameter specified to a CS in a corresponding service flow may be included in the AAI_DSA-RSP message sent by a base station or a mobile station.
According to the sent AAI_DSA-REQ message, in case that a service flow generation is successfully performed, parameters relevant to SCID, Predefined BR index, FID, E-MBS service and the like can be further included in the AAI_DSA-RSP message.
The service flow parameter is further included in the AAI_DSA-RSP message as well. Since the AAI_DSA-RSP message includes the same information described with reference to Table 8, the redundant description shall be omitted from the following description. Yet, regarding information on a MAC header type, a MAC header type parameter identical to that included in the AAI_DSA-REQ message or MAC header type information arbitrarily determined by the base station can be included in the AAI_DSA-RSP message sent by the base station in response to a request made by the mobile station. In case that the mobile station sends AAI_DSA-RSP message in response to the AAI_DSA-REQ message sent by the base station. The MAC header type parameter can be also included in the AAI_DSA-RSP message.
In FIG. 7, since the base station sends the MAC header type parameter indicating the use of the SPMH via the AAI_DSA-RSP message in the step S702, it can be regarded as performing the negotiation on the SPMH use between the base station and the mobile station.
Having received the AAI_DSA-RSP, the mobile station sends AAI_DSA-ACK indicating acknowledgement of the response message to the base station [S703]. Thus, the service generation request procedure is completed to use the SPMH in uplink and an uplink service connection is established.
Afterwards, the mobile station is able to communicate (i.e., transmitting and/or receiving) with the base station using MAC PDUs of the service flow. In this case, the MAC PDUs comprising a MAC header indicated by the MAC header type field (i.e. SPMH) [S704]. In doing so, the SPMH used by the mobile station can include the generic SPMH described with reference to Table 2 or the SPMH configured according to one embodiment of the present invention (See, FIG. 6).
FIG. 8 is a diagram for one example of a process for a base station to perform a service connection procedure for MAC PDU transmission to a mobile station according to another embodiment of the present invention.
Referring to FIG. 8, in order to perform a downlink data transmission, a base station (ABS) sends AAI_DSA-REQ message requesting a new service flow generation to a mobile station (AMS) [S801].
In the AAI_DSA-REQ (ABS-initiated AAI_DSA-REQ) initiated by the base station, the QoS parameter and FID on the corresponding service flow and the like, which are described with reference to Table 9, can be included. Moreover, various parameters described with reference to Table 7 and Table 9 are included in the AAI_DSA-REQ message. And, a MAC header type parameter to be used can be included in a MAC PDU to be transmitted. For instance, in case that the base station attempts to transmit such a packet as VoIP to the mobile station, a MAC header type parameter is set to 1 bit and a field including a link indicator can be set to a bit for indicating ‘downlink’.
Having received the AAI_DSA-REQ message, the mobile station sends AAI_DSA-RSP message to the base station in response to the received AAI_DSA-REQ [S802].
Likewise, the AAI_DSA-RSP can include the former parameters described with reference to Table 9. Yet, the MAC header type parameter included in the AAI_DSA-RSP sent by the mobile station is set to indicate the same MAC header type included in the AAI_DSA-REQ.
The base station sends AAI_DSA-ACK for the AAI_DSA-RSP to the mobile station [S803], thereby establishing a downlink service connection using the SPMH.
Afterwards, the base station is able to communicate (i.e., transmitting and/or receiving) with the mobile station using MAC PDUs of the service flow. In this case, the MAC PDUs comprising a MAC header indicated by the MAC header type field (i.e. SPMH)[S804].
In doing so, the SPMH can be referenced to the generic compact MAC header described with reference to Table 2 or the SPMH configured according to one embodiment of the present invention (see, FIG. 6).
FIG. 9 and FIG. 10 are flowcharts other examples of a process for transmitting a signal according to one embodiment of the present invention. In particular, a process for transmitting a signal using an AGMH is shown.
FIG. 9 is a diagram for another example of a process for a mobile station (AMS) to perform a service connection for MAC PDU transmission to a base station (ABS) according to another embodiment of the present invention, which corresponds to the former signal transmitting process described with reference to FIG. 7. Specifically, steps S901 to S904 shown in FIG. 9 correspond to the former steps S701 to S704 shown in FIG. 7, respectively. Yet, a MAC header type parameter included in AAI_DSA-REQ/RSP messages of the step S901/S902 can be set to ‘0’ to indicate a use of an advanced generic MAC header (AGMH) according to the example shown in Table 4.
After a service connection has been established, a MAC PDU transmitted in uplink in the step S904 uses the generic MAC header (AGMH) exemplarily shown in Table 1 and is accompanied by the fragmentation & packing extended header (FPEH) described with reference to Table 5 for the VoIP packet transmission. In case that a fragmentation & packing extended header (FPEH) is present, an extended header presence indicator field of the AGMH can be set to ‘1’. Hence, the corresponding MAC PDU uses an AGMH of minimum 2 bytes and a MAC header of minimum 4 bytes in use of FPEH of minimum 2 bytes.
FIG. 10 is a diagram for another example of a process for a base station to perform a service connection for MAC PDU transmission to a mobile station according to another embodiment of the present invention, which corresponds to the former signal transmitting process described with reference to FIG. 8. Specifically, steps S1001 to S1004 shown in FIG. 10 correspond to the former steps S801 to S804 shown in FIG. 8, respectively. And, the description of a MAC header type parameter indicating a use of an AGMH is the same as described with reference to FIG. 9.
In case of using a SPMH or an AGMH according to one embodiment of the present invention, a mobile station receives a MAC PDU including the corresponding MAC header, identifies a connection which is associated with a service flow via ‘Flow ID’ included in AAI_DSA-REQ message, and then obtains MAC header information of the MAC header used by the corresponding service flow. Therefore, the mobile station confirms a MAC header used by a corresponding flow via ‘Flow ID’ of a MAC header included in a next-transmitted MAC PDU and is then able to perform a processing process on the corresponding MAC PDU.
Moreover, in case of using a SPMH in a prescribed length (e.g., 2 bytes) including a sequence number according to one embodiment of the present invention, as shown in FIG. 6, a separate FPEH needs not to be present. Therefore, it is able to reduce a MAC header overhead.
The MAC header type negotiation procedures performed via AAI_DSA-REQ/RSP in the embodiments of the present invention described with reference to FIGS. 7 to 10 are identically applicable to a procedure performed in case of changing a dynamic service flow. In this case, a base station and a mobile station enable indication information on a MAC header type to be included as a service flow parameter in the course of exchanging AAI_DSC-REQ/RSP messages.
Besides, a SPMH including a sequence number (SN) field according to one embodiment of the present invention can be implemented in various types within a prescribed length.
In the following description, one example of a transmitting device (or, transmitting end) for generating a MAC PDU including a MAC header (e.g. SPMH or AGMH) according to one of embodiments of the present invention is described with reference to FIG. 11 as follows.
FIG. 11 is a diagram for one example of a MAC PDU generating unit in a transmitting device according to another embodiment of the present invention. In particular, FIG. 11 shows a process for constructing MAC PDU used for ARQ connection, non-ARQ connection or control connection.
Referring to FIG. 11, a MAC PDU generating unit in a transmitting end can include a MAC control module 1101, a convergence sublayer 1102 and a MAC PDU generating module 1103.
MAC control messages generated from the MAC control module 1101 are fragmented into MAC PDU accompanied by a payload and can be then delivered to the MAC PDU generating module 1103. Moreover, control information required for generating a signaling header can be transmitted to the MAC PDU generating module 1103 as well.
The convergence sublayer 1102 performs a function of converting or mapping data, which is to be transmitted, to MAC SDU. In particular, the convergence sublayer 1102 classifies MAC SDUs into a MAC SDU to transmit and a transmitted MAC SDU. Once related to a specific MAC connection, at least one upper layer PDU should be compressed into a type of MAC SDU. This SDU to enter a network can be classified by the convergence sublayer 1102 into at least one set according to a prescribed mapping reference. The convergence sublayer is able to perform header compression on at least one header included in the generated MAC SDU. The convergence sublayer 1102 delivers the MAC SDU to transmit to the MAC PDU generating module 1103 and is able to provide information (e.g., length information, etc.) required for the header generation of the MAC PDU to transmit as well.
The at least one MAC SDU generated by the convergence sublayer 1102 is converted to a MAC PDU payload via fragmentation or packing. The converted at least one MAC PDU payload is then delivered to the MAC PDU generating module. In this case, the MAC PDU payload can be classified according to a case of applying ARQ or a case of not applying ARQ.
The MAC PDU generating module 1103 constructs MAC PDU including the MAC PDU payload delivered from the MAC control module 1101 or the convergence sublayer 1102 and is able to include a MAC header generating unit and a multiplexer. In this case, a MAC header generated by the MAC header generating unit can include at least one of a generic MAC header described with reference to Table 1, a SPMH described with reference to Table 2 and a SPMH described with reference to FIG. 6.
Meanwhile, the multiplexer generates and outputs MAC PDU by multiplexing the received MAC header and MAC SDUs received in order under the control of the header generating unit.
In doing so, the MAC PDU generating module 1103 is able to perform encryption on the MAC PDU. In particular, the MAC PDU generating module 1103 further attaches PN and ICV to the generated MAC PDU or is able to attach CRC to the generated MAC PDU.
Afterwards, the generated MAC PDU is generated into at least one contiguous MAC PDU, is delivered to a physical layer, and is then externally transmitted.
FIG. 12 is a block diagram for describing a mobile station and a base station according to a further embodiment of the present invention for performing the above described embodiments of the present invention.
First of all, a mobile station (AMS) works as a transmitting end in uplink and is able to work as a receiving end in downlink. A base station (ABS) works as a receiving end in uplink and is able to work as a transmitting end in downlink. In particular, each of the mobile station and the base station includes a transmitter and a receiver for transmission of information and/or data.
Each of the transmitting end and the receiving end can include a processor, a module, a part and/or a means for performing embodiments of the present invention. In particular, each of the transmitting end and the receiving end can include a module (means) for encrypting a message, a module for interpreting the encrypted message, an antenna for exchanging the message and the like.
Referring to FIG. 12, a left side indicates a configuration of a transmitting end, while a right side indicates a configuration of a receiving end. Each of the transmitting end and the receiving end includes an antenna, a receiving module 1210/1220, a processor 1230/1240, a transmitting module 1250/1260, and a memory 1270/1280.
The antenna includes a receiving antenna performing a function of receiving a radio signal externally and then delivering the received radio signal to the receiving module 1210/1220 and a transmitting antenna externally transmitting a signal generated from the transmitting module 1250/1260. In case that a multiple-antenna (MIMO) function is supported, at least two antennas can be provided.
The receiving module 1210/1220 reconstructs the radio signal received externally via the antenna into original data in a manner of performing decoding and demodulation on the received radio signal and is then able to deliver the reconstructed original data to the processor 1230/1240. Alternatively, the receiving module and the antenna can be represented as a receiving unit configured to receive a radio signal instead of being separated from each other, as shown in FIG. 12.
The processor 1230/1240 generally controls overall operations of the mobile/base station. In particular, the processor 1230/1240 is able to perform a control function for performing the above-described embodiments of the present invention, a MAC (medium access control) frame variable control function according to service characteristics and propagation environment, a handover function, an authentication function, an encryption function and the like.
The transmitting module 1250/1260 performs prescribed coding and modulation on a signal and/or data, which is scheduled by the processor 1230/1240 and will be then transmitted externally, and is then able to deliver the coded and modulated signal and/or data to the antenna. Alternatively, the transmitting module and the antenna can be represented as a transmitting unit configured to transmit a radio signal instead of being separated from each other, as shown in FIG. 12.
The memory 1270/1280 can store programs for processing and control of the processor 1230/1240 and is able to perform a function of temporarily storing input/output data (e.g., in case of the mobile station, UL grant allocated by the base station, system information, station identifier (STID), a flow identifier (FID), an action time, region allocation information, frame offset information, etc.). And, the memory 1270/1280 can include at least one of storage media including a flash memory, a hard disk, a multimedia card micro type memory, a memory card type memory (e.g., SD memory, XD memory, etc.), a RAM (random access memory), an SRAM (static random access memory), a ROM (read-only memory), an EEPROM (electrically erasable programmable read-only memory), a PROM (programmable read-only memory), a magnetic memory, a magnetic disk, an optical disk and the like.
The processor 1230 of the transmitting end performs overall control operations on the transmitting end and is able to include a MAC control module 1231 configured to control a MAC layer for a service connection to the receiving end and the like and a MAC PDU generating module 1232 configured to generate MAC PDU.
The MAC control module 1231 generates a MAC control message for controlling a MAC layer and then controls the MAC layer through a relevant message exchange with the receiving end. In doing so, as mentioned in the foregoing description with reference to FIGS. 7 to 10, the MAC control module 1231 is able to generate a service connection request message including a parameter of a MAC header type to be used for a corresponding service flow in case of a service connection establishment. In this case, the parameter of the MAC header type is determined by the MAC control module 1231 or can be determined based on information received from the MAC PDU generating module 1232. Moreover, since the MAC PDU generating module 1232 corresponds to the MAC PDU generating unit described with reference to FIG. 11, the redundant description shall be omitted from the following description.
The receiving end receives a service connection request message sent by the transmitting end via the receiving module 1220 and then forwards the received message to the processor 1240.
The processor 1240 of the receiving end performs overall control operations on the receiving end, determines whether to connect a service to the transmitting end in response to the received service connection request message, and then generates a response message in response to the received request message. Likewise, the processor 1240 is able to perform the procedures according to the embodiments of the present invention described with reference to FIGS. 7 to 10.
Moreover, the processor 1240 is able to include a signal processing module 1241 configured to perform processing on a signal received from the transmitting end. In this case, the signal processing module 1241 is able to perform a signal processing procedure on a received MAC PDU according to a MAC header type of each of the embodiments of the present invention.
A mobile station used for embodiments of the present invention can include a low-power RF/IF (radio frequency/intermediate frequency) module as well as the MAC PDU generating unit. And, the mobile station can include means, modules, parts and/or the like for performing 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 characteristic and electric wave environment, a handover function, an authentication and encryption function, a packet modulation/demodulation function for data transmission, a fast packet channel coding function, a real-time modem control function, and the like.
A base station is able to transmit data received from an upper layer to a mobile station. The base station can include a low-power RF/IF (radio frequency/intermediate frequency) module. And, the base station can include means, modules, parts and/or the like for performing a controller function for performing the above-described embodiments of the present invention, an OFDMA (orthogonal frequency division multiple access) packet scheduling, TDD (time division duplex) packet scheduling and channel multiplexing function, a MAC (medium access control) frame variable control function according to a service characteristic and electric wave environment, a fast traffic real-time control function, a handover function, an authentication and encryption function, a packet modulation/demodulation function for data transmission, a fast packet channel coding function, a real-time modem control function, and the like.
Industrial Applicability
Accordingly, the present invention is applicable to various wireless communication systems.
While the present invention has been described and illustrated herein with reference to the preferred embodiments thereof, it will be apparent to those skilled in the art that various modifications and variations can be made therein without departing from the spirit and scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention that come within the scope of the appended claims and their equivalents. And, it is apparently understood that an embodiment is configured by combining claims failing to have relation of explicit citation in the appended claims together or can be included as new claims by amendment after filing an application.

## Claims

1. A method for communicating in a wireless access system using a medium access control protocol data unit (MAC PDU), the method comprising:
receiving, by a mobile station (MS) from a base station (BS), a dynamic service addition request (AAI_DSA-REQ) message requesting to create a service flow, wherein the AAI_DSA-REQ message comprises a first MAC header type parameter indicating a type of a MAC header to be included in the MAC PDU of the service flow and a flow identifier (FID) identifying a connection associated with the service flow;
transmitting, by the MS to the BS, a dynamic service addition response (AAI_DSA-RSP) message in response to the AAI_DSA-REQ message, wherein the AAI_DSA-RSP message comprises a second MAC header type parameter indicating the type of a MAC header to be included in the MAC PDU of the service flow; and
communicating with the BS using the MAC PDU comprising the MAC header indicated by the second MAC header type parameter;
wherein the second MAC header type parameter indicates one of a generic MAC header (GMH) for general data packet transmission and a short-packet MAC header (SPMH) for small data packet transmission and a non-ARQ connection, and
wherein the SPMH consists of the flow identifier (FID) field identifying the connection used for the transmission of the MAC PDU, an extended header group presence indicator (EH) field indicating whether an extended header group is present following the SPMH, a length field indicating a length in bytes of the MAC PDU including the SPMH and an extended header if present, and a sequence number (SN) field indicating a payload sequence number of the MAC PDU,
wherein the SN field increments by one for each MAC PDU, and
wherein a size of the FID field is 4 bits, a size of the EH field is 1 bit, a size of the length field is 7 bits, and a size of the SN field is 4 bits, and
wherein a total size of the SPMH is 2 bytes.

2. The method according to the claim 1, wherein the AAI_DSA-REQ message further comprises service flow parameters specifying traffic characteristics and scheduling requirements of the service flow and convergence sublayer parameters encodings specifying convergence sublayer specific parameters.

3. The method according to the claim 2, wherein the service flow parameters comprise a link indicator indicating whether parameters for the MAC PDU transmission are for an uplink or a downlink.

4. The method according to claim 2, wherein the small data packet is a voice over internet protocol (VoIP) data packet which has a predetermined fixed size with a predetermined periodicity.

5. The method according to the claim 4, wherein the GMH consists of the flow identifier (FID) field, an extended header group presence indicator (EH) field, and a length field.

6. The method according to claim 5, wherein the FID field identifies the connection used for the transmission of the MAC PDU;
the EH field indicates whether an extended header group is present following the GMH; and
the length field indicates a length in bytes of the MAC PDU including the GMH and an extended header if present.

7. The method according to claim 1, wherein the SN field is used for an HARQ (hybrid-automatic retransmission request) scheme.

8. A station for communicating in a wireless access system using a medium access control protocol data unit (MAC PDU), the station comprising:
a transmitter;
a receiver; and
a processor configured to generate the MAC PDU,
wherein the MAC PDU comprises a MAC header indicated by a MAC header type parameter determined during a dynamic service flow creation procedure,
wherein the MAC header type parameter indicates one of a generic MAC header (GMH) and a short-packet MAC header (SPMH),
wherein the SPMH consists of the flow identifier (FID) field identifying the connection used for the transmission of the MAC PDU, an extended header group presence indicator (EH) field indicating whether an extended header group is present following the SPMH, a length field indicating a length in bytes of the MAC PDU including the SPMH and an extended header if present, and a sequence number (SN) field indicating a payload sequence number of the MAC PDU,
wherein the SN field increments by one for each MAC PDU,
wherein a size of the FID field is 4 bits, a size of the EH field is 1 bit, a size of the length field is 7 bits, and a size of the SN field is 4 bits, and
wherein a total size of the SPMH is 2 bytes.

9. The station according to claim 8, wherein the processor comprises a convergence sublayer, a service data unit (SDU) fragmentation or packing function unit, and a MAC PDU formation module which are used for generating the MAC PDU.

10. The station according to claim 8, wherein the dynamic service flow creation procedure is performed by exchanging a dynamic service addition request (AAI_DSA-REQ) message and a dynamic service addition response (AAI_DSA-RSP) message.

11. The station according to claim 10, wherein the station communicates with another station using the MAC PDU comprising the MAC header indicated by the MAC header type parameter,
wherein the MAC PDU is constructed by the MAC PDU generating unit, and
wherein the MAC header type parameter has 1 bit to indicate the type of the MAC header.

12. The station according to the claim 10, wherein the AAI_DSA-REQ message comprises service flow parameters specifying traffic characteristics and scheduling requirements of the service flow and convergence sublayer parameters encodings specifying convergence sublayer specific parameters, and
wherein the service flow parameters comprise a link indicator indicating whether parameters for the MAC PDU transmission is uplink or a downlink and the MAC header type parameter.

13. The station according to the claim 10, wherein the AAI_DSA-RSP message comprises service flow parameters specifying traffic characteristics and scheduling requirements of the service flow and convergence sublayer parameters encodings specifying convergence sublayer specific parameters, and
wherein the service flow parameters comprises a link indicator indicating whether parameters for the MAC PDU transmission is uplink or a downlink and the MAC header type parameter.

14. The station according to claim 10, wherein the small data packet is a voice over internet protocol (VoIP) data packet which has a predetermined fixed size with a predetermined periodicity.

15. The station according to the claim 14, wherein the GMH consists of the flow identifier (FID) field, an extended header group presence indicator (EH) field, a length field and a sequence number (SN) field.

16. The station according to claim 15, wherein the FID field identifies the connection used for the transmission of the MAC PDU;
the EH field indicates whether an extended header group is present following the GMH; and
the length field indicates a length in bytes of the MAC PDU including the GMH and an extended header if present.

17. The station according to claim 16, wherein the SN field is used for an HARQ (hybrid-automatic retransmission request) scheme.

18. The method according to claim 1, wherein the second MAC header type parameter has 1 bit to indicate the type of the MAC header.