Method and apparatus for generating acknowledgement frame

Provided are a method and an apparatus for generating an acknowledgement (ACK) frame. The method includes: receiving a data frame; first determining whether sub-frames included in the received data frame are coded in an unequal error protection (UEP) mode; and based on the determination of the first determining, generating the ACK frame including a first ACK field indicating reception of each of the sub-frames or second ACK field indicating reception of each first type bit and second type bit in the sub-frames.

BACKGROUND

The present invention relates to a method and an apparatus for generating an acknowledgement (ACK) frame in a wireless network environment, including a Wireless Personal Area Network (WPAN) and other types of wireless networks.

2. Description of Related Art

WPAN is a short distance area wireless network centered around an individual person's workspace. In the WPAN, devices in a piconet having a range of approximately 10 m communicate with each other using a time division multiple access (TDMA) method and form an ad-hoc network.

In order to provide the communication standard in the personal operating space, the IEEE 802.15 working group (WG) was formed. From among four task groups (TG) included in the IEEE 802.15 WG, the standardization of a High Rate (HR)-WPAN for high-speed data transmission has been completed.

In order to secure stable communication in such wireless network environment, an acknowledgment (ACK) frame is used. For example, when a transmitting device transmits a data frame to a receiving device and the receiving device receives the transmitted data frame, the receiving device transmits the ACK frame to the transmitting device.

In addition, when the data frame transmitted by the transmitting device is formed of a plurality of sub-frames, the receiving device transmits a block ACK frame with respect to each sub-frame to the transmitting device.

SUMMARY

According to an aspect of the present invention, there is provided a method of generating an acknowledgement (ACK) frame, the method including: receiving a data frame; first determining whether sub-frames included in the received data frame are coded in an unequal error protection (UEP) mode; and based on the determination of the first determining, generating the ACK frame including a first ACK field indicating reception of each of the sub-frames or a second ACK field indicating reception of each first type bit and second type bit in the sub-frames.

The method may further include: second determining whether a data insertion ACK request field for requesting the ACK frame including sub-frames or at least one MAC service data unit (MSDU) is included in the data frame, wherein in generating the ACK frame, the ACK frame further including the sub-frames or the at least one MSDU is selectively generated based on the determination of the second determining.

In generating the ACK frame, the ACK frame including a MAC header, a sub-header including the first ACK field, or the second ACK field, and a frame check sequence (FCS) field for detecting an error in the MAC header and the sub-header may be generated.

When it is determined that the sub-frames included in the data frame are not coded in the UEP mode, based on the determination of the first determining, information about reception of each sub-frame may be recorded to the first ACK field twice.

When it is determined that the data insertion ACK request field is included in the data frame based on the determination of the second determining, the ACK frame including the sub-frames or the at least one MSDU, a MAC sub-header, and the MAC header may be generated, the MAC sub-header including an UEP field indicating information relating to the UEP mode applied to the sub-frames or to the at least one MSDU, the first ACK field, or the second ACK field.

The UEP field may include an UEP enable field indicating whether the sub-frames or the at least one MSDU is coded in the UEP mode and an UEP modulation and coding scheme (MCS) field indicating a MCS applied to the sub-frames or to the at least one MSDU coded in the UEP mode.

The ACK frame may further include a physical (PHY) header including a modulation and coding scheme (MCS) field indicating a MCS applied to the sub-frames or to the at least one MSDU that are not coded in the UEP mode.

The data frame may include the sub-header including the sub-frames and information about the sub-frames, and the first determining is performed based on the sub-header.

The first type bits may be the most significant bits (MSB) in the sub-frames and the second type bits may be the least significant bits (LSB) in the sub-frames.

According to another aspect of the present invention, there is provided an apparatus for generating an acknowledgement (ACK) frame, the apparatus including: a receiver receiving a data frame; a first determination unit determining whether sub-frames included in the received data frame are coded in an unequal error protection (UEP) mode; and a frame generator generating the ACK frame including a first ACK field indicating reception of each of the sub-frames or a second ACK field indicating reception of each first type bit and second type bit in the sub-frames, based on the determination of the first determination unit.

The apparatus may further include a second determination unit determining whether a data insertion ACK request field for requesting the ACK frame including sub-frames or at least one MAC service data unit (MSDU) is included in the data frame, wherein the frame generator selectively generates the ACK frame, the ACK frame further including the sub-frames or the at least one MSDU, based on the determination of the second determination unit.

According to another aspect of the present invention, there is provided a computer readable recording medium having recorded thereon a computer program for executing the method of generating an acknowledgement (ACK) frame, the method including: receiving a data frame; first determining whether sub-frames included in the received data frame are coded in an unequal error protection (UEP) mode; and based on the determination of the first determining, generating the ACK frame including a first ACK field indicating reception of each of the sub-frames or a second ACK field indicating reception of each first type bit and second type bit in the sub-frames.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, the present invention will be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown.

FIG. 1is a flowchart illustrating a method of generating an acknowledgement (ACK) frame, according to an embodiment of the present invention.

In operation110, a data frame can be received.

Whether sub-frames included in the received data frame may be coded in an unequal error protection (UEP) mode. Here, a sub-header indicating information about the sub-frames may be further included in the received data frame. Thus, whether the sub-frames included in the data frame are coded in an UEP mode can be determined based on the sub-header in operation120.

In operation130, the ACK frame including a first ACK field or a second ACK field can be generated based on the determination in the operation120. The first ACK field may indicate reception of each of the sub-frames and the second ACK fields may indicate reception of each first type bit and second type bit in the sub-frames.

More specifically, if it is determined that the sub-frames of the data frame are coded by an EEP mode, instead of an UEP mode, the ACK frame can be generated to include the first ACK field and bits forming the first ACK field may be used to indicate reception of each sub-frame. For example, when the first ACK field is formed of 256 bits, the reception for each of the 256 sub-frames may be indicated.

However, when it is determined that the sub-frames of the data frame is coded by an UEP mode, the data frame may be formed of the first type bits and the second type bits and the ACK frame may be generated to include the second ACK field for indicating the reception of the two types of bits.

For example, the second ACK field may use 512 bits for indicating reception of each of the first type bits and the second type bits in 256 sub-frames. Here, 256 bits may be used as the second ACK field for the first type bits and the rest 256 bits may be used as the second ACK field for the second type bits.

Here, according to another embodiment, the first type bits may be the most significant bits (MSB) in the sub-frames and the second type bits may be the least significant bits (LSB) in the sub-frames. However, the present invention is not limited thereto, and thus, for example, in case of RGB data, the upper four bits of 1 byte have more important information than the lower four bits of 1 byte. As such, the upper four bits that have more important information than the lower four bits are the MSB and the lower four bits are the LSB. However, which upper bits in 1 byte become the MSB may differ according to a data type and embodiment and the rest of the bits, except for the MSB, become the LSB in 1 byte.

Configuration and generation of the data frame according to an exemplary embodiment of the present invention can be implemented in a variety of manners, including the other wireless or wired communications environment, without departing from the scope of the present invention.

FIG. 2is a flowchart illustrating a method of generating an ACK frame, according to another embodiment of the present invention.

In operation210, a data frame can be received.

In operation220, it can be determined whether sub-frames included in the received data frame are coded in an UEP mode.

In operation230, based on the result of the determination in operation220, when it is determined that the sub-frames of the data frame are not coded in an UEP mode, it can be determined whether a data insertion ACK request field for requesting the ACK frame including sub-frames or at least one MAC service data unit (MSDU) is included in the data frame.

Here, the data insertion ACK request field may be included in a MAC header of the received data frame and the MAC header may further include a block ACK request field for requesting the ACK frame in a block ACK form.

In operation232, when it is determined in operation230that the data insertion ACK request field is included in the data frame, the ACK frame including the sub-frames and the first ACK field can be generated.

Here, instead of the sub-frames, at least one MSDU may be included in the ACK frame.

In operation234, when it is determined in operation230that the data insertion ACK request field is not included in the data frame, the ACK frame only including the first ACK field can be generated.

In operation240, based on the result of the determination in operation220, when it is determined that the sub-frames of the data frame are coded in an UEP mode, whether the data insertion ACK request field is included in the data frame can be determined.

In operation242, when it is determined in operation240that the data insertion ACK request field is included in the data frame, the ACK frame including the sub-frames and the second ACK field may be generated. Here, instead of the sub-frames, at least one MSDU may be included in the ACK frame.

In operation244, when it is determined in operation240that the data insertion ACK request field is not included in the data frame, the ACK frame only including the second ACK field can be generated.

FIG. 3is a diagram illustrating a configuration of the ACK frame according to an embodiment of the present invention.

Referring toFIG. 3, the ACK frame, according to an exemplary embodiment, can include fields of a MAC header310that is used in a MAC layer, a sub-header320, and a frame check sequence (FCS)330.

The sub-header320may include first ACK fields322and324represented by ACK/NACK bitmap or include second ACK fields322and324represented by MSB ACK bitmap and LSB ACK bitmap. More specifically, when the sub-frames included in the received data frame are coded in an EEP mode, the sub-header320can include the first ACK fields322and324. Accordingly, the ACK/NACK bitmap indicating reception of each of the sub-frames is recorded to the first ACK field322and the ACK/NACK bitmap recorded to the first ACK field322is recorded once more to the first ACK field324.

However, when the sub-frames included in the received data frame are coded in an UEP mode, the sub-header320can have the second ACK fields322and324. Accordingly, the MSB ACK bitmap indicating reception of the MSB in each of the sub-frames can be recorded to the second ACK field322and the LSB ACK bitmap indicating reception of the LSB in each of the sub-frames can be recorded to the second ACK field324.

As such, when the ACK frame according to the exemplary embodiment is used, the device, which receives the data frame, may independently indicate the reception of the MSB and LSB in the sub-frames of the received data frame.

Meanwhile, according to other exemplary embodiments, information about reception of one sub-frame may be recorded twice, as illustrated inFIG. 3, because the same bits are to be used when indicating reception of the sub-frames coded in an EEP mode, while 2 bits are used to indicate reception of one sub-frame when the sub-frames are coded in an UEP mode.

However, the ACK frame according to the present invention is not limited thereto and thus information about reception of one sub-frame may be recorded to the first ACK field322only once.

Also, the FCS330is a field for detecting an error in the MAC header310and the sub-header320

FIG. 4is a diagram illustrating a configuration of an ACK frame according to another embodiment of the present invention.

Referring toFIG. 4, the ACK frame may include MSDUs. However, the ACK frame may include sub-frames, instead of MSDUs.

The physical (PHY) header410may include a modulation and coding scheme (MCS) field (not shown) indicating a MCS which is applied to a MSDU430, when the MSDU430is not coded in an UEP mode.

The MAC sub-header420can include an UEP field422, a block ACK field424, and a header check sequence (HCS) field426.

The UEP field422may include information relating to the UEP mode applied to the MSDU430and include an UEP enable field422aand an UEP MCS field422b, where the UEP enable field422aindicates whether the MSDU430is coded in the UEP mode. In accordance with an exemplary embodiment of the present invention as depicted inFIG. 4, the UEP enable field422acan be represented as 0 to indicate that the MSDU430is not coded in the UEP mode.

The UEP MCS field422bcan indicate the MCS applied to the MSDU430which is coded in the UEP mode. However, in accordance with the exemplary embodiment, the MSDU430is not coded in the UEP mode and thus the UEP MCS field422bmay not be used.

The block ACK field424may indicate reception of each of the sub-frames of the received data frame and not be related to the MSDU430included in the ACK frame.

The block ACK field424can comprise first ACK fields424a,424b, and424cwhich indicate reception of each of the sub-frames. When the sub-frames of the received data frame are coded in the EEP mode, the block ACK field424can include the first ACK fields424a,424b, and424c. In addition, the block ACK field424can be formed of 32 bytes and thus can have 256 bits so that the block ACK field424may indicate reception of 256 sub-frames. However, a capacity of the block ACK field424may not be limited to 32 bytes.

The HCS field426is a field to which a HCS, a CRC code for detecting an error in the UEP field422and the block ACK field424, is recorded.

The MSDU430may include arbitrary data. However, data corresponding to the sub-frames included in the received data frame may be included in the MSDU430. For example, when the received data frame is data related to a video conference, the MSDU430may include data related to the video conference. In addition, when the received data frame is related to a moving image, the MSDU430may include a control signal for turning on a power of a device that transmits the moving image or for controlling the volume of the device. Configuration and application of data frame according to an exemplary embodiment of the present invention can be implemented in a variety of manners, including other types of audio/video device, without departing from the scope of the present invention.

As such, when the ACK frame, according to the exemplary embodiment of the present invention, is used, the device that receives the data frame may simultaneously transmit predetermined data and the block ACK using one ACK frame instead of separately transmitting the predetermined data and the ACK frame.

The other fields in the ACK frame illustrated inFIG. 4are described in the IEEE 802.15.3C standard document and thus a detailed description thereof is omitted.

FIG. 5is a diagram illustrating a configuration of an ACK frame according to another embodiment of the present invention.

Referring toFIG. 5, an UEP enable field522acan be represented as 1 to indicate that MSDUs530are coded in the UEP mode.

As illustrated inFIG. 4, an MCS applied to the MSDU530, which is coded in the UEP mode, is recorded to an UEP MCS field522b.

A block ACK field524inFIG. 5may include second ACK fields524a,524b, and524cfor the MSB and second ACK fields524d,524e, and524ffor the LSB. When the sub-frames of the received data frame are coded in the UEP mode, the block ACK field524can comprise the second ACK fields524a,524b,524c,524d,524e, and524f.

In addition, the block ACK field524can be formed of 64 bytes. Also, the second ACK fields524a,524b, and524cfor the MSB have a capacity of 32 bytes and the second ACK fields524d,524e, and524ffor the LSB have a capacity of 32 bytes. However, a capacity of the block ACK field524is not limited to 64 bytes.

Except for such differences, the description of the remaining fields illustrated inFIG. 5is the same with those ofFIG. 4and thus a description of the remaining fields is omitted.

FIG. 6is a block diagram of an apparatus for generating an ACK frame, according to an embodiment of the present invention.

Referring toFIG. 6, the apparatus for generating an ACK frame, according to an exemplary embodiment, may comprise a receiver610, a determination unit620, and a frame generator630.

The receiver610may receive a data frame. The determination unit620can include a first determination unit622and a second determination unit624.

The first determination unit622can determine whether the sub-frames included in the received data frame are coded in the UEP mode.

The second determination unit624can determine whether the data insertion ACK request field requesting the ACK frame including sub-frames or at least one MSDU is included in the received data frame.

According to another embodiment, the determination unit620may be formed of the first determination unit622only.

The frame generator630may generate the ACK frame including the first ACK field or the second ACK field based on the determination of the determination unit620. The first ACK field may indicate the reception of each of the sub-frames, and the second ACK field can show the reception of each first type bit and second type bit in the sub-frames.

Meanwhile, the apparatus for generating the ACK frame may inform the kinds of ACK frames that the apparatus can generate to another apparatus. Here, a capability information frame including information about a capability for generating the ACK frame supported by the apparatus for generating the ACK frame may be used.

Configuration of the apparatus for generating the ACK frame according to an exemplary embodiment of the present invention can be implemented in a variety of manners and comprise other units without departing from the scope of the present invention. For example, the apparatus for generating the ACK frame according to an exemplary embodiment of the present invention can comprise a bus coupling each unit of the apparatus, at least one processor couple to the bus, a memory coupled to the bus to store instructions and to the at least one processor to execute instructions of generating the ACK frame as described earlier.

FIG. 7is a diagram that illustrates the capability information frame according to an embodiment of the present invention.

Referring toFIG. 7, the capability information frame according to the current embodiment may comprise an overall capability field710, a length field720, and a capability information ID730.

The overall capability field710can comprise a device capability field712and a Piconet Coordinator (PNC) capability field714.

The device (DEV) capability field712may show a capability supported by the apparatus for generating the ACK frame and further include information about whether the ACK frame in which data is inserted can be generated, whether the block ACK is generated, whether aggregation can be performed, and whether a two-way communication is supported.

Here, information about aggregation may include information about which aggregation from among MSDU aggregation, MAC Protocol Data Unit MPDU aggregation, and PHY Protocol Data unit PPDU aggregation can be performed.

The PNC capability field714can indicate whether to support capability as a piconet coordinator.

The length field720may indicate a length of the capability information frame.

The capability information ID or Element ID field730can indicate an ID for identifying the capability information frame.

As such, the apparatus for generating the ACK frame can transmit the capability information frame to another apparatus so that a capability information, which can be supported by the apparatus for generating the ACK frame, may be transmitted to the other apparatus.

The embodiments of the present invention can be written as computer programs and can be implemented in general-use digital computers that execute the programs using a computer readable recording medium. Examples of the computer readable recording medium may include magnetic storage media (e.g., ROM, floppy disks, hard disks, etc.), optical recording media (e.g., CD-ROMs, or DVDs), and storage media. Carrier waves (e.g., transmission through the Internet) containing at least one of the embodiments of the present invention may be temporarily or permanently stored in the computer readable recording medium. Configuration or implementation of computer based instructions according to an embodiment of the present invention can be implemented in a variety of manners without departing from the scope of the present invention.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof using specific terms, the embodiments and terms have been used to explain the present invention and should not be construed as limiting the scope of the present invention defined by the claims. The preferred embodiments should be considered in a descriptive sense only and not for purposes of limitation. WPAN in accordance with an exemplary aspect of the present invention may be applicable to various applications as a wire or cable replacement technology for home entertainment systems capable of transmitting and receiving high definition video and audio files. It will be understood by one of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.