KR100778346B1 - Apparatus and method for media access control based cross layer optimization - Google Patents

Abstract

A CLO(Cross Layer Optimization)-based MAC(Medium Access Control) system and a method thereof are provided to efficiently implement QoS(Quality of Service)-guaranteed transmission by horizontally arranging 7 layers of each OSI(Open System Interconnection) model and making CLO information for each layer shared through API(Application Programming Interface) pipelines so that every layer can share various information for many dynamic changes in a wireless environment. A CLO-based MAC system(403) comprises an application API pipeline(401), a MAC API pipeline(402), a Tx packet processing unit, an Rx packet processing unit and a shared pool memory(410). The application API pipeline(401) is provided to make a connection with an upper interface. The MAC API pipeline(402) is provided to make a connection with a lower interface. The Tx packet processing unit receives a CLO application policy descriptor and a CLO MAC policy descriptor from the application API pipeline(401) and the MAC API pipeline(402) and transmits Tx packets to a physical layer. The Rx packet processing unit forwards CLO information for Rx packets, received from the physical layer, to the API pipelines(401,402). The shared pool memory(410) stores Tx packets and Rx packets.

Description

Apparatus and Method for Media Access Control based Cross Layer Optimization}

1 is a diagram illustrating an embodiment of an open system connection (OSI) in a conventional wireless local area network;

2 is a diagram illustrating an exemplary embodiment of a conventional WLAN system structure;

3 is a diagram illustrating an embodiment of a media access control apparatus according to the present invention;

4 is a diagram illustrating an embodiment of a cross layer optimization (CLO) based media access control apparatus according to the present invention.

* Explanation of symbols for the main parts of the drawings

401: Cross-Layer Optimization Based Application API Pipeline

402: Cross-Layer Optimization Based Media Access Control API Pipeline

404: Cross layer optimization based outgoing packet descriptor

405: Receive packet descriptor based on cross layer optimization

406: Send Cross Layer Optimization Packet Descriptor Queue Register File

407: Transmission packet 409: Scheduling / channel access control

410: shared pool memory 411: split / encrypt

412: Transmission packet egress 413: Packet transmission

414: Packet Receive 415: Receive Packet Ingress

416: received packet 417: CRC checker

418: Address matcher 419: Duplicate detector

420: Receive cross layer optimization packet descriptor queue register file

In the present invention, a cross-layer optimization for providing differentiated Quality of Service (QoS) through optimization of a communication layer (cross-layer optimization) in a wireless local area network (hereinafter, referred to as a "wireless LAN"). (CLO: Cross Layer Optimization) based media access control device and method thereof.

In the following embodiment, a cross layer optimization (CLO) based media access control apparatus and method for providing quality of service (QoS) in a wireless LAN will be described, but the present invention is not limited thereto. Reveal in advance.

In general, as the digital era is full-fledged, home appliances are changing to high-speed digital home appliances that transmit high speed and large capacity, and efforts are being made to form them into a network. Above all, consumers' desire for the development of clean and mobile wireless network technology is increasing without the need for laying new lines. This increase in demand is driven by the demand for multimedia streaming services in the WLAN.

The feature of multimedia streaming, which requires a relatively large amount of transmission, is a real-time service, so a function for supporting it at the application layer and the network layer is required, and such a requirement is a requirement for supporting quality of service (QoS). In addition, there is a need for a method for supporting Quality of Service (QoS) over all layers to enable transmission while overcoming a relatively low bandwidth and unstable channel state of a wireless network.

In an effort to support quality of service (QoS) of the application layer and the network layer, a number of transmission techniques have been proposed in the prior art to emphasize error-resilient. Typical techniques related to this are wireless multimedia transmission schemes through proper mixing of basic transmission error control modules such as Forward Error Correction (FEC), Automatic Repeat Request (ARQ), and Interleaving.

The Internet, which is designed in a layered structure, has a great influence on the structure of the wireless network. However, a tightly layered architecture is not efficient enough to handle many dynamic changes in the wireless environment, nor is it effective in optimizing the performance of the wireless network. As a result, much research has been conducted to solve the problems of the wireless network design structure, which has been developed into a technique called cross-layer optimization (CLO). In particular, by introducing such a concept in the multimedia streaming, the prior art has been researched to adaptively share and transmit information between layers in a layered structure.

A description of a conventional technique based on a cross layer optimization (CLO) technique is described with reference to FIG. 1.

1 is a diagram illustrating an embodiment of an open system connection (OSI) in a conventional wireless local area network, and illustrates a cross layer structure.

As shown in FIG. 1, a cross layer structure based on a conventional open system connection (OSI) is configured to share information organically between layers in an existing vertical layer.

Information sharing between the physical layer 101, 102, data link 103 layer, network layer 107, middleware layer 108, and application layer 109 is shared between each layer or through interaction 110. This information is managed through the network management layer 111.

The wireless access function 101 having multiple input multiple outputs (MIMO) is matched with the physical layer 102 to form a physical layer.

When the transmission of data is determined at the application layer 109, the data is transmitted through the middleware layer 108 according to the network protocol function of the network layer 107. At this time, the operation of the network layer 107, the middleware layer 108, and the application layer 109, which are upper layers, is performed with the help of the operating system 106.

The data to be transmitted is delivered to the MAC device, which is the data link layer 103, through the host interface 104 under the control of the device driver 105.

Data is transferred to the memory element 113 with the input / output of the bus and with the help of a Direct Memory Access (DMA) device 112, and under the control of the MAC protocol processor 115. Data in element 113 is moved to transmit FIFO 116.

Data in the transmit packet (FIFO) 116 is transferred to the physical layer 102 under the control of the medium access control (MAC) protocol processor 115.

Since the reception process that can be described in the opposite direction of the data flow in the above-described transmission process is an embodiment of the conventional technology, description thereof will be omitted.

In the prior art embodiment of FIG. 1, when applied to a multimedia streaming system, the media server at the application layer 109 may track packet loss and coordinate the transmission of media corresponding thereto.

To reduce information loss, the media server uses packet forward error correct (FEC) coding and unequal error protection (UEP).

In the network layer 107 including the transport layer, various cross layer approaches have been proposed and studied as an alternative to the existing transmission control protocol (TCP). It can be distinguished from loss for other reasons, providing the ability to invoke other flow control mechanisms.

The data link layer 103 allows the persistence level of the Automatic Repeat Request (ARQ) mechanism to operate according to the delay and reliability requirements of each application. As a result, the embodiment of FIG. 1, which is a conventional technology, refers to a technique for enabling service in an optimal environment by sharing and using various information between layers in an OSI-based layer. This technique is called cross-layer optimization (CLO) technique.

In the prior art based on the cross-layer optimization (CLO) technique as described above, it is essential to guarantee the quality of service (QoS). In addition, with the rapid growth of the Internet, coupled with the rapid adoption of wireless technology, there is no doubt that the demand for wireless data services is increasing. In the future, traffic in the wireless network is expected to have a mixed form of real-time traffic such as voice, multimedia teleconferencing, games, data traffic (eg, messenger, file transfer, etc.). These applications require different quality of service (QoS) guarantees depending on the type of traffic provided.

Various mechanisms have been devised to meet the demand for quality of service (QoS) guarantees in wireless data services. Most technologies are based on the wireless data transmission technology of the wireless broadband network supporting data services in the 2.5G and 3G cellular systems based on the wireless local area network based on the IEEE 802.11 or HyperLAN standard.

The development of the conventional technologies and techniques described above is based on the existing Open System Connectivity (OSI) seven layers, using conventional wireless transmission techniques such as WLAN (WLAN) technology, information sharing between each layer or cross-layer optimization (CLO). The conventional technique is to guarantee the quality of service (QoS) by sharing information of the method.

However, the conventional technology has a high layer in which the overall system performance is drastically reduced due to lack of transmission capacity, multi-path fading, Doppler effect, and time and frequency dispersion fading effect which are fundamental problems in the wireless environment. It is a method of operation to guarantee the quality of service (QoS) by simply notifying to the information sharing based on cross-layer optimization (CLO) based on this information, and has many problems.

In WLAN, as a fundamental endeavor to guarantee quality of service, quality of service (QoS) has been reinforced at the MAC layer.

The medium access control (MAC) protocol used in the conventional wireless LAN (WLAN) is a distributed coordination function (DCF) method for providing best effort service and a point coordination function (PCF) method for providing real time service. Among them, only DCF (Distributed Coordination Function) method is actually used in most commercial WLAN system, and PCF (Point Coordination Function) method is rarely used due to the fundamental limitation of this method. It is true.

As a result, a task group e (TGe: Task Group e) within the IEEE 802.11 Working Group (TG) was formed to standardize the new media access control (MAC) protocol to provide real-time multimedia services. Standardization has been made for a new medium access control (MAC) protocol to provide quality of service (QoS).

IEEE802.11e is based on a new medium access control (MAC) protocol for enhanced quality of service (QoS), an enhanced distributed channel access (EDCA) scheme and a new medium access control (MAC) transmission scheme called HCF controlled channel access (HCCA). This is a new medium access control (MAC) transmission method that improves existing distributed coordination function (DCF) and point coordination function (PCF) in terms of quality of service (QoS) and its transmission efficiency.

EDCA (Enhanced Distributed Channel Access) is to discriminate relative quality of service (QoS) for traffic of each access category (AC), and it is a method that cannot satisfy accurate service requirements for each access category (AC). . This is a method that can be compared with DiffServ (Differentiated Service), which is a method of providing relative quality of service (QoS) in IP networks. In contrast, HCCA (HCF Controlled Channel Access) method is a method of providing absolute quality of service (QoS) in units of a medium access control (MAC) link. This is a method corresponding to IntServ (Integrated Service), which is a method of providing absolute quality of service (QoS) in the IP network, and is a method of providing absolute quality of service (MAQ) in units of MAC.

2 is a diagram illustrating an exemplary embodiment of a conventional WLAN system structure.

As shown in FIG. 2, the structure of a conventional WLAN system is largely a radio frequency / analog subsystem (RF) for connecting a wireless channel 201 through a multiple input multiple output (MIMO) wireless connection. A Radio Frequency / Analog Subsystem (202), a Media Access Control Subsystem (207) that modulates / demodulates a signal received wirelessly or a signal to be transmitted wirelessly, and a higher layer. A host subsystem 209 that performs functions.

The media access control subsystem 207 includes a physical layer interface 217, a media access control controller 210, a shared memory 216 for storing packets, and a host bus interface 211 that interfaces with a host subsystem. Equipped.

The host subsystem 209 is organically coupled with the processing unit 214 and the processing unit 214 for controlling the operation of the host interface 212 and the host subsystem 209, which are interfaced with the media access control subsystem 207. The memory unit 215 operates, and an input / output interface 213 interfaces with an external environment.

The media access control subsystem 207 provides a media access control function defined by IEEE 802.11e to support a quality of service (QoS) function.

In the media access control subsystem 207, quality of service (QoS) is realized through an additional coordination function called HCF. This function is operated in the medium access control controller 210.

HCF exists only in a Quality of Service (QoS) network (QBSA) configuration and runs on all QSTAs. HCF uses a collision-based channel approach called Enhanced Distributed Channel Access (EDCA) and a control channel approach called HCF Controlled Channel Access (HCCA).

QSTA can obtain TXOP (Transmission Opportunity) using the above two channel approaches.

The TXOP (Transmission Opportunity) obtained by the collision-based channel approach is called EDCA TXOP, and the TXOP (Transmission Opportunity) obtained by the control channel approach is called HCCA TXOP.

EDCA provides a distributed channel approach to eight user priorities (UPs) in QSTA. EDCA defines four access categories (ACs), which provide traffic transfer of different user priorities (UPs).

Each Access Category (AC) competes with TXOP as an Enhanced Distributed Channel Access Function (EDCAF), an enhanced version of DCF. This EDCAF basically defines parameter values in an EDCA Parameter Set or is defined by parameters received in QAP.

EDCAF parameters for control are defined in "dot11QAPEDCA -Table" in QAP or "dot11EDCATable" in non-AP QSTA. The smallest idle time interval is not a fixed value (DIFS) as in DCF, but a Management Entity or a variable defined by QAP.

The contention window limit "CWmin" or "CWmax" is not a fixed value but a variable. When a collision occurs between different EDCAFs in a QSTA, an Access Category (AC) with a high priority gets a TXOP and thus transmits data frames. However, the AC (Access Category) with low priority will behave as if an external conflict has occurred.

The QSTA may transmit several frames in the same access category (AC) during the EDCA TXOP time obtained by the EDCAF.

The time interval of EDCA TXOP is limited. When the value is "0", it means that one frame is completely transmitted instead of the time interval of EDCA TXOP.

The QAP transmits the EDCA parameters by the selected beacon, probe response and association response frames.

QSTA uses the default parameter value if none of the above elements are received.

The HCF controlled channel access (HCCA) uses a hybrid coordinator (HC) with a central control function that enables quality of service (QoS), but operates differently from the PCF's PC.

The HC is in a QAP (QoS Access Point), and starts frame transmission using high priority (Priority) to access the channel of the HC, and also distributes TXOP to itself and other QSTAs.

The traffic transmission of HC and the distribution of TXOP are scheduled in Contention Period (CP) and Contention Free Period (CFP) periods to satisfy the requirements of specific traffic category (TC) and quality of service (QoS) of TS (Traffic Service). To make it work.

The above described media access control methods EDCA and HCCA only support quality of service (QoS) guarantees in the media access control method. The information and association of the upper layer process operating in the host subsystem 209 is only limited to sharing information between layers in the hierarchical and vertical structure as shown in FIG. 1, so that the media access control function cannot use the information of all layers. There was this.

On the other hand, as an example using the conventional technology, the operating parameter adjustment method of the wireless LAN system disclosed in the Republic of Korea Patent Application No. "10-2003-0093279" relates to the operating parameter adjustment method of the wireless LAN system. In a WLAN system to which IEEE802.11e is applied, priority discrimination degree is calculated for each traffic type, and an initial operation parameter value for each traffic type is set to a value satisfying the priority difference degree. The amount of traffic for each type of traffic generated within a specific section having a certain length is calculated for each operation period of the operating parameter value adjusting algorithm, and the base information for adjusting the operating parameter value is calculated based on the obtained traffic amount. Subsequently, after determining whether to adjust the operation parameter value based on the calculated base information, if it is necessary to adjust the operation parameter value, a method of adjusting the operation parameter value.

As another example using the conventional technology, the wireless LAN system of the HCCA operation method disclosed in the Republic of Korea Patent Application No. "10-2004-0109017" and the traffic service method in the system is based on the HCCA operation method After performing the HC function, the mobile terminal is wirelessly connected to the base station, and classifies traffic of the service target according to the generation pattern to define the TSPEC according to the quality of service (QoS) characteristics to receive the WLAN traffic service. At this time, the base station and the wireless terminal is characterized in that the service policy by determining the operation policy in the medium access control (MAC) layer based on the TSPEC defined according to the traffic generation pattern.

As another example using the related art, the present invention relates to a method and a wireless device for differentiating quality of service in a wireless network disclosed in Korean Patent Application No. "10-2005-7016011", and in a distributed manner, a medium access control (MAC) layer parameter. Provide differentiated quality of service (QoS) by providing adaptive updates to. The proposed method includes calculating a probability of failure for transmission over a network, determining a target value for determining a contention window according to a mapped function of the probability of failure, and changing the contention window according to a scaling function of the target value. Steps. Mapped functions and scaling can provide quality of service (QoS) differentiation. The wireless device can match the contention window according to a mapped function of one or more probabilities to ensure fairness in the wireless time slotted network, to enable changes in the contention window, and to provide new parameters for the media access control (MAC) layer. Network interface card (NIC), network driver interface, network monitor, statistics engine and adaptive parameter engine for determining a target value for determining a target value.

As another example using a conventional technology, the present invention relates to a WLAN medium access control frame transmission apparatus and method for EDCA support disclosed in Korean Patent Application No. "10-2003-0095002". The WLAN media access control frame transmission apparatus according to the present invention generates a media access control frame, and classifies and stores the media access control frame according to user priority information transmitted from an upper logical link control layer unit in a WLAN. A network card controller; And a WLAN network card for transmitting the media access control frame stored in the buffer, the buffer including a first buffer area for storing the frame being transmitted and a second buffer area for storing the next frame to be transmitted.

As another example using a conventional technology, the present invention relates to a power efficient transmission method, system, and program product of scalable video over a wireless network disclosed in Korean Patent Application No. "10-2005-7015348". A method and system for reducing power consumption in a wireless network is disclosed by adjusting the transmit energy for each bit in the physical layer and the retry limit in the MAC. The method generates a lookup table that includes an optimal pair (Nlim, Et) for a plurality of different transmission characteristic sets, where "Nlim" is the retry limit and "Et" is the transmit energy per bit, and the wireless network Determining a set of transmission characteristics for the scalable video sequence to be transmitted via the method; accessing a lookup table to obtain an optimal pair (Nlim, Et) corresponding to the determined set of transmission characteristics; Transmitting a sequence of scalable video over the wireless network using (Nlim, Et). The present invention takes into account the situation in which scalable video data is transmitted over a WLAN and retransmission is employed as an error control technique. One purpose of this method is to maintain a constant video quality at the receiver side while minimizing the overall transmit power, or to optimize the video quality given a fixed upside down transmit power resource.

As another example using conventional techniques, the present invention relates to a method, apparatus, and system for media access control disclosed in Korean Patent Application No. "10-2006-7009449". Embodiments are disclosed that address media access control (MAC) processing for efficient use of high throughput systems. In one aspect, an apparatus includes a first layer that receives one or more packets from one or more flows and generates one or more first layer protocol data units (PDUs) from the one or more packets. In another aspect, the second layer is applied to generate one or more medium access control (MAC) frames based on one or more medium access control (MAC) layer protocol data units (PDUs). In another aspect, a medium access control (MAC) frame is applied to transmit one or more medium access control (MAC) layer protocol data units (PDUs). A medium access control (MAC) frame may include a control channel for transmitting one or more assignments. A medium access control (MAC) frame may include one or more traffic segments depending on the allocation.

The conventional technique is a technique of defining a traffic type and prioritizing according to the definition to determine operating parameters and then attempting to guarantee a quality of service (QoS) based on this information in a medium access control (MAC), or a medium access control. An embodiment of providing a method and an apparatus for providing a quality of service (QoS) differentiation by varying an operation policy at a (MAC) level is illustrated.

As described above, the conventional techniques mainly use only the first to second layers among the seven layers of the open system connection (OSI) model, or perform the results in the application layer that is the highest layer based on the state information of the first layer. It provides a method and apparatus for reflecting the second layer. These methods, based on vertical or strictly hierarchical structures, are inefficient to cope with many dynamic changes in the wireless environment, and are also an obstacle to optimizing the performance of the wireless network.

In addition, the media access controller and the method of the present invention already operate in accordance with the result of determining the quality of service (QoS) policy in the upper layer, and media access using information sharing between each layer based on cross layer optimization (CLO). There is a limit because it is not a control method. Using existing media access controllers and methods as they are, cross-layer optimization (CLO) -based inter-layer design can be achieved in a tangled design without a formal framework, where modification of one functional module can span all protocols. This affects the efficient function module management. In addition, cross-layer optimization (CLO) based designs also have the potential to cause unintended behavior between protocols, such as when infinite loops occur during adaptation due to performance degradation.

The present invention has been proposed to solve the above problems, and by arranging seven layers of each open system connection (OSI) model horizontally, cross-layer optimization (CLO) information for each layer is applied to an application programming interface. Cross-layer optimization (CLO) based media access control device to be shared through the pipeline, and the upper application layer supports cross-layer optimization (CLO) information to the media access controller through the API pipeline. And a method thereof.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

An apparatus of the present invention for achieving the above object is a cross-layer optimization (CLO) based media access control device, the application API pipeline for connecting the upper interface: media access control API pipeline for connecting the lower interface ; When the packet is transmitted, a cross layer optimization (CLO) application policy descriptor and a cross layer optimization (CLO) media access control policy descriptor are received from the application API pipeline and the media access control API pipeline to transmit the transmission packet to the physical layer. Transmission packet processing means; Receiving packet processing means for delivering cross-layer optimization (CLO) information on received packets received from the physical layer to the application API pipeline and the media access control API pipeline; And shared storage means for storing the transmission packet and the reception packet.

Meanwhile, the method of the present invention for achieving the above object, in the cross-layer optimization (CLO) based media access control method, cross-layer optimization (CLO) based application API pipeline and cross-layer optimization (CLO) based media access A control information input / output step for receiving input / output of control information from a control API pipeline; And cross-layer optimization (CLO) application policy descriptor and cross-layer optimization from the cross-layer optimization (CLO) based application API pipeline and the cross-layer optimization (CLO) based media access control API pipeline when transmitting and receiving control information. Receiving a CLO) media access control policy descriptor to construct a cross-layer optimization (CLO) based send / receive packet descriptor.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, whereby those skilled in the art may easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a diagram illustrating an embodiment of a media access control apparatus according to the present invention, and illustrates a horizontal hierarchical structure of an open system connection (OSI) model using two cross-layer optimization (CLO) based API pipelines.

As shown in FIG. 3, when looking at the horizontal hierarchical structure of the open system connection (OSI) model according to the present invention, an interface between each layer is an upper interface 311 and a lower interface 312. Divided into

The upper interface 311 is connected by a cross layer optimization (CLO) based application API pipeline 302, and the lower interface 312 is connected by a cross layer optimization (CLO) based media access control API pipeline 310. Connected.

The application layer 301 is connected to each layer 303, 304, 305, 306, 307, 308 through two pipelines.

The application layer 301 may receive information of each layer or transmit an operation command through the cross layer optimization (CLO) based application API pipeline 302.

Since the data is transmitted through a medium access control (MAC) layer 309, each layer is connected to a medium access control (MAC) layer 309 via a cross layer optimization (CLO) based medium access control API pipeline 310. You can provide or receive the information necessary for data transmission.

Examples of information that can be shared by each layer are as follows.

The function of the Physical Layer 308 is to transmit data using a suitable power over a certain distance with a minimum bit error rate. The physical layer 308 may use information about transmission power, bit error rate, encoding and modulation in use. However, for the explicit measurement of the bit error rate, the receiver must provide feedback to the transmitter. This feedback information is delivered to the required layer through the cross layer optimization (CLO) based media access control API pipeline 310 and the cross layer optimization (CLO) based application API pipeline 302.

The functions of the media access control (MAC) layer 309 improve the reliability of the link through forward error correction (FEC) and automatic repeat request (ARQ). In addition, a method of avoiding or reducing collisions and a method of dividing data into frames in order to guarantee transmission reliability with minimum overhead may be used.

The media access control (MAC) layer 309 can use information such as the Forward Error Correction (FEC) method, the number of retransmitted frames, the length of the frames, when the wireless media can be transmitted, and the associated events sent and received. This information may be conveyed to the required layer through the cross layer optimization (CLO) based media access control API pipeline 310 and the cross layer optimization (CLO) based application API pipeline 302. If the channel conditions are not good, retransmission at the MAC layer 309 introduces a delay, which in turn causes retransmission of the transport layer 306, resulting in reduced throughput. . To avoid this operation, the transport layer 306 and the medium access control (MAC) layer 309 need to exchange retransmission information. This exchange of information is also possible in the cross layer optimization (CLO) based media access control API pipeline 310 and the cross layer optimization (CLO) based application API pipeline 302.

The network layer 307 has routing, address assignment, network interface selection, and IP hand-off capabilities to maintain IP connectivity in an external network. Information available at the network layer 307 includes mobile-IP (IP) handoff initialization / completion events and the network interface currently in use. This exchange of information is also done in the cross layer optimization (CLO) based media access control API pipeline 310 and the cross layer optimization (CLO) based application API pipeline 302.

In the above-described example, the application layer 301 has described an example in which the application layer 301 may receive information of the layer or transmit an operation command through two API pipelines 302 and 310. When the application layer 301 wants to transmit data by using information sharing between the layers, the media access control (MAC) layer 309 is a cross-layer optimization (CLO) based media access control API pipe from the application layer 301. Data is transmitted using the information received through the line 310.

FIG. 4 is a diagram illustrating an embodiment of a cross layer optimization (CLO) based media access control apparatus according to the present invention, and illustrates an example of implementing the media access control (MAC) layer 309 of FIG.

As shown in FIG. 4, the structure of the cross-layer optimization (CLO) based media access control device 403 of the present invention is a cross-layer optimization (CLO) based application API pipeline 401 and cross-layer optimization (CLO). The control information is input / output from the two API pipelines 401 and 402 of the media access control API pipeline 402.

At the time of transmission, the cross-layer optimization (CLO) application policy descriptor and the cross-layer optimization (CLO) media access control policy descriptor are received from two API pipelines (401, 402) to construct a cross-layer optimization (CLO) based outgoing packet descriptor 404. do. This is stored in the transmit cross layer optimization (CLO) packet descriptor queue register file 406. The transmit cross layer optimization (CLO) packet descriptor queue register file 406 has a transmit cross layer optimization (CLO) packet pointer that points to the actual packet to transmit in shared pool memory 410.

The scheduling and channel access control 409 is performed according to the information stored in the transmission cross layer optimization (CLO) packet descriptor queue register file 406. In addition, fragmentation and encryption 411 are also performed in accordance with the information stored in the transmit cross layer optimization (CLO) packet descriptor queue register file 406.

This control is made to transmit 413 to the physical layer via the transmit packet egress block 412.

Upon receipt of data from the physical layer 414, the received packet enters the receive packet ingress block 415, which receives the address through the CRC checker 417 and the address matcher 418. It is determined whether the packet is ingress together with the match or duplicate detector 419 of the same packet.

When a packet is ingressed, it is stored in the shared pool memory 410, and each received packet stores information of the received packet in the received cross-layer optimization (CLO) packet descriptor queue register file 420. This information is again stored in the cross-layer optimization (CLO) based receive packet descriptor 405, through which cross-layer optimization (CLO) information is sent to the two API pipelines (401, 402).

Information on the transmission data that can be recorded through the cross-layer optimization (CLO) -based transmission packet descriptor 404 at the time of transmission includes ACK policy, transmission speed, frame length, encryption type, encryption key type, queue number, and the like. And cross-layer optimization (CLO) information received from all layers for transmitting the TX packet 407 stored in the shared pool memory 410.

Information about received data that can be recorded through the cross-layer optimization (CLO) based receive packet descriptor 405 at the time of reception includes receiving rate, frame length, received signal strength indication (RSSI), signal to noise ratio (SNR), It includes all cross-layer optimization (CLO) information available to all other layers for received packets stored in shared pool memory 410, such as pointers to received (RX) packets 416.

As described above, the present invention arranges the seven layers of the Open System Connectivity (OSI) model in a horizontal structure, allows information sharing between each layer to be interfaced through two API pipelines, and the top application layer is divided into two. The API pipeline allows you to collect cross-layer optimization (CLO) information for each layer or to pass commands. Cross layer optimization (CLO) information received or delivered through two API pipelines is transmitted / received using a transmit / receive packet descriptor containing cross layer optimization (CLO) information in a MAC controller according to the present invention. Receive. As a result, the media access controller of the present invention controls the data transmission using all the information of each layer to efficiently handle many dynamic changes in the wireless environment, thereby providing quality of service (QoS).

As described above, the method of the present invention may be implemented as a program and stored in a recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.) in a computer-readable form. Since this process can be easily implemented by those skilled in the art will not be described in more detail.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

As described above, according to the present invention, since the MAC controller based on the 7th layer of the conventional open system connection (OSI) model is not effective to handle many dynamic changes in a wireless environment, each open system connection ( Device and method for arranging OSI) Model 7 horizontally so that Cross-Layer Optimization (CLO) information for each layer is shared through API pipeline and supporting Media Access Control By providing a system, all layers share various information on a large number of dynamic changes in a wireless environment, and by controlling this, it is possible to more efficiently guarantee transmission of quality of service (QoS).

Claims (10)

In the cross-layer optimization (CLO) -based media access control device, Application API pipeline for connecting the parent interface: A media access control API pipeline for connecting sub-interfaces; When the packet is transmitted, a cross layer optimization (CLO) application policy descriptor and a cross layer optimization (CLO) media access control policy descriptor are received from the application API pipeline and the media access control API pipeline to transmit the transmission packet to the physical layer. Transmission packet processing means; Receiving packet processing means for delivering cross-layer optimization (CLO) information on received packets received from the physical layer to the application API pipeline and the media access control API pipeline; And Shared storage means for storing transmitted and received packets Cross layer optimization (CLO) based media access control device comprising a. The method of claim 1, The transmission packet processing means, Cross-Layer Optimization (CLO) for receiving and processing a Cross-Layer Optimization (CLO) Application Policy Descriptor and a Cross-Layer Optimization (CLO) Media Access Control Policy Descriptor from the Application API pipeline and the Media Access Control API pipeline upon packet transmission. Based transmission packet descriptors; A transmit cross layer optimization (CLO) packet descriptor queue register for storing the cross layer optimization (CLO) based transmit packet descriptor; Scheduling / channel access control means for performing scheduling and channel access control according to the information stored in the transmission cross layer optimization (CLO) packet descriptor queue register; Partitioning / encryption means for performing fragmentation and encryption in accordance with information stored in the transmission cross layer optimization (CLO) packet descriptor queue register; And Transmission packet egressing means for controlling said scheduling / channel access control means and said partitioning / encryption means and transmitting a packet to said physical layer Cross layer optimization (CLO) based media access control device comprising a. The method of claim 2, The cross layer optimization (CLO) based transmission packet descriptor, Information on transmission data that can be recorded includes ACK policy, transmission speed, frame length, encryption type, encryption key type, queue number and received from all layers for transmitting transmission packets stored in the shared storage means. Cross layer optimization (CLO) based media access control device comprising a cross layer optimization (CLO) information. The method of claim 3, wherein The transmit cross layer optimization (CLO) packet descriptor queue register is Cross layer optimization (CLO) based media access control device having a transmission cross layer optimization (CLO) packet pointer to indicate the packet to be transmitted in the shared storage means. The method of claim 2, The received packet processing means, Packet incrementing means for receiving a packet from the physical layer and determining whether to ingress; A receive cross layer optimization (CLO) packet descriptor queue register for storing each received packet received through said packet engraving means; And Cross layer optimization (CLO) based to store information from the receive cross layer optimization (CLO) packet descriptor queue register to convey cross layer optimization (CLO) information to the application API pipeline and the media access control API pipeline. Receive Packet Descriptor Cross layer optimization (CLO) based media access control device comprising a. The method of claim 5, The cross layer optimization (CLO) based received packet descriptor, Information about received data that can be recorded includes reception speed, frame length, RSSI (Received Signal Strength Indication), Signal to Noise Ratio (SNR), pointer of received packet, and the received packet stored in the shared storage means. Cross layer optimization (CLO) based media access control device, characterized in that all other layers include all available cross-layer optimization (CLO) information. The method according to any one of claims 1 to 6, The application API pipeline connects an upper interface among interfaces between layers of an open system connection (OSI) model, The media access control API pipeline, the cross-layer optimization (CLO) based media access control device, characterized in that for connecting the lower interface of the interface between the layers of the Open System Connectivity (OSI) model. In a cross layer optimization (CLO) based media access control method, A control information input / output step of receiving input / output of control information from a cross layer optimization (CLO) based application API pipeline and a cross layer optimization (CLO) based media access control API pipeline; And Cross layer optimization (CLO) application policy descriptor and cross layer optimization (CLO) from the cross layer optimization (CLO) based application API pipeline and the cross layer optimization (CLO) based media access control API pipeline when transmitting and receiving control information Packet descriptor configuration step of receiving media access control policy descriptor and constructing cross-layer optimization (CLO) based send / receive packet descriptor Cross layer optimization (CLO) based media access control method comprising a. The method of claim 8, The packet descriptor configuration step, A transmission packet descriptor storing step of storing a transmission packet descriptor in a transmission cross-layer optimization (CLO) packet descriptor queue register file when data is transmitted; And A transmission packet processing step of performing scheduling, channel access control, partitioning, and encryption through a transmission packet egress block according to information stored in the transmission cross layer optimization (CLO) packet descriptor queue register file and transmitting the same to the physical layer. Cross layer optimization (CLO) based media access control method comprising a. The method of claim 9, The packet descriptor configuration step, An ingress determination step of determining whether the packet is ingress through CRC checking, address matching, or overlapping of the same packet through a received packet ingress block when receiving data from the physical layer. ; A reception information storage step of storing the received packet in a shared pool memory when the packet is ingressed in the ingress determination step, and storing information of each received packet in a reception cross-layer optimization (CLO) packet descriptor queue register file; And The information stored in the receiving information storage step is stored in the cross layer optimization (CLO) based receiving packet descriptor again to store the cross layer optimization (CLO) based application API pipeline and the cross layer optimization (CLO) based medium access control API pipeline. To output the cross layer optimization (CLO) information through the cross layer optimization (CLO) information Cross layer optimization (CLO) based media access control method comprising a.

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