JP6128580B2 - COMMUNICATION DEVICE, COMMUNICATION CONTROL METHOD, AND PROGRAM - Google Patents

Description

  The present invention relates to a communication device that controls operations in a plurality of communication layers, a communication control method, and a program that is executed by a computer.

  The communication device performs communication using a protocol suite having a plurality of communication layers arranged in a hierarchy. As one of the protocol suites, an Internet protocol suite is known (see Non-Patent Document 1). The Internet protocol suite is classified into four layers: a link layer, an Internet layer, a transport layer, and an application layer.

  The application layer is the top layer of the Internet protocol suite, providing various services using data communication, mutual conversion between data and user-friendly forms, and management of virtual connections for sending and receiving data And so on.

  The transport layer provides end-to-end communication services for applications. As a protocol classified into the transport layer, for example, there is TCP (Transmission Control Protocol).

  For the Internet layer, Internet Protocol (IP) is used to carry data from the source to the destination host. IP is a connectionless or datagram internetwork service and does not provide end-to-end delivery guarantees. IP performs addressing, service type designation, frame division and assembly.

  For the link layer, in order to communicate on the network to which the communicator is directly connected, the communication protocol used to interface to the network must be implemented. This protocol is called a link layer protocol.

  Each communication layer can communicate only with an adjacent layer. In addition to the Internet protocol suite, an OSI (Open Systems Interconnection) reference model (see Non-Patent Document 2) is also known as the protocol suite, but the protocol suite is substantially the same in that it is divided into layers.

  Such a protocol suite has been considered on the premise of stable wired communication as disclosed in Non-Patent Document 3.

  However, communication environments such as wireless communication, optical communication, and energy-saving communication have been diversified today, and there have been cases where the above-described hierarchical access alone does not work well. For example, Non-Patent Document 4 describes the necessity of cross-layer access in a wireless ad hoc network. Further, as defined in Non-Patent Document 5, when securing mobility in an unstable wireless network, it is necessary to control the TCP parameters according to the parameters of the data link layer. That is, free cross-layer access is required between communication layers. Cross-layer access refers to access from one communication layer to another communication layer across adjacent communication layers.

  A plurality of types are known as methods for freely accessing each communication layer. In Non-Patent Document 6, the method is classified into three types, “new abstraction type”, “common database type”, and “direct communication type”.

  The “new abstraction type” is a communication format in which each communication layer is not hierarchized and operates completely independently. However, there is a problem that compatibility with a communication device using an existing communication layer is lost. Communication systems that use the Internet are designed to use communication layers such as the Internet layer and the transport layer. However, this communication layer structure that is already widely used is ignored, and everything is recreated from scratch and used. It is unrealistic.

  The “common database type” is a method of providing one new hierarchy called “cross layer optimizer” as disclosed in Patent Document 1, for example. This is a method of providing a new layer and controlling all layers of the layered communication system.

  However, since one layer is a method of grasping all information and finally judging it, it works well for one purpose, but in the future, multiple applications such as smartphones will be used for various purposes. When a plurality of operations are performed by switching, it is difficult for a single hierarchy to comprehensively judge and optimize. Further, in order to obtain various information from each communication layer, a necessary number of interfaces for communication must be provided for each communication layer, which may increase the number of interfaces. Therefore, there is a problem that management is complicated and scalability is poor.

  The “direct communication type” is a method for realizing cross-layer access between individual layers of a hierarchical communication system. When a plurality of applications are exchanged in this way, it is considered better that individual applications and communication layers operate independently.

  Non-patent document 7 classifies the “direct communication type” method in more detail. In non-patent document 7, “CLASS” is proposed as an optimal access method.

Special table 2007-515833 gazette

RFC1122, "Requirements for Internet Hosts-Communication Layers" ISO 7498, "Information processing systems-Open Systems Interconnection-Basic Reference Model" "Cross-layer networking technology in wireless communication", IEICE Technical Report, vol. 108, no. 447, AN2008-76, pp. 71-76, March 2009 “Cross-layer signaling-based load control method for wireless ad hoc networks”, IEICE Technical Report, vol. 106, no. 356, CQ2006-76, pp. 95-100, November 2006 RFC 3481, "TCP over 2.5G and 3G Wireless Networks" Srivastava, V .; Motani, M. "Cross-layer design: a survey and the road ahead", IEEE Communications Magazine. Volume 43, Issue 12, Dec. 2005, Page (s): 112- 119 Qi Wang; Abu-Rgheff, M.A. "Cross-layer signaling for next- generation wireless systems", IEEE Wireless Communications and Networking conference, WCNC 2003.Volume 2, 16-20 March 2003, Page (s): 1084- 1089

  However, the technique disclosed in Non-Patent Document 7 merely defines a message between communication layers, and does not specifically show a mechanism for accessing beyond the communication layer. Non-Patent Document 6 proposes to define a message format by a “direct communication type” method, but does not specifically show how to implement the message format.

  The present invention has been made in order to solve the above-described problems of the technology, and a communication apparatus, a communication control method, and a computer that can easily perform cross-layer access to a plurality of communication layers. The purpose is to provide a program.

In order to achieve the above object, a communication device of the present invention provides:
A memory storing a table describing functions included in the protocol for managing protocol processing operations in a plurality of hierarchical communication layers by an event model including elements of event reception, event processing, and event transmission And
When transmitting / receiving data to / from an external communication device via the plurality of hierarchical communication layers, information exchanged between each communication layer is defined as an event, and the protocol processing operation of each communication layer is defined by the event model. And managing the connection information between each communication layer and the mapping of processing operations of each communication layer as a chain by communication unit using the table, and referring to the table when receiving the event, according to the chain This is a configuration having a control unit that determines and executes which function is used among the functions included in the protocol in the layer.

The communication control method of the present invention is a communication control method by a communication device,
A memory storing a table describing functions included in the protocol for managing protocol processing operations in a plurality of hierarchical communication layers by an event model including elements of event reception, event processing, and event transmission A communication control method by a communication device having a unit,
When transmitting / receiving data to / from an external communication device via the hierarchical communication layers, information exchanged between the communication layers is defined as an event.
Manage the processing operation of each communication layer protocol with the event model,
Using the table, the connection information between the communication layers and the mapping of processing operations of the communication layers are managed as a chain in communication units, and when the event is received, the table is referred to according to the chain according to the chain. Of the functions included in the protocol, which function is used is determined and executed.

Furthermore, the program of the present invention is stored in a computer.
A memory storing a table describing functions included in the protocol for managing protocol processing operations in a plurality of hierarchical communication layers by an event model including elements of event reception, event processing, and event transmission A computer having a
A procedure for defining information exchanged between each communication layer as an event when transmitting / receiving data to / from an external communication device via the plurality of hierarchical communication layers;
A procedure for managing the processing operation of each communication layer protocol by the event model,
Using the table, the connection information between the communication layers and the mapping of processing operations of the communication layers are managed as a chain in communication units, and when the event is received, the table is referred to according to the chain according to the chain. The computer is caused to execute a procedure for determining and executing which of the functions included in the protocol is to be used.

  According to the present invention, it is possible to easily execute cross-layer access by performing processing according to an event model defined in advance with respect to operations in a plurality of communication layers.

It is a block diagram which shows the example of 1 structure of the communication apparatus of 1st Embodiment. It is a figure which shows an example of the protocol suite performed by the control part shown in FIG. FIG. 3 is a functional block diagram showing a virtual configuration realized by a CPU executing the protocol shown in FIG. 2. It is a schematic diagram which shows the information processing method in case two communication apparatuses communicate. It is a figure for demonstrating cross layer access. It is a figure which shows an example of the upstream process table for determining the process procedure of the upstream direction of a communication layer in 1st Embodiment. It is a figure which shows an example of the down process table for determining the process procedure of the down direction of a communication layer in 1st Embodiment. In 1st Embodiment, it is a flowchart which shows a procedure for a control part to determine a protocol in each communication layer. It is a figure for demonstrating operation | movement of the communication apparatus of 1st Embodiment. It is a figure for demonstrating the protocol suite in 2nd Embodiment. In 2nd Embodiment, it is a flowchart which shows the procedure of execution of the function in the protocol by a control part. In 2nd Embodiment, it is a figure which shows an example of the uplink process table for determining the process procedure of the uplink direction of a communication layer. FIG. 10 is a diagram for explaining error check cross-layer processing in the second embodiment. It is a block diagram which shows the structural example of the communication apparatus of one Embodiment of this invention.

(First embodiment)
The configuration of the communication apparatus according to this embodiment will be described. FIG. 1 is a block diagram illustrating a configuration example of a communication apparatus according to the present embodiment.

  As illustrated in FIG. 1, the communication device 100 includes a storage unit 190 and a control unit 180. The control unit 180 includes a CPU (Central Processing Unit) 182 that executes processing according to a program, and a memory 184 that stores the program. The memory 184 stores a program for executing a later-described cross layer access.

  FIG. 2 is a diagram showing an example of a protocol suite executed by the control unit shown in FIG. In the present embodiment, it is assumed that the protocol suite is an Internet protocol suite.

  The protocol suite shown in FIG. 2 is stored in the memory 184 in advance. The protocol suite may be stored in advance in the storage unit 190 instead of the memory 184. In this case, the protocol to be executed by the CPU 182 is read from the storage unit 190 to the memory 184. In FIG. 2, a plurality of protocols included in the protocol suite are classified into a plurality of hierarchical communication layers and displayed.

  The protocol suite has a link layer L001, an Internet layer L002, a transport layer L003, and an application layer L004.

  A wireless LAN (Local Area Network) protocol P110, a WiMAX (Worldwide Interoperability for Microwave Access) protocol P120, and an LTE (Long Term Evolution) protocol P130 belong to the link layer L001. IP P210 belongs to the Internet layer L002. TCP P310 and UDP P320 belong to the transport layer L003. The application layer L004 includes a moving image application software program (hereinafter referred to as “moving image application”) P410 and a Web application software program (hereinafter referred to as “Web application”) P420. A web browser is an example of a web application.

  As shown in FIG. 2, the communication layers are hierarchically configured so that only the adjacent communication layers can be accessed. For example, the application layer L004 can access the transport layer L003 but cannot directly access the Internet layer L002. The Internet layer L002 can access the transport layer L003 and the link layer L001, but cannot directly access the application layer L004.

  In the four communication layers shown in FIG. 2, the direction of processing flow from the lowermost layer to the uppermost layer is the upward direction, and the direction of processing flow from the uppermost layer to the lowermost layer is the downward direction.

  Note that an outline of TCP is disclosed in RFC 793 and an outline of UDP is disclosed in RFC 768. Therefore, detailed description of these protocols is omitted in this embodiment. Since the outline of IP is disclosed in RFC 791, detailed description thereof is omitted. An outline of the wireless LAN protocol is disclosed in IEEE 802.11, an outline of the WiMAX protocol is disclosed in IEEE 802.16e, and an outline of the LTE protocol is described in 3GPP Release. 8, detailed description of these protocols is omitted.

  The protocol suite shown in FIG. 2 is an example, and may include an application software program and a protocol different from those shown in FIG. 2 as long as the protocol suite includes a plurality of layered communication layers. .

  FIG. 3 is a functional block diagram showing a logical configuration realized by the CPU executing the protocol shown in FIG.

  The control unit 180 is classified into the moving image processing unit 410 and the Web application processing unit 420 classified into the application layer L004, the TCP processing unit 310 and the UDP processing unit 320 classified into the transport layer L003, and the Internet layer L002. It has an IP processing unit 210, a wireless LAN communication unit 110 classified as a link layer L001, a WiMAX communication unit 120, and an LTE communication unit 130.

  The moving image processing unit 410 is virtually configured when the CPU 182 executes the moving image application P410, and the Web application processing unit 420 is virtually configured when the CPU 182 executes the Web application P420.

  The TCP processing unit 310 is virtually configured when the CPU 182 executes TCP P310, and the UDP processing unit 320 is virtually configured when the CPU 182 executes UDP P320. The IP processing unit 210 is virtually configured by the CPU 182 executing the IP P210.

  The wireless LAN communication unit 110 includes a CPU 182 that executes the wireless LAN protocol P110 and a wireless LAN dedicated communication device. The WiMAX communication unit 120 includes a CPU 182 that executes the WiMAX protocol P120 and a WiMAX dedicated communication device. The LTE communication unit 130 includes an execution of the LTE protocol P130 by the CPU 182 and a communication device dedicated to LTE.

  The control unit 180 can communicate with another communication device by controlling each unit illustrated in FIG. 3 using the protocol suite illustrated in FIG. 2. In the following, in order to simplify the description, the protocol or program shown in FIG. 2 will be described as the main operation instead of the components shown in the functional block diagram of FIG.

  Here, a case where the communication apparatus 100 communicates with another communication apparatus will be briefly described. FIG. 4 is a schematic diagram showing an information processing method when two communication devices communicate with each other.

  The communication device 102 has the same configuration as the communication device 100.

  4 shows a state in which the wireless LAN protocol P110 in the link layer L001 directly communicates between the communication device 100 and the communication device 102, an access point (not shown) and a LAN (not shown) are used. A route may be used for communication that passes, and the communication form is not particularly limited. In addition, FIG. 4 shows a state in which applications in the application layer L004 are directly communicated between the communication device 100 and the communication device 102, but may also be via a server application (not shown). Other protocols are not limited to direct communication as in the above description.

  As shown in FIG. 4, information exchange is performed between the same protocols in the same communication layer. The solid line and broken line double arrows represent the exchanges between protocols in each communication layer. The application layer L004 will be described as an example. Data handled by the web application P420 is processed by the web application processing unit 420 of the communication apparatus 100, and data handled by the web application P421 is processed by the web application processing unit 420 of the communication apparatus 102. The As indicated by the solid double arrows, the data handled by the Web applications P420 and P421 is processed by the Web application processing units 420 of the communication device 100 and the communication device 102, respectively. In addition, as indicated by a broken-line bidirectional arrow, data handled by the moving image application P410 is processed by the moving image processing units 410 of the communication device 100 and the communication device 102, respectively.

  Actually, for example, when the communication apparatus 100 transmits data handled by the Web application P421 to the communication apparatus 102, the data passes through the application layer L004, the transport layer L003, and the Internet layer L002 of the communication apparatus 100 in order. Is transmitted from the link layer L001 to the communication apparatus 102. In the communication apparatus 102, the data received from the communication apparatus 100 reaches the application layer L004 via the link layer L001, the Internet layer L002, and the transport layer L003 in order, and is processed by the Web application processing unit 420. As a result, data processing for each communication layer is expressed as shown in the schematic diagram of FIG.

  The configuration of the control unit 180 related to normal operation has been described so far, but the configuration related to the cross-layer access function added to the communication apparatus 100 of the present embodiment will be described.

  First, cross-layer access will be described with reference to FIG. FIG. 5 is a diagram for explaining cross-layer access based on the protocol suite shown in FIG.

  In FIG. 5, the moving image application P410 receives information from the wireless LAN protocol P110, the WiMAX protocol P120 and the LTE protocol P130 in the link layer L001, the IP P210 in the Internet layer L002, and the TCP P310 in the transport layer L003. Is indicated by an upward broken arrow.

  Strictly speaking, the video application P410 accessing the TCP P310 does not correspond to cross-layer access because it exchanges information with the adjacent communication layer, but information exchange between each protocol with the adjacent communication layer However, in the following, it is referred to as cross-layer access, including cases other than normal exchanges defined in advance by the protocol.

  Information on each protocol includes, for example, quality information (number of retransmissions, signal power strength, etc.) in the wireless environment in the link layer L001, routing information and maximum packet size information in the Internet layer L002, and TCP in the transport layer L003. Information such as window size and number of retransmissions.

  Also, in FIG. 5, the moving picture application P410 uses this information to set an optimal TCP window size for the TCP P310 in the transport layer L003, or to select a line to be used in the link layer L001. The fact that it is possible to set parameters in the IP P210 in L002 is indicated by a downward dashed arrow.

  Similar to the video application P410, in FIG. 5, the Web application P420 includes the wireless LAN protocol P110, the WiMAX protocol P120 and the LTE protocol P130 in the link layer L001, the IP P210 in the Internet layer L002, and the transport layer L003. An upward arrow indicates that information can be acquired from each TCP P310. In addition, a downward arrow indicates that the Web application P420 can set parameters in the IP P210 in the Internet layer L002 in order to select a link layer link to be used.

  Next, configurations of the storage unit 190 and the control unit 180 for enabling execution of the cross-layer access described with reference to FIG. 5 will be described.

  The storage unit 190 stores a processing table for determining a protocol processing procedure executed by the control unit 180. FIG. 6A shows an example of an uplink processing table for determining an upstream processing procedure of the communication layer, and FIG. 6B shows an example of a downlink processing table for determining a downstream processing procedure of the communication layer.

  A plurality of types of processing procedures are registered in advance in each processing table, and each processing procedure is managed by a management number. As shown in FIGS. 6A and 6B, each processing table describes a protocol used in each communication layer corresponding to a management number. In the example shown in FIGS. 6A and 6B, (n + 1) types of processing procedures from 0 to n (n is an integer of 1 or more) are registered.

  Each of communication layers # 001 to 004 shown in each processing table corresponds to a link layer L001, an Internet layer L002, a transport layer L003, and an application layer L004.

  Referring to the uplink processing table in FIG. 6A, for example, in the processing procedure when the management number is 0, it is understood that the wireless LAN protocol P110 is used in the communication layer # L001 and the IP P210 is used in the communication layer # L002. The protocol used in the communication layer # L003 is “selectable”. This “selectable” indicates that a selection process defined in advance, that is, a protocol specified by a protocol number managed by the IP P210 is selected. The protocol used in the communication layer # L004 is also “selectable”. This indicates which application is selected with a port number managed in accordance with a predetermined selection process, that is, the protocol of the transport layer L003.

  In the upstream processing table of FIG. 6A, it can be seen that in the processing procedure when the management number is 2, the WiMAX protocol P120 is used in the communication layer # L001 and the moving image application P410 is used in the communication layer # L004. The protocol used in the communication layer # L002 is “NULL”. This “NULL” means that data including the message is passed to the next communication layer as it is without any processing in the communication layer. The protocol used in the communication layer # L003 is also “NULL”, which is the same as in the communication layer # 002.

  In this way, connection information between communication layers and mapping of processing operations of each communication layer are managed as a chain in communication units. Since a series of processes in a plurality of communication layers are determined in a chain form based on the management number, this series of processes is referred to as a chain. In addition, since the management number is a number for specifying a chain, the management number may be referred to as a chain number below.

  In the present embodiment, as shown in FIGS. 6A and 6B, processing tables are prepared separately for upstream and downstream, and (n + 1) types of processing procedures are managed with numbers from 0 to n. However, one table may be used as long as the protocol to be used can be specified according to each of the uplink and downlink cases. In addition, the identifier for specifying the processing procedure is not limited to the management number, and other identifiers may be used as long as the control unit 180 can specify the processing procedure, such as an address of a communication partner.

  In this embodiment, the management number for specifying the processing procedure is given by the protocol of the transmission source that wants to transmit information or control the protocol, and is included in a message that includes necessary information and control information. It may be attached to data received from 100 communication partners, and the method for obtaining the management number is not limited to these cases.

  When receiving data from an external device, the control unit 180 sets a management number by executing a protocol in the link layer L001. Then, in each communication layer higher than link layer L001, control unit 180 refers to the processing table shown in FIG. 6A to identify the chain corresponding to the management number, and executes processing according to the identified chain. Here, an example is shown in which the management number is always set when data is received. However, the management number may be assigned only when cross-layer processing is desired without changing the existing processing. In addition, a management number may be assigned when it is desired to transmit or control information according to necessity or request regardless of data reception.

  In addition, when transmitting data to an external device, the control unit 180 determines a management number by executing an application in the application layer L004 according to the type and format of the data. Then, the control unit 180 refers to the processing table shown in FIG. 6B in each communication layer lower than the application layer L004, identifies the chain corresponding to the management number, and executes processing according to the identified chain. , Attach a management number to the data and send it to an external device. Here, an example is shown in which a management number is always set when data is transmitted to an external device. However, a management number may be assigned when it is desired to transmit or control information according to necessity or request. .

  FIG. 7 is a flowchart showing a procedure for the control unit to determine a protocol in each communication layer. The control unit 180 receives data from an external device among the four communication layers shown in FIG. 2, and when the application receives data, the application is an external device from the link layer L001 to the application layer L004. 7 is performed for each communication layer from the application layer L004 to the link layer L001.

  Here, it is assumed that there are m (m is an integer of 1 or more) protocol types in each communication layer, and in FIG. 7, the protocol of the type k (k is an arbitrary integer of 1 to m) is “#k”. It is written. For example, referring to FIG. 5, m = 1 in the Internet layer L002 and m = 2 in the transport layer L003.

  In each communication layer, the control unit 180 refers to the processing table, and determines which protocol processing is to be performed on the data based on the information and the management number of the information processing target communication layer (step CF01). Subsequently, the control unit 180 executes the processing of the protocol determined in step CF01 on the data (steps CF02-1 to CF02-m). However, when the content specified in step CF01 is “NULL”, the control unit 180 does not process the data (step CF02− (m + 1)).

  Next, the operation of the communication apparatus 100 of this embodiment will be described.

  It is assumed that the communication device 100 has received data from an external device, and the control unit 180 refers to the processing table shown in FIG. 6A.

  FIG. 8 is a diagram for explaining the operation of the communication apparatus of this embodiment. FIG. 8 schematically shows processing for distributing information between adjacent communication layers in addition to the protocol processing in each communication layer of the protocol suite shown in FIG. Specifically, a communication layer interface for performing a communication layer distribution process is shown in the figure.

  Interfaces L012, L023, and L034 shown in FIG. 8 are added for easy understanding of processing between communication layers. The interfaces L012, L023, and L034 are virtually configured by the control unit 180 executing the process of step CF01 shown in FIG.

  Also, as shown in FIG. 8, an RSS (Receive Signal Strength) transmission function P111 is provided in the wireless LAN protocol P110, and it is set in advance to be effective when the management number is 2. And The RSS transmission function P111 is a function for transmitting the value of the received signal power intensity managed in the wireless LAN protocol P110 to the moving image application P410. With this function, for example, the moving image application P410 can use the value of the received signal power intensity for determination of moving image quality.

  First, with reference to FIG. 6A and FIG. 8, the case of the cross layer process (layer skip) which the communication apparatus 100 performs is demonstrated. Here, a case where the management number is 2 will be described.

  When the RSS transmission function P111 receives a wireless LAN frame from the outside, the RSS transmission function P111 reads information on received signal power intensity from the frame. Then, the RSS transmission function P111 sets the management number “2”, and transmits the received signal power strength data together with the message including the management number to the Internet layer L002, which is an upper layer, via the interface L012.

  When the interface L012 receives the received signal power strength data together with the message from the wireless LAN protocol P110 including the RSS transmission function P111, the interface L012 refers to the uplink processing table, identifies the chain based on the management number included in the message, and identifies Branch processing according to chain.

  In the uplink processing table shown in FIG. 6A, since the column of the communication layer # 002 when the management number is 2 is “NULL”, nothing is processed in the Internet layer L002. The interface L012 transmits the received signal power strength data including the message to the transport layer L003 via the interface L023 without passing it to the IP P210 in accordance with step CF02- (m + 1) shown in FIG.

  When the interface L023 receives the received signal power strength data including the message from the interface L012, the interface L023 refers to the uplink processing table, identifies the chain based on the management number included in the message, and branches the process according to the identified chain. .

  In the uplink processing table shown in FIG. 6A, the field of the communication layer # 003 when the management number is 2 is “NULL” as in the field of the communication layer # 002, so that no processing is performed even in the transport layer L003. . The interface L023 transmits the received signal power strength data including the message to the application layer L004 via the interface L034 in accordance with step CF02- (m + 1) shown in FIG.

  When the interface L034 receives the received signal power strength data including the message from the interface L023, the interface L034 refers to the uplink processing table, specifies the chain based on the management number included in the message, and branches the processing according to the specified chain. .

  In the uplink processing table shown in FIG. 6A, since the field of the communication layer # 004 when the management number is 2 is “P410”, the interface L034 transmits the received signal power strength data to the moving image application P410. When receiving the received signal power intensity data from the interface L034, the moving image application P410 uses the value for determining the moving image quality.

  When the management number is 2, as described above, the wireless LAN protocol P110 of the link layer L001 can transmit information to the moving image application P410 of the application layer L004. With such a processing procedure, it is possible to exchange information across communication layers with a common interface.

  Next, with reference to FIG. 6A and FIG. 8, the case of normal data packet processing executed by the communication apparatus 100 will be described. Here, the case where the management number is 0 will be described.

  When the wireless LAN protocol P110 in the link layer L001 receives a data packet from the outside, it performs normal data packet processing, sets a management number “0”, and sends the data packet together with a message including the management number to the upper layer. It transmits to the interface L012 addressed to the Internet layer L002.

  When the interface L012 receives the data packet together with the message from the wireless LAN protocol P110, the interface L012 refers to the uplink processing table, identifies the chain based on the management number included in the message, and branches the process according to the identified chain.

  In the uplink processing table shown in FIG. 6A, since the field of the communication layer # 002 when the management number is 0 is “P210”, the interface L012 transmits a data packet including a message to the IP P210. The IP P210 performs a predetermined process on the data packet received from the interface L012, and then transmits the data packet including the message to the transport layer L003 via the interface L023.

  When the interface L023 receives the data packet including the message from the IP P210, the interface L023 refers to the uplink processing table, specifies the chain based on the management number included in the message, and branches the process according to the specified chain.

  In the uplink processing table shown in FIG. 6A, the field of the communication layer # 003 when the management number is 0 is “selectable”, so the interface L023 cannot specify the destination protocol only by the management number. Therefore, the interface L023 refers to the protocol number described in the IP header to determine the destination protocol (transport layer protocol specifying process). Here, assuming that the protocol number is “6”, the interface L023 determines the transmission destination to be TCP P310 and transmits a data packet including a message to TCP P310. The TCP P310 performs a predetermined process on the data packet received from the interface L023, and then transmits the data packet including the message to the application layer L004 via the interface L034. Here, the interface L023 has been described in the case of analyzing the IP header. However, the interface L023 receives the result of the specific process of the above-described transport layer protocol that is normally performed in the IP P210, and branches the process according to the result. That is, it is possible to transmit a data packet including a message to TCP P310.

  When the interface L034 receives the data packet including the message from the TCP P310, the interface L034 refers to the uplink processing table, specifies the chain based on the management number included in the message, and branches the process according to the specified chain.

  In the uplink processing table shown in FIG. 6A, the field of the communication layer # 004 when the management number is 0 is “selectable” as in the case of the communication layer # 003. It can not be identified. Therefore, the interface L034 refers to the port number described in the TCP header and determines the destination protocol (application layer protocol specifying process). Here, assuming that the port number defined for the moving image application is “10000”, the interface L034 determines the transmission destination as the moving image application P410, and transmits a data packet including a message to the moving image application P410. When receiving the data packet from the interface L034, the moving image application P410 processes the data packet and displays the moving image on a display unit (not shown).

  Here, the interface L034 has been described in the case of analyzing the TCP header. However, the interface L034 receives the result of the specific process of the above-described application layer protocol normally performed in the TCP P310, and branches the process in accordance with the result. That is, it is possible to transmit a data packet including a message to the moving image application P410.

  When the management number is 0, normal protocol processing can be performed in hierarchical order instead of the cross layer. An existing data packet can be delivered to the application by such a processing procedure.

  In the above description of the operation, the expression “transmits data” between the interface and the protocol. However, in actuality, the interface and protocol store the data in the storage unit 190 and indicate the data storage location ( For example, addresses may be exchanged with each other. Although an example of processing in the upstream direction is shown here, the processing in the downstream direction can be realized in the same manner, and detailed description thereof is omitted.

  Next, the effect of the information processing method by the communication apparatus 100 of this embodiment is demonstrated.

  In this embodiment, information exchanged between each communication layer is defined as an event, and the operation of each communication layer is expressed by an event model including elements of event reception, event processing, and event transmission. Mapping of processing operations of each communication layer is managed as a chain in communication units. Then, when crossing the communication layers, the chain is referred to, and the processing within each communication layer is branched to allow free access between the communication layers.

  Therefore, each communication layer operates independently as an event model, and processing of multiple communication layers is comprehensively optimized. Therefore, even in an environment where multiple applications operate and can be freely replaced, it is useless. It is optimized as a whole without processing. The event is, for example, information on a message including a management number and data to be processed.

  Further, when adding cross-layer processing, it has wide expandability and portability without increasing the interfaces of each communication layer. The reason is that a cross-layer process is added to each communication layer, and the process can be organized and defined and used in common and can be used in common.

  Furthermore, even in an environment in which a plurality of applications operate and can be freely replaced, information can be transmitted to each communication layer in units of application communication processing. For example, when a disconnection event occurs in the link layer, it is possible to quickly notify the communication processing of the application. The reason for this is that chain-managed cross-layer access is provided, so that each protocol can manage chain usage, refer to the destination of the chain in use, and broadcast to multiple applications according to the chain. This is because one application can be notified.

  Note that the protocol processing of each communication layer and the processing of step CF01 (corresponding to the interface of FIG. 8) shown in FIG. 7 may be executed by separate hardware. For example, a dedicated integrated circuit corresponding to each protocol may be provided, and the CPU 182 may execute only interface processing. The same applies to the second embodiment.

(Second Embodiment)
In the present embodiment, the processing executed in each communication layer enables selection in units of functions included in the protocol.

  A configuration of the communication apparatus 100 according to the present embodiment will be described. In the present embodiment, differences from the first embodiment will be described in detail, and a detailed description of the same configuration as that of the first embodiment will be omitted.

  FIG. 9 is a diagram for explaining a protocol suite in this embodiment. FIG. 9 schematically shows in detail the functions included in each protocol based on the protocol suite shown in FIG.

  As shown in FIG. 9, the moving image application P410 has functions F411 to F415. The Web application P420 has functions F431 to F423. TCP P310 has functions F311 to F314. The UDP P320 has functions F321 to F323. The IP P210 has functions F211 to F215. The wireless LAN protocol P110 has functions F111 to F114. The WiMAX protocol P120 has functions F121 to F123.

  Next, how the control unit 180 in this embodiment manages and executes functions included in the protocol will be described. FIG. 10 is a flowchart showing a procedure for executing a function in the protocol by the control unit.

  Functions F121 to F423 in the protocol can be expressed by a collection of processing flows as shown in FIG. 10, for example. That is, it can be considered that the protocol is configured by executing one or more steps in the processing flow shown in FIG. In this embodiment, as shown in FIG. 10, each function in the protocol is classified into an event model including elements of event reception processing A001, event processing A002, and event transmission processing A003, so that each function can be easily managed. doing.

  FIG. 10 shows a case where event reception processing A001, event processing A002, and event transmission processing A003 are performed in order. The control unit 180 executes event processing following the event reception processing within a certain protocol. However, depending on the function, the event transmission processing may not be performed thereafter. Moreover, although the control part 180 performs an event reception process, you may perform an event transmission process, without performing an event process.

  Next, the configuration of the processing table stored in the storage unit 190 will be described.

  The storage unit 190 stores a processing table for determining a protocol processing procedure executed by the control unit 180. FIG. 11 shows an example of an upstream processing table for determining the upstream processing procedure of the communication layer.

  A plurality of types of processing procedures are registered in advance in the processing table, and each processing procedure is managed by a management number. As shown in FIG. 11, the processing table describes functions used in each communication layer corresponding to the management number. In the example shown in FIG. 11, (n + 1) types of processing procedures with management numbers 0 to n (n is an integer equal to or greater than 1) are registered.

  Referring to the uplink processing table in FIG. 11, for example, in the processing procedure when the management number is 0, a chain that uses the functions F111 to F113 in the wireless LAN protocol P110 is defined in the communication layer # L001. In the communication layer # L002, a chain using the functions F211 to F215 in the IP P210, in the communication layer # L003, a chain using the functions F311 to F314 in the TCP P310, and in the communication layer # L004, a function F411 in the video application P410. A chain using ~ F414 is defined.

  In this way, in this embodiment, not only the connection information between communication layers and the processing operation of each communication layer, but also which function is used in sequence within the protocol of each communication layer is managed as a chain.

  In the present embodiment, the configuration of the upstream processing table has been described. However, the downstream processing table is the same as the table shown in FIG. 11, and detailed description thereof is omitted.

  Further, as in the first embodiment, the processing table is described as being prepared separately for uplink and downlink. However, if a function to be used can be specified according to each case of uplink and downlink, the table is a single table. Also good. In addition, the identifier for specifying the processing procedure is not limited to the management number, and other identifiers may be used as long as the control unit 180 can specify the processing procedure, such as an address of a communication partner.

  Next, the operation of the communication apparatus 100 of this embodiment will be described.

  It is assumed that the communication device 100 has received data from an external device, and the control unit 180 refers to the processing table shown in FIG. Here, a case where the management number is 1 will be described.

  When the management number is 1, as shown in FIG. 11, it can be seen that this is an uplink chain that uses the functions F113, F114, and F415. Here, the interface between the communication layers is the same as that shown in FIG.

  In the function F114, use of a chain having a management number of 1 is set in advance. Alternatively, the function F114 may specify a chain by searching the processing table. In the case of specifying a chain by searching, the function F114 refers to the processing table when executing the operation and searches for a chain in which the communication layer # L001 has its own number F114. As a result of the search, the function F114 can recognize that the chain whose management number is 1 is used from the processing table shown in FIG.

  When the communication apparatus 100 receives data from the outside via the wireless LAN protocol P110, the wireless LAN protocol P110 causes the function F114 to execute processing. The function F114 refers to the chain with the management number “1” in the process table and causes the function F113 to execute the process. When the function F113 receives the data from the function F114, the function F113 transmits the data together with the message including the management number to the Internet layer L002, which is an upper layer, via the interface L012, after executing the process.

  When the interface L012 receives the data together with the message from the function F113, the interface L012 refers to the uplink processing table, identifies the chain based on the management number included in the message, and performs processing according to the identified chain.

  In the uplink processing table shown in FIG. 11, the column of the communication layer # 002 when the management number is 1 is “NULL”, so nothing is processed in the Internet layer L002. The interface L012 transmits data including the message to the transport layer L003 via the interface L023.

  When the interface L023 receives data including a message from the interface L012, the interface L023 refers to the uplink processing table, specifies a chain based on the management number included in the message, and performs processing according to the specified chain.

  In the uplink processing table shown in FIG. 11, the communication layer # 003 column when the management number is 1 is “NULL” as in the communication layer # 002 column, so no processing is performed even in the transport layer L003. . The interface L023 transmits data including the message to the application layer L004 via the interface L034.

  When the interface L034 receives data including a message from the interface L023, the interface L034 refers to the uplink processing table, specifies a chain based on the management number included in the message, and performs processing according to the specified chain.

  In the uplink processing table shown in FIG. 11, since the field of communication layer # 004 when the management number is 1 is “function F415”, the interface L034 transmits data to the moving image application P410. When receiving the data from the interface L034, the moving image application P410 causes the function F415 to execute processing. With such a processing procedure, it is possible to exchange information across communication layers with a common interface, and to perform processing across communication layers.

  In the processing table shown in FIG. 11, the chain with the management number n is compared with the chain with the management number 0. When the management number is n, the function F112, the function F212, the function F213, the function F214, the function F312 and the function F313 are skipped by “NULL” from the chain of the communication layer # L001 to the communication layer # L003 when the management number is 0 You can see that

  In this way, in the present embodiment, it is possible to easily realize processing for skipping some functions in the protocol.

  Although omitted here, by setting “selectable” in the function setting column in the processing table shown in FIG. 11, it is possible to continue processing for the protocol of the next communication layer specified in each function. It is.

  Hereinafter, an example of functions included in the protocol and a specific example in the case of skipping part of the processing of the protocol functions will be described.

  This embodiment is a case of session setting processing in TCP.

  When an application function makes a system call for starting communication to an OS (Operating System), a TCP session setting function is selected. The session setting function performs a process of transmitting a SYN packet to a communication partner and receiving an Ack packet, or a process of receiving a SYN packet from the partner and transmitting an Ack packet. This is a flow when an application starts a TCP session, and is realized by a chain in the processing table.

  Here, if the communication device only needs a one-to-one session, that is, if the communication device has only one application and only one session is required, communication is performed using a predetermined port number immediately after the power is turned on. Therefore, the TCP SYN process is not necessary. In order to realize this, since the session setting function is unnecessary, it is only necessary to skip using a chain in the processing table.

  This embodiment is a case of window control in TCP.

  In TCP, the number of octets that can be received by the receiving side is entered in the WINDOW field of the Ack header transmitted from the receiving side. The transmitting side transmits the data size not exceeding the number of octets next time. Generally, since the transmission quality between communication devices is unknown at the start of TCP communication, the receiving side returns Ack to the transmitting side with the initial number of octets being small. Only when the transmission quality is judged to be good by the checksum check of the packet sent from the transmission side after that, the reception side returns Ack with the value of the WINDOW field increased. As a result, the transmission side Data containing a larger number of octets will be sent.

  Here, if the receiving side knows that the transmission quality is good from the beginning and the buffer size on the receiving side is sufficiently prepared, the receiving side increases or decreases the value of the WINDOW field every time a TCP packet is received. It is not necessary to perform the checksum processing of the received packet by using the chain in the processing table, and a predetermined large fixed value may be set in the WINDOW field.

  Should a failure occur in the transmission path between communication devices, for example, the receiving side refers to the value obtained from the error detection function of the link layer, performs accumulation and statistical processing, and the value is a predetermined threshold value. Only when the value exceeds, the value of the WINDOW field should be reduced by an appropriate number of octets. By doing so, it is possible to perform high-speed TCP communication with a low processing amount from the communication start time.

  On the other hand, when the receiving side knows that the transmission quality is poor from the beginning, the effect obtained by performing the WINDOW control is small. Therefore, if the receiving side sets a small number of octets in the WINDOW field from the beginning and skips WINDOW control using the chain in the processing table, TCP communication can be performed with low processing. . In other words, by omitting the WINDOW control that can only slightly increase / decrease the WINDOW field, it becomes possible to share many TCP processes performed between communication apparatuses.

  Next, error check cross-layer processing will be described with reference to FIG.

  FIG. 12 describes functions in the protocol suite shown in FIG. 9 while focusing on error check processing.

  The wireless LAN protocol P110 in the link layer L001 has a WLAN error check function F112 that performs a packet error check. Specifically, when the communication apparatus 100 receives a wireless LAN packet, the WLAN error check function F112 determines whether the CRC field value in the packet is equal to a CRC (Cyclic Redundancy Check) calculated from the entire packet. The function is to confirm and basically discard the packet if the values do not match.

  Further, the IP P210 of the Internet layer L002 has an IP error check function F214 that performs packet error check. Specifically, the IP error check function F214 calculates the one's complement of the one's complement sum for the IP header portion in the packet, and checks the error by comparing it with the checksum value.

  Similar to IP, TCP has a TCP error check function F312 that performs packet error check. Specifically, the TCP error check function F312 is a process of calculating the one's complement of the one's complement sum for the TCP header and payload portion in the packet.

  Here, although the IP error check function F214 and the TCP error check function F312 are different in their objects, the processing contents are the same. Therefore, for example, the IP error check function F214 may be used instead of the TCP error check process F312 defined in the process table. That is, if it is specified in the processing table that the IP error check function F214 is executed instead of the TCP error check function F312, the TCP error check function F312 can be replaced with the IP error check function F214. By doing in this way, common processes within each protocol can be collected.

  According to the present embodiment, in addition to the effects described in the first embodiment, the following effects can be obtained.

  In the present embodiment, whether or not the protocol function is used can be freely determined by the event and the chain. For example, cross-layer access that skips the communication layer or processing that skips a part of the functions of the communication layer can be performed simply by expressing “NULL” on the chain.

  In addition, the use of functions in the protocol, the processing order, and the like can be freely changed according to events and chains. For example, it is easy to execute a full set of protocols, execute only a part of the protocol, or combine different functions to execute new protocol functions.

  Furthermore, common processing among the functions in the protocol can be specified and used in each protocol by the chain. For example, it is not necessary to prepare calculation processing such as encryption processing and data error check processing using individual protocols.

  In the above-described embodiments and examples, the configuration and operation have been specifically described in order to easily understand the communication device of the present invention. However, the communication device of the present invention has at least the following features.

  FIG. 13 is a block diagram illustrating a configuration example of a communication apparatus according to an embodiment of the present invention.

  As illustrated in FIG. 13, the communication apparatus 101 according to the embodiment of the present invention includes a control unit 180. When the controller 180 transmits / receives data to / from an external communication device via a plurality of hierarchical communication layers, the control unit 180 defines information exchanged between the communication layers as an event, and the protocol processing operation of each communication layer It is managed by an event model consisting of elements such as event reception, event processing, and event transmission, and processing is executed in units of event models. The control unit 180 exchanges data between communication layers and executes protocol processing in each communication layer in units of event models, and if event transmission is specified after event reception in a certain communication layer, the communication is performed. Cross-layer processing for transferring data to the next communication layer without performing protocol processing in the layer becomes possible.

  The communication control method of the present invention belongs to the field of telecommunications and is applied to the field of communication systems that use a communication layer (protocol stack / suite) to process transmitted and / or received information. Is possible.

100, 101 Communication device 180 Control unit 190 Storage unit

Claims (6)

A memory storing a table describing functions included in the protocol for managing protocol processing operations in a plurality of hierarchical communication layers by an event model including elements of event reception, event processing, and event transmission And
When transmitting / receiving data to / from an external communication device via the plurality of hierarchical communication layers, information exchanged between each communication layer is defined as an event, and the protocol processing operation of each communication layer is defined by the event model. And managing the connection information between each communication layer and the mapping of processing operations of each communication layer as a chain by communication unit using the table, and referring to the table when receiving the event, according to the chain A communication apparatus having a control unit that determines and executes which function to use among functions included in a protocol in a layer. The communication device according to claim 1.
The controller is
A communication device that determines which protocol to use among protocols included in each communication layer according to the chain with reference to the table when the event is received. The communication device according to claim 1 or 2,
The controller is
A communication device that uses the same processing content among the functions of the protocol in each communication layer in accordance with the chain, and is commonly used for different objects. The communication device according to claim 1.
The controller is
A communication apparatus that skips processing operations of one or more communication layers among the plurality of communication layers according to the chain with reference to the table when the event is received. A memory storing a table describing functions included in the protocol for managing protocol processing operations in a plurality of hierarchical communication layers by an event model including elements of event reception, event processing, and event transmission A communication control method by a communication device having a unit,
When transmitting / receiving data to / from an external communication device via the hierarchical communication layers, information exchanged between the communication layers is defined as an event.
Manage the processing operation of each communication layer protocol with the event model,
Using the table, the connection information between the communication layers and the mapping of processing operations of the communication layers are managed as a chain in communication units, and when the event is received, the table is referred to according to the chain according to the chain. A communication control method that determines and uses which of the functions included in the protocol is used. A memory storing a table describing functions included in the protocol for managing protocol processing operations in a plurality of hierarchical communication layers by an event model including elements of event reception, event processing, and event transmission A computer having a
A procedure for defining information exchanged between each communication layer as an event when transmitting / receiving data to / from an external communication device via the plurality of hierarchical communication layers;
A procedure for managing the processing operation of each communication layer protocol by the event model,
Using the table, the connection information between the communication layers and the mapping of processing operations of the communication layers are managed as a chain in communication units, and when the event is received, the table is referred to according to the chain according to the chain. A program for causing a computer to execute a procedure of determining and executing which function is used among functions included in a protocol.

Images