KR101473868B1 - A node and a method of communicating among a plurality of nodes in content-centric networking environment - Google Patents

Abstract

A method and a node for communicating between nodes in a content-centric network environment are provided. More particularly, according to the method for communicating between nodes in a content-centric network environment, a portion of nodes among nodes constituting a network is selected so that an interest message and a data message are transferred intensively through the relay node, and a publisher relay node is selected among the relay nodes so that only the publisher relay node generates and broadcasts a multi-hop content announce message flooding through the entire network. Thus, efficient communication and improving a network performance can be achieved.

Description

[0001] The present invention relates to a method and a node for communicating between nodes in a content-based networking environment,

TECHNICAL FIELD OF THE INVENTION The present invention relates to a communication method and node between nodes in a content-oriented networking environment, and more particularly, to a communication method and node between nodes in a content-based networking environment that enables efficient communication.

Since the Internet Protocol (IP) -based host-centric networking technology, which is the basis of the current Internet, does not meet the explosive growth of Internet traffic due to the increase in the demand for video contents service, a new networking architecture is used for content-centric networking ) Technology has been proposed.

The content-oriented networking technology uses the content name itself as an address for networking, rather than an Internet address that indicates the location of the host device, due to the fact that the main purpose of the Internet is to request and distribute content in order to efficiently process traffic. So that the user can get the desired content from the nearest place. The content-centric networking technology avoids the inefficiency of data repetitive transmission due to the caching of the nodes constituting the network without requiring end-to-end connectivity and avoids the problem of routing loops And is emerging as a new networking architecture.

In recent years, due to the rapid spread of mobile terminals such as a smart phone, a user's Internet access environment is shifted to a moving center, and not only a wired environment in which nodes constituting a network are fixed, but also a content provider has mobility, Researches have been actively conducted to realize the feature of the content-oriented networking technology in a mobile ad-hoc network in which the mobile terminal can have mobility.

Patent Publication No. 2013-0080626

The technical object of the present invention is to provide a communication method and node between nodes in a content-oriented networking environment that reduces broadcast overhead between nodes and enables efficient delivery of content information and data .

According to an aspect of the present invention, there is provided a method for communicating between nodes in a content-based networking environment, the method comprising: a plurality of nodes each having at least one relay Selecting one of the selected relay nodes as a publisher relay node, determining whether each of the selected relay nodes is a publisher relay node, and determining whether the determined relay node has content information of its own one- Generating a multi-hop content announce message including the multi-hop content announcement message, and broadcasting the multi-hop content announcement message to the plurality of nodes via the selected relay nodes.

A node implementing a content-centric networking environment according to another aspect of the present invention includes a topology information storage unit for storing topology information on neighboring neighboring nodes within two hops from the topology information storage unit, And a relay node selecting unit for selecting at least one relay node among the hop neighboring nodes.

In a content-centric networking environment according to the present invention, a method and a node for communicating between nodes select some nodes among the nodes constituting the network as relay nodes so that an inter- So that channel congestion and collision can be prevented.

Also, by selecting a publisher relay node among the relay nodes, and generating and broadcasting a multi-hop content announcement message in which only the publisher relay node is flooded to the entire network, the broadcast overhead of the network is reduced .

BRIEF DESCRIPTION OF THE DRAWINGS A brief description of each drawing is provided to more fully understand the drawings recited in the description of the invention.
FIGS. 1A to 1H are conceptual diagrams sequentially illustrating networks to which a communication method between nodes in a content-based networking environment according to an embodiment of the present invention is applied.
FIG. 2 is a flowchart illustrating a method of communicating between nodes in a content-based networking environment according to an embodiment of the present invention.
FIG. 3 is a flowchart illustrating a process of selecting a relay node in FIG. 2 according to an embodiment of the present invention.
FIG. 4 is a flow chart for explaining a step of selecting a publisher relay node in FIG. 2 according to an embodiment of the present invention.
FIG. 5 is a functional block diagram of a node implementing a content-oriented networking environment according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals are used for the same constituent elements in the drawings, and a duplicate description thereof will be omitted.

Embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The present invention is not limited to the following embodiments. Rather, these embodiments are provided so that this disclosure will be more thorough and complete, and will fully convey the concept of the invention to those skilled in the art.

In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The terminologies used herein are terms used to properly represent embodiments of the present invention, which may vary depending on the user, intent of the operator, or custom in the field to which the present invention belongs. Therefore, the definitions of these terms should be based on the contents throughout this specification. Like reference symbols in the drawings denote like elements.

In a content-centric networking environment, a bi-directional transmission of interest and data is used. That is, in the content-oriented networking environment, when a node capable of providing a node, for example, caching, transmits an inter- est (i.e., a request or query) message based on a name of a desired content, A content request-to-content transmission "scheme is used in which data including the content is transmitted to the node that requests the content.

In the case where the content-centric network environment is implemented in a mobile ad-hoc network (MANET) autonomously configured between dynamically changing nodes without the help of a fixed network, All types of messages are delivered to all nodes in a broadcast fashion. That is, all types of messages flood through each node and propagate to all nodes.

Due to the broadcast nature of the MANET, when the content-centric networking environment is implemented in the MANET, as each node participates in the message retransmission, the channel contention and collision probability increases and the overall network performance may be degraded.

The present invention relates to a communication method and node between nodes in a content-oriented networking environment for solving the above problems, and embodiments of the present invention will be described below on the assumption that a content-oriented networking environment is implemented in a MANET. However, it is to be understood that the technical idea of the present invention can be applied to a network other than the MANET.

FIGS. 1A to 1H are conceptual diagrams sequentially illustrating networks to which a communication method between nodes in a content-based networking environment according to an embodiment of the present invention is applied. 1A-1H, the network is shown as consisting of nodes 0 through 10, but is not so limited, and the network may have a greater number of nodes. The nodes 0 to 10 may be devices that have a wireless interface and can satisfy the mobile computing function of the host and the routing function of the router at the same time. Nodes 0-10 may be devices such as mobile phones, notebooks, tablet PCs, PDAs, or mobile devices with sensors, for example.

Referring to FIG. 1A, each of nodes 0 to 10 transmits its content announcement (CA) message to a one-hop neighboring node and transmits a CA message of the one-hop neighboring node . Taking the case of node 0 as an example, node 0 sends its CA message to nodes 1 and 4, and receives CA messages of nodes 1 and 4 from nodes 1 and 4, respectively. At this time, the CA message has a flooding range limited to one hop.

The CA message may include information on a node that transmits the CA message and information on a one-hop neighbor node of the node that transmits the CA message. For example, the CA message includes content information (Content Prefix), identification information (ID), cache hit ratio information (Cache-hit Ratio), node type information (Type) (HOP Count), and message type information (CA Type).

The content information (content prefix) is information on the content stored in the corresponding node, and may include, for example, a content name, a name of a provider, and the like. The identification information (ID) may be information for distinguishing nodes, and may be a MAC address, for example. Cache-hit ratio information is information indicating how often its content is referenced by other nodes, and may be information including the total number of content requests in the network and the ratio of the number of content replies . The node type information (Type) may be information for distinguishing whether the node is a relay node. The hop count information (HOP Count) may be information on the number of hops that the CA message has been forwarded through the nodes. The message type information (CA Type) may be information for distinguishing whether the flooding range of the CA message is one hop or more than two hops (i.e., a multi-hop CA message).

The CA message includes a contents information list (Neighbor Content Prefix List), an identification information list (Neighbor ID List), and a node type information list (Neighbor Type List) of the one-hop neighboring node of the node transmitting the CA message . That is, the CA message may include content information, identification information, and node type information of the listed 1-hop neighbor node.

The CA message may be arbitrarily generated by a node that transmits the CA message. For example, as shown in FIG. 1 (e)), in order to notify each node of the result of selecting a relay node from its one-hop neighboring node, a relay selected from a node type information list (Neighbor Type List) It is possible to generate a CA message by changing the node type of the node to the relay node. However, the present invention is not limited thereto, and the CA message may be generated in a predetermined cycle.

Each of the nodes 0 to 10 generates topology information based on the CA message received from the one-hop neighboring node, and stores the topology information.

The topology information may be information on a neighboring node within two hops from the node itself. For example, the topology information may include one hop neighbor node information of the corresponding node and two-hop neighbor node information connected through the one-hop neighbor node. The one-hop neighbor node information may include content information, identification information, and cache hit rate information of a node that transmits the CA message. The two-hop neighboring node information may include a content information list, an identification information list, and a type information list of the one-hop neighboring node of the node transmitting the CA message. The topology information may be updated each time the node receives a CA message.

In the case of node 0, for example, node 0 receives information about nodes 1 and 4, which are one hop neighbor nodes, and information about nodes 2 and 3, which are two hop neighbor nodes, based on CA messages of nodes 1 and 4 received from nodes 1 and 4 , ≪ / RTI > 7, and 10, respectively.

Referring to Figs. 1B-1D, each of nodes 0 to 10 selects at least one relay node among its one-hop neighbor nodes based on its topology information. The relay node is a node for intensively flooding an intra message and a data message transmitted from a node selected by the relay node to the other nodes without being flooded.

The relay node selection process will be described in more detail. First, nodes 0 to 10 respectively calculate MPRcost of its own 1-hop neighboring node and select a node having the largest MPRcost among its 1-hop neighboring nodes as the relay node do.

The MPRcost may be expressed by Equation (1).

In Equation (1), i denotes an i-th one-hop neighbor node of a specific node (any one of nodes 0 to 10). 2hRatio (i) represents a ratio between the number of two-hop neighbor nodes of the specific node and the number of one-hop neighbor nodes of the i-th one-hop neighbor node of the specific node. CachehitRatio (i) represents the number of content requests of the entire network and the content reply rate of the i-th one-hop neighbor node of the node. and? represents a weighting factor. α may be greater than or equal to 0 and less than or equal to 1, such that MPRcost may be computed based on at least one of 2hRatio (i) and CachehitRatio (i).

Then, each of the nodes 0 to 10 removes information about the two-hop neighbor node connected through the selected relay node in its topology information. That is, each of the nodes 0 to 10 stores information about a two-hop neighbor node connected through the selected relay node in a content information list for two-hop neighbor nodes included in its topology information, an identification information list, Lt; / RTI >

Each of the nodes 0 to 10 repeats the relay node selection process described above until the information about the two-hop neighboring node is completely removed from its topology information.

The relay selection process will be described by taking the case of node 0 in FIG. 1B, which shows the result of selecting relay nodes of nodes 0, 2, 7 and 9 as an example. In the description of FIG. 1B, it is assumed that MPRcost of nodes 1 and 4 is calculated based on only 2hRatio (.alpha. = 0) for convenience of explanation. 1C and 1D.

Node 0 yields MPRcost for nodes 1 and 4, which are one hop neighbor nodes. The number of 2-hop neighbors in node 0 is 4 (nodes 2, 3, 7, and 10), the number of 1-hop neighbors in node 1 is 2 (nodes 2 and 10) Nodes 3, 7 and 10), MPRcost of node 1 is 2/4 and MPRcost of node 4 is 3/4.

Node 0 selects node 4 having the largest MPRcost as a relay node and removes information about two-hop neighbor nodes (nodes 3, 7, and 10) connected through node 4 in the topology information.

Node 0 selects the relay node again because there is information about node 2 among 2-hop neighbor node information in the topology information. Node 0 selects node 1, which is a one-hop neighbor node, as a relay node, and removes information on node 2 from the two-hop neighbor node information in the topology information.

Similarly, node 2 selects nodes 1 and 5 as relay nodes, node 7 selects nodes 4 and 8 as relay nodes, and node 9 selects nodes 5 and 8 as relay nodes. Nodes 2, 7, and 9 all remove information about the two-hop neighboring node from their topology information.

A different relay selection process will be described taking the case of node 1 as an example in FIG. 1C showing the relay node selection results of nodes 1, 4, 5, and 8 as an example.

Node 1 computes the MPRcost of nodes 0, 2, and 10, which are one hop neighbor nodes. The number of two-hop neighbors in node 1 is 3 (nodes 4, 5, and 8), the number of 1-hop neighbor nodes in node 0 is 1 (node 4), the number of 1-hop neighbor nodes in node 2 is 1 , MPRcost of node 0 is 1/3, MPRcost of node 2 is 1/3, and MPRcost of node 10 is 1, since the number of neighbor nodes of node 10 is 3 (nodes 4, 5, and 8).

Node 1 selects node 10 having the largest MPRcost as a relay node and removes information about two-hop neighbor nodes (nodes 4, 5, and 8) connected through node 10 in the topology information.

The node 10 does not additionally select a relay node because the information about the two-hop neighboring node is completely removed from the topology information.

Likewise, nodes 4, 5, and 8 also select node 10 as a relay node, and remove information about two-hop neighboring nodes from topology information, respectively.

Another relay selection process will be described by taking as an example the case of node 3 in FIG. 1D showing the relay node selection result of nodes 3 and 6.

Since node 3 has only one node as its one-hop neighbor node, node 4 is selected as a relay node, and information about nodes 2, 7, and 10, which are two-hop neighbor nodes, is removed from the topology information. Similarly, node 6 selects node 5 as a relay node and removes information about nodes 2, 9, and 10, which are two-hop neighbor nodes, in the topology information.

Referring to FIG. 1E, each of nodes 0 to 10 transmits a CA message reflecting a relay node selection result to its one-hop neighboring node. Specifically, each of the nodes 0 to 10 generates a CA message in which the node type information of the selected relay node is changed in the node type information list (Neighbor Type List) of its one-hop neighbor node, To one hop neighbor node. Each of the nodes 0 to 10 receives a CA message reflecting the relay node selection result of its own 1-hop neighbor node from its own 1-hop neighboring node. Here, as in the case of the CA message described in FIG. 1A, the CA messages reflecting the relay node selection result are limited to one hop in the flooding hop range.

Each of the nodes 0 to 10 can check the CA message received from its one-hop neighboring node and update its node type information (Type). In addition, each of the nodes 0 to 10 can retransmit the CA message received from the node selected as the relay node to the node selected as the relay node itself.

Thus, as the interrest and data messages in the network are not flooded by all of nodes 0-10, but are flooded by nodes 1, 4, 5, 8 and 10 selected as relay nodes, The probability of interference, congestion and collision in the network at the time of transmission can be reduced. Therefore, the performance of the network can be improved.

Referring to FIG. 1F, nodes 1, 4, 5, 8, and 10 selected as relay nodes among the nodes 0 to 10 respectively determine whether they are the publisher relay nodes. The publisher relay node is a node for preventing all nodes from broadcasting a CA message to the entire network. Wherein the publisher relay node generates a multi-hop CA message including content information of its own one-hop neighbor node and broadcasts the multi-hop CA message to the entire network on behalf of the one- to be. Similar to the CA message illustrated in FIGS. 1A and 1E, the multi-hop CA message includes information on a node that transmits the multi-hop CA message and information on a single-hop neighbor node of the node that transmits the multi- . The multi-hop CA message differs from the CA message described in FIGS. 1A and 1E in that the message type information (CA type) indicates two or more hops.

The publisher relay node determination process will be described in more detail. First, nodes 1, 4, 5, 8, and 10 selected as relay nodes determine whether there is a node selected as a relay node among their one-hop neighbor nodes.

Each of the nodes 1, 4, 5, 8, and 10, if there is another node selected as the relay node among the one-hop neighbor nodes of its own, The number of neighboring nodes is compared, and when the number of one-hop neighboring nodes of the node is equal to or greater than the number of one-hop neighboring nodes of another node selected as the relaying node, the relaying node determines itself as a publisher relaying node. Each of the nodes 1, 4, 5, 8, and 10 determines itself as a publisher relay node if there is no other node selected as the relay node among its one-hop neighboring nodes. Each of the nodes 1, 4, 5, 8, and 10 can compare the number of one-hop neighboring node with another node selected as the relay node based on its own topology information.

The relay node determined as the publisher relay node generates the multi-hop CA message by changing the message type information (CA type) in its CA message, and transmits the multi-hop CA message to all the nodes constituting the network through the adjacent relay nodes Broadcast the CA message.

Describing the publisher relay node determination process using, for example, node 1, node 4, node 5, node 8, and node 10 selected as relay nodes, node 4 has node 10 selected as a relay node among the one-hop neighbor nodes. Node 4 determines itself as a publisher node because its number of one-hop neighboring nodes is equal to the number of one-hop neighboring nodes of node 10. Node 5 similarly determines itself as the publisher relay node.

Describing another publisher relay node determination process, for example, node 1, node 4, node 5, node 8, and node 10 selected as relay nodes, node 1 has node 10 selected as a relay node among the one-hop neighbor nodes. Node 1 does not determine itself as a publisher node because its number of one-hop neighboring nodes is smaller than the number of one-hop neighboring nodes of node 10. Node 8 does not similarly determine itself as a publisher relay node.

Describing another publisher relay node determination process, for example, node 1, node 4, node 5, node 8, and node 10 selected as relay nodes, node 10 has all the one-hop neighbor nodes selected as relay nodes. Node 10 determines itself as a publisher relay node because its number of one-hop neighboring nodes is greater than the number of one-hop neighboring nodes of nodes 1 and 8 and equal to the number of one-hop neighboring nodes of nodes 4 and 5, respectively.

The determined publisher relay nodes 4, 5, and 10 each generate a multi-hop CA message and broadcast the multi-hop CA message to all nodes of the network via neighboring relay nodes. It is of course that the determined publisher relay nodes 4, 5 and 10 can transmit the multi-hop CA message to neighboring normal nodes.

On the other hand, the relay nodes 1 and 8 not selected as the publisher relay node can determine themselves as the publisher relay node when they do not receive the multi-hop CA message including their content information for a predetermined time. That is, when the relay nodes 1 and 8 do not receive the multi-hop CA message including their content information, the relay nodes 1 and 8 generate the multi-hop CA message by changing the message type information (CA type) , And broadcasts the generated multi-hop CA message to all the nodes constituting the network through adjacent relay nodes. Thus, the content information of each node in the network can be accurately maintained.

FIG. 1G shows a case where the publisher relay node 5 broadcasts a multi-hop CA message. Referring to FIG. 1G, a multi-hop CA message generated and broadcast by the publisher relay node 5 may be delivered to the normal nodes 0, 3, and 7 via the relay nodes 10 and 4. The multi-hop CA message may be delivered to the normal node 1 or 2 via the relay nodes 10 and 1. The multi-hop CA message may be delivered to the node 7 or 9 via the relay nodes 10 and 8. The multi-hop CA message may be passed directly to the normal nodes 2, 6 and 9. Likewise, a multi-hop CA message generated and broadcast by the publisher relay nodes 4 and 10 may be delivered to all nodes of the network.

In this way, not all the nodes constituting the network broadcast the CA message to the entire network, and only the nodes determined as the publisher relay node transmit the multi-hop CA message including the content information of the neighboring neighbor node to the entire network By broadcasting, the broadcast overhead can be reduced. Therefore, the network can prevent a problem due to broadcast storming or the like, and the performance can also be improved.

Fig. 1H is a conceptual diagram for explaining flooding of an inter-message transmitted by the node 3. Fig. 1H, a node 3 is a content consumer, and a node 9 is a content provider that provides content requested by the node 3. As shown in FIG. 1G, a multi-hop CA A message is broadcasted by the node 5, and the node 3 receives the multi-hop CA message.

Referring to FIG. 1 H, the node 3 determines the range of the inter-message message hop based on the multi-hop CA message broadcast by the node 5 by estimating the distance to the content provider node 9. Specifically, the node 3 confirms that the provider of the content requested by the node 3 is the node 9 based on the one-hop neighbor node content information list (i.e., the content information of the node 9) of the node 5 included in the multi-hop CA message . The node 3 estimates the distance to the node 9 on the basis of the hop count information (HOP Count) included in the multi-hop CA message, and calculates the hop range (four hops) of its own intra- Setting. For example, the node 3 may change the estimated hop count information (Expected HOP) to correspond to the estimated distance in its own intra message.

Node 3 then broadcasts an inter-message with a four-hop flooding hop range. Accordingly, the above-mentioned interleaved message broadcasted by the node 3 is not flooded to more than four hops. The inter-message message is transmitted to the content provider node 9 via the relay nodes 4, 5, 8, and 10 as described with reference to FIGS. 1A to 1E.

Similarly, even when the node 9 receiving the interlace message transmits a data message, the range of the flooding hops may be limited based on the hop range of the interlace message. In this case, the node 9 may change the estimated hop count information (Expected HOP) to correspond to the hop range of the inter- est message in its own data message.

In this way, when any one of the nodes 0 to 10 broadcasts an intra-message for requesting the contents, the flow of the flooding hop based on the multi-hop CA message transmitted through the publisher relay nodes 4, 5, Limit the range. Through this, unrestricted propagation of the interrest message can be prevented, and the broadcast overhead of the network can be reduced.

FIG. 2 is a flowchart illustrating a method of communicating between nodes in a content-based networking environment according to an embodiment of the present invention. FIG. 3 is a flowchart illustrating a process of selecting a relay node in FIG. 2 according to an embodiment of the present invention. FIG. 4 is a flow chart for explaining a step of selecting a publisher relay node in FIG. 2 according to an embodiment of the present invention. In the description of Figs. 2 to 4, for the sake of convenience of description, the portions overlapping with those in Figs. 1A to 1H will be briefly described.

First, a plurality of nodes implementing a content-centric networking environment generate topology information on neighboring node information within two hops from the one itself, based on the CA message received from the one-hop neighboring node (S100). Here, the flooding range of the CA message is limited to one hop.

Then, each of the plurality of nodes selects at least one relay node among its one-hop neighbor nodes based on its topology information (S200).

Referring to FIG. 3, the relay node selection process will be described in detail. The plurality of nodes each calculate MPRcost of its one-hop neighboring node (S210), and determine a node having the largest MPRcost among its one- And selects the relay node (S220). Then, each of the plurality of nodes removes information about a two-hop neighbor node connected through the selected relay node in its topology information (S230). Each of the plurality of nodes determines whether there is information about a two-hop neighboring node in its topology information, and if it is determined in step S210 or S230 that the two- (S240).

Each of the plurality of nodes broadcasts a CA message reflecting a relay node selection result to its own one-hop neighbor node (S300). Accordingly, each of the plurality of nodes can confirm whether it is a relay node or not. Here, the flooding range of the CA message reflecting the relay node selection result is limited to one hop.

The nodes selected as the relay nodes among the plurality of nodes respectively determine whether they are the publisher relay nodes (S400).

Referring to FIG. 4, the publisher relay node determination process will be described in detail. In operation S410, the nodes selected as the relay node determine whether there is a node selected as a relay node among the one-hop neighbor nodes of the relay node. If there is a node selected as a relay node among its own 1-hop neighboring nodes, the nodes selected as the relay node are respectively assigned to one hop neighbor of the node selected as the relay node among the one- It is determined whether the number of nodes is equal to or greater than the number of nodes (S420). Each of the nodes selected as the relay node determines itself as a publisher relay node if the number of its one-hop neighboring node is equal to or greater than the number of one-hop neighboring nodes of the node selected as the relay node among its one-hop neighboring nodes ). Each of the nodes selected as the relay node, if the number of its own 1-hop neighboring node is smaller than the number of one-hop neighboring node of the node selected as the relay node among its own 1-hop neighboring node, The node selection process is terminated.

If there is no node selected as a relay node among its own 1-hop neighbor nodes, each of the nodes selected as a relay node determines itself as a publisher relay node (S430) and ends the publisher relay node selection process.

Among the nodes selected as relay nodes, the nodes determined as the publisher relay node each generate a multi-hop CA message and broadcast the multi-hop CA message to all the nodes of the network through the adjacent relay node (S500).

As described above, according to the present invention, some nodes among the nodes in a network, for example, a MANET, are selected as relay nodes, and an interpreter message and a data message are transmitted, and a publisher relay node is selected from among the relay nodes, To generate and broadcast multi-hop CA messages flooded across the network. Thus, it is possible to prevent channel congestion and collision due to the broadcast characteristic of the MANMET, and reduce the broadcast overhead.

FIG. 5 is a functional block diagram of a node 100 implementing a content-based networking environment according to an embodiment of the present invention. In the description of FIG. 5, for the sake of convenience of description, the portions overlapping with those in FIGS. 1A to 4 will be briefly described.

5, the node 100 includes a topology information storage unit 110, a forwarding information base 120, a relay node selecting unit 130, a CA message generating unit 140, a publisher relay node determining unit 150, A content store 160, and a pendinginterest table 170. [ Although not shown, the node 100 may have an incoming face receiving a CA message from another node and an outgoing face transmitting a CA message to another node. Here, the face may be represented by an interface.

The topology information storage unit 110 may store topology information (top) for neighboring neighboring nodes within two hops from the topology information storage unit 110. FIG. The topology information (top) may include one hop neighbor node information of the node 100, for example, content information of one hop neighbor node, identification information, cache hit rate information, and the like. The topology information may include two-hop neighboring node information connected through the one-hop neighboring node, for example, a content information list of two-hop neighboring nodes, an identification information list, and the like.

The topology information storage unit 110 may generate and store topology information (top) based on a CA message (rCA) received from another node. In some embodiments, the topology information storage 110 includes a filter unit (not shown) for filtering some information in the CA message (rCA) received from the other node and a memory unit (not shown) for storing the filtered topology information (Not shown).

The topology information storage unit 110 may transmit the CA message (rCA) received from the other node to the forwarding information base 120.

The forwarding information base 120 may store at least some information and face information included in the CA message (rCA) received from the other node, and based on this, the node 100 may forward the CA message, etc. to another node .

The relay node selection unit 130 selects a node having the largest MPRcost among the one-hop neighboring nodes of the node 100 as at least one relay node based on the topology information (top) stored in the topology information storage unit 110 . Although not shown, the relay node selection unit 130 includes an MPRcost calculation unit for calculating the MPRcost of the one-hop neighboring node based on the topology information (top) of the node 100, the MPRcost calculation unit for calculating the MPRcost And a topology information storage unit 110 to determine whether the relay node should be continuously selected by checking the information of the two-hop neighboring node of the node 100, And a control unit for generating a signal rem for controlling the change of the neighbor node information.

CA message generation unit 140 may generate a CA message (tCA) for informing another node of the information of node 100. [ The CA message generating unit 140 may receive the content information CI of the node and the topology information top from the content store 160 to generate a CA message tCA. The CA message tCA includes content information, identification information, cache hit rate information, node type information, message type information, and the like of the node 100, a content information list of one-hop neighbor nodes of the node 100, An information list, and the like.

The CA message generating unit 140 receives the relay node selection result information rres from the relay node selecting unit 130 and outputs the relay node selection result information rres to the one- The CA message (tCA) in which the type information of the node selected as the relay node in the node type information list is changed can be generated.

The CA message generating unit 140 receives the publisher relay node determination result information prres from the publisher relay node determining unit 150 and generates the message type of the node 100 based on the publisher relay node determination result information prres Information (CA) message (tCA) can be generated.

The CA message generating unit 140 may arbitrarily generate the CA message tCA as in the case of receiving the relay node selection result information rres or the publisher relay node determination result information prres, And may generate a CA message (tCA) periodically.

The publisher relay node determining unit 150 can determine whether the node 100 is a publisher relay node when the other node receives the CA message (rCA) reflecting the result of selecting the node 100 as a relay node.

When the node 100 is selected as a relay node, the publisher relay node determining unit 150 determines the number of one-hop neighbor nodes of the node 100 and the number of one-hop neighbor nodes of the node 100 based on the topology information (top) It is possible to determine the node 100 as a publisher relay node by comparing the number of one-hop neighboring nodes of other relay nodes.

The publisher relay node determining unit 150 determines whether or not the CA message (rCA) including the information of the node 100 is received from another node for a predetermined period, if the node 100 is selected as a relay node but is not determined as a publisher relay node. The node 100 can be determined as a publisher relay node.

The publisher relay node determination unit 150 may transmit the publisher relay node determination result information prres to the CA message generation unit 140. [

The content store 160 may store the data content and the content list. The contents store 160 may promptly respond to an incoming message for the stored content name.

The pending interlace table 170 transmits the inter-message message to a node capable of transmitting contents in response to the received inter-message message, and determines at which pace (not shown) the inter-message message is input and outputted Records can be managed. Thus, the pendinginterest table 170 allows a data message to be delivered along a reverse path that the inter- est passes through.

Thus, even when the node 100 implements the content-oriented networking environment in the MANET, the node 100 can prevent channel congestion and collision, reduce the broadcast overhead, enable efficient communication, and improve the performance of the MANET.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, This is possible.

100: node 110: topology information storage unit
120: forwarding information base 130: relay node selection unit
140: CA message generating unit 150: Publisher relay node determining unit
160: content store 170: pendinginterest table

Claims (18)

Selecting at least one relay node based on topology information for neighboring neighboring nodes within two hops from the plurality of nodes, respectively;
Each of the selected relay nodes determining whether it is a publisher relay node; And
Generating a multi-hop content announcement message including content information of its one-hop neighbor node, each of the determined publisher relay nodes generating a multi-hop content announce message through the selected relay nodes, Broadcasting the multi-hop content announcement message to the mobile terminal;
A method for communicating between nodes in a content-centric networking environment. 2. The method of claim 1, further comprising: prior to selecting the relay node,
Further comprising: generating the topology information based on a content announce message received from the at least one one-hop neighboring node,
Wherein the topology information includes the one-hop neighboring node information and the two-hop neighboring node information connected through the one-hop neighboring node in the content-centric networking environment. 3. The method of claim 2, wherein the content announcement message comprises:
Information about the one-hop neighbor node, identification information, cache hit rate information, node type information, hop count information, and message type information,
A content information list, an identification information list, and a node type information list for a two-hop neighboring node connected through the one-hop neighboring node,
Wherein a flooding hop range is limited to one hop. 2. The method of claim 1, wherein selecting the relay node comprises:
(a) the plurality of nodes each calculating an MPRcost of its one-hop neighboring node;
(b) selecting, as the relay node, the node having the highest MPRcost among the one-hop neighboring nodes of the plurality of nodes, respectively;
(c) removing information about the two-hop neighboring node, the plurality of nodes each connected through the selected relay node among the two-hop neighboring node information in the topology information; And
(d) repeating the steps (a) to (c) until each of the plurality of nodes is completely removed from the topology information of the own two-hop neighbor node information;
Wherein the content-based networking environment includes a plurality of content-centric networking environments. 5. The method of claim 4, wherein the MPRcost is computed according to Equation (1).
Equation 1

2hRatio (i) represents the number of two-hop neighbor nodes of the arbitrary node and one hop of the i-th one-hop neighbor node, i represents the i-th one-hop neighbor node of the arbitrary node among the plurality of nodes, (I) denotes a ratio between the total number of content requests and the content reply rate of the i-th one-hop neighbor node,? Denotes a weight coefficient, and 0??? 1 2. The method of claim 1, further comprising, between the step of selecting the relay node and the step of determining whether the node is the publisher relay node,
Broadcasting the content announcement message reflecting the selection result of the relay node to the other nodes, respectively;
Further comprising the steps of: receiving a message from the content-centric networking environment; 2. The method of claim 1, wherein determining whether the node is a publisher relay node comprises:
Determining whether each of the selected relay nodes has another node selected as a relay node among its one-hop neighboring nodes;
When there is another node selected as the relay node, when each of the selected relay nodes is equal to or greater than the number of one-hop neighboring node of another node selected as the relay node, Determining as a node; And
If there is no other node selected as the relay node, determining each of the selected relay nodes as a publisher relay node;
Wherein the content-based networking environment includes a plurality of content-centric networking environments. The method of claim 1, further comprising: after the step of broadcasting the multi-hop content announcement message,
When at least one relay node not determined as the publisher relay node among the selected relay nodes fails to receive a multi-hop content announcement message from another publisher relay node for a predetermined time, And broadcasts the multi-hop content announcement message to the plurality of nodes via the selected relay nodes. 2. The method of claim 1,
Hop content announcement message by collecting its own content information and content information of its own one-hop neighbor node,
Hop content announcement message to the plurality of nodes through the selected relay nodes on behalf of the one-hop neighbor node of the own node, and broadcasts the multi-hop content announcement message to the plurality of nodes on the selected relay nodes, . The method of claim 1, wherein the multi-hop content announcement message comprises:
The content information, the identification information, the cache hit rate information, the node type information, the hop count information, and the message type information for each of the determined publisher nodes,
A content information list, an identification information list, and a node type information list for each one-hop neighbor node of each of the determined publisher relay nodes,
Wherein a flooding hop range is two or more hops. The method of claim 1, further comprising: after the step of broadcasting the multi-hop content announcement message,
When a node receiving the multi-hop content advertisement message among the plurality of nodes transmits an interest message for requesting content,
Wherein the node for transmitting the at least one of the plurality of messages includes at least one node for transmitting the at least one message from the node for transmitting the at least one message, Estimating a hop range from the estimated hop range to a predetermined range, and restricting a flooding hop range of the received message based on the estimated hop range. A node that implements a content-centric networking environment,
A topology information storage unit for storing topology information on neighboring neighboring nodes within two hops from itself;
A relay node selecting unit selecting at least one relay node among the one-hop neighboring nodes based on the topology information; And
A publisher relay node determining unit determining whether the node is a publisher relay node broadcasting a multi-hop content announcement message on behalf of the one-hop neighboring node;
≪ / RTI > 13. The method of claim 12, wherein the topology information comprises:
Hop neighbor node information and two-hop neighbor node information connected through the one-hop neighbor node. 13. The method of claim 12,
Wherein the relay node selection unit calculates the MPRcost of the one-hop neighboring node based on the topology information and selects a node having the highest MPRcost among the one-hop neighboring nodes as the relay node,
Wherein the MPRcost is calculated on the basis of at least one of a ratio between the number of two-hop neighboring nodes of the node itself and the number of one-hop neighboring nodes of the one-hop neighboring node and the cache hit rate of the one- . 13. The method of claim 12,
And a content announcement message generation unit for generating a content announcement message,
The content announcement message includes its own content information, identification information, cache hit rate information, node type information, hop count information, and message type information,
A list of contents information of the one-hop neighboring node, an identification information list, and a node type information list. delete 13. The relay station apparatus according to claim 12,
Hop neighboring node receives a content announcement message reflecting a result of selecting itself as a relay node from the one-hop neighboring node, and when there is another relay node among the one-hop neighboring nodes and the number of one- Hop neighbor node is greater than or equal to the number of neighboring hop nodes, or when there is no other relay node among the one-hop neighbor nodes, the node determines itself as a publisher relay node. 18. The apparatus of claim 17, wherein the publisher relay node determiner comprises:
When a multi-hop content announcement message is not received from another node for a predetermined period of time, a content announcement message reflecting a result of selecting itself as a relay node from the one-hop neighboring node is received, Node as a node.

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