KR20090099179A - Multicasting transmission method in mobile ad-hoc network - Google Patents

Abstract

A multicasting transmission method in a mobile ad-hoc network is provided to cluster along with directions of multicast group member nodes and packet-transmit respective clustering groups to one destination, thereby drastically reducing the number of transmission packets. A server node receives a multicast group joining message from a client node configuring a network(S10). The server node clusters multicast group member nodes transmitting the message along with a direction to form an upper layer clustering group(S20). The server node transmits a packet to an upper layer cluster header as a destination(S30). The upper layer cluster header is the nearest node among the multicast group member nodes included in each upper layer clustering group.

Description

How to send multicasting in mobile ad hoc networks {MULTICASTING TRANSMISSION METHOD IN MOBILE AD―HOC NETWORK}

The present invention relates to a multicasting transmission method in a mobile ad hoc network, and in particular, when transmitting a packet from a server node (transmission node) to a multicast group member node (receiving node), clustering the multicast group member nodes in a direction. After forming a plurality of clustering groups, the server node transmits the packet to each of the clustering groups as a destination, thereby reducing the number of transport packets in a multicasting transmission method in a mobile ad hoc network It is about.

Mannet (Mobile Ad-hoc Network) is a network of wireless devices gathered by themselves. Because it can be configured without a base network, it is often used in places where it is difficult to form a base network in advance, such as a disaster area. In this environment, one-to-many communication, or multicasting, occurs a lot. For example, geographic information for a disaster area should be sent to all users in that area. Accordingly, many researches on multicast have been conducted in Mannet.

When a multicast message is delivered to a multicast group, a tree is created when the node receiving the packet is viewed as a dot and the path through which the packet is transmitted is called a multicast tree. Many multicast studies have studied how to build an efficient multicast tree.

How to build a multicast tree is divided into two classes. The first method is to make a structure (tree, mesh) for multicast in advance, and to transmit multicast packets along the structure. Therefore, this method is not suitable for dynamic mannet environments. To compensate for this, a method of dynamically constructing a tree while transmitting a packet has been proposed. This method can also be applied to environments in which nodes move dynamically.

Tree generation techniques for multicasting in Mannet have been focused on minimizing packet transmission time, which causes excessive packet transmission and inefficient cost.

It is very important to reduce the number of packets in the mannet. Since Mannet is a multihop communication, a copy of a packet occurs every time a packet is sent one hop. Therefore, the number of packets increases in proportion to the number of traffic and the distance. Since the resources of the network are limited, one traffic occupies the resources of that area.

Therefore, a large number of packets in an area not only prevents efficient use of resources, but also causes packet loss by causing problems such as hidden terminal problems.

The present invention was devised to solve the above problems of the prior art, and when transmitting a packet from a server node (transmission node) to a multicast group member node (receiving node), the multicast group member nodes are oriented according to directions. After clustering to form a plurality of clustering groups, the server node transmits the packet to each clustering group as a destination, thereby multicasting transmission method in a mobile ad hoc network that can significantly reduce the number of transport packets To provide that purpose.

The constituent means of the multicasting transmission method in the mobile ad hoc network of the present invention proposed to solve the above problems is, in the multicasting transmission method in the mobile ad hoc network, the server node from the client nodes constituting the network Receiving a multicast group join message, wherein the server node clusters the multicast group member nodes that have transmitted the multicast group join message according to a direction to form upper layer clustering groups, and wherein the server node comprises A packet including addresses of the multicast group member nodes included in each of the higher layer clustering groups is forwarded to the upper layer cluster header, which is the closest node among the multicast group member nodes included in the layer clustering group. Characterized in that it comprises a step of sending.

Here, the multicast group join message may include current location information of the client node.

In the forming of the higher layer clustering groups, the server node determines a closest node among the multicast group member nodes as an upper layer cluster header, and then connects the server node to the upper layer cluster header. Forming an initial clustering group by clustering multicast group member nodes positioned outside the line segment perpendicular to the node, wherein the server node checks whether all of the multicast group member nodes are clustered, and thus is not clustered. If it is determined that the member nodes remain, the server node is defined as the higher layer cluster header of the closest node among the remaining multicast group member nodes until all remaining multicast group member nodes are clustered. Wow It characterized in that made in comprising the step of forming additional cluster group to cluster multicast group member node, which is located outside of a line segment perpendicular to a line segment connecting the upper layer based cluster header.

Further, in the process of forming the additional clustering groups, among the multicast group member nodes positioned outside the line segment perpendicular to the line segment connecting the server node and the upper layer cluster header, the first clustering group or the previous additional clustering group may be used. When there are overlapping multicast group member nodes, the overlapping multicast group member nodes are assigned to a clustering group that includes a higher layer cluster header closest to the multicast group member nodes.

In addition, when a client node that does not transmit the multicast group join message is received by the server node, the client node receiving the packet transmits the packet to an upper layer cluster header which is a destination of the packet. Characterized in that.

In addition, when the packet transmitted from the server node is transmitted directly or through a multicast group member node included in the upper layer clustering group, the upper layer cluster header becomes the server node. After clustering the multicast group member nodes included in the upper layer clustering group again according to a direction to form lower layer clustering groups, the upper layer cluster header serving as the server node is selected among the multicast group member nodes clustered again. And an additional transmission step of transmitting a packet including the addresses of the multicast group member nodes included in each of the lower layer clustering groups to the lower layer cluster header, which is the nearest node.

Further, the further transmission step is characterized in that it proceeds until the packet is transmitted to all multicast group member nodes.

According to the multicasting transmission method in the mobile ad hoc network of the present invention having the above problems and solving means, when transmitting a packet from a server node (transmission node) to a multicast group member node (receiving node), the multicast group After clustering member nodes according to a direction to form a plurality of clustering groups, the server node transmits the packet with each clustering group as a destination, so that the number of transport packets can be significantly reduced. have.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the multicasting transmission method in the mobile ad hoc network of the present invention having the above problems, solving means and effects.

1 is a flowchart illustrating a multicasting transmission method in a mobile ad-hoc network according to the present invention. Referring to Figure 1 describes a multicasting transmission method in a mobile ad hoc network according to the present invention.

First, among the client nodes (mobile nodes) constituting the mobile ad hoc network, client nodes wishing to receive multicast transmit a multicast group join message to the server node (s10). When the server node receives the multicast group join message from the client nodes forming the mobile ad hoc network, the server node determines the client nodes sending the multicast group join message as the multicast group member nodes. do.

The server node refers to a transmitting node transmitting a packet, and the client node refers to a receiving node receiving the packet. Therefore, a specific mobile node may be a client node (receiving node) when receiving a packet from another mobile node, and may be a server node (transmitting node) when transmitting a packet to another mobile node. Meanwhile, the multicast group member nodes are nodes which transmit a multicast group join message for multicast reception among mobile nodes constituting the mobile ad hoc network.

The multicast group join message sent by the client nodes that want to receive the multicast includes current location information of each client node. The location information is used to determine the addresses of the multicast group member nodes that have sent the multicast group join message.

When the server node (transport node transmitting a packet) receives the multicast group join message, clustering is performed on the multicast group member nodes that have transmitted the multicast group join message. It forms (s20).

The clustering groups are groups in which the multicast group member nodes are clustered along direction. That is, the clustering is not distance-based clustering as shown in FIG. 2A, but is direction-based clustering as shown in FIG. 2B.

In the distance-based clustering illustrated in FIG. 2A, when a transmitting node (server node) transmits a packet to clustering groups C1, C2, and C3, packets destined for clustering groups C2 and C3 overlap with each other. That is, the packet transmitted to the clustering group C3 passes through the clustering group C2. Therefore, this distance-based clustering does not consider the direction and thus does not effectively reduce the transport packet.

On the other hand, since direction-based clustering applied to the present invention forms a clustering group according to a specific direction, as shown in FIG. 2B, packets going in a similar direction when packets are transmitted one hop can be combined to transmit transport packets. Can be reduced.

However, according to the clustering shown in FIG. 2B, since the number of multicast group member nodes included in one clustering group is large, the effect of reducing a transport packet is small. Therefore, a hierarchical clustering structure in which clustering is repeatedly performed in each clustering group will also be described later.

As illustrated in FIG. 2B, when clustering the multicast group member nodes in a direction, a plurality of clustering groups are formed. In this case, since the clustering groups are formed first, the clustering groups are referred to as higher layer clustering groups. As a result, clustering groups generated within each upper layer clustering group are referred to as lower layer clustering groups. This will be described later.

The forming of the higher layer clustering groups will be described in detail with reference to FIG. 3. Here, the server node is a node that transmits a packet, the multicast group member node is a node that transmits a multicast group join message to the server node in order to receive multicast reception, and the mobile node is a multicast group join message to the server node. It is a node that has not transmitted, and the cluster header is a node located closest to the server node in each clustering group.

First, the server node designates the closest node among the multicast group member nodes as the upper layer cluster header H1. Then, clustering multicast group member nodes located outside the line segment perpendicular to the line segment connecting the server node and the upper layer cluster header forms an initial clustering group (see FIG. 3A).

In this case, the multicast group member nodes positioned outside the line segment perpendicular to the line segment connecting the server node and the upper layer cluster header mean nodes positioned opposite to the server node based on the vertical line segment. It is also preferable to include nodes in which the vertical line segments pass by the clustering group.

After the server node has created the first clustering group as described above, check whether there are any multicast group member nodes that are not clustered. That is, the server node checks whether all the multicast group member nodes are clustered.

As shown in (a) of FIG. 3, when the server node determines that the multicast group member nodes that are not clustered remain, additional clustering is performed until all remaining multicast group member nodes are clustered. To form additional clustering groups.

That is, as shown in (b) of FIG. 3, the server node designates a node located closest among the remaining multicast group member nodes as the upper layer cluster header H2.

Thereafter, additional clustering groups are formed by additionally clustering multicast group member nodes positioned outside the line segment perpendicular to the line segment connecting the server node and the upper layer cluster header (see FIG. 3B).

Here, the multicast group member nodes positioned outside the line segment perpendicular to the line segment connecting the server node and the upper layer cluster header (H2) refer to nodes positioned opposite to the server node based on the vertical line segment. . It is also preferable to include nodes in which the vertical line segments pass by the clustering group.

In the process of forming additional clustering groups as described above, the multicast group member nodes included in the initial clustering group may also be additional clustering targets. The multicast group member nodes which are duplicated and thus clustered are assigned to the clustering group including the upper layer cluster header closest to the multicast group member nodes. That is, the duplicated multicast group member nodes to be clustered are assigned to a clustering group including the H1 upper layer cluster header when H1 is closer to H1 among the higher layer cluster headers H1 and H2. Closer to, the H2 higher layer cluster header is assigned to a cluster group including the header group.

In summary, in the process of forming the additional clustering groups, the first clustering group or the previous additional clustering group among the multicast group member nodes positioned outside the line segment perpendicular to the line segment connecting the server node and the upper layer cluster header. If there are multicast group member nodes that overlap with the group, the duplicated multicast group member nodes are assigned to a clustering group that includes the upper layer cluster header closest to the group.

If the server node is determined to be non-clustered multicaster group member nodes even after the additional clustering group is formed as described above, the additional clustering group formation process as described above is repeated. 3 (b) shows that some non-clustered multicast group member nodes remain.

Accordingly, even after the server node creates the additional clustering group as described above, as shown in FIG. 3C, the server node selects the node located closest to the remaining multicast group member nodes. This is determined by the higher layer cluster header H3.

Thereafter, additional clustering groups are formed by additionally clustering multicast group member nodes located outside the line segment perpendicular to the line segment connecting the server node and the upper layer cluster header H3 (see (c) of FIG. 3). ).

Here, the multicast group member nodes positioned outside the line segment perpendicular to the line segment connecting the server node and the higher layer cluster header H3 mean nodes positioned opposite to the server node based on the vertical line segment. . It is preferable to include the nodes passing the vertical line to the clustering group.

In the process of forming the second additional clustering groups as described above, included in the first clustering group (clustering group formed in (a) of FIG. 3) and the first additional clustering group (clustering group formed in (b) of FIG. 3) Multicast group member nodes may also be subject to a second additional clustering.

When there are duplicated and multicast group member nodes to be clustered as described above, the server node includes the previous clustering group (first clustering group and first clustering group) at the duplicated and multicast group member nodes. The distance between the upper layer cluster headers H1 and H2 included in the upper layer cluster header H3 included in the second additional clustering group is calculated, and the overlapped multicast group member nodes Assign to a clustering group that contains a nearby upper layer cluster header.

That is, in the process of forming the additional clustering groups, the first clustering group or the previous additional clustering group among the multicast group member nodes positioned outside the line segment perpendicular to the line segment connecting the server node and the upper layer cluster header. If there are duplicate multicast group member nodes, the duplicated multicast group member nodes are assigned to a clustering group that contains the upper layer cluster header closest to it.

As described above, all multicast group member nodes are clustered through three clustering processes (first clustering group formation and two additional clustering group formation processes).

When all higher layer clustering groups are formed as described above, the server node (transport node) transmits a packet to each of the higher layer clustering groups (S30). However, in the present invention, when the server node (transport node) transmits a packet to the higher layer clustering groups, the packet is transmitted using one higher layer cluster header included in each higher layer clustering group as a destination. The upper layer cluster header corresponds to a node located closest to the server node (transport node) among the multicast group member nodes included in each of the upper layer cluster groups.

Specifically, the server node (transport node) is the packet among the multicast group member nodes included in each of the higher layer clustering groups, the upper layer cluster header being a node located closest to itself (the server node). Send it.

The packet transmitted from the server node (transport node) to the upper layer cluster header which is the destination of the packet includes the addresses of the multicast group member nodes included in each of the upper layer clustering groups. Addresses of the multicast group member nodes are determined using current location information of each node included in the multicast group join message.

A process of transmitting a packet transmitted from a server node (transmission node) to all multicast group member nodes as described above will be described in detail with reference to FIG. 4.

First, as shown in FIG. 4A, the server node performs clustering on all multicast group member nodes in the manner described above. As a result, three higher layer clustering groups C1, C2, and C3 are formed.

As such, after all upper layer clustering groups are formed, the server node may include each higher layer cluster header included in each higher layer clustering group (among the multicast group member nodes included in each higher layer clustering group, The packet is transmitted to the destination (node closest to the node). The packet transmitted in each upper layer cluster header includes addresses of all multicast group member nodes in each upper layer clustering group including the upper layer cluster header.

As described above, when a packet is transmitted from a server node to each upper layer cluster header, the packet is transmitted to the upper layer cluster header which is a destination. In this process, the packet may be directly transmitted to the upper layer cluster header, but may be transmitted through a client node (mobile node) rather than a multicast group member node. Here, the client node (mobile node) refers to a mobile node that has not sent a multicast group join message to the server node.

As described above, when a client node (mobile node) not transmitting the multicast group join message is received from the server node, the client node (mobile node) receiving the packet receives the packet. Transmit to the upper layer cluster header which is the destination of the packet.

Specifically, the client node (mobile node) receiving the packet analyzes the packet and checks whether the packet includes its address. Since the client node (mobile node) is not a multicast group member node, the packet will not contain the address of the client node (mobile node). Therefore, the client node (mobile node) is to send the packet to the destination upper layer cluster header. Referring to FIG. 4A, it is shown that a packet transmitted to C3 is transmitted through a client node (mobile node) among upper layer clustering groups.

Meanwhile, the packet transmitted from the server node may not be directly transmitted to the upper layer cluster header, but may be transmitted through a multicast group member node included in the upper layer clustering group including the upper layer cluster header. That is, the packet transmitted from the server node is transmitted directly or through a multicast group member node in which the upper layer cluster header is included in the upper layer clustering group.

As described above, when a packet is transmitted from a server node to each higher layer cluster header H1, H2, and H3 included in each higher layer clustering group C1, C2, and C3, the upper layer cluster headers H1, H2, H3) becomes a server node (transport node) to perform the above-described clustering, thereby forming a plurality of lower layer clustering groups. That is, when the upper layer cluster headers H1, H2, and H3 receive the packet transmitted from the server node, the upper layer cluster headers H1, H2, and H3 exclude the own address included in the packet. The remaining destinations (multicast group member nodes) are clustered based on their location.

Specifically, the upper layer cluster headers H1, H2, and H3 become the server nodes (transport nodes) to cluster the multicast group member nodes included in the upper layer clustering group again according to a direction to lower layer. Form clustering groups. In FIG. 4B, lower layer clustering groups of C21, C31, and C32 are formed. The clustering method is the same as the method described above.

As such, after forming the lower layer clustering groups C21, C31, and C32, the upper layer cluster headers H1, H2, and H3 that become the server node (transport node) are clustered again. The packet is further transmitted to the lower layer cluster header, which is the closest node among the nodes. This transmission method is also the same as the method in which the server node shown in FIG. 4 (a) transmits a packet to upper layer cluster headers H1, H2, and H3.

The packet transmitted by the upper layer cluster headers H1, H2, and H3 includes addresses of multicast group member nodes included in each lower layer clustering group. After clustering is performed again in the higher layer clustering group, when the packet is transmitted, the packet may be transmitted to most multicast group member nodes.

However, if clustering is needed again based on the direction in the lower layer clustering group, after performing clustering by the above-described method, the packet is transmitted to the destination. 4C shows that clustering is performed in the lower layer clustering group of C21 to form the lower layer clustering group of C22. In fact, the lower layer clustering group of C22 is a clustering group that is hierarchically lower than the lower layer clustering group of C21.

As above, an additional step of forwarding the packet from the upper layer clustering group to the lower layer clustering group proceeds until the packet is sent to all multicast group member nodes. 4 (c) shows a state in which the packet is transmitted to all multicast group member nodes.

Hereinafter, an experimental example for demonstrating the performance of the present invention.

The experiment used a network simulator ns-2 (described at http://www.isi.edu/nsnam/ns/ .) For the simulation. The simulation environment was set as follows.

The MAC layer is IEEE 802.11 and the routing protocol is GPSR [B. Karp and HT Kung, "Greedy perimeter stateless routing for wireless networks", in ACM / IEEE MOBICOM , August 2000, pp. 243-254.] Was used. The radio range and grid size of the nodes used in the simulation is 250 meters.

The 200 nodes were randomly located in a network of square and 2500 square meters, among which server and member nodes were randomly selected for each scenario. Multicast packets have a data portion of 64 bytes.

All simulations averaged ten times in different scenarios. The simulation time is 100 seconds and the multicast is started 40 seconds after the start of simulation in order to have enough time to initialize the multicast group.

Here, RSGM [X. Xiang, Z. Zhou, and X. Wang, "Robust and Scalable Geographic Multicast Protocol for Mobile Ad Hoc Networks", in IEEE INFOCOM , 2007.].

Because direction-based clustering is a packet transmission method for efficient multicast, a multicast group management scheme is required. For fair comparison, the group management scheme of RSGM is used as it is and only the multicast transmission portion is compared.

Factors used in the group management scheme of the RSGM are defined as shown in FIG. In addition, multicasting starts from 3 seconds after receiving the first report message so that all the report messages can be multicasted, and the interval of multicasting is set to 10 seconds. In the simulation in this experiment, the following factors of RSGM and direction-based clustering were compared.

1. Packet transmission rate: The ratio of the number of data packets received by group members to the number of data packets transmitted by the server. This represents the reliability of the multicast transmission method.

2. Number of relay nodes: The number of relay nodes is the total number of nodes that forward packets to other nodes so that multicast data packets can be sent to all group members. In a mannet, each time a packet is forwarded, the packet is copied. Since all relay nodes send more than one packet, the number of relay nodes affects the number of packets.

3. Total number of packets: The total number of packets until one multicast data arrives from the server to all members of the multicast group. This represents the efficiency of the multicast transmission method.

4. Number of nodes for clustering operation: Number of nodes performing clustering operation among relay nodes. It represents the computational overhead imposed on the entire network for multicast data to reach the entire multicast group.

5. Average Hops: The average number of hops in the path from the server to each destination. This is the time it takes for the destination to receive multicast packets.

6 shows the packet transmission rate according to the multicast group size. When the multicast group management scheme is performed by RSGM and the transmission of packets by GPSR, the packet transmission rate is almost similar between the two algorithms. This shows that the direction-based clustering algorithm also provides excellent packet transfer rates.

7 shows the number of relay nodes according to the size of a multicast group. In the direction-based clustering algorithm, the number of relay nodes is less than RSGM. It clusters by comparing only the next hop when clustering in RSGM, but the direction-based clustering algorithm reduces the number of relay nodes more efficiently because it clusters by looking at the location of all multicast group members.

In addition, in the direction-based clustering algorithm, even if the size of the multicast group increases, the number of relay nodes does not increase significantly because more group members are clustered.

8 shows that direction based clustering reduces the number of packets as well as the number of relay nodes more effectively than RSGM. As the size of the multicast group increases, the increase rate of the number of packets decreases because the number of nodes clustered into one cluster increases as the size of the multicast group increases. The packet growth rate of the proposed scheme is smaller than that of the conventional RSGM because it clusters the entire network to minimize the number of packets.

9 shows the number of compute nodes according to the multicast group size. RSGM performs clustering operation on all relay nodes. On the other hand, the proposed scheme reduces the computation added to the entire network by selectively computing only some of the relay nodes.

As the size of the multicast group increases, the RSGM constantly increases the number of compute nodes, while the proposed scheme increases rapidly. This increases the number of compute nodes due to the complexity of the cluster hierarchy as the group size grows.

10 shows the average hop number according to the multicast group size. The average hop count is larger than the RSGM of the proposed technique. This is because RSGM delivers packets at the shortest distance by GPSR, but the proposed scheme clusters nodes that are not the shortest distance to further reduce the number of packets.

As described above, the present invention proposes a direction-based clustering method as a method of transmitting a multicast packet more efficiently than the conventional method. In the present invention, members in similar regions are clustered according to the geographic information of the multicast group members.

In packet transmission, one cluster is treated as one node, reducing the number of packets by compressing the packet paths to all nodes in the cluster into one. In addition, not all relay nodes perform clustering operations, but clustering operations only when member nodes serve as relays, thereby reducing the overall network overhead required for transmitting multicast packets.

Simulation results show that the proposed scheme always has fewer packets than RSGM regardless of multicast group size. In addition, the number of nodes operating is much smaller.

1 is a flowchart illustrating a multicasting transmission method in a mobile ad hoc network according to the present invention.

2A and 2B are schematic diagrams for explaining distance-based clustering and direction-based clustering applied to the present invention.

3 is a schematic diagram showing an example of clustering according to the present invention.

4 is a schematic diagram illustrating the stepwise transmission of a multicast packet in accordance with the present invention.

5 is a table showing elements used for multicast group management in an experimental example according to the present invention.

6 is a graph showing packet transmission rate according to multicast group size in an experimental example according to the present invention.

7 is a graph showing the number of relay nodes according to the multicast group size in the experimental example according to the present invention.

8 is a graph showing the number of packets according to the multicast group size in the experimental example according to the present invention.

9 is a graph showing the number of compute nodes according to the multicast group size in the experimental example according to the present invention.

10 is a graph showing the average number of hops according to the multicast group size in the experimental example according to the present invention.

Claims (7)

In the multicasting transmission method in a mobile ad hoc network, Receiving, by the server node, a multicast group join message from client nodes constituting the network; Clustering, according to a direction, the multicast group member nodes that have sent the multicast group join message to the server node to form higher layer clustering groups; The server node includes addresses of the multicast group member nodes included in each higher layer clustering group, using the upper layer cluster header which is a node located closest among the multicast group member nodes included in each higher layer clustering group as a destination. Multicasting transmission method in a mobile ad hoc network comprising the step of transmitting a packet. The method according to claim 1, The multicast group join message includes current location information of the client node. The method of claim 1, wherein forming the higher layer clustering groups comprises: A multicast group member positioned outside the line segment perpendicular to the segment connecting the server node and the upper layer cluster header after the server node designates the closest node among the multicast group member nodes as the upper layer cluster header Clustering the nodes to form an initial clustering group, If the server node checks whether all of the multicast group member nodes are clustered and determines that the non-clustered multicast group member nodes remain, until all remaining multicast group member nodes are clustered, After determining the closest node among the remaining multicast group member nodes as an upper layer cluster header, clustering multicast group member nodes positioned outside the line segment perpendicular to the line connecting the server node and the upper layer cluster header. Multicasting transmission method in a mobile ad hoc network comprising the step of forming additional clustering groups. The method according to claim 3, In the process of forming the additional clustering groups, among the multicast group member nodes positioned outside the line segment perpendicular to the line connecting the server node and the upper layer cluster header, the clustering group overlaps with the first clustering group or the previous additional clustering group. And if there are multicast group member nodes, the duplicated multicast group member nodes are assigned to a clustering group that includes a higher layer cluster header closest to the multicast group member nodes. The method according to claim 1, When a client node that does not transmit the multicast group join message is received by the server node, the client node receiving the packet transmits the packet to a higher layer cluster header which is a destination of the packet. Multicasting transmission method in a mobile ad hoc network characterized by. The method according to claim 1, When the packet transmitted from the server node is transmitted directly through the upper layer cluster header or through a multicast group member node included in the upper layer clustering group, the upper layer cluster header becomes the server node and the upper layer. After clustering the multicast group member nodes included in the clustering group again according to a direction to form lower layer clustering groups, the upper layer cluster header that becomes the server node is the closest among the multicast group member nodes that are clustered again. And transmitting a packet including the addresses of the multicast group member nodes included in each of the lower layer clustering groups as a destination using a lower layer cluster header which is a located node. Multicasting transmission method in De hoc networks. The method according to claim 6, The further transmission step is carried out until the packet is sent to all the multicast group member nodes, multicasting transmission method in a mobile ad hoc network.

Images