KR20060066011A - Method and method for determining operation mode of node in mobile communication system - Google Patents

Abstract

The present invention relates to a mobile communication system in which a mobile node capable of performing a relay function exists. In the method of determining an operation mode of the mobile node, determining a relay function if the power value of the mobile node is greater than or equal to a predetermined threshold power value, and relaying if the power value of the mobile node is less than or equal to a predetermined threshold power value And determining not to perform the function.

Mobile Node, Pilot, Beacon, Relay, Cellular Network, Ad Hoc Network

Description

Method of determining the operation mode of a node in a mobile communication system and a system therefor {METHOD FOR DECIDING OPERATION OF NODE IN A MOBILE COMMUNICATION SYSTEM AND SYSTEM THEREOF}             

1 is a diagram illustrating a network structure when a cellular network and an ad hoc network are interworked.

2 is a diagram illustrating a connection procedure between networks having different hierarchical structures.

3 is a flowchart illustrating a process of determining an operation mode of a mobile node in a mobile communication system according to an embodiment of the present invention.

FIG. 4 is a diagram illustrating an activated or deactivated layer according to the operation mode determination of FIG. 3.

TECHNICAL FIELD The present invention relates to a mobile communication system, and more particularly, to a method and system for determining an operating mode of an ad hoc node.

In general, an ad hoc network means a network composed of two or more devices having wireless communication and networking functions. The ad hoc network has an effect of extending the service radius while increasing the user capacity of the entire network by providing network connectivity to nodes belonging to the network to other nodes.

For example, when a first ad hoc node attempts to transmit a packet to a third ad hoc node beyond its propagation reach, it transmits the packet via a second ad hoc node that is an intermediate node, that is, an intermediate node. Can be. Such an ad hoc node performing a relay function is called a relay node. Typically, ad hoc nodes belonging to the ad hoc network may perform this relay function.

Meanwhile, one of the fields currently being studied in the next generation mobile communication system is a system in which a cellular network and an ad hoc network interwork. The characteristics of existing ad hoc networks do not require a separate infrastructure such as a base station, wire or cable, router or bridge. This would be possible. Therefore, integrating an ad hoc network that does not require the infrastructure to the currently operating cellular network can reduce the cost required for system configuration.

In addition, various types of nodes exist in the cellular network to communicate with each other. The ad hoc network has an advantage that a network can be formed with different kinds of devices. Accordingly, when the cellular network and the ad hoc network are interworked, not only many effects will be generated but also it will not be difficult to implement.

Next, a description will be given of the network structure when the cellular network and the ad hoc network are interworking with reference to FIG. 1.

1 is a diagram illustrating a network structure when a cellular network and an ad hoc network are interworked.

Referring to FIG. 1, first, a network having a cellular structure includes a base station, that is, an access point (hereinafter, referred to as an 'AP') 101. Therefore, the AP 101 is an essential component that must exist even in a network where a cellular network and an ad hoc network are interworked. The AP 101 provides access to the wired network to nodes that are within its cell management radius. In addition, uplink traffic of the nodes to a wired network, and downlink traffic of a wired network is transmitted to the nodes. Generally, the AP 101 is a fixed network component, but may be configured as an AP having mobility according to a network implementation.

In FIG. 1, the AP 101 communicates with a first user terminal (hereinafter referred to as UE) 107 and a node 103 that performs a single hop relay function. Is doing. Here, the node that performs the single hop relay function (hereinafter, referred to as a "single hop relay node") 103 maintains the connectivity with the AP 101 and on the other hand, the cell radius of the AP 101. Communication with the multi-hop relay node 105 located outside and the second UE 111 and the third UE 113 is also performed.

Accordingly, the single hop relay node 103 must have a layer structure of the cellular network and a layer structure of the ad hoc network.

The multi-hop relay node 105 is an ad hoc node connected to any relay node belonging to a cellular network while providing connectivity to nodes of another cellular network or ad hoc network. Therefore, the multi-hop relay node 105 should also have a hierarchical structure of a cellular network and an ad hoc network. Meanwhile, the second UE 111 and the third UE 113 do not perform a relay function. In addition, the first UE 107 also maintains a direct connection with the AP 101 and does not perform a relay function.

As described above, when a network having a cellular structure and an ad hoc network are interworked, it is necessary to determine whether a node operates as a relay node or a terminal that does not perform a relay function to another node. No definition exists.

2 is a diagram illustrating a connection procedure between networks having different hierarchical structures.

FIG. 2 illustrates a connection procedure between the AP 101 <-> single hop relay node 103 <-> multi-hop relay node 105 <-> the second UE 111 or the third UE 113 of FIG. Is showing.

That is, reference numeral 201 denotes a hierarchical structure possessed by the second UE 111 or third UE 113, and reference numeral 203 denotes a hierarchical structure possessed by the multi-hop relay node 105. 205 denotes a hierarchical structure of the single hop relay node 103, and reference numeral 207 denotes a hierarchical structure of the AP 101.

In this case, the operation between the single hop relay node 103 and the multi-hop relay node 105 follows the ad hoc network method. The hierarchical structure according to the ad hoc network method will be denoted as '# 1'. That is, the meaning of the medium access control (MAC) layer # 1 and the physical layer # 1 means a hierarchical structure according to the ad hoc network method.

Meanwhile, the operation between the single hop relay node 103 and the AP 101 is based on the cellular network scheme. In addition, the operation between the multi-hop relay node 105, the second UE 111 and the third UE 113 is also performed according to a cellular network scheme. The hierarchical structure according to the cellular network scheme will be denoted by '# 2'. That is, the meaning of the MAC layer # 2 and the physical layer # 2 means a hierarchical structure according to the cellular network method.

Accordingly, the single hop relay node or the multi-hop relay node that communicates between the cellular network and the ad hoc network has all of the MAC layer # 1, the physical layer # 1, the MAC layer # 2, and the physical layer # 2.

The second UE 111 or the third UE 113 has a layer specification 210 of a cellular network, MAC layer # 2 according to the multi-hop relay node 105 and the cellular network layer specification, and a physical layer. Communication is performed using # 2 (201).

The multi-hop relay node 105 communicates with the second UE 111 or the third UE 113 according to a cellular network layer standard, and the single hop relay node 103 and the ad hoc network layer standard. The relay function may also be performed using the MAC layer # 1 and the physical layer # 1 according to step 203.

The single hop relay node 103 has the same hierarchical standard as the multi-hop relay node 105. Accordingly, the single hop relay node 103 performs a relay function using the MAC layer # 1 and the physical layer # 1 according to the multi-hop relay node 105 and the ad hoc network layer standard, and the AP In step 205, communication with the cellular network layer standard is performed.

The AP 101 has a layer standard of a cellular network and performs communication using the single hop relay node 103 and the MAC layer # 2 and the physical layer # 2 according to the cellular network layer standard (207). .

As described above, in the conventional ad hoc network, all nodes may perform a relay function. However, when the nodes perform a relay function, the nodes relay signals to other nodes and thus consume power other than the power used by the nodes. Therefore, it is preferable that a node capable of sufficiently performing the relay function becomes a relay node. However, no specific operation mode definition exists for this.

In addition, even when an ad hoc network and a cellular network are interworked with the next generation mobile communication system, whether or not an arbitrary node will act as a relay node capable of performing a relay function, and without performing a relay function, There is no clear definition of whether to communicate only.

Accordingly, an object of the present invention is to provide a method for determining an operation mode of a node in a mobile communication system performing a relay function.

Another object of the present invention is to provide a method for providing connectivity between heterogeneous networks in a mobile communication system in which heterogeneous networks interwork.

The first method of the present invention was devised to achieve the above objects; In a mobile communication system having a mobile node capable of performing a relay function, in a method of determining an operation mode of the mobile node, determining to perform a relay function when a power value of the mobile node is greater than or equal to a predetermined threshold power value. And determining not to perform the relay function when the power value of the mobile node is less than or equal to a predetermined threshold power value.

The second method of the present invention was created to achieve the above objects; In a mobile communication system in which a first network and a second network are interworked and each has a hierarchical standard of the first network and the second network, the mobile node performs a relay function. A signal transmission and reception method according to a determination of an operation mode of a node, the method comprising: determining to perform a relay function when a power value of the mobile node is greater than or equal to a predetermined threshold power value, and the mobile node is transmitted from a base station of the first network; Retrieving a reference signal and relaying a signal transmitted and received between a base station of the first network and a mobile node existing in the second network when the reference signal is detected.

The system of the present invention, devised to achieve the above objects; In a mobile communication system in which a first network and a second network are interworked and each has a hierarchical standard of the first network and the second network, the mobile node performs a relay function. In the signal transmission and reception system according to the operation mode determination of the node, if the reference signal transmitted from the base station of the first network having a predetermined threshold power value or more, and is present in the base station and the second network of the first network; A first mobile node for relaying a signal transmitted and received between mobile nodes and another mobile node having a threshold power value or more and not detecting a reference signal transmitted from a base station of the first network, and performing a relay function. In the case of detecting a broadcast advertising signal, zones exist in the first mobile node and the second network. Article characterized in that it comprises a base station of the first network that performs communication according to the second mobile node and the first mobile node and the cellular network layer specification for relaying signals transmitted and received between the mobile node.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, only parts necessary for understanding the operation according to the present invention will be described, it should be noted that the description of other parts will be omitted in the scope that does not distract from the gist of the present invention.

The present invention proposes a method for determining whether an arbitrary node operates as a relay node that performs a relay function or a node that does not perform a relay function in a mobile communication system using a relay function.

In particular, the present invention is most preferably applicable to a mobile communication system in which a cellular network and an ad-hoc network which are being studied as a next generation mobile system are interworked. In other words, when the cellular network and the ad hoc network are interworked, a method for determining an operation mode of a node may be provided, thereby ensuring stable inter-network connectivity and ensuring a wide service area.

Accordingly, in the present invention, a mobile node capable of simultaneously accessing the cellular network and the ad hoc network is targeted. The mobile node has both a cellular network layer specification and an ad hoc network layer specification, and is equipped with a power manage module according to the present invention. The ad hoc network layer specification will be referred to as '# 1' and the cellular network layer specification will be referred to as '# 2'.

3 is a flowchart illustrating a process of determining an operation mode of a mobile node in a mobile communication system according to an embodiment of the present invention.

Referring to FIG. 3, first, in step 301, the mobile node starts to drive by input power and proceeds to step 303. In step 303, the mobile node determines whether the mobile node can perform a stable power source. That is, the power management module provided in the mobile node checks the power source to determine whether the mobile node is operable as a relay mobile node. As a result of the determination, it is determined that the mobile node is operable as a relay mobile node when the mobile node is connected to a DC power source and is continuously supplied with power or when there is power above a predetermined threshold power value.

If it is determined that the mobile node can operate as a relay mobile node, the flow proceeds to step 305. In step 305, the mobile node determines whether there are enough resources to accommodate the wireless connection of other mobile nodes even if it has or can maintain stable power. As a result of the determination, in step 307, the mobile node operates as a relay mobile node, and the physical layer # 1 according to the cellular network layer standard, and medium access control (hereinafter referred to as 'MAC'). By activating layer # 1, a pilot signal or a beacon signal transmitted from an access point (hereinafter referred to as 'AP') is searched for. In step 309, if the pilot signal or the beacon signal is detected as a result of the search. Here, the beacon signal is a kind of reference signal transmitted from the AP and received by the mobile node in a concept similar to a pilot signal. Only if the pilot signal is processed at the physical layer, the only difference is that the beacon signal is processed at the MAC layer.

In step 309, the relay mobile node establishes a direct connection with the AP, and performs a relay function so that the AP transmits and receives a signal to nodes existing outside a cell radius of the AP. That is, in step 309, the relay mobile node operates as a single hop relay mobile node and transmits a pilot signal or a beacon signal transmitted from the AP. In addition, the physical layer # 2 and the MAC layer # 2 according to the ad hoc network layer standard are activated, and an ad hoc advertisement signal is broadcast.

On the other hand, if no pilot signal or beacon signal is detected in step 307, the process proceeds to step 311. In step 311, the relay mobile node activates physical layer # 2 and MAC layer # 2 according to the ad hoc network layer standard, and determines whether an ad hoc advertisement signal is received. As a result of the determination, when detecting the ad hoc advertisement signal, the process proceeds to step 313. In step 313, the relay mobile node may communicate with a corresponding relay mobile node that broadcasts the ad hoc advertisement signal. That is, the relay mobile node operates as a multi hop relay mobile node. The multi-hop relay mobile node transmits a pilot signal or a beacon signal in the same manner as the single hop relay mobile node.

On the other hand, even if the relay mobile node has a condition to perform a relay function, if it does not detect a pilot signal or a beacon signal and does not detect an ad hoc commercial, the process proceeds to step 315 and communication is impossible. Done.

If the mobile node fails to operate as a relay mobile node because it does not satisfy the conditions of step 303 or step 305, the mobile node deactivates the physical layer # 1 and the MAC layer # 1, and performs step 317. Meanwhile, in step 303, when the power value of the mobile node is less than or equal to a predetermined power value, the mobile node does not operate as a relay mobile node. In addition, the mobile node equipped with a battery does not operate as a relay node. In addition, in step 305, the mobile node does not operate as a relay mobile node when there is sufficient power but insufficient resources to accommodate other mobile nodes.

In step 317, the mobile node searches for a pilot signal or a beacon signal. As a result of the discovery, if the pilot signal or the beacon signal is detected, the mobile node proceeds to step 319 and the mobile node performs a network entry procedure with the AP. However, if the mobile node does not detect the pilot signal or the beacon signal in step 317, it proceeds to step 315. In step 315, the mobile node cannot perform communication.

FIG. 4 is a diagram illustrating an activated or deactivated layer according to the operation mode determination of FIG. 3.

Referring to FIG. 4, the shaded portion means an inactivated region, and the non-shaded portion is an activated region.

401 represents an activated or deactivated layer of a relay mobile node determined to perform a relay function. The relay mobile node operates as a single hop relay mobile node or a multi-hop relay mobile node, and performs physical layer # 1 to perform an ad hoc routing protocol for ad hoc traffic transmission and relay functions to other mobile nodes. Activate MAC layer # 1. In addition, the relay mobile node also activates physical layer # 2 and MAC layer # 2 to maintain connectivity with the AP. This activation or deactivation layer decision control is performed by the power management module. Meanwhile, the relay mobile node deactivates a user application layer, a transport layer, and a network layer. Here, when the relay mobile node transmits its traffic to another node or base station, the relay mobile node activates the application layer, transport layer, and network layers. However, it should be noted that the layers that are activated only upon transmission of their traffic are not bound with MAC # 1 and PHY # 1.

On the other hand, 403 represents an activated or deactivated layer of a mobile node that does not need to perform a relay function. The mobile node deactivates the ad hoc routing protocol for ad hoc traffic transmission, physical layer # 1, which is an ad hoc network layer, and MAC layer # 1. However, the mobile node activates physical layer # 2 and MAC layer # 2 to maintain connectivity with the AP. This activation or deactivation layer decision control is performed by the power management module. In addition, the relay mobile node enables user application layer, transport layer and network layers to activate user traffic transmission.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

As described above, the present invention may determine whether to operate as a relay mobile node or a mobile node that does not perform a relay by mounting a power management module in a mobile communication system that performs a relay function. That is, if there is a sufficient power value or sufficient resources to enable the connection of another mobile node, it operates as a relay mobile node, otherwise it operates as a general mobile node. Accordingly, there is an advantage that can efficiently control the power of the relay mobile node or a general mobile node. In addition, when a cellular network and an ad hoc network interwork, there is an advantage of providing stable connectivity between the heterogeneous networks and ensuring a wide service area by providing a method of determining an operation mode of a mobile node.

Claims (19)

In a mobile communication system in which a mobile node capable of performing a relay function exists, the method of determining an operation mode of the mobile node, Determining to perform a relay function when the power value of the mobile node is greater than or equal to a predetermined threshold power value; And determining not to perform a relay function when the power value of the mobile node is less than or equal to a predetermined threshold power value. The method of claim 1, If the power value of the mobile node is greater than or equal to a predetermined threshold power value, and has a radio resource enough to perform a relay function for a signal of another mobile node, the mobile node is determined to be a mobile node to perform the relay function. Said method. In a mobile communication system in which a first network and a second network are interworked and each has a hierarchical standard of the first network and the second network, the mobile node performs a relay function. In the signal transmission and reception method according to the operation mode of the node, Determining to perform a relay function when the power value of the mobile node is greater than or equal to a predetermined threshold power value; The mobile node searching for a reference signal transmitted from a base station of the first network; Detecting the reference signal, relaying a signal transmitted and received between a base station of the first network and a mobile node existing in the second network. The method of claim 3, When the mobile node which does not detect the reference signal detects an advertisement signal broadcast by another mobile node performing a relay function, the mobile node exists in the first network and exists in the second network and performs the relay function. And repeating a signal transmitted and received between mobile nodes. The method of claim 3, If the power value of the mobile node is greater than or equal to a predetermined threshold power value, and has a radio resource enough to perform a relay function for a signal of another mobile node, the mobile node is determined to be a mobile node to perform the relay function. Said method. The method of claim 3, Determining not to perform a relay function when the power value of the mobile node is less than or equal to a predetermined threshold power value; The mobile node searching for a reference signal transmitted from a base station of the first network; And detecting and transmitting a signal with a base station of the first network. The method of claim 6, The mobile node determined not to perform the relaying function searches for a reference signal transmitted from a base station of the first network by activating a physical layer and a media access control layer of the first network among the layer specifications of the mobile node. Said method. The method of claim 7, wherein And when the mobile node detects a reference signal, deactivates a physical layer and a medium access control layer of the second network. The method of claim 3, The mobile node determined to perform the relay function searches for a reference signal transmitted from a base station of the first network by activating a physical layer and a medium access control layer of the first network among the layer specifications of the mobile node. The method. The method of claim 9, And when the mobile node detects a reference signal, activates a physical layer and a medium access control layer of the second network to broadcast an advertisement signal. The method of claim 3, Wherein the first network is a cellular network and the second network is an ad hoc network. In a mobile communication system in which a first network and a second network are interworked and each has a hierarchical standard of the first network and the second network, the mobile node performs a relay function. In the signal transmission and reception system according to the operation mode of the node, A first movement relaying a signal transmitted and received between a base station of the first network and a mobile node existing in the second network when detecting a reference signal transmitted from a base station of the first network with a predetermined threshold power value or more; Nodes, When the mobile station has a predetermined threshold power value or more, does not detect a reference signal transmitted from a base station of the first network, and detects an advertisement signal broadcast by another mobile node performing a relay function, the first mobile node and the mobile station. A second mobile node for relaying signals transmitted and received between mobile nodes existing in the second network; And a base station of a first network communicating with the first mobile node according to a cellular network layer standard. The method of claim 12, And a base station of the first network transmits and receives a signal to and from a third mobile node that does not perform a relay function as having a predetermined threshold power value or less. The method of claim 13, And the third mobile node retrieves a reference signal transmitted from a base station of the first network by activating a physical layer and a media access control layer of the first network among the layer specifications of the third mobile node. The method of claim 14, And when the third mobile node detects a reference signal, deactivates a physical layer and a medium access control layer of the second network. The method of claim 12, And the first mobile node or the second mobile node may perform the relay function when the first mobile node or the second mobile node has radio resources sufficient to perform a relay function on a signal of another mobile node. The method of claim 12, The first mobile node or the second mobile node retrieves the reference signal transmitted from the base station of the first network by activating the physical layer and the media access control layer of the first network of the layer standard it has. The system described above. The method of claim 17, And when the first mobile node reference signal is detected, activates a physical layer and a medium access control layer of the second network to broadcast an advertisement signal. The method of claim 12, Wherein the first network is a cellular network and the second network is an ad hoc network.

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