Mobile communication terminal for providing ad-hoc network service and method for managing ad-hoc network using the same

A method for managing an ad-hoc network using a mobile communication terminal is disclosed. The method includes creating an address table that stores ad-hoc network addresses of the mobile communication terminals and a routing table that stores routing information of the terminals, allocating an address to a first mobile communication terminal and storing the result in the address table, receiving topology change information of the ad-hoc network from the first terminal, updating the routing table and then transmitting it to the first terminal and other ad-hoc network participating terminals. Since the ad-hoc network is managed using the mobile communication network system, the mobile communication network and the ad-hoc network are all effectively managed.

PRIORITY

This application claims priority to an application entitled “MOBILE COMMUNICATION TERMINAL FOR PROVIDING AD-HOC NETWORK SERVICE AND METHOD FOR MANAGING AD-HOC NETWORK USING THE SAME” filed in the Korean Intellectual Property Office on Jun. 19, 2006 and assigned Serial No. 2006-0054744, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a mobile communication terminal for providing an ad-hoc network service and a method for managing an ad-hoc network using the same. More particularly, this invention relates to a dual mode mobile communication terminal that can support a mobile communication network (e.g., a cellular network) service and an ad-hoc network service, and to a method for managing an ad-hoc network formed among such mobile communication terminals.

2. Description of the Related Art

With the development of mobile communication technology related to mobile communication terminals (e.g., mobile phones, Personal Digital Assistants (PDAs), and laptop computers), such terminals now employ a variety of functions. For example, a mobile phone could only provide wireless voice calling in its early stages of development, but now can support transmission of text and images in addition to voice calling.

Particularly, as technology for loading memory, which can store large multimedia files (e.g., moving images and music video) and data transmission technology are developed, a mobile communication terminal can now transmit/receive such multimedia files to/from other mobile communication terminals.

As such, while a variety of functions are added to mobile communication terminals, a communication method has been proposed by which mobile communication terminals can communicate with each other without passing through a mobile communication network such as a cellular network. Examples of such a communication method are 802.11 WiFi, 802.15 Wireless Personal Area Network (WPAN), Bluetooth®, Ultra Wide Band (UWB), Zigbee®, Infrared (IR) and 802.16 Wireless Metropolitan Area Network (WMAN).

An ad-hoc network refers to a network in which moving nodes (e.g., mobile communication terminals) having wireless interfaces autonomously communicate with each other using the above listed communication methods. That is, in the ad-hoc network, the moving nodes are connected to each other through a plurality of hops and then perform communication. Each moving node functions as an end node (e.g., a host) or an intermediate node (e.g., a router). Therefore, although a node intended to communicate with another node (where they are referred to as ‘ad-hoc network participation node’ or ‘ad-hoc network participants’) is not directly or indirectly connected to another node through a physical wireless link, the ad-hoc network allows the ad-hoc network participants to communicate with each other though other nodes.

In addition, the ad-hoc network allows the ad-hoc network participants to voluntarily set each other and to freely participate or secede to/from the network. However, the ad-hoc network has restrictions due to its energy sources, since it is battery operated. Also, the ad-hoc network causes frequent environment variations (e.g., since the participation nodes are moved) according to wireless network characteristics. Therefore, the ad-hoc network has a frequently varying network topology.

Accordingly, the conventional ad-hoc network has disadvantages in that it does not handle the network management well. In particular, the conventional ad-hoc network makes it difficult to allocate addresses to nodes and manage them.

The conventional mobile communication terminal, which is connectable to both the mobile communication network and the ad-hoc network, employs a method in which Internet Protocol version 6 (IPv6) address is statically allocated. However, since the introduction of the IPv6 address has been slow, configuration of the ad-hoc network using the mobile communication terminal has also been delayed. As well, although such IPv6 address is now used, the conventional method still has a drawback in that it cannot handle frequent variations in network topology.

SUMMARY OF THE INVENTION

In order to solve the above problems, the present invention provides an apparatus and method for managing an ad-hoc network that can easily manage frequent variations in network topology.

Provided herein are an apparatus and method for managing an ad-hoc network that can efficiently manage a mobile communication network and an ad-hoc network using a conventional mobile communication network system.

Provided herein are an apparatus and method for managing an ad-hoc network that enables an ad-hoc network to be easily managed and to thus create new beneficial models.

In accordance with an aspect of the present invention, there is provided a method for managing an ad-hoc network of a mobile communication system that provides mobile communication services to one or more mobile communication terminals. The method includes creating an address table that stores addresses of the mobile communication terminals, which are participating in the ad-hoc network, in the mobile communication system, and a routing table that stores routing information among the mobile communication terminals, receiving an address request message from a first mobile communication terminal intended to participate in the ad-hoc network, allocating an address to the first mobile communication terminal in response to the address request and storing the result in the address table, updating the routing table using routing information updated according to the address allocation, receiving topology change information of the ad-hoc network from the first mobile communication terminal, updating the routing table using the topology change information and then transmitting the routing table to the first mobile communication terminal, and transmitting the routing table to other mobile communication terminals participating in the ad-hoc network in which the first mobile communication terminal has participated.

The address table may store identification information of the mobile communication terminals and addresses matched with the identification information. The addresses are allocated to the mobile communication terminals so that the mobile communication terminals can participate in the ad-hoc network.

The identification information of the mobile communication terminals is a Mobile Identification Number (MIN) of the mobile communication terminals.

The routing table stores all routing information with respect to all the mobile communication terminals participating in the ad-hoc network, in which one of the mobile communication terminals, defined as a source, is routed to the others defined as a destination, which is performed for the respective mobile communication terminals.

The routing table may store an address of a source mobile communication terminal, an address of a destination mobile communication terminal, an address of a mobile communication terminal adjacent to the source mobile communication terminal toward the destination mobile communication terminal and the number of hops from the source mobile communication terminal to the destination mobile communication terminal, with respect to all link paths among the mobile communication terminals that exist in the ad-hoc network.

According to the present invention, allocating an address to the first mobile communication terminal in response to the address request and storing the result in the address table, further may include checking subscriber information of the first mobile communication terminal and determining as to whether a user of the first mobile communication terminal subscribes to ad-hoc network services. Here, an address is allocated to the first mobile communication terminal only if the user of the first mobile communication terminal subscribes to the ad-hoc network services based on the determination.

The method may further include, when an ad-hoc network topology change has occurred according to a mobile communication network state change, updating the routing table using information of the topology change, and transmitting the routing table to all the mobile communication terminals participating in the ad-hoc network.

The method may further include billing use cost of the ad-hoc network to the first mobile communication terminal using ad-hoc network use details information periodically transmitted from the first mobile communication terminal.

In accordance with an aspect of the present invention, provided is a mobile communication terminal that includes a user interface unit for inputting a user's ad-hoc network participation request signal for participating in an ad-hoc network, a mobile communication module for communicating with a mobile communication network system providing mobile communication network services and receiving an allocated ad-hoc network address from the mobile communication network system in response to the ad-hoc network participation request signal, an ad-hoc module participating in the ad-hoc network using the ad-hoc network address, and a controller for receiving ad-hoc network use details from the ad-hoc module and periodically transmitting the ad-hoc network use details to the mobile communication network system through the mobile communication module.

The ad-hoc network module outputs a control message for searching for an ad-hoc network participant, and determines ad-hoc network topology change information based on a response message transmitted from another mobile communication terminal having received the control message. Also, the controller transmits the ad-hoc network topology change information to the mobile communication network system through the mobile communication module.

The mobile communication module may receive a routing table, updated by the ad-hoc network topology change information, from the mobile communication network system, and then transmit it to the controller.

The mobile communication module may receive a routing table, updated by another mobile communication terminal participating in the ad-hoc network, from the mobile communication network system, and then transmit it to the controller.

The mobile communication module may receive a routing table, updated by the mobile communication network system itself according to the mobile communication network state change, from the mobile communication network system, and then transmit it to the controller.

The ad-hoc module may be connected to other mobile communication terminals participating in the ad-hoc network, through the ad-hoc network, based on the received routing table.

The mobile communication module may receive cost information according to the ad-hoc network use details from the mobile communication network system and then transmit it to the controller.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the present invention are described in detail with reference to the accompanying drawings. In the drawings, the same or similar elements are denoted by the same reference numerals even though they are depicted in different drawings. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted for the sake of clarity and conciseness.

FIG. 1illustrates a mobile communication terminal according to the present invention. Referring toFIG. 1, the mobile communication terminal100includes a storage unit110, an input unit120, a controller130, a mobile communication module140and an ad-hoc module150.

The storage unit110stores information related to operations of the mobile communication terminal100, such as a drive program for system control and data associated with the drive program. In particular, the storage unit110stores an ad-hoc network address that the mobile communication terminal100requires to participate in an ad-hoc network.

The input unit120interfaces with a user to control operations of the mobile communication terminal100. That is, the input unit120inputs an operation signal from the user to transmit it to the controller130. In particular, the input unit120preferably inputs a user's ad-hoc network participation request signal for participating in the ad-hoc network and transmits it to the controller130.

The controller130controls the mobile communication terminal100based on the signal inputted through the input unit120or a previously stored drive program. For example, the controller130transmits an ad-hoc network address, received through the mobile communication module140, to the ad-hoc module150, or transmits ad-hoc network use details information, transmitted from the ad-hoc module150, to the mobile communication network system through the mobile communication module140.

In particular, the controller130performs periodic transmission of this ad-hoc network use details information. Such periodic transmission enables the mobile communication network system to calculate use cost of the ad-hoc network based the ad-hoc network use details information. That is, as each mobile communication terminal obligatorily transmits its ah-hoc network use details information to the mobile communication network system, the mobile communication network system can charge amounts corresponding to the ad-hoc network use based on the ad-hoc network use details information.

The mobile communication module140communicates with the mobile communication network system that provides mobile communication network services, and receives an allocated ad-hoc network address from the mobile communication network system in response to the ad-hoc network participation request signal. The ad-hoc network address is stored in the storage unit110according to the control of the controller130.

Also, the mobile communication module140receives a routing table from the mobile communication system, updated by a change of information in the ad-hoc network topology, a routing table updated by other mobile communication terminals participating in the ad-hoc network, or a routing table updated by the mobile communication network system itself according to a change in the mobile communication network state, and then transmits it to the controller130.

In addition, the mobile communication module140receives cost information according to the ad-hoc network use details from the mobile communication network system. The mobile communication module140transmits the received cost information to the controller130.

The ad-hoc module150participates in the ad-hoc network using the ad-hoc network address received through the mobile communication module140. The ad-hoc module150outputs a control message for searching for an ad-hoc network participant, and receives a response message outputted from another mobile communication terminal having received the control message. That is, ‘neighbor discovery’ is preferably exchanged therebetween. The ‘neighbor discovery’ refers to an Internet Control Message Protocol (ICMP) message that hosts transmit and receive to and from each other within an ad-hoc group to determine ad-hoc network topology.

Specifically, the ad-hoc module150transmits the ICMP message including information of the mobile communication terminal100(e.g., Mobile Identification Number (MIN) or Electronic Serial Number (ESN)) over the ad-hoc network. If a response message is received in response to the ICMP message, the ad-hoc module150determines a transmitter having transmitted the response message. That is, the ad-hoc module150determines that the transmitter is participating in the same ad-hoc network.

When the ad-hoc network participant changes, it is determined that ad-hoc network topology changed. Therefore, the controller130transmits the information of the changed ad-hoc network topology to the mobile communication network system through the mobile communication module150.

Also, the ad-hoc module150is preferably connected to other mobile communication terminals, participating in the ad-hoc network, through the ad-hoc network based on the routing table received thorough the mobile communication module140.

FIG. 2A-2Billustrate a procedure for managing an ad-hoc network according to the present invention, in which the ad-hoc network including the mobile communication terminal100ofFIG. 1as a node is managed by a mobile communication network system.

As shown inFIG. 2A-2B, the mobile communication network system includes a base station200providing mobile communication services to the mobile communication terminal100, an IP address administration server300managing IP addresses to be used in the ad-hoc network, and a Home Subscription Server (HSS)400. Here, the IP address administration server300preferably stores an address table (not shown) for storing addresses of mobile communication terminals participating in the ad-hoc network, and a routing table310for storing routing information between mobile communication terminals over the ad-hoc network.

Referring toFIGS. 1 and 2, the method for managing an ad-hoc network according to the present invention will be described as follows.

When the mobile communication terminal100requests an IP address to be used in an ad-hoc network (S202), the base station200transmits the request message to the IP address administration server300(S204). The IP address administration server300requests subscriber information from the HSS400(S206). Here, the HSS400refers to an apparatus that manages information about subscribers to mobile communication network services. The HSS400manages personal information, mobile communication terminal information, additional service subscription information and billing information of subscribers. To manage the subscriber information, the subscriber information table stored in the HSS400is described inFIG. 3, and will be described later in detail.

Also, the request of subscriber information from the HSS400in S206is to determine whether the user of the mobile communication terminal100subscribes in the ad-hoc network service.

When receiving the subscriber information on the user of the mobile communication terminal100from the HSS400(S208), the IP address administration server300analyzes it and then determines whether the ad-hoc network is available to the user (S210). If the user cannot use the ad-hoc network, as determined in S210, the IP address administration server300notifies the mobile communication terminal100that the ad-hoc network is not available (S211). If the user can use the ad-hoc network, as determined in S210, the IP address administration server300allocates an IP address to the mobile communication terminal100(S212), and then transmits it to the mobile communication terminal100via the base station200(S214, S216). After that, the IP address is registered in an address table (not shown), associating with identification information of the mobile communication terminal100, and then a routing table310is updated using routing information (S222), which was updated according to the allocated address. Here, the address table and the routing table310are illustrated inFIGS. 4 and 5, respectively, and will be described later in detail.

When receiving the IP address participating in the ad-hoc network via the base station200, the mobile communication terminal100searches for an ad-hoc network participant that is using it (S218). To this end, the mobile communication terminal100preferably outputs a control message to search for an ad-hoc network participant, and receives a response message from another mobile communication terminal having received the control message. That is, the ‘neighbor discovery’ is exchanged therebetween, as discussed above with respect toFIG. 1.

Specifically, the ad-hoc module150transmits the ICMP message including information of the mobile communication terminal100over the ad-hoc network. If a response message is received in response to the ICMP message, the ad-hoc module150determines a transmitter having transmitted the response message. That is, the ad-hoc module150determines the transmitter as a participant in the same ad-hoc network. When the ad-hoc network participant changes, it is determined that ad-hoc network topology changed.

When detecting the topology change from the determination (S220), the mobile communication terminal100notifies the IP address administration server300of the topology change through the base station200(S224, S226). The mobile communication terminal100preferably transmits information of the topology change to the IP address administration server300, as well.

Next, the IP address administration server300updates the routing table310using the topology change information (S228) and then transmits it to the mobile communication terminal100via the base station200(S230, S232).

The base station200preferably transmits the routing table310to other mobile communication terminals participating in the ad-hoc network in which the mobile communication terminal100has participated.

If an event has occurred (S234), the base station200notifies the IP address administration server300of the event (S236). Here, the event refers to a cause of a change in ad-hoc network topology from the mobile communication network, and cites examples, such as traffic relocation according to the time of a call, or off state detection of a mobile communication terminal that is participating in the ad-hoc network. The base station200preferably transmits the topology change information due to the event to the IP address administration server300, together with the event.

Next, the IP address administration server300updates the routing table310using the topology change information (S238), and then transmits it to the mobile communication terminal100via the base station200(S240, S242). The base station200preferably transmits the routing table310to other mobile communication terminals participating in the ad-hoc network in which the mobile communication terminal100has participated.

When receiving ad-hoc network use details from the mobile communication terminal100(S244), the base station200requests subscriber information on the mobile communication terminal100from the HSS400(S246) and then receives the subscriber information from the HSS400in response to the request (S248). After that, the base station200calculates cost based on the subscriber information and the ad-hoc network use details information transmitted from the mobile communication terminal100(S250). The process of S250is to determine the use cost, which the mobile communication terminal100has accumulated in the ad-hoc network, to charge to the user of the mobile communication terminal100.

Here, the subscriber information of the user of the mobile communication terminal100is requested such that the cost can be calculated according to users' service subscription conditions.

After that, the base station200notifies the HSS400and the mobile communication terminal100of the calculation result of S250(S252, S254).

The HSS400manages the cost according to subscriber information of the corresponding subscriber. For example, the HSS400associates the cost with subscriber information of the corresponding subscriber, thereby managing the cost payment details information of the corresponding subscriber.

Then, the mobile communication terminal100bills the corresponding subscriber, so that the subscriber can pay.

As such, since the present invention is configured to allow the mobile communication network system to manage the ad-hoc network using the mobile communication terminal100, the network can be collectively managed. Also, since the present invention is configured to receive topology detection results from each mobile communication terminal, frequent changes in network topology are easily managed.

FIG. 3illustrates a subscriber information table for managing an ad-hoc network according to the present invention, which is stored in the HSS400ofFIG. 2A-2B.

Referring toFIG. 3, the subscriber information table410stores information (e.g., MIN, and ESN) for identifying subscribers, indicating whether a corresponding subscriber uses an ad-hoc network, and indicating cost according to user's ad-hoc network use.FIG. 3shows information about users whose phone numbers are 010-1234-5678, 010-1112-7775 and 010-1235-1111, respectively. As shown inFIG. 3, only the users of 010-1234-5678, and 010-1235-1111 are using the ad-hoc network, and have cost information of 386 and 1,050, respectively. Here, the cost information is preferably created as an amount of transmission/reception data or time of access to the network is accumulated for a certain period.

It will be appreciated that the subscriber information is not limited by the embodiment ofFIG. 3. That is, the subscriber information may further include information about additional services' that a corresponding subscriber subscribes to and the subscriber's personal information, such as the date of the subscriber's birth.

FIG. 4illustrates an ad-hoc network address table according to the present invention. The address table preferably stores identification information of the mobile communication terminals and addresses matched with the identification information, in which the addresses are allocated to the mobile communication terminals so that they may participate in the ad-hoc network. Also, the identification information of the mobile communication terminals is preferably a MIN of the terminals. In the address table320ofFIG. 4, the identification information of the mobile communication terminals employs the MIN with which IP addresses are matched.

FIG. 5Aillustrates a routing table for providing routing paths among ad-hoc network participants according to the present invention. The routing table preferably stores all of the routing information with respect to all the mobile communication terminals participating in the ad-hoc network. That is, one of the mobile communication terminals, defined as a source, is routed to the others defined as a destination, which is performed for the respective mobile communication terminals. Also, the routing table stores such information as an address of a source mobile communication terminal, an address of a destination mobile communication terminal, an address of a mobile communication terminal adjacent to the source mobile communication terminal toward the destination mobile communication terminal, and the number of hops from the source mobile communication terminal to the destination mobile communication terminal, with respect to all link paths among the mobile communication terminals that exist in the ad-hoc network.

Referring toFIG. 5A, with respect to the respective mobile communication terminals A, B, and C that participate in the ad-hoc network, there are paths where the respective mobile communication terminals are sources and another mobile communication terminal D is a destination. Also, the table stores an address of the mobile communication terminals adjacent to the destination mobile communication terminal D, and stores the number of hops.

FIG. 5Bdescribes a routing process according to the routing table ofFIG. 5A. As shown inFIG. 5B, when the first mobile communication terminal51is ‘A’ ofFIG. 5A, the second mobile communication terminal53is ‘B’ ofFIG. 5A, the third mobile communication terminal55is ‘C’ ofFIG. 5A, and the fourth mobile communication terminal ‘D’ ofFIG. 5A, ad-hoc network is linked along the arrows ofFIG. 5Aaccording to the routing information illustrated inFIG. 5B.

That is, if the ad-hoc network is linked from the first mobile communication terminal51to the fourth mobile communication terminals57, the links are achieved through the second and third mobile communication terminals53and55, in which the number of hops is 3.

In the embodiments of the present invention, since all of the network management is performed in the mobile communication network system as shown inFIG. 2A-2B, the ad-hoc network is systematically and conveniently managed.

As described in the foregoing, the present invention has the following advantages:

Since the ad-hoc network is managed using the mobile communication network system, the mobile communication network and the ad-hoc network are all effectively managed. Also, since topology change information transmitted from the respective mobile communication terminals is collected and, managed in the mobile communication network system, frequent change of network topology can be easily managed. Furthermore, since ad-hoc network use, details of the respective mobile communication terminals are managed in the mobile communication network system, users are billed according to the use details. That is, the present invention allows mobile communication service providers to create new beneficial models.