Background Art With fast increase in population using Internet, Information SuperHighway is being rapidly spread among many households. In addition, according to such a trend, many companies are introducing various information home appliances into the market. The information home appliances mean digital home appliances having a network communication function additionally so that a user can access to the Internet through the home appliances in a home. As the information home appliances with a communication function play a role as information terminals, a network for communications between home appliances or between home appliances and information terminals in a home is being constructed. Such a network is called a home network or a home area network. Practically, in order to establish such a home network, various network protocols based on various protocols such as IP, Bluetooth, IEEE1394, and LonTalk have to be employed.

However, it is not easy for information terminal users in a home to understand the

protocols and to construct a network.

In addition, internet service providers (hereinafter referred to as"ISPs") generally assign a different internet address to a subscriber, for example, a home, every time the subscriber accesses to the Internet and, therefore, the user can not access from outside to a home network.

In other words, under the Internet communication environment, each computer globally connected through networks exchanges data with other computers according to mutual common rules and, therefore, each computer connected to the Internet needs a specific address by which each computer can be distinguished from other computers on the Internet. However, in case of accessing to the Internet through a modem, a computer is given a different IP address by the ISP every time it accesses to the Internet, and, therefore, external users cannot know the changed IP address. Even so, it is impossible for each of all information appliances in a home to have a unique IP address because the number of IP addresses is deficient under the present IP address format.

The specific address on the Internet is expressed by means of numeric figures or English letters. The address expressed by means of numeric figures, what is called an IP address, is an address for computers by which a computer can easily look for a specific computer among communication devices connected to a communication network. The address expressed by means of English letters, what is called a domain name, is an address for users by which a user can easily understand an address of a computer on the Internet. In addition, each communication device connected to the Internet has to have a unique address that is not redundant globally with any other device in both the IP address and the domain name.

First, if a user inputs a domain name through a web browser, the web browser queries an IP address corresponding to the domain name to a domain name server through the Internet. The domain name server searches its own database responding to the request of the web browser and, then, provides the IP address corresponding to the domain name. Subsequently, the web browser exchanges data with a web server having the domain name using the IP address received. Here, a domain name system (hereinafter referred to as"DNS") is used to change a domain name into an IP address. In order to be used by other users on the Internet, a domain name associated with an IP address has to be registered on a DNS server that is authorized on the Internet. Thus, an IP address corresponding to a domain name is required in a domain name service. If an IP address of a device changes each time, it is impossible to provide the domain name service and to access to a home network from outside accordingly.

Another problem in constructing a home network is that a plurality of network terminals cannot share an authorized IP address on the Internet.

Moreover, in order to construct a home network in a home, a user has to set up information about a network structure and service servers by himself/herself, but it is not easy for general users with little knowledge about network to understand protocols and constitute a server.

Devices connected to home networks have a characteristic address hierarchy on each network. The characteristic address hierarchy on each network is not compatible with each other and, therefore, a device in a network can transmit a signal to a device in another network only through a home gateway system. Here, the home gateway system converts a signal in a network into a form acceptable in a destination network. In another aspect, the home gateway

system converts a signal in a network into a known existing form to transmit'the signal and the signal transmitted is converted into a form acceptable in the destination network.

As a prior art, U. S. Patent No. 5,852, 660, Lindquist et al. , discloses a network protocol conversion module within a telecommunications system. The above-mentioned U. S. patent provides a method and apparatus for enabling telecommunications signals containing application layer data generated by a first SS7 (Signaling System No. 7) telecommunications network to be transported across a second SS7 telecommunications network, wherein the first SS7 telecommunications network and the second SS7 telecommunications network are incompatible. However, such a conventional method has a problem that protocol conversion is performed using a physical device, thereby causing inconvenience due to installation of the physical device. Therefore, a need exists for methods of performing protocol conversion using logical address conversion between protocols.

Conventional address conversion methods for communications between various protocols are closely related to a protocol conversion process. Therefore, address conversion methods according to protocol conversion methods are classified into three classes.

First, there is an address conversion method in 1 to 1 protocol conversion.

This method converts an address used at a particular protocol layer into an address required at a corresponding layer of another protocol, based on the seven- layered OSI reference model. However, for data exchange between various network protocols having various protocol layers, a lot of conversion methods are required and, therefore, there are problems that a home gateway accepting various

protocols has to manage a very large address table and treat complicated conversion processes.

Second, there is an address conversion in a method of converting into a particular protocol. This address conversion method converts n network protocols into a particular network protocol selected from the n network protocols. In order to convert n network protocols into a particular protocol, (n-1) conversion methods are required and, therefore, (n-1) address conversion methods are required. Although this address conversion method shows reduction in complexity and size of address table compared to the first method, it still requires a lot of address conversion.

Third, there is an address conversion in a method of utilizing an overlay way. For example, it is IP-over-IEEE1394, IP-over-ATM, and so on. There are structures that an Internet protocol, IP, is laid on an IEEE1394 or ATM layer.

They do not perform particular conversions and are not data exchange methods between network protocols. In other words, in the IP-over-IEEE1394, an apparatus in an IEEE 13 94 network transmits IEEE1394 data laid on the IP and receives data through the IP. The data received through the IP is passed through the IEEE1394 layer so that the IEEE1394 apparatus can accept the data.

Therefore, it cannot be referred to as data exchange between different network protocols.

For example, U. S. Patent No. 5,715, 250, Watanabe, discloses an ATM- LAN (asynchronous transfer mode local area network) connection apparatus capable of connecting terminals of different protocol standards. The U. S. patent provides a small-scale ATM-LAN connection apparatus which enables communications between first and second ATM terminals of different standards,

namely, the first ATM terminal of a LAN emulation protocol and the second ATM terminal of an IP over ATM protocol.

However, the above-mentioned address conversion methods increase complexity and size of address table because the number of address conversion methods increases in proportion to the number of network protocols to be converted and the number of layers in the network protocols to be converted. In addition, when the address conversion is performed, the complexity increases according to the number and structure of packets that are related to address mapping at each protocol layer, e. g. , ARP and ping, because the protocol layer architecture and role of each layer in each network protocol are very different from each other based on the seven-layered OSI reference model.

Disclosure of Invention Accordingly, the present invention is directed to an architecture of a common address and an address table for transferring data between different network protocols and a constructing method thereof, which substantially obviate one or more problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a method of communication of different networks with each other using application programs only, without address conversion between existing protocol layers, by designing a common address structure usable in a common protocol layer and using a common address of a common protocol layer in or under an application layer.

Another object of the present invention is to provide a method of identifying whether devices in different networks are working and a new device is installed in the networks and identifying types of devices and protocols used in

the devices only through a common address.

Another object of the present invention is to provide an address table which supports rapid mapping between a physical address and a common address (logic address) on each network.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve the objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the present invention provides a structure of a common address for transferring data between different network protocols, wherein the structure being used for understanding different addresses of different protocols in a common protocol layer which enables different networks to communicate with each other by accepting various protocols of a home network system comprising at least two networks with different source coding methods and transfer speeds, the structure of a common address comprising: a domain address including information about a network ; a cluster address including information about devices using the same protocol in the network; a device use address (category address #1) including information about use of a device in the network ; a device type address (category address #2) including information about a

type of a device in the network; a device ID including information about a specific number assigned to each device in the network ; and a reserved field for use in address extension in a future.

In addition, the present invention provides a method of constructing a common address for transferring data between different network protocols, wherein the method for understanding different addresses of different protocols in a common protocol layer which enables different networks to communicate with each other by accepting various protocols of a home network system comprising at least two networks with different source coding methods and transfer speeds, the method comprising the steps of : forming a domain address including information about a network; forming a cluster address including information about devices using the protocol in the network ; forming a device use address including information about use of a device in the network; forming a device type address including information about a type of a device in the network; forming a device ID including information about a specific number assigned to a device in the network ; and forming a reserved field for use in address extension in a future.

In another aspect, the present invention provides an address table structure for transferring data between different network protocols as a structure to support rapid mapping between a common address (logic address) and a physical address of each network device, the address table structure comprising:

an address table memory capable of storing a physical address of a network device in an address space in an external memory of a home station chipset; and an address table controller for finding out a physical address corresponding to a common address (logic address) of a network device from the address table memory.

In addition, the present invention provides a method of constructing an address table for transferring data between different network protocols, as a method to support rapid mapping between a common address (logic address) and a physical address of a network device, the method comprising the steps of : transferring a common address (logic address) of a network device from an external interface of a home station to an address table controller in a home station chipset; finding out an address space containing a physical address corresponding to the common address from an external memory of the home station chipset; taking out the corresponding physical address from the address space; and transferring the physical address to the address table controller.

In another aspect, the present invention provides a method of registering a device adopting a common protocol for transferring data between different network protocols, as a method of registering a device using a common protocol in a common protocol layer which enables different networks to communicate with each other by accepting various protocols of a home network system comprising at least two networks with different source coding methods and transfer speeds, the method comprising: a first step of initializing an address table when power of a device is turned

on; a second step of sending a device registration request packet to a home station after the device begins to work and waiting for a device registration response packet from the home station for a predetermined time; a third step of setting a domain address and a device ID, storing an address table, and working normally so as to inform users of devices connected to a home network, if the device has received the device registration response packet ; and a fourth step of waiting until the home station is turned on and returning to the second step after receiving an HRIND packet from the home station, if the device has not received the device registration response packet.

In addition, the present invention provides a method of registering a home station of devices adopting a common protocol for transferring data between different network protocols, as a method of registering a home station using a common protocol in a common protocol layer which enables different networks to communicate with each other by accepting various protocols of a home network system comprising at least two networks with different source coding methods and transfer speeds, the method of comprising: a first step of initializing an address table when a home station begins to work ; a second step of sending an HRREQ packet ; a third step of setting the address table if an HRRES packet is received for a first predetermined time; a fourth step of checking whether the HRRES packet has been received or not after the first predetermined time; a fifth step of setting an unused number as a domain address if the HRRES

packet has been received; a sixth step of setting an initial value as the domain address if the HRRES packet has not been received; and a seventh step of sending an HRIND packet and working normally.

Brief Description of the Drawings Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which: Fig. 1 is a structure chart illustrating a common address structure of a common protocol according to the present invention; Fig. 2 is a view for describing a domain address of a common address according to the present invention; Fig. 3 is a view for describing a cluster address of a common address according to the present invention; Fig. 4 is a table consisting of a device use address and a device type address; Fig. 5 is a view for describing an example of transferring data to another network according to the present invention; Fig. 6 is a structure chart illustrating an overall address table structure according to the present invention; Fig. 7 is a structure chart illustrating a partition structure of an address table; Fig. 8 is a structure chart illustrating a partition header structure;

Fig. 9 is a flow chart illustrating a process of assigning a device ID; Fig. 10 is a view for describing an example of a device registration process; Figs. lla and llb are views for describing an example of a device registration packet; Fig. 12a and 12b are views for describing an example of a device registration process; Fig. 13 is a view for describing an example of a home station registration process; Figs. 14a through 4e are views for describing an example of a home station registration packet ; and Figs. 15a through 15d are views for describing an example of a practical use of HRSREQ, HRSRES, HRREQ, and HRRES packets.

Best mode for Carrying Out the Invention Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

Fig. 1 is a structure chart illustrating a common address structure of a common protocol according to the present invention. Major features of a common address according to the present invention are that the common address can be understood only through a common protocol layer and that types of devices used in another network can be clearly identified through each field of the common address using a simple application program because the common protocol layer is positioned in or under an application layer. Another feature of the common

address is that it distinguishes the same type of maximum fifteen devices. As shown in Fig. 1, the common address of the present invention is 3 bytes in size and comprises 6 fields such as a domain address (10), a cluster address (20), a device use address (30), a device type address (40), a device ID (50), and a reserved field (60).

Fig. 2 is a view for describing the domain address (10) of the common address according to the present invention. The domain address, first field of the common address, occupies 4 bits of [23: 20] among the whole common address [23: 0]. Here, the domain means a network comprising a home station and, therefore, a home station is assigned one domain address. In addition, all devices in a domain network have the same domain address. Fifteen home stations can be distinguished from values of the domain address from"0001"to"1111".

Therefore, maximum 15 home stations can be installed in a home.

Fig. 3 is a view for describing the cluster address (20) of the common address according to the present invention. The cluster address occupies 4 bits of [19: 16] among the whole common address [23: 0]. The cluster means a network that comprises devices using the same protocol and is connected to a home station, i. e. , a domain network. Therefore, a domain network can comprise maximum 15 cluster networks (except"0000") that adopt different network protocols.

Fig. 4 is a table consisting of the device use address (30, category 1 address) and the device type address (40, category 2 address) in the common address according to the present invention. Referring to Fig. 4, the device use address (30) occupies 4 bits of [15: 12] among the whole common address [23: 0] and indicates a use of a device in a network. The device type address (40) occupies 4 bits of [11: 8] among the whole common address [23: 0] and indicates a

type of a device in a network. For example, a device use and type address of an electric meter reading system capable of telemetering is"0011 0000".

The device ID occupies 4 bits of [7: 4] among the whole common address [23: 0]. The device ID is a specific number assigned to each device in a home station supporting a common protocol. Based on combination of the 4 bits, 16 devices having the same use and type can be used in the same domain, but practically 15 devices (except"0000") are used. "0000"is used for address table management. The reserved field occupies 4 bits of [3: 0] among the whole common address [23: 0]. The reserved field will be used for address extension hereafter.

Fig. 5 is a view for describing an example of transferring data to another network according to the present invention. In Fig. 5, a device AA in a network A transfers data to a device BA in a network B. First, data generated from an application layer of the device AA is passed through a common protocol layer where a common protocol header is attached to the data and a destination address in the header is set as a common address of the device BA. The common protocol layer cannot understand a physical address of the device BA used in the network B because the common protocol layer uses only a common address. A packet with the common protocol header is passed through lower layers. Here, the packet is set so as to have a physical address of a device AZ, an external interface of a home station chipset, in a data link layer and is passed through a physical layer to arrive at the device AZ.

Next, in the device AZ, the packet received is passed from lower layers to a common protocol layer in sequence. In the common protocol layer, the device AZ identifies a fact that the packet received has a preamble and transfers the

packet to the home station chipset. The home station chipset switches the packet to a corresponding port after identifying only the domain address in the destination address.

When the packet arrived at a device BZ is passed through a data link layer, the device BZ cannot know a destination of the packet. Therefore, the device BZ has to convert the common address in the common protocol header into a physical address. For such an address conversion, each of all external interfaces of the home station chipset has to have a physical address table through which each external interface can find out a physical address corresponding to a common address. However, that all the external interfaces manage the same address table may be a waste of resource and to manage such an address table is not easy.

Therefore, the home station chipset manages the address table and transfers a corresponding physical address together with the common protocol packet to the external interface.

Fig. 6 is a structure chart illustrating an overall address table structure according to the present invention. As shown Fig. 6, the address table uses an external memory of a home station chipset (70). One address space in the memory can store a physical address of 6 bytes. The size of the address space is based on an MAC address of 6 bytes, a physical address used in Ethernet and Bluetooth. The common address of 24 bits is entered into the address table memory as it is. In other words, if a common address is entered, a physical address corresponding to the common address is outputted through a data bus of the memory.

Fig. 7 is a structure chart illustrating a partition structure of the address table according to the present invention. Referring to Fig. 7, the external memory

of the address table is naturally partitioned because an address inputted into the address table memory is a common address.

A partition means an area of upper 16 bits in the memory comprising the domain address, the cluster address, the device use address, and the device type address among the common address of 24 bits. The partition and the device ID are defined as a partition ID (hereinafter referred to as"PID"). Therefore, one partition has 15 spaces capable of storing 15 physical addresses corresponding to device IDs. Here, device ID"0000"is used as a partition header to manage the 15 spaces. Therefore, one partition is filled with 15 device IDs (except"0000") each of which is 4 bits in size. For example, as shown in Fig. 7, PID of"0001 0011 0000 0000"means a household refrigerator connected to Ethernet HS#1. As above-mentioned, "0000"is not allotted as a device ID. Instead, the"0000"is used as a space to store information about the partition in the address table. The space is defined as a partition header. Therefore, an address of each of the partition headers becomes"XXXX XXXX XXXX XXXX 0000" (X = don't care).

Here, "XXXX XXXX XXXX XXXX"is PID.

Fig. 8 is a structure chart illustrating a partition header structure. Referring to Fig. 8, the partition header comprises a total number of devices part (80) of 2 bytes and an indication flags part (90) of 2 bytes. The total number of devices part indicates the number of devices using the same PID. The indication flags part indicates whether a device ID has been assigned or not. The indication flags part is used to find out promptly a device ID for a new device when the new device is connected to a network.

Fig. 9 is a flow chart illustrating a process of assigning a device ID. When a new device is connected to a network and requests a device ID, a home station

assigns a device ID to the new device using information in a partition header according to the procedure in Fig. 9. In detail, If a new device requests a device ID, the home station finds PID and a physical address in the address table (S10), reads indication flags in the partition header (S20), and stores"1"in the indication flags pointer (S30). The home station identifies whether a value of the indication flags is"0"or not (S40). If the value of indication flags is"0", the home station gives a device ID to the new device (S50) and updates values of the total number of devices part and indication flags part in the partition header (S60).

Then, the home station stores a physical address of the new device in an address space comprising the PID and the device ID and ends the process of assigning a new device ID to a new device (S70).

If a value of the indication flags is not"0" (S40), the home station adds "1"to the indication flags pointer (S80) and identifies whether a value of the indication flags pointer is equal to or less than 15 (S90). If the value of indication flags pointer is equal to or less than 15, the process returns to S40. If the value of indication flags pointer is more than 15, the home station indicates"Too many devices!" (S 100).

There is described a method of registering a device according to a device constitution change in a home network. Among fields of a common address, a cluster address, a device use address, and a device type address are fixed according to features of a device. However, a domain address and a device ID can change according to change of a home network structure, movement of devices, or movement of users. Whenever such changes occur, a new domain address and a device ID are assigned to the device and the network. Here, when a user simply transfers a device or a home station and turns on the device, the device or the

home station has to be able to assign or be assigned its own domain address, its own cluster address, and its own device ID automatically so that a PnP function can be provided. Particularly, management packets of a common protocol can support the PnP function. To support the PnP function, a common protocol defines procedures of registering a device and a home station to set each device ID and domain address.

Fig. 10 is a view for describing an example of a device registration process.

Referring to Fig. 10, if a device is turned on, an address table of the device is initialized (100). When the device begins to work (110), it sends a device registration request (hereinafter referred to as"DRREQ") packet to a home station (120) and waits for a predetermined time in order to receive a response (130). If the home station does not send a response, the device considers that the home station is turned off (140), and waits (150) until the home station is turned on, i. e. , until a home station registration indication (hereinafter referred as to "HRIND") packet is received (160). If the device receives a device registration response (hereinafter referred to as"DRRES") packet (170), it sets its own domain address and device ID and stores an address table loaded on a payload (180). Then, the device works normally to inform the user of devices connected to the network (190). If the device receives the HRIND packet (200), it repeats the processes from 110 to 190.

Figs. lla and llb are views for describing an example of a device registration packet. Each device adopting a common protocol is assigned a domain address and a device ID according to the procedure as shown in Fig. 10 and, in the procedure, a DRREQ packet (210) and a DRRES packet (220) as shown in Fig. 11 are used.

Fig. 12a and 12b are views for describing an example of a device registration process. Referring to Fig. 12a, Case 1 is when a device sets a domain address and a device ID normally after receiving the DRRES packet as a response to the DRREQ packet. Referring to Fig. 12b, Case 2 is when a device has not received the DRRES packet because power of a home station is turned off.

Thereafter, if the home station is turned on, sets a domain address through a home station registration procedure, and sends the HRIND packet to the device, the device sends again the DRREQ packet to the home station and receives the DRRES packet from the home station to set a domain address and a device ID.

There is described a method of registering a home station. Registration of a home station means a series of processes where domain addresses for a new domain network are determined when a new home station logs on a home network or an existing home station is turned on. Here, the user needs not to set the domain address individually and the home station can determine its own domain address by itself through message exchange with other home stations.

Fig. 13 is a view for describing an example of a home station registration process. With the start of a new home station, an address table of the home station is initialized (300). The home station sends a home station registration start request (hereinafter referred to as"HRSREQ") packet (320) and waits for a predetermined time, preferably 3 seconds, to receive a response (320). If the home station receives a home station registration start response (hereinafter referred to as"HRSRES") packet (330), the procedure of registering a new home station is completed (350) after a predetermined time, preferably 5 seconds (340).

In the step 320, if the home station has not received the HRSRES packet, the home station sends a home station registration request (hereinafter referred to

as"HRREQ") packet (360) and waits for a predetermined time, preferably 5 seconds (370). If the home station receives a home station registration response (hereinafter referred to as"HRRES") packet within the 5 seconds (390), the home station sets its own address table (400). If the home station receives the HRSREQ packet while setting the address table (400), the home station sends the HRSRES packet (410) and returns to the step 370. If the home station receives the HRSREQ packet during the step 370, the home station sends the HRSRES packet (380). After a predetermined time (420), the home station checks whether the HRRES packet is received or not (430). If the HRRES packet is not received, the home station sets"1"in a domain address (460). If the home station receives the HRSREQ packet while setting"1"in the domain address, the home station sends the HRSRES packet (470). After completing to set"1"in the domain address, the home station sends the HRIND packet (480) and works normally (530).

If the home station receives the HRREQ packet while operating normally, the, it sends the HRRES packet (540). Also, if the home station receives the DRREQ packet (550) while operating normally (530), the home station assigns a device ID to a device, sets its own address table (560), and sends a DRRES packet to the device (570).

In the step 430, if the HRRES packet has been received (490), the home station sets an unused number as its own domain address (500). If the home station receives the HRSREQ packet while setting the domain address, the home station sends the HRSRES packet (510). After completing to set the domain address, the home station sends the HRIND packet (520) and works normally (530).

Figs. 14a through 14e are views for describing an example of a home

station registration packet. The HRSREQ packet (600) is a packet which a new home station sends to existing home stations already logged on to a home network when the new home station wants to log on to the home network. This packet is sent in order to identify whether another home station performs a registration procedure or not. This is for preventing more than one home station from being assigned the same domain address almost simultaneously. If the home station does not receive a response within a predetermined time after sending the HRSREQ packet, the home station practically begins an actual registration procedure.

The HRSRES packet (610) is a response packet to the HRSREQ packet. If a first home station receives the HRSREQ packet from a second home station whiling performing the registration procedure, the first home station sends the HRSRES packet to the second home station in order to request to start a registration procedure a little later.

The HRREQ packet (620) is used to inform other home stations that a home station will perform a registration procedure. The HRRES packet (630) is a response packet to the HRREQ packet. If a home station receives the HRRES packet after sending the HRREQ packet, the home station sets its own address table using address information in a payload of the HRRES packet and, after a predetermined time, sets its own domain address using domain address information received from other home stations.

If a home station receives an HRREQ packet while operating normally after completion of the registration procedure, the home station sends the HRRES packet (630) with a payload containing an address table for devices in its own domain network. The HRIND packet (640) is used to inform devices in

the same domain network of a domain address. For example, a home station collects the HRRES packets for a predetermined time, sets its own domain address, and sends the HRIND packet to devices in the domain network. The devices in the domain network can request its own device ID after receiving the HRIND packet.

Figs. 15a through 15d are views for describing an example of a practical use of HRSREQ, HRSRES, HRREQ, and HRRES packets. Case 1 is when a home station sends the HRSREQ packet, receives the HRSRES packet within 3 seconds, waits for 5 seconds, and, then, sends again the HRSREQ packet. Case 2 is when the home station sends the HRSREQ packet, waits for 3 seconds, and sends the HRREQ packet in order to begin a registration procedure because the home station has not received any HRSRES packet within 3 seconds. Case 3 is when the home station sends the HRREQ packet, receives the HRRES packet within 5 seconds, sets its own address table, and, after 5 seconds, sets its own domain address. Case 4 is when the home station sets its own domain address as"1"because it has not received any HRRES packet for 5 seconds.

Industrial applicability Accordingly, by being designed so as to be used in a common protocol structure to perform smooth data communications between various network protocols, a common address and an address table for transferring data between different network protocols according to the present invention can enhance compatibility between network protocols and enable communication of different networks with each other using only application programs without address conversion between existing protocol layers. In addition, the present invention

can identify whether devices in different networks are working and a new device is registered, identify types of protocols and devices used, and support rapid mapping between a physical address and a common address. The present invention is applicable to various applications requiring communications between different protocols, protocols of home server and home gateway accepting various protocols, and a compatibilization method between protocols having different protocol layer architectures.