KR100603938B1 - Comunication system capable of selecitve receiving in administrative domain - Google Patents

Abstract

The present invention provides a communication system suitable for a ubiquitous computing environment.

The communication system of the present invention

A network unit configured to divide a portion of a multicast address block in a management area among the multicast address areas by dividing the block, and set the network to transmit data without separate group management for all data received through the designated address area; And

Comprising a list of the address of the group to receive the data, and when the data is received, including the receiving terminal for comparing the group address of the received data with the address list of the group to receive the data to determine whether to receive the data; It includes a communication system.

Description

COMCOMICATION SYSTEM CAPABLE OF SELECITVE RECEIVING IN ADMINISTRATIVE DOMAIN}

1 shows a schematic flow of a communication method of the present invention.

2 illustrates an implementation example of a router setting network unit.

3 illustrates an implementation example of an access point setting network unit.

4 is an implementation diagram showing selective reception at a receiving terminal.

The present invention relates to a communication system used for ubiquitous computing and a communication method using the communication system.

With the development of wireless communication technology and the development of electronic technology including semiconductors, the era of ubiquitous computing that can provide desired computing service anytime and anywhere is opening. The most important feature of the ubiquitous computing era is that a large number of information sources are scattered around them, and they provide various information to the user or the user's terminal. Of course, information provided by one information source is often desired by more than one user at the same time.

When multiple users simultaneously receive information from one information source, it is common to use a multi-transmission technique such as multicast in order to avoid inefficiency of network resource usage caused by sending the same information repeatedly. Unlike the one-to-one communication, the multi-transmission technique requires additional membership management techniques to find and manage the users to be received because the users to be received are scattered in the network.

For multicast over the Internet, the Internet Group Management Protocol (IGMP) is commonly used. However, when the multicast technology based on the Internet group management protocol is applied to a ubiquitous computing environment in which a large number of information sources continuously provide information, there is a problem of deterioration of service quality due to delay in participation and large overhead of group management. have.

In the TCP / IP (network control protocol / Internet protocol) -based network environment, the technologies that can be used to provide information to multiple users from multiple information sources are unicast and multicast ( multicast and broadcast. The characteristics of these techniques are as follows.

Unicast technology is a method in which the sender and receiver of information form a one-to-one correspondence, which is the most commonly used communication method on the Internet. However, when there are a large number of users who need to receive data, unicast is repeatedly transmitting the same information through several different connections, which wastes network resources. Therefore, if there are multiple receivers, use multicast technology rather than unicast.

Multicast technology is a communication method that delivers one transport packet to one or more receivers. From the viewpoint of network resources, the multicast technology reduces transmission of redundant information, thereby efficiently utilizing resources. However, unlike unicast, in which the relationship between the sender and receiver is clearly determined, in the case of multicast, a separate protocol is required for efficient transmission by tracking and understanding who is the sender and where it is currently connected. Currently, the Internet Group Management Protocol (IGMP) has been standardized and used.

The multicast method has a merit that a plurality of users can receive it at the same time, but for this, administrative measures such as allocating addresses to distinguish each multicast group are necessary.

The broadcast method is a communication method in which all connected hosts can receive information, and is used when information needs to be sent immediately to an unspecified user. For example, in the case of Dynamic Host Configuration Protocol (DHCP), a protocol for dynamically distributing configuration information of a host including an address, the host that wants to receive the configuration information does not know the address of a DHCP server to provide the information in advance. You will be asked for information.

However, when the above unicast, multicast, and broadcast technologies are applied to a ubiquitous computing environment (applications in which multiple users simultaneously receive information from multiple information sources), the following problems occur.

In the ubiquitous computing environment, since the majority of user terminals are wireless terminals, the communication between the information source and the information receiver uses a wireless technology. At this time, all transceivers share and use a given frequency band.

In this situation, when multiple sources of information use unicast for an application that simultaneously delivers information to multiple users, the same information is duplicated through shared network resources. This redundant delivery raises two problems.

First, since the same information must be transmitted in duplicate, the utilization efficiency of network resources is reduced, and thus all transceivers can receive a low quality network service.

The second problem is that each receiver must at least receive the address portion of all transport packets and consume power in order to determine whether the packets transmitted through the shared bandwidth come to them. In the ubiquitous computing environment, considering that the majority of user terminals depend on the battery, a method that requires a lot of received energy is not appropriate. Thus, unicast technology is not suitable for this application.

If multicast technology is used for the above application, instead of sending the same packet repeatedly, duplicates are defined because all receivers that need it are defined as a group, the address is assigned to this group, and only one packet is sent to the address. The problem of the unicast method according to transmission, that is, the inefficiency of network resource utilization and the energy depletion problem of the receiving terminal due to excessive packets can be avoided.

However, as described above, there is a problem in that a separate protocol is required in order to enable efficient transmission by tracking and understanding who is the transceiver and where it is currently connected.

Two problems arise when applying the Internet Group Management Protocol (IGMP), a currently standardized group management protocol, to applications where multiple sources of information provide information to multiple recipients.

The first is the problem of delay in participation. In the case of IGMP, it is not possible to know in advance where the user will be connected, so each router periodically checks whether there are users in the area to which they are connecting and who they want to join. If you shorten the check period, the status of the group can be known more accurately. However, the communication for the check causes a heavy burden on the network and cannot be made too short.

Therefore, the current standard defaults to 120 seconds. Therefore, if you want to join a new multicast group or move from another network and continue joining a previously joined multicast group in the new network, it takes an average of 60 seconds for the router to know this. If the participation delay is long, the quality of the application service is degraded because the multicast-based application cannot receive the necessary information in a timely manner.

The second problem with applying IGMP-based multicast to ubiquitous computing environments is the group management burden.

In a ubiquitous computing environment, a large variety of information sources deliver information to different groups of users, resulting in a large number of groups. As the number of groups increases, each group should be checked and managed separately to see if there are any participants in the current network. This process is a burden on both the router side and the user terminal.

As the number of groups increases on the router side, there is a burden to maintain as many states, and the user's terminal needs to inform the router in order to maintain its subscription state for each group. Use a workaround to avoid telling about things. However, in order to avoid such duplication, it is necessary to confirm all the responses of other users, which causes a problem that the user terminal consumes a lot of power for communication. In addition, in a ubiquitous computing environment, a user's terminal frequently moves between different sub-networks, which causes a change in repetitive group configuration, which becomes more burdensome.

In the case of broadcast technology, since all user terminals receive an application that is needed after receiving a reception, there is a disadvantage in that it consumes power of the user terminal because it receives even unnecessary packets.

A further fatal drawback is that broadcast traffic is not transmitted beyond the link area to prevent excessive network traffic. Therefore, since the terminal to be received and the source of information to be transmitted belong to the same link, they cannot be generally applied.

The present invention is to provide a novel communication structure that can solve the problem of participation delay and management burden that occurs when the multicast technology based on the Internet group management protocol is applied to the ubiquitous computing environment.

That is, the present invention is to provide a novel communication structure that allows a plurality of users in a ubiquitous computing environment to smoothly receive information from a plurality of information sources.

The present invention relates to a communication system used for ubiquitous computing and a communication method using the communication system.

The novel communication scheme proposed in the present invention is intended to be called 'tunecast' to distinguish it from unicast, multicast, and broadcast, which are conventional communication schemes.

The 'tunecast' communication method of the present invention always keeps subscribed to all addresses assigned for tunecast and selectively receives only the data of a desired group, thereby delaying the participation delay and management, which is a problem of the prior art. Will resolve all.

The novel 'communication system' proposed in the present invention

A network unit configured to divide a portion of a multicast address block in a management area among the multicast address areas by dividing the block, and set the network to transmit data without separate group management for all data received through the designated address area; And

Comprising a list of the address of the group to receive the data, and when the data is received, including the receiving terminal for comparing the group address of the received data with the address list of the group to receive the data to determine whether to receive the data; do.

More specifically, the communication system of the present invention

The receiving terminal includes a physical layer, a medium access control (MAC) layer and an application layer,

Record the address of the group to be received in the medium access control (MAC) layer of the receiving terminal,

When data is received, the group address of the received data is compared with the list of group addresses recorded in the MAC layer of the receiving terminal, and the data only if the group address of the received data is in the group address list of the MAC layer of the receiving terminal. To the application layer.

The present invention also proposes a communication method using the novel communication system, which method is as follows.

Dividing and specifying a part of the multicast address list in the management area among the multicast address areas, and setting the network so that all routers are always subscribed to the designated address area.

Setting an address list of a group to receive data in a MAC layer of a receiving terminal;

Splitting and receiving all data sent through the designated address area,

Comparing the group address of the received data with the group address list recorded in the MAC layer of the receiving terminal;

And receiving the data only when the group address of the received data is in the group address list recorded in the receiving terminal and delivering the data to the application layer.

The communication method using the communication system of the present invention is as shown in FIG.

Hereinafter, the communication system of the present invention will be described in detail.

The 'tunecast' communication system of the present invention is largely composed of a network transmission method part and a selective reception method part in a terminal.

The network transmission method part is responsible for transmitting the traffic (that is, tunecast traffic) that conforms to the communication structure proposed by the present invention to all networks that require it.

Each router connecting a network of the present invention always maintains a subscription state for all groups corresponding to a specific address area to be received.

In this way, since each router always maintains a subscription state, each router transfers all data transmitted through a specific address range without any group management.

In the second part, the selective reception part of the terminal does not receive all the data reaching the user's terminal from the information source via each router, but selectively receives only the data of the desired group by viewing the group address of the received data. To pass on.

That is, the present invention allocates a separate tunecast-only group address area to all users connected to all sub-networks belonging to the predefined area so that it can be delivered immediately without delay of joining or canceling a group or burden of group management. With regard to the address area, all routers in the management area always remain subscribed without performing group management separately, thereby achieving the effect of the present invention.

Hereinafter, each configuration of the 'tunecast' communication method of the present invention will be described in detail.

Address area allocation for communication system of the present invention

Conventional communication schemes have different transmission characteristics and assign different address regions to easily implement these different characteristics.

Similarly, the communication system of the present invention can allocate and distinguish address areas so as to be distinguished from existing communication methods.

However, instead of changing the existing address allocation scheme, it is preferable to use a part of another area in terms of utilization.

To this end, the present invention divides and uses a part of an administratively scoped multicast address block in a management area which is a part of a multicast address area.

In this case, since the divided address area is an address derived from a multicast address block in the management area, data transmitted to this address is not transmitted outside the management area (for example, one institution).

However, in a ubiquitous computing environment, since most of the traffic (traffic) is meaningless beyond the management area (e.g., washing machine conditions in other homes) or is not desired for privacy reasons, this is not an obstacle in the present invention. Rather, it is a desirable feature.

Network sub settings

If a designated address area (hereinafter, referred to as a 'specific address area') is defined by dividing it from a multicast address block in a management area to be used for the communication system of the present invention, the network is configured to transmit data without separate group management in the network. .

Setting method can be implemented in two ways as follows.

First, the built-in IGMP function implemented in each router does not use the group management function defined in the IGMP standard for a specific address area, but instead always keeps it subscribed.

This can be implemented by modifying the software mounted in the router, which can be easily accomplished by those skilled in the art, and thus will be omitted in the specification of the present invention. The modification of this software does not affect the operation of conventional unicast, multicast, broadcast, IGMP, etc.

FIG. 2 is a simplified representation of all routers in the management area configured in advance to transmit information without the explicit participation procedure of the recipients in order to immediately transmit information to all the recipients in the management area.

Here, the number attached to each solid line indicates the network interface number of the router. Within the management area are three routers A, B, and C, which send to all other network interfaces for the group address g. At this time, the network interface receiving the data is excluded from the transmission target.

On the other hand, in this technique, since the area of transmission is limited to the management area, the network interface 1 is excluded from the transmission in case of router A.

Secondly, the communication system function of the present invention is applied only to a wireless access point.

In this case, no modification is made to the router at all, and instead, the wireless access point used for wireless access by each user's terminal is always maintained in a particular group address area.

In this case, since there is no function for the router to recognize a specific address range separately, the IGMP protocol will determine whether the user is subscribed. Therefore, the terminal eliminates IGMP traffic for a specific address region from the access point by snooping or responds to the access point itself so that the terminal is not burdened with group management.

3 illustrates an example of applying the technique of the present invention only in a wireless section without cooperation of a router. Herein, the access point automatically participates in that the original user terminal W should process the participation. The corresponding router is processed using the existing group management protocol.

Send through specific address range

When the information source wants to distribute the information through a specific address area, one group address is assigned and the information is transmitted as the target address. Since the same method as that used in the conventional multicast can be used, it is not described separately in the specification of the present invention.

Selective reception preparation on the receiving terminal side

In the present invention, the receiver who wants to receive the data transmits the address of the group he or she is trying to receive to the network protocol stack in his equipment through the network programming interface. For example, this process can use the setsockopt function on the socket interface.

At this time, the MAC (medium access control) layer included in the second layer in the network protocol stack knows the group address to receive, and records it. This process is the same as the process for conventional multicast reception.

Selective reception on the receiver side

In the present invention, when data is delivered to the receiver's terminal, the MAC layer compares the target address with a list of group addresses currently recorded. If it is on the list, it receives the data and delivers it to the application layer. Otherwise, the process is stopped and discarded.

4 is a simplified illustration of selective reception of a transmitted packet. The application in the user terminal suggests in advance which group to receive the information through the programming interface, which descends along the protocol stack to recognize and record in the MAC (medium access control) layer. Thereafter, the MAC layer checks whether it is a recorded group address with respect to the received data, discards it if it is not applicable, and delivers it to the upper layer (application layer) through the protocol stack if the address is previously recorded.

In this way, the receiver terminal can specify the address of the group to be received by the application to deliver only the necessary traffic to the upper layer can reduce the energy consumption of the receiver terminal.

The communication system proposed in the present invention has a large number of information sources within a limited range and enables communication without burden of participation delay or group management when a plurality of users share and receive this information.

Since there is no participation delay, even if a user carries a wireless terminal and moves between different sub-networks, the quality of service is improved by continuously receiving necessary information from an information source. In addition, since there is no burden of group management to continue receiving, the user's terminal can save energy to be consumed for group management.

On the other hand, by allowing the receiver terminal to specify the address of the group to be received by the application, unlike the broadcast, only necessary traffic is delivered to the upper layer, thereby reducing the energy consumption of the receiver terminal. On the other hand, even in unicast comparison, since there is little redundant traffic, energy consumption of the terminal can be reduced.

Such a communication method may be used as a basic information supply technique in a ubiquitous computing environment that will be widely used in daily life in the future.

Claims (6)

A network unit configured to divide a portion of a multicast address block in a management area among the multicast address areas by dividing the block, and set the network to transmit data without separate group management for all data received through the designated address area; And Making a list with the address of the group to receive the data, when the data is received, the receiving terminal to compare the group address of the received data and the address list of the group to receive the data to determine whether to receive the data Communication system comprising a. 2. The system according to claim 1, wherein the software mounted in the router is modified so that all routers in the management area remain subscribed at all times without using the group management function in the designated address area. Communication system in which network part is set to transmit data without separate group management. The communication system according to claim 1, wherein the network unit is set so that the wireless access point is always recognized as subscribed to the group address to which data is to be received. The communication system according to claim 3, wherein the network unit is configured to snoop to remove IGMP traffic for a group address to receive data, or to allow a wireless access point to respond to itself. The method of claim 1, Record the address of the group to be received in the medium access control (MAC) layer of the receiving terminal, When data is received, the group address of the received data is compared with the list of group addresses recorded in the MAC layer of the receiving terminal, and the data only if the group address of the received data is in the group address list of the MAC layer of the receiving terminal. A communication system that delivers to the application layer. Dividing and specifying a part of the multicast address list in the management area among the multicast address areas, and setting the network so that all routers are always subscribed to the designated address area. Setting an address list of a group to receive data in a MAC layer of a receiving terminal; Splitting and receiving all data sent through the designated address area, Comparing the group address of the received data with the group address list recorded in the MAC layer of the receiving terminal; And receiving the data only when the group address of the received data is in the group address list recorded in the receiving terminal and delivering the data to the application layer.

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