KR100786389B1 - Adaptation qos middleware system and method supporting service in adaptation qos middleware system - Google Patents

Abstract

An adaptive QoS(Quality of Service) middleware system and a service supporting method in the system are provided to realize adaptive QoS middleware to support multimedia applications in ubiquitous environment, thereby adaptively ensuring QoS by considering a user's mobility as more effectively expressing/processing a lot of context information around the user. A context service module(110) collects contexts from various sensors(10) to analyze the contexts, notifies random applications(20) of the analyzed results, and confirms a user's mobility through the analyzed results. A QoS management service module(120) sets new QoS setup information using information of a host used by the user and initial QoS setup information, and executes QoS for the current session. A user mobility service module(140) receives information on the user's mobility, perceives the information of the host to which the user moves to send the perceived information to the service module(120), and performs session handoff with a client of the host. A multimedia service application interface module(150) receives context changes and controlled QoS information and session information to notify the applications(20) of the received information.

Description

ADAPTATION QoS MIDDLEWARE SYSTEM AND METHOD SUPPORTING SERVICE IN ADAPTATION QoS MIDDLEWARE SYSTEM}

1 is a block diagram illustrating a middleware structure according to embodiments of the present invention;

2 is a block diagram showing the structure of a JINI based middleware system according to a first embodiment of the present invention;

3 is a state diagram illustrating a screen of a system capable of inputting & querying user context information according to a first embodiment of the present invention;

4 is a flowchart illustrating a method for supporting a multimedia service in a middleware system according to a first embodiment of the present invention.

5 is a block diagram illustrating a concept of a context service module in middleware according to embodiments of the present invention;

6 is a block diagram illustrating a concept of a quality of service (QoS) management service in middleware according to embodiments of the present invention;

7 is a block diagram illustrating a concept of a service quality renegotiation in a service quality management service in middleware according to embodiments of the present invention;

8 is a flowchart illustrating a quality of service (QoS) management service procedure according to movement of a user in a middleware system according to a first embodiment of the present invention;

9 is a block diagram showing the structure of a genie based middleware system according to a second embodiment of the present invention;

10 is a flowchart illustrating a hard session handoff process according to a second embodiment of the present invention;

11 is a flowchart illustrating a soft session handoff procedure according to the second embodiment of the present invention.

The present invention relates to middleware design, and more particularly, to a middleware system designed as an adaptive quality of service middleware for supporting a multimedia application in a ubiquitous environment, and a method for supporting a multimedia service in the system.

Recently, many technologies for home networks in the ubiquitous environment have been developed. The middleware is the software system that is central to constructing all these home networks.

Middleware is also used to connect devices that exchange control information or streaming multimedia contents, and to isolate applications for basic hardware and network components. Middleware can be used as a framework for application services such as remote control, security and remote meter reading of various home appliances such as home appliance control, home theater, information service, and VOD service.

Such home network middleware can be divided into middleware for information appliances control and middleware for information appliances multimedia. The middleware for controlling information appliances provides an environment in which users can control various devices connected to the home network similarly to those of existing users without acquiring knowledge, and provides a platform for developing and executing application services of various home networks. to provide.

However, in a ubiquitous environment, which is a combination of mobile computing devices and an information processing environment, a highly distributed computing platform has been developed due to a large number of terminal nodes and frequent phase changes of a network. In such a ubiquitous environment, the amount and type of terminal system or network resources may vary.

Therefore, adaptive service quality management is required to guarantee the service quality according to the variable system and network resource conditions in such a pervasive environment, and the design of the service quality middleware for the implementation of the ubiquitous application is required.

There is an existing middleware system RCSM, and comparing the characteristics of the other middleware systems, such as RCSM is shown in Table 1 below.

Middleware Base technology Application Context handling QoS Management Mobility support RCSM CORBA Ad-hoc communication application Various contexts none none Gaia CORBA-based Component Technology General purpose application: Provide application framework Various context handling: Context File System none none Aura Task movement technology Non-real-time applications System resources Non real-time QoS User Mobility: Using Task Manager (prism) Klara Agent technology QoS-Sensitive Applications User location information Two-level framework (Development, RunTime) User Mobility: Using Agent Mobiware CORBA Multimedia applications none QoS Negotiation and Adaptation Host Mobility: QoS Control Handoff Palol SOMA General purpose none QoS Adaptation Host Mobility: Using Agent

In Table 1, RCSM is a middleware proposed to facilitate the development and operation of applications requiring context awareness and spontaneous group communication, and the context and processing method are defined as CORBA interfaces. Compile to generate an adaptive container (hereinafter referred to as ADC). The ADC collects the context and passes it to the application, which can be dynamically created and deleted during execution.

Gaia is a middleware architecture for the development of mobile user-centric active space applications, providing services related to location, context, events, and repository. The active space is not merely a physical space, but an environment in which internal computers are organically organized to serve users intelligently. However, the RCSM and Gaia provide a unified interface for providing various contexts to CORBA based distributed object applications, but do not consider the service quality management or mobility support of multimedia data.

Aura proposed a structural framework for migrating tasks that are running when users move their workspaces. However, Aura uses only simple location information and considers only non-real time service quality.

Klara proposes a middleware framework for service quality awareness application in ubiquitous environment and supports user mobility using agent technology, but does not consider various contexts.

Mobieware and Palol proposed a framework for supporting host mobility rather than user mobility. However, the Mobieware adjusts the quality of service of the mobile host through handoff, and Palol adjusts the quality of service of the mobile host through quality of service routing and pass reset.

Accordingly, an object of the present invention is to provide an adaptive service quality middleware design and application method and system having a middleware framework that considers various context processing functions, a service quality management framework for multimedia applications, and a user mobility support function.

The adaptive quality of service middleware system of the present invention for achieving the above objects, collecting the context from a variety of sensors to analyze the context, inform the analysis results to any application for the multimedia service, and the analysis results A service quality management service that executes a service quality for a current session by setting a context service module for checking whether a user moves through the service service and setting new service quality setting information using initial service quality setting information and information of a host to which the user has moved. A module and information about the movement of the user from the context service module, grasps information of the host to which the user has moved, transmits the information to the service quality management service module, and transmits the information to the client of the host to which the user has moved. Session handoff Adaptive service quality middleware for supporting a multimedia service consisting of a user mobile service module for performing a service, and a multimedia service application interface module for receiving the context change and the adjusted quality of service information and session information and informing the application. do.

The adaptive quality of service system of the present invention for achieving the above objects is an adaptive quality of service middleware system for supporting a multimedia service, and manages the mobility, quality of service and the collected context of the user, Convert to application-level integration context, transfer the middleware service to adjust the quality of service in consideration of the mobility of the user, and the middleware service to collect the context from various sensors, download the proxy, use the proxy A middleware client unit which receives the integration context, service quality information and session information and delivers the information to an application for a multimedia service even when the user moves, and performs user registration according to a request of the middleware service unit, andThe middleware receives the information from the client unit a proxy for the user of the register, it characterized in that it comprises a look-up service unit for transmitting to the client middleware.

In addition, the service support method in the adaptive quality of service middleware system to achieve the above objects, collecting and analyzing the context from the various sensors, and informs the analysis results to any application for the multimedia service, and the analysis results Performing a context service for checking whether the user is moved through the service, setting service quality setting information using information of the host where the user is located, and executing service quality for the current session using the set service quality setting information. Performing a service quality management service, performing a session handoff with a client of a host to which the user has moved, receiving the context change, the adjusted quality of service information, and session information to notify the application Characterized by including the process do.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals have the same reference numerals as much as possible even if displayed on different drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The present invention supports mobility using various contextual information and resources in the computer for various services considering the user's mobility in the ubiquitous environment, and provides CMQ (Context_aware, Mobility-aware, QoS-aware) implements a middleware framework. In addition, the present invention is adaptive to apply Java and JINI technologies for ubiquitous multimedia services (eg, Video On Demand (hereinafter referred to as VOD)) according to the implemented middleware framework. A quality of service middleware system (hereinafter referred to as middleware system) is implemented. Such a middleware system can effectively express and process various context information around a user, support session handoff according to user's movement, and provide an application with an adaptive quality of service adjustment mechanism.

Middleware is software that makes distributed computing as easy as traditional single-system computing. It provides a means of connecting clients and servers, or enables communication between different protocols, system operating systems, databases, or programs distributed across a network. It is usually located between the operating system and the application.

1 is a diagram illustrating a middleware structure according to an embodiment of the present invention.

Referring to FIG. 1, the middleware 100 is located between the ubiquitous sensors 10 and the application 20, and collects and processes information sensed in real time in a real time to provide a seamless multimedia service to the application 20. To provide. The middleware 100 may include a context service module 110, a quality management service module 120, a communication service module 130, and a user mobility service. and a user-mobility service module 140, a multimedia service API module 150, and a virtual machine 160.

The context service module 110 performs a context service for processing various information and contexts collected from the sensors 10 according to a user's movement in a ubiquitous environment, and a detailed context service is described with reference to FIG. 3. It will be described later.

The service quality management service module 120 sets a framework for service quality management, performs a service quality management service of setting a framework by grasping user mobility and renegotiating service quality to change service quality setting information. do. A detailed description of the service quality management service will be described later with reference to FIG. 4.

The communication service module 130 is a module that processes communication with a client. The communication service module 130 transmits context service information, service quality management service information, and user mobility service information to the client. Perform off and send and receive related information.

The user mobility service module 140 may provide a service to a user without interruption by performing a service quality control handoff that supports job movement between computers around the user when the user moves, and the context service module 110. As an event indicating the mobility of the user from the user information is transmitted to the service quality management service module 120 about the client host to which the user moved.

The multimedia service application interface module 150 delivers a processed context in a form that the various applications 20 can use.

As described above, referring to the accompanying drawings for a middleware system according to embodiments of the present invention applying a middleware framework capable of delivering an adaptive service quality adjustment mechanism to an application in consideration of user mobility to support a multimedia service in an ubiquitous environment. It will be described in detail. Here, the middleware system will be described as an example of a Java Intelligent Network Infra-structure (JINI) based middleware system capable of distributed operation in a distributed network environment composed of various platforms, devices, and networks, but using other middleware frameworks. Note that it can also be applied to a distributed middleware system.

2 is a block diagram illustrating a structure of a JINI based middleware system according to a first embodiment of the present invention. The genie-based middleware system is a ubiquitous multimedia system (UMS), hereinafter referred to as a middleware system for convenience of description.

Referring to FIG. 2, the middleware system 200 may express and retrieve various context information of a user's state, location, identity, activity, etc. using a context model for a ubiquitous multimedia service. ) And middleware service unit 220 and lookup service unit 230.

The middleware client unit 210 includes an application interface unit 211 that interfaces with applications, a context monitor 212 for displaying a context collected from the sensors so that the user can monitor the user, and the user currently Quality of service monitor 213 for displaying the quality of service of the session in service for the user to monitor. The middleware client unit 210 may download the proxy from the lookup service unit 230 and use the same to obtain context information, service quality information, session information, and the like from the middleware service unit 220. Here, when the context monitor 212 or the service quality monitor 213 shows a screen of the middleware system for monitoring, it is as shown in FIG. 3.

The screen of the ubiquitous multimedia system includes, for example, a context view, an event view, and a message view, and the context view shows an event when a user's movement occurs. The event view shows an event when the user's movement has occurred, and the message view shows text messages sent and received like general online chat programs. On these screens, your context can be entered in the "Input My Context" panel, and the context of other users can be retrieved in the "Query Context" panel. 7 illustrates an example of a result of searching for the context of the user "hansol".

On the other hand, the middleware service unit 220 controls the handoff according to the movement of the user and the user movement management unit 221 for managing the user movement information, and set the quality of service in consideration of the mobility of the user, the service quality setting information Service quality management unit 222 for managing the context, the context management unit 223 for performing a context service for converting and managing the context collected from the sensor to the integrated context and the storage unit (DB) for managing all information related to the middleware service ( 224).

A method of supporting multimedia applications in the genie-based middleware system according to the first embodiment of the present invention configured as described above will be described. Specifically, CQM, that is, context service, QoS management service, and mobility (hand) OFF) operation for the service will be described in detail with reference to the accompanying drawings. If the middleware implemented as described above is applied to the genie-based middleware system, the context service function in the context service module 110 is performed by the context manager 223, and the service quality management service module 120 may be configured. The service quality management service function is performed by the service quality management unit 222. In addition, it should be noted that the mobility service function in the user mobility service module 140 is performed by the user mobility management unit 221.

4 is a flowchart illustrating a method for supporting a multimedia service in a middleware system according to a first embodiment of the present invention.

Referring to FIG. 4, in operation 400, the middleware system 200 sets a proxy for a registered user in association with a discovery 311 and a lookup service unit 230 for a multimedia application service. Download to 210). A process for this will be described in detail with reference to FIG. 2.

Both the client unit 210 and the middleware service unit 220 need a registration procedure, and register themselves with the lookup service unit 230 in step 311. Then, in step 312 and 313, the client unit 210 and the middleware service unit 220 is requested / approved by the lookup service unit 230. Here, the lookup service unit 230 may exist in plural. When the registration of the client unit 210 and the middleware service unit 220 is completed, the client unit 210 downloads the proxy of the middleware service unit 220 for the required service. Accordingly, in step 314, the client unit 210 communicates using the downloaded proxy information (RMI communication). As a result, the client unit 210 may receive a service provided by the middleware service unit 220.

Referring back to FIG. 4, in operation 410, the middleware system 200 sets initial service quality setting information (parameters) of an actual executable application level in consideration of system resources and network resources through the service quality management unit 222. Detailed description thereof will be described later with reference to FIG. 6.

In operation 420, the middleware system 200 transmits and receives relevant information (user, application, resource information, etc.) with the client unit 210 to perform a context service in the context manager 223.

In step 430, the middleware system 200 performs service quality renegotiation considering user mobility through the context service to adjust service quality setting information. In operation 440, the middleware system 200 transmits the service result information, that is, the integration context according to the adjusted service quality, to the client unit 210 from the context manager 223. This context service will be described in more detail with reference to FIG. 5.

5 is a block diagram illustrating a concept of a context service in middleware according to embodiments of the present invention.

Referring to FIG. 5, the context service module 110 performs a context service. The context service includes a context collector 511 for receiving a signal and a context detected from the sensors 10, and a context. The context may be divided into a context history process 512 for storing a context analysis context and a context parser process 513 for receiving and analyzing an integrated context. In addition, when the context service function of the context service module 110 is applied to the genie-based middleware system 200 illustrated in FIG. 2, it should be noted that the context management unit 223 is performed.

In the context collecting process 511, the context manager 223 generates a unified context by collecting a context, that is, a preliminary context, detected from the various types of sensors 10. Since the primitive context is sensor-dependent, it cannot be interpreted at the application level, so a transformation to an integrated context is required. Therefore, the context manager 232 is processed by the user movement manager 221 and the service quality manager 222 and converts the user movement information and the service quality information stored in the storage 224 into an integrated context. The converted unified context is stored in the storage unit 224 so that the context context for the converted unified context can be known in the context of the process 512.

Thereafter, the context manager 223 transmits / receives the query / result with the applications 20 in the context analyzer 513, that is, interprets the integration context, and transmits the result to the corresponding application 20. In addition, the integration context required by the specific application 20 is read from the storage unit 224 and output as a result value. In the context analysis process 513, the context manager 223 analyzes the unified context and generates an event at a timing requested by the application 20, thereby applying a change in context that may occur due to the movement of the user. Notify

Meanwhile, the service quality initial setting and the renegotiation service quality management service performed in steps 410 and 430 of FIG. 4 will be described in detail with reference to the accompanying drawings.

6 is a block diagram illustrating a concept of a quality of service (QoS) management service in middleware according to embodiments of the present invention.

Referring to FIG. 6, the framework for quality management of the quality management service module 120 includes an establishment phase 610, a provision phase 620, and a handoff phase. phase) 630 to operate.

The setting step 610 includes a quality of service specification process (QoS Specification) 611, a quality of service mapping process (QoS Mapping) 612, and a service quality negotiation process (QoS Negotiation) (613).

The quality of service specification process 611 is a process of specifying quality of service at a user level, an application level, and a resource level. This user-level service quality specification is necessary because user-centered service must be provided in an ubiquitous environment.

The service quality mapping process 612 is a process of mapping a user level service quality specification to an application level service quality parameter and a resource level service quality parameter.

The service quality negotiation process 613 is a process of setting a service quality parameter that is actually executable in consideration of system resources and network resources due to changes in environment and devices that may occur due to user's movement.

The preliminary step 620 is a step of executing service quality based on the service quality negotiated through the service quality negotiation 613. The resource monitor 621 and the service quality adaptation (or enforcement) process are performed. (QoS Adaptation) 622.

The resource monitoring process 621 monitors the changing situation of system resources and network resources and informs the user when the quality of service threshold is out of tolerance.

The service quality adaptation process 622 executes the negotiated service quality, performs service parameter setting, that is, service quality setting information obtained through service quality negotiation, and monitoring information received through the resource monitoring process 621. It is a process of renegotiating service quality by using and adaptively delivering setting information (service quality parameter) on the renegotiated service quality.

The handoff step 630 includes a context service process 631 and a handoff control process 632.

The context service process 631 is a process of sensing and interpreting the context collected from the sensor 10 according to the user's movement in the context service module 110, and delivering the user movement information to the application 20 in the form of an event. . The handoff control process 632 supports the movement of work between computers around the user through the results interpreted by the context service 631.

At this time, the service quality management service module performs a service quality management service that executes service quality in consideration of system resources and network resources according to changes in the environment and devices that may occur due to the movement of a user. The operation of the service quality management service module will be described in detail with reference to the accompanying drawings.

7 is a flowchart illustrating the operation of the service quality management service module according to the first embodiment of the present invention.

Referring to FIG. 7, in step 710, the service quality manager 222 performs initial service quality setting. That is, the service quality management unit 222 specifies the service quality in consideration of the user level, application level, and resource level, and maps the user level specification to the service level parameter of the application level and the service quality parameter of the resource level.

Then, in step 720, the service quality management unit 222 performs an initial service quality negotiation by setting a service quality parameter of an actually executable application level by reflecting system and network resources in the mapped service quality parameter. In operation 730, the service quality manager 222 executes the service quality based on the set service quality parameter, that is, the initial negotiation service quality in the preliminary step 610.

If the user moves, and the environment or device changes, it is necessary to change the negotiated quality of service. Therefore, in step 740, the service quality manager 222 checks whether there is a user movement (handoff). The user's movement is sensed through various sensors 10, through which the collected context is interpreted, and the user's movement information, which is an interpreted result, is transmitted to the application. In this case, the service quality manager 222 determines whether the handoff has occurred by checking the user movement information interpreted by the context manager 223.

As a result of checking in step 740, if a handoff occurs, in step 750, the service quality manager 222 performs a service quality control handoff. That is, the service quality management unit 222 supports the movement of work between computers around the user. On the other hand, if no handoff occurs, the process proceeds to step 730.

In operation 760, the service quality manager 222 performs a service quality renegotiation of resetting service quality parameters, that is, service quality setting information, based on the newly moved client host using the user movement information.

In step 770, the service quality manager 222 checks whether the current service quality setting information exceeds a preset threshold while performing the monitoring 124 through the resource monitor. As a result of the check, if the threshold value is exceeded, in step 780, the service quality management unit 222 adaptively adjusts the service quality parameter, that is, the service quality setting information, of the session in service using the monitoring information transmitted from the resource monitor. Proceed to step. On the other hand, if the threshold value is not exceeded, the process proceeds to step 790 as it is.

In step 790, the service quality management unit 222 executes a new service quality according to the service quality setting information set through the renegotiation which is the current setting information or the adaptively adjusted setting information.

As such, the quality of service management service enables the service quality control handoff to be provided to the moving user without interruption. In this case, the service quality renegotiation as in step 760 of FIG. 7 is accompanied, and this service quality renegotiation will be described in more detail.

8 is a block diagram illustrating a concept of service quality renegotiation in a service quality management service in middleware according to embodiments of the present invention.

Referring to FIG. 8, the service quality manager 222 performs a service quality renegotiation of resetting service quality parameters based on a newly moved client host through a service quality negotiation process 613. In this process, information on the current QoS setting (Q = (qfm, qfs, qfr)) can be used to determine the specification, capacity, user preference and In consideration of the throughput output according to the resource change in the resource monitoring process 622, new service quality setting information Q '= (qfm, qfs, qfr) is changed. In this case, the service quality setting information (Q, Q ') may be a video quality (qfm), a frame size (qfs), a frame rate (qfr), etc. as an application level quality of service parameter.

In the first embodiment of the present invention as described above, the genie-based middleware system is applied to the ubiquitous multimedia system, but in the second embodiment of the present invention, the genie-based middleware system is referred to as ubiquitous VOD (UVOD or less). It will be described by applying to the system.

Next, a structure of a genie-based middleware system to which a ubiquitous VOD (hereinafter referred to as UVOD) according to a second embodiment of the present invention is applied will be described in detail with reference to the accompanying drawings.

9 is a diagram illustrating the structure of a genie based middleware UVOD system according to a second embodiment of the present invention.

Referring to FIG. 9, the UVOD system is divided into a service unit 910, a transmission unit 920, a client unit 930, and a lookup service unit 940, and two (Jini and JMF). Has a communication interface. The Jini interfaces 1041 and 1042 are used for control information communication of the VOD system, and the JMF interface 1050 is used for transmission and playback of media data.

The service unit 910 is a Genie service that controls the VOD system. The service unit 910 manages a VOD session and supports user mobility, and a service manager 911 that controls a client unit 920 and a transmitter 930. A movement manager 912 for managing and controlling the movement of the user, and a sensor manager 913 for managing the sensors 10.

The transmission unit 920 performs a lookup to the lookup service unit 940 to receive the corresponding proxy, and the related information through the service unit 910 and the Genie interface (RM) 1041 using the received proxy. Send / receive The transmitter 920 may include a client manager 921 for transmitting a lookup to the lookup service unit 940, a VOD transmitter 922 for transmitting information for playing a VOD to the client unit 930, and a media. Media section 923 for storing the data.

The client unit 930 continuously displays a video to a user, and includes a client manager 931 that interworks with the lookup service unit 940, a location manager 932 that identifies a user's location, and a JMF / RTP interface ( And a VOD player 933 that receives the VOD information from the transmitter 920 and reproduces the VOD. Here, the client manager 931 receives a proxy from the lookup service unit 940 by performing a lookup for a CQM service to the lookup service unit 940, and uses the received proxy to provide a proxy. 910 and the Genie interface (RM) 1042 transmit and receive related information.

Next, an operation of a genie-based middleware system (hereinafter, referred to as a middleware system) according to the second embodiment of the present invention having such a structure will be described.

 The middleware system performs a registration process, a lookup process and a proxy download process like the middleware system according to the first embodiment of the present invention.

Referring back to FIG. 9, the service unit 910 of the middleware system performs a user discovery / join process 1010 in cooperation with the lookup service unit 940. At this time, the transmission unit 920 and the client unit 930 look up 1021 and 1031 to the lookup service unit 940, respectively, and the related information according to the movement of the user, and download the corresponding proxy, respectively (1032 and 1032). Then, the client managers 921 and 931 of the transmission unit 920 and the client unit 930 communicate with the service unit 911 and the Genie interface (RM) 1041 and 1042 using the received proxy, respectively. By performing the CQM service to support the multimedia application, the system control information and service related information are transmitted / received. Since the detailed CQM service procedure of this process is the same as the CQM service procedures in the above-described first embodiment, a detailed description thereof will be omitted.

 Then, when the CQM service is made, the VOD transmitter 922 of the transmission unit 920 receives media data for an application to be provided to the user from the media unit 923, and the client unit through the JMF / RTP interface 1050. The media data is sent to 930. Then, the client unit 930 plays the media data received through the VOD player 933 so that the user can view it.

If the user moves (handoffs) while receiving the media data, the service unit 910 manages the user mobility by using the living information of the surroundings and various resources in the computer, and considers the user mobility. It performs quality management service and context service to set quality. Then, the service unit 910 applies the set quality of service in consideration of the mobility, and then converts the initial context into the unified context, and transmits the converted unified context to the client manager 921 of the transmitter 920.

Then, the client manager 921 of the transmitter 920 receives the integration context, checks the mobility and adaptively controlled quality of service of the user, and performs session handoff to the host to which the user has moved. Accordingly, the VOD transmitter 922 transmits the media data to the VOD player 933 of the client unit 930 of the host to which the user has moved. Accordingly, the VOD player 933 can play the received media data to continuously show the application to the user.

An example of the execution of session handoff in the genie-based middleware UVOD system will be described with reference to the accompanying drawings.

Session handoff takes place in two ways: in the first, the user starts the VOD service on PC1 in the home domain, moves out of the home domain to the visited domain, and then back to the VOD through PC2. Continue to use the service.

Next, in the second method, the user starts the VOD service on PC1 of the home domain, leaves the MH with the MH, and uses the VOD service with the MH while moving. If the user enters the visiting domain, they continue to use the VOD service through PC2.

Users move between hosts in a pervasive space. Here, hosts that are currently available to the user are called candidate hosts, and hosts that currently provide the main service to the user are called primary hosts. If there are several candidate hosts, it is desirable to select a back protection host as the main host that can provide the best QoS to the user. The main host is determined through an evaluation function as shown in Equation 1 using the host specification vector (C), the resource utilization vector (U), and the user preference vector (W).

When a new main host is determined through this, handoff of the VOD session is performed. When a handoff occurs, the VOD service closes the session with the old main host and connects the new main host with the new session. At the application level, this process can be seen as a process in which a sub-session is released and newly created at the time of handoff.

Therefore, a hard session handoff and a soft session handoff process will be described based on the concept of the subsession.

10 is a flowchart illustrating a hard session handoff process according to the second embodiment of the present invention.

Hard session handoffs support this first approach, when the user 'moves out', closes the subsession with the old primary host and when the user 'moves in' to the new space, Create a new subsession.

Referring to FIG. 10, in operation 1101, the current client A 930a requests a service to the service unit 910, and in operation 1102, operates a main host from the service unit 910. Receive the command to turn on primary host. Thereafter, in operation 1103, the client unit 930a transmits a message for initiating a subsession to the transmission unit 920, and transmits a 'move out' message to the service unit 910 in step 1104 according to the movement of the user. Accordingly, in step 1105, a primary host off command is received. Thereafter, in operation 1106, the client unit 930a transmits a message (stop) for releasing the subsession to the transmission unit 920 to close the session with the current main host and attempt to connect with the new main host.

Therefore, when the user arrives, the new client unit 930b transmits a 'mone in' message to the service unit 910 in step 1107, and receives a command for operating the new primary host in step 1108. In step 1109, the new client unit 930b transmits a message for initiating a subsession to the transmitter 920. Accordingly, the transmitter 920 transmits the media. Thereafter, when the new client unit 930b transmits a message (close) to stop the service to the service unit 910, the service unit 910 sends the new client unit 930b and the transmission unit 920. Send a message to stop the subsession.

11 is a flowchart illustrating a soft session handoff process according to the second embodiment of the present invention. The soft handoff supports the second scheme, for example, when the user moves to the Visited domain with the MH, the candidate hosts are MH and PC2. Of these, PC2 is determined as the primary host, and a session handoff occurs between the MH and PC2. Such soft session handoff may provide seamless VOD services to mobile users. To do this, do not close the subsession of the old host until the new primary host attaches a new subsession.

)째 프레임까지 수신한 후 해제한다. 이후, 1207단계에서 서비스부(910)는 새로운 주 호스트를 동작(on)시키기 위한 메시지를 전송하고, 이를 수신한 새로운 클라이언트B(930b)는 전송부(920)로 서브 세션을 개시하기 위한 메시지를 전송하면, 새로운 서브세션이 연결되어 (#+

)번째 이후 프레임부터 버퍼링을 시작한다. 이때, 클라이언트A(930a)에서 (#+

)째 프레임을 재생한 직후, 1209단계에서 클라이언트A(930a)는 바로 서브세션을 닫고, 1211단계에서 새로운 클라이언트B(930b)는 새로운 서브세션의 재생을 시작한다. 이에 따라 상기 전송부(920)는 끊김 없이 미디어를 전송하게 된다. 이후, 1212단계에서 클라이언트B(930b)는 서비스를 중단하기 위한 메시지(close)를 서비스부(910)로 전송하면, 서비스부(910)는 서브 세션을 해제하는 메시지(stop)를 상기 클라이언트 B(930b) 및 전송부(920)로 전송한다. 여기서 핸드오프 지연동안 재생될 프레임들의 범위를 나타내는 오프셋(

)는 하기 <수학식 2>와 같이 계산될 수 있다.Referring to FIG. 11, steps 1201 to 1203 are the same as those shown in FIG. 10. When the subsession is started in step 1203, when the location of the user is changed, the user location is moved to the service unit 910 in step 1204. Send a location message containing the information. At this time, the VOD service unit 910 newly determines the primary host. Therefore, in operation 1205, the service unit 910 transmits a message for turning off the previous main host to the client A 930a. At this point, the client A 930a does not immediately release the subsession in step 1206 and starts with (# +) from the current frame (#).

After receiving up to the (th) frame, release it. In operation 1207, the service unit 910 transmits a message for operating the new primary host, and the new client B 930b receives the message for initiating a sub-session to the transmission unit 920. If you do, a new subsession will be connected (# +

The buffering starts from the ()) th frame. At this time, the client A (930a) (# +

Immediately after the second frame is played, the client A 930a immediately closes the subsession in step 1209, and the new client B 930b starts playing the new subsession in step 1211. Accordingly, the transmission unit 920 transmits the media without interruption. In operation 1212, if the client B 930b transmits a message for stopping the service to the service unit 910, the service unit 910 sends a message for releasing a sub session to the client B ( 930b) and the transmitter 920. Where an offset indicating the range of frames to be played during the handoff delay (

) May be calculated as in Equation 2 below.

는 평균 핸드오프 지연시간이고,

는 핸드오프 지연의 분산이다. 또한, F는 초당 전송되는 프레임율이고,

는 상수 값으로

=2를 사용한다. here

Is the average handoff delay,

Is the variance of the handoff delay. F is also the frame rate transmitted per second,

Is a constant value

Use = 2.

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

The present invention implements adaptive quality of service middleware to support multimedia applications in an ubiquitous environment, thereby adaptively guaranteeing the quality of service in consideration of the user's mobility, and more effectively expresses and processes various context information around the user. By doing so, it is possible to provide an optimal service to the user.

Claims (10)

A context service module that collects contexts from various sensors to analyze the context, informs the analysis result to any application for a multimedia service, and checks whether the user moves through the analysis result;  A service quality management service module configured to set initial service quality setting information and new service quality setting information using information of a host to which the user has moved, and to execute service quality for a current session; Receive information on the movement of the user from the context service module, grasp the information of the host moved by the user and transmit the information to the service quality management service module, and session handoff with the client of the host moved by the user A user move service module that performs  Adaptive quality of service middleware for supporting a multimedia service consisting of a multimedia service application interface module for receiving the context change and the adjusted quality of service information and session information to inform the application system. The method of claim 1, wherein the context service module, Collect the first context from the sensors, convert the first context into an application-level integration context, store the analysis, and analyze the integration context to generate an event at a timing required by the application to notify the analyzed result. Adaptive service quality middleware system. The method of claim 1, wherein the service quality management service module, It specifies user quality of service level mapped to application level and resource level quality of service setting information, and performs service quality negotiation to set the initial quality of service setting information of actual available application level based on the negotiated quality of service. An adaptive service quality middleware system characterized by executing an initial service quality. The service quality management service module according to claim 1 or 3, Adaptive service quality middleware system, characterized in that for controlling the quality of service of the session currently in service according to the monitoring result when the amount of change of system and network resources exceeds a predetermined threshold. A middleware service unit that manages a user's mobility, service quality and collected context, converts the collected context into an application-level integrated context, and adjusts a service quality in consideration of the user's mobility; Sends the context from the various sensors to the middleware service unit, downloads the proxy, and receives the integration context, service quality information, and session information even when the user moves using the proxy. Middleware client unit to deliver to the application for, And a lookup service unit configured to perform user registration according to a request of the middleware service unit, receive information from the middleware client unit, and transmit a proxy for the registered user to the middleware client. Adaptive Quality of Service Middleware System. Collecting and analyzing contexts from various sensors, informing the analyzed result to any application for a multimedia service, and performing a context service for checking whether a user moves through the analysis result; Setting service quality setting information using information of a host where the user is located, and performing a service quality management service for executing a service quality for a current session using the set service quality setting information; Performing a session handoff with a client of a host to which the user has moved;  And receiving the context change, the adjusted quality of service information and session information, and informing the application to the application. The method of claim 6, wherein the performing of the context service comprises: Collecting primitive contexts from the sensors, Converting and storing the initial context into an application level integration context; And analyzing the integration context to generate an event at a timing requested by the application and informing the analyzed result. The method of claim 6, wherein the performing of the service quality management service comprises: Specifying quality of service setting information (parameters) at the user level, Mapping the user level service quality setting information with application level and resource level service quality setting information; Performing service quality negotiation to set service quality setting information of an application level that is actually usable for the mapped user level service quality; And a method of executing an initial service quality based on the negotiated service quality. The method of claim 8, And setting new service quality setting information by using the information of the host to which the user has moved. The method according to claim 8 or 9, Adjusting the service quality of the session currently being serviced according to the monitoring result when the system and network resource variation exceeds a preset threshold, the service support in the adaptive quality of service middleware system Way.

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