Mobile Agentbased Service Configuration

MAT allows for object migration and supports Virtual Home Environment (VHE) in the Universal Mobile Telecommunications System (UMTS). VHE uses MAs in service subscription and configuration.

UMTS supports QoS, the Personal Communication Support (PCS), and VHE. The VHE allows for service mobility and roaming for the user, which carries subscribed and customized services while roaming. During the registration procedure, the VHE enables the visited network to obtain the information about the user's service provider, the user's personalized service profile, and the identification about service capabilities to execute specific services.

The VHE architecture shown in Figure 2.11 can be viewed as middleware layer that hides from the user the concrete network capabilities and differences in user and provider system capabilities. Service intelligence can be located inside the network within the Service Control and Mobility Management Platform (SC & MMP) or outside the network within the Universal Service Identification Module (USIM) of the end system. Service adaptation and media conversion is needed to cope with the diversity of end systems supporting personal mobility and QoS variations of different ANs supporting terminal

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End systems

Drovider systems

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Applications (subscribed services)

Virtual home environment

Transport networks

Figure 2.11 Virtual home environment.

Figure 2.11 Virtual home environment.

mobility. The enhancements of service control intelligence during service execution and dynamic subscription of a new third-party services should be allowed in the system.

The UMTS environment shown in Figure 2.12 consists of a terminal, the AN, the SC & MMP, and the third-party service provider. A user registers at the terminal that presents services to the user. The user's identification and authentication is handled by the UMTS Subscriber Identity Module (USIM). The network access of the terminal is managed by the access network. Fixed or mobile terminals are linked by the AN to the SC & MMP. The SC & MMP contains service logic and is responsible for the mobility management. Third-party service provides support supplementary services. A third-party service provider has a connection to one or more SC & MMPs and does not have its own mobility management facilities.

A middleware layer is introduced in UMTS architecture in Figure 2.13. The middleware consists of Distributed Agent Environment (DAE), for example, Grasshopper, which is built on the top of DPE, for example, CORBA, and spans all potential end user systems and provider systems. The nodes provide agent environments through middleware system

End user system Home provider system Other provider system Third party provider system

Figure 2.12 The main components of the third-generation mobile communication system.

End user system Home provider system Other provider system Third party provider system

Figure 2.12 The main components of the third-generation mobile communication system.

Visited MSC Gateway MSC Third party service provider

Figure 2.13 The distributed agent environment spanning across UMTS end user and provider systems.

Visited MSC Gateway MSC Third party service provider

Figure 2.13 The distributed agent environment spanning across UMTS end user and provider systems.

to enable downloading and migration of MAs. MAs contain intelligence related to mobility management and service control (VHE control) and the end user application between the involved system nodes, including the Mobile Stations (MSs).

In agent-based UMTS, a VHE-agent realizes the VHE concept; a Service Agent (SA) represents a provided service; a Terminal Agent (TA) allows the terminal to inform the provider system about its capabilities; and a Provider Agent (PA) realizes a trader within the provider system, which manages all supported services (SA), that is, maintains an overview of all available services within the provider domain.

The VHE allows individually subscribed and customized services to follow their associated users wherever they roam. The VHE-agent follows the user to the domain to which the user is roaming. At every domain, the VHE-agent provides the user's subscribed services and configurations.

Agencies in the MS allow dynamic distribution of mobility management and service control intelligence to be downloaded dynamically from the MS into the (visited) provider system and from the (visited) provider system onto the MS, to be distributed within one provider system at the most appropriate location and to be distributed between different provider systems. The end systems through the USIM can take an active part in mobility management and service control.

The PA residing in every provider domain contains the knowledge of all services provided by this domain. The PA is designed as a trader in MASIF. The PA is the initial contact point of the VHE-agent after the user is roamed to a new domain. The PA is designated as a stationary agent since its task makes the migration of this agent not necessary.

The SAs are located within the provider domain, or at the third-party service provider domains, or at the user's terminal. The Converter Agents (CAs) at the provider agency are responsible for converting incoming and outgoing calls on the basis of user and terminal requirements. This allows for support of services on terminals that cannot originally

present the service such as reading out a fax or e-mail on a telephone. The knowledge of the terminal capabilities is maintained by the TA. Different types of agents and their communication relationships are shown in Figure 2.14.

The VHE-agent can migrate from the provider domain from which the user comes to the provider domain to which the user is roaming. Another possibility is to store a major copy of the VHE-agent within the home service provider domain. Whenever the user roams to a new provider domain, a copy of the VHE-agent migrates to this domain. The VHE-agent can also be stored on the terminal agency. The VHE-agent migrates from the terminal agency to the provider agency when the user roams to a new domain.

Dynamic subscription allows a user to subscribe to and to unsubscribe services. The subscription component presents the entire set of provided services to the user. The information can be retrieved during the registration procedure after the user roamed to a new provider, and the subscription component requests the provider to get information about provided services. The services of a new provider can also be concatenated to the service list that is stored by the VHE. The network can provide a roaming broker that can be contacted by the subscription component to get the information about service providers.

The abstract service subscription is present at the provider where the user roams. The user registers at the new provider, and the VHE-agent contacts the PA to receive a subscription interface to process the VHE request. The PA finds an SA that corresponds to the abstract service description. The PA returns a reference to the existing SA that matches with the service description. If there is no SA matching service description, the PA finds a corresponding agent at different service providers. The PA explores possibilities illustrated in Figure 2.15. The current service provider can contact other service providers, or a roaming broker can be used, or the home service provider can provide a reference to the service agent.

The User Interface Agent (UIA) is responsible for the presentation of the SA at the user's terminal. The UIA provides terminal-dependent service presentation capabilities. The same service can be represented by many UIAs for terminals with different capabilities. The VHE-agent decides which UIA download to the terminal as shown in Figure 2.16. The VHE-agent contacts the TA, which resides on the terminal agency, that

USIM agency U-

USIM agency Mobile station r

Figure 2.15 Service access strategies.

USIM agency U-

USIM agency Mobile station r

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1 MSC agency ^

1 - Provider agent tries to find a service agent in its own domain and with capabilities that can be presented at the terminal of the user

2 - Provider agent contacts the Roaming Broker (RB). The RB tries to find a matching service agent

3 - Provider agent contacts the home service provider to get access to the service agent

Figure 2.15 Service access strategies.

Service provider region

1- VHE-agent requests the Terminal Agent to get properties of the terminal. This information will be sent by the TA to the VHE-agent.

2 - The VHE-agent will request the provider agent.

3 - To find a corresponding UIA.

4 - If a UIA was found, it will be downloaded to the terminal agency.

Figure 2.16 The UIA selection procedure.

is, mobile station. This TA is device dependent and contains technical information about the terminal. The VHE-agent requests the TA to get this information. The returned values are used by the VHE-agent to find a corresponding UIA. The service subscription procedure is used to locate the UIA.

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