A UML DEFINITION OF A MANAGEMENT FRAMEWORK FOR

E-LEARNING SESSION-CENTRIC SERVICES

Theodore Apostolopoulos and Anna Kefala

Department of Informatics, Athens University of Economics and Business, 76 Patission str., 10434 Athens, Greece

Keywords:

e-Learning session-centric services, UML-deﬁned management framework, session proﬁle.

Abstract:

During the last decade, systems offering various e-learning services are implemented en masse. Proposed

management framework aims at acting as a facilitator among e-learning systems, learners, underlying commu-

nication infrastructure and access devices, content and delivery methods, forming an integration management

middleware, while at the same time acts as a broker for e-learning and content providing systems. Our frame-

work is session proﬁle centric, since a key characteristic is the dynamic creation of user session by detecting

and managing information and parameters that are either derived by stored proﬁles or change dynamically at

each user session. In this paper, we present content and e-learning provision services’ context, along with the

proposed architecture overview. We also present session proﬁle and a UML deﬁnition of its creation process.

1 INTRODUCTION

Since electronic services have emerged as the new

popular trend in service provision area, education

market has shifted towards electronic learning in a

view to offer alternative and ﬂexible services. Tech-

nology has offered consumers capability to acquire

access to e-services provision from anywhere. How-

ever, users are not always experienced in using elec-

tronic environments. Consequently, research focuses

on offering personalized services to users according

to their proﬁle, preferences or context. Designing

and implementing an e-learning service is a com-

plicated process, since there are many factors that

deﬁne the service. With a view to manage such a

service, we propose an e-learning services manage-

ment framework, which also offers brokerage services

to content/e-learning providers (Apostolopoulos and

Kefala, 2003b). A core element of the management

framework is the dynamic creation and management

of user session, according to diverse parameters and

information that are either static or change dynam-

ically per session. In sections 2 and 3, we present

context analysis and related work in the area of e-

learning/content services, along with an architectural

overview of proposed management framework. In

section 4, we analyse user session proﬁle and give a

formal description of session proﬁle creation using a

UML diagram.

2 CONTEXT REVIEW

Content Management Systems mainly focus on con-

tent creation, management, delivery and contracting

with customers (Robertson, 2002). Learning Content

Management Systems (LCMS) concentrate on man-

aging learning content at learning object granularity

(Wan et al., 2005). Learning Management Systems

are usually focusing on learner management, progress

tracking (Akpinar et al., 2004), facilitation of learner-

tutor interactions (Redol et al., 2003)and management

of administration issues. Learning Resource Brokers

usually implement functions, such as: browsing and

searching of resources, displaying metadata concern-

ing these resources and managing of resources deliv-

ery (Retalis et al., 2004). Consumers can now enjoy e-

content and e-learning services from home, connected

through narrowband technologies, from work, from a

university campus having broadband connectivity, or

while being on the road via some mobile network, de-

ploying diverse devices such as desktop computers or

523

Apostolopoulos T. and Kefala A. (2007).

A UML DEFINITION OF A MANAGEMENT FRAMEWORK FOR E-LEARNING SESSION-CENTRIC SERVICES.

In Proceedings of the Third International Conference on Web Information Systems and Technologies - Society, e-Business and e-Government /

e-Learning, pages 523-526

DOI: 10.5220/0001280405230526

 SciTePress

laptops, PDAs or cellular phones.

Context awareness is lately designated as a key pa-

rameter for adaptive e-services. In (Keidl and Kem-

per, 2004), they present a context framework that fa-

cilitates the development and deployment of context-

aware adaptable web services and they include con-

sumer’s identiﬁcation details, type of device, loca-

tion, communication and format as context elements.

In (Handorean et al., 2005), they introduce a con-

text aware ”follow-me sessions” management archi-

tecture within an ad hoc networking environment,

where a client is allowed to switch service provider

when needed.

As depicted in (Broens et al., 2004), the

”Cooltown” project allows users to discover services

that are in user’s vicinity and the ”Context Toolkit”

provides functionality to discover services using con-

textual information, allowing for the description of

services by means of white and yellows pages. In

the same paper, they present an approach for service

discovery that uses ontologies to capture the seman-

tics of user’s query, of services and contextual in-

formation that is considered relevant in the match-

ing process. In (Yang, 2006), they propose a context

aware ubiquitous learning environment consisting of

a peer-to-peer content access and adaptation system,

a personalized annotation management system and a

multimedia real-time group discussion system. Some

systems offer e-learning service adapted to students

learning style identiﬁed by their abilities, learning at-

titudes and preferred ways of study (Park, 2005), and

are based on a model which expresses goals, prefer-

ences, and knowledge of individual users (Lee and

Chong, 2002).

Most implemented content/e-learning provision

platforms are not ﬂexible enough to meet dynamically

altering context and connection characteristics, while

even the more sophisticated ones, usually support ei-

ther personalization of content according to user pro-

ﬁle, or emphasize user-service vicinity factor, but still

do not take into account all parameters that might dif-

ferentiate from session to session. Therefore, we have

noted the lack of a Content and e-Learning Provision

Services Management Framework that would manage

all diverse aspects of such services and would act as

a broker among content and e-learning providers and

users (Apostolopoulos and Kefala, 2003a).

3 ARCHITECTURAL OVERVIEW

Proposed e-Learning Services Management Architec-

ture is based on a middleware concept, considering an

intermediate layer between some e-learning providing

application and the underlying communication infras-

tructure (Apostolopoulos and Kefala, 2003b). Pro-

posed framework offers a management scheme for

e-learning services provision by gathering and man-

aging various information and metadata concerning

all involved stakeholders, systems and infrastructure.

In order to support architectural simplicity, ﬂexibil-

ity and adaptability, we have chosen a component

oriented design approach. Proposed e-learning ser-

vice management framework is based on a three-layer

architecture. The lower one concerns management

of network infrastructure, including communication

protocols, as well as management of access device

characteristics. The upper layer of proposed architec-

ture is occupied by some e-learning/content provid-

ing system. Depending on functionality supported by

these systems, middleware undertakes a more or less

active role, acting only as a broker or providing com-

plete management service. The intermediate layer

concerns the proposed management middleware.

While analyzing layered architecture, different

components are deﬁned, which deal with implement-

ing speciﬁc functionality. Each component manages

a set of information concerning offered services and

actors interacting with middleware. The main com-

ponent (Service Management Component) is the one

that dynamically creates and manages a session pro-

ﬁle, taking into account various parameters in order

to offer adequate quality of service (Apostolopoulos

and Kefala, 2004). These parameters are managed by

different components of the middleware in a view to

meet requirements for ﬂexibility and implementation

simplicity. This component undertakes the role of ser-

vice manager and is also responsible for coordinating

components’ interaction. Service Manager either cre-

ates a new user session or rejects user request in case

that service prerequisites are not satisﬁed. This com-

ponent manages all required information so that at any

given moment, an overall snapshot of system status

can be retrieved and formed (active sessions, service

availability, resources availability, number of served

users, etc.).

Since a key requirement is offering same kind of

services to users accessing broker services via diverse

devices and connection types, availability of differ-

ent content versions is an important issue. When,

for example, a user -using a low bandwidth and lim-

ited presentation capabilities mobile phone- requires

content, broker should select a version of the content

that would not be so fancy or resource demanding,

whereas to a user on a personal computer at a univer-

sity campus, broker could provide a different version

of the ”same” content that would be more resource-

consuming.

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524

4 SESSION PROFILE

Since learner might access service from different en-

vironments in terms of network connectivity and de-

vices, our management framework emphasizes on de-

tecting user’s current context characteristics in order

to decide on accepting user’s request and form spe-

ciﬁc session’s proﬁle. In order to create session pro-

ﬁle, not only current user environment parameters are

taken into account, but also current system’s network

conditions, availability of learning methods and com-

munication protocols, as well as service providers re-

sources availability and capacity.

Information that deﬁnes a session proﬁle, includes

data that are static and are derived from stored proﬁle

of system entities, as well as dynamic ones that might

vary per session and are gathered on real time terms.

Session proﬁle covers the following axes:

• User request parameters (dynamic). It comprises

user identiﬁcation parameters and requested ser-

vice identiﬁcation elements.

• Stored user proﬁle (static). It comprises informa-

tion concerning identiﬁcation elements, personal

information, regional and language settings, user

background, history of interactions with broker,

user preferences, security information and pay-

ment methods.

• User SLA (static/dynamic). User Service Level

Agreement (SLA) is some kind of a contract be-

tween user and broker, that deﬁnes the type and

level of provided services. SLA is related to Qual-

ity of Service (QoS), which contains various con-

straints and requirements, in terms of network

bandwidth and response time parameters, reliabil-

ity, availability and cost.

• User current context (dynamic). Information de-

scribing current user context and concern her cur-

rent location, time, access device capabilities,

type of network connection and its characteristics

and limitations.

• Brokerage and management service context (dy-

namic). This information mainly concerns bro-

ker resources availability and overall system sta-

tus. Communication network’s condition during

the time the request for connection is issued (net-

work load, available bandwidth, etc.) combined

with the potential load introduced by the new con-

nection is included.

• Service context (dynamic). Service context in-

cludes service proﬁle, networks and protocols for

service binding, devices and platforms for ser-

vice execution, availability and status of involved

providers.

4.1 Session Proﬁle Creation Using UML

Sequence Diagram

In the following paragraphs, we outline session pro-

ﬁle creation process, which is also depicted in Figure

1, as a UML sequence diagram. Presented sequence

diagram aims at capturing the behavior of system dur-

ing session creation phase. This diagram describes

interaction and collaboration between actors and sys-

tem components in terms of messages passed between

them in a sequential order.

As soon as a new request for service arrives at

broker, several component agents are triggered in or-

der to manage and serve user. Request is initially ad-

ministered by the Security sub-Component, which is

responsible for deciding whether the user is a regis-

tered and authorized one. User passes through some

authentication procedure, depending on the security

policy implemented. As soon as a user is success-

fully authenticated, her request is further processed

to Service Management Component and more specif-

ically to Session Manager, while Learners Proﬁle

Management Agent retrieves learner’s stored proﬁle

along with user’s Service Contract information. Ses-

sion Manager is responsible for approving, initiating

and managing a new session in order to serve the re-

quest. In order to decide whether the new request is

served or rejected, it needs to concentrate all required

information either static or dynamic.

Network and device agents are activated in order

to detect current network status of user’s connection,

deployed network technology and access device char-

acteristics on one hand, network availability and load

of service providers on the other. Content Service

Provision Methods Management Agent is responsi-

ble for providing information related to the types and

methods of e-learning process currently available for

the speciﬁc user, according to her contract and cur-

rent status of e-learning service. At the same time,

Content Management Agent decides on the types of

learning content that can be provided to user accord-

ing to her current connectivity status and Service Con-

tract. In case that different versions of ”same” content

are available, appropriate version in order to provide

quality of service, is chosen. At that point, Session

Manager has gathered all necessary information to

decide whether user request can be served adequately,

according to user’s Service Contract or not. Deci-

sion is based on combining all available information.

In case that request can be adequately served, a ses-

sion with user is initiated by activating an agent man-

aging and monitoring speciﬁc session. Simultane-

ously, Logging-Accounting sub-Component triggers

accounting procedure.

A UML DEFINITION OF A MANAGEMENT FRAMEWORK FOR E-LEARNING SESSION-CENTRIC SERVICES

525

Figure 1: Session Proﬁle Creation.

5 CONCLUSION

The proposed management framework presents a bro-

kerage scheme for diverse content and e-learning pro-

viding systems, offering a common interface and ser-

vice management context to users. The management

framework is designed on a session-centric approach.

Session proﬁle is created dynamically, taking into ac-

count several parameters and context information -

either static or dynamic- that might vary from session

to session, in a view to ensure quality of service for

users. Proposed framework can be deployed not only

within e-content and e-learning service domain, but

within e-services provision market in general.

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