Theodore Apostolopoulos and Anna Kefala
Department of Informatics, Athens University of Economics and Business, 76 Patission str., 10434 Athens, Greece
e-Learning session-centric services, UML-defined management framework, session profile.
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.
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.
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
Apostolopoulos T. and Kefala A. (2007).
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
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).
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-
WEBIST 2007 - International Conference on Web Information Systems and Technologies
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
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.
Figure 1: Session Profile Creation.
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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