This document proposes a mobile service architecture to improve availability and continuity of services. It aims to enable discovery and consumption of equivalent services across different networks and technologies. The key components are a generic service interface, continuity agent, service discovery agent, and profile agent on the user's device, along with a continuity server, service infobase registry, and event service in the network system. The architecture allows seamless switching between services like phone and VoIP to maintain ongoing access based on location, user preferences, and service availability. An implementation switches between native and VoIP calling applications on a device.

1. A Mobile Service
Architecture for Improving
Availability and Continuity
Author: Nor Shahniza Kamal Bashah
Ivar Jørstad
Do van Thuan
Tore Jønvik
Do van Thanh
Presenter: SOK, Phearin
MBC Laboratory
Konkuk University

2. Content
 Introduction
 Motivation
 Related Works
 Enhancing Availability and Providing Continuity
 Implementation
 Conclusion

3. Introduction

4. Introduction
 In modern mobile environment, services
offered by various network systems are usually
NOT standardized.
 Example: GSM voice service vs. IP Telephony
 A new mobile service architecture - enables
the discovery and consumption of equivalent
services.

5. Motivation

6. Handling of equivalent
services
 A service can be implemented using different
architectures and technologies.
 Example:
 Data service -> 3G or WiFi
 Voice Service -> GSM or IP Telephony (chIPhone)
 Availability, ease of use, seamless
performance, security, price… motivate the use
of detection and swapping to the use of pop-up
service

7. Providing location-based
services
 When travelling, the mobile user will want to
have access to the same service.
 Example:
 Taxi service in Trondheim, London, China, Cambodia
=> there should be a taxi service switch
 To user, it is valuable to seamlessly access
the right service based on location.

8. Offering personalized service
 User preferences and personal data should
be remembered and dynamically re-applied
to every equivalent service at one place.

9. Related Works

10. Service continuity works at
NTNU
 Several works on service continuity have been
proposed.
 “Seamless service continuity is the …, where service
abruptness is bounded by the time it takes the user to move
between the two locations.”
 “Non-seamless service continuity is the …, but where
additional disruption is introduced due to a required
reorganization of the service composition.”
 No real implementation or usage has been achieved.

11. TISPAN (Telecoms & Internet
Converged Services & Protocols for
Advanced Networks)
 Service continuity is the ability for a user to maintain an
ongoing service during mobility.
 The definition may imply continuity across different
devices, but it is not clearly stated.

12. 3GPP Voice Call Continuity (VCC) and
GSMA VoLTE
 All works focus on seamless switching
between circuit switched voice and IMS
voice, well defined by mobile operators.
 The proposed work extends service continuity
over non-standardized services.

13. IEEE Media Independent
Handover (MIH)
 802.21 Media Independent Handover (MIH)
services support detection of mobile
communication channels of a mobile terminal in
the vicinity.
 Same service is implemented across all
heterogeneous networks
 The paper work supports service continuity offered by
different types of networks implementation and using
different components.

14. Enhancing Availability and
Providing Continuity

15. Clarification of the Service
Concept
 The paper is adopted from [9]: “A service is a
mechanism enabling the end-user’s access to
one or more capabilities”

16. Clarification of the Service
Concept
 A server on the network - hardware and
software - distributed over multiple network
elements
 A client:
 Generic client, eg. the Web browser, capable to
collaborate with any service server
 Specific/dedicated client collaborate only with
some specific service servers
 The paper focus on dedicated clients and the
way to provide service continuity on these clients

17. A Service Continuity
Architecture
 There is NO mechanism for switching the two
different services seamlessly and smoothly.

18. A Service Continuity
Architecture
 User’s Device
Generic Service: receives commands from the
user and to generate output, and invokes the right
service according to the availability.
Continuity Agent: performs the necessary
initialization and configuration for the replacing
service to continue from the point of the previous
service stop - capable of downloading, installing
and initiating the new service.

19. A Service Continuity
Architecture
 Service Discovery Agent: performs the dynamic
discovery of available services.
 Profile Agent: stores and administers the user
profile, provides an interface allowing the
Continuity Agent to fetch the necessary data for
service configuration and changes done by the
user when using the services.

20. A Service Continuity
Architecture
 Network System
 Continuity Server: carry out seamless transfer of
synchronous services like telephony.
 Service Infobase: a service registry containing
information of all services available and equivalent
at a location, providing open interface for service
registration and matchmaking
 Also provides Event service for notifications reception of
the subscribed Service Discovery Agent.

22.  Sequence Processes of
a Service Continuity
Architecture

23. Implementation

24. Implementation
 Continuity Server is realized by the Voice
server inherited from the EUREKA Mobicome
project [11]
 Service Infobase has been successfully
implemented in [12]

25. Switch between the native
Phone application and
chIPhone, a SIP client.
communicate with the
native Contacts to
provide proper
configuration and
contacts for Phone and
chIPhone

26. Conclusion

27. Conclusion
 The proposed service architecture dynamically
discovers and switches equivalent services by
ensuring the reusability of the user’s preference
and data, and controlling by the user.
 In addition to the service availability, handover
criteria such as QoS, security, price, etc will be
considered to be further work.

28. Thank You