Service Composition for End-Users: a tool for ...

Service Composition for End-Users: a tool for Telephony Services Mazen Malek Shiaa1, Jens Einar Vaskinn1, Richard T. Sanders2 1

Gintel AS, NO-7465 Trondheim, Norway

2

SINTEF ICT, NO-7465 Trondheim, Norway

ABSTRACT In the Service Oriented Architecture paradigm services are self-contained software units. Several services can be composed into a composite service in a process called Service Composition. The research project UbiCompForAll (http://ubicompforall.org/) is about providing support and tools to end users so they can easily compose services. One of these tools is EasyComposer made by Gintel. EasyComposer is a graphical composition tool that makes it easy for end-users to compose telephony and messaging services. It presents a set of basic services which allows end-users to tailor composite telephony services to their individual needs. The tool chain supports execution of the service compositions in a service platform of a telecom operator network. The EasyComposer is a simple composition tool to handle primarily the end-user's incoming calls. Individual services include incoming call handling, time management, sending short messaging, call queuing, call forwarding, customized announcements, called-party hunting models, etc. EasyComposer is a downscaled version of a more advanced tool currently used by service developers at telecom operators. Both tools generate xml representations for execution in a live telecom platform. There are three basic steps to be performed by the user of EasyComposer in order to implement a new or modify an existing service composition: 1. Design: use the tool to define the service logic, using a pallet of standard building blocks 2. Deploy: use the deployment functionality to instantly install on an execution platform 3. Test: test that the design behaves according to the requirements by invoking real traffic. Figure 1 below shows snapshoot of the tool and an example composition. In this example the user has composed a service that achieves the following: -

Incoming calls to the user’s phone number are checked against a time management service (TimeManager) Based on two choices (Choice) the call is either sent to a FollowMe service (hunt a list of numbers owned by the user) or handled in another manner, for instance when it is late in the evening Calls based on the calling party number will be checked against a list of preferred list of numbers (VIP list) and then will be prompted certain choices (by pressing a digit) Calls can then be connected directly (Connect), transferred to the voicemail service (Voicemail), transferred to another number (Transfer), or disconnected (Disconnect), while the callee will receive an SMS indicating the calling party number (SendSMS).

Figure 1: Service composition using EasyComposer: handling of an incoming call

Service execution starts from a dedicated start module (Incoming Call in the figure above). Each module is then executed sequentially. The outcome of the execution of the current module will determine which module to execute next by following one of the edges (or otherwise terminate the execution). The strategy defines all possible execution paths through the service logic. For call handling services the service strategy defines an abstract call flow, outlining the potential execution of call handling operations of the service. The demo at ICIN 2010 will demonstrate service composition, allowing the conference participants to tailor their own telephony services. A live demo will be provided, where actual service compositions are developed live and demonstrated to the audience.