Simulation of an Intelligent NetworkBasic Call State Model Szilárd CSEREY
What is an INTELLIGENT NETWORK ? • Intelligent Network – a separate and independent network that can be connected to a telecommunication network ( whether it‘s mobile or fixed ) in order to provide a large scale of services. • Intelligent Networks were created to enhance and to diversify the telecommunication services in fixed and mobile networks. • Services like: - toll free calls - prepaid calls - private numbering plans - call screening ( call filtering ) Siemens Program and System Engineering S.R.L.
Basic Call State Model • The Basic Call State Model is a Finite State Machine which describes the behavior of IN services in the call processing. • BCSM – an abstraction of a specific service Among the IN services we have implemented the “toll free service” just for a single number of 0800111 Siemens Program and System Engineering S.R.L.
The Basic Call State Model has two parts: Originating BCSM Terminating BCSM Siemens Program and System Engineering S.R.L.
Point-In-Call (PIC) and Detection-Point (DP) A BCSM finite state machine is described by the following components: - Point In Calls - Detection Points - Transitions - Events PICs represent a call processing state to the service logic, i.e. a running procedure in the basic call process. Detection Points are points between the PICs at which the call processing may be suspended in order to invoke actions of the service logic, i.e. ask for new instructions resp. data before the call processing continues or send a notification to the service logic. Siemens Program and System Engineering S.R.L.
The Intelligent Network simulator Developed in LabView 7 Student Edition Remotely accessible through the LabView embedded web server at: http://220.127.116.11:30700/in_bcsm.htm Every IN service is developed using a Service Creation Environment Service Creation Environments are applications which are used to create different types of services in a graphical manner, using grafical building blocks and putting them together to a create a specific service. Siemens Program and System Engineering S.R.L.
There are many proprietary applications on the market The scope is to visually build the services Graphical Flow Representation: Developers quickly and easily build services using drag-and-drop components, linking them in a visual flow-chart style representation to construct the call flow Siemens Program and System Engineering S.R.L.
Labview can also be used as a Service Creation Environment Labview has different grafical blocks that help to describe the behaviour of the Basic Call State Model, these are the : clusters, enumeration blocks, while loops, different types of connectors and so on. How to use the simulator, how to make a call ? There are two modes of user interraction: - One is where the user is just an observer - The other is when user interraction is needed, the user can make decisions regarding the treatment of the call Siemens Program and System Engineering S.R.L.
How to make a call ? An example of a regular call ( without the use of an IN service ) : In order to make a regular call without using specific IN numbers you have to use the prefix of “02” or “03” and 8 additional digits in order to have a correct and complete telephone number. A telephone number has to have 10 digits. If the prefix ( area code ) of the called number is correct ( 02 or 03 ) then the call is considered to be a call that doesn’t use IN services Siemens Program and System Engineering S.R.L.
How to make a call ? An example of IN call ( using the Free Phone service ) : The only service implemented in this simulator is the “Free Phone service”, and the toll free number that has to be called is 0800111 • If the destination number that has to be called has a prefix of 0800 then the • BCSM will analyze : • The day of the week • The time interval • The digits coming after the prefix Siemens Program and System Engineering S.R.L.
According to analyzed information it will make the corresponding decisions. The IN will route the call according to the following rules: - The call is routed to the closest telecom switch If it is Sunday the routing will be made automatically to the capital of the country, the called number has to be translated to 021080080 - If it is Saturday the routing will be made in terms of the callers prefix number to the closest regional telecom switch , translation will be made to the number <area code>0800800 - If it is one of the working days ( Monday to Friday ), the routing is done according to the callers prefix number and the time interval ( or time shift ) The called number will be translated to <area code>080080< the number representing the time shift 1 , 2 ,or 3 > Siemens Program and System Engineering S.R.L.