CNAP Specification and Validation: A Design Methodology Using LOTOS and UCM

Zhimei Yi

School of Graduate Studies and Research
in partial fulfillment of
the requirements for the degree of 
Master of Computer Science
Ottawa-Carleton Institute for Computer Science
Ottawa, Ontario, Canada
January 2000


Abstract

Over the past few years, the subject of Wireless Intelligent Network (WIN) has
captured the interest of the North American telecommunications community.  The
objective of WIN is to integrate Intelligent Network (IN) concepts into the
IS-41 architecture. The introduction of a Service Control Point (SCP) in the
Interim Standard IS-41 architecture enables independent specification of
services. By using the IN architecture, call processing intelligence and
feature functionality is separated from network switches. Subscribers can take
advantage of such IN services as call name presentation (CNAP) in a wireless
environment. 

In the first part of the thesis, we apply a scenario analysis technique to
capture the requirements of the CNAP system. The analysis includes building a
design model composed of User Case Maps (UCMs) and Message Sequence Charts
(MSCs). This technique helps in specifying the designed system at a high level,
brings us one step closer towards the specification of CNAP in LOTOS, and
contributes a method for generating test cases for further validation of the
specification. 

In the second part of the thesis, we validate the design of the CNAP feature
by constructing a LOTOS specification for it and validating the specification.
The formal specification of the CNAP service is based on the structure of
Network Entities (NEs) that are defined in the Network Reference Model (NRM).
The specification emphasizes the establishment of call connection and
processing of services in a wireless environment. 

It is concluded that UCMs, being an intuitive notation that can be used
loosely and at several levels of detail, is appropriate for the requirement
and service description in the development of standard.  LOTOS, being fairly
precise but being able to be used abstractly, is appropriate for prototyping
and validating the call procedures and services of WIN.