Page 97 - Intelligent Communication Systems

80 INTELLIGENT COMMUNICATION SYSTEMS
8.1 CONCEPT OF INTELLIGENT COMMUNICATION
SYSTEMS

An intelligent communication system provides human-friendly telecommunication
services by applying intelligent processing. Examples of intelligent telecommuni-
cation services include: intelligent switching services, such as the intelligent phone
or one-touch dialing; intelligent directory service, such as the retrieval of a phone
number based on the subscriber's name or job category; and intelligent communi-
cation processing services, such as the interpreting telephone or media conversion.
The intelligent communication system is structured hierarchically, that is, in a lay-
ered structure. The functions of each layer are as follows:

• The physical layer includes the electrical and physical conditions of the
network.
• The data link layer includes the rules for communication between
neighboring nodes.
• The network layer describes the rules for communication between the
source node and the destination node.
• The transport layer includes the rules for communication between the
source process and the destination process.
• The session layer includes how to establish the communication link
between the source process and the destination process and how to
communicate (e.g., duplex communication or half-duplex communication).
• The presentation layer includes code conversion.
« The application layer includes the application functions provided to the
user.
In the intelligent communication system the intelligent processing layer is
defined as above the application layer. The user program is defined as above the
intelligent processing layer. The hierarchical structure of Intelligent Communica-
tion System is shown in Figure 8.1.

8.2 FUNCTIONS OF THE INTELLIGENT PROCESSING LAYER

The functions of the intelligent processing layer are performed by the following
systems:
• Knowledge-base system
• Natural language processing system
• Media conversion system
The knowledge-base system provides problem-solving facilities by using
knowledge in a knowledge base. The natural language processing system provides
interpreting facilities and language understanding. The media conversion system