V.DELLAMEA
Being telemedicine a communication-based technology, and the Internet a cheap and widespread communication medium it is importan to understand the Telemedicine tasks that can be done in Internet
Internet can be defined as :
1.- An actitude about interconnecting and intercommunicationg without a single central owner entity
2.- Physical collection of routers and circuits anywhere in the world
3.- Connections using a standard common protocol:
IP ( Internet Protocol )
TCP ( Transmission control protocol )
4.- A set of shared resources ( level application layer )
STANDARDS : Apart from the common protocol ( at present moment do not guarantee QoS = Quality of service ) networking standards are not yet fixed.
The IP ( Internet Protocol ) allows the exchange of basic units called datagrams:
The data is place in a structure ( Internet Protocol packed )
Is addressed through a computer port ( Socket )
Towards an indentification number ( user / computer ):The ID is a 32 bits number ( 4 numbers separetad by dots and associated to a name )
The TCP ( Transmission control protocol ) : The exchange of datagrams
is done through an Application Protocol making a specific task
- Telnet ( Virtual terminal protocol ): log into a remote host
- e-mail (electronic mail):
Protocol:SMTP( simple mail transfer protocol )
Message format ( MIME )
- FTP ( file transfer protocol ): send and received files.
- Other : Gopher, Usernet news, mailing lists
Telemedicine applications in Internet :
1.- CSCW ( Computer supported cooperative work )
2.- Medical Data sharing ( multimedia workspace ) :WWW
Distributed information concurrently use by a group of users.Include WWW
In Telemedicine : CSCD Computer support cooperative diagnosis
May or may not include distributed computing in the following working schemes* Client/Server.
- Server acomplish the main task
- Client acts as user interface and preprocesses data for the server* Multiagents : Each agent accomplish specialized functions, being able to be a service provider as well as a client
WWW or World Wide Web : A wide-area hypermedia
information retrieval aiming to give universal access to a large
universe of documents.
Structure :
1.- Client/server protocol composed of two parts
Protocol of communications : HTTP = Hypertext transmission protocol
Hypermedia document definition: HTML = hypertext markup language
JAVA language compiler: javac
bit code interpreter : java
standard classes: AWT....2.- Common input and interaction with the server through
Forms
CGI ( Common gateway Interface ): standard interface between WWW and server side applications ( communication between HTTP server and other programs )
3.- Resources accesible with a single client : HTML documents, images through HTTP,FTP,Gopher ect..
Intelligent resource allocations : URL ( resource link )
PROBLEMS arrise when trying to introduce multimedia
communications , because TCP/IP networks are limited by the lack
of standards that guarantied QoS
New resources : Multicast BackBone ( MBONE ). An experimental
virtual network superimposed upor Internet using IP multicast,
which main application is videoconferencing
Part or total reproduction not allow without permission
Revisado: martes, 10 junio 1997.
Con el soporte informático y de comunicaciones
del CICEI, Universidad
de Las Palmas de Gran Canaria