Held, Gilbert  <br/><br/>
Understanding data communications/ 
Gilbert Held 
 - 3rd edition 
 - United State of America  sams a division of prentice  hall computer publishing   1988 
 - ix,368 P.  ill.;  24 cm. 
<br/><br/>                    The Content<br/><br/>Chapter <br/><br/>1. An overview of data communications<br/><br/>2 .Data terminals <br/><br/>3. Messages and transmission channels <br/><br/>4. Asynchronous modems interfaces<br/> <br/>5. Asynchronous modems and digital transmission<br/> <br/>6. Multiplexing <br/><br/>7. Fiber optic and satellite communications<br/><br/>8. Protocols and error control<br/> <br/>9. Alternatives in local area networks <br/><br/>10. Architectures and packet networks<br/><br/>11.Network design and management <br/><br/>12. ISDN<br/><br/> 
<br/><br/>Includes Index: p 351 - 365  
<br/><br/><label>ISBN: </label>0672300052 9780672300059 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Data communications
<br/><br/><label>Dewey Class. No.: </label>005.71  / HEL