(, OSI Open System Interconnection model) , ISO . OSI .
OSI , , . , .
OSI (.1.3).
. 1.3.
7- (Application): ; , . , , . , , , (mail-box).
6- (Presentation): (, , ). , EBCDIC (Extended Binary Coded Decimal Interchange Code ) ASCII (American Standards Committee for Information Interchange ) ..
5- (Session): , () . ( ), , .
4- (Transport): ; ( , ). (- ), , (, ). .
3- (Network): , , , . , . . ( ) , . . .
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2- (Link, ): , , , , . , . : (MAC Medium Access Control) (LLC Logical Link Control). LLC , . MAC .
1- (Physical): , , , ; . , , .
, . , () .
/ . , , , , . (), . (.. ). (.. ). .
2.1. :
(.. , ), . .
, . , , .
. , 1 = 10lg(P 1/ P 2), 1 2 .
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( ) . . () . , .. , , . .
( ) N , 2N. , 16 1200 4 / 4800 /.
V F - (, log2 k , k ):
V =log2 k / t, t , 3 , a =1/(2 F). k 1+ , /.
( ) . , . , . , . : ( , TDM Time Division Method), , (FDM Frequency Division Method), .
, .
() , () . , , - .
. , , - . , - .
, . ( 1/1, ISDN, Frame Relay, .).
( ), ( ) ( ).
- . , .
, , , ( ).
, , , .