ARQ N , , . , 1 , 2,3,,WS - 1 . , , - 1 2,3,,WS - 1. , .
ARQ (Selective Repeat, SR-ARQ) . :
, , , ;
, .. , .
.3.9 . . ; . .
, ( ), [ , ] NAK (Negative Acknowledgement), , , . . , , , . NAK, , , , , , ,, , , .
. 3.10 , WS =6 K0, K1,K5 . 3, 2, NAK ; K4, K5 . (NAK ), 2. , 2 , 3, 4, 5. .
, . Ÿ , GBN-ARQ, . , GBN, .. (. 3.11).
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, , ACK- . 0, 1 2 ( , ). - . . 3.11 . , 0, 0 , - 3 , .
, m . , , .. .
. 3.12 SR-ARQ m=2 , .. .
GO-Back-N ; ( , ). - .