Communication Systems Engineering Episode 2 Part 9 pptx

Ngày tải lên: 07/08/2014, 12:21

... Called “co-set leader” CC CSyndrome eeC eC S eC eC S eS M M M nK nK 12 1 12 1 1 22 2 2 21 21 L M ++ ++ − − −− () () M = 2 K Eytan Modiano Slide 5 Channel Capacity • The capacity of a discrete ... sliding window of input Delay Delay + + + C i C i+1 U K C (2K) = U (2K) U (2K -2) , C (2K+1) = U (2K+1) U (2K) U (2K-1) + + + + mod ( 2 ) addition ( 1+1=0 ) Eytan Modiano Slid...

Ngày tải lên: 07/08/2014, 12:21

... (TO), go to 2 RETRANSMISSION BECAUSE OF ERRORS FOR GO BACK 4 ARQ 0 3 4 t 1 SN RN 0 1 1 1 1 2 x 3 4 3 Window Node A Node B (0,3) (1,4) (2, 5) 2 1 2 1 Packets 0 1 2 3 delivered ... of Go Back 7 ARQ SN 0 3 4 5 t 1 6 RN 0 1 2 3 5 Window (0,6) (1,7) (5,11) (2, 8) (3 ,9) Node A Node B 2 0 5 Packets delivered 0 1 2 3 4 5 • Note that packet RN...

Ngày tải lên: 07/08/2014, 12:21

Ngày tải lên: 07/08/2014, 12:21

... can be shown that, E[n] = T E[n ] = T + ( T) = E[(n-E[n]) ] = E[n ]-E[n] = T 22 22 22 λ λλ σλ Eytan Modiano Slide 19 Example (fast food restaurant) • Customers arrive at a fast food restaurant ... we can tolerate Circuits P B 20 1% 15 8% 7 30% Eytan Modiano Slide 22 Delay formulas • M/G/1 • M/M/1 • M/D/1 DX=+ − λµ µλ / DX=+ − λµ µλ / ( )2 DX X =+ − λ λµ 2 21(/) Delay components:...

Ngày tải lên: 07/08/2014, 12:21

... group transmits (1 ,2, 3,4) (1 ,2, 3) 4 success collision (2, 3) collision idle collision (2, 3) success success Notice that after the idle slot, collision between (2, 3) was sure to happen ... duration packets) – P(success) = e -g x e -g = e -2g – Throughput (success rate) = ge -2g – Max throughput at g = 1 /2, Throughput = 1/2e ~ 0.18 – Stabilization issues are simila...

Ngày tải lên: 07/08/2014, 12:21

... for mixed voice and data Slot 1 2 3 4 5 6 frame 1 frame 2 frame 3 frame 4 frame 5 15 3 20 2 15 7 3 9 7 9 7 9 18 7 3 15 9 6 18 idle idle idle idle 2 3 3 6 Eytan Modiano Slide ... Eytan Modiano Slide 9 ττ τ Approximate model for CSMA/CD • Simplified approximation for added insight • Consider a slotted system with “mini-slots” of duration 2 τ 22 22...

Ngày tải lên: 07/08/2014, 12:21

... called directed arcs. 1 2 3 4 N = {1 ,2, 3,4} A = {(1 ,2) , (2, 1),(1,4), (4 ,2) , (4,3),(3 ,2) } • Directed walk: (4 ,2, 1,4,3 ,2) • Directed path: (4 ,2, 1) • Directed cycle: (4 ,2, 1,4) • Data networks ... n2, ,nk) in which each adjacent node pair is an arc. • A path is a walk with no repeated nodes. 1 2 4 3 1 2 4 3 Walk (1 ,2, 3,4 ,2) Path (1 ,2, 3,4) Eytan Modia...

Ngày tải lên: 07/08/2014, 12:21

... 4.2BSD - 198 3 First widely available release – 4.3BSD Tahoe - 198 8 Slow start and congestion avoidance – 4.3BSD Reno - 199 0 Header compression – 4.4BSD - 199 3 Multicast support, RFC 1 323 ... addresses) – Allocate a block of contiguous addresses E.g., 1 92 . 4.16.1 - 1 92 . 4. 32. 155 Bundles 16 class C addresses The first 20 bits of the address field are the same and are esse...

Ngày tải lên: 07/08/2014, 12:21

Ngày tải lên: 07/08/2014, 12:21