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Test 1. Solution. I/. OSI and Layered Architecture. Sergeants can talk indirectly with other sergeants and directly with privates and lientenants B. General->Colonel->Major…->Private-> Private->Sergeant->Lieut…->General C. Link Layer Error-free point-to-point connection
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Test 1 Solution
I/. OSI and Layered Architecture • Sergeants can talk indirectly with other • sergeants and directly with privates and • lientenants • B. General->Colonel->Major…->Private-> • Private->Sergeant->Lieut…->General • C. Link Layer • Error-free point-to-point connection • Network Layer • Connectivity anywhere in the net by Routing • and universal naming (IP name mapping) • Transport Layer • Error-free end-to-end connection General Colonel Major Captain Lieut Sergeant Private General Colonel Major Captain Lieut Sergeant Private
Frequency and Bandwidth (A) cos(A)cos(B)= ½ (cos (A+B) + cos(A-B)) Lowest frequency cos(1240k)cos(0)= ½ (cos (1240k+0) + cos(1240-0)) ½ (cos (1240k) + cos(1240k)) Highest frequency cos(1240k)cos(5k)= ½ (cos (1240k+5k) + cos(1240-5k)) ½ (cos (1235k) + cos(1245k)) Keeping higher subbands -> 1240k to1245k I’m being sloppy with the frequency. (should be 2piF not F)
Frequency and Bandwidth (B) Encoding a digitized talk show over an analog medium would use a modem-type encoding technique ASK PSK FSK or some combination of these
T, duration of 1 bit IV. Encoding (A) high value Time low value 1 1 1 0 1 0 0 Part 1 Manchester Encoding
FSK 1 1 1 0 1 0 0 Frequency (FSK)
ASK 2 bits per baud 01 00 11 10 transmission 11 10 01 00
IV. Encoding B 64 levels -> 6 bits per sample 10kHz -> 20kHz sampling rate 6 bits/sample x 20k samples/sec = 120k bits/sec 120 secs in 2 minutes -> 120 x 120k bits = 14,400,000 bits
Analog to Digital 0.3 = 0000 0000 0.25 0001 0.5 0010 0.75 0011 1.0 0100 1.25 0101 1.5 0110 1.75 0111 2.00 1000 2.25 1001 2.5 1010 2.75 1011 3.0 1100 3.25 1101 3.5 1110 3.75 1111 4.0 1.3 = 0100 1.8 = 0110 2.05 = 0111 3.55 = 1101 0100 0111 0110 0000 1101