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| -rw-r--r-- | assignments/3/README.md | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/assignments/3/README.md b/assignments/3/README.md index 3d41c20..c11c158 100644 --- a/assignments/3/README.md +++ b/assignments/3/README.md @@ -232,14 +232,18 @@ Context: - Distance: 180 m - Frame: 1,024 bits -- Propagation Speed: 2\*10^8 m/sec +- Propagation Speed: 2 * 10^8 m/sec - Backoff intervals: multiple of 512 bits - Store and forward delay: 20-bit transmission time > a) What is the one-way propagation delay (including all repeater delays) between A and B in seconds? At what time is A's packet completely delivered at B? -> b) Now suppose that only A has a packet to send and that the repeaters are replaced with switches. Suppose that each switch has an 8-bit processing delay in addition to a store-and-forward delay. At what time, in seconds, is A's packet delivered at B? +- time = distance / speed (distance: 180 m, speed: 10^8 m/sec) +- Cable propagation: 180 m / (2 * 10^8 m/sec) = 0.0000009 seconds +- Three repeaters: 3 × (20 bits / 10^9 bps) = 0.00000006 seconds +- Total one-way delay: 0.00000096 seconds +> b) Now suppose that only A has a packet to send and that the repeaters are replaced with switches. Suppose that each switch has an 8-bit processing delay in addition to a store-and-forward delay. At what time, in seconds, is A's packet delivered at B? ## 2.4 802.11 RTS/CTS Transmission (10%) |