Describe the most popular wireless Internet access technologies today. Compare and contrast them. What is the key distinguishing difference between a tier-1 ISP and a tier-2 ISP? How long does it take a packet of length 1,000 bytes to propagate over a link of distance 2, 40 km, propagation speed 2.4 astir 10^8 m/s, and transmission rate 2 Mbps? More generally, how long does it take a packet of length L to propagate over a link of distance d, propagation speed s, and transmission rate R bps? Does this delay depend on packet length? Does this delay depend on transmission rate