课程名称︰无线网络基础与应用
课程性质︰选修
课程教师︰蔡欣穆
开课学院：电资学院
开课系所︰资工所、网媒所
考试日期（年月日）︰2016.03.18
考试时限（分钟）：
试题 :
■ Compare the overhead of 1) enabling RTS/CTS and 2) disabling RTS/CTS for
– A 1500-byte packet sent at 6mbps
– A 1500-byte packet sent at 54mbps
■ Packet format in 802.11a (base rate = 6mbps)
– Assume that the average backoff value is 16 slots
– Time slot = 9 us
– DIFS = 34us, SIFS = 16us
– PLCP header: 13 symbols = 52us
– RTS: 20 bytes
– CTS: 20 bytes
– ACK: 14 bytes
– MAC header: 34 bytes