ation ▁characteristics ▁Sign al ▁propag ation ▁on ▁the ▁ 3 3 ▁cent imeter ▁band ▁is ▁very ▁dependent ▁on ▁the ▁transm itting ▁and ▁receiving ▁anten na ' s ▁line ▁of ▁sight . ▁Because ▁of ▁this , ▁many ▁wide - area ▁coverage ▁systems ▁like ▁repe aters ▁are ▁located ▁on ▁top ▁of ▁large ▁hills ▁and ▁mountains ▁which ▁over look ▁a ▁vast ▁area . ▁This ▁ens ures ▁that ▁the ▁transm itting ▁anten na ▁is ▁higher ▁than ▁terrest rial ▁ob stru ctions ▁such ▁as ▁trees ▁and ▁buildings . ▁Assuming ▁that ▁the ▁transm itting ▁anten na ' s ▁w avel ength , ▁height ▁above ▁average ▁terrain , ▁and ▁effective ▁radi ated ▁power ▁is ▁equal , ▁a ▁transm itted ▁signal ▁on ▁ 3 3 ▁cent im eters ▁will , ▁generally ▁speaking , ▁usually ▁travel ▁about ▁ 3 / 4 ▁of ▁the ▁distance ▁that ▁the ▁same ▁signal ▁would ▁if ▁transm itted ▁on ▁the ▁ 7 0 ▁cent imeter ▁band . ▁▁ ▁The ▁reader ▁is ▁ad vised ▁to ▁note ▁that ▁receiver ▁front - end ▁noise ▁figure ▁and ▁anten na ▁gain ▁are ▁the ▁defining ▁factors ▁in ▁line - of - s ight ▁signal ▁propag ation ▁in ▁the ▁local ▁area . ▁ ▁The ▁ 3 3 ▁cent imeter ▁band ▁offers ▁excellent ▁building ▁pen etr ation ▁characteristics ▁since ▁the ▁w avel ength ▁is ▁relatively ▁small ▁and ▁can ▁fit ▁through ▁windows ▁more ▁easily ▁than ▁signals ▁lower ▁in ▁frequency . ▁ ▁In ▁many ▁areas , ▁the ▁ 3 3 ▁cent imeter ▁band ▁also ▁has ▁a ▁very ▁low ▁noise ▁floor ▁as ▁compared ▁to ▁bands ▁lower ▁in ▁frequency ▁.