Lub chaw cia khoom txawb yog ib hom khoom txee uas, tsis zoo li cov chav nyob ruaj khov, tuaj yeem txav mus los ntawm qhov chaw sib txawv. Feem ntau tsim los ntawm ntau ntu txuas nrog los ntawm cov kab ke khiav, cov koog no swb raws cov lem, tso cai rau tag nrho cov kev sib dhos yuav tsum tau rov qab.
Lub luag haujlwm tseem ceeb ntawm cov chaw khaws khoom txawb yog kom siv qhov chaw zoo tshaj plaws. Hauv cov chaw ua haujlwm ib txwm muaj lossis cov chaw hauv tsev, cov thawv ntim khoom feem ntau yog tsau rau ntawm phab ntsa thiab txav tsis tau; Piv txwv li, mobile units tuaj yeem hloov mus rau txhua qhov chaw khaws cia, ua kom siv tau qhov chaw zoo dua. Tsis tas li ntawd, cov chav nyob no tuaj yeem kho dua tshiab raws li qhov yuav tsum tau ua kom tau raws li qhov sib txawv cia xav tau.