In simple terms, DHCP determines if your IP is static or dynamic and the length of time an IP address is assigned. Dynamic Host Configuration Protocol is controlled by a DHCP server. Your router can be a DHCP server...and if you're on a home network, it most likely serves this purpose.
Researchers report that the average adolescent needs eight and a half to nine and a half hours of sleep each night. But in a poll taken in 2006 by the National Sleep Foundation, less than 20 percent reported getting that much rest on school nights.
Sleep has four stages, each stage lasts 90 minutes. Stage 3& 4 are the deep sleep cycle. To have a good sleep , you need 3-4 hours of deep sleep and the balance would be light sleep. If you wake up several times,that would interfere with sleep quality. Total sleep should be around 8 hours although it is dependent on the individual.