Method of providing notification for battery power conservation in a wireless system

A method of executing battery power conservation procedure between an access terminal (AT) and an access network (AN) in a wireless communication system, the method comprising:

• transmitting a notification message to the AN, wherein the notification message includes at least one of battery life information and a power-saving mode request;
• receiving a confirmation message from the AN, wherein the confirmation message includes a determined power saving mode based on the at least one of battery life information and the power-saving mode request;
• and
• entering the power-saving mode according to the determined power saving mode,
• wherein the notification message further includes a LeftOverBatteryIndicatorIncluded field, a LeftoverBatteryLifeIndicator field, a PowerSavingModeIncluded field, and a PowerSavingMode field.