8 Part A: Introduction MB8100-00-00-806 © TEL 2003Power SavingThe TB8100 base station can save power by switching off parts of its circuitry.The standard base station has a limited ability to reduce the current that the basestation uses, but the Power Saving Modes license lets you configure threedifferent power saving modes. This gives greatly increased flexibility and makesit possible to get the power savings needed with a minimum sacrifice in qualityof service.Note: Power saving only occurs when the base station is battery-powered. It is not available if the PMU supplies more than one basestation.Power savingmodesA base station with a Power Saving Modes license can operate in Normal,Sleep, and Deep Sleep modes. These modes are enabled and configured in theService Kit.The base station begins in Normal mode. If the base station is idle (receives novalid signal) for a defined length of time, it switches to Sleep mode, which savesmore power. If the base station is idle for a further defined length of time, itswitches to Deep Sleep mode, saving even more power. When it receives avalid signal, it reverts to Normal mode.Both receiver and transmitter contribute to the power saving.The receiver is switched off, and then periodically switched back on. If itdetects a valid signal, it stays on, otherwise it is switched off again. The poweramplifier is always off when the base station is not transmitting. In power saving,other parts of the transmitter circuitry are switched off as well. The longer theTx keyup time you select, the more circuitry is switched off.Quality of service The more power saved, the greater the effect on the quality of service. At thebeginning of a call, the radio user needs to press PTT and wait before speaking,to give enough time for the receiver to come back on and for the transmitterto key up.Configuringpower savingYou configure power saving when you define the channel profile that the basestation will use. For each mode, you specify Rx cycling (how long the receiverstays switched off before it wakes up to check if there is a valid signal and theTx keyup time. In addition, you specify how long the base station must be idlebefore it enters Sleep and Deep Sleep modes. The exact amount of power savedvaries, depending on the model of base station and the pattern of traffic.
