idle state

The idle state is generally used to save energy. Corresponding modes are used in transmission technology devices, but especially for power management in computers, laptops, notebooks, tablet PCs, smartphones, televisions and other consumer electronics devices.

1. In computer technology, laptops, notebooks and tablet PCs, Idle Mode is an energy-saving function of power management that extends battery life.
   

   Hibernation mode activated during shutdown in Windows XP

   This operating state, also known as suspend-to-disk, can be activated in various operating systems when the personal computer( PC) is switched off and means that, unlike standby mode, all data is saved to the hard disk. In addition to Idle Mode and Standby Mode, there is also Sleep Mode, Hibernation, Power Save Mode and Active Mode.
2. In mobile communication, a mobile station enters idle mode when it has no active network connection. The mobile station independently searches for a radio cell suitable for reception, whose BCCH, CCCH and CBCHorganization channels are then constantly received and evaluated. For mobile networks, there is the Power Saving Mode( PSM), which can be used to extend the battery life of mobile devices that do not communicate regularly. In trunked radio, the Idle State means that there is currently no user data traffic, but there may be organization data traffic.
3. In 802.11WLANs, there is a Power Save mode in which the WLAN end device enters an idle state. In this state, the access point( AP) buffers incoming data packets and transmits them to the WLAN station as soon as it notices that the end device is actively working again. In power-save mode, the WLAN station switches off its transmitting and receiving equipment to save energy. A station requires only a small amount of energy for receiving, but a relatively large amount for transmitting. It therefore saves energy if the access point informs the WLAN station of the cached frames with the Delivery Traffic Indication Message( DTIM), and the station is not constantly active and receiving the frames.
4. In data communication, the idle state is indicated when there is no data to be transmitted on an existing connection. The term comes from X.25 data packet switching and trunked radio. In the idle state, the data link layerservices are not available for data exchange. The physical layer may be in the data transfer state, but layer 2 cannot send or receive commands or messages. In the idle state, the communication instance of the link layer is not able to operate according to the agreed protocol.