The MRF24WB0M / MRF24WG0M supports two power-saving modes – sleep and hibernate.
|
Mode |
Description |
|
Sleep |
This mode is used when in PS Poll mode where the MRF24WB0M / MRF24WG0M wakes itself up at periodic intervals to query the network for receive messages buffered by an Access Point. See listenInterval in the tWFCAElements structure. When in sleep mode the MRF24WB0M / MRF24WG0M transmitter receiver circuits are turned off along with other circuitry to minimize power consumption. Sleep mode is entered periodically as a result of the Host CPU enabling PS Poll mode. |
|
Hibernate |
This mode effectively turns off the LDO of the MRF24WB0M / MRF24WG0M for maximum power savings. MRF24WB0M / MRF24WG0M state is not retained, and when the MRF24WB0M / MRF24WG0M is taken out of the Hibernate state it performs a reboot. Hibernate mode is controlled by toggling the HIBERNATE pin on the MRF24WB0M / MRF24WG0M module (high to enter hibernate, low to exit). This mode should be used when the application allows for the MRF24WB0M / MRF24WG0M module to be off for extended periods of time. |
802.11 chipsets have two well known operational power modes. Active power mode is defined as the radio always on either transmitting or receiving, meaning that when it isn't transmitting then it is trying to receive. Power save mode is defined as operating with the radio turned off when there is nothing to transmit and only turning the radio receiver on when required.
The power save mode is a mode that requires interaction with an Access Point. The access point is notified via a packet from the Station that it is entering into power save mode. As a result the access point is required to buffer any packets that are destined for the Station until the Station announces that it is ready to once again receive packets. The duration that a Station is allowed to remain in this mode is limited and is typically 10 times the beacon interval of the Access point.
If the host is expecting packets from the network it should operate in Active mode. If however power saving is critical and packets are not expected then the host should consider operating in power save mode. Due to the nature of Access points not all behaving the same, there is the possibility that an Access point will invalidate a Stations connection if it has not heard from the Station over a given time period. For this reason power save mode should be used with caution.
The 802.11 name for power saving mode is PS-Poll (Power-Save Poll).
|
Name |
Description |
|
Functions and variables accessible by the stack application | |
|
Functions and variables internal to the module | |
|
The following table lists functions in this documentation. | |
|
The following table lists types in this documentation. | |
|
The following table lists variables in this documentation. |
|
|
Name |
Description |
 |
Returns state of power save mode | |
|
|
Enable or disable power save mode |
|
|
Name |
Description |
 |
Enumeration of valid values for WFSetPowerSaveMode() | |
|
|
Power Save Mode Request Structure |
|
|
Name |
Description |
 |
Enable or Disable Power Save Mode | |
|
|
Power save states | |
|
|
Status of PS-Poll | |
|
|
TRUE if need to put device back into PS-Poll sleep mode. else FALSE |