wiki:802.11/MAC/Upper/MACHighFramework/Scheduler

Version 1 (modified by chunter, 8 years ago) (diff)

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The 802.11 Reference Design and its documentation are under active development by the Mango team. The current release should be considered a beta- updates with bug fixes, API changes, new features and other refinements will be posted frequently. Please check the downloads page for the latest updates and post any questions about the design to the forums.

Scheduler

The MAC High Framework has the ability to allow an upper-level MAC to schedule the execution of an arbitrary function at some point in the future. Schedules are broken up into two broad categories: coarse and fine. The coarse scheduler can be used to schedule events with an accuracy of + or - 100ms, while the fine scheduler can be used to schedule events with an accuracy of + or - 100µs. The use of the fine schedule does increase the workload of the processor as it has to poll the scheduled events more often.

Example uses of scheduler

Periodic Beacon Transmissions in the Access Point Upper-level MAC

The AP implementation periodically transmits a beacon MPDU. It uses the scheduler to periodically call its own function that creates and submits a beacon MPDU to the transmit queue.

Timeout during Active Scan process in the Station Upper-level MAC

When performing an active scan to look for nearby access points, the station implementation transmits a probe request followed by waiting for probe responses. This wait is implemented via the scheduler. When the scheduler calls the registered callback, the station implementation jumps to a new channel to continue the process.

Local Traffic Generation in the MAC High Framework