Cross-layer rate adaptation mechanism for WLAN
AssigneeIndustrial Technology Research Institute
InventorsLi-Chun Wang, Kuang-Nan Yen, Ming-Bing Chen, Wei-Cheng Liu, Yu-Ren Yang, Ping-Jung Huang
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Abstract
A cross-layer rate adaptation mechanism for wireless local area network (WLAN) can obtain the channel state by calculating the Eb/N0 ratio of ACK frame transmitted from the receiver side. The mechanism determines the transmission rate of the next frame by referring to a predefined reduced mode table. When receiving an ACK frame fails, the mechanism can automatically lower the transmitting rate of the next transmission. Therefore, the method can reduce the damage to the system when ACK frame failure happens.
Claims8
A cross-layer rate adaptation mechanism for wireless local area network (WLAN), applied to a channel, comprising the steps of:
- predetermining a packet error rate;
- establishing a reduced mode table at a physical layer (PHY) of a transmitting end when the packet error rate is met, wherein the reduced mode table includes a plurality of transmission rates of the physical layer and a plurality of corresponding signal-to-noise (S/N) ratios;
- transmitting a packet from a medium access control (MAC) layer of the transmitting end to a receiving end at an initial transmission rate;
- determining whether an acknowledge (ACK) frame from the receiving end is successfully received through the medium access control layer of the transmitting end;
- evaluating an signal-to-noise ratio of the ACK frame by the medium access control layer of the transmitting end when the ACK frame is successfully received, and transmitting other packets according to an adjusted transmission rate corresponding to the evaluated signal-to-noise ratio;
- and
- transmitting the next packet at an adjusted transmission rate lower than a previous transmission rate from the transmitting end when receiving the ACK frame fails.
Dependencies are inferred from the claim text.