BlueBox это увеличение ACK Timeout в устаревших стандартах 802.11 b/g
https://www.air-stream.org/technical...distance-links
В стандарте 802.11n был предложен новый механизм Block-ACK. Проблема, потому что фреймы группируются в блоки по 64 штуки.
Block-ACK Mechanism. Rather than sending an individual acknowledge following each data frame, 802.11n introduces the technique of confirming a burst of up to 64 frames with a single Block ACK (BA) frame.
https://www.air-stream.org/technical...distance-links
ACK Timeout: Clearly if the ACK timeout is shorter than the time it takes for the end of the last data packet (+ SIFS) to propagate to the receiver + the start of the ACK for that packet to propagate back to the sender, then the sending MAC will assume that the packet has been lost and will unnecessarily retransmit the data packet. The retransmitted packet will end up colliding with the ACK that is on its way back, inducing the back-off part of the protocol thus reducing throughput. If, conversely, the ACK timeout is set too long, the transmitter waits unncesessarily long before retransmitting any lost frames and thus reduces the throughput of the link (more important as the bit error of the environment increases.) Similar conclusions can be drawn about the CTS timeout, however RTS/CTS is only for reducing collisions with hidden nodes and can be turned off in the majority of cases. Most implementations assume the IEEE recommended one-way Air Propagation Time of 1 µs, thus tune the ACK Timeout of their devices to 300 meters. This is the maximum distance that high throughput can be achieved between a local network of IEEE 802.11b compliant devices out of the box. The links will still work over longer distances, but throughput will drop as the distance increases.
Block-ACK Mechanism. Rather than sending an individual acknowledge following each data frame, 802.11n introduces the technique of confirming a burst of up to 64 frames with a single Block ACK (BA) frame.
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