Maranello: Practical Partial Packet Recovery for 802.11, Bo Han and Aaron Schulman, Francesco Gringoli, Neil Spring and Bobby Bhattacharjee, Lorenzo Nava, Lusheng Ji, Seungjoon Lee, and Robert Miller, in Proc. NSDI'10, San Jose, CA, April 2010.
This is another paper which has built a system that works. There is no super deep theory behind it, but a lot of effort to implement something in a real environment. This is basically a partial packet recovery mechanism which is compatible with 802.11 and works as follows:
- the sender sends a packet to the receiver. Typically, if the packet is received correctly, an Ack is sent; if not, no Ack is sent, and after a time-out, the sender attempts a retransmission. In maranello, if the paper is not received correctly, the receiver still transmit an Ack, except it is a Nack with a checksum of blocks within the packets. Based on the checksum, the sender can retransmit only the corrupted blocks and not the whole packet.
This speeds up the retransmission and reduces the congestion on the air interface. As a consequence, throughput is roughly 50% higher than 802.11 and delay is significantly reduced.
The system is evaluated alongside traditional 802.11, which shows that both system can coexist peacefully.
This was pointed to me as an excellent paper by a Stanford faculty, and it did not disappoint indeed. I have no idea where the name Maranello comes from. I mean, I know of the city in Italy, but not how it relates to partial packet recovery.