  Today's increasing demand for wirelessly uploading a large volume of User
Generated Content (UGC) is still significantly limited by the throttled
backhaul of residential broadband (typically between 1 and 3Mbps). We propose
BaPu, a carefully designed system with implementation for bunching WiFi access
points' backhaul to achieve a high aggregated throughput. BaPu is inspired by a
decade of networking design principles and techniques to enable efficient TCP
over wireless links and multipath. BaPu aims to achieve two major goals:1)
requires no client modification for easy incremental adoption; 2) supports not
only UDP, but also TCP traffic to greatly extend its applicability to a broad
class of popular applications such as HD streaming or large file transfer. We
prototyped BaPu with commodity hardware. Our extensive experiments shows that
despite TCP's sensitivity to typical channel factors such as high wireless
packet loss, out-of-order packets arrivals due to multipath, heterogeneous
backhaul capacity, and dynamic delays, BaPu achieves a backhaul aggregation up
to 95% of the theoretical maximum throughput for UDP and 88% for TCP. We also
empirically estimate the potential idle bandwidth that can be harnessed from
residential broadband.
