Thomas Kunz
Systems and Computer Engineering
410
Snoop: Description of Protocol
ndesign does not
cache packets from MH to FH
–bulk of packet losses will be between MH and base
–but snooping on packets generates requests for
retransmissions at base much faster
than from remote FH
–enhance TCP implementation at MH with “selective ACK”
option:
nbase keeps track of
packets lost in a transmission window
nsends bit vector
back to MH to trigger retransmission of lost packets
nmobility
handling:
–when handoff is requested by MH or anticipated by base
station, nearby base stations begin receiving
packets destined for MH, priming their
cache
–caches synchronized during actual handoff (since nearby
bases cannot snoop on ACKs)