Multipath ambiguity

In Wi-Fi multi path used to mean the way that signals traversing different spatial paths arrive at different times. Before MIMO this was considered an impairment to the signal, but with multiple antennas this ‘spatial diversity’ is used to deliver the huge speed increases of 802.11n over 802.11g.

This week has seen a big PR push on a different “multipath,” embodied in IETF RFC 6824, “TCP Extensions for Multipath Operation with Multiple Addresses,” (MPTCP). Of course you know that one of the robustness features of IP is that it delivers packets over different routes, but RFC 6824 takes it to another level, as described in this article in Ars Technica, and this one at MIT Technology Review.