when half the transmission queue is full. When a neighbor is heard to
be congested, the rtmetric of that node is inflated to avoid sending
more traffic in its direction.
Fixed problems with beacon intervals: intervals are now not reduced
when a path gets significantly worse, only when they get better.
reset so that a new probing period can produce more up-to-date
estimates. Added a congestion mechanism whereby a neighbor can be
marked as being congested for a period of time, during which the ETX
for the neighbor will be artificially inflated.
computed only over the actual samples, not over the entire
buffer. Also, the initial link estimate is much more conservative now
(16 transmissions) to favor links that have been probed, and which
therefore are likely to have better ETXs.
cycling layer. This definition was previously held in net/mac/mac.h,
with the name MAC_CONF_CHANNEL_CHECK_RATE. But since the rate is used
by the radio duty cycling layer, it makes more sense to change its
name to reflect this. Also, the configuration option should be tied to
the netstack configuration instead.
So the new configuration option is called
NETSTACK_CONF_RDC_CHANNEL_CHECK_RATE.
* Added an optional "keep alive" mechanism whereby an idle network is
periodically probed by dummy packets to maintain a recent quality
metric when there is no traffic.
* Bugfix in when new routing metrics should be advertised
* Rewrote the ACK logic so that a queuebuf is not allocated for each
ack, only for those acks generated by the sink node.
* Updated the wrap-around logic for sequence numbers: when a sequence
number wraps, it won't go back to 0. Instead, it wraps to 128. This
allows us to understand when a node has rebooted: when its seqno is <
128, it has recently rebooted.
* Loop detection and untangling. Now uses in-band loop detection that
works.
* Link quality estimation. Now starts with a conservative /
pessimistic estimate for new links.
* Retransmissions. MAC layer and network layer retransmissions are now
decoupled.
* Loss handling. Deals better with losses now.
* Concurrent applications. Each connection now maintains its own
neighbor table with separated cost to sink estimates for each
connection.
