On Fri, Feb 19, 2010 at 10:15 PM, <[email protected]> wrote:
> Hi,
>
> Please help me understand the following uncertainties regarding 4 bit link
> estimation (4bitle):
> 1) 4bitle is using both data-driven and beacon approach to estimate link
> qualities in terms of ETX. Data-driven is estimating bidirectional link
> quality since it leverages ACK, whilst beacon is only measuring inbound link
> quality. Is it problematic to combine these two estimated ETX into a single
> ETX? What does this single ETX mean? Inbound link quality, or bidirectional?
Bi-directional. Beacons are only used for bootstrapping.
> 2) In beacon based link estimation of 4bitle, each packet from upper layer
> is slapped with a header containing sequence number information needed to
> compute link quality prior to transmission. However, the sequence number has
> only 8 bits (see below). Is this sufficient for beacons more than 255?
> typedef nx_struct linkest_header {
> nx_uint8_t flags;
> nx_uint8_t seq;
> } linkest_header_t;
You need to detect and handle sequence number wrap-around.
- om_p
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