Hello Omprakash :
maybe i don't express my problems distinctly .
1 . the field "etx" in the struct route_info_t . Is it the current
node's ETX through it's parent ? or is it the parent's ETX ?
2. what are the meaning of commands "getNeighborLinkQuality(uint8_t
neighbor)" and "getNeighborRouteQuality(uint8_t neighbor)" in the interface
of CtpInfo ?
in my opinion , the command "getNeighborLinkQuality" returns the ext
between the current node and one neighbor in routetable , and the
command
"getNeighborRouteQuality" returns the etx between current node and
root throught the neighbor . am i right ? can you expalin it detailedly ?
3 . i have seen the implementation of the interface CtpInfo , and the
command getNeighborRouteQuality which is
command uint16_t CtpInfo.getNeighborRouteQuality(uint8_t n) {
return (n < routingTableActive)? call
LinkEstimator.getLinkQuality(routingTable[n].neighbor) +
routingTable[n].info.etx:0xfffff;
}
if it returns the value of the neighbor's ETX through this neighbor's parent
, i think it should be changed into :
command uint16_t CtpInfo.getNeighborRouteQuality(uint8_t n) {
return (n < routingTableActive)? routingTable[n].info.etx:0xfffff;
}
because routingTable[n].info.etx is the neighbor's ETX through this
neighbor's parent , why do you add the link quality between the current node
and this neighbor ?
thank you !!
2008/6/16 Omprakash Gnawali <[EMAIL PROTECTED]>:
> On Sun, Jun 15, 2008 at 8:54 PM, jiwen zhang <[EMAIL PROTECTED]>
> wrote:
> > Hello Omprakash :
> > I have some questions about the interface CtpInfo .
> > Firstly , i am puzzled to the meaning of some fields in routetable.
> > in the structure routing_table_entry (TreeRouting.h), there are some
> > information of the current node . the field of parent in route_info_t
> should
> > be the parent of one neighbor in the routetable , and what does the ETX
> mean
> > ? is it the the neighbor's parent's EXT or the neighbor's the ETX ?(the
> EXT
> > here should be the path metric to the root??) .
> >
> > i have seen the implementation of CtpInfo in CtpRoutingEngineP, and i
> have
> > interest to the command which get the neighbors' information.
> > command uint16_t CtpInfo.getNeighborLinkQuality(uint8_t n) {
> > return (n < routingTableActive)? call
> > LinkEstimator.getLinkQuality(routingTable[n].neighbor):0xffff;
> > }
> > command uint16_t CtpInfo.getNeighborRouteQuality(uint8_t n) {
> > return (n < routingTableActive)? call
> > LinkEstimator.getLinkQuality(routingTable[n].neighbor) +
> > routingTable[n].info.etx:0xfffff;
> > }
> > in my opinion , the command of getNeighborLinkQuality returns a value of
> the
> > quality between the current node and this neighbor in the routetable .
> > if the field of ETX in route_info_t is the neighbor's EXT to the root , i
> > think the command getNeighborRouteQuality returns a value of path metric
> > between the current node and the root node through this neighbor (which
> is
> > the sum of this neighbor's ETX to the root and the quility between the
> > current node and the neighbor node).
> >
> > the command Ctp.getEtx(uint16_t* etx) will return the value of the path
> > metric between the current node and the root through the node's parent. i
> > find there are some differencs with the way in
> > CtpInfo.getNeighborRouteQuality.
> > *etx = routeInfo.etx + evaluateEtx(call
> > LinkEstimator.getLinkQuality(routeInfo.parent));
> > and the function evaluateEtx() is
> > uint16_t evaluateEtx(uint16_t quality) {
> > return (quality + 10);
> > }
> >
> > i don't know whether i have expressed the problem distinctly , i think
> the
> > two ways have the difference of "10" . am i right ,Omprakash ? can you
> give
> > me an explain?
>
> Yes. The algorithms use the metric ETX*10 but the metric is encoded as
> (ETX-1)*10 in the packets.
>
> - om_p
>
--
zhang jiwen
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