Hi Jose, we omitted the timekeeping flag as nodes will select time source neighbor according to RPL parent. However you seem to be right if we want to fully comply with the standard. In minimal we define a single slot which is advertised by the EB, the slot is shared-tx and rx. The 15.4 standard as you say indicates
"RX links shall have the Timekeeping linkOptions bit set." (assuming the shall is understood as a MUST) as for your second point. In minimal we only advertise one link which is the same for all listening nodes. At the beginning of the network, this link is also the RX link for all nodes joining to the advertising node. And according to the 15.4 std, it must be set to timekeeping as you indicate. "...Note that a device sending Enhanced Beacons to advertise a TSCH PAN should set the Timekeeping bit in the Link Option field (as described in 5.2.4.14) for the joining devices' receive link so that joining devices can maintain time synchronization until additional time source neighbors are configured by a higher layer...". we will amend the current draft with your comments. thanks you very much! X 2015-06-19 13:58 GMT+02:00 José Ángel Miranda <[email protected]>: > HI, > > When reading the new updated minimal, we have observed that the > timekeeping bit within the IE TSCH Slotframe and Link is not set: "...The > "Timekeeping" flag is never set, since the time source neighbor is selected > using the DODAG structure of the network..." > > If you take a look to the current standard: > - Point 5.2.4.14, TSCH Slotframe and Link IE: "...RX links shall have the > Timekeeping linkOptions bit set...". > - Point 5.1.4.2a, Synchronization in a TSCH PAN: "...Note that a device > sending Enhanced Beacons to advertise a TSCH PAN should set the Timekeeping > bit in the Link Option field (as described in 5.2.4.14) for the joining > devices' receive link so that joining devices can maintain time > synchronization until additional time source neighbors are configured by a > higher layer...". > > Therefore, the link within the beacon sent by the (PAN)coordinator should > be set as timekeeping too based on the current standard. > > Cheers, > Jose. >
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