Hello : 2008/6/4 Miklos Maroti <[EMAIL PROTECTED]>:
> Hi Zhang, > > >> Yes. The PacketTimeStamp interface is used to access the transmit or > >> receive time of the packet. If you want to embed a time stamp inside > >> the packet then you need to use the TimeSyncAMSend and TimeSyncPacket > >> interfaces of the SimSyncSend component. > > > > i understand , when use the TimeSyncAMSend interface to send a packet , > it > > also performs sender-receiver time synchronization besides send the > packet. > > but i still have some puzzles . if the sender and receiver are turned on > all > > the time and sleep periodically , there is no need of time synchronzation > > and the information of time have no significance to the motes. am i > right > > No. The TimsSyncAMSend is a time synchronization primitive and has > nothing to do with asynchronous LPL. If you want to establish > synchronized global time across all motes (regardless if you use LPL > or not) to be able to correlate external events, then you need time > synchronization. Please read the Flooding Time Synchronization > Protocol paper. that is to say this is the time synchronization between the sender and receiver , not the whole network ? i have seen the TimeSyncAMSend, when you send a packet , you shou give an parameter "event_time" in the command send . i can't understand the function of the parameter . it says that "parameter holds the time of some event as expressed in the local clock of the sender." , what dose the "some event " mean ? what should i set it to ? when the receiver receive the packet sended using the interface TimeSyncAMSend , what does it use the parameter event_time do ? can you explain how does the sender and the receiver realize time synchronization detailedly ? -:) i am so sorry , i still can't understand . > > > > ? what is the aim when you implement the driver ? do you want to use it > for > > lowpowerlistening ? because the current implementation of lowpower > listening > > is asynchronous , not synchronous (the sender know when the receiver > wake > > up , and there is no need to send the wake up packet before send the > useful > > data ) . i see the lpl of rf230 has been implemented , which kind does > it > > belong to ? do it use time synchronization in implementation of LPL ? > > No, they are completely independent. > > > i think you have implemented the time synchronization , so i want to know > > the arithmetic of time synchronization you use . > > Do you know which implementation of time synchronization suppose rf230 ? > > What do you mean by arithmetic of time synchronization? By the way, > only the sender-receiver time synchronization primitive is > implemented. FTSP will be ported to use this primitive. is there some time synchronization which supports rf230 implemented in tinyo-2.x ? > > >> Not yet. a TEP is coming out soon. You should have no problem using > >> the components I pointed out. The interface files have the necessary > >> documentations. > > > > is rf230 supposed by CTP ? > > What is CTP? Collection Tree Protocol . it is a muliti-hop route protocol . > > > Best, > Miklos > -- zhang jiwen
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