[Tinyos-help] time synchronization

[jiwen zhang]

Hello all :

2008/6/3 Miklos Maroti <mmaroti at math.u-szeged.hu>:

> Hi Zhang,
>
> > Hello all :
> >    i see some files in chips/rf230 , i see some words like TimeSyncPacket
> ,
> > so i think maybe the time synchronization is implementated in rf230 , am
> i
> > right ?
>
> 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
? 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 ?

>
> >    if yes , i want to know which arithmetic does it use ?
>
> What do you mean? The time resolution is currently 1 millisecond
> (continnuous) and 1 microsecond (stops of the mote stops).

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 ?

>
>
> > maybe there are a corresponding paper , can someone give me a reference ?
>
> 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 ?

>
>
> Best,
> Miklos
>



-- 
zhang jiwen
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