Hi, I also made some tests a few months ago with an IRIS mote, stressing the packet size and periodicity of tranmission. The conclusion is quite obvious: larger packets = higher data loss (with the same transmission period). I tested several combinations of packet sizes and time periods but sending 114Bytes: - every 250ms between 2 motes installed with 4 meters of distance between them, I get 100% PRR (receive every packet sent) during a 15 minutes period - every 250ms between 3 motes installed with 4 meters of distance between them (forming a triangle), I get at least 20% of packet lost during a 60 minutes period
Anyway with a payload of 114 and sending every 250ms you would only get 456Bytes (assuming you could get 100% receive rate), which is far from your objective. Regards, Joao On 2009/02/03, at 13:52, Razvan Musaloiu-E. wrote: > Hi! > > On Tue, 3 Feb 2009, kiseop Lee wrote: > >> Hello, >> How does the TestSerial send large payload datas to host-PC by >> RS-232 ? >> >> I have found that "TOSH_DATA_LENGTH 28" into CC2420.h file is used >> in Packet.maxPayloadLength(). >> But I have modified it to 1300 and the test_serial_msg_t has a >> member array >> which is composed >> with 1200 bytes. Now, it does not operate. >> >> I want to send 1200bytes per second to Host-PC by RS-232 and RF. >> in this stage, I am testing only RS-232 and at next stage, I will >> send these >> by RF. >> >> Do you know this problem? >> > > Bad news: you cannot make the payload that big. All the send/receive > interfaces the type uint8_t for the length. Moreover, for C2420 the > maximum value for TOSH_DATA_LENGTH cannot exceed 114 (or 115) bytes > because the internal buffer of chip is 128 bytes (including the > headers). > > All the best! > Razvan ME > _______________________________________________ > Tinyos-help mailing list > [email protected] > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
