Thank Marcus. "packet decoding" recovers message from received packet
and i got false from crc.py def check_crc32(s): if len(s) < 4: return (False, '') msg = s[:-4] #print "msg = '%s'" % (msg,) actual = digital.crc32(msg) (expected,) = struct.unpack(">I", s[-4:]) #print "actual =", hex(actual), "expected =", hex(expected) * print actual == expected* return (actual == expected, msg) 2016-02-21 20:52 GMT+09:00 Marcus Müller <marcus.muel...@ettus.com>: > Dear Sang Hyuk Kim, > > what "packet decoding" are you specifically talking about, and could you > show us the code you've modified? > > Best regards, > Marcus > > > On 21.02.2016 12:32, SangHyuk Kim wrote: > > Hi, I transmit simple text file using two USRP N210 > > Tx) > file source -> packet encoding -> mod(GMSK) -> usrp sink > > Rx) > usrp source -> demod(GMSK) -> packet decoding -> file sink > > > To make corrupt packet, I tried to modify part of crc check > > I guess if the crc of received packet doesn't match with original one, > receiver would discard the packet. > > However, I found receiver accepts every packet even if crc check returns > 'false'. > (I expected receiver accepts packet only pass crc check by 'true') > > Why it always return false and how can I corrupt packet with other ways ? > > > _______________________________________________ > Discuss-gnuradio mailing > listDiscuss-gnuradio@gnu.orghttps://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > >
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