Hi,
In an assignment I'm supposed to introduce packet errors and bit erasures in the packets.packet errors I can do.Bit erasures mean we have no idea if its a 1 or a 0.how can I introduce something other than a 0 or a 1 in a bit?

This question didn't make much sense to me at all.

> can I introduce something other than a 0 or a 1 in a bit?
A bit can only be either a 1 or a 0, or you can think of it as either on or off.

Thats what I'm saying too.Let me explain bit erasure.

Lets say I transmit 01001101
theoretically, I recieve 01?01?01
ie. I dont know those bit values...though I'm in doubt now how thats even possible.but thats what bit erasure means.

this should help..
http://en.wikipedia.org/wiki/Binary_erasure_channel

still need help with this :(

Taking this example,

Lets say I transmit 01001101

Does erasure mean you receive
0101101
Send 8, got 7

Or does it mean
01011101
The data has been 'erased' because the bit has been flipped in transmission.

Flipping a bit is just xor