Error in Data transmission from on end to another

[humdum]

I have a software which used to transmit messages thru wireless communication, lan, serial port. This software is usd to snd messages.

Now, There is another software similar to like this used to send messages via VSAT(satellite). when messages arives from this software there present some unknown chracters lke unicode representation.

Our software developes on c#.net and uses MS-access as backend.
When these characters arrives the message cut from there and got stored.

So,I want to know to cause of problem, is it encoding problem or is there any unwanted chracters occures automatically during tansmission.

these characters occures in between words like ignore is word, then these occurs ign ----ore, where --- means some rectangle boxes.

for ex;
Kindly arrange to despatch office
stationary i.e file covers all kind of
envelops etc.
station facing ha----rd.

now when we read there port, mean the actual data transmitted by there software, by using a software it look like this

kindly arrange to despatch office<CR><LF>
stationary i.e file covers all kind of<CR><LF>
enevelops etc.<CR><LF>
station facing ha<194><ETX><STX>D<NULL><STX><NULL><STX>rd.

please tell me what is problem like its related to encoding or ant data conversion from one to another.