tl;dr answer
0x7E in binary is ‘01111110’ and it is easy to identify
Answer on Stack Overflow: Why is 0x7E commonly used as Start Delimiter in Communication Protocol?
Also, look at Framing in Wikipedia information about High-Level Data Link Control (HDLC)
Used in:
- XBee – http://knowledge.digi.com/articles/Knowledge_Base_Article/Calculating-the-Checksum-of-an-API-Packet
- PPP – http://www.netfor2.com/ppp.htm
- IP – http://www.netfor2.com/ip.htm
- TinyOS 2.x serial communication – http://www.tinyos.net/tinyos-2.x/doc/html/tep113.html
- XBee – https://books.google.com/books?id=n_BZAgAAQBAJ&pg=PA86&lpg=PA86&dq=7e+start+packet&source=bl&ots=_nMFZRGFJh&sig=RBU83h2I4EJcAYD-_m4ak0b3hlc&hl=en&sa=X&ei=mBdBVYLyIcLAggSr8YGwCQ&ved=0CD0Q6AEwBQ