added more glossary entries

docs/glossary.rst

@@ -8,3 +8,18 @@ Glossary
 
    FEC
       Forward Error Correction
+
+   Frame
+      The individual components of a stream, each of which contains payload data interleaved with frame signalling.
+
+   Link Information Frame
+      The first frame of any transmission. It contains full LICH data.
+
+   LICH
+	  Link Information Channel. The LICH contains all information needed to establish an M17 link. The first frame of a transmission contains full LICH data, and subsequent frames each contain one sixth of the LICH data so that late-joiners can obtain the LICH.
+	  
+   Packet
+      A single burst of transmitted data containing 100s to 1000s of bytes, after which the physical layer stops sending data.
+   
+   Superframe
+      A set of six consecutive frames which collectively contain full LICH data are grouped into a superframe.