Thomas Kunz
Systems and Computer Engineering
14
CDPD: Protocol Stack
–follows
OSI stack
–CDPD
basically specifies physical layer and data link layer
protocols only
–nominal
channel rate: 19.2 kbps, maximum throughput after coding & framing,
ignoring contention, is 11.8 kbps on downlink (to mobile), 13.3 kbps
on uplink
–standard
specifies support for CLNP (ConnectionLess Network Protocol) and IP
(Internet Protocol) at layer 3
–higher
layers can be TCP or TP4
–CDPD
also specifies a wide variety of upper-layer protocols (directory
management, electronic messaging, etc.), based on OSI and
Internet services