Digital Signal Processing Reference
In-Depth Information
Figure 15-2.
Packet loss rate as a function of the Gilbert-Elliot model parameter The
value is fixed at 0.6. is set to and to The packet size at
the physical level for the higher and lower rates are 704 and 560 bits respectively. The average
rate transmission has a constant packet size equal to the average size of the adaptive transmission
packets.
the transport protocol layer is:
where N is the maximum number of transmission at MAC (DCF mode) and
is the packet loss rate at physical layer. Consequently, the perceived loss
rate at transport protocol is
In Figure 15-2 the packet loss rate at the transport layer is plotted for differ-
ent packet sizes corresponding to different speech coding rates. Three constant
packet sizes are considered: a 12.2 kb/s speech coding rate the 'higher
rate') with a packet size at the physical layer of 704 bits, a 4.75 kb/s rate
