<s>
Important	O
aspects	O
of	O
cellular	B-Protocol
traffic	I-Protocol
include	O
:	O
quality	B-General_Concept
of	I-General_Concept
service	I-General_Concept
targets	O
,	O
traffic	O
capacity	O
and	O
cell	O
size	O
,	O
spectral	B-Protocol
efficiency	I-Protocol
and	O
sectorization	O
,	O
traffic	O
capacity	O
versus	O
coverage	O
,	O
and	O
channel	O
holding	O
time	O
analysis	O
.	O
</s>
<s>
Teletraffic	O
engineering	O
in	O
telecommunications	O
network	O
planning	O
ensures	O
that	O
network	O
costs	O
are	O
minimised	O
without	O
compromising	O
the	O
quality	B-General_Concept
of	I-General_Concept
service	I-General_Concept
(	O
QoS	O
)	O
delivered	O
to	O
the	O
user	O
of	O
the	O
network	O
.	O
</s>
<s>
At	O
the	O
time	O
that	O
the	O
cells	O
of	O
a	O
radio	O
subsystem	O
are	O
designed	O
,	O
Quality	B-General_Concept
of	I-General_Concept
Service	I-General_Concept
(	O
QoS	O
)	O
targets	O
are	O
set	O
,	O
for	O
:	O
traffic	O
congestion	O
and	O
blocking	O
,	O
dominant	O
coverage	O
area	O
,	O
C/I	O
,	O
outage	O
probability	O
,	O
handover	B-Protocol
failure	O
rate	O
,	O
overall	O
call	O
success	O
rate	O
,	O
data	O
rate	O
,	O
delay	O
,	O
etc	O
.	O
</s>
<s>
used	O
effectively	O
to	O
ensure	O
that	O
all	O
users	O
receive	O
service	O
,	O
that	O
is	O
,	O
the	O
quality	B-General_Concept
of	I-General_Concept
service	I-General_Concept
is	O
consistently	O
maintained	O
.	O
</s>
<s>
Cellular	O
systems	O
use	O
one	O
or	O
more	O
of	O
four	O
different	O
techniques	O
of	O
access	O
(	O
TDMA	O
,	O
FDMA	O
,	O
CDMA	B-Protocol
,	O
SDMA	O
)	O
.	O
</s>
<s>
CDMA	B-Protocol
cellular	O
systems	O
can	O
allow	O
an	O
increase	O
in	O
traffic	O
capacity	O
at	O
the	O
expense	O
of	O
the	O
quality	B-General_Concept
of	I-General_Concept
service	I-General_Concept
.	O
</s>
<s>
Important	O
parameters	O
like	O
the	O
carrier-to-interference	O
ratio	O
(	O
C/I	O
)	O
,	O
spectral	B-Protocol
efficiency	I-Protocol
and	O
reuse	O
distance	O
determine	O
the	O
quality	B-General_Concept
of	I-General_Concept
service	I-General_Concept
of	O
a	O
cellular	O
network	O
.	O
</s>
<s>
Channel	O
Holding	O
Time	O
is	O
another	O
parameter	O
that	O
can	O
affect	O
the	O
quality	B-General_Concept
of	I-General_Concept
service	I-General_Concept
in	O
a	O
cellular	O
network	O
,	O
hence	O
it	O
is	O
considered	O
when	O
planning	O
the	O
network	O
.	O
</s>
<s>
as	O
handover	B-Protocol
will	O
take	O
place	O
and	O
the	O
MS	O
relinquishes	O
the	O
channel	O
.	O
</s>
<s>
One	O
of	O
the	O
papers	O
in	O
Key	O
and	O
Smith	O
defines	O
channel	O
holding	O
time	O
as	O
being	O
equal	O
to	O
the	O
average	O
holding	O
time	O
divided	O
by	O
the	O
average	O
number	O
of	O
handovers	B-Protocol
per	O
call	O
plus	O
one	O
.	O
</s>
