As the GPRS attached users increase rapidly

the capacity usage ratio is so high that will be beyond the safety threshold now. However

attached users are different from active users

which nearly bring little benefit for operators. Thus

in order to depress the capacity usage ratio

whether increasing the equipment is the only way to extend the SGSN capacity? According to the investigation to live data

this paper describes the relation among SGSN capacity

user model and SGSN internal module in detail. At last

a more reasonable method for SGSN capacity planning is introduced.