l Traffic Load Circuit Switched Traffic Load GPRS Traffic Load 00:00 06:00 12:00 18:00 23:59 Time of Day Figure 2.24 Example traffic profiles hence the number of timeslots in each territory) permits the system to adapt to different load levels and traffic proportions, thus offering optimised performance under a variety of load conditions. Traffic Profile An optimal assignment of the various territory parameters depends on the availability of realistic system traffic profiles. Example traffic profiles for a possible system are shown in Figure 2.24. In this case, distinct peaks in the packet traffic and circuit traffic loads are readily observed, suggesting that long-term territory boundary changes would be likely. These changes would be in addition to short-term changes taking account of fluctuations in the load profile (Figure 2.24). The main parameters of concern in the overall network dimensioning are: peak circuit switched traffic load (Erlangs); peak packet switched load (kbps); circuit switched traffic load during the overall traffic peak hour (Erlangs); packet switched load during the overall traffic peak hour (kbps). The first two parameters give an indication of the limiting optimal resource allocations at the respective peak times (or gross-scale territory boundaries). The latter two will aid the overall dimensioning under peak load conditions, indicating overall carrier requirements. The fact that the respective peaks in traffic load do not necessarily coincide is an important one from the overall dimensioning point of view. Dedicated GPRS Territory It is possible to dedicate traffic channels to the GPRS service if a minimum level of service is required when circuit switched traffic reaches peak levels. If this is done on a system that has been dimensioned for circuit switched traffic at % blocking, then it is clear that the resulting blocking level will increase due to the reduction in the number of channels. Figure 2.25 shows the effect of dedicating GPRS timeslots on circuit switched blocking perform