d) GPRS TSL Default(Dynamic) TRX 2 territory GPRS TSL Figure 5.5 GPRS timeslot allocation to CS and PS traffic BCCH and PBCCH). Of the remaining six, three fall under dedicated territory and three under default territory. The TS that are to be used only for the packet data (so cannot be used for the CS traffic) are known as dedicated time slots and fall under dedicated territory. The remaining three TS can be used for both voice and data and fall under default territory. The eight time slots that are used for voice traffic come under the CS territory. Consider a case when all the eight TS in TRX2 are occupied and there is a ninth call; then one TS from the default territory is assigned to this CS traffic. Once the traffic in TRX2 decreases, the call on the default will be switched back to CS territory, leaving the default time slots for possible PS traffic. Power Control Power control in GPRS networks is more complicated because of the addition of the PS traffic. Power control takes place in both the uplink and downlink directions. The uplink power control is used to reduce interference and helps in increasing the battery life of the mobile station. In the downlink direction, the power control feature is used to control the output power of the base station and subsequently help in decreasing the interference in the network. As in a GSM system, the mobile station performs the measurements and, based on these, the output power of the base station is controlled. Temporary Block Flow (TBF) This is a new concept introduced into GPRS networks. The network and mobile establish a connection for data flow. This connection is unidirectional in nature and is maintained for the duration of the call. It is established for the packet data (i.e. blocks) and is not permanent (hence temporary block flow). It can be uplink, downlink or simultaneous uplink and downlink. 5.5.2 The Radio Network Planning Process Both GSM and GPRS have the same radio-wave propagation principles. The one important extra consideration is the addition of