 Erlang tables are Erlang B and Erlang C. Erlang B assumes that if calls cannot go through then they get dropped (i.e. no queuing possible). Erlang C considers that if a call does not get through then it will wait in a queue. These Erlang tables are good enough for circuit-switched traffic but not for packet switching. We look into the packet switching aspect in later chapters. Erlang B tables are given in Appendix E. It is important for the radio planner to know the capacity that can be offered by the base station equipment, which means that the traffic handling capability of the transceivers takes precedence for capacity planning. Due to modulation, the modulated stream of bits is sent in bursts having a finite duration. These bursts are generally called time slots (TS) in GSM; they have a relatively fixed place in the stream and occur after 0.577 ms. The slots have a width of about 200 kHz. In the GSM system this is known as one time slot. Due to the modulation schemes (i.e. TDMA), there are eight TS at each frequency in each direction. All these eight time slots can be used for sending the traffic or the signalling information. Channel organization within the time slot should be done in such a way that every time a burst is transmitted, it is utilised completely. A typical time-slot composition is shown in Figure 2.13. Signalling requires one time slot (e.g. TSO), and the remaining seven time slots can be used for traffic. In this configuration, the number of subscribers who can talk simultane- ously is seven, on separate traffic channels (TCH). Now, when the number of transceivers increases in the cell, the traffic and signalling channel allocation also change. Generally, Signaling Traffic Channels Channel Figure 2.13 Time slot configuration for single TRX RADIO NETWORK DETAILED PLANNING two transceivers (TRX) would have 15 TCH and one SCH (signalling channel). Four TRX would have 30 TCH and two SCH, which means that the traffic channels increase by 7+8+7+8 for every single increase in the number of transcei