System Planning

We have considered some of the factors determining Node B RF power and downlink
quality (for example, linearity) and Node B receive sensitivity (uplink quality). We
now need to consider some of the system-level aspects of system planning in a 3G
network.
Many excellent books on system planning are available. Several have been published
by Wiley and are referenced in Table 11.8.
Our purpose in this chapter is to put simulation and planning into some kind of
historical perspective. Why is it that simulations always seem to suggest that a new
technology will work rather better than it actually does in practice? Why is it that initial
link budget projections always seem to end up being rather overoptimistic.
Cellular technologies have a 15-year maturation cycles. Analog cellular technologies
were introduced in the 1980s and didn’t work very well for five years (the pain phase).
From the mid-1980s onward, analog cellular phones worked rather well, and by 1992
(when GSM was introduced), the ETACS networks in the United Kingdom and AMPS
networks in the United States and Asia were delivering good-quality consistent voice
services with quite acceptable coverage. The mid-1980s to early 1990s were the pleasure
phase for analog. In the early 1990s there were proposals to upgrade ETACS in the
United Kingdom (ETACS 2) with additional signaling bandwidth to improve handover
performance. In the United States, narrowband (10 kHz channel spacing) AMPS
was introduced to deliver capacity gain. However, the technology started running out
of improvement potential, and engineers got bored with working on it. We describe
this as the perfection phase.
When GSM was introduced in 1992, it really didn’t work very well. Voice quality
was, if anything, inferior to the analog phones and coverage was poor. The next five
years were the pain phase. GSM did not start to deliver consistent good-quality voice
service until certainly 1995 and arguably 1997.

The same is happening with 3G. Networks being implemented today (2002 to 2003)
will not deliver good, consistent video quality until at least 2005 and probably not until
2007. By that time, 2G technologies (GSM US TDMA) will be fading in terms of their
further development potential, and a rapid adoption shift will occur.
Let’s look at this process in more detail.