Technology Platforms

The migration path that an operator must or should make from an exiting
2G to a 3G wireless platform needs to be chosen with extreme care to
ensure the best allocation of the company’s resources, including capital,
spectrum, and manpower. In order to determine the best utilization of
resources, the choice of which 3G platform to use needs to be decided upon.
The decision as to which platform to choose is often, and correctly, based on
the existing system that is in place. However, which 3G platform to use does
not necessarily need to be dictated based on the existing 2G platform. The
2.5 platform will in all cases require some change to the existing infrastructure.
The commonality for the 3G systems decided upon is the packet
data network that the operator will need to deploy, and this will need to be
done regardless of which platform is chosen. Therefore, the migration strategy
is really directly related to the radio frequency network that is in place
or will be in place.
Several access platforms are referred to as 2.5G. The objective for a 2.5G
platform is to bridge an existing network that is using 1G or 2G radio
access platforms to that of 3G. The obvious question is, “why not transition
to 3G right from 1G or 2G?” The brutal reality is that 3G systems are not
currently deployed or even really available at this writing; however, a vast array of 2.5G platforms are available that can deliver many of the required
data rates envisioned for 3G services.
The general platforms that will be briefly discussed are as follows:
■ EDGE/GPRS
■ High-Speed-Circuit Switched Data (HSCSD)
■ CDMA2000
In order to make an informed decision as to which interim platform to
utilize, fundamental knowledge of the interim platforms needs to be understood.
Therefore, what follows is an overview of several major technology
platforms that are referenced as 2.5G.