Packet data systems are different from voice in that, when enabled, the phone is always connected to the network, even if there is no data flow. System resources are assigned only as needed for the data transfer, and may be shared among many users with real time flow control.

One new packet data system is associated with cdma2000, and is officially called High Rate Packet Data System. At the 3GPP2 standards committee, the name used to describe the system was 1x Evolution Data Only, or 1xEV-DO, a name that has been attached to this system throughout the industry. Base stations are called access networks (AN) in the new specification while mobile stations are called access terminals (AT).

This application note assumes that you are familiar with CDMA technologies and spreading technologies as used in cdma2000. The focus of this paper is on the conformance measurements required by specification C.S0033 version 2.0, which is the Recommended Minimum Performance Standards for cdma2000 High Rate Packet Data Access Terminals, published by 3GPP2. This document is not intended to replace the specification; rather it should be used as a companion volume, helping to explain some of the concepts that may be confusing in the specification itself.

The AT measurements are broken up into three sections: forward link (AN transmits to AT) receiver measurements, reverse link (AT transmits to AN) transmitter measurements, and emissions measurements. Differences between 1xEV-DO technology and the older technologies that can carry both voice and data will be discussed, as well as the measurement challenges associated with this new system. A brief introduction to 1xEV-DO technology will begin the paper.