User's Manual Part 1

Nomad User’s Manual Chapter 4 – Specifying Nomad Settings

4.2 Specifying GPS/Time Settings

Specify settings related to time synchronization and GPS on the GPS/Time tab. The Automatic

Time Synchronization and GPS areas are discussed in detail below.

Figure 4-3 - GPS/Time Settings

4.2.1 Time Synchronization

The successful use of the Nomad system is strictly dependent on consistent timing between the test

laptop and the Audio or Call Server. Time synchronization is critical in the case of a Voice Quality or

Mobile Terminated Call Performance campaign. To specify time synchronization options:

 Select the time synchronization Source. The time synchronization source is used as the

method of automatic time synchronization and the first method attempted in the initial time

synchronization performed prior to testing.

o Internet Time Server – Nomad will synchronize the PC’s clock to internet time on

demand. In order to use this method, you must have a dedicated internet

connection.

 Note: Spirent does not recommend using this method for Voice Quality

testing performed while drive testing. Substantial latency may be

introduced when the internet time protocol operates in a mobile

environment. If possible, use GPS synchronization in this case.

o GPS – Nomad will synchronize to the appropriate server using GPS time. Spirent

recommends using this time synchronization method when GPS is available,

particularly in the case of Voice Quality tests performed while drive testing.