Base Station Emulation with the Data Channel

Last updated: December 2, 2008

This section is only applicable to the lab applications.

You can use the Data Channel and the test set to emulate a base station. This is particularly useful when you want to have a base station available, for example when demonstrating a wireless application, or when functionally testing wireless devices on a workbench. You may also want to vary key parameters of the cell, such as transmit power, and observe how the DUT performs.

Before you use the Data Channel for Base Station Emulation, you must have the following information:

an IP address valid for the subnet that you will connect the test set to
the valid subnet mask for that subnet
the default gateway for that network
a valid IP address for the DUT

NOTE

There are restrictions regarding IP Addresses that are valid for use. See IP Address Requirements for more information.

A. Hardware Connections

Connect PC to LAN

Please consult with your IT department if you need assistance connecting your PC to the LAN. Refer to Protocol Logging for more information about setting up protocol logging.

Connect Test Set to LAN

Connect the LAN port on the back of the test set to your LAN.

Direct Connection

An alternate connection may be made using the Direct Connection method of connecting to the test set. This may be preferred, since it won't be necessary to characterize the Intranet for the throughput evaluation.

Make the following connections:

Connect the Logging PC directly to the LAN port of the test set using a crossover cable.
When setting up the test set and PCs (see B. Test Set and DUT Setup ), set the IP addresses of the PCs and test set to any valid IP addresses, as long as they are on the appropriate subnets.

Connect DUT to the Test Set

Connect the DUT to the test set.

B. Test Set and DUT Setup

Set Up Test Set

Press the Sys Config key to display the System Config screen.
Use the Instrument Setup softkey ( F1 ) to display the Instrument Setup menu.
Enter the IP address for the test set.
Use the same menu to set the Subnet Mask.
Use the same menu to set the Default Gateway.
Press the Call Setup key to go to the Call Setup screen on the test set.
Select Data Conn Type and set the field to IP Data .
Press the left More key to go to the second screen of the Control menu.
Select DUT PDP Setup to open the DUT PDP Setup menu on the test set.
Set the DUT's IP address (or the address of the controlling PC) in the DUT PDP Setup menu on the test set.
Note: The entered IP address must be on the same subnet as the test set.

Set Up DUT

You may need to set the IP address or other network parameters in the DUT. Set these as needed.
If the device uses a dial-up connection, you may need to set up Dial-Up Networking in the device. Do this as needed.

Base station emulation is ready. You can adjust the cell settings on the test set as desired. Most Cell Parameters require the BCH to be OFF (i.e. Operating mode = Cell Off) before adjusting the settings. Cell Power is an example of a setting that does not require BCH to be OFF. Changing Cell Power, however, or making ARFCN changes would force the DUT to re-camp.

To use Base Station Emulation to transfer data, you must make a data connection with the DUT. See C. Data Connection .

C. Data Connection

The DUT must complete a successful PDP Context activation before datagrams can be transferred. With the test set this involves two steps:

First, the DUT must perform a GPRS attach.

Connect the DUT to the RF IN/OUT port of the test set.
Turn the DUT on and wait for Attached to appear in the Active Cell: field on the test set's front panel display.

For DUTs that don't perform a GPRS attach automatically, you may have to set the DUT to data mode.

Second, the DUT must request a PDP Context Activation.

Use the DUT or the server to initiate transfers. The DUT will request an activation, an IP address will be assigned by the test set, and the PDP Context will be active.
This can be observed by looking for "PDP Active" in the Active Cell Status: field.

You can also perform some measurements while using the Data Channel:

BLER measurements are supported.
TX measurements are supported.
BER measurements are not supported.
Logging is possible during Data Channel operation.

How do You Know When You Have Succeeded?

You have made a successful data connection if you can:

Look at the DUT and verify that the data you were trying to transfer has actually transferred.
See data transfer in both directions by viewing the number of packets transferred in the Counters window of the Call Setup screen on the test set.