UMA/GAN Test System

UMA/GAN Concept

The Unlicensed Mobile Access (UMA) is an extension of GSM/GPRS mobile services into the customer's premises. It is achieved by tunnelling GSM/GPRS protocols through a broadband IP network and an unlicensed radio link in the customer's premises. Additional protocols control and manage the UMA access network, and carry bearer traffic over IP. UMA is therefore a complement to traditional GSM/GPRS radio coverage - used to enhance customer premises coverage, increase network capacity and potentially lower costs.

The first UMA specifications were published in September 2004 (R1.0.0). After the initial release, the UMA specifications were contributed to the 3GPP organization as part of 3GPP work item "Generic Access to A/Gb interfaces". On 8th April 2005, the 3GPP approved specifications for Generic Access to A/Gb interfaces for inclusion in 3GPP Release 6 (3GPP TS 43.318). There were only trivial terminology changes made to the UMA protocol and architecture specifications during the transition to 3GPP.

Under 3GPP, what was previously known as UMA is now instead referred to as Generic Access Network or GAN and the UMA Network Controller (UNC) entity is instead referred to as a Generic Access Network Controller or GANC.

The following figure gives the functional architecture of a Generic Access Network.

Two new entities are introduced by the GAN architecture:

• UMA/GAN-enabled and dual-mode mobile station. The mobile station must be able to run procedures that detect when the user is roaming in and out of a Bluetooth or Wi-Fi network so that it can switch to and from UTRAN mode.
• Generic Access Network Controller (GANC). The GANC is equivalent in function to a Base Station Controller in a typical UTRAN network; unlike a BSC however, the front end of the GANC connects to the MS via an IP access network. The GANC essentially acts as a bridge between the Bluetooth/Wi-Fi and cellular network. The GANC also includes a Security Gateway (SEGW) that terminates secure remote access tunnels for the mobile station, providing mutual authentication, encryption and data integrity for signalling, voice and data traffic.

UMA/GAN Typical Test Configuration

The figure above provides a pictorial overview of the system, the premise of which is to provide integrated lab based emulation of both a UTRAN cell and a GAN "cell" for use by a connected MS. The system is designed to allow a connected MS to make either UTRAN or GAN based voice, data and signaling connections as well as to exercise all applicable GAN <-> UTRAN mode transitions. The system achieves this aim through simulation or inclusion of all real-world network components that are required for such procedures.

The UMA/GAN test system is comprised of the following components:

• A test set running E6703E Lab Application Firmware.

  The system is built around the test set's existing capabilities to provide UTRAN cell and core mobile network emulation. All existing controls at the test set to configure its UTRAN cell and control core PLMN operation (voice call initiation, SMS, data routing etc.) remain available for use within the system as per their existing behavior in the test set.

• One or more commercial or proprietary WLAN or Bluetooth access point.

  There are no changes required to off-the-shelf wireless access points for use in UMA/GAN, the only recommendations are that for voice operation and battery life optimization; access points that support QoS features are likely to exhibit better performance.

• Zero or more commercial or proprietary SEGWs and AAA servers.
• A standard PC running proprietary Keysight GANC software.

  To aid in simulation of the GAN `cell' in the system, Keysight provide proprietary test focused GANC emulation software for use with the system. This software is capable of communicating with a connected MS using the standardized GAN Up interface protocols, namely GA-RC, GA-CSR, and GA-PSR. The Keysight GANC also connects the test set in the system to make use of its core network capabilities via the same BSSAP & BSSGP protocols that are designed for this purpose in a real network (although these are run over a proprietary IP connection in the system rather than SS7 as would normally be used). The combination of these interfaces at the GANC allow a connected MS to fully make use of the GANC for accessing the test set's core network to perform GAN based speech, data and signaling procedures.

• Any number of further networked devices (typically PCs) running network servers such as FTP, HTTP, MMSC etc. for use in end to end GAN data throughput and application test of the handset, and
• A dual-mode GAN enabled handset.

Note: Only the test set, its associated firmware and the GANC application software in such a system are supplied by Keysight. All other components must be supplied and configured independently by yourself.

UMA/GAN related procedures

The procedures supported in the UMA/GAN Test System include:

• GAN discovery and registration procedures
• MO and MT voice calls over GAN
• MO and MT Circuit Switched SMS support over GAN
• GAN Rove-in / Rove-out procedures
• Network initiated voice handover from UTRAN to GAN (Handover-in)
• MS/GANC initiated voice handover from GAN to UTRAN (Handover-out)
• Network initiated voice handover from GAN to UTRAN
• View MS reports sent to GANC
• View current MS GAN status
• GAN protocol logging via Ethereal (a free third party software), cellular signaling and traffic logging via WPA.

See UMA/GAN Procedures Ladder Diagrams for the message sequence chart of UMA/GAN related procedures.

Refer to the user guide of GAN Controller (E6962A) for details on how to perform the above test procedures.

UMA/GAN Parameters

• Access Stratum reporting

  This parameter is used to report the current access stratum in use by a connected mobile station. This is the only parameters on the test set side.

  The GPIB command to set this parameter is CALL:ACCess:STRatum? .

• GANC configuration and report parameters.

  Refer to the user guide of GAN Controller (E6962A).

Operating Considerations

The existing data throughput monitor at the test set can be used in the UMA/GAN test system to monitor data connections made by the MS over both GAN and UTRAN access stratums.

The Wireless Protocol Analyzer can log the UTRAN signaling and traffic protocols. For GAN logging, you can choose Wireshark (formerly known as Ethreal). Wireshark is a free network protocol analyzer widely used throughout the communications and IT industry. Wireshark provides very good support for logging all GAN signaling and user data messages sent between the MS and GANC and also does a pretty good job of decoding any embedded UTRAN core network destined messages contained within them.

Transmitter and Receiver Measurements are available at all times at the test set in the test system as per existing test set's behavior. However, the measurement results are only available at the test set when the MS is operating in UTRAN mode as otherwise there is no RF channel available to measure.

Related Topics

How to use the UMA/GAN Features

UMA/GAN Procedures Ladder Diagrams

CALL:ACCess