OBSAI RF Analyzer Measurement Guide : OBSAI Analyzer
OBSAI Analyzer
Setup Requirements and Checklist
Typical OBSAI Connection
OBSAI Configuration
Link Rate
RP3 Address
LTE Bandwidth
OBSAI Measurement Display
OBSAI Spectrum
OBSAI Configuration Example
OBSAI Analyzer Menu Map
Measurements Menu Map
Sweep Menu
Trace Menus
Limit Menu
Freq Menu
Span Menu
Amplitude Menu
Units of External Gain or Loss
Bandwidth Menu
Measure Menu
OBSAI Config Menu
Display Config Menu
Carrier Trace Config Menu
Carrier Trace Menu
OBSAI Spectrum Menu
Spectrogram Menu
Display Setup Menu
Marker Menu
Marker 2/2 Menu
Sweep Menu
Trace Menu
Trace A Ops Menu
Trace B Ops Menu
Trace C Ops Menu
Limit Menu
Limit Move Menu
Save Menu
Save Location Menu
Recall Menu
The Open Base Station Architecture Initiative (OBSAI) specifications define a set of requirements for a wireless base transceiver station (BTS). Reference Point 3 (RP3) within the OBSAI specifications defines the digital interface between the Base Band Module (BBM) and the Radio Frequency Module (RFM). This is an alternative to the traditional Radio Frequency (RF) coaxial connection, or the CPRI digital interface.
Anritsu’s OBSAI Analyzer (Option 753) allows users to make RF-based measurements over a fiber optic OBSAI link to look for interference problems affecting an RFM. This is accomplished by tapping into the fiber link between the RFM and BBM, using an optical splitter to connect to the Anritsu test instrument. The instrument will decode the OBSAI protocol IQ data and convert it to RF data.
Option 753 requires Option 759, RF over Fiber Hardware. Depending on your Anritsu test instrument model, Option 759 may have a single or dual SFP ports. Refer to your instrument Technical Data Sheet for specifications.
Screen displays vary with the installed option and instrument model being used. The screen captures illustrated in this document are examples and may differ from your instrument display.
The main differences between OBSAI and traditional RF signals are summarized in Table: OBSAI Signal Characteristics (Compared to RF).
OBSAI Signal Characteristics (Compared to RF)
Absolute measurements
Relative measurements
Specific center frequency
Base Band
Absolute power levels
Relative power levels
Full Span capable
Max Span = Carrier BW + 50%
Two types of OBSAI measurements are available:
Spectrum mode is typically used to test the OBSAI link in real time.
Spectrogram mode lets users monitor for intermittent interference over a specifiable recording time.
These OBSAI Analyzer test and measurement functions can be performed from ground level, eliminating the risk and costs of climbing towers. Figure: Connection Configuration for OBSAI Testing with Anritsu Test Instrument illustrates a typical connection configuration for OBSAI testing with an Anritsu test instrument.
Connection Configuration for OBSAI Testing with Anritsu Test Instrument