Anritsu Remote Spectrum Monitor MS27201A

Overview

Demand for access to the RF spectrum continues to grow at an increasing pace. Alongside new cellular bands, the use of RF spectrum by satellite operators, microwave links, radar, and defense electronics expands each year. Efficient and effective use of the spectrum by users requires a deep insight into the total radio frequency activity by other users in region. The Remote Spectrum Monitor MS27201A is designed to facilitate wide area spectrum monitoring up to 9 kHz to 54 GHz. Building on over 40 years of experience in developing high performance field portable spectrum analyzers, the Remote Spectrum Monitor MS27201A series is Anritsu's highest frequency spectrum monitor covering all standard LMR, cellular, satellite, and defense electronic bands.

The Remote Spectrum Monitor MS27201A is available with 9 kHz to 54 GHz frequency range options.

Key Specifications

Key Features

• Control Interfaces: Ethernet
• PC Control: Anritsu Remote and Report Tools (ARRT)
• Automated Monitoring Software: MX280001A Vision monitor PC application
• IQ: Capture and streaming IQ data through Ethernet, USB, and PCIe interfaces
• Channel Scanner: Horizontal bar chart, strip chart and mapping mode with channels up to 60
• Cellular Measurements: WCDMA, 5GNR FR1, and LTE FDD/TDD transmitter measurement suites
• Continuous Operation and Recovery: Built-in watchdog timer and auto recover on power failure provide continuity of service
• Traces: Six with independent detectors per trace
• Markers and Limits: 12 Intelligent markers and comprehensive limits
• Event Capture: Save traces and alarms on defined events

Designed for Long Term Monitoring Applications

Compact Rack Mount Format

The Remote Spectrum Monitor MS27201A instruments are standard 19-inch rack wide and 2U tall. They are designed to slot directly into test system racks using minimal space. The instruments are powered from a supplied 75 Watt power block that minimizes rack temperature gain.

High Performance

Typical applications for the Remote Spectrum Monitor MS27201A require excellent noise floor for signal detection and high TOI to minimize internal distortions when the input is exposed to multiple input signals. With a displayed average noise level (DANL) of –164 dBm and a TOI of typically +20 dBm, signal detection, and measurement integrity are assured. Measurement bandwidths of up to 110 MHz with IQ capture and streaming options provide class-leading functionality in a small form factor package.

24/7 Operation

The Remote Spectrum Monitor MS27102A is designed for continuous operation. Recovery features are included to ensure reliable and uninterrupted monitoring. A built-in watchdog timer resets the instrument in the event of a software interruption. Should a break in the power supply occur, when the power is restored the instrument will resume normal operation in the same state it was in prior to loss of power.

IQ Capture and Streaming

The Remote Spectrum Monitor MS27201A provides for the capture of IQ data of Signals-of-Interest (SOI) for later post-processing. When an illicit signal is detected, post-capture analysis is performed to identify the source of the signal. The 150 MHz (per Option 105) measurement bandwidth enables the capture of transient and continuous signals to internal instrument memory or directly to a mass storage device. Dedicated PCI interfaces provide the bandwidth required for the most demanding cases where real-time streaming is required.

Optional vector signal analysis software MX280005A performs modulation analysis on common digital modulation standards for greater insights.

With the accessory data converter module MA25424A, IQ data can be streamed to the X-COM IQC5000B for mass storage and later analysis with X-COM SpectroX software.

Diagram Description: An illustration shows the MS27201A unit connected via a PCI interface to a computer, labeled "MS27201A Streams IQ Data Directly to the X-COM IQC5000B Record and Playback System." Another image shows a "PCI Streaming Kit."

5GNR and LTE Modulation Quality Measurements

Options for 5G and LTE demodulations enable detailed analysis of these common cellular standards. Measurements include base station PCI and bandwidth, as well as frequency, to facilitate the identification of rogue or illicit transmitters. Coupled with the spectrogram and IQ capture, field technicians have an array of tools to capture and analyze signals in the cellular spectrum.

Distributed Spectrum Monitors with Centralized Control

Connect multiple Remote Spectrum Monitor MS27201A instruments to a network and control them from a single centralized PC.

Diagram Description: A network diagram shows a single PC connected via Ethernet to multiple Anritsu MS27201A units, illustrating centralized control.

Applications

Spectrum Clearing

Frequency spectrum is typically allocated and policed by a national regulator. Licenses for specific blocks of spectrum are time-limited and can change their use as new technologies and applications evolve. When a new license is issued, the new spectrum owner needs to survey the spectrum to confirm legacy users have ceased transmitting. As transmitters may only be active periodically, monitoring the spectrum for a period of days or weeks may be necessary to ensure all legacy users have moved out of the spectrum.

The Vision software option has integrated tools to simplify this spectrum clearing process.

Diagram Description: An illustration depicts a Broadcast TV Satellite operating on C-Band, and several New 5GNR gNBs in C-Band, with radiating signals. The text below reads "MS27201A Monitoring for Adjacent Channel Interference from New Cellular Base Stations with Legacy Satellite Downlinks."

Shared Spectrum Monitoring

It is becoming increasingly common for more than one technology to be allocated access to the same block of spectrum. Early examples of spectrum sharing include the 3.5 GHz band in the USA where legacy military radars and new commercial cellular networks share the same spectrum. A tiered access regulation manages their co-existence. In order for operators to understand how this will affect their long-term ability to provide a service, they need to continuously monitor activity in the spectrum to build up an understanding of likely availability over days and months.

The Remote Spectrum Monitor MS27201A with MX280001A Vision software or custom monitoring applications enables spectrum owners to build up maps of how the spectrum is being used and what access they can expect, depending on their status in any tiered system.

Diagram Description: An illustration shows a seascape with Naval Vessels and Military Radar on the water, and cellular base stations on land, all sharing the same spectrum. The text below reads "Military Radar and Commercial Communications Systems often Share the Same Spectrum with Priority Access."

Satellite Ground Station Monitoring

The expansion of satellite services is growing rapidly. Satellites have become ubiquitous providers of communications systems and monitoring of multiple properties of the earth, including weather, light pollution, and heat sources. The proliferation of low earth orbit communications networks and GNSS positioning systems has resulted in forecasts of thousands of satellites orbiting the earth.

Satellite downlink signals typically arrive at the surface of the earth with very low signal level, and the latest generation of satellites are starting to use millimeter-wave (mmWave) frequencies for these downlinks, including 8 to 9 GHz X band for space research, 12 GHz Ku band for domestic TV broadcast, and 23 to 27 GHz for fixed link broadcasts.

The sensitivity of satellite downlink receivers makes them very susceptible to interfering signals. Continuous monitoring of the in-band and adjacent frequencies is essential to maintain robust communications and understand if and when additional filtering may be required.

At earth stations with multiple dishes, Remote Spectrum Monitor MS27201A instruments can be located at the base of the dish to monitor activity across the site in real time. A single monitor showing the spectrum at each receiver provides a dashboard that alerts operators of potential interference, giving the earliest possible warning of potential communications failure.

Diagram Description: An illustration shows multiple satellite dishes at an earth station connected to a Control Center, with signals being monitored. The text below reads "Monitor the Downlink Spectrum from Multiple Ground Stations with a Single PC in the Control Room."

Critical Site Security

Many government defense and commercial sites have experienced aggressive and intentional interference from hostile agents. On-site communications are critical for the smooth running of large sites with many interdependent automated systems. Monitoring and early detection of hostile transmissions is essential to effective site operation. Examples of vulnerable sites include classified buildings, transport hubs, and government offices.

Positioning MS27201A spectrum monitors across a site with broadband spectrum coverage gives the best possible security against such attacks. The measurements from all deployed instruments are routed back to a common control room, facilitating monitoring and rapid detection of interfering signals at any location across a site.

Diagram Description: An isometric view of a facility shows multiple MS27201A units deployed in-place, a laptop, a directional antenna, and a hidden transmitter. A roaming MS2090A is also shown. The text below reads "Combination of RSM and HH SPA to Help Identify Hidden Transmitters."

Interference Monitoring

Major sporting events, festivals, and conferences bring together multiple agencies to a single location for maybe only a few days or weeks. Each contributing agency often has unique communications and telematics requirements that require temporary licensing. Typical examples include international motor racing events, football tournaments, and global music festivals. To ensure all the stakeholders' systems are transmitting on their approved frequencies and not interfering requires strict monitoring of the spectrum.

Remote spectrum monitoring MS27201A instruments cover all the frequency allocations that are active at such events, such as telematics links, radio microphones, satellite news gathering, and broadcast point-to-point radio links.

Regulatory Enforcement

National regulators need to police spectrum activity in large urban areas. Large cities will have multiple licensed transmitters, and unless the spectrum is policed, there will be interference and degraded performance across all systems.

Instrument Control Options

Remote Spectrum Monitor MS27201A PC Anritsu Remote and Report Tools (ARRT)

The Remote Spectrum Monitor MS27201A can be controlled using customer-written PC Anritsu Remote and Report Tools (ARRT), a downloadable PC Graphical User Interface (GUI), or with the MX280001A Vision Monitor PC software application.

The MS27201A PC ARRT Software provides an off-the-shelf GUI for common applications. A downloadable PC application provides a comprehensive user interface. Connect to any Remote Spectrum Monitor MS27201A on the same network to take manual control of the instrument, configure measurements, and save results. No special user training is required as the PC GUI is based on the standard Anritsu spectrum analyzer interface. Traces and IQ data are stored directly to the PC memory for ease of later recall and playback functionality. Full screen captures can be saved, as well as individual result traces, traces saved by "Save on Event" triggers, or traces continuously saved over a defined period of time.

The Remote Spectrum Monitor MS27201A instrument's ARRT Software is ideal for manual configuration and viewing of spectrums when continuous monitoring is not required. All the standard features of a spectrum analyzer are available to capture specific events and save images or trace files directly to the PC memory. Manual real-time configuration of the spectrum monitor allows targeted configurations for detailed signal analysis and investigation.

Diagram Description: An image shows an Anritsu MS27201A unit connected via Ethernet cable to a PC running the ARRT software, with a spectrum analyzer display on the PC screen.

Remote Spectrum Monitor MX280001A Vision Monitor Software Application

When long-term monitoring is required, the optional Vision software offers a full suite of spectrum monitoring and trace archiving options.

Vision Monitor software offers a range of applications for monitoring the RF spectrum over a period of time and storing results to a database. Vision Monitor is an ideal tool for long-term interference monitoring. Limits can be set with automated alarms for limit violations to capture short-term or intermittent signals. Other features include a scanner option that enables the monitoring of a range of frequency bands or channels over time with unique settings for each channel being monitored. A multi-trace view shows the spectrum for all channels being monitored on the same display.

The Vision Monitor application is fully automated. Measurements can be captured and periodically uploaded to a database for further processing. Depending on need and storage capacity, users can store spectrum history over many months or years with a user-defined capture assigned schedule.

All spectrum measurement databases are searchable, allowing the user to quickly locate patterns of signal activity relevant to an investigation. The spectrum history can also potentially be used in legal proceedings for documenting illegal or unlicensed broadcast activity. Other functions provided by Vision Monitor include:

• Threshold and trace mask settings for alarm generation
• Email alert sent when threshold violation generates an alarm
• Reporting on spectrum integrity on a daily or weekly basis
• Vision runs on a PC/laptop using the Windows® operating system (Windows 10/11)
• Option 401 (enable Vision Locate)

Diagram Description: Two screenshots are shown: one displaying spectrum traces from multiple MS27201A units on a single PC monitor, and another logging spectrum traces for extended time periods with alarms.

Advanced Measurement Options

Real-Time Spectrum Analyzer (Option 199)

For many spectrum and network stakeholders, basic spectrum sweeps may not give enough information. The RTSA option provides real-time signal capture with 110 MHz bandwidth and the ability to capture signals down to a 2.05 µs duration with 100% POI at full amplitude. This provides unrivaled insight into interference in the wireless spectrum, capturing interfering signals that are too short in duration to be seen with conventional spectrum analyzers yet may be degrading system performance. A power spectral density display shows the relative time that RF power is present at all levels and frequencies within the capture span. This is a powerful tool to find interfering signals within the same band as known/wanted signals. The spectrogram displays the maximum output of the RTSA fast Fourier transform (FFT) over time with settable 50 ms to five seconds resolution. The spectrogram provides a history of spectral activity enabling intermittent interferers to be detected and recorded.

Diagram Description: A screenshot of the RTSA spectrogram display, showing signal density over time.

Pulse Radar Measurements

The wide bandwidth enables detailed analysis of pulsed radar signals. In zero span, the default bandwidth is 40 MHz and the minimum sweep time is 60 ns, with pulse rise time measurements as short as 20 ns. Up to 12 markers can be positioned on the traces to simplify pulse repetition, pulse width, and rise time measurements. In zero span, a fixed frequency IF output option is also available to interface with external analysis tools. To get fully automated pulse characterization with measurements made in compliance with IEEE Std 181-2011, section 5.2.1, add pulse analyzer Option 421.

LTE Base Station Analyzer (Option 883)

The Remote Spectrum Monitor MS27201A features several measurements for installation and maintenance of LTE, FDD, and TDD radios. The goal of these measurements is to help maximize data rate and capacity with accurate power settings, ensuring low out-of-channel emissions and good signal quality. These attributes help to create a low dropped or blocked call rate, and a good customer experience. LTE sites also play a critical role in most early 5G deployments, acting as the anchor to 5G communications. Cell site technicians or RF engineers can make measurements OTA to spot-check a transmitter's coverage and signal quality without taking the cell site off-line. When the OTA test results are ambiguous, the user can directly connect the device to the base station to check the signal quality and transmitter power.

The Remote Spectrum Monitor MS27201A offers the following LTE measurements:

• Cell ID, Sector ID, Cell Group
• Frequency Error
• Time Offset
• PBCH, RS, and SS Power
• Signal Quality (EVM)
• PBCH
• PDSCH (QPSK, 16QAM, 64QAM, 256QAM)
• MIMO Antenna Power and Time Alignment Error (TAE)
• Adjacent Channel Power (ACP)
• Spectral Emissions Mask (SEM)
• Channel Power
• UL/DL Interference
• Channel Spectrum
• Time Alignment Error
• Resource Block Usage
• OFDM Symbol Transmit Power (OSTP)
• Carrier Aggregation
• Multi-PCI Scanner
• Control Channel Measurements
• Constellation Diagrams for PBCH and PDSCH (up to 256QAM)

Diagram Description: A screenshot of the LTE Results Summary Display, showing various LTE measurement parameters.

5G NR Base Station Measurements (Option 888)

The rapid introduction of 5G NR networks requires an instrument that can validate the performance of the gNB base stations quickly in a field environment. In both the 3.5 GHz and (mmWave) 28/39 GHz bands, the adoption of active antenna systems means that new test methods need to be considered. Some radios may have test monitor ports integrated, but many operators will make gNB transmitter measurements OTA.

The Remote Spectrum Monitor MS27201A high-performance spectrum analyzer performs the essential measurements in full compliance with the 3GPP TS 38.104 V15. Measurements supported include:

• PCI Cell/Sector ID
• Frequency Error
• Time Offset
• Difference in Time Offset
• Modulation Quality (EVM)
• PBCH Constellation
• SS-RSRP/RSRQ/SINR/RSSI
• Channel Power
• Occupied Bandwidth
• Adjacent Channel Leakage Ratio
• Transmitter Spurious
• Carrier Aggregation
• OTA Multi PCI Scanner
• EIRP
• TDD Uplink Interference with Gated Spectrum
• Spectral Emissions Mask (SEM)
• SIB Decoding of MCC and MNC

A key part of 5G NR signals is the synchronization signal block (SSB). Decoding the SSB can reveal the important cell characteristics, like cell ID, frequency error, and beam powers. Making measurements on the SSB allows transmitter testing on a live gNB. As well as displaying beam ID, the RSRP is graphed for each of the beams in the SSB. In order to properly decode the signal, the user must know the center frequency, bandwidth, and subcarrier spacing of the signal under test. This can be entered manually or by using a 3GPP-defined band and absolute radio-frequency channel number (ARFCN). It is also critical to know the frequency position of the SSB relative to the center frequency of the signal. This can also be entered manually as an offset from center or by entering the global synchronization channel number (GSCN). In cases where the SSB location is unknown, the Remote Spectrum Monitor MS27201A has an Auto SSB Detect feature that searches the 3GPP-defined raster of potential SSB positions to find it automatically. In some cases, especially in mmWave, a single transmitter can be transmitting up to eight carriers simultaneously. The Remote Spectrum Monitor MS27201A has a carrier aggregation feature that allows up to eight individual carriers to be set up and measured sequentially in a loop to ensure all are working correctly.

Diagram Description: An illustration shows a 5G NR frame structure with synchronization signal blocks (SSB) and a 5G Radio tower with a directional antenna. The text below reads "Remote Spectrum Monitor MS27201A Displays RSRP vs Beam Index Based on OTA Analysis of the 5G NR SSB."

Remote Spectrum Monitor MS27201A Interfaces

The Remote Spectrum Monitor MS27201A comes standard with: 2 x USB 3.0 type A host ports and a high-speed Data Out port. USB ports provide for saving of screen images as a .png, saving IQ data files, IQ data streaming, and facilitate software or option updates. The Data Out port is used for high-speed IQ streaming. Integrated rack mount flanges on the case simplify installation into standard 19-inch rack systems, and the low power consumption and air cooling allow for integration immediately adjacent to other instruments, maximizing space efficiency.

Diagram Description (Front Panel): The front panel features several connectors and indicators: IF Out, RF In Port (with warnings: Max Input +23 dBm, 50 VDC; +10 dBm Preamp; Avoid Static Discharge), Ref In, Ref Out, Trigger In/Out, Bias Voltage (0 to +5 VDC max, +500 mA max), GPS, USB 3.0 Interface (Type A), and Data Out Port. A Status Indicator light is also present.

Diagram Description (Rear Panel): The rear panel shows an External Power Connection, LAN Connection, Service Port, Security Lock, and Cooling Fan. Warnings about static discharge and internal servicing are also visible.

Ordering Information

For a full list of all accessories for the Remote Spectrum Monitor MS27201A, please refer to the Technical Data Sheet (P/N 11410-02833).