Powerful, accurate and versatile SAASM-based GPS time and frequency receiver

Compliant with Joint Chiefs of Staff SAASM GPS mandate and developed for authorized military users only, Microsemi's XLi SAASM GB-GRAM Time and Frequency Receiver is the world''s most powerful, accurate and versatile Selective Availability Anti-Spoofing Module (SAASM) based GPS time and frequency receiver.



The XLi SAASM's GB-GRAM receiver is a lightweight, third-generation GPS PPS, 12-channel receiver. The internal Ground-Based GPS Receiver Application Module (GB-GRAM) complies with the U.S. Government's GB-GRAM program that fulfills a GPS Directorate initiative to migrate to a defined, open system architecture for ground-based embedded military applications.

Key Features

  • SAASM GB-GRAM PPS GPS Receiver with RAIM
  • Military Signal P(Y) Code SAASM GPS Receiver and Civil Signal C/A-Code GPS Receiver
  • Better than ±20 Nanoseconds RMS Accuracy to UTC
  • Better than 1x10-12 Frequency Accuracy (1 day averaging)
  • Standard 10/100 Base-T Ethernet Network Port with HTML, Telnet, SNMP
  • Enterprise MIB, FTP (for Firmware Upgrades)
  • Hot Start Ready via DAGR/PLGR
  • Standard Vacuum Fluorescent Display and Keypad
  • Completely Modular with Plug-and-Play Capability
  • Numerous Field-Upgradeable, Plug-in Option Cards Available
  • Flash Memory for Remote Software Upgrades
  • IRIG Time Code Generator
  • Standard 1PPS, Selectable Pulse Rate Outputs, Alarm, Auxiliary Reference, and Code In/Out for AM or DC IRIG A, B or NASA 36

Secures Military Communications

The XLi SAASM is designed to generate precision time and frequency signals to synchronize high bandwidth mission critical communications systems that require the highest security support. The XLi SAASM is a Precise Positioning Service (PPS) GPS instrument that authenticates satellite signals (when keyed) with anti-spoofing (A-S) technology.

Supports Black Keys

With the dual frequency XLi SAASM, the P(Y) code is received on both the L1 and L2 bands. The XLi SAASM supports encrypted and unclassified (controlled) Black Keys which can be distributed and loaded electronically. Decryption of the Black Key takes place within the SAASM module. Classified Red keys are also supported.

Offers multiple options

XLi SAASM provides the highest immunity to jamming plus multiple hardware and software options that enable military users to tailor their systems to support nearly every possible output/input needed for time and frequency applications. For example, the N.1 Frequency Synthesizer is a powerful option module that generates pulse rates from 1 to 50 MPPS to drive communication link encryptors.


The XLi SAASM configuration recognition software automatically detects the unit''s setup at power-on providing "plug-and-play" configuration capability for current and future application needs. Many of the XLi SAASM's hardware and software options can be easily upgraded in the field.

Designed for mission critical applications

Easily deployed to generate ultra high precision time and frequency outputs for C4ISR mission critical applications, the XLi SAASM offers a network centric interface with a web page management interface, telnet, and SNMP as standard features with an optional NTP server available. Other standard features and function include: 1 PPS (Pulse Per Second) output; time code In/Out for AM or DC IRIG A, B or NASA 36; programmable rates; alarm open collector; a keypad; RS-232/422 port. Options also available are Time Interval/Event Timing (TI/ET) and Frequency Measurement option.

In compliance with Joint Chiefs of Staff SAASM mandate

Taking into account the Joint Chiefs of Staff mandate that all newly fielded DoD systems using GPS shall use SAASM PPS devices (unless waivered), the XLi SAASM meets present military GPS requirements.

Hot Start Ready

The XLi SAASM provides a port that supports a hot start via a DAGR, PLGR or other PPS device to facilitate direct acquisition of the P(Y) code within hostile environments where the C/A code is unavailable.