FPIC Products

The FPIC develops products to address topics and questions concerning interoperable communications, security services, spectrum (related to interoperability), and standards.

Encryption in Land Mobile Radio Systems

Best Practices

• The Who, What, When, Where and Why of Encryption in P25 in Public Safety Land Mobile Radio Systems (.pdf, 1.93 MB) (2023)
  This document provides readers new to the topic of encryption with a discussion of basic issues related to establishing and maintaining effective encryption for Project 25 (P25) interoperable land mobile radio (LMR) communications systems.
• Encryption Key Management Fact Sheet (.pdf, 134.80 KB) (2020) (*)
  This fact sheet educates public safety organizations on how to effectively manage cryptographic keys for their radio systems.
• Operational Best Practices for Encryption Key Management (.pdf, 3.00 MB) (2020) (*)
  This document provides public safety organizations that have chosen to encrypt their radio transmissions with information on how to effectively obtain, distribute, and manage cryptographic keys.

(*) Denotes Archived Material: In an effort to keep CISA.gov current, the archive contains information that may not reflect current policy or programs.

P25 Inter-RF Subsystem Interface (ISSI) and Console Subsystem Interface (CSSI)

Best Practices

Best Practices for Planning and Implementation of P25 Inter-RF Subsystem Interface (ISSI) and Console Subsystem Interface (CSSI) Volume II (.pdf, 596.48 KB) (2020) (*)
This document addresses technology, policy and partnerships for planning and implementing an ISSI or CSSI. The volume includes a best practices checklist intended to prompt practitioners to ask questions and consider strategic elements that may otherwise be overlooked during planning or implementation.

(*) Denotes Archived Material: In an effort to keep CISA.gov current, the archive contains information that may not reflect current policy or programs.

Features and Functions

• The Patching and Dynamic Regrouping: Project 25 Inter-RF Subsystem Interface (ISSI) and Console Subsystem Interface (CSSI) Features and Functions (.pdf, 313.77 KB) (2022)
  This white paper provides technical explanations on how these features work, challenges public safety users have witnessed, and implementation considerations for multi-system environments.
• Emergency Alarm: Project 25 Inter-RF Subsystem Interface (ISSI) and Console Subsystem Interface (CSSI) Features and Functions (.pdf, 1.21 MB) (2021) (*)
  This white paper provides communications system planners, administrators, and technicians with instructive and actionable information about emergency alarms and emergency calls across ISSI and CSSI connections. It provides technical explanations on how these features work, challenges public safety has witnessed, and implementation considerations for multi-system environments.

(*) Denotes Archived Material: In an effort to keep CISA.gov current, the archive contains information that may not reflect current policy or programs.