Lawful interception of voice by law enforcement agencies (LEAs) harkens back to a time when unencrypted phone calls over a wireline carrier network defined electronic communication. In the smartphone era, other methods have proliferated, including a universe of over-the-top communication channels such as WhatsApp and Telegram alongside social media and user-generated video including TikTok and Reels. Moreover, those communications are generally encrypted. While tools like SS8’s E-PXE help investigators gain insights from them by capturing their associated metadata, lawful interception has largely shifted its focus from intercepted communications content (CC) to call data records (CDRs) and other signaling data, as well as location intelligence.
Alongside the collection and interpretation of such breadcrumbs, however, monitoring centers (MCs) still handle large amounts of audio directly. While most encrypted content is beyond LEAs’ reach, mechanisms exist to decrypt some calls. Depending on the jurisdiction, communication service providers (CSPs) may be legally required to provide encryption keys or implement backdoors that allow access with proper legal authorization. Key escrow is also possible, where encryption keys are stored with a trusted third party, known as a key escrow agent, for retrieval when authorized.
When unencrypted voice audio is available, its value is often limited by poor call quality (including background noise) that interferes with insights. Continual improvement in carrier technologies keeps making audio quality better with new developments such as Voice over LTE (VoLTE) and Voice over 5G New Radio (Vo5G or VoNR) as well as new and improved audio codecs. At the same time, the SS8 platform offers expanded tools and capabilities to improve analysis in the MC, including deeper analysis and better integrating voice CC into lawful intelligence more broadly.
Network Voice Changes and Lawful Intelligence Implications
Voice services were originally offered on circuit-switched analog networks, which were replaced by packet-switched transmission beginning with 2G, on the path to digitalization that also included proliferation of VoIP from 4G forward. Initially, 4G networks transmitted voice calls by transmitting them over the 2G or 3G network. The implementation of VoLTE services allows direct transmission of voice calls over the 4G LTE network using packet-switched technology, dramatically improving quality and latency. Similarly, 5G networks first used 4G technology to transmit voice, which is now being replaced with VoNR to directly use the 5G stand-alone (SA) network for higher quality and reliability.
Codec evolution also plays a significant role. Still widely used in landline and Voice over IP (VoIP) services, G.711 is an older codec that provides uncompressed, high-quality audio. The G.722 codec builds on G.711 using wideband coding that offers richer sounding voice and variable data rates. With better compression, G.729 is more bandwidth-efficient than predecessors, albeit with some quality loss due to a narrower frequency range. Ongoing improvements include the Internet Low Bitrate Codec (iLBC), which is widely used for IP voice traffic, and Opus, which is used primarily in the open source community.
From the lawful interception perspective, improvements to call fidelity create better audio patterns that benefit analysts. Older approaches presented only a single waveform that combined all parties on the call as well as background noise. VoLTE and 5GNR allow the creation of separate waveforms for each target of interest as well as spatial audio, both of which provide richer information for more advanced voice analytics.
Next-Generation Audio Processing on the SS8 Platform
The SS8 platform integrates a voice player into the lawful intelligence environment. In addition to standard abilities such as volume and playback speed, a built-in graphic equalizer provides the ability to control volume levels of individual waveforms or audio frequencies within intercepted audio. It can easily change the relative levels of different voices talking over each other, background noise versus speakers, etc. Equalizer presets simplify manipulation of specific parts of the audio, and they can be customized as needed, to help balance usability and control.
AI provides further forward-looking capabilities for voice analysis, including speech-to-text conversion using natural language processing. Automated transcription can be applied to all intercepted communications, making them easier to store, search, and analyze. Investigators can therefore identify relevant audio from large flows or repositories more quickly, without being overwhelmed by the need to manually listen to recordings.
In addition to manual queries, transcription also allows keywords, phrases, or names to be flagged to alert analysts when they occur in intercepted audio. This ability can efficiently and automatically draw attention to mentions of drugs, weapons, code words, or other content of interest. Automated translation helps overcome language barriers between subjects and investigators, including in cases where international investigations involve multiple languages.
Enhanced audio processing is seamlessly integrated with Intellego XT and Monitoring Center, making insights available from speech-to-text and other voice capabilities without additional effort. Emerging capabilities will extend analysis further, such as identifying individuals on calls and performing sentiment analysis. By adding dimensions of audio insight, SS8 is helping to once again elevate the status of voice in lawful intelligence.
About Rory Quann
Rory Quann is a Senior Solutions Engineer specializing in End-to-End Government Solutions at SS8 Networks and brings with him over 14 years of experience in the Lawful Interception and Data Analysis industry. Prior to joining SS8 in 2013, Rory worked for BAE System Applied Intelligence where he was focused on large scale Government deployments of Intelligence Solutions. Rory has held multiple positions in the Lawful Intelligence space ranging from Deployment Engineer, System Consultant, and Sales Engineer focusing on Country-wide Passive deployments. Rory is a Certified Microsoft MCSA Engineer and EMC Certified deployment Engineer. Learn more about Rory on his LinkedIn profile here.
About SS8 Networks
As a leader in Lawful and Location Intelligence, SS8 is committed to making societies safer. Our mission is to extract, analyze, and visualize critical intelligence, providing real-time insights that help save lives. With 25 years of expertise, SS8 is a trusted partner of the world’s largest government agencies and communication providers, consistently remaining at the forefront of innovation.
Intellego® XT monitoring and data analytics portfolio is optimized for Law Enforcement Agencies to capture, analyze, and visualize complex data sets for real-time investigative intelligence.
LocationWise delivers the highest audited network location accuracy worldwide, providing active and passive location intelligence for emergency services, law enforcement, and mobile network operators.
Xcipio® mediation platform meets the demands of lawful intercept in any network type and provides the ability to transcode (convert) between lawful intercept handover versions and standard families.
To learn more, contact us at info@SS8.com.