Harmonic achieved a new DOCSIS 4.0 performance milestone by demonstrating 14 Gbps downstream throughput at a recent CableLabs interoperability event. The record-breaking test, performed across a multi-vendor network, leveraged Harmonic’s cOS™ virtualized broadband platform and Pebble-2 Remote PHY Device (RPD). This result exceeds the DOCSIS 4.0 benchmark target of 10 Gbps, reinforcing the platform’s readiness for real-world deployments.
The CableLabs event serves as a proving ground for vendor interoperability of DOCSIS 4.0 technology, including Full Duplex (FDX) and Frequency Division Duplex (FDD) modes. Harmonic’s cOS platform is the first in the industry to support both DOCSIS 4.0 variants, giving operators greater flexibility in network design and upgrade paths. The interoperability tests, which included modem, RPD, and core system integration, are crucial to advancing certification and accelerating broadband rollouts.
Harmonic’s platform currently supports over 33 million broadband devices globally and leads the market in virtual CMTS and distributed access architectures (DAA), according to Dell’Oro Group. “This major milestone demonstrates that our cOS platform is primed to support DOCSIS 4.0 rollouts, enabling the standard’s full set of downstream and upstream speed options with fiber-like symmetric multigigabit speeds,” said Asaf Matatyaou, SVP of Product at Harmonic.
- Harmonic demonstrated 14 Gbps downstream throughput at CableLabs DOCSIS 4.0 interop
- Utilized Harmonic’s cOS virtualized broadband platform and Pebble-2 DOCSIS 4.0 RPD
- Surpasses 10 Gbps DOCSIS 4.0 benchmark target
- cOS supports both FDX and FDD deployment modes
- Platform currently powers over 33 million broadband CPE devices globally
- DOCSIS 4.0 leverages Orthogonal Frequency Division Multiplexing (OFDM) with higher modulation orders (up to 4096-QAM) for better spectral efficiency. It introduces advanced error correction (LDPC) and dynamic spectrum sharing to optimize performance. FDX requires new amplifiers and nodes, while ESD extends spectrum usage, both demanding significant network upgrades.
- Extended Spectrum: Utilizes up to 1.8 GHz of spectrum (compared to 1.2 GHz in DOCSIS 3.1), increasing capacity through Full Duplex (FDX) and Extended Spectrum DOCSIS (ESD).
- Full Duplex Capability: FDX allows simultaneous upstream and downstream traffic in the same spectrum, doubling efficiency.
- Low Latency: Enhanced queue management and proactive network maintenance reduce latency, critical for real-time applications.
- Backward Compatibility: Supports existing DOCSIS 3.1 and 3.0 infrastructure, easing operator upgrades.







