> For the complete documentation index, see [llms.txt](https://docs.gxc.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.gxc.io/hw/5g/5g-fronthaul-multiplexer/fhm-specification-sheet.md).

# FHM Specification Sheet

Last Updated: 2026-02-23

<h4 align="center">Onyx Fronthaul Multiplexer</h4>

<figure><img src="https://4084968256-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FgSxa0NIdBp5aDw7Lf2N9%2Fuploads%2FgNCo7JBcWfd23lHXLOdN%2FFHM.png?alt=media&amp;token=5e1bcbc2-49c7-41a6-8b96-0a46f17b7e62" alt=""><figcaption></figcaption></figure>

The GXC Onyx Fronthaul Multiplexer (FHM) is a high-performance, versatile open networking device designed to expand coverage and maximize FU resources with flexibility as service providers improve their services by:

* Extending service coverage while minimizing DU resources needed by grouping RUs into virtual cells
* Cascading up to 8 FHMs (future)
* Compensating for various fiber length delays
* Supporting full SyncE and IEEE 1558 v2 (T-TC) &#x20;

### Hardware Specifications

<table><thead><tr><th width="250">Parameter</th><th>Specification</th></tr></thead><tbody><tr><td>Network Interfaces</td><td>8 x 10/25G SFP28 ports to O-RU<br>1 x 10/25G SFP28 ports to O-DU (4x future)<br>1 x 100/1000M RJ45 management port<br>1 x RJ45 serial console port (diagnostics only)<br>1 x USB 2.0 (type A) port (diagnostics only)</td></tr><tr><td>Timing Capabilities</td><td>ITU-T Synchronous Ethernet (SyncE)<br>IEEE 1588v2 T-TC</td></tr><tr><td>Weight</td><td>9.21 lb (4.18 kg)</td></tr><tr><td>Dimensions (H x W x D)</td><td>1 RU, 17.32 x 9.84 x 1.71 in (440 x 250 x 43.5 mm)</td></tr><tr><td>Redundancy</td><td>1+1 redundant PSUs (hot-swappable)</td></tr></tbody></table>

### Environmental Specifications

<table><thead><tr><th width="250">Parameter</th><th>Specification</th></tr></thead><tbody><tr><td>Power Supply</td><td>AC Input: (100~240) VAC, 3A<br>Max Power: 188 Watts</td></tr><tr><td>Operating Temperature/RH</td><td>-40°F to 158°F (-40°C to 70°C)<br>5% RH to 95% RH, noncondensing</td></tr><tr><td>Storage Temperature/RH</td><td>-40°F to 158°F (-40°C to 70°C)<br>5% RH to 93% RH, noncondensing</td></tr></tbody></table>

### Performance Specifications

<table><thead><tr><th width="250">Parameter</th><th>Specification</th></tr></thead><tbody><tr><td>Coverage</td><td>One FHM supports up to eight RUs<br>Cascading can be used to extend coverage (future)</td></tr></tbody></table>

### Regulatory Compliance

<table><thead><tr><th width="250"></th><th></th></tr></thead><tbody><tr><td>Safety</td><td>UL 62368-1<br>IEC 62368-1</td></tr><tr><td>Regulatory</td><td>FCC Part 15, Class A<br>CAN ICES-3 (A)/NMB-3(A)<br>Class A ITE</td></tr></tbody></table>

### Included Items

<table><thead><tr><th width="175">Item</th><th width="332">Description</th><th width="74">Qty</th><th>Notes</th></tr></thead><tbody><tr><td>Onyx FHM</td><td>Fronthaul Multiplexer</td><td>1</td><td>FHM Unit</td></tr><tr><td>Power Cords</td><td>NEMA 5-15P to C13 Wall Plug, 125 Volt, 15 AMP, 10 ft (3 m), Power Cord, North America</td><td>2</td><td>Included with FHM</td></tr><tr><td>SFP+ Transceivers</td><td>10G SFP+, 1310 nm, Single-Mode, Duplex LC, Long Range</td><td>2</td><td>Included with FHM</td></tr><tr><td>LC-to-LC Fiber Patch Cable</td><td>LC-to-LC Fiber Patch Cable Single Mode 10 ft (3 m)</td><td>1</td><td>Included with FHM</td></tr></tbody></table>

### Global Part Numbers

<table><thead><tr><th width="250">Parameter</th><th>Specification</th></tr></thead><tbody><tr><td>GXC-FHM-001</td><td>Onyx Fronthaul Multiplexer</td></tr></tbody></table>

\* Specifications and ID are subject to change without notice.


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