Senior Modem Firmware Engineer - OpenWrt + 5G

Ericsson; Santa Clara (CA); On-site; USD 120,000 - 150,000; Full time

Benefits offered by this job

Health insurance

401(k) plan with match

Paid time off

Parental leave

Life and AD&D insurance

Dental and vision coverage

Job summary

Ericsson Inc. is seeking a Senior Modem Firmware Engineer in the United States to design, develop, and integrate cellular modem modules into OpenWrt-based platforms.

You will own the end-to-end modem stack—from kernel drivers to user-space daemons and network configuration—to deliver reliable connectivity and high throughput across 5G networks. You will collaborate with hardware teams, optimize performance, and implement robust failover and provisioning features, while mentoring junior engineers

Qualifications

• 4+ years in embedded Linux development; 2+ years with OpenWrt or similar distributions.
• 2+ years integrating cellular modems (prefer: 5+ years across multiple vendors).
• Linux kernel development: driver development, device tree, kernel modules.
• OpenWrt/LEDE build system and package development.
• Cellular modem integration: QMI, RMNET, AT commands.
• USB/PCIe modem interface drivers.
• C/C++ programming for embedded Linux systems.
• Cross-compilation toolchains and embedded build systems.
• Bachelor’s degree in Electrical Engineering, Computer Engineering, Computer Science, or related field (Master’s preferred).

Responsibilities

• Integrate 5G modem modules into OpenWrt-based router and gateway platforms.
• Develop and maintain kernel drivers for modem interfaces (USB, PCIe).
• Implement and optimize QMI/RMNET/AT command interfaces for modem control.
• Configure network interfaces, routing policies, and failover mechanisms.
• Implement connection management daemons for automatic reconnection and band selection.
• Integrate SMS, GPS/GNSS, and voice functionality where applicable.
• Optimize data throughput and reduce latency across modem interfaces.
• Perform modem firmware updates (FOTA) and version management.
• Debug connectivity issues across full stack (RF, baseband, driver, user-space).
• Collaborate with hardware teams on antenna design validation and RF performance.
• Create integration documentation and developer guides.

Skills

Embedded Linux

OpenWrt

Cellular modems

Linux kernel development

OpenWrt LEDE build

QMI RMNET AT commands

USB PCIe drivers

C/C++

Cross-compilation

Bachelor’s degree (EE/CS)

Education

Bachelor’s degree in Electrical Engineering, Computer Engineering, Computer Science, or related field

Master’s degree preferred

Tools

Qualcomm SDX-series modules

Quectel/Telit modules

ModemManager

VPN: WireGuard/OpenVPN/IPsec

eSIM/eUICC provisioning

Multi-WAN failover (mwan3)

Job description

Ericsson Inc. is seeking a Senior Modem Firmware Engineer in the United States to design, develop, and integrate cellular modem modules into OpenWrt-based platforms.

You will own the end-to-end modem stack—from kernel drivers to user-space daemons and network configuration—to deliver reliable connectivity and high throughput across 5G networks. You will collaborate with hardware teams, optimize performance, and implement robust failover and provisioning features, while mentoring junior engineers