Wireless Systems Engineer

Randall
Fassbinder

15 years in the guts of cellular networks — 5G, LTE, and IoT — now building on the device side.

Chicago, IL · open to remote
U.S. Patent
Wireless device-state monitoring
US 2024/0397298 A1
IEEE Published
Extended-Range mmWave
97th ARFTG Measurement Conf.
World Record
mmWave Fixed Wireless
Furthest & fastest FWA, 2020
Experience
15+ Years
5G NR · LTE · NB-IoT · mmWave

About

I've spent 15 years in the guts of cellular networks — designing test plans, validating live 5G and LTE deployments, and driving root-cause analysis across the full protocol stack, from the modem and radio layer through the carrier core to the application server.

Along the way I've been the technical bridge between carriers, equipment vendors, and 3GPP standards, led an NB-IoT deployment end to end, and set a world record for mmWave fixed-wireless range — work that also earned a U.S. patent and an IEEE publication.

Now I'm bringing that depth to the device side. The cellular systems I tested from the network are built on modules and silicon that need people who understand both the radio and the integration. That's the work I'm building toward — hands-on, one project at a time.

Featured Project

Cellular GPS Tracker

● Build in progress

A Linux + cellular + GNSS tracker for my motorcycle — it reports live location over LTE to a self-hosted map and pings me if the bike moves when it shouldn't. Built on a Qualcomm-based SIM7600 module: the same class of hardware the cellular-IoT industry ships at scale.

Raspberry Pi · Linux SIM7600 · LTE Cat 4 + GNSS AT commands / UART Traccar MQTT
What it demonstrates

Embedded Linux, cellular module bring-up over AT, a live LTE data session, GNSS integration, and cloud reporting — the full device-side stack, end to end.

Build log ↗

Experience

T-Mobile
2025 – 2026
Lead RAN Engineer — Strategy & Architecture
Cross-domain integration across RAN, Core, and Transport during large-scale MOCN rollout; deep log analysis and Python diagnostics frameworks across LTE and 5G NR.
UScellular
2014 – 2025
Lead RAN Engineer — Strategy & Architecture
Owned NB-IoT deployment end to end; led multivendor mmWave interoperability trials; primary technical interface to Ericsson and Nokia; world-record mmWave FWA and IEEE publication.
AT&T Mobility
2010 – 2014
Specialist RAN Engineer
Led RAN optimization and drive-test across the Chicago market; on-air verification for new LTE and WCDMA builds, DAS, and in-building systems.

Skills

Cellular
5G NR, LTE / LTE-Advanced, NB-IoT, LTE-M, mmWave, EN-DC, 3GPP (PHY→app)
Diagnostics
QXDM, QCAT, Wireshark, TEMS, Accuver
Software
Python, R, Bash, C / C++, Linux, SQL
Embedded & IoT
u-blox / SIM7600 modules, AT commands, UART, GNSS, MQTT

B.S. Electrical Engineering, University of Illinois Urbana-Champaign · MBA, Saint Xavier University