Multi-Protocol IoT Gateway Hub

I need a complete IoT gateway hub that brings LTE (4G), Wi-Fi, Bluetooth, Zigbee and sub-GHz RF into a single, reliable unit for remote monitoring and alerting of smart-home devices. The goal is straightforward: gather data from a variety of in-home sensors and actuators, push it to the cloud over cellular when Wi-Fi is unavailable, and relay actionable alerts back to the user in real time. Here is what I expect: • Hardware design that accommodates the five radios with proper coexistence planning, power management and antenna layout. • Embedded firmware that can automatically select the best back-haul (LTE or Wi-Fi), maintain secure connections and expose a clean API or MQTT/HTTP interface for the smart-home layer. Also with bluetooth, zigbee and rf. • Deliverables including schematics, PCB files, firmware source, build instructions and a short test report confirming radio performance and end-to-end alert latency. If you have previous experience blending multiple wireless stacks on resource-constrained hardware and can move from design to working prototype, I would love to review your proposal and timeline.