How do you select a wireless technology for a new embedded product?

Wireless technology selection is a system-level decision that must be made early in the product definition phase, as it impacts PCB layout, antenna design, power architecture, regulatory certification, and software stack. The decision framework starts with four primary criteria: data rate requirements (bytes per second of application data), range (indoor, outdoor, urban, rural), power budget (line-powered, rechargeable battery with size constraints, coin cell for years), and network topology (point-to-point, star, mesh, internet connectivity needed).

Map your requirements to the technology landscape: if you need internet connectivity and are line-powered, WiFi is the default choice — it leverages existing infrastructure, has mature software stacks (TCP/IP, TLS, HTTP/MQTT), and users already have routers. If you need short-range communication with a smartphone and low power, BLE is the standard — every phone supports it, the ecosystem is mature, and power consumption in the tens-of-microamps range enables coin-cell operation. If you need long range (kilometers) with small payloads and extreme battery life, evaluate LoRa (ISM band, no subscription) versus NB-IoT/LTE-M (licensed spectrum, carrier subscription, better reliability and coverage). If you need mesh networking for home or building automation, Thread/Matter or Zigbee are purpose-built. If you need high-precision ranging, UWB provides centimeter-level accuracy.

Beyond the primary criteria, evaluate secondary factors: regulatory requirements by target market (FCC, CE, TELEC — each has different rules for ISM bands, duty cycle, and TX power), module availability and cost (a certified WiFi/BLE combo module like ESP32 costs under $2, while a cellular module costs $10-30 plus subscription fees), ecosystem maturity (BLE has excellent smartphone SDKs; LoRaWAN has standardized network servers; Thread/Matter has growing but still maturing tooling), antenna size constraints (sub-GHz antennas are physically larger than 2.4 GHz), coexistence with other radios on the same board, and the engineering team's experience. In an interview, demonstrate that you think about the full product lifecycle — not just the radio specification sheet, but the certification cost, manufacturing test strategy, field update mechanism, and end-user provisioning experience.