LoRaWAN has become a go-to choice for IoT deployments thanks to its long range, low power, and massive coverage capabilities. Interestingly, while the LoRa physical layer theoretically supports spreading factors (SF) from SF5 to SF12, the official LoRaWAN standard only uses SF7 to SF12. So, what happened to SF5 and SF6?
What is Spreading Factor (SF)?
In LoRa modulation, the SF defines the balance between range and data rate. A higher SF results in longer range but lower data rate; a lower SF provides higher data rate but shorter range.
Although SF5 and SF6 exist technically, they were deliberately left out of the LoRaWAN standard for several reasons.
Why are SF5 and SF6 excluded?
1️⃣ Hardware limitations
When LoRaWAN v1.0.x was developed, chipsets like Semtech’s SX127x didn’t fully support SF5 and SF6, especially for low-power operations and consistent sensitivity.
2️⃣ Focus on wide-area networks
LoRaWAN was designed primarily for long-range, low-data-rate communication to cover large areas. SF5 and SF6 are better for short-range, high-speed transmissions, which contradicts this design philosophy.
3️⃣ Network stability and interference
While lower SFs reduce time on air, they can introduce more interference in dense deployments, affecting overall network reliability.
Are SF5 and SF6 useful?
Definitely! They offer:
- Higher data rates, perfect for fast data bursts in close-range scenarios.
- Lower power consumption, allowing quicker wake-up and transmission cycles.
- Reduced air-time, improving network capacity.
Thus, SF5 and SF6 are widely used in private LoRa networks, point-to-point communications, and customized industrial setups.
How does Manthink address this?
Manthink recognizes the value of all possible SFs for different use cases. Besides strictly following LoRaWAN, our solutions support SF5 and SF6 in private or hybrid deployments:
- OMx22S LoRaWAN module: supports various industrial protocols and can be adapted to faster SFs when needed.
- SE72 temperature & humidity sensor: 8-year battery life, ideal for dense indoor or campus settings.
- GDO51x outdoor and GDI51x indoor gateways: robust and multi-band for versatile network setups.
- ThinkLink LoRaWAN NS: supports up to 1,000 free device connections, with flexible SF configurations to match application needs.
Will SF5/SF6 be added in the future?
With chip advancements (e.g., Semtech SX126x series), supporting SF5 and SF6 may become easier. While not officially included in the standard yet, discussions and pilots are already happening. Future updates might embrace these lower SFs under certain conditions.
Final words
SF5 and SF6 were excluded from LoRaWAN to prioritize long-range, robust network performance. However, as IoT requirements diversify, these “forgotten” SFs might gain more attention.
Manthink will continue to push LoRaWAN innovations forward. If you’re interested in higher-speed, short-range, low-power applications, get in touch — let’s unlock new possibilities together!