【Internet of Things Communication Technology】——Sigfox

Overview

In April 2022, French company Sigfox was acquired by Singapore-based IoT operator UnaBiz for 25 million euros. (UnaBiz is a Singapore-headquartered IoT service provider specializing in sensor product design, manufacturing, and data platform services. It leverages a hybrid of Low-Power Wide-Area (LPWA) technologies such as Sigfox, LTE-M, NB-IoT, and LoRa to drive business growth).

By the end of 2021, there were over 20 million IoT devices globally using Sigfox technology. However, the total number of global IoT connections had already reached 15 billion, with wide-area IoT device connections exceeding 2 billion. Therefore, Sigfox's 20 million share was minuscule. Poor management led Sigfox to file for bankruptcy protection with French judicial authorities in January of this year, culminating in its acquisition in April. The root cause of Sigfox's difficulties lay in its business model, particularly its insistence on handling all aspects of network construction and operation itself, which severely constrained its development. Sigfox acted as both the standard-setter and the network operator. It owned all core technologies related to network construction, deploying networks either in partnership with telecom operators or by building them independently, aiming to profit from controlling the network and cloud. This vertical integration—controlling everything from core technology and network deployment to operation—made it difficult to build synergistic partnerships to promote the technology widely.

History

Sigfox was founded in 2009 in the suburbs of Toulouse, southwestern France. From its inception to the present, the company completed 6 rounds of financing, raising a total of approximately 300 million euros. In addition to numerous overseas financial investors, many operators, chip manufacturers, utility companies, and hardware/software giants have invested in Sigfox, giving it a very strong shareholder lineup.

• 2011: Received a 2 million euro investment from Elaia Partner.
• September 2012: Raised 15 million euros from 5 institutions including Intel.
• March 2014: Raised 15 million euros from 7 companies including Telefónica and Intel.
• February 2015: Raised 100 million euros from 8 companies including SK Telecom, NTT Docomo, and Telefónica.
• November 2016: Raised 160 million euros from 7 companies including Salesforce, Intel, and IXO.
• May 2017: Secured funding from a Malaysian sovereign wealth fund, amount undisclosed.

Beyond its powerful investors, major chip companies were also eager to collaborate, with leading semiconductor firms being licensed to produce related chips.

1. 2014: Partnered with Silicon Labs.
2. 2014: Partnered with Atmel, resulting in the first SoC chip ATA8520.
3. 2015: Partnered with TI to develop low-cost chips.

However, the situation took a sharp downturn afterwards. According to reports, internal power struggles began within the management starting in 2017. Several executives chose to leave to avoid the conflict or were forced out after losing power struggles. Subsequently, IPO plans failed, financial targets could not be met, and the pandemic exacerbated the situation. During this period, its competitors—LoRa, NB-IoT, and LTE-M—developed and expanded rapidly without pause, further squeezing Sigfox's market share.

It is evident that even with good technology, survival is impossible without aligning with market rhythms, which is truly a pity.

Technical Principles

Sigfox operates in the 868MHz band in Europe, 915MHz in the USA, and within the 902-928MHz range in other countries/regions. Sigfox uses Ultra-Narrow Band (UNB) modulation technology to transmit signals within a 192kHz spectrum bandwidth in unlicensed bands. Each message transmission width is 100Hz, resulting in high power spectral density per unit bandwidth and strong anti-interference capability.

End devices send data packets formatted with the Sigfox protocol. Sigfox base stations receive this data and forward it to the Sigfox Cloud. The Sigfox Cloud then distributes the data to customer servers for parsing application information. Its product features include: Extremely low battery power consumption, enabling a lifespan of up to 10 years; Simple and easy to use, with very convenient and quick configuration between base stations and devices; Low cost, as Sigfox optimizes every环节 to reduce costs; Very small user data payload, maximum 12 bytes; and strong interoperability, making it easy for customers to use alongside other communication solutions.

• Ultra-Narrow Band (UNB) Technology: Uses a 192kHz spectrum bandwidth for data transmission, with each message transmission width of 100Hz, transmitting at data rates of 100 b/s or 600 b/s.
• Random Access: Data transmission between the network and devices is asynchronous. Sigfox's transmission rate is very low; a message with a 12-byte payload takes 2.08 seconds in the air, equivalent to a rate of 100 b/s.
• Collaborative Reception: Messages sent by a device can be received by any nearby base station and then forwarded to the Sigfox Cloud. This high-quality reception method ensures information reaches the cloud.
• Short Message Protocol: Sigfox can send short messages with a size of 0-12 bytes, e.g., GPS coordinates (6 bytes), temperature (2 bytes), speed (1 byte), status information (1 byte).
• Bidirectional Transmission: Downlink messages are triggered by the end device, and the cloud server assists the customer server in sending downlink messages.

Performance Comparison of Several Technologies

In comparison, Sigfox has clear advantages in transmission range and connection capacity.

Chip Suppliers

• NXP OL2385SFOOX
• Silicon Labs SI446x
• ON Semiconductor AX-SIP-SFEU
• Texas Instruments TI CC1120-CC1190
• Microchip ATA8520E

Module Suppliers

• Pycom SIPy 14dB
• Innocomm SN10-11
• Digital China
• Kaifa Technology

Related Resources

1. SigLinker: A Shanghai-based company relatively focused on Sigfox.
2. Huizhong Instrument: A listed company in Tangshan, Hebei, whose core technology is ultrasonic metering products.
3. Siterwell: Focused on overseas markets before 2016, then cultivated the Chinese market.
4. Ningbo Winenergy: Based on 2.4G Zigbee/LoRa/2G/4G/NB-IoT/SigFox wireless networks, it exchanges data with gateways using the IoT-based MQTT-SN data transmission protocol and provides diverse sensor interfaces.
5. Ding Heng Tai: Founded in Beijing in 2009, focusing on IoT. It has developed products based on Sigfox such as smart waste sorting bins, wireless gas cylinder monitoring, smart sanitation platforms, and parking space monitoring.
6. Official Resources - Related Transceivers
7. Official Resources - Related SoCs
8. Official Resources - Related Modules
9. Official Resources - Related Devices
10. Official Resources - Development Kits
11. Official Resources - Platforms
12. Official Resources - Application Solutions