NB-Fi is an LPWAN protocol that supports secure bidirectional communication for Internet of Things (IoT), machine-to-machine (M2M) and Industrial Internet of Things (IIoT) applications. NB-Fi makes it possible to realize the enormous potential of the Internet of Things by collecting and analyzing data from end devices for analytical, accounting, billing and ERP systems.

NB-Fi technology ensures wireless communication between devices in hard-to-reach places over long distances in dense urban areas, being perfectly fit for the building of IoT networks, deployment of automated metering systems for utilities, Smart Grid and Smart City projects, wireless solutions for industrial, agriculture, monitoring and alarm systems. NB-Fi is an open standard with disclosed format of NB-Fi messages and relevant technical data required for manufacturers to produce compatible IoT end devices.

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NB-Fi technology overview

LPWAN technologies may be divided into two groups: Wideband and Narrowband systems. In Wideband systems, one channel typically occupies a frequency band with a width from 100 kHz to several MHz, while in Narrowband systems one channel has a bandwidth from 50-100 Hz.

Technologies of low-power narrowband radio communication began rapidly developing in the world on the back of the improvement of oscillators' accuracy, which allowed increasing the duration of signal stability: it became possible to narrow the transmission band preserving the signal power limits. Long duration of signal stability in Narrowband systems allows transmitting data at a low data rate at distances of 10 kilometers and more without exceeding the power limits in unlicensed bands (typically, from 25 to 100 mW). One of the advantages of Narrowband systems, such as NB-Fi (“Narrow Band Fidelity”), is the effective use of radio frequency spectrum. The width of one NB-Fi frequency channel starts from 50 Hz. NB-Fi devices use the 50 kHz bandwidth for Uplink messages and the 100 kHz bandwidth for Downlink messages, which are only small channels inside the allowed license-free ISM bandwidth. Thousands of NB-Fi channels can be accommodated simultaneously within these bandwidths. The narrowband signal and high energy per bit of transmitted information provide for an excellent energy potential for the link budget and a high noise immunity.

Key advantage of the highly sensitive NB-Fi base station is its ability to receive a signal with a low SNR – down to zero, i.e. when the signal level does not exceed the noise level. Base stations use advanced filters to provide an unrivaled level of dynamic range of a signal. NB-Fi base stations can process thousands of channels simultaneously, digitizing the entire bandwidth in real time and receiving the messages which were sent at different data rates.

Spectrum of the NB-Fi base station: receiving signals with different data rates (narrow bands – low data rates, wide bands – high data rates)

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Specification of the NB-Fi protocol

NB-Fi standard supports bidirectional (Uplink and Downlink) communication. This is primarily required for end devices like electricity meters, where a Downlink channel allows controlling the meter: time synchronization, tariff schedule update, load relay switch off etc. NB-Fi transceivers built into end devices, together with sophisticated signal reception algorithms, ensure almost symmetrical communication channel in both directions.

NB-Fi standard for bidirectional communication supports the adaptive data rate. If the signal strength is good, devices will automatically switch to a higher data rate. This allows using the spectrum efficiently and reduces the consumption of power necessary for transmitting data. NB-Fi standard supports up to 4.3 billion devices in a single network with a 32-bit ID for each device. NB-Fi does not use IP addressing (IPv4, IPv6) in order to optimize the payload. IoT devices (such as sensors and gauges) can transmit tiny few-bytes data packages. The minimum size of an IP header is 20 bytes, thus the Non-IP Data Delivery (NIDD) approach allows developing simpler and cheaper devices. Data exchange between devices and third-party applications is possible via the NB-Fi server's API.

NB-Fi UPLINK overview

XX ---- XXXX ---- XX
Minimum reception bandwidth of the NB-Fi base station 51.2 KHz
Data rate 50, 400, 3200, 25600 bps
Packet length 288 bits
Modulation DBPSK
Multiple access method Time & Frequency
Number of simultaneously received channels in 51.2 kHz bandwidth 1024 (at the data rate of 50 bps)
128 (at the data rate of 400 bps)
16 (at the data rate of 3200 bps)
1 (at the data rate of 25600 bps)
Ultimate reception sensitivity -150 dBm (for the data rate of 50 bps)
-141 dBm (for the data rate of 400 bps)
-132 dBm (for the data rate of 3200 bps)
-123 dBm (for the data rate of 25600 bps)
UPLINK packet reception throughput of one NB-Fi base station 20 Mbit/day

NB-Fi MAC and Transport Layers overview

XX ---- XXXX ---- XX
Network numbering capacity 4.3 billion devices (232)
Effective data rates
12.5, 100, 800, 6400 bps
Encryption algorithm AES-256 or other symmetric block cipher algorithm with 256-bit encryption key
Payload for one NB-Fi packet 8 bytes
Maximum payload length for a group packet at Transport layer 240 bytes
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NB-Fi vs. other LPWAN technologies

LPWAN systems are used to transmit data over long distances successfully, using both narrowband and broadband signals. Each of these systems has its pros and cons –the right technology should be chosen depending on technical requirements and other considerations.

NB-Fi technology is focused on energy efficiency and extra long battery life of devices, and is designed for solutions that require fast and inexpensive rollout of IoT networks with a 100% data collection rate from the devices. The comparison among NB-Fi and other LPWAN technologies is below.

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Key advantages of NB-Fi

Exceptional receiver sensitivity WAVIoT base stations have the highest possible receiver sensitivity down to -148 dBm (at a data rate of 50 bps), which allows achieving the maximum possible line budget in the NB-Fi network and a long range of data transmission. NB-Fi transceiver also has a high receiver sensitivity down to -148 dBm (at 50 bps data rate @869 MHz).
Sophisticated cryptographic algorithms The implementation of secure data exchange between NB-Fi devices and a cloud server ensures the confidentiality and integrity of the information between the devices and the base station, as well as between the base station and the NB-Fi server. NB-Fi uses the AES-256 encryption. Other symmetric block cipher algorithms with a 256-bit encryption key may be used.
Full technology stack and complete NB-Fi products portfolio WAVIoT develops the full range of products for IoT networks, from the NB-Fi transceiver to various types of IoT devices and the IoT Platform. This allows building corporate or global IoT networks that will use just one NB-Fi technology in multiple applications.
Working in the license-free ISM band NB-Fi protocol requires only 200 kHz of spectrum and can operates in license-free ISM radio band.
Scalability and reliability of NB-Fi networks NB-Fi allows building global, stable and scalable IoT networks with millions of NB-Fi devices connected to a single IoT platform. Noise stable NB-Fi networks ensure 100% of uptime – NB-Fi networks cannot be legally suppressed without specialized equipment.
An open NB-Fi protocol WAVIoT provides developers with NB-Fi libraries and relevant technical data that allows developing your own IoT devices. Customers can rollout on-premises IoT networks or use the global IoT platform. WAVIoT also provides NB-Fi Development Kits and NB-Fi transceivers that support the NB-Fi standard at the physical level.