Near real-time, low power, wireless connectivity
Several connected, battery operated, sensors/actuators in dynamic environments
RIIoT is an RF system designed to meet the sensor and actuator connectivity requirements for the Industrial IoT. The RF protocol is the IEEE802.15.4 g/e standard with RIIoT additions. RIIoT includes an Intelligent C-programmable I/O (i:zi), which makes it possible to directly interface to any sensor or actuator.
Radiocrafts’ commitment to making connectivity easy for network designers working across a variety of radio frequency networks was the driving motivation for developing the RIIoT additions to IEE802.15.4 g/e standard.
The RIIoT system consists of the following parts:
- The RIIoT Network Controller
- The RC188x-SPR, the RIIoT leaf node module
- The RC188x-GPR-GW, a stand-alone gateway dongle
- The RIIoT development tools
RIIoT secures data in-flight using AES128-CCM, an encryption scheme that offers confidentiality, integrity, and authenticity assurances. AES128-CCM offers protection against eavesdropping, modification, replay, and impersonations.
Unique Key per Link
A unique AES key is established between each node and the coordinator using Elliptic Curve Diffie-Helman (ECDH). So even if one node is compromised, data from the rest of the network is still secured.
RIIoT users can also opt-in for end-to-end security to encrypt data all the way from the end node to the user cloud application. With end-to-end security, data is protected from eavesdropping or modification even in the gateway that is responsible for routing.
RIIoT users can also use a “whitelist” so only approved nodes are accepted into the network. A whitelist requires a verification of the node’s security credentials prior to it joining the RIIoT network.
Future-proof with Over-the-Air updates
Your product will be future-proofed by RIIoT’s over-the-air updates. OTA updates are possible because of RIIoT’s two-way communication channel and the module’s internal flash memory.
You can upgrade your RIIoT nodes in the field with new sensor/actuator interfaces, new signal processing algorithms, and updated security patches. You can also keep the underlying RF system firmware current using RIIoT Over-the-Air updates.
Frequent Readings/Updates are possible due to the short pulse length in IEEE802.15.4 e/g and the low overheads in the CBOR protocol. This ensures that many messages can be sent during the space of an hour, without violating the 1% duty cycle that is imposed by radio regulations. The RIIoT message length (45ms) is less than 3% of a LoRaWAN long range message or a Sigfox message.
High node count
RIIoT networks support a high node count per gateway driven by the short transit pulse time. This is important for two reasons:
- The risk of interference between simultaneously sending nodes is reduced
- It makes the 1% duty cycle regulatory requirement achievable with many nodes in the same network.
Radiocrafts has done tests with RIIoT using 28 nodes sending data randomly every 10 seconds to one gateway. We achieved amazing results having 99.8% good packets received.
Interface to any sensor or actuator
The Intelligent C-programmable I/O (i:zi) for the programmable node, the Radiocrafts RC188x-SPR, comes with APIs to read and write to the local interfaces, including UART, I2C, SPI, GPIO and ADC. This flexibility allows the user to integrate to any sensor or actuator or any combination of sensors and actuators.
Low current TX/Rx/Sleep
- TX 8.5 mA @ 0 dBm
- TX 19 mA@ 12 dBm
- TX 26 mA@ 14 dBm
- RX 6.2 mA
- Sleep 0.7 mA (RTC based on crystal 0.7 mA)
Short Tx/Rx times
The TX signal length for 12 bytes application data is 4.5 ms, which is very short in sub-gig LPWAN transmission technologies. See the technology comparison below. The total energy transmitted per packet is calculated and the minimum average time between transmissions calculated. This is a measure on how often a sensor can be read on a 500mAh battery if the battery should last years. For a battery-operated system with many sensor readings, this a critical parameter.
Long sleep time
RIIoT has no mandatory background communications that would require frequency wake-up. This means that in a smart end node application — where data processing is done in sensor node and RF packets are only sent during alarms — a radio in the sensor node can be sleeping for hours, or even days. Smart end-node applications are supported in RIIoT using the Intelligent C-programmable I/O (i:zi) supported by the RC188x-SPR leaf node module.
In addition, RIIoT uses smaller energy pulses, further extending battery life. This is an important network design/cost consideration, since coin cell lithium batteries do not like large pulses of current — making them unsuitable for LPWAN technologies. Bigger (e.g., AA cell) lithium batteries need supercapacitors for handling the Tx current bursts, but that dramatically increases network costs.
RIIoT, therefore, is well suited for applications wanting to use low cost coil cell batteries and no costly supercapacitors.
Long RF range
RIIoT RF is based on the IEEE802.15.4g/e standard with RIIoT additions in the application layer. RIIoT RF creates a robust long-range network, with a range sufficient for most industrial applications.
The following table shows calculations of RF ranges for various networks. The RF ranges were calculated using an empirically derived formula that is an industry standard; namely, “the Free Indoor Model,” which is also applicable for the outdoor urban environment:
LP = Path loss
R = Range
Path loss is given by LP = P0 – n*10*log10 R
PO (Path loss at 1m ) = 20 * log(300/4*PI*frequency)
We use n=3.6 as typically used for factories with an obstructed line of sight. See our application note AN021 for further details on the model.
Tx power is limited to 14 dBm for 868, 27 dBm for 169, and 7dBm for 2.4Ghz in these calculations.
RIIoT RF has a practical range of over a kilometer.
Optimized for Gateway and Cloud Integration
The RIIoT Network Controller, “RIIoT Net”, is a provided Linux middleware that makes it easy to both manage the RF network and route data to user gateway applications or the Cloud.
The controller provides a socket interface for user applications, making RIIoT compatible with any platform and user application written in any language. Data from RIIoT networks are forwarded to user applications as JSON objects that are easily parsed and forwarded to the Cloud.
RIIoT offers an optional application layer that models a node with attributes, actions, and event notifications — representations that are easily mapped to data models in cloud services.
Data on the network are encoded in CBOR (Concise Binary Object Representation), a binary encoding that models after JSON. CBOR has the advantages of being fast and power-efficient while allowing the RIIoT net controller to translate it to JSON — which can be easily parsed by gateway and cloud developers.
For RF network reliability, RIIoT RF leverages various established techniques that reduce vulnerability to interference, avoid noisy environments, and recover poorly received packets. RIIoT RF also has a built-in network monitor that can send alarms when links are malfunctioning.
To avoid noise interference when info is received, the signal length should be as short as possible; RIIoT RF achieves this by using 50/5kbs data rates and very low overheads.
To avoid interference so as to hit the open window in the frequency plane, RIIOT uses low bandwidth, and good Rx filtering.
Frequency hopping helps to avoid interferences as noisy channels are automatically avoided.
“Interference tolerance” is the signal level required to possibly distort a data packet that otherwise would be received OK. A higher interference tolerance number is better than a lower number, allowing a transmitter that causes the interference to be located closer to the RIIoT device without interference.
Ack/retry ensures that good data is received but is only possible if the signal length is relatively short, as supported by RIIoT RF. It provides a very robust reliable transmission process. If the data is not received, the module will repeat the data until it is received properly. The alternative (less desirable) approach is to initially send more data than may be needed, e.g. send the same data more than once (Sigfox) or add forward correction bits (LoRa). Ack/retry is only possible if the signal length is relatively short, as supported by RIIoT RF.
Network monitoring adds reliability as it continuously checks the quality of the network and sends alarms if performance goes down.
The takeaway for industrial RF network designers is that RIIoT is well suited for high reliability/QoS types of applications: The probability of interference (in time, frequency, and signal space) is low; RIIoT supports frequency hopping; and there are good mechanisms to recover information from a packet loss (Acknowledge and retransmission).
Symmetrical down and uplink communication
The IEEE802.15.4.e/g supports symmetrical communication which means that messages can be sent at full speed both uplink and downlink. Good bi-directional communication is critical for any control application and also for making firmware Over the Air updates (OTA).
Short time to market
Designed to be very easy to implement, the RIIoT system features:
- High quality RF modules that remove most of the RF hardware design issues
- Intelligent C-programmable I/O (i:zi) on leaf-node modules allows the designer to implement a custom application in less than 100 lines of high-level C code
- The RIIoT RF protocol, RIIoT RF, with built-in features for low power consumption, long range, high reliability, and advanced security
- The RIIoT Network Controller (“RIIoT Net”), which eases gateway integration and cloud connectivity, monitors the network functionality, and provides for an easy network set-up
- A separate gateway dongle, RC188x-GPR-GW, interfaces to a Commercial off the shelf (COTS) gateway via USB, making the gateway solution simple to implement, the RC188x-GPR can be integrated in the gateway as an alternative solution.
RIIoT provides a complete RF subsystem that can interface to any sensor or actuator, while taking data to and from the Cloud, via a gateway/concentrator, with industrial grade performance. The complete network can be designed and set-up in a matter of days. Cloud connectivity is easily implemented with RIIoT Net using a standard Linux-based gateway with internet access.
The RIIoT products
RIIoT network controller, RIIoT Net
The RIIoT network controller (RIIoT Net) resides on the network’s gateway. RIIoT Net is part of a Radiocrafts Linux software package, and it’s designed for easy installation on a Linux-based gateway.
RIIoT Net can be easily integrated into a user application through a socket. Data and commands are communicated as JSON objects. The main functions of the network controller are:
- Supporting the set-up of the RF network
- Monitoring the network for broken links, etc
- Managing low-level networking through the RC188x-GPR module
- Conversion between RIIoT RF CBOR encoding to JSON data
- Managing over-the-air firmware update of leaf nodes
Go to the RIIoT Net product page.
RC188x-SPR leaf node module
The Radiocrafts RC188x-SPR is a programmable RF module that is compatible with IEEE802.15.4 g/e and RIIoT RF. In addition to being used as part of Radiocrafts Industrial Internet of Things (RIIoT), the RC188x-SPR module can also be used as a leaf node in other IEEE802.15.4 g/e RF networks.
The RC188x-SPR is programmed through an Intelligent C-programmable I/O (i:zi), so users can write their own application code in high-level C language. This programming efficiency is useful for managing sensor and actuators, creating local alarms, doing signal processing, etc.
RC188x-GPR gateway processor module
Radiocrafts RC188x-GPR is an IEEE802.15.4 g/e compatible modem module for the gateway/concentrator. The modem module supports RIIoT RF and can interface to several hundred RC188x-SPR nodes.
The RC188x-GPR module can be used together with the RIIoT network controller – RIIoT Net— the Radiocrafts provided Linux middleware that makes it easy to communicate on the RF network. Alternatively, user applications can directly interface with the RC188x-GPR using the UART.
RC188x-GPR-GW (Gateway Dongle)
The RC188x-GPR-GW is a stand-alone gateway dongle that includes the RC188x-GPR module and a USB transceiver. This dongle can be added to a Commercial Off the Shelf (COTS) Linux gateway with a USB interface, to create a complete RIIoT Gateway. The dongle comes with an antenna, a USB cable and a power adaptor. The dongle is certified and ready to be operational.
Go to the RC188x-GPR-GW product page (to be released).
RIIoT tools to accelerate your development
RC1880-SPR SDK – A software development kit for programming the RC188x-SPR leaf nodes. The kit comes with an Intelligent C-programmable I/O (i:zi) with high-level C APIs that allow you to interface to any sensor or actuator, and to implement any data processing and edge intelligence function.
Using less than 100 lines of code, you can write a full application for sensor interfacing and networking. For more complex applications, up to 10K of space is available. The SDK kit comes with a free development environment, a compiler, and flashing tools.
RIIoT Network Dashboard – A browser-based GUI that connects to the RIIoT network controller to manage your network and visualize its data.
RIIoT RF Link Test – A tool to test the RF range and signal in your environment.
Please go to the RIIoT development tool documentation and RIIoT product pages if you want to learn more about RIIoT.
Go to the RIIoT Tools product page.