How sound can bridge the gaps in the Industrial IoT ecosystem
In recent years, the growth of the Industrial Internet of Things (IIoT) has started to provide unprecedented levels of visibility and control in industrial environments, thanks to the proliferation of smart devices and networked sensors.
However, not all industrial environments are able to reap the full rewards of the IoT revolution.
Many suffer a range of unique communication and networking challenges, such as regulatory restrictions on the use of radio frequency (RF) networking technologies and restrictions on the installation of cabling. This is typically due to electromagnetic waves produced during manufacturing processes which could disrupt the RF-based communications, or conversely possible disruption to the plant equipment caused by RF networking gear.
In fact, RF wireless communications do not meet regulatory standards in many major industrial environments. Current best practices recommend prohibiting RF communications in safety-critical systems such as nuclear facilities, and the same applies to many parts of the electromagnetic spectrum in medical scenarios. This impacts the majority of popular communications technologies, including Wi-Fi, Bluetooth, cellular, ZigBee and DECT.
A solution to these challenges is the emerging field of data-over-sound. Using streams of audio tones, devices can exchange information using nothing but a speaker and microphone. First popularised in the consumer realm by the Chirp app and ecosystem, this technology is now mature and battle-tested, and available to developers in a range of cross-platform SDKs.
In an industrial setting, equipment that was previously isolated can communicate with the plant’s network, technicians’ hand-held devices, or even other autonomous equipment in a machine-to-machine configuration, delivering the operational and productivity benefits of IoT where they weren’t previously available.
Requiring low setup costs and minimal hardware infrastructure, sound-based networking provides a bridge that can interconnect vastly different generations of technology.
Sound as a networking tool
Sound has long been used as a means of sending data. Every day, we use sound to convey information using speech. In radiotelephony, techniques such as Morse code could be used to transmit text over lossy links. More recently, dial-up modems used audio-based modulation to exchange data over the phone line.
This technology has recently been re-invented for the age of IoT. Breakthroughs in encoding and decoding technology meaning that it’s now possible to transmit data over sound between devices that are spaced metres apart: any device with a speaker can encode and play information in the environment. Any nearby device with a microphone can then decode the data – as long as it is within hearing range.
Just like with RF technologies, there are various different schemes and standards for transmitting data using sound, and some use different frequency bands. Most popular data-over-sound technologies use some variant of frequency-shift keying, which gives relatively high throughput and reliability in over-the-air environments. Implementations vary between their use of the audible and ultrasonic (inaudible) portions of the acoustic frequency spectrum.
Whilst sound can be used to facilitate communication between offline devices and equipment, it also complements existing network infrastructures by creating a wireless, data-over-sound link between previously-offline devices and the wider area network.
As a complementary technology, data-over-sound also represents a compelling addition alongside RF networking standards because of several key characteristics: It is simple, ubiquitous and extremely portable.
Chirp is the most mature and trusted player in the field of data-over-sound, with adoption in over 90 countries. In this post, we’ll refer to a couple of of the specific affordances that we think sets Chirp’s technology apart.
Data-over-sound technology has several powerful affordances in industrial environments:
- Does not need a network: Data can be encoded and transmitted using streams of sound. No network connection is required to send or receive data.
- No device pairing: Unlike many networking solutions like Bluetooth, devices are not required to go through any prior handshake process before they can exchange data. This reduces operator time and eliminates error-prone and unreliable communications methods.
- Robust to noise: Although many industrial environments have high levels of background noise, Chirp‘s decoding algorithms are specifically designed for environments that are noisy and acoustically challenging. The decoding process can additionally be tailored to specific acoustic environments, optimising reliability to your specific working environment.
- Leverages existing audio infrastructure: Sound can utilise existing audio infrastructure such as PA systems to transmit data. This means even devices and equipment widely dispersed around a factory or station can be communicated with as long as they are within earshot of a speaker. Note that typical PA systems cannot broadcast the ultrasonic band effectively – an audible encoding such as Chirp’s standard audio protocol should instead be used.
- 2-way communications: Because any device with a speaker and microphone can act as a sender and receiver of data, sound can facilitate frictionless two-way M2M communications without requiring a network. Call-and-response exchanges allow you to ensure that data has been transmitted successfully end-to-end, with the option of responding with an updated status at the receiving end.
- Enables air-gapped security: Because devices are not ‘connected’ by wires or Wi-Fi, equipment can report back but still maintain a secure air gap with the network. Chirp’s acoustic transmission protocol has settings that are optimised for use in conjunction with industry-standard encryption to encapsulate secure data payloads, giving the benefits of frictionless broadcast transmission with the confidence of trusted encryption standards.
- Communicate with old, legacy equipment: Legacy devices with audio capabilities can suddenly communicate with your wider network simply using their speakers. Equipment without native audio can still transmit data simply by connecting some simple audio-capable companion device.
Example use cases
Alerting and mass broadcasting
Equipping workforces and equipment with sound-enabled devices allows for the transmission of data, instructions or alerts on a mass scale within industrial sites.
For example, a technician could configure or update thousands of sound-enabled devices on a factory floor or in a machine room simply by broadcasting streams of sound through a centrally located speaker or computer, a roaming robot, or even via existing audio infrastructure like a PA system. It should be noted that some PA systems do not support ultrasonic frequencies, so an audible-range implementation would be required.
Other possible scenarios include setting a batch job within a cloud service to automatically broadcast updates to a swarm of devices, or emergency en-masse systems shutdown.
The operational time and cost savings of this sound-based method can be large, particularly where the devices were formerly configured individually or in small batches.
Location tracking, access and authentication
Sound can be used as part of a multi-step personnel authentication process for access-controlled areas or systems.
In addition, within the multiple zones typical of industrial sites, sound can be used to detect and track the location of personnel with sound-enabled devices through sonic ‘beacons’. This can be achieved through audible or inaudible ultrasonic protocols.
Sending data-over-sound enables efficient and frictionless communication with legacy equipment or with equipment located in RF-restricted areas.
In some industrial areas where use of RF networking technologies can be restricted, data-over-sound can be used to record the data onto tablet applications and send the data to a conveniently located listening terminal or microphone. Indeed, if the equipment itself is capable of using sound, then it can transfer the data seamlessly over the air to the technician’s device without the need for manual input.
In situations where for security reasons it is undesirable to provide a direct network connection to equipment, for example to avoid the risk of unauthorised access from outside, ‘listen-only’ connectivity enabling equipment to report back can be created using sound technology, but still maintain a secure air gap with the network.
New networking technologies and capabilities brought by the Internet of Things promise to deliver considerable operational and financial benefit to industrial organisations. However, legacy infrastructure not capable of being networked, or regulatory restrictions on the use of RF technologies mean many companies cannot fully embrace the IoT revolution and thus will only benefit partially.
Data-over-sound technology can provide a seamless, scalable and cost-effective solution to overcome these challenges and we believe sound is a key technology that will help industrial organisations capture the full value of the IoT.
Not only can data-over-sound technology be used to facilitate simple and frictionless communication between offline equipment, it can also complement and extend existing network infrastructures by creating wireless, data-over-sound links between individual offline devices and your wider network.
For more information please follow the link below or see chirp at booth 258 at the IoT Tech Expo Global 2017.