The internet has moved from sitting on our desk tops to watching over our warehouses, riding in our truck beds, and floating in our underwater farms. Every day, the worldwide IIoT (industrial internet of things) adds new devices that deliver remote monitoring and automated actions via real time data collection and communication. Globally, 20 billion devices are on the Internet of Things, with some experts forecasting an increase to 30 billion connections by the end of 2018.
However, one size telecommunication network cannot fit all. IIoT devices have a range of bandwidth needs and power requirements; moreover, they may be mobile or operating in degraded conditions. There is a best fit cellular or a wireless network solution.
IoT Communication Considerations
When choosing an IoT telecommunication method, data needs determine the outcome. Let’s unpack a few considerations:
How much data do I need to transmit?
Bandwidth is how much data can travel over the internet. The data travels over bands, or channels when referring to wireless area networks (WANs). Think of it as a road: whereas a wide band network is an interstate with many lanes, a narrow band network is a two-lane road. By volume, the interstate can transfer more cars back and forth than the two-lane road. If an IIoT device transmits a high volume of data, it needs a wide band solution. If it is a low volume data application, a narrow band solution will suffice.
How quickly and how often do I need to transmit data?
While bandwidth describes the maximum amount of data that can pass through, throughput is the volume of data that actually does pass through. The data transmission speed is called the data rate. Throughput is primarily determined by a device’s components. However, it is limited by bandwidth: if the anticipated throughput is greater than the bandwidth, the data rate will be slow. Besides low bandwidth, other external factors can affect the data rate, such as channel competition or distance from the network source.
In what environment will I need to transmit data?
The operating conditions of an IIoT device will affect its capabilities. WANs are negatively affected by distance and degraded conditions, such as power surges. If there is low physical security, a WAN may have higher security risks. Devices in non-mobile, stable and controlled environments will have flexibility in their communication protocols.
How much battery do I have?
Large IIoT devices can accommodate larger batteries, but smaller devices are limited. Batteries onboard must be efficient. Whether the device operates on a cellular network or a WAN, the technology must not drain the power source. Using something beyond range or with insufficient bandwidth can drastically reduce battery life.
Cellular Networks for IIoT
Cellular uses a system of towers to create an area-wide network using radio frequency (RF) signals and wires that carry information. Devices integrated with cellular are configured to send and receive RF signals to the tower. The tower then sends it along a physical network to a switching station, which directs the data to the destination, whether a landline or other cellular device. Because these towers communicate on physical lines, the network area can be nationwide or larger. Both wide band and narrow band technologies serve IIoT markets. The term band refers to the “lane” that the data travels over.
Within wide band, the most common choice of network is LTE, which stands for “long term evolution.” It is 4G, or “fourth generation,” cellular technology. 5G technology is expected to release in 2018 and it will feature optimized bandwidth resulting in high data rate speeds. Two subtypes of 4G suit IIoT applications well: CAT1 and M1. They’re good for long-distance communication and reliability. They can also be more expensive.
This subtype works best for applications that require continuous reporting everywhere, especially mobile. For example, personal mobile phones rely on this standard. Using this technology, a device will constantly attempt to send data, even searching for less busy bands, until the procedure is completed. This can put high pressure on a specific provider’s bands and draw more power, relative to other cellular tech. Thus, it can be expensive and require frequent charging or more durable battery storage.
This channel is for devices that don’t need to continuously report. Instead, devices on this channel are pre-programmed to transmit data at specific times. These may be intervals of every 5 minutes or once a day during low-traffic periods. As a result, signals on this channel experience reduced competition, which mitigates device network searches. IIoT devices relying on M1 cellular tech do not consume as much power as their CAT1 peers.
Although narrow band technology has been used previously, such as for pagers, its repurposing is the newest IoT cellular offering. T-Mobile NarrowBand-IoT will be the first North American plan, starting June 2018.
NB-IoT is a 4G technology that provides small, consistent data streams at low cost. It has the lowest power requirements of cellular technology. Unlike other cellular tech, devices on NB-IoT cannot be mobile; moreover, they cannot transmit voice data. Ideal applications for this standard are smart city sensors.
Wide Area Networks for IIoT
Unlike cellular technology, WANs are localized networks for which devices must be specifically configured using a system of nodes and routers. Although they also transmit information via RF signals, they use different frequency channels and rely on different physical technology to create their networks. Most WANs have a shorter distance than cellular, but they support a higher throughput and bandwidth. For non-mobile applications, WANs can be a strong viable alternative.
Wi-Fi configured IIoT devices are best for short-range, multi-vendor operation. This network is ideal for localized, in-building IoT networks, such as warehouse management, because it relies on a centralized access point, such as a router. Wi-Fi is also inexpensive given the low cost of the infrastructure. However, Wi-Fi channels can get crowded, which can introduce latency. Variations of Wi-Fi standards, such as HEW and HaLow, can be more suited to IIoT applications. They are easy to implement, but they do have a high energy requirement
Mesh networking also provides short-range wireless networking. It is less centralized than Wi-Fi because each device in the IoT network functions as a wireless node. This distributed architecture increases the difficulty of implementation and the risk of inefficient networking. Unlike Wi-Fi, this network does not require an ISP. Mesh networks can be scaled up, but that will not increase their small range. They have a high throughput like Wi-Fi but consume less power. A market example of a mesh network is the home connectivity technology Zigbee.
LPWANs are long-range, low-power wide area networks. Much like NB-IoT, this technology was designed with IoT in mind. Unlike other WANs, this has a very high range, which makes it suitable for long-distance applications. However, it has a low throughput, which means long-range sensor applications, such as a smart city use, would work but a data-heavy remote monitoring system would not. One Rwandan conservation park tracks rhinos using the Semtech-proprietary LoRa LPWAN.
As the future millions of IIoT devices enter the market, connecting them to their best fit communication service will be key to ensuring the technology’s integrity. Regardless of industry, there is a networking solution that will be cost-effective and meet data requirements. If you find this information helpful and would like to proceed with your own IoT strategy, feel free to contact us. We would love to help.