As sensor technology and network capabilities have evolved to meet application needs, the question for organizations considering wide area IoT deployments is no longer if they should be implemented, but how – and in a way that can scale with ease.
Simply having smart sensors deployed in the field and generating data is not enough to guarantee the success of an IoT solution. IoT solutions need the right network supporting them. As you begin to plan and build your IoT solution, you will need to ensure that your network can deliver information securely, reliably, efficiently, and at a price that protects the total cost of ownership (TCO) while meeting the requirements of your application and its users.
When deciding which network is best for your IoT solution, begin by considering three primary factors – power, range and bandwidth.
Consider how you might be powering your IoT network and associated devices. If there is no continuous grid power available or desired, then battery life will be an important factor, especially in remote/hard-to-reach areas or in large-scale deployments with hundreds or thousands of sensors.
Broadcast range affects how far the signal from a sensor must travel before it reaches a network server. Your technology choice impacts how many gateways or access points are required to route the data to its destination; the more hardware you need, the more one-time and recurring costs you or your customer will incur. Also, not all radio frequency (RF) travels and penetrates physical structures equally. Over large areas, the physical terrain or presence of obstacles such as thick walls become primary considerations
If your application requires the transmission of large amounts of data or payloads at a high bit rate, like audio or video in a smart security network, it will need high bandwidth. If, however, your IoT network is comprised of sensors that simply provide a binary “yes or no” answer or track specific measurements, such as a temperature reading, it can operate at significantly lower bandwidth, reducing overall power consumption.
Your power, range, and bandwidth requirements will inform decisions concerning your connectivity technology. For IoT, there are a number of viable connectivity protocols, each offering advantages and disadvantages for any application.
If your applications must cover a wide area, you should evaluate the two most common long-reach networks: cellular and low-power wide-area networks (LPWAN).
Cellular and LPWAN networks both have their place in IoT, with unique strengths and weaknesses that need to be carefully considered based on your application needs.
As mobile technologies became ubiquitous in both personal and professional contexts, so did the demand for more data at greater speeds. Over time, this led to the development and rapid deployment of 3G, 4G, and now 5G networks around the world. Today, cellular networks cover a vast majority of the world’s population, providing extensive coverage across many global markets. Furthermore, the popularity of cellular networks has created a large ecosystem for vendors, manufacturers, and providers, ensuring continued support of the network for the future. Cellular networks are built to handle massive volumes of traffic, enabling transmission of large data packets such as audio and video – but this comes at a high cost.
As it relates to wide-area applications, cellular network concerns include higher costs, poor battery life, and limited propagation deep indoors and underground, making it a viable option for high bandwidth and power-hungry applications (see Figure 1). Perhaps the largest obstacle for cellular in wide-area applications is the continuous evolution of new protocols. Consider how quickly cellular networks have advanced. 3G, which was once among the most advanced innovations in connectivity, soon advanced to 4G and now 5G, causing 3G networks to be sunset. Each time the previous technology is phased out, field endpoints are orphaned and must be replaced at a significant cost to all involved. Depending on the use case, these costs can be incredibly high.
Low-power wide-area network (LPWAN) technologies have an extensive global footprint, with large-scale use proliferating in cities and enterprises across the globe. LPWAN is a network category defined by two characteristics. The first characteristic is that the network is low power, which means that the network sensors can operate for many years on small, inexpensive batteries. The second characteristic is that the network covers a wide area, which means that it has an operating range with single transmissions often reaching up to 30 miles, depending on the application.
LPWANs work well in situations where small amounts of data need to be sent over wide areas by sensors that will be in place for long periods of time and are well suited for easy field programmability and updateability. In addition to keeping energy-related costs low, these long-lasting batteries are critically important for scaled deployments or use cases where sensors are located in hard-to-reach areas such as underground or deep within buildings or other structures because they greatly reduce the cost of maintaining the entire system.
LPWANs are creating new possibilities for enterprise IoT solutions. To understand why, it is important to understand the network’s technical features.
Compared to traditional cellular networks, LPWANs provide the technical features and operational costs for enterprise IoT applications that need wide-area coverage along with relatively low bandwidth, good battery life, low hardware, and high connection density.
Data transmitted across LPWANs can travel as far as 30 miles, depending on the application, making it ideal for enterprises needing to transmit data across wide geographic areas, such as a large business campus.
Excellent Signal Propagation
Whether sensors are placed on a rooftop, underground, or deep indoors, LPWANs can reliably collect and transmit data from its source to gateways and network servers. The superior range and propagation offered by LPWANs enable enterprises to achieve greater coverage with fewer access points.
Batteries that power LPWAN sensors can last for many years depending upon the environment and application. In some use cases, sensors are programmed to send information and then go to sleep for a prescribed period of time. In others, sensors stay asleep until a prescribed event triggers the sensor to send an alert. The combination of small bit sizes (i.e., simple points of information such as on/off, flow measurement, temperature reading) and intermittent transmissions (as opposed to continuous transmissions) means that sensor batteries can last 10 years or more, depending on the application, without needing to be replaced, ultimately saving costs
High Network Capacity
A single gateway can support thousands of devices and millions of transmissions per day, resulting in simpler deployments and lower infrastructure costs.
LPWANs have been deployed throughout the world for over a decade and power a wide range of enterprise and civic IoT solutions.
Owing in part to these technical features, one of the biggest benefits of LPWANs is that they are the most cost-effective option for wide area IoT solutions.
Not only are the smart sensors themselves designed to operate more cost effectively, but LPWAN connectivity costs are also much lower. Unlike cellular networks and the powerful endpoint devices (e.g., smartphones) they were designed to support, LPWANs are envisioned and designed for low-complexity endpoint devices. The majority of an LPWAN’s computing capability is moved upstream to the cloud. This Network Function Virtualization (NFV) design keeps costs low for endpoint devices, opening up new use cases with new form factors, that are not practical if using higher cost cellular hardware and higher cost cellular connectivity.
Today’s LPWAN modules, the components inside sensors that transmit and/or receive radio signals, are inexpensive and the cost is expected to continue falling over the next several years as the market grows. The low power requirements of an LPWAN sensor also control costs associated with smaller batteries and longer replacement cycles.
Lower Base Station Costs
In contrast to cellular towers, LPWAN gateways are stateless. The sensor is paired to an application in the cloud, so the sensors and gateways do not have to establish a session to communicate. This allows the network to push complex operations to the cloud. As a result, the gateways cost less to deploy in a network. The point to multipoint signaling protocols used by LPWANs can be received by several gateways simultaneously. This, in combination with the excellent coding techniques, provides excellent range and reliability.
LPWANs use unlicensed spectrum, which means operators do not need to spend billions of dollars at FCC auctions to acquire private spectrum. These savings represent very significant cost benefits to operators and end users.
LPWAN sensors are designed to use very little power to gather and transmit data. The battery-powered sensors transmit simple low bit rate responses that require far less power budget than gathering and transmitting large packets of data associated with applications like audio or video. A dense network of LPWAN gateways reduces the distance from a sensor to a gateway, and further reduces the energy requirements for the sensors.
Low Maintenance Costs
Lower power budgets mean that LPWAN sensor batteries can last 10 years or more, depending on the application. Since broad deployments create challenges to servicing a large number of sensors often in difficult to access locations, IoT solutions deployed on an LPWAN reduce not only battery cost but also the maintenance budget associated with replacing batteries and end devices.
These combined cost savings make the TCO for an IoT solution enabled by an LPWAN network far lower than those using competing networks that are designed for high-bandwidth applications, which require frequent maintenance and have device connectivity costs.
Once you determine that an LPWAN is the best way to deploy your wide-area IoT solution, the next step is evaluating which type of LPWAN radio technology is best for your specific application.
To learn more about selecting the right technology for your IoT solution, contact us for a consultation.