What is IoT connectivity? 8 types explained

How does IoT connectivity work?

There are three fundamental elements of IoT connectivity: communication protocol, network architecture, or type, and computing hub, a destination for IoT data and control signals.

Communication protocol

Protocols are the rules that devices follow to communicate with each other and the greater network. Wi-Fi and Bluetooth are common and popular protocols, while niche protocols include NB-IoT and LoRaWAN. A network typically supports more than one protocol, each with its own advantages and disadvantages. Protocols are selected based on the intended use case or device needs.

Network architecture

The network architecture carries IoT data using the selected protocol, connecting IoT devices to one another and the computing hub. The four principal network types are cellular, local area network (LAN), low-power wide area network (LPWAN) and mesh. Each brings a unique mix of range, bandwidth, power and cost.

Consequently, businesses must choose network architectures to meet very specific environmental or IoT deployment needs. For example, a cellular network provides long range and high bandwidth with moderate power consumption, while a LAN network, using Wi-Fi protocol, typically provides short range, low-power demands with high bandwidth.

Computing hub

A computing hub is the focal point for IoT connectivity. It collects IoT data and sends management or control signals to IoT devices. It also provides resources needed to collect, store, process and analyze IoT data sets. An IoT computing hub is often an IoT gateway located at the edge — close to both IoT devices and their generated data. Sometimes serving as a local data center, computing hubs are more commonly deployed today as a public cloud provider or service.

Why is it important to choose the right type of IoT connectivity?

Connectivity directly affects any IoT project's parameters. Proper connectivity lets an enterprise align IoT technologies with a business goal to achieve the most desirable outcome. Improper connectivity means higher costs, unexpected limitations and even poor device endurance – all threats to IoT project success. There are several reasons to pinpoint the specific type of IoT connectivity required. They include:

• Range, or scope. To save money and ensure suitable performance, connectivity must match the deployment's scale and needs. For example, using advanced 5G IoT devices for a smart building project or Wi-Fi devices to support an entire metropolitan area are improper choices.
• Power and bandwidth performance. Beyond scope, suitability involves practical deployment factors, such as power usage and network bandwidth. Some IoT devices cater to low-power, low-bandwidth uses. Others supply significant bandwidth but require more power. Connectivity must match the bandwidth and power needs of the use case. For example, an IoT project needs low power, and, due to infrequent data transmission, low bandwidth uses NB-IoT connectivity. By comparison, an IoT project requiring high bandwidth with moderate power consumption chooses Wi-Fi IoT devices.
• Scalability. Often starting as a basic proof of concept endeavor to achieve a simple business goal, IoT projects sometimes evolve into much larger and more complex IoT environments. Scalability ensures bandwidth, power, range and device support issues remain manageable during growth.
• Reliability. IoT devices sometimes fail. Networks, when overburdened, drop valuable data that can't be recovered. Therefore, select suitable IoT devices for the identified task that provide comprehensive management features and reliable long-term operation under all expected conditions. Otherwise, expect expensive, time-consuming – and avoidable – maintenance.
• Security. As data security becomes an ever-greater problem, management must select IoT devices and build IoT environments employing advanced security features as standard practice. For example, IoT devices must require unique authentication credentials and never allow default credentials for normal operation, employing encryption to prevent data snooping. Also, effective firmware upgrades must meet these new security threats, providing a well-designed management interface that monitors device health and performance across the entire IoT environment.
• Cost. IoT devices vary widely in performance, capabilities and subsequent cost. Matching IoT device connectivity to business goals is the best way to achieve cost efficiency. For example, using 5G IoT devices for a small, building-wide project is typically a waste of money.

How to choose the right type of IoT connectivity

IoT connectivity requires choosing from among a set of clearly defined and often measurable factors. They include the following:

• Bandwidth. Consider how much data IoT devices need to transmit. Devices intended to generate significant amounts of data in real time require high-bandwidth connectivity and a network architecture to match. Many IoT devices, all producing data simultaneously, also need a suitable network architecture.
• Latency. A traditional network operates well in high-latency situations when delays in data transmission do not affect the data's value. IoT devices often demand low-latency connectivity features to ensure data is transmitted without delay. Mission-critical, real-time IoT projects need low-latency connectivity such as 5G.
• Management. Well-designed management platforms track IoT device health, monitor performance, set configuration parameters and deliver firmware updates. Although management platforms have little impact on the choice of connectivity, connectivity is a factor for some actions, such as firmware updates. For example, low-bandwidth device connectivity typically needs significant time to deploy a firmware update.
• Mobility and location. Device mobility and location affect connectivity choices. For example, a mobile device subject to unpredictable or variable operational conditions, such as interference or obstructions, demands technology, such as 5G, more resilient to those conditions.
• Power. Although stationary IoT devices sometimes draw power through wired interfaces, such as Power over Ethernet (PoE), remote or mobile IoT devices require battery power. Consider IoT device power requirements and establish a comprehensive maintenance schedule that includes preemptive battery replacement.
• Range, or coverage. Consider the area IoT devices need to cover. Device connectivity—and the network that connects those devices—must provide adequate range. For example, a basic Bluetooth IoT device transmits data about 30 feet and requires a Bluetooth network access point within that range.
• Scalability. IoT environments often grow and evolve over time. Select a connectivity option that easily accommodates future IoT devices without compromising bandwidth or latency.
• Security. Authentication and encryption must be default security features. Even low-priority or non-critical IoT projects need strong data security features that don't compromise performance.
• Cost. Finally, consider the procurement, deployment and ongoing operational costs of any IoT device and its connectivity. For example, a 5G IoT device is more expensive to obtain and operate than a Wi-Fi or Bluetooth IoT device.

Types of IoT connectivity

Ultimately, there are many connectivity options for IoT devices. Each connectivity type offers its own unique mix of bandwidth, latency, mobility, range, scalability, security, reliability and cost. The most popular types of IoT connectivity currently include the following:

• Bluetooth. This is a short-range, low-power, burstable wireless connection between IoT devices and nearby hubs, such as wearable devices connected to smartphones. The limited range is ideal for consumer or room-sized IoT tasks but is ill-suited for building-scale or larger IoT deployments.
• Low-power (LP) cellular. An alternative to traditional cellular IoT connectivity, LPWAN connectivity, including LTE-M, LoRaWAN and NB-IoT, is designed specifically to connect huge numbers of devices across large environments. LP cellular offers slower data speeds than traditional cellular connectivity but uses very low power, extending battery life.
• Mesh. Mesh connectivity, such as Zigbee, builds peer-to-peer networks where IoT devices relay data between the individual devices. This extends the effective range and overcomes common interference from obstacles, so it's well suited to small deployments in building automation. However, mesh connectivity’s complexity typically demands a communication hub.
• Satellite. Global Navigation Satellite System is a broad term describing a chain of satellites used for global positioning and navigation. These worldwide connections manage tasks such as asset tracking and remote assistance location. In effect, the IoT device receives positioning data, then transmits that data using other connectivity options.
• Traditional cellular. A reliable, long-range, moderate-power wireless connection, it uses cellular towers and services to exchange data and enable sensors and actuators to operate remotely. A variety of cellular connectivity standards currently exist, including 2G, 3G, 4G, 5G and LTECat-1. Each offers a mix of bandwidth and latency, but all require some level of cellular service – costly for most large IoT deployments.
• Radio frequency identification (RFID). RFID is a proven technology used to identify and track items with tags that transmit identifying data to nearby readers. Though commonly applied to tasks from inventory to access control, RFID is limited in its uses, exchanges very little data and requires a reader in proximity to the tags. Although commonly listed as an IoT connectivity option, RFID is a niche option at best.
• Wi-Fi. Wi-Fi offers secure, short-range, high-bandwidth connectivity, enabling local area IoT devices to communicate with a nearby Wi-Fi router, ensuring internet access. This provides more range and flexibility than Bluetooth and makes Wi-Fi a good choice for local tasks and stationary IoT devices in building automation. However, Wi-Fi needs moderate amounts of power, shortening the battery life of connected devices.
• Wired Ethernet. Traditional Ethernet provides a reliable, wired, high-bandwidth connection for demanding, typically stationary, IoT devices, though it's not suited for most vehicles or other mobile uses. PoE technology powers IoT devices over the Ethernet cable, eliminating battery replacement regimens.

Challenges of IoT connectivity

Although IoT technology challenges are not particularly unique in IT, the massive array of IoT devices exchanging an ever-growing volume of critical real-time data demands creative and sophisticated solutions. Common challenges of IoT connectivity include the following:

• Interoperability or compatibility. IoT devices must communicate with a central hub – and often each other – but they employ various protocols and network architectures. Differences in supported protocols sometimes create interoperability problems between devices and systems.
• Performance. Compromise and foresight must guide the choice of connectivity type. Management's IoT selection handles many independent devices and supports them as their data volumes skyrocket – real-time, high-resolution camera data, for example. Networks must be designed to start small and expand substantially in time, always balancing cost and performance while growing.
• Power. Although wired networks such as PoE offer continuous power, mobile and remote IoT deployments typically depend on limited power from batteries or energy harvesting techniques such as solar. IoT environments often emphasize energy efficiency and effective power management. As a rule, IoT devices that transmit more data more often – and across a greater range – use more power.
• Range. IoT depends on exchanging data across established areas, whether small or large. This requires connectivity that supports the necessary range while maintaining performance. As IoT deployments grow, it’s more difficult to maintain proper signal strength, coverage area and subsequent data quality.
• Reliability. There are two issues here: device reliability and data reliability. Devices are deployed in mobile, remote and often hostile environments. They fail. Effective monitoring and maintenance protocols are needed to oversee IoT device fleets. In addition, real-world operation of IoT devices and networks sometimes results in lost data, including dropped packets, highlighting the difficulties in maintaining adequate data quality.
• Scalability. IoT deployments tend to gain complexity over time. The IoT environment must readily support more devices, heavier data loads and more complex infrastructures, all while continuing real-time performance. The worst IoT outcome is scrapping one IoT deployment and starting another from scratch because the current IoT environment cannot scale.
• Security. IoT security is improving, but the onus remains on the enterprise to ensure IoT deployments and data employ consistent and manageable security techniques, such as strong encryption and authentication with a centralized IoT device management system. Failing to ensure adequate security leads to malicious attacks, data breaches and inappropriate device and data access.

Trends in IoT connectivity

A handful of trends have emerged and have begun to evolve across IoT connectivity, led by:

• 5G cellular growth. 5G cellular connectivity offers low latency and high bandwidth and is well-suited for complex IoT tasks. Also, current 5G devices offer longer battery life and greater reliability.
• Low-power cellular growth. Beyond conventional 5G, LP cellular technologies such as LTE-M and NB-IoT now offer low-power, wide-area connectivity alternatives where 5G range and data throughput capabilities are unnecessary or unsupported.
• Satellite communication use. Where cellular connectivity is unavailable, satellite connectivity – Starlink, for instance – serves remote or underserved locations, often complementing other conventional technologies such as cellular.
• Edge computing growth. Edge computing stores and processes data closer to IoT devices and the data's origin. This means shorter-range, lower-power IoT devices handle mobile or autonomous tasks, including driverless cars.
• AI and IoT. AI, now integrated into IoT devices, delivers more autonomy in device operation, data processing, data analytics and decision-making in real time. It often couples with other growth areas, such as edge computing, to build distinct platforms.
• Blockchain. Immutable ledger technologies such as blockchain are now integrated into IoT devices and systems. This bolsters security and enhances trust in environments where data is shared.

Stephen J. Bigelow, senior technology editor at TechTarget, has more than 30 years of technical writing experience in the PC and technology industry.