The Internet of Things (IoT), is changing the world. By 2025, there will be almost 22 billion IoT devices. The expansion of internet connectivity to everyday objects can transform industries and result in huge cost savings. How can non-internet-enabled objects gain connectivity through wireless sensors?
IoT can be made possible by wireless sensors. Wireless sensors can be used by individuals and companies to enable a variety of smart applications. Wireless sensors are the foundation of IoT. They connect homes and cities to create smart infrastructure. Anyone who plans to use IoT technology in the future must understand how wireless sensor technology works. Let’s take a look at wireless sensors and the emerging standards for wireless sensors. And finally, let’s see what their role will be in the future.
What is a wireless sensor?
A wireless sensor can be described as a device that gathers sensory information and detects changes in the local environment. Wireless sensors can be used to detect changes in the environment, such as temperature sensors, movement sensors, and liquid sensors. Wireless sensors aren’t capable of processing large amounts of data locally and they require very little power. If the best wireless technology is used, it can last for years. Sensors can be easily supported over low-speed networks because they transmit very little data.
Wireless sensors can be combined to monitor the environmental conditions in a given area. Wireless sensor networks are composed of many sensors distributed in different areas that communicate via wireless connections. The sensors in a network share data through nodes that consolidate information at the gateway or where each sensor connects to the gateway directly provided it has the required range. Gateways are bridges that connect local sensors with the internet. They can also be used as wireless access points and routers.
Also read: What are the Types of Sensors and Actuators in IoT
Types of Wireless Network Topologies
There are a few topologies in that wireless sensor networks can be set up. The star and mesh topologies are the most common to support wireless sensor technology.
1. Star Topologies
Star topologies refer to those where every node is connected directly to a central hub, gateway, or other devices. This arrangement allows nodes to send information to one gateway which then relays the messages to the destination. It is possible for gateways to share information with multiple nodes at once, making it easier to scale networks.
Nodes don’t exchange data directly with each other, so there are fewer point-to-point links. Star topologies are easy to set up, configure, manage, and maintain. New nodes need only to be connected to one central location. Star topologies can be used to enable data transfer between multiple wireless sensors.
Star topologies are dependent entirely on the wireless connection between the sensor’s central hub and the sensor. Because there is no way to repeat the signal or “hop” it, this can limit the range. Scaling depends on whether the gateway can support additional nodes.
2. Mesh Topologies
Mesh topologies place data transfer responsibility on the nodes of the network, rather than relying on a single hub. Mesh topologies function as routers and can transmit information to other nodes. Because data can travel on many paths to reach the gateway, connectivity problems at some junctures are less likely.
Mesh networks can present a variety of problems. Mesh networks are more complex and often require overly complex protocols to create the network and relay data. Mesh networks are more energy-intensive than star topologies because some nodes must be on to relay information. This is another major drawback. Mesh networks are often used to solve a lack of range. This makes it more difficult to justify the high upfront investment.
Traditional Wireless Sensor Protocols
Many wireless protocols allow for connectivity between sensors.
WiFi (or “wireless fidelity”), is a widely-used Local Area Network technology. It transmits information using two primary frequencies: 2.4GHz and 5.GHz. Wi-Fi networks are capable of transferring large data packets at high speeds over medium distances. Wi-Fi’s primary benefit is its availability in almost all homes and businesses. This makes it an extremely convenient network.
Wi-Fi signals are not able to penetrate walls and consume more power than other wireless sensor protocols due to the high data overhead. The Wi-Fi keys are managed in the router. This means that any change to a key could easily cause sensors to be disconnected. There is no easy way to update these keys. Televisions, laptops, and smartphones are all examples of these devices. Displays allow users to change the key easily, but simple sensors don’t have such an interface and must be provisioned to do so. Wi-Fi sensors are therefore challenged with reliability and long-term management.
IoT sensors do not typically require Wi-Fi bandwidth. It is therefore less suitable for simpler sensors. Because there are so many high-bandwidth devices competing to use the same Wi-Fi channels for streaming video, audio, and other complex data transfers, there can be lots of interference which can cause problems for other devices that need to send simple messages.
Bluetooth low energy (or BLE) is a low-power protocol designed to allow periodic low data rates wireless communication over short distances. BLE is not to be confused with Bluetooth technology. This is the wireless sensor that transmits small packets of information. This technology is an affordable alternative to Wi-Fi and doesn’t require nearly as much power. BLE can also be used at 2.4GHz. However, this protocol has a limited range and is not able to penetrate walls. It also faces interference from other devices using 2.4GHz.
Zigbee is a low-power wireless alternative to Bluetooth and WiFi for more than a decade and has been a popular choice for wireless sensors that do not require a lot of bandwidth. Zigbee is based on the IEEE 802.15.4 standard. It relies on mesh networks for data transmission. Zigbee is used often to enable smart homes with many low-power devices.
Zigbee is able to support 65,000+ nodes in one network, which is a significant advantage over Z-Wave. Zigbee has one drawback. Some nodes must remain “on” in order to relay information, as described in the wireless topologies section. There are also increased infrastructure costs because routers are required to extend the range. Zigbee, DigiMesh, and other mesh networks are expensive “band-aids”, which can be used to improve RF performance, range, interference avoidance, and range.
Also read: What is Cellular IoT A Complete Guide
Z-Wave is a wireless protocol specifically designed for smart home applications. Zensys developed the Z-Wave technology. It runs on the 900MHz frequency band which is less noisy, and thus avoids major interference issues. Z-Wave mesh networks are limited in their ability to support wireless sensors. They also have the same limitations as mesh networks previously mentioned. The cost of the technology is also increased by the need for users to sign a licensing agreement at Silicon Laboratories.
The primary purpose of Z-Wave sensors being built is to be compatible with existing Z-Wave devices. Z-Wave has been extensively used in the home security industry because it allows bi-directional communication to endpoints via an encrypted channel. Traditional home security protocols are unencrypted and one-way. They don’t work well with applications like door locks.
LPWAN Standards for Wireless Sensors
A new class of wireless standards has emerged from the desire to connect small devices like sensors to the Internet. Also, the vision of connecting billions of everyday objects all over the globe is LPWANs. LPWANs, a particular class of radio technology that is used to transmit small amounts of data over long distances, are called radio technologies.
LPWAN networks use less power than connected wireless sensors and are easier to access. LPWANs allow end users to trade bandwidth for a greater range. This is ideal for wireless sensors that are simple. LPWAN solutions can be more economical, allowing companies to achieve positive ROIs on their IoT applications.
LoRa® (an abbreviation for “long range”) is a well-known wireless standard that has greater bandwidth than Sigfox. LoRa uses a unique modulation scheme called Chirp Spread Spectrum, which allows for excellent link margins and can reach signals below the RF noise floor. LoRa sensors are able to transmit large data packets over long distances in noisy environments. LoRa networks can be used in either public LoRaWAN base stations or private gateways. This makes it especially useful for wireless sensors located in remote areas that may not have public access.
LoRaWAN gateways are connected to a cloud-based LoRaWAN server. The data is then pushed to the application.
Benefits of Wireless Sensor Technology and IoT
Wireless sensor technology is a great option for IoT deployments.
- Improving service company responsiveness and effectiveness: A wireless sensor can be described as a device that gathers sensory information and detects changes in the local environment wireless water leak sensors can be a benefit to both plumbing and insurance companies. These sensors could be installed at apartment buildings and condo complexes by plumbing service providers so they are alerted if there is a leak. To minimize damage from accidental flooding, insurance companies could also install leak sensors in homes.
- Supporting patient healthcare via real-time monitoring: At senior care facilities have wireless push buttons that can act as mobile PERS devices and alert staff when assistance is required. These facilities can use wireless window or door sensors to detect if residents leave their rooms.
- Enabling smarter and better product management: Grocery shops and retailers can protect their assets using different wireless sensors placed throughout their premises. Wireless air temperature sensors allow facility managers to monitor temperature levels in refrigeration units and ensure that perishables remain safe.
- Improving safety and security in industrial settings: Fleet managers at car dealerships can install wireless acceleration-based motion sensors on their vehicles. This will allow them to receive notifications when cars are moving at night. This is a sign that there may be theft. Warehouse supervisors can use wireless air sensors to calculate heat indexes and ensure employees are safe.
- Preservation and maintenance of fragile artwork: Preservation specialists can install wireless humidity sensors in museums and galleries to adjust the air quality to preserve artifacts and artwork. Optic sensors can also be used to detect light levels and ensure guests have the best viewing experience.
- Protecting and fixing local infrastructure fast: Utility companies have the ability to install probes at high temperatures on utility poles in order to detect transformer problems. They could also use tilt sensors to configure sensors to alert maintenance personnel when poles are tilted or struck by vehicles.
Improve Your Daily Life
These are just some examples of wireless sensors that will allow IoT applications to be integrated into our everyday lives. We will see more innovation in different industries as well as other useful applications of the technology over time.