Wireless Connectivity and RF Module Selection for IoT Devices

Wireless technology has become the dominant choice in designing and developing devices for all electronic categories. For the development minded engineer, it is a requirement to understand the different wireless technologies and protocols that have evolved and are making their presence known in the industry. We are going to define and look into several key wireless technologies often referred to as RF (Radio Frequency) protocols that are offered as modules to design and development teams.

Here is a list of protocols and standards that are presently and will allow the choice of the device design that meets your needs. In some cases, some of these protocols can be combined together to allow for the ability to communicate together.

1. WiFi – Dual Band 2.4GHz/5GHz


a. WiFi is the preferred choice to connect devices together and open up the ability for such devices to go through the router and link to the internet.
b. Dual Band is prevalent now in all WiFi devices developed on the routers so as to easier connect IoT devices that presently use 2.4GHz.
c. Smart TVs are all incorporating Dual band in order to meet the demand of streaming Apps such as Netflix, Amazon, Roku and Google
d. 2.4GHz vs 5GHz frequency is a matter of choice that with dual band implemented this protocol automatically selects which frequency and channel that provides the cleanest and clearest communication between devices.
e. The trade-off between 2.4GHz and 5GHz isn’t hard to understand at all:

i. 2.4GHz gives you more range but a weaker signal
ii. 5GHz offers a stronger signal which also results in a faster signal and inherently is cleaner airspace than 2.4GHz.
iii. 5GHz frequency cannot travel as far around and penetrate through as many walls as 2.4 GHz can.

1. Simply put the wireless waves attenuate faster at higher frequencies, so signal strength distance wise is not as far.

f. Dual Band provides for the best an optimal solution when using WiFi as all of this is automatically selected as devices hook up to the router.

2. BLE (Bluetooth Low Energy) 5.x

a. Bluetooth 5.x added the capability from 4.x to create mesh profiles using BLE.

i. Each device can pass the information forward to other Bluetooth Low Energy devices creating a “mesh” effect.

1. Playing multitude of audio BT devices synchronized together.
2. Simple command and control like switching off an entire building of lights from a single smartphone

b. Bluetooth 5.x creates MESH (Mesh Profiles) .

i. Via MMDL (Mesh models) – for application layer definitions and creating stored Mesh profiles of all the connected devices.

c. BLE 5.x also is downward compatible to all versions of the BT protocol.

i. What used to be called BT Smart protocol is now part of BLE 5.x

3. BLE 4.x

a. Introduced the ability to provide Low Power/Energy consumption for devices
b. Savings of Power provided for the introduction of Audio devices that were with BT Wireless connectivity
c. Mesh profile was not implemented in versions 4.x and below.
d. For certain projects and cost consideration BLE 4.x is still a choice decided by what is really needed for such IoT devices.

i. For single pairing between phones and IoT device, it’s still a choice to consider.

4. Zigbee


a. Zigbee Alliance provides for products to be built specifically for IoT devices.

i. Goal is to enable all objects to connect and interact with each other.

b. Zigbee 3.0 their present release

i. Provides an increases choice and flexibility for users and developers, and delivers the confidence that products and services will all work together through standardization of its’ protocol.

c. Zigbee 3.0, which enhances the IEEE 802.15.4 standard by adding mesh network and security layers along with an application framework and to become a full stack, low-power certifiable, interoperable Zigbee solution.

i. Allows cross-band communication across 2.4GHz and sub-GHz bands with multi PHY support
ii. Enables global operation in the 2.4GHz frequency band according to IEEE 802.15.4
iii. Enables regional operation in the 915Mhz and 868Mhz
iv. Incorporates power saving mechanisms for all device classes, plus support for battery-less devices
v. Features security key generation mechanism, as well as discovery and pairing mechanism with full application confirmation
vi. Sub-GHz channels transmission ranges up to 1km

d. 2.4 GHz ISM band usage ensures license free product deployment worldwide

5. SigFox


a. SigFox is one of the latest premier companies setting itself apart to become a protocol to connect all IoT devices under one global communication net.

i. One of the forefront leaders in NB-IoT (Narrow Band – IoT) protocol.
ii. Looking to define how all the billions of IoT devices can communicate under a single protocol.

b. SigFox radio protocol is designed to operate in license-free frequency bands. In each country’s ISM.

i. These frequency bands are under control of local regulations and have defined technical constraints for using the spectrum but remains unlicensed.

c. SigFox has defined its newest “Radio Configurations” that define radio parameter values that comply with global local regulations.
d. SigFox radio protocol is named 3D-UNB.

i. 3D stands for triple diversity, i.e. diversity in time, in frequency and in space.
ii. UNB stands for Ultra Narrow Band.
iii. 3D-UNB protocol is designed to operate even if some objects are uplink only.

1. Radio engineers are strongly encouraged to pay close attention to receiver design.
2. These characteristics have a direct impact on the overall performance of downlink communication.

6. LoRa

a. Very similar to SigFox in creating a global protocol and ability to address the total mesh of using the NB-IoT protocol

i. Protocol is designed and developed through a cooperation with many companies who form the LoRa Alliance.

b. The main specification of the LoRa protocol is the LoRaWAN specification

i. Simply defined and built upon the Low Power Wide Area Network (LPWAN) protocol.

c. LoRaWan is designed to wirelessly connect battery operated IoT devices to the internet.

i. Protocol covers connectivity from regional local areas to national and global networks.

d. LoRa goal is to target key IoT requirements together in their alliance structure.

i. Includes bi-directional communication,
ii. End-to-end security
iii. Mobility and localization services to connect a multi-tude IoT devices seamlessly.

7. Sub-GHz

a. A newly formed group of companies are focusing on the ISM bands that are below the 1GHz frequency.
b. The design and development of IoT devices supported by the all license-free ISM frequency bands specifically in the 868 to 928 MHz, 433 MHz, and 315 MHz.
c. The design of such products provides for low power consumption, distance coverage and low cost for products that target a wide range of proprietary wireless industrial and consumer applications.

Choosing the right Wireless Connectivity for your device

All of these protocols listed above utilize the ISM frequency centered mainly around 2.4 GHz. WiFi does now include dual band at 5GHz unlicensed. It should be understood that within every ISM frequency are also channels. These channels help separate the data communication going between devices that use the same frequency to allow for less data collision and BER (Bit Error Rate). WiFi and BLE are the most popular protocol and specs used within the wireless community. The other protocols are gaining popularity with the whole evolution of smart devices and the IoT category industry expanding at such a rapid pace.

What this basically means as a designer and developer is that you can design with these protocols and not have to register with the FCC on creating such devices like the latest IoT devices coming to the market. This is why companies like SigFox and LoRa Alliance want to provide you with their protocol specifications that can help unite all devices globally. As a designer choose which of the 7 different protocols to use, it’s really about what your electronic device will work and you should consider power consumption. The above 7 mentioned protocols are already being used in the market and there is a steady improvement in all of these protocols. At TechDesign we can provide guidance and reference to which such protocol works the best for your device.

GPlus IoT RF Modules Help You Choose the Right Protocol

Here at TechDesign, the company that can help in choosing the right protocol for you is GPLUS. GPlus IoT Technology Inc. is a technology service company, which provides the integration of various software and hardware technology and facilitates the establishment of different types of wireless RF networks as well as cloud services via on-line or even off-line in many ways. With emphasis on also R&D, GPLUS is a strong high-tech enterprise yielding strong results. GPLUS products include health care, home automation, smart agriculture, eTag system and wearable devices in sports.

GPlus IoT RF modules can be found on TechDesign eMarket

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