The WiFi revolution has taken connectivity solutions to the next level. There is a major shift towards utilizing the capabilities of WLAN/IEEE802.11 on various non-conventional products, such as coffee makers, toothbrushes, and thermostats, etc. We can control these consumer products through an app using a smartphone and other internet-connected devices. The key benefit of using internet-connected devices, such as smartphones is that they allow us to develop applications very quickly. The end consumers will have an integrated interface with the WiFi module devices. Some recent examples of this include music players, video cameras, video games, GPS devices, and televisions.
There are so many applications of the wireless module in different industries. Another recent application driving wireless module is the IoT (Internet-of-Things), where more and more customer devices use WiFi modules for connectivity.
To establish a wireless internet connection, product manufacturers must learn how they should pair their products with wireless capability. Using a prepackaged wireless module is a straightforward method of adding wireless capability. This approach simplifies the connectivity process, but it also has some challenges.
In this article, we will discuss the design cycle along with the possible pitfalls one may encounter. But before anything else, let’s take a look at the different applications of a WiFi module.
WiFi (wireless fidelity) is a prevalent technology that serves the role of establishing internet connections for electronic devices. It enables these devices to exchange data or establish an internet connection wirelessly through radiofrequency.
Specifically, WiFi refers to the interoperability capability with independent WLAN devices. On the other hand, WLAN denotes devices that are compliant with one or even more standards of IEE 802.11. There are different meanings of these terms. But, WLAN devices must be compatible with WiFi.
The use of WiFi technology is so broad in many industries. We can see its application in an assortment of industrial, consumer, commercial, and scientific applications. Countless devices use WiFi, and all of them can establish a wireless connection to network resources through wireless network access points. Here are the most common applications of a WiFi module:
Smart Energy and Utility: Smart meters, EV-chargers, light controls, and thermostats
Consumer Electronics: Toys, home security, internet radio, and remote control
Fitness, Medical, and Healthcare: Fitness equipment, patient monitors, and real-time location devices
Retail: Digital remote signage, wire-free price tags, and POS (point of sale) terminals
Industrial Controls: M2M communication, security systems, wireless controller, and chemical sensors
Above are the most common areas where wireless modules are used for wireless connectivity of devices. WiFi modules have also become an integral part of remote device management for asset and location tracking, code update, and automotive applications.
Wireless modules are functional units and you can only run them after embedding them into the system. Therefore, you must consider both hardware and software aspects when looking for a WiFi module for different applications.
The WiFi module hardware comprises two central parts; an app host processor and the WiFi chip. If you need a wireless module for a more advanced WiFi application, you can choose a module from the top manufacturers of wireless modules. Make sure to look for a high-end module with an embedded processor core and signal chain combination.
The host processor of the application has an external or internal flash, RAM, and ROM. Various Internet of Things is accessible which allows an assortment of applications. Analog computers, SCIs (serial-communication interfaces), crystal oscillators, debug interfaces, DAC, and ADC, etc. are a few examples.
Some applications require specialized software for delivering the security, manageability, and trouble-free operations that consumers need. The WiFi software normally includes an integrated security supplicant 802.11, fully-featured monitoring and management utility, and the device driver.
When doing your research about the right WiFi module, you will find many modules and solutions on the market. The module makers or vendors normally categories wireless modules by several parameters, such as packaging type, certification, RF band, range, and data rate, etc. Several parametric filters can help you refine search results as per the specifications that you are after.
There are a few significant factors you need to consider while evaluating WiFi technologies. Those include power requirements, range, and data rate. Enhancing the spectrum efficiency and data throughput are key drivers for the research on wireless communication for the last two decades.
It results in complex modulation techniques and channel coding with more power and higher cost for signal processing. 802.11ac and 802.11n have the greater data throughput advantage when we make a comparison between different WiFi protocols.
On the other side, 802.11b/g is advantageous in terms of power requirements and compatibility. 802.11n offers operation benefits of high data throughput, enhanced link quality, greater range, and it allows for better network utilization.
The 802.11ac WiFi module comes with higher bandwidth support over long ranges by providing two times the bandwidth speed for 600Mb/s through 802.11n. It allows wireless solutions to full today’s high-quality and high capacity real-time mobile application needs, such as voice and video.
Using MIMO technology (multiple antennas) can further improve the range and data rate. However, such extended features require you to spend some extra money by using various antenna structures, increased design complexity of BOM, and using more power.
The market has linked clients including, buildings, home automation, industrial products, M2M (machine-to-machine), M2P (machine-to-person) control and data devices, and sensors. These markets require and are governed by lower data rates and lower power consumption solutions. They have no concern with the bandwidth, but compatibility and the battery life.
For several M2M (machine-to-machine) applications, the b/g supported data rates are sufficient. The 802.11b/g wireless module is ideal to use with an embedded space because b/g is still an ideal choice for low-power, fully WiFi compatible applications.
Apart from the selection of the protocol, there are also a few other tradeoffs. Antenna selection is one example of that. The WiFi antenna comes in two different types, such as directional antenna and Omni-directional antenna.
Omni-directional antennas are advantageous because of their straightforward setup. All you need is to mount these antennas at a higher position. After that, you need no major adjustment. However, it has a tradeoff that it will send signals in every direction and will not concentrate at its source.
On the other hand, the directional antenna is beneficial because it focuses the narrow energy bean in a single direction. Therefore, it will greatly increase the probable distance range you can get the connection over. However, the tradeoff for the directional antenna is that the manual antenna rotation requires additional time via 360-degree for desired hotspot connection.
So many manufacturers want to design M2M (machine-to-machine) devices via the integration of a WiFi module into the products. However, there is a big hurdle for conventional non-wireless manufacturers, like those manufacturing refrigerators and stoves.
The big hurdle is that they don’t have the much-needed RF expertise for building network devices. Luckily, various RF module makers who build and design wireless modules for the M2M embedded market are available. You can get their consultancy during the integration design.
However, relying on a specific RF module maker to get a solution for all RF problems is not a practical decision for product development engineers. The possibility is that there will still be the need for RF consultant support.
Or, you can also hire a specialized test & measurement company for this. Such companies can help you meet specific test requirements for 802.11 specifications. Look for a company that offers an array of solutions to fulfill your specific requirements.
Selecting Parameters
Today, you can choose from various wireless standards according to your requirement. The advantages of wireless connectivity rely on the standard you choose. The recent wireless local area network standards include 802.11 a/b/g/j/n/p/ac/ad,…
All standards have their unique specification needs, and you must consider your tradeoffs, such as power consumption and data rate. The latest coding rates and modulation techniques usually sustain high data rates and are more efficient. However, older rates and methods still have backward compatibility support.
2.4GHz (2.4 – 2.483GHz) – 802.11b/g/n
5GHz (5.15 – 5.725GHz) – 802.11a/h/j/n/ac
5.9GHz (5.85 – 5.9GHz) – 802.11p
Every single range is broken into an array of channels. Different countries have different regulations to allowable channels, max power levels, and allowed users within the above-listed frequency ranges. You can also choose a WiFi module with Dual-Band support.
WiFi networks come with a limited range. It relies on the types and how many routers and/or WAPs (wireless access points) you use. Here are the different factors that decide the range of a wireless device:
The 2.4GHz WiFi frequency block has a little improved range than the 5GHz WiFi frequency block utilized by 802.11ac, 802.11n, and 802.11a.
Lengthy transmission distance and high data rate need high output of transmit power for the wireless module. But, high WiFi power consumption in the device affects the battery life which is a concern. There are local regulations that limit this, like FCC Part15 in the United States.
WiFi supports different performance levels according to the technology standards they support. Every single WiFi standard has a rating about its max theoretical throughput. Practically, the wireless networks data rate practically never meets such theoretical maximums because of the high layer overheads.
The max WiFi module theoretical data rate can be between 1 Mbps/802.11b to 6.75Gbps/802.11ac. High data rates are not always good. Therefore, you should select an appropriate option according to the application.
Microprocessors or microcontrollers are the brains of a wireless module. They provide the finest hardware platform to design wire-free network nodes, combining radio communications and high-performance processing.
Cost is an important selection criterion along with other criteria, such as program size, data memory, peripherals availability, processing speed, and power consumption.
Linux, iPad/iPhone, Android, WinCE, and other embedded programs support. Modern-day WiFi modules allow you to configure wireless network options and security using either tablet/smartphone (Android or iOS-based) or PC (internet browser).
If you require build in your product feature, you can check the level of driver support, management support, and configuration from your wireless module.
The WiFi module size holds significant importance in the selection of the module. It becomes essential when you are adding a product to the compact wireless module. Such devices include almost all portable devices.
Normally, the range of operating temperature for a wireless module is anywhere between -40C to 85C. However, some modern-day commercial Wi-Fi modules do not require verification on the high or low-temperature range.
Even the makers of wireless modules specify their modules as ‘Extended Temperature WiFi”. Typically, such advanced modules have a fan and a miniature heater to maintain the device temperature in different conditions.
There are two packaging types of modules; SMT (Surface mount) and Through-hole packaging. SMT type exhibit more advantages than the Thorough-hole. Approximately 90% of board assemblies use SMT technology due to its added benefits.
The recommended land patterns of PCB for wireless modules are present in the datasheets of manufacturers. The host processor dictates the PCB layers numbers. At least four layers are essential with an 8 or 6 layer PCB layout.
Time-stamping real-time clock, auto wake-up modes, Soft AP support, OTA firmware upgrade, onboard IP/TCP stack, evolution kits, frequency references, user-programmable, receive sensitivity, price, and manufacturer are the other important features and considerations.
Real-time clock for time-stamping, auto-sleep, and auto-wakeup modes, Supports Soft access point, Over the air firmware upgrade, evaluation kits, Onboard TCP/IP stack, Receive Sensitivity, Frequency References, User programmable (I/O), Manufacturer, Price.
You must also check the certification/compliance of the WiFi module you want to buy. Reliable module manufacturers tell their customers about the certification and compliance of their products. It is also important to check the hardware interfaces.
A digital interface can be a serial UART link, SDIO (secure digital), SPI (serial peripheral), or USB. Never invest in a low-quality module just because of its low price.
You can ask us anything related to Wi-Fi modules if you still have any queries.
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