WiFi Technologies: Costs, Considerations, and Comparisons

Wireless connectivity is now becoming a standard offering as competitive interfaces give applications the “Without Wires” port. Whether it be in addition to existing ports or the primary interface, wireless is now the mainstream connection. Wired interfaces are very cost effective and offer the user a type of “guaranteed connection”. However, the advent of mobile and handheld products wireless technology has primed markets for countless additional technologies. The formulas for success haven’t changed: time to market and cost still influence engineer’s decisions. Another major consideration is an engineer’s RF expertise. Hence the introduction of wireless modules is a solution to these and other problems faced by those considering designing wireless capabilities into a new or existing project.

Years ago wireless LANs (802.11) were introduced into PCs. The added feature allowed a user to connect with flexible locations and took the market by storm. However, most people were not ready to trade in their existing laptop or desktop, so add-on modules and boards for the purpose of making PCs wireless became the popular option. USB, PMCIA, or PCI were used as the backend interfaces for PCs and ranged in cost from $50 to $100. As the market progressed, technology advanced and 802.11 continued to pick up momentum, prices spiraled down. The cost of an 802.11 port on a PC soon became unidentifiable and the wireless port feature became standard. Today it is hard to find a PC without an 802.11 port.

Why WiFI Modules Are a Great Solution for Embedded Designs

Now the volume of PCs and the wireless interface they offered is more understandable. But what about the growing markets that were forming during this time? Could it be those products would require ports without wires too? Could it be a competitive issue that focused on end to end connectivity? Yes, of course! And that is where we are today. 

So what’s the difference? The RF wireless part of the design is done. Now engineers who are not RF designers or have limited RF experience do not have to spend time with the wireless front end. Modules alleviate concerns surrounding WiFi certifications; those thousands of dollars spent on testing WIFI are borne by the module manufacturer. The technology is proven. All of this is a contribution to the time to market and cost fundamentals. The back end interface in the OEM world is where digital engineers do their best work. It’s not just plugging the module in, though. In the PC world, drivers and software adhere to standards for the different versions of operating systems for which they were designed. In the OEM world, engineers may be using different operating systems, maybe proprietary, so knowledge of networking and communications is required.

The Process of WiFi Selection: 10 Key Considerations

1. Transmit (TX) power. Typical lower cost modules range between <10-12dBm. Midrange power is approximately 15-16dBm and higher range is 18-20dBm. Expect to pay more for higher power.

2. Does the module come with the appropriate regulatory certifications for your application? Examples of regulatory certifications include FCC (USA), IC (Canada), ETSI (Europe), C-TICK (Australia), and Telec (Japan), among others.

3. How does the module perform across different environments (e.g. over temperature)?

4. What is the back end interface? Serial, RS232, SPI, USB, or 8/16/32 bit CPU?

5. What drivers will you need?

6. What standby power and low power features does the module have? 

7. What frequency band will you be using? Do you require operation at wider frequencies such as 5.8GHz to cover 802.11a/b/g, or 2.4GHz for 802.11b/g/n?

8. Ease of integration. What surface mount packaging do you need?

9. Development environment, including evaluation tools and development platforms.

10. Does the module include an antenna or antenna connector, or will you need to include an external antenna in your application?

Remember that time to market, reduced development costs, easy deployment, global certifications, proven electronic design, flexible alternatives from suppliers, and overall reduction in risk all play into the selection of WiFi modules. All of these considerations are crucial to the end application and vary cost of each module.

If you’d like to discuss your wireless needs, please call Symmetry Electronics at (310) 536-6190, or contact us online.