Wireless systems (Radio Frequency) are everywhere and they are here to stay. The advancements of wireless technologies have enabled much of the connected world we experience today. And it would be great to leverage the existing technology for your product, but the problems are many between different standards, geographical locations and cost.
Thanks to a few brilliant minds over the course of the last hundred years or so, wireless technologies have become ubiquitous, but that hardly means they have become easy. Yes, there are many options out there that make things ‘easy’, but those easy things come at a cost which involves compromises on cost and/or capability.
If they say, “Hardware is hard”, then “RF is FM” is freaking magic
- Define requirements
What do you need the wireless component of your system to do? There are scores of protocols and technologies out there for wireless devices. Most are familiar with the standard ones like Bluetooth and Wi-Fi, but even in each of those there are many components. Also, the standard ones are only worth it, usually, if you need to communicate with other existing devices. If you are creating your own system, and you don’t need to talk to phones or other networks, then a proprietary network can be a large cost savings.
Range and battery life are other requirements that define which wireless system to use. These two are usually at odds with each other. Even when you don’t have battery life issues, there are maximum output power limitations that will affect range capability.
- Pick a protocol
As stated above, a key requirement is to define what other devices you’ll want to communicate with. These are divided into two categories, proprietary and standardized. Standards are great because you can talk to common and existing devices. However, they can cost more to implement and you usually have to pay a fee to use them. Proprietary protocols are great too, as you can choose components that fit your requirements. If designed properly, proprietary protocols can be as secure or more secure than standard ones as well. It all depends on what features are more important in your application.
- Determine volume
Almost all engineering design tasks are haunted by the volume question. Final product cost can almost always be driven down with volume. Of course, the catch is that while new products are being developed, the number of units that will be sold is mostly a guess at best. All the market research in the world can lead the best and the worst companies to the wrong conclusions. Take the best guess you can, be conservative, then be more conservative, and start there. Once the market is validated, more engineering can always (and more justifiably so) be put into the product to reduce production costs.
One of the most common ways to reduce upfront costs when developing a wireless product is to utilize a module. Sure they cost about 2 – 10 times the cost of the raw components, but they can save $10K to $300K in development and compliance costs. For instance, it may make sense to use a Bluetooth radio system module for up to a few thousand units. A cellular radio system module may be cost effective up to 50K units.
- Choose a Country of Operation
Yep, where you operate a radio system matters. Radio (wireless) emissions are regulated throughout the world (FCC in the USA) and the rules change everywhere. Luckily, there are some common bands or frequencies that can be used throughout the world (thanks to the microwave oven). The most common is 2.4GHz; this is where Bluetooth and Wi-Fi operate. However, these frequencies aren’t the best for long distance communications. 900Mhz (ISM) is a band that is used in the USA for high power and longer range communications. However, this same band is not legal in Europe and only parts are legal in other countries. It can get complicated and these are just the open or public radio bands. There are myriads of bands that are used for government, police, air traffic and maritime uses.
Keep in mind also that these regulations in various countries require compliance. This means they must be tested by an independent lab that states that your device works properly, follows the rules, and plays well with others. Compliance is a significant cost and is one of the major up-front cost savings when using a pre-certified module.
- Specify
This is the hard work where the rubber hits the road. You need to write down your requirements and be prepared to make compromises. Items like range, capability, and overall system operation need to be carefully thought out, then validated with an engineer. We are here to help you do this. Check out our blog at 5 Tips for Writing Your Specification for Product Development for help writing your specification document.
Creating or adding wireless communication to a product is a complex task, but with the right help it can be a fairly deterministic process. Carefully thinking about all of the parameters and requirements from a business and technical perspective is key to getting the right radio system designed and developed. Also, the radio system is just part of your product design. For more information about designing your electronic system, check out our e-Book below.