Bluetooth or Wi-Fi: Which Is Best for Your Project?

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When you’re creating a connected product, it’s important to choose the right wireless technology. For most products and applications, wireless connectivity is a defining part of the user experience. So, you’ll want to understand your options before you commit to a path.

The basics of wireless connectivity

Wi-Fi is a trademarked name used to refer to devices that employ the 802.11 IEEE standards. Wi-Fi’s primary function was to replace the physical backbone of the internet—the wired infrastructure required for wired networking connections (Ethernet)—with an untethered, wireless connection. Since the initial standard was introduced in 1997, Wi-Fi data rates have improved from 1-2 Mbps up to 10.5 Gbps for the emerging 802.11ax standard.

Bluetooth technology originated in the 1990s as well, but its primary function was device-to-device (or point-to-point) protocol for securely sharing data between devices in close proximity. The wireless connection is often limited to two devices, although this is changing with the release of the latest revision. Unlike Wi-Fi, Bluetooth was primarily designed for low power consumption, with a short range that’s ideal for small battery-operated mobile devices.

Which wireless communication protocol is most suitable for your product? Let’s examine some of the strengths and weaknesses of the two technologies.

Wi-Fi vs. Bluetooth: A maker’s guide

Each of these popular technologies has its own pros and cons. The protocol you choose depends on your product’s needs in these key areas:

Range

  • Because Wi-Fi technology was built to replace Ethernet technology in local area networks (LANs), it offers superior range compared to Bluetooth. A typical Wi-Fi signal can be accessed up to 100 meters or 320 feet away from a wireless access point. 
  • The Bluetooth standard is intended to exchange data over short distances, usually between personal mobile devices. It’s great for connecting pairs of Bluetooth devices like smartphones, headsets and peripherals. However, its connectivity quickly fades over distances greater than 10 meters or 30 feet. 

Bandwidth

  • A true networking protocol, Wi-Fi has been under continuous development since its inception. The most recent version of the IEEE 802.11ax standard is expected to deliver connectivity at multi-gigabit speeds, making it ideal for rich media apps like video, and the best choice in multiple-user environments. 
  • Bluetooth was designed to be a simple way to connect two devices with minimal power consumption. However, the technology is generally much slower and offers less bandwidth than Wi-Fi. For example, Bluetooth is suitable for audio applications but cannot handle the massive bandwidth of streaming video. 

Affordability

  • Wi-Fi solutions (i.e., transceivers and antennas) are generally more expensive than Bluetooth solutions, which can be an important factor if overall cost is top of mind. B
  • luetooth solutions are generally much less costly than Wi-Fi. A typical Bluetooth transceiver integrated circuit (IC) costs roughly $1, compared to $5-$7 for a Wi-Fi IC. 

Power efficiency

  • Wi-Fi technology is a power hog, which is a big issue for mobile applications. It was originally built to connect office devices like desktop PCs, printers and networking devices, which are not battery-operated. 
  • Bluetooth was developed with low-power applications in mind. This enables Bluetooth devices to enjoy much longer battery life—from 10 to 100 times longer battery life than in similar devices that use Wi-Fi. 

Security

  • Wi-Fi can accommodate a wide range of security measures. Security protocols are inherent to the 802.11 standard (i.e., WEP, WPA, WPA2) and security certification programs that secure communications between devices. In addition, network-based encryption techniques, such as virtual private networks (VPN), can provide resilient data protections. 
  • The Bluetooth standard also specifies security protocols that must be implemented in order for devices to establish a secure connection. These include the user acknowledgment of connecting devices via the “pairing” procedure and various options for encrypted data exchange. 

Design Effort

  • Wi-Fi has traditionally been complex and required fairly significant efforts in regards to both hardware and firmware developments. With the increased focus on IoT devices, Wi-Fi solutions have evolved very quickly and solutions are now available that provide Wi-Fi connectivity with minimal effort and at lower costs. 
  • Bluetooth, from a hardware perspective, is not as complex as typical Wi-Fi solutions. However, the firmware communications stack requires detailed configuration that can require in-depth knowledge of the Bluetooth stack.

Consider the certification and licensing process

It’s important to think about certification and licensing when choosing a wireless standard. This entire process can require substantial time and resources so consider this factor when deciding on shipping dates for your eventual backers.

In order to sell your wireless communications product in nearly any country, you are required to have your product tested and comply with the local radio-frequency (RF) emissions standards. In the U.S., the Federal Communications Commission (FCC) sets and manages these regulations. To have your product certified, you would contract an accredited laboratory to perform the required testing and then submit formal filing to the appropriate Telecommunications Certification Body (TCB).

To place the Wi-Fi or Bluetooth logos on your product, you need to obtain a license from the respective organization. For the Wi-Fi trademark, you’ll need to become a member of the Wi-Fi Alliance along with having your product tested through an authorized test laboratory. Bluetooth is actually a trademark of the Bluetooth Special Interest Group (SIG), so you’ll need to join the group and complete the Bluetooth qualification process before you can use it.

Do you want to make or buy?

Another aspect that you must carefully evaluate is which option is more beneficial to your development scenario: make a chip-down solution or buy a modular solution.

A chip-down solution involves designing the complete wireless circuit, including selecting the IC and supporting circuitry. It also involves the design of RF circuits. This can require specialized engineering skills and test equipment to implement an optimized solution. A chip-down solution also requires extensive testing through both the certification and licensing processes no matter which wireless technology you choose. As a result, a chip-down solution can require substantial expenses up front, adding significant risk to the launching of your product.

Modular solutions are readily available for both Wi-Fi and Bluetooth. Pre-certified modules significantly reduce the testing and paperwork required for certification and licensing processes. Also, designing with modules reduces the need for specialized RF skills and equipment. As a result, you’ll reduce your upfront costs greatly and, most importantly, mitigate much of your risk. The downside is that modules typically cost more per unit than their chip-down counterparts.

A good strategy can be to use modules for initial development and low volume production. This is often the time when funds are tight and your success depends on lowering risk. Once your product is launched and you’re starting to think about mass production, consider lowering costs and investing in riskier developments.

—Bob Merriman