When developing a new product, you can choose from a wide variety of wireless protocols. There are good and bad points to each option. Intended purpose is crucial. This article compares and contrasts Bluetooth Classic, Bluetooth Low-Energy (BLE), and WiFi Direct, the three most common short-range wireless technologies.
The Need for Speed
WiFi Direct is a great option if you need to transfer data quickly between devices. WiFi Direct is more popular, yet few people actually know what it is. But things are starting to change. Access points are required for consistent WiFi connectivity. Therefore, the access point is necessary for any kind of data transfer between gadgets. With WiFi Direct, you don’t need an access point to enjoy the speed benefits of WiFi. There is the option for direct data transmission, much like with Bluetooth.
The maximum data transfer rate with WiFi Direct is roughly ten times that of Bluetooth Classic. For this reason, a high-definition video streaming capability is essential for any product that relies on wireless connectivity. You will almost certainly need to provide WiFi Direct connectivity as Bluetooth will not be fast enough.
On the opposite end of the spectrum is Bluetooth Low-Energy (also known as Bluetooth Smart), which is around two to three times as slow as Bluetooth Classic and twenty to thirty times as slow as WiFi Direct. Common applications include the transmission of sensor values (temperature, acceleration, etc.) or GPS coordinates, both of which require only a modest amount of bandwidth.
Bluetooth Classic is typically used in situations where steady data transmission is required, such as while streaming audio. In contrast to BLE, which is built for brief, rare bursts of data, Bluetooth Classic is designed for continuous data transmission, such as in a streaming application.
Still, BLE can be used for music streaming, albeit not as well as Bluetooth Classic. If you need a Bluetooth LE stack with audio streaming capabilities, for instance, Searan LLC, a vendor of Bluetooth stacks, may build one for you.
Transmission Range
WiFi Direct’s maximum range is roughly 200 feet, making it inferior to that of both Classic and Low-Energy Bluetooth. The increased transmission power used by WiFi Direct is what allows for its greater range.
Due to the higher transmission power, however, a small battery would drain considerably more quickly than when using either Bluetooth standard.
But hold for a second… reality isn’t always so straightforward. It’s not always the case.To begin, not all Bluetooth transmitters are created equal. As was previously indicated, the typical range of a class 2 transmitter used by Bluetooth goods is about 50 feet. However, a class 1 transmitter, with a range of around 300 feet, is also an option.However, the increased transmission power has the same negative impact on battery life as WiFi Direct.
To further extend the Bluetooth’s range, a range extender circuit can be used (mostly consisting of a highly sensitive receiver). As an illustration, Bluegiga, a provider of Bluetooth modules, provides a long-range BLE module (BLE121LR) with a range of up to about 1,500 feet. In addition, they provide a module (WT41) that extends the range of Bluetooth Classic devices to up to 3,000 feet!
Another exception exists. Bluetooth (even the Low-Energy version) can, in some cases, achieve a greater transmission range than WiFi Direct while still consuming very little power. Mesh networking, a fantastic technology, makes this possible.
In most cases, a direct connection between two devices is required for data transfer from point A to point C. However, using mesh networking, information can be relayed from node A to node C via node B. If two devices A and C can be twice as far apart if device B is located in the middle of the two. This is because gadget B serves as a relay, or signal amplifier, of sorts. This concept can be developed further to enable a vast network of distant, interconnected, low-power devices. Actually, mesh may support as many as 65,000 connected devices.
In 2014, CSR, a leading manufacturer of Bluetooth microchips, began shipping Bluetooth Low-Energy chips that supported mesh networking. Until now, no other chip manufacturer has provided mesh with BLE. However, I don’t think that will last for very long.
You can use either Bluetooth Classic or have a custom Bluetooth stack designed to set up a mesh network with other chips. I am aware that Searan, a provider of Bluetooth stacks, can implement mesh networking into their Bluetooth stacks.
Power / Battery Life / Battery size
Power consumption increases in tandem with an increase in speed and direct transmission range, leading to a shorter battery life. Consequently, power consumption is crucial if the duration or size of the battery is a key feature of your product.
In terms of power consumption, Bluetooth Low-Power (BLE) is unrivaled. Its original intent was to power Internet of Things gadgets with a single, tiny watch battery. One watch battery can power a BLE device for up to two years. The primary reason this is possible is that these goods are intended for infrequent transmission. To give just one example, a BLE device might only send data once a minute for just one second. This means that 59 out of 60 minutes, or 98.3 percent of the time, the gadget is not in use.
Compatibility
Bluetooth Classic is a viable option to consider if backwards compatibility with older smartphones is essential to your product’s success. Only the most recent smartphones have compatibility for Bluetooth Low Energy (BLE) and WiFi Direct, however all devices support Bluetooth Classic.
Best of Two Worlds: Bluetooth Dual-Mode
Depending on the use case, Bluetooth Classic or Bluetooth Low Energy may be the superior choice.To save power, you may favor Bluetooth Low-Energy, but you may also wish to support older smartphones.
Bluetooth Dual-Mode could be the finest option. You can utilize the power-efficient BLE mode to talk to newer phones, while switching to the more traditional “Classic” mode allows you to connect with older devices. Dual-mode Bluetooth solutions are available from the vast majority of Bluetooth chip and module manufacturers.
Security
The three different wireless standards all provide a safe and reliable connection. While Bluetooth (both Classic and LE) only use 128-bit encryption, WiFi uses 256-bit encryption. Bluetooth’s level of security is usually adequate, however if security is paramount for your product, WiFi Direct may be preferable.
Summary
There are always costs and benefits to consider when developing an engineering solution.The truth is that there is no one “best” solution.Prioritize the criteria that will have the most impact on your product. This could be easy or hard to do.If speed is your only concern, then the decision is simple.Or if you’re more worried about how long your battery will last, the decision is easy.However, if you value speed and energy efficiency equally, your options expand.
The most difficult part of developing a product is determining which features are essential.Nothing is ever easy in the realm of product development, so get used to it. If it were simple, every business would be as prosperous as Apple.
