While this is a match between competitors of different ages, Bluetooth 4.0 being the more advanced standard, is also worth noting that 3.1 has some great features, which made it probably the most used version at the moment.
The difference between Bluetooth 3.1 and 4.0
Bluetooth is a wireless technology that was created by Ericsson back in 1994 and is meant for short distances only. It works around the 2.4 GHz spectrum and uses a frequency-hopping mechanism for modulation. Available in applications such as headsets, intercoms, cellphones and even consoles, Bluetooth devices have spread rapidly through the years. With more than 7 versions developed until the moment, it’s time you found what separates the most advanced at the moment.
Bluetooth 3.1
Bluetooth 3.1 is a small variation of the core 3.0 standard. Officially known as Bluetooth 3.0+HS, it provides transfers speed of up to 24 Mbit/s by actually using the 802.11 wireless to carry information (Bluetooth is only used for setting up the connection). Besides coming with a superior rate of transfer, Bluetooth 3.1 comes with a reliable channel with transmission and flow control, which can be disabled for applications that rely on low latency conversations and need to transfer a small amount of data. In terms of power, Bluetooth 3.1 uses a new power scheme to handle certain situations, basing on the strength of the signal. For example, when the user places the phone inside the pocket, on the opposite side of the handset, the power consumed by the Bluetooth antenna will be set to maximum to ensure connectivity.
Bluetooth 4.0
Bluetooth 4.0 includes the classical Bluetooth, high speed and low energy protocols. Born in June 30, 2010, this version blends the advanced principles of conventional Wi-Fi with the classic knowledge of Bluetooth technology. This is mostly seen in the following features:
Low-energy consumption: the new power consumption protocol aims very low with energy for applications up to 50 meters away. In a few words, it consumes only a fraction of the power purged by the classic standard and not by sacrificing the signal strength, but altering the duty cycles design. It is optimized for small burst of data, and a continuous use will actually make it consume more power. More reliable on multi-point connections More secure Faster
In conclusion, always go for the highest number when it comes to Bluetooth. The last version is more reliable, faster and usually more power-friendly.