| Bluetooth 2.0 |
This version, specified on 10th November 2004
is backward-compatible with 1.1. The main enhancement is the introduction of an
EDR of 3.0 Mbit/s. This has the following effects:
- Three times faster transmission speed�up to 10 times in certain cases
(up to 2.1 Mbit/s).
- Lower power consumption through a reduced duty cycle.
- Simplification of multi-link scenarios due to more available bandwidth.
The practical data transfer rate is 2.1 megabits per second and the basic
signalling rate is about 3 megabits per second.
The "Bluetooth 2.0 + EDR" specification given at the Bluetooth Special
InterestGroup (SIG) includes EDR and there is no specification "Bluetooth 2.0" as
used by many vendors. The HTC TyTN pocket PC phone, shows "Bluetooth 2.0 without
EDR" on its data sheet and another
source states Bluetooth 2.0 without EDR is equivalent to version 1.2 with
additional bug fixes. In many
cases it is not clear whether a product claiming to support "Bluetooth 2.0"
actually supports the EDR higher transfer rate.
Bluetooth 2.1
Bluetooth Core Specification Version 2.1 , is fully backward-compatible with
1.1, and was adopted by the Bluetooth SIG
on August 1, 2007. This
specification includes the following features:
- Extended inquiry response: provides more information during the inquiry
procedure to allow better filtering of devices before connection. This
information includes the name of the device, a list of services the device
supports, as well as other information like the time of day, and pairing
information.
- Sniff subrating: reduces the power consumption when devices are in the
sniff low-power mode, especially on links with asymmetric data flows. Human
interface devices (HID) are expected to benefit the most, with mouse and
keyboard devices increasing the battery life by a factor of 3 to 10.
- Encryption Pause Resume: enables an encryption key to be refreshed,
enabling much stronger encryption for connections that stay up for longer
than 23.3 hours (one Bluetooth day).
- Secure Simple Pairing: radically improves the pairing experience for
Bluetooth devices, while increasing the use and strength of security. It is
expected that this feature will significantly increase the use of Bluetooth.
- NFC cooperation: automatic creation of secure Bluetooth connections when
NFC radio interface is also available. For example, a headset should be
paired with a Bluetooth 2.1 phone including NFC just by bringing the two
devices close to each other (a few centimeters). Another example is
automatic uploading of photos from a mobile phone or camera to a digital
picture frame just by bringing the phone or camera close to the frame
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