Editing Bluetooth (section)

=== Bluetooth 2.0 + EDR ===
This version of the Bluetooth Core Specification was released before 2005. The main difference is the introduction of an Enhanced Data Rate (EDR) for faster [[Bit rate|data transfer]]. The data rate of EDR is 3{{nbsp}}Mbit/s, although the maximum data transfer rate (allowing for inter-packet time and acknowledgements) is 2.1{{nbsp}}Mbit/s.<ref name="Guy Kewney" /> EDR uses a combination of [[Gaussian frequency-shift keying|GFSK]] and [[phase-shift keying]] modulation (PSK) with two variants, π/4-[[DQPSK]] and 8-[[DPSK]].<ref name="bluetooth_specs">{{cite web
|url=http://www.bluetooth.org/docman/handlers/DownloadDoc.ashx?doc_id=40560&ei=25GiT8L3CuTa0QGnmqDVDA&usg=AFQjCNGXY5pm4Tkju1KGs4dYRJLtd03FEg
|title=Specification Documents
|publisher=Bluetooth SIG
|access-date=3 May 2012
|archive-date=23 December 2018
|archive-url=https://web.archive.org/web/20181223163507/https://www.bluetooth.org/docman/handlers/DownloadDoc.ashx?doc_id=40560&ei=25GiT8L3CuTa0QGnmqDVDA&usg=AFQjCNGXY5pm4Tkju1KGs4dYRJLtd03FEg
|url-status=live
}}</ref> EDR can provide a lower power consumption through a reduced [[duty cycle]].

The specification is published as ''Bluetooth v2.0 + EDR'', which implies that EDR is an optional feature. Aside from EDR, the v2.0 specification contains other minor improvements, and products may claim compliance to "Bluetooth v2.0" without supporting the higher data rate. At least one commercial device states "Bluetooth v2.0 without EDR" on its data sheet.<ref>{{cite web
|url=http://www.europe.htc.com/z/pdf/products/1766_TyTN_LFLT_OUT.PDF
|archive-url=https://web.archive.org/web/20061012113727/http://www.europe.htc.com/z/pdf/products/1766_TyTN_LFLT_OUT.PDF
|url-status=dead
|archive-date=12 October 2006
|title=HTC TyTN Specification
|publisher=HTC
|access-date=4 February 2008
}}</ref>