Improved Time to Connect for Bluetooth

Document type: Conference Papers
Peer reviewed: Yes
Author(s): Lennart Isaksson, Markus Fiedler
Title: Improved Time to Connect for Bluetooth
Conference name: 9th WSEAS International Conference on Communications
Year: 2005
City: Athens
Organization: Blekinge Institute of Technology
Department: School of Engineering - Dept. of Telecommunication Systems (Sektionen för teknik – avd. för telekommunikationssystem)
School of Engineering S- 372 25 Ronneby
+46 455 38 50 00
Authors e-mail:,
Language: English
Abstract: Bluetooth has from its beginning used Frequency Hopping (FH) from version 1.0A to the current version 1.2. The so-called selection box uses a complex scheme to calculate the next correct frequency in time. This makes transmissions between Bluetooth devices both robust and secure. Several attempts have been carried out to improve the time to connect, due to the relatively high time to connect given by the Bluetooth specification. Many have not fully understood the FH for Bluetooth and have therefore suggested sub-optimized solutions to improve the time to connect. In this paper, a presentation of the problem that causes the poor time to connect performance is given. This knowledge is needed for an improvement of the time to connect for Bluetooth. To accomplish a reduction of the time to connect by a factor of 100, three main parameters have to be changed: First, the A-train and B-train should be switched directly after each other. Second, the phase should be switched faster, which is based on the clock. Finally, a reduction of the random backoff parameter needs to be considered. These changes, together with other parameters, like time out values, have to be changed/reduced accordingly. Together with these changed parameters a simulation of the time to connect for Bluetooth is presented.
Subject: Telecommunications\General
Keywords: Bluetooth, Frequency Hopping