This document discusses the basic procedures for establishing a Bluetooth connection between devices. It describes the inquiry and paging processes, elements of connection establishment like link establishment and service discovery. It also discusses Bluetooth protocols like RFCOMM, L2CAP, and pairing, as well as power saving modes like sniff, hold, and park. The goal is to provide an overview of how two or more Bluetooth devices initiate and complete a connection to enable secure data transfer.

1. Prof. Neeraj Bhargava
Pramod Singh Rathore
Department of Computer Science
School of Engineering & System Sciences,
MDS University Ajmer, Rajasthan, India
1

2. Bluetooth ensures reliable data transfer
when devices are connected.
 A connection is required for secure data
transfer.
This section describes e basic procedures to
be followed by two or more Bluetooth
devices to start a connection between
themselves.

3.  Inquiry:-The device on reaching a new
environment would automatically initiated an
inquiry are within its range.
 Paging:- The device will invoke a baseband
procedure called paging.
This results in synchronization of the device with
the access point.
Following are the Elements of Connection Establishment Procedure

4.  Link establishment:-This is the sequence of activity
perform by link manager of the paging device to
establish a physical link.
 Service discovery:-The LMP will use the
SDP(service discovery protocol) to discover what
services are available from the access point.
 RFCOMM channel:- Depending on the need of the
email application an RFCOMM or other channel will
be created over the L2CAP channel.

5.  L2CAP channel:-With information obtained
from SDP the device will create an L2CAP channel
to the access point.
 PPP:-This link will allow the user to login to his
email account.
 Data transfer:-In this data is transfered.
All above are the Elements of Connection Establishment Procedure

6.  RFCOMM (Radio Frequency
Communication)
 Pairing
 L2CAP(Logical Link ControlAdaption
Protocol)

7.  The Bluetooth protocol RFCOMM is a simple set of
transport protocols, made on top of the L2CAP protocol,
providing emulated RS-232 serial ports.
 RFCOMM is sometimes called ”serial port emulation”.
The Bluetooth ”serial port profile” is based on this
protocol.
 RFCOMM provides a simple reliable data stream to the
user, similar to TCP.
 RFCOMM provides a simple reliable data stream to the
user, similar to TCP.

8.  Service Discovery Protocol(S.D.P)
 Service Discovery Server(S.D.S)
 Service Discovery Database(S.D.D.B)
Following are the Some Services of RFCOMM…

9. The service discovery profile defines the
protocols and procedures that shall be used
by a service discovery application on
a device to locate services in
other Bluetooth-enabled devices using
the Bluetooth Service Discovery Protocol
(SDP).

10. A specific Service Discovery protocol is
needed in the Bluetooth environment, as the
set of services that are available changes
dynamically based on the RF proximity of
devices in motion different from service
discovery in traditional network-based
environments.

11.  In order that devices can connect easily and quickly, a scheme known as
Bluetooth pairing may be used. Once Bluetooth pairing has occurred two
devices may communicate with each other.
 Bluetooth pairing is generally initiated manually by a device user. The
Bluetooth link for the device is made visible to other devices. They may
then be paired.
 The Bluetooth pairing process is typically triggered automatically the first
time a device receives a connection request from a device with which it is
not yet paired. In order that Bluetooth pairing may occur, a password has
to be exchanged between the two devices.
 This password or "Passkey" as it is more correctly termed is a code shared
by both Bluetooth devices. It is used to ensure that both users have agreed
to pair with each other.

12. Device
1
Device
2
Pass Key Authentication
Data
Receive
Pass Key
Confirmed
Authenticated
Data Transfer

13.  L2CAP is used within the Bluetooth protocol stack. It
passes packets to either the Host Controller Interface
(HCI) or on a hostless system.
 L2CAP is used to communicate over the host ACL(A-
synch Connection Link) link. Its connection is
established after the ACL link has been set up.

14. Network
Authenticate
Dead
Establish
Terminate

15.  Active mode:- This is the regular connected
mode,where the device is actively transmitting
or receiving data.
 Sniff mode:-This is a power-saving mode,where
the device is less active.
 It’ll sleep and only listen for transmissions at a
set interval.

16.  Hold mode:-Hold mode is a temporary,power-
saving mode where a device sleeps for a defined
period and then returns back to active mode
when that interval has passed.
The master can command a slave device to hold.
 Park mode:- Park is the deepest of sleep modes.
A master can command a slave to “park” and
that slave will become inactive until the master
tells it to wake back up.

17. STANDBY
PageDATA
Tx/Rx
Active
SniffHoldPark
Inquiry

18. Thank You…!