Radio Layer

a. Radio layer defined the carrier frequencies and output power

b. Bluetooth uses 2.4 GHZ license free band.

c. Frequency hopping and TDD (time division duplex) is used for transmission with fast hopping rate of 1600 hops/s.

d. It uses 79 hop carriers equally spaced with 1 MHz.

e. Gaussian FSK used for modulation.

Baseband Layer

a. Baseband layer performs frequency hopping to avoid interference and to access the medium.

b. Defines physical links and many packet formats.

c. It controls: o Device Addressing

o Channel control through paging and inquiry methods

o Power saving operations

o Flow control and synchronization among Bluetooth devices.

Link Manager Protocol (LMP)

a. The Link Manager protocol manages various aspects of the radio link between master and slave.

b. The following functions are covered by LMP:

o Authentication, pairing and encryption

o Synchronization

o Capability negotiation

o QoS negotiation

o Power control

o Link Supervision

o State and transmission mode change

Logical Link Control and Adaptation Layer Protocol (L2CAP)

• L2CAP is layered over the Baseband Protocol and resides in the data link layer.

• L2CAP provides:

i. Connection-oriented and connectionless data services to upper layer protocols with protocol multiplexing capability.

ii. Segmentation and reassembly operation.

iii. Group abstractions.

• L2CAP provides three different types of logical channels that are transported via ACL link between master and slave, these are:

i. Connectionless used for broadcast

ii. Connection-oriented for data transfer with QoS flow specification.

iii. Signaling used to exchange signaling messages between L2CAP entities.

Host Controller Interface (HCI)

a. The HCI provides a command interface to the baseband controller and link manager.

b. It provides access to hardware status and control registers.

c. Essentially this interface provides a uniform method of accessing the Bluetooth baseband capabilities.

d. The HCI exists across 3 sections, The Host, Transport Layer, and Host Controller. Each of the sections has a different role to play in HCI system.

e. HCI defines the set of functions of a Bluetooth module that are accessible to the host and its application.

f. HCI can be seen as a software/hardware boundary.

RFCOMM

a. The RFCOMM protocol provides emulation of serial ports over the L2CAP protocol.

b. It is a cable replacement protocol that provides a serial line interface to all the applications.

c. The protocol is based on the ETSI standard TS 07.10.

d. It supports multiple serial ports over a single physical channel.

Service Discovery Protocol (SDP)

a. The service discovery protocol helps the applications to discover which services are available and to determine the characteristics of those available services.

b. SDP defines only the discovery of services, not about their usage.

c. New service is discovered as follows:

o Client sends a request to search for an interested service.

o Then the server responds to the client with the list of available services that match to the client’s criteria.

o The client uses the list to retrieve additional service attribute for the service of interest.

Profiles

a. Profiles are specifications which describe how Bluetooth should be used in a specific application and thus ensures that all devices from different manufacturers can seamlessly work with one another.

b. There are about a dozen profiles:Generic Access, Serial Port, Dial up Networking, FAX, Headset, LAN, Access Point, Generic Object Exchange (OBEX), File Transfer, Object Push, Synchronization, Cordless Telephony, and Intercom.

c. The profile concept is used to decrease the risk of interoperability problems between different manufacturers’ products. Telephony Control Protocol Specification Binary (TCS-BIN)

a. To define call control signaling for the establishment of voice and data calls between Bluetooth devices TCS-BIN describes a binary, packet-based, bit-oriented protocol.

a. AT: Attention sequence

b. OBEX: Object Exchange

c. TCS BIN: Telephony control protocol specification – binary

d. BNEP: Bluetooth network encapsulation protocol

e. SDP: Service discovery protocol

f. RFCOMM: Radio frequency comm.