A Comparison of Bluetooth and competing technologies

Technologies Bluetooth IrDA HomeRF

What we’ll talk about Purpose and Specifications Communication Protocols and

Network Topology Disadvantages and Advantages in

certain scenarios Application comparison, consumer

criteras, business analysts

Purpose Why Bluetooth?

The Bluetooth specification is a global technology that allows wireless communication and networking between PCs and other portable devices.

Why HomeRF? HomeRF enables different consumer electronic devices to

communicate with each other while providing users with a complete home network solution. Users will be able to dial in from a remote location and control any device.

Why IrDA? IrDA is intended for point-to-point links between two

devices for simple data transfers and file synchronization.

Technical Specifications

Transmission Technology Bluetooth & HomeRF: Radio Frequency IrDA: Infrared Light Beams

Spectrum Bluetooth & HomeRF: 2.45 GHz IrDA: Optical

Technical Specification (cont.)

Connection Type Bluetooth & HomeRF: spread spectrum IrDA: Infrared, narrow beam

Data Rate Bluetooth: 1 MB HomeRF: 2 MB IrDA: 4MB

Technical Specification (cont.) Range

Bluetooth: 3 metersHomeRF: 50 metersIrDA: 1 meter

Maximum # of devicesBluetooth: Up to 8 devices per piconetHomeRF: Up to 127 devices per networkIrDA: 2 devices

Optimal UseBluetooth:HomeRF: Home NetworkingIrDA: Short Range: one-to-one data exchange

Communication Protocols

Applications

RFCOMM / SDP

L2CAP

Host Controller Interface (HCI)

Link Manager (LM)

Baseband

Radio

Bluetooth Defines the requirements for the Bluetooth transceiver device.

Manages physical channels and links (asynchronous and synchronous), handles packets, paging and inquiry to access Bluetooth devices in the area.

Carries out link setup, authentication, link configuration, etc.

Provides a command interface to the baseband controller and link manager, and access to hardware status and control registers.

Provides connection-oriented and connectionless data services to upper layer protocols with protocol multiplexing capability, segmentation, and reassembly operation and group abstractions.

RFCOMM: Provides emulation of serial ports over the L2CAP.

SDP: Provides a means for applications to discover which services are available and to determine the characteristics of those available services

Provides what application are able to run.

Communication Protocols (cont.)

Existing Upper Layers

TCP UDPDEC

TIP

HomeRF MAC Layer

HomeRF PHY Layer

HomeRF

• Physical layer has been modified significantly to reduce cost, while still maintaining more than adequate performance for home usage scenarios .

•Transmit power up to +24dBm

• Receiver Sensitivity in 2FSK

• Optional low power transmit mode: 0 to 4 dBm for portable devices.

• MAC layer is optimized for the home environment and is designed to carry both voice and data traffic.

•Good support for voice and data by using both TDMA and CSMA/CA access mechanisms.

•Support for 4 high quality voice connections.

•High data throughput 1.6Mbps.

•Data security.

•Power management for Isochronous and Asynchronous nodes.

•24 bit Network ID.

HomeRF uses, references and maps existing network layers.

Communication Protocol (cont).

Infrared Link Management

Protocol (IrLMP)

Infrared Link Access Protocol

(IrLAP)

Physical Signaling Layer

• Provides a device-to-device connection• Device discover procedures•Handles hidden nodes

• Provides multiplexing of the IrLAP layer.• Multiple channels above an IrLAP connection•Provides protocol and service discovery by 121.

• Provides continuous operation from contact.• wireless point-to-point link between 2 independent nodes•Data packets are protected using a CRC.• Data transmission from 9600 b/s

Network Topology

Bluetooth Piconet and Scatternet Piconet connects 7 devices with one

host talking to 7 clients. Clients have to talk to each other

through the host. Scatternet allows groups of piconets

to communicate with each other. Scatternet also has a host

controlling groups of piconets.

Spectrum Collisions

HomeRF, Bluetooth, IEEE 802.11b use the same ISM 2.45 GHz frequency band.

If all 3 used in same vicinity, the technologies will disrupt and/or cancel each other.

With FHSS and different hop rates (Bluetooth- 1600 hops/sec, HomeRF?) it minimizes the changes that they will interfere with each other.

HomeRF Interference Immunity Frequency Hopping Spread Spectrum Corruption happen only in small

packets High power transmission Able to avoid some of the interfering

frequency Hopset adaptation makes sure that

retry will be free of interference Less consecutive “bad hops”

HomeRF Security 128-bit key encryption, 32-bit

Initialization Vector(repeats every half a year)

Network ID needed to synchronize frequency hopping

Denial service attack unlikely Disruptor must determine the frequency of HomeRF

access point Access points hop on independent sequences and

time bases HomeRF MAC ignores commands from foreign

network IDs.

Advantage and Disadvantage of the three technologies: Bluetooth

Advantage of Bluetooth

Ad hoc connection Better range than IR Low power

consumption Connect through walls Omnidirectional Implemented by a large

number of companies Voice and data

transmission

Disadvantage of Bluetooth

Low bandwidth Interference Collides with HomeRF No Window XP support New technology,

buggy, not much tools Current cost is high,

$20 Radiation

Advantage and Disadvantage of the three technologies: HomeRF

Advantage of HomeRF

Security Digital voice

transmission Peer to peer and

host/client connection simultaneously

Interference immunity Dedicated

Internet/multimedia support

Disadvantage of HomeRF

Collides with Bluetooth and IEEE 802.11b

Competitor’s price coming down

Multimedia and telephony application not on market

Radiation

Advantage and Disadvantage of the three technologies: IrDA

Advantage of IrDA

Cheap $2 Compact, lightweight,

low-power Intuitive and easy to

use Noninterfering Best ad hoc, point and

shoot Inherently more secure

than RF

Disadvantage of IrDA

Line of sight only Device cannot move

around while transmitting

Point to point connection only

Short distance

Application usage: Bluetooth Cell phone and PDA: Bluetooth Needs filled by Bluetooth

Connect to multiple devices at the same time Unconsciousness synchronization Small, low energy consumption

Current implementation Make Stylus into cell phone and keep PDA as

base Able to walk around the room while on the

phone(stylus)

Application usage: Bluetooth Cell phone and PDA: Bluetooth Cont. Application can be platform and

hardware independent Bluetooth HCI (Host Control Interface) layer

allows abstraction from hardware ie PCI card or USB adaptor

Java/JINI allows abstraction from OS Bluetooth perfect for use in multiple

devices connection on low bandwidth

Application usage: IrDA E-Business cards: IrDA Needs filled by IrDA

More secure than RF Cheap Easy to use Interference free

Current implementation Pint point who you want to share the business

card with Able to exchange information fast and very ad

hoc, point and click

Application usage: IrDA IrDA perfect for use in close proximity

simple connection. Calender, Address Book, Messages

synchronizations

Application usage: HomeRF Video conference: HomeRF Needs filled by HomeRF

Support multiple digital voice lines Transport voice and data simultaneously Secure, encrypted messages Higher interference resistance than Bluetooth Multimedia and Internet support

Current implementation Perform video conference across the Internet with

dedicated support for both voice and data Encrypt meeting with HomeRF security

Application usage: HomeRF HomeRF perfect for use with

multimedia devices.

Summary Bluetooth

RF Portable one-to-many network Cell phone and PDA

HomeRF RF Home and multimedia devices Video conference

IrDA Infrared Portable one-to-one network Calendar, address book, E business cards