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 ProtocolsApplications
RFCOMM / SDP
L2CAPHost 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