13-05-2014, 12:32 PM
Bluetooth and Mobile IP
Bluetooth Application Areas
Data and voice access points
Real-time voice and data transmissions
Cable replacement
Eliminates need for numerous cable attachments for connection
Low cost < $5
Ad hoc networking
Device with Bluetooth radio can establish connection with another when in range
Bluetooth
Consortium: Ericsson, Intel, IBM, Nokia, Toshiba…
Scenarios:
connection of peripheral devices
loudspeaker, joystick, headset
support of ad-hoc networking
small devices, low-cost
bridging of networks
e.g., GSM via mobile phone - Bluetooth - laptop
Simple, cheap, replacement of IrDA, low range, lower data rates, low-power
Worldwide operation: 2.4 GHz
Resistance to jamming and selective frequency fading:
FHSS over 79 channels (of 1MHz each), 1600hops/s
Coexistence of multiple piconets: like CDMA
Links: synchronous connections and asynchronous connectionless
Interoperability: protocol stack supporting TCP/IP, OBEX, SDP
Range: 10 meters, can be extended to 100 meters
Documentation: over 1000 pages specification: www.bluetooth.com
Protocol Architecture
BT Radio (2.4 GHZ Freq. Band):
Modulation: Gaussian Frequency Shift Keying
Baseband: FH-SS (79 carriers), CDMA (hopping sequence from the node MAC address)
Audio: interfaces directly with the baseband. Each voice connection is over a 64Kbps SCO link. The voice coding scheme is the Continuous Variable Slope Delta (CVSD)
Link Manager Protocol (LMP): link setup and control, authentication and encryption
Host Controller Interface: provides a uniform method of access to the baseband, control registers, etc through USB, PCI, or UART
Logical Link Control and Adaptation Layer (L2CAP): higher protocols multiplexing, packet segmentation/reassembly, QoS
Service Discover Protocol (SDP): protocol of locating services provided by a Bluetooth device
Telephony Control Specification (TCS): defines the call control signaling for the establishment of speech and data calls between Bluetooth devices
RFCOMM: provides emulation of serial links (RS232). Upto 60 connections
Piconets and Scatternets
Piconet
Basic unit of Bluetooth networking
Master and one to seven slave devices
Master determines channel and phase
Scatternet
Device in one piconet may exist as master or slave in another piconet
Allows many devices to share same area
Makes efficient use of bandwidth
Frequency Hopping
Total bandwidth divided into 1MHz physical channels
FH occurs by jumping from one channel to another in pseudorandom sequence
Hopping sequence shared with all devices on piconet
Piconet access:
Bluetooth devices use time division duplex (TDD)
Access technique is TDMA
FH-TDD-TDMA
Bluetooth Packet Fields
Access code – used for timing synchronization, offset compensation, paging, and inquiry
Header – used to identify packet type and carry protocol control information
Payload – contains user voice or data and payload header, if present
Network integration
Agent Advertisement
HA and FA periodically send advertisement messages into their physical subnets
MN listens to these messages and detects, if it is in the home or a foreign network (standard case for home network)
MN reads a COA from the FA advertisement messages
Registration (always limited lifetime!)
MN signals COA to the HA via the FA, HA acknowledges via FA to MN
these actions have to be secured by authentication
Advertisement
HA advertises the IP address of the MN (as for fixed systems), i.e. standard routing information
routers adjust their entries, these are stable for a longer time (HA responsible for a MN over a longer period of time)
packets to the MN are sent to the HA,
independent of changes in COA/FA
Bluetooth Application Areas
Data and voice access points
Real-time voice and data transmissions
Cable replacement
Eliminates need for numerous cable attachments for connection
Low cost < $5
Ad hoc networking
Device with Bluetooth radio can establish connection with another when in range
Bluetooth
Consortium: Ericsson, Intel, IBM, Nokia, Toshiba…
Scenarios:
connection of peripheral devices
loudspeaker, joystick, headset
support of ad-hoc networking
small devices, low-cost
bridging of networks
e.g., GSM via mobile phone - Bluetooth - laptop
Simple, cheap, replacement of IrDA, low range, lower data rates, low-power
Worldwide operation: 2.4 GHz
Resistance to jamming and selective frequency fading:
FHSS over 79 channels (of 1MHz each), 1600hops/s
Coexistence of multiple piconets: like CDMA
Links: synchronous connections and asynchronous connectionless
Interoperability: protocol stack supporting TCP/IP, OBEX, SDP
Range: 10 meters, can be extended to 100 meters
Documentation: over 1000 pages specification: www.bluetooth.com
Protocol Architecture
BT Radio (2.4 GHZ Freq. Band):
Modulation: Gaussian Frequency Shift Keying
Baseband: FH-SS (79 carriers), CDMA (hopping sequence from the node MAC address)
Audio: interfaces directly with the baseband. Each voice connection is over a 64Kbps SCO link. The voice coding scheme is the Continuous Variable Slope Delta (CVSD)
Link Manager Protocol (LMP): link setup and control, authentication and encryption
Host Controller Interface: provides a uniform method of access to the baseband, control registers, etc through USB, PCI, or UART
Logical Link Control and Adaptation Layer (L2CAP): higher protocols multiplexing, packet segmentation/reassembly, QoS
Service Discover Protocol (SDP): protocol of locating services provided by a Bluetooth device
Telephony Control Specification (TCS): defines the call control signaling for the establishment of speech and data calls between Bluetooth devices
RFCOMM: provides emulation of serial links (RS232). Upto 60 connections
Piconets and Scatternets
Piconet
Basic unit of Bluetooth networking
Master and one to seven slave devices
Master determines channel and phase
Scatternet
Device in one piconet may exist as master or slave in another piconet
Allows many devices to share same area
Makes efficient use of bandwidth
Frequency Hopping
Total bandwidth divided into 1MHz physical channels
FH occurs by jumping from one channel to another in pseudorandom sequence
Hopping sequence shared with all devices on piconet
Piconet access:
Bluetooth devices use time division duplex (TDD)
Access technique is TDMA
FH-TDD-TDMA
Bluetooth Packet Fields
Access code – used for timing synchronization, offset compensation, paging, and inquiry
Header – used to identify packet type and carry protocol control information
Payload – contains user voice or data and payload header, if present
Network integration
Agent Advertisement
HA and FA periodically send advertisement messages into their physical subnets
MN listens to these messages and detects, if it is in the home or a foreign network (standard case for home network)
MN reads a COA from the FA advertisement messages
Registration (always limited lifetime!)
MN signals COA to the HA via the FA, HA acknowledges via FA to MN
these actions have to be secured by authentication
Advertisement
HA advertises the IP address of the MN (as for fixed systems), i.e. standard routing information
routers adjust their entries, these are stable for a longer time (HA responsible for a MN over a longer period of time)
packets to the MN are sent to the HA,
independent of changes in COA/FA