Department of Communication Systems Engineering
Ben Gurion University of the Negev
Be’er-Sheva, Israel
Multi-User Client Server
Application over Bluetooth
Piconet
MCSBT
Students :Himan Asaf &Roei Attias
Supervisor: Dr. Chen Avin
Motivation
• In the last few years the number of Bluetooth
devices has grown up, almost in every portable
device we can see a Bluetooth devices.
• Still One of the main problems of this network
is the opportunity to create a multi user
network.
• The multi user network can skip a lot of
Physical imitations, which can open new
commercials opportunity for it.
Bluetooth, Why ?
•
•
•
•
Free!
Portable and Common (cell phone …).
Commercial Potential.
Physical Properties:
– Low Power consumption (0 – 20 dbm)
– Minimum interferences (FH-SS – 79 Channels).
– High rate data transfer (400-700 Kbit/s).
Problem Definition
• Develop a Client-Server application that
extend Bluetooth protocol to support a large
number of clients at a large range (by multi
hop rooting) as well as client mobility.
• Today status – only Piconet.
• Future Develop – Scaternet.
Project’s Goal
Develop an ad-hoc Client-Server application
base on Bluetooth protocol which will support
Multi hop communication.
•
•
•
•
Large clients number
Large physical range.
Client mobility.
Low energy consumption.
Solution Outline
Step 1: Study the Bluetooth protocol.
• Understanding the Bluetooth Physical limits.
• Application Layer.
Step 2: Develop program algorithm.
• Defining network structure.
• Defining protocol message structure.
• Analyze all the “edge” cases.
Step 3: Implement algorithm.
• Implement multi user connection.
• Develop publisher server.
• Support mobility.
Step 4: Experiment at network.
Design Outlines
• 3 main network components :
• D.S - Data Server – The Data .
• P.S - Publisher server – The “Trigger”.
• M.S – Client – Edge Unit.
Network Structure - Publisher
Publisher Server- trigger MS according to it’s
physical distance.
• “wake up” according to the network area.
• Publish Data server address.
• MS Power save – MS “sleep” until receive a
publisher message.
Network Structure – D.S
Data Server (D.S)
•
•
•
•
Simple file server.
Unique MAC address.
Transparency replay.
Unreliable data transport.
• Current implementation– FTP server.
Network Structure – M.S
Client – MS.
•
•
•
•
Most of the logic.
Mobility support – “still alive message”
Inactive – power save.
Routing –
• Routing table – shortest path.
• Hold several path to D.S.
• “Next hop” routing.
• Current implementation– FTP client.
Network Structure – M.S
Client – (continue).
• Two operational mode, live together :
– Message mode.
• Reliable data transport
– Time-out Mechanism.
– ARQ.
– Stop & wait.
– Relay mode
• Relay message to the next hop .
• Unreliable data transport.
Messages Structure
Application
Transport
Network
Data Link
Physical
GUI
•ARQ
• Timeout
•S&W
•Routing table.
•Shortest path.
Bluetooth MAC
Bluetooth physical
layer FH SS
Network Structure(3)
Message Structure :
–
–
–
–
–
–
–
Dest
address
Dest address - destination address.
Source address - source address.
Previous address - previous destination source.
Type – Message Type.
Length- payload length.
Payload - data Payload.
Signature- security signature.
Source
address
Previous
address
Type
Length
Payload
Signature
Network Scheme
Try send
Send
data
Search
again for
message
to
through
C2D.S
hop that
through C3
connected
to D.S .
Connect to
D.S through
C2
Send the data
to D.S.
Connect to
D.S directly
C1/C2
D.S
D.S
C3
C4
Connect to
D.S directly
Send
respond
P.S- Publisher server D.S- Data server
Dest
Dest
Connect to
Wake
and
D.S up
through
search close
C3 hop
to D.S or the D.S
Source
Source
Previous
Previous
C4D.S
P.S
C4
C4
C2D.S
P.S
C4
C- Client
Type
Type
Data
Search
P.msg
Data
Length
Length
1515
--5
Payload
Payload
Payload
Payload
Bus
10:30
Bus
--Bus
toto
to
Tel
Tel
Tel
Aviv
Aviv
Aviv
The End
-Q.A ?