Routing in BlueTooth Scatternet

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Routing in BlueTooth Scatternet

• Liron Har-Shai 040484792
• Ronen Kofman 037694098
• Supervisor
• Gil Zusman

2
Project Goals

• Get familiar with the NS simulation environment
• Get familiar with BT specification
• Implement a degenerated model to simulate
  Inter-Piconet packet flow
• Implement routing protocol(s) of BT Scatternet on
  the NS
• Measure the BT Scatternet performance

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BlueTooth Overview

• Bluetooth is the codename for a technology
  specification for small form factor, low-cost,
  low-power, short range radio links between mobile
  PCs, mobile phones and other portable devices.
• A global specification for wireless connectivity.
  Bluetooth is a cable replacement technology that
  simplifies the interaction between people as well
  as machines.

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BlueTooth Layers
Adapted
LLC layer
MAC layer
Core
PHY layer
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Piconet Overview

• Piconets are created ad-hoc
• Piconet consists of one master and up to seven
  slaves and works in a Master-Slave concept.
• In forming a piconet (connection), master gives
  the slave its clock (offset) and a device I.D.
• Piconet is defined by itsfrequency hopping
  sequence. All devices hop together. Hopping
  pattern determined by masters I.D. (48-bit)

slave 3
slave 1
master
slave 2
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Piconet continue

• STATES of a BT station
• STANDBY-Waiting to join a piconet
• INQUIRY-Ask about radios to connect
• PAGE-Connect to a specific radio.
• CONNECT-Actively on a piconet (master or slave)
• SNIFF/PARK/HOLD-Low Power connected states
• Common interaction
• The device which initiates the connection becomes
  the master, however the master and slave roles
  can be changed at any time using the master slave
  switch procedure.
• The master is supposed to poll the slave(s) at
  regular intervals to allow them to send data. The
  polling-interval is negotiated between the master
  and the slave.

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Scatternet Structure
bridge
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Problems Solutions

• Open Issues
• The bridge functionality
• How to maintain connection with more than one
  piconet.
• How frequently the bridge should switch between
  piconets.
• Bridges state when switching between piconets.
• The scheduling policy inside the piconet
• Round Robin policy
• Fixed/Adjusted Priority to bridge within the
  piconet
• Other load issues

• Our decisions
• The bridge node will go into HOLD mode for a
  fixed given time when switching between piconets.
• We will start with Round Robin policy.
• Other issues will not be dealt in this stage.

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Enviroment CAD Tools

• Network Simulator (NS)- simulation platform based
  on C and Otcl languages. This platform is
  currently the only available platform for
  BlueTooth simulation.
• Network Animator (NAM)- allows us to view the
  simulation results in a graphical way.
• Perl- we will use the perl language to analyze
  the trace files.

The work with the NS is quite complex, and due to
that it requires previous knowledge in unix. For
those reasons we had to install it ourselves.
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Major Milestones

• Setting up the simulation environment and getting
  started DONE
• Getting familiar with the BlueTooth spec
• we got to a point that enable us to start the
  implementation
• Implementing a degenerated model of Scatternet
• we are currently working on it. We expect to
  finish this stage and start doing simulations by
  the end of this semester.
• In the next semester we plan to
• Implement few routing protocols
• Measure their performance over the Scatternet