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Presentation of Bluetooth Activities of Aalborg University at BLIP Systems. BLIP Meeting - Agenda. Agenda: Preliminary Results of TCP Performance over Bluetooth (Dennis Dungs, ca. 30 min) Location Information in Bluetooth (Joao Figueiras, ca. 30 min)

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Presentation of bluetooth activities of aalborg university at blip systems

Presentation of Bluetooth Activities of Aalborg University at BLIP Systems


Blip meeting agenda

BLIP Meeting - Agenda

  • Agenda:

    • Preliminary Results of TCP Performance over Bluetooth (Dennis Dungs, ca. 30 min)

    • Location Information in Bluetooth (Joao Figueiras, ca. 30 min)

    • Scatternet Formation (Istvan Kovacs, ca. 30 min)

    • Set-up of experimental Bluetooth network at Aalborg University(who??, 10 min)

    • Bluetooth simulation tools (who??, 10 min)


Implementation and evaluation of a performance enhancing proxy for wireless tcp

Implementation and Evaluation of a Performance Enhancing Proxy for Wireless TCP

Master Thesis Project (Sep 03 – April 04)

Dennis Dungs

Technical University Munich, Germany

Aalborg University, Denmark

March 2004

Supervised by

Hans-Peter Schwefel

Aalborg University, Denmark


Agenda

Agenda

  • Goal and steps of this project

  • Considered Scenarios in the project

  • Short Reminder: TCP

  • Evaluation of Bluetooth Performance

    • UDP in Single MN AP Scenario

    • TCP in Single MN AP Scenario

  • Conclusions


Goal of this project

Goal of this project

  • Goal:

    • Identify TCP performance lacks in wireless scenarios

    • Evaluate performance capabilites of a TCP Proxy

  • Steps

    • Getting familiar with concepts of TCP

    • Research about common TCP implementations

    • Describing wireless scenarios

    • Analyzing TCP performance and Identifying TCP performance lacks in wireless scenarios

    • Designing and Implementing a TCP Proxy

    • Evaluation of Scenarios using the TCP Proxy


Considered scenarios

Considered Scenarios

Wireless

supporting Network

Proxy

Wired Network

Mobile

Host

Server

  • Definition:

    „A Scenario consists of a description of the network infrastructure, mobility model and traffic model.“

  • Network Infrastructure:

    • Access Technology

    • Proxy Location

    • Sender / Receiver Location

    • Network configuration

  • Mobility Model

    • Fixed position

    • Handover to same/different subnet

    • Handover to new access technology

  • Traffic Model

    • Size of transmitted data

    • Used bandwith

    • Single-/Multi-User

    • Cross-traffic

    • Constant / Burst Traffic


Short reminder tcp

Short Reminder - TCP

  • Goals of TCP:

    • Connection oriented, full duplex protocol

    • Multiplexing of IP-datagram service (Ports)

    • In-order data transfer (Sequence Numbers)

    • Reliable data transfer (Acknowledgements)

    • Prevent Receiver from flooding (Receiver Advertised Window)

    • Prevent intermediate systems from flooding (Congestion Control Algorithm)

  • Congestion Control

    • Congestion Window: Number of bytes, that can be send in one RTT without congestion

    • Dynamically adjusted until congestion indicated via DUPACKs or timeouts

    • Exponential increase per RTT to reach maximum throughput (slow-start)

    • Continuous probing of maximum available bandwith via linear increase/ multiplicative decrease per RTT


Evaluation

Evaluation


Evaluation measurement procedure

Evaluation – Measurement Procedure

  • IPerf

    • Setup a UDP/TCP connection from sender to receiver

    • Send data from sender to receiver at maximum bandwidth (TCP) or given bandwidth (UDP)

  • Ethereal

    • Trace Ethernet packets at sender and receiver in real-time into a file

    • Traces arrival times of packets t(n) and contents of Ethernet packets

  • TCPTrace

    • Generate TCP Statistics offline

  • Matlab

    • Generating UDP Statistics offline

    • Calculating statistical parameters

  • GNUPlot

    • Visualizing TCP Statistics (RTT Graphs, Throughput Graphs)


Evaluation metrics

Evaluation - Metrics

  • Instantaneous Throughput

  • Instantaneous Averaged Throughput

  • Transmission Throughput

  • Round-Trip-Times (RTT)


Single connection over bluetooth scenario

Single Connection over Bluetooth - Scenario

Delft

China

Aalborg

Shanghai

Toronto

Network Setup:

  • Scenario Parameters:

    • MN: 2.6 GHz-P4 512MB RAM, WinXP, Belkin Class2 BT USB Adapter

    • AP: BlipNet BlipNode L1

    • Supposed Master: AP

    • Supposed Slave: Mobile Node

    • Application Profile: PAN

    • Distance AP->MN: 1m

    • Server: PPro 166Mhz, 32MB RAM, running Redhat 7.3

    • Sending duration: 30sec

    • UDP payloadsize: 1470 bytes

    • UDP Bandwith: 700kBit/s (Application Layer Bandwith)

    • TCP receiver buffer: 8 kBytes

8 MBit/s

8 MBit/s

Tokyo

100 MBit/s

100 MBit/s

100 MBit/s

100 MBit/s

Server

10.10.3.254

10.10.1.X

Downstream

Mobile Node

Legend:

Router

Switch

BT AP

Fixed Host

Mobile Host


Single udp connection over bluetooth

Single UDP Connection over Bluetooth


Single udp connection over bluetooth1

Single UDP Connection over Bluetooth


Single tcp connection over bluetooth

Single TCP Connection over Bluetooth


Single tcp connection over bluetooth1

Single TCP Connection over Bluetooth


Single tcp connection over bluetooth2

Single TCP Connection over Bluetooth

  • Possible Reasons for throughput jumps

    • Traffic in low-bandwidth direction (Routers)

      • Packet Scheduler has to send more data

      • Adjusting to „more symmetric“ bandwidth

      • Flow Control on Baseband

    • Interference

      • Channel quality driven data rate change (CQDDR)


Additional results

Additional Results

  • Upstream (Slave->Master) gains always higher throughput than downstream

  • Adhoc – Scenario:

    • Same throughput jumps (UDP & TCP) as in AP-scenario, but less likely

    • Higher average throughput

  • No significant differences between WinXP (WidComm-Stack) and Linux (BlueZ-Stack)


Conclusions questions

Conclusions - Questions

  • Conclusion:

    • Many factors could cause the throughput-dropdown

    • Difficult to analyze TCP performance lacks, if underlying behaviour unclear

    • To get deeper understandings, packet trace tool for Baseband is needed


References

References

  • Project WebSite:

    http://kom.aau.dk/~dennis/

  • IPLab WebSite:

    http://kom.aau.dk/iplab/

  • RFCs : RFC791 (IP), RFC793 (TCP), a.o.

    http://www.ietf.org/

  • Bluetooth Specification

    http://www.bluetooth.org/

  • eMail:

    [email protected]


Presentation of bluetooth activities of aalborg university at blip systems

Thanks for listening!

Any Questions?

Yes, i have some...


Questions

Questions

  • How to figure out, which Bluetooth device is master, which is slave (role switching)?

  • How to figure out, which packet types are used (DM, DF, AUX) ?

  • How to figure out, if master/slave uses „Channel quality driven data rate change” and when it affects the channel

  • How to figure out, how “Flow Control” on baseband level is influencing the throughput?

    => Is it possible to trace packets at Baseband level?


Backup

Backup


Adhoc udp connection over bluetooth

Adhoc UDP Connection over Bluetooth

  • Scenario Parameters

    • MN 1: 2.6 GHz-P4 512MB RAM, WinXP, Belkin Class2 BT USB Adapter

    • MN 2: 266MHz-P 64MB RAM, WinXP, Belkin Class2 BT USB Adapter

    • Supposed Master: MN 1

    • Supposed Slave: MN 2

    • Application Profile: PAN

    • Distance MN1->MN2: 1m

    • Sending duration: 10sec

    • UDP payload-size: 1470 bytes

    • UDP Bandwith: 700kBit/s (Application Layer Bandwith)

Mobile Node 2

(supposed Slave)

Mobile Node 1

(supposed Master)

UDP Downstream

UDP Upstream


Adhoc udp connection over bluetooth downstream

Adhoc UDP Connection over Bluetooth - Downstream


Adhoc udp connection over bluetooth upstream

Adhoc UDP Connection over Bluetooth - Upstream


Adhoc udp connection over bluetooth comparison

Adhoc UDP Connection over Bluetooth - Comparison


Adhoc tcp connection over bluetooth

Adhoc TCP Connection over Bluetooth

  • Scenario Parameters

    • MN 1: 2.6 GHz-P4 512MB RAM, WinXP, Belkin Class2 BT USB Adapter

    • MN 2: 266MHz-P 64MB RAM, WinXP, Belkin Class2 BT USB Adapter

    • Supposed Master: MN 1

    • Supposed Slave: MN 2

    • Application Profile: PAN

    • Distance MN1->MN2: 1m

    • Sending duration: 10sec

    • Standard WinXP TCP Implementation

    • TCP Window Size: 8kByte

Mobile Node 2

(supposed Slave)

Mobile Node 1

(supposed Master)

TCP Downstream

TCP Upstream


Adhoc tcp connection over bluetooth comparison us ds

Adhoc TCP Connection over Bluetooth – Comparison US/DS


Adhoc tcp connection over bluetooth1

Adhoc TCP Connection over Bluetooth


Current iplab network architecture

Current IPLab network architecture

IP LAB: Current Architecture

Aalborg

Shanghai

Internet

Toronto

10.10.2.254

Istanbul

10.10.3.254

10.10.4.2

10.10.254.254

10.10.3.1

San Francisco

130.225.51.6

Tokyo

Frankfurt

Delft

GPRS Network

10.10.2.1

10.10.1.1

Toronto

Shanghai

10.10.1.254

10.10.1.2

10.10.2.2

Sydney

Dhaka


Single tcp connection over bluetooth scenario

Single TCP Connection over Bluetooth - Scenario

Delft

China

Aalborg

Shanghai

Toronto

Network Setup:

  • Scenario Parameters:

    • MN: 2.6 GHz-P4 512MB RAM, SuSE Linux 9.0 (Kernel 2.4.21-166), BlueZ Stack (Lib 2.5, SDP 1.5, PAN 1.1)

    • AP: BlipNet BlipNode L1

    • Master: AP

    • Slave: Mobile Node

    • Application Profile: PAN

    • Distance AP->MN: 1m

    • Server: PPro 166Mhz, 32MB RAM, running Redhat 7.3

    • Sending duration: 30sec

    • Standard TCP Implementations

    • TCP Window Size: 8kByte

8 MBit/s

8 MBit/s

Tokyo

100 MBit/s

100 MBit/s

100 MBit/s

100 MBit/s

Server

10.10.3.254

10.10.1.X

Mobile Node

Legend:

Router

Switch

BT AP

Fixed Host

Mobile Host


Single tcp connection over bluetooth linux

Single TCP Connection over Bluetooth (Linux)


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