System Study of the Wireless Multimedia Ad-hoc Network based on IEEE 802.11g

1
System Study of the Wireless Multimedia Ad-hoc
Network based on IEEE 802.11g

• Authors
• Chung-Wei Lee
• Jonathan C.L. Liu Kun Chen
• Yu-Chee Tseng S.P. Kuo
• Presented by
• Nandita Uppalapati
• Deepthi Thanigundala

2
System Study of the Wireless Multimedia Ad-hoc
Network based on IEEE 802.11g

• 1) Introduction
• 2) Related work
• 3) Experiments
• 3-1) Indoor without obstructions
• 3-2) Outdoor without obstructions
• 3-3) Penetrating wall
• 4) Results and Analysis
• 4-1) Indoor without obstructions
• 4-2) Outdoor without obstructions
• 4-3) Penetrating wall
• 5) Proposed Schemes and Protocols
• 6) Large scale simulations
• 7) Conclusions

3
1. Introduction
4
(No Transcript)
5
Introduction

• High Bandwidth
• 54 Mbps 802.11g is used to replace 11Mbps 802.11b
  networks
• Working in mixed environments
• Obtain baseline performance with different
  conditions like in Indoors walls, ceiling,
  desks, chairs which scatter the signal
• Outdoors natural obstacles and humidity,
  temperature
• moving objects like people, cars
• -gtsignals tend to propagate like water
  ripples

6
Adhoc Network
7
Software Benchmarking

• For multi-media applications
• Environmental effects should be considered
• Wireless environment
• Higher error rates for data transmission gt
  average performance at the users end.
• Software emulates constant streaming of
  multimedia data between two hosts.

8
Observations

• Conventionally, bandwidth of the ad-hoc networks
  is usually large when distance between the
  laptops is less.
• But that is not the case always.
• - Indoor
• Worst performance within 5meters.
• UDP outperformed TCP up to 38.5 in achieved
  bandwidth.

9
Observations-contd

• - Outdoor
• TCP favors short distance (5meters) or long
  distance (25meters)
• UDP was best at 10meters
• - Wall penetration
• Routing nodes within 5meters.
• else overall bandwidth reduces
  significantly.

10
Proposed Algorithm

• ?Proposed MaxThroughput algorithm to find paths
  with sufficient bandwidth guarantee
• ?Result
• - better path
• - bandwidth about 30 higher than conventional
  methods
• even though, node number is small and path
  selection is limited

11
System Study of the Wireless Multimedia Ad-hoc
Network based on IEEE 802.11g

• 1) Introduction
• 2) Related work
• 3) Experiments
• 3-1) Indoor without obstructions
• 3-2) Outdoor without obstructions
• 3-3) Penetrating wall
• 4) Results and Analysis
• 4-1) Indoor without obstructions
• 4-2) Outdoor without obstructions
• 4-3) Penetrating wall
• 5) Proposed Schemes and Protocols
• 6) Large scale simulations
• 7) Conclusions

12
Related Work

• Finding optimal solution satisfying multiple QoS
  is NP-complete.
• Distance factor was not considered in any of the
  previous studies.

13
System Study of the Wireless Multimedia Ad-hoc
Network based on IEEE 802.11g

• 1) Introduction
• 2) Related work
• 3) Experiments
• 3-1) Indoor without obstructions
• 3-2) Outdoor without obstructions
• 3-3) Penetrating wall
• 4) Results and Analysis
• 4-1) Indoor without obstructions
• 4-2) Outdoor without obstructions
• 4-3) Penetrating wall
• 5) Proposed Schemes and Protocols
• 6) Large scale simulations
• 7) Conclusions

14
3. Experiments

• Hardware required
• - Laptop computers with Pentium IV processor,
  512 M memory, 40G hard disk
• - Two identical wireless adapters
• - Linksys 802.11g wireless cards use 2.4-GHz
  frequency (bandwidth up to 54Mbps), mode
  set to ad-hoc mode and number of channel is set
  to six
• - Subnet mask 255.255.255.0, gateway function
  disabled
• Software required
• - Windows XP operating system
• - Benchmarking software on top of the
  TCP/UDP/IP protocols
• ?Benchmarking software discards top 2.5 and
  bottom 2.5 of the measured results gt only 95
  interval of the average performance is
  represented

15
Indoor without obstructions

• Location Computer and Information Science
  Engineering basement building in order to
  minimize interference of access point of the
  infrastructure wireless connections
• Experiment at three different distances
• TCP, UDP 5meter
• TCP, UDP between 5 and 10 meters
• TCP, UDP between 10 and 20 meters

16
Outdoor without obstructions

• Location Parking lot at VA hospital
• Less cars parked far away, in order to minimize
  interference of cars
• Experiment done at similar distances as that of
  Indoor
• 5meters, 5 and 10meters, 10 and 20meters

17
Penetrating wall

• Location New Physics building basement in order
  to minimize interference
• Laptop inside the building is fixed and the one
  which is outside the building is moved to
  maintain distance between them
• Experiment at three different distances
• TCP, UDP 5meter
• TCP, UDP between 5 and 10 meters
• TCP, UDP between 10 and 20 meters

18
System Study of the Wireless Multimedia Ad-hoc
Network based on IEEE 802.11g

• 1) Introduction
• 2) Related work
• 3) Experiments
• 3-1) Indoor without obstructions
• 3-2) Outdoor without obstructions
• 3-3) Penetrating wall
• 4) Results and Analysis
• 4-1) Indoor without obstructions
• 4-2) Outdoor without obstructions
• 4-3) Penetrating wall
• 5) Proposed Schemes and Protocols
• 6) Large scale simulations
• 7) Conclusions

19
4. Results and Analysis
Results-Indoor conditions
Indoor TCP Throughput
Increase in the size of messages resulted in
increased throughput
20
Results-Indoor conditions

• Ad-hoc mode performs worst with the distance lt
  5meters
• Increasing distance improves throughput
• Reason?
• - Multi-path propagation of radio frequency

21
Results-Indoor conditions
Unit Size influence , UDP
Increase in unit size gt throughput for UDP
increased UDP protocol stack reduces headers and
overhead gt throughput performance increases
significantly Peak average throughput 18Mbps
38.5 improvement
22
Results-Indoor conditions
Indoor UDP Throughput

• UDP

23
Results-Outdoor without Obstructions
Outdoor TCP Throughput
24
Results-Outdoor without Obstructions

• As the experiment was performed on-campus, some
  factors were eliminated
• Multi-path interference has less effect
• TCP protocol
• best 5 or 25 meters
• worst 20 meters

25
Results-Outdoor without Obstructions
Output UDP Throughput
26
Results-Outdoor without Obstructions

• Performance improved to 19.1 Mbps, message size
  2Mbyte
• Best performance _at_ 10 meters
• If message size gt 256 Kbytes, distance has
  limited impact on achieved bandwidth

27
Results-Penetrating Walls
TCP Penetrating Walls
28
Results-Penetrating Walls
UDP
29
System Study of the Wireless Multimedia Ad-hoc
Network based on IEEE 802.11g

• 1) Introduction
• 2) Related work
• 3) Experiments
• 3-1) Indoor without obstructions
• 3-2) Outdoor without obstructions
• 3-3) Penetrating wall
• 4) Results and Analysis
• 4-1) Indoor without obstructions
• 4-2) Outdoor without obstructions
• 4-3) Penetrating wall
• 5) Proposed Schemes and Protocols
• 6) Large scale simulations
• 7) Conclusions

30
Proposed Schemes and Protocols

• Algorithm RandomTopology(n)
• Algorithm MinHop(u)
• Algorithm MaxThroughput(u)

31

• Notation
• - bw(i,j) link bandwidth as a function of
  physical distance
• - H(v) current hop count from the source node u
  to destination v
• - B(v) current path bandwidth from the source
  node u to destination v
• - N the set contains all nodes in a topology
• - N a subset of N

32
Algorithm RandomTopology(n)
33
Algorithm MinHop(u)
34
(No Transcript)
35
System Study of the Wireless Multimedia Ad-hoc
Network based on IEEE 802.11g

• 1) Introduction
• 2) Related work
• 3) Experiments
• 3-1) Indoor without obstructions
• 3-2) Outdoor without obstructions
• 3-3) Penetrating wall
• 4) Results and Analysis
• 4-1) Indoor without obstructions
• 4-2) Outdoor without obstructions
• 4-3) Penetrating wall
• 5) Proposed Schemes and Protocols
• 6) Large scale simulations
• 7) Conclusions

36
Large Scale Simulations

• Experiments designed to handle 300meters x 300
  meters area
• MinHop routing
• MaxThroughput
• UDP

37
Large Scale Simulations
38
(No Transcript)
39
(No Transcript)
40
System Study of the Wireless Multimedia Ad-hoc
Network based on IEEE 802.11g

• 1) Introduction
• 2) Related work
• 3) Experiments
• 3-1) Indoor without obstructions
• 3-2) Outdoor without obstructions
• 3-3) Penetrating wall
• 4) Results and Analysis
• 4-1) Indoor without obstructions
• 4-2) Outdoor without obstructions
• 4-3) Penetrating wall
• 5) Proposed Schemes and Protocols
• 6) Large scale simulations
• 7) Conclusions

41
Conclusion

• Distinct performance differences between
  indoor/outdoor environment and penetrating walls
• Improved end-to-end bandwidth significantly
• Carefully choose node-to-node routing distances
• Still in process
• To optimize the performance improvement
  placement flexibility
• Challenge
• Support concurrent connections simultaneously
• Achieving global optimization (Bandwidth,
  Fairness and QoS)

42

• Observations
• Outdoor experiments conducted when there
  are less vehicles and neglected many
  environmental obstacles

43

• Questions???