Download presentation
Presentation is loading. Please wait.
Published byFrederick Nichols Modified over 9 years ago
1
Interference and Service Discovery in Multi-Hop Ad Hoc Networks Alex Varshavsky University of Toronto
2
2 Multi-Hop Mobile Ad Hoc Networks (MANETs) Wireless medium Mobile nodes No fixed infrastructure Each node acts as router Applications Relief operations Battlefield A F
3
3
4
4 Multi-hop Networks No Spatial Reuse A F B C DE
5
5 Multi-hop Networks Spatial Reuse A F B C DE
6
6 Throughput Measurement Chains of different length Traffic pattern Constant Bit Rate (CBR) … …
7
7 CBR Throughput 55% Drop
8
8 Wireless Transmission ABC DATA Collision Hidden terminal CSMA/CD doesn’t work Use CSMA/CA
9
9 Interference Range ABC DATA D Interference Range = 550m Transmission Range = 250m
10
10 The Hidden Terminal Problem ABC DATA DEF Collision
11
11 CBR Throughput Self-interference Throughput depends route length sending rate
12
12
13
13 MANET in Action Gee…I wear a Video Camera Cool ! I act as Video Redirector
14
14 MANET in Action I still wear a Video Camera Now I act as Video Redirector
15
15 Service Location Protocol (SLP) Discover services Two modes of operation Centralized Distributed
16
16 Service Location Protocol (SLP) Centralized Mode User Agent Service Agent Directory Agent CameraVideo Redirector Find “video redirector” ! Register “video redirector” Find “video redirector” ! Register “video redirector” C D S1 S2
17
17 Service Location Protocol (SLP) Centralized Mode User Agent Service Agent Directory Agent CameraVideo Redirector Find “video redirector” ! Register “video redirector” Find “video redirector” ! Register “video redirector” C D S2 S1
18
18 Service Location Protocol (SLP) Centralized Mode User Agent Service Agent Directory Agent CameraVideo Redirector Find “video redirector” ! Register “video redirector” Find “video redirector” ! Register “video redirector” C D I found the video redirector S2 S1
19
19 Service Location Protocol (SLP) Distributed Mode User Agent Service Agent CameraVideo Redirector Find “video redirector” ! Register “video redirector” Find “video redirector” ! C S1 S2
20
20 Service Location Protocol (SLP) Distributed Mode User Agent Service Agent CameraVideo Redirector Find “video redirector” ! Register “video redirector” Find “video redirector” ! C I found the video redirector S1 S2
21
21 Service Discovery in MANETs Centralized Hard to maintain Easy to lose Distributed Large overhead
22
22
23
23
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.