Download
routing voip over multichannel multi radio wireless networks n.
Skip this Video
Loading SlideShow in 5 Seconds..
Routing VoIP over Multichannel, Multi-Radio Wireless Networks PowerPoint Presentation
Download Presentation
Routing VoIP over Multichannel, Multi-Radio Wireless Networks

Routing VoIP over Multichannel, Multi-Radio Wireless Networks

136 Vues Download Presentation
Télécharger la présentation

Routing VoIP over Multichannel, Multi-Radio Wireless Networks

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Illinois Center for Wireless Systems Routing VoIP over Multichannel, Multi-Radio Wireless Networks Vijay Raman and Nitin H. Vaidya University of Illinois at Urbana-Champaign ICWS Summer School, 2009

  2. Net-X Testbed • Multi-channel, multi-interface wireless testbed • 20+ Soekris net4521 boards • Linux 2.4 kernel • Two 802.11a radiosper node (1 mini-PCI and 1 PCMCIA) • Runs a suite of multi-channel protocols

  3. One interface fixed on a channel & the other capable of switching channels Channel allocation algorithm assigns only fixed interface channels Switchable interface switches to neighbor’s fixed channel for sending data Fixed interface used for receiving data Multichannel Protocol (HMCP)[Kyasanur and Vaidya ’05]

  4. Multichannel Routing • Modified AODV routing protocol • Next hop information includes channel and interface to use • Channel diverse paths preferred

  5. Problem Definition • HMCP optimized for throughput • Provides network connectivity • Multichannel protocols enhances throughput • `Switch to transmit’ incurs delay • Channel switching delay, 5 ms • Service a channel for a minimum duration, 20 ms • Adds up over a multihop route! • Such high delays not suitable for RT applications • Eg. VoIP : < 150 ms delay preferred

  6. Alternative Mechanism • Static Channel Allocation • At least one channel common between two neighbors • No channel switches • Downside • Requires topology knowledge • Idea • Use static channel mechanism for RT applications

  7. SHORT: Static-Hybrid Approach • Source indicates RT flow during route discovery • Destination and intermediate nodes `fix’ switchable radio to previous hop’s fixed channel • No more channel switches during RT flow • Even for broadcast!

  8. DEMO

  9. Performance Results Single Flow Case

  10. Performance Results Multi Flow Case

  11. Performance Results VoIP with TCP

  12. Thank You! http://www.crhc.illinois.edu/wireless/