Overcoming the Challenges of Wireless in the Classroom . Patrick Bristow Software Engineer, ConferenceXP External Research & Programs, Microsoft Research Thursday, July 21 th , 2005 Tablet PC Workshop. Outline. What is multicast? Why use multicast over wireless?
Software Engineer, ConferenceXP
External Research & Programs, Microsoft Research
Thursday, July 21th, 2005
Tablet PC Workshop
What Isn’t Multicast?
The Source can’t afford the bandwidth!
The same traffic is going over one link multiple times.
for the animations!
Was born with WWW in early 90’s, butdeployment is far behind expectation!
Wireless is already multicast
Multicast and Unicast Throughput over 802.11b
Data source: Performance of Reliable Transport Protocol over IEEE 802.11 Wireless LAN:
Analysis and Enhancement; Haitao Wu, et al; IEEE InfoCom 2002
Result?It usually takes an act of God to get 20 laptops in the same room to have “usable” wireless.