7DS: Exploring Multimodal Networking

1
7DS Exploring Multimodal Networking

• Henning Schulzrinne
• Dept. of Computer Science
• Columbia University

NSF I/UCRC Planning Meeting, September 18, 2003
2
Wireless Network filling the infrastructure-ad
hoc gap

• Wireless networks
• Ubiquitous, fast, cheap pick any two
• Currently, varies from 0.1c to 4/MB
• Research has primarily explored
• one-hop infrastructure extension (2G, 3G, 802.11)
• multi-hop connected ad-hoc networks
• But
• 2G/3G bandwidth will remain low and precious
• hot spots not ubiquitous
• ad hoc networks dont scale brittle if spanning
  large areas
• Our proposal use mobile nodes to carry data

3
Applications

• Tourism
• get information about sights, travel, public
  transport schedules, ..
• upload picture postcards and video recordings
• Transportation
• users in buses and trains leverage data
  capability
• Emergencies
• propagate Im alive and rescue information
• Mobile sensors
• sensors spread too far to communicate directly
  with each other

4
7DS a framework for intermittently connected
networks

• Two directions for data
• Internet ? mobile nodes
• mobile nodes ? Internet
• Each in multiple hops

delay
bandwidth (peak)
5
Realization
6
Current status prototype

• Initial Java implementation
• search not just by URL, but by content
• ? greater likelihood of finding appropriate
  material (news)
• Working on PDA implementations
• Also, considering Linux embedded systems
• low-power, self-contained

7
Combining cellular and 7DS networks

• Proposed research
• Cellular reselling
• pay once for bandwidth, use many times
• Inverse multiplexing
• for high-priority content
• Content location
• find nearest hotspot
• Cache cleaning
• indicate popular content for proactive querying
• remove stale content in m?I

8
Expected Results Impact

• Leverages low-cost mobile devices
• New services that otherwise are not
  cost-effective
• Low initial capital expenditure
• re-use of infrastructure

9
Resource Requirements Cost

• Three components
• theoretical investigation
• prototype software
• hardware modules
• Applying for NSF special-projects grant