7DS7DSPeer-to-Peer Information Peer-to-Peer Information

Dissemination and Prefetching Dissemination and Prefetching ArchitectureArchitecture

Stelios Sidiroglou-Douskos CS Seminar –Timo Ojala

June 10, 2004

What is 7ds?What is 7ds? Message-based application-layer service

propagates information objects among mobile nodes that are within high-speed wireless range

Carry data using mobile nodes To and from infrastructure networks

Scales with the user population in a given area

No infrastructure planning or deployment

7DS approach7DS approach

Data sharing among mobile hosts in a  peer to peer fashion.

7DS can coexist with other methods for data access, e.g. via FIS or BS to the Internet.

7DS as extension of infrastructure and ad-hoc networks

7ds applications7ds applications Wireless web caching

Cheaper, faster links Emergency Infrastructure

“I’m alive” messages, rescue info Wireless peer-to-peer sharing

Maps, schedules, email Wireless mobile sensors

Too far to directly communicate Vehicle Transportation

Leverage local data

Basic ideaBasic idea

Device wants to get an object Web page, map, local weather Obtain from peer within range Periodically query for object

Device wants to send an object Email, SMS, I-am-alive Pass to nearby peer

ArchitectureArchitecture

Data access engine 802.11, Bluetooth

Cache manager Content cache, reputation, popularity

Search engine Keyword searching, indexing

Decision maker Periodic, power-save, forwarding

7ds Architecture7ds Architecture

HTTP ArchitectureHTTP Architecture

Communication ProtocolCommunication Protocol

ExampleExample

Object RelayObject Relay

propagate to otherpedestrians

7DSMTA

encrypt message;encrypt headers with 7DS public key

Periodically advertise presence Relay location-based

information (velocity, destination, available buffer size)

Select candidate nodes to relay message

Push object to candidate nodes

Applications for message Applications for message passingpassing

Email objects Relaying SMS messages in

congested/damaged areas Message relaying in sensor

networks Traffic management information

relaying

Pager as feedback channelPager as feedback channel

MTA

PL-900 POCSAG

SNPP(RFC 1861)

FLEX1600-6400 b/s

“message 42 delivered”

removefrom

cache

ConclussionsConclussions

7DS as extension of infrastructure and ad-hoc networks

Combine benefits of low bit-rate, but ubiquitous and high bit-rate, but sparse networks