Internet Real-Time LaboratoryArezu Moghadam and Suman Srinivasan

Columbia University in the city of New York

7DS System Design•7DS system is an architecture consisting of a set of

protocols that enables resource sharing among peers that are not necessarily connected to the Internet. This system also enables mobile nodes to gather and relay messages all around the network.

•7DS Components • Proxy Server• Cache manager & Search engine• Multicast Query Server• SMTP Server & MTA

Motivation

7DS is a peer-to-peer data sharing network that exploits node mobility for data dissemination. Any two nodes communicate when they are in proximity. Under this transmission constraint, any pair of nodes is intermittently connected as mobility shuffle node locations.

7DS System7DS System Architecture

7DS Server Specification

Proxy Server Based on the incoming query retrieves the most relevant data object to the user’s request from Internet or local cache.In case of transferring data from Internet a copy of all data objects in the requested web page is stored in the local cache and a related value/key pair is created in the hash-table to ease future access.

7DS Search Engine

When there is neither Internet Connection nor any relevant document to user’s request available in the system, 7DS front page is returned by the 7DS server. User then submits her query into this CGI search page.

Query Multicasts System

7DS System has a feature by which a query can be multicast to 7DS peers. Results to the query are cached in a local database as well. The proxy server uses the query multicast system to fetch the results for the query, and also displays the results of earlier queries.

7DS Data Gathering and Delivery

7DS is capable of gathering and relaying data objects and emergency messages through recently discovered mobile nodes. The core protocol for this part of the system is SMTP to propagate data among MTAs and to manage mailboxes in each mobile node.

7DS Overview

7DS is a disconnected wireless system with no global network connection. 7DS is an unattended network with dynamically changing topology with the goal of maximizing information dissemination and resource sharing among devices in the network.

7DS Applications in the Real World• Mobile Sensing Application:

• Data Sharing in Ad-Hoc Networks• Automated 3-D Site Modeling• Intelligent Mapping of Network Topology

• Distributed Mobile and Wearable Augmented Reality Systems

For More detailed information about this project please contact arezu@cs.columbia.edu.

1. Proxy Server listens to incoming HTTP Requests

2. Query Multicast is sent through a Query Listener & Scheduler

3. SMTP Server listens to the incoming messages and dumps them up to the MTA

IRT – Internet Real-Time Lab

Affiliated with the Computer Science Department at Columbia University conducts research in the areas of Internet and multimedia services

Internet telephony, wireless and mobile networks, streaming, quality of service, resource reservation, dynamic pricing for the Internet, network measurement and reliability, service location, network security, media on demand, content distribution networks, multicast networks and ubiquitous and context-aware computing and communication.

7DS Project Objectives

In this project, we address both theoretical problems in data dissemination and practical implementation on Linux platform.

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