Rover technology

Rover Technology Enabling Scalable Location Aware Computing ( Wireless ):

Rover Technology Enabling Scalable Location Aware Computing ( Wireless ) Myoung – Seo Kim Super Computing Lab. 2003.04.28

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Introduction Rover Services Rover Architecture Rover Clients Rover Controller Rover Database Bottlenecks Conclusions Contents

Introduction(1):

Introduction(1) Shop to Shop Information on newly - released data in his favorite categories are downloaded automatically into his PDA , along with their availability information. We refer to this paradigm as Location aware computing.

Introduction(2):

Traditional notions of Time-aware, User-aware, and Device-aware. + Local-aware (in Rover). location service that can track the location of every user, either by automated location determination technology or by the user manually entering current location. Available via a variety of wireless access technologies. (IEEE 802.11 wireless LANs, Bluetooth, Infrared, cellular services) Devices (laptop, PDA, cellular phone) Introduction(2)

Introduction(3):

Scales to a very large client population. Rover achieves this through fine resolution application specific scheduling of resources at the servers and the network. Introduction(3)

Rover Services(1) :

Rover Services(1) Enables a Basic set of data services in different media formats, including text, graphics, audio, and video. Transactional services coordination of state between the clients and rover servers. ex) e-commerce interactions

Rover Services(2) :

Services that require location manipulation are a particularly important class of data services in Rover. Locations an important attribute of all objects in Rover. – value, error, timestamp Rover Services(2)

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Filter : Applied to maps to select the appropriate subset of objects to display to the users. Zoom : Displayed map identifies it’s granularity. Translate : Translated from the previously displayed map. Map based services

Rover Architecture :

Rover Architecture Rover maintains a user profile for each end-user, that defines specific interests of the user and is used to customize the content served. Rover-clients are the client devices through which users interact with Rover. Rover maintains a device profile for each device.

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Wireless access infrastructure Servers – Rover controller Brain of Rover system – Location server – Media streaming unit – Rover database – Logger Rover physical architecture(1)

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Rover physical architecture(2)

Action model :

Action model Ready-to-run: At least one action of the server operation is eligible to be executed but no action of the server operation is executing. Running: One action of the server operation is executing ( in a multi-processor setup, several actions of the operation can be executing simultaneously ). Blocked: The server operation is waiting for asynchronous I/O response and no actions are eligible to be executed.

Actions vs Threads :

Actions vs Threads

Overheads:

Overheads

Rover logical architecture :

Rover logical architecture

Rover Database :

Rover Database User infobase and Content infobase. Each transaction is identified - Lock-Acquiring - Blocking Avoiding Deadlocks - Two phase Locking Protocol.

Multi Rover System :

Multi Rover System Each separate museum has its independent administrative authority. Therefore, we can have a separate Rover system for each of the different museums that are administered separately by each museum authority.

Initial Implementation(1) :

Initial Implementation(1) Indoor and Outdoor environments. - developed under the Linux operating system. - Compaq iPAQs Pocket PC. A GPS-device to the Compaq iPAQs and obtained device location accuracy of between 3-4 meters of outdoor .

Initial Implementation(2) :

12 base stations that are distributed all over the building and typically the client device can receive signals from five or six of the base stations . University of Maryland. get an accuracy of better than a meter in this environment, using very simple signal strength based estimation techniques. Initial Implementation(2)

Bottlenecks:

Bottlenecks A large number of client requests with tight real time constraints. Wireless access points – Limited bandwidth .

Conclusions :

Conclusions We believe that Rover Technology will greatly enhance the user experience in a large number places, including visits to museums, amusement and theme parks, shopping malls, game fields, offices and business centers. The system has been designed specifically to scale to large user populations. Therefore, we expect the benefits of this system to be higher in such large user population environments.