Android Smartphone as a Microphone in SmartRoom System Pavel Y. - - PowerPoint PPT Presentation

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May 01, 2023 445 likes •581 views

Android Smartphone as a Microphone in SmartRoom System Pavel Y. Kovyrshin, Dmitry G. Korzun Petrozavodsk State University Department of Computer Science Grant KA179 Complex development of regional cooperation in the field of open ICT

SLIDE 1

Android Smartphone as a Microphone in SmartRoom System

Pavel Y. Kovyrshin, Dmitry G. Korzun

Petrozavodsk State University Department of Computer Science

Grant KA179 “Complex development of regional cooperation in the field

f open ICT innovations” of Karelia ENPI CBC programme 2007–2013 of the European Union,

the Russian Federation and the Republic of Finland

15th FRUCT Conference April 24, 2014, St.-Petersburg, Russia

Pavel Kovyrshin Microphone Service for SmartRoom FRUCT15 1 / 11

SLIDE 2

SmartRoom System Services

Centralized data storage (SIB: Semantic Information Broker) Many mobile clients

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SLIDE 3

Microphone-service: High Level Architecture

JNI - enables Java to use native implementations SmartSlog - provides API for Smart Space interaction JSpeex - audio processing Java module DatagramSocket - Java implementation of UDP protocol User Datagram Protocol (UDP) is more suitable for such streaming applications like Microphone-service.

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SLIDE 4

Microphone-service: Knowledge Processor

Service is implemented as a single KP SmartSlog: SDK for KP development Ontology: service representation model (OWL, RDF)

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SLIDE 5

Microphone-service: Workflow Scheme

1 Initialization 2 Publishing address 3 Listening for connections 4 Receiving and

processing data

5 Playing audio flow

Development: Microphone-service KP (server) and Client KP

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SLIDE 6

Android Client: Architecture

User interface Java-based module uses Android SDK JNI enables Java to use native implementations Application logic is C written and supported by Android NDK SmartSlog supports

ntology-driven implementation:

◮ publication and extraction data ◮ subscription mechanism ◮ connection state tracking Pavel Kovyrshin Microphone Service for SmartRoom FRUCT15 6 / 11

SLIDE 7

Android Client for SmartRoom: User Interface

Mobile device becomes a microphone Users: current speaker and chairman

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SLIDE 8

Performance Experiments

Wireless network quality strongly influences on service performance. Network transmission Audio processing Average Standard deviation ¯ τ = 50 ms σ = 6 ms ≈ 15 ms

Figure: Transmission time of 500 UDP packets of 62 bytes

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SLIDE 9

Performance: Our Solutions

Audio processing: JSpeex codec

◮ based on CELP algorithm ◮ well-suited to handle VoIP ◮ suitable for unreliable transfer packets network

UDP for real-time audio transfer Router configuration: selection of less used network channel

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SLIDE 10

Metrics of Implementation

Client side Server side Java code, loc. 138 293 C code, loc. 91 84 Devices Samsung Galaxy S3 Notebook Asus x200ca D-Link DIR-320 router Tools SmartSlog SDK, JSpeex Android SDK/NDK, JNI

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SLIDE 11

Conclusion

Released server (Linux) and client (Android) KPs Performance: solutions and experimental evaluation SourceForge:

http://sourceforge.net/projects/smartroom/ files/services/microphone-service/

Project Wiki:

http://oss.fruct.org/wiki/SmartRoom

Android client:

http://play.google.com/store/apps/details ?id=petrsu.smartroom.android.srclient My e-mail: kovyrshi@cs.karelia.ru

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