Cheri Perception

Hubert Pan

Cathy Zhang

Bryan Cua

Tilson Chung

Product Overview

Operation

Simulation

Statistics

Prototype

Future Development

Product Overview

VBSS Voice over IP Bandwidth Saving System

Product as Dynamic Operator

Paper Cup Analogy

Reduce operation costs

Minimize network resource usage

Pioneer dual voice stream compression

EXISTING TECHNOLOGY

Single stream compression

VBSS PRODUCT

Dual stream compression

Designed on top of single stream compression

Operation

John

Alex

Jill

Alice

John

Alex

Jill

Alice

Big Pipe (Internet)

John

Alex

Jill

Alice

Big Pipe (Internet)

Voiced

Unvoiced

Silent

Simulation

MATLAB, C++

Pulse Code Modulation

Voice recorded Webcam Microphone

Formant Estimation

Fundamental Frequency Estimation

Linear and nonlinear filters

BEFORE AFTER

Prototype

A small network support up to 6 devices

4 Grandstream VoIP phones

PC

FPGA board (Xilinx XUP-V2P)

Hardware (Xilinx XUP-V2P): 32-bit MicroBlaze processor Low-Frequency On-Chip Peripheral Bus (OPB) Fast Simplex Link Bus (FSL) Fast Fourier Transform G711 μ-law codec

Statistics

Frames

Packet

Packet (pkt) Size

= 218 bytes/pkt = 1744 bits/pkt

Data Packets arrive every 20 ms (λi = 1 for each phone)

λT = = = 200 pkt/s

= 348800 bits/s

4

1ii

ms

pkt

20

4

20 ms

μT ≈ for 2 pkt

s / packet packet/ms

ms ms

4.260 84.3

0.04) 0.654 0.214 (0.4322 5

C = Packet Service Rate × Average Packet Length = (260.4 packets/s) × (1744 bits/packet) = 0.454 Mbps

Processing Time Line for One Phone

Packet Processing

Time Division

10/100 Mbps switch accommodates the system capacity

System Utilization = 0.454 Mbps ÷ 10 Mbps = 4.54%

Traffic Intensity = ρ = λT ÷ μT ≈ 76.8 %

Type of Frame % of Frames

Combined ~ 60%

Overall Saving ~ 30%

Voiced ~ 90%

Unvoiced ~ 10%

Module Time

Autocorrelation 0.432ms

PEF 0.654 ms

Send Packet Function 0.0425ms

MLP 0.214ms

Speech Characteristic

Module-added Delay

Future Development

Simulation vs Prototype No packets Clear-cut frames Calculation Precision

Prototype Environment too different from reality Single network port board Lone product Low interference

Robustness

Problems Thresholds Background noise Noise between frames

Processing power

Network Interfaces

Professors Lakshman OneSteve WhitmoreLesley Shannon