Wideband-AMR validation and testing was conducted over 3G networks. Wideband audio from 50-7000 Hz provides improved speech quality, naturalness, and intelligibility compared to narrowband audio from 200-3400 Hz. The test involved comparing wideband and narrowband audio streams for various audio clips and analyzing frequency responses. Results showed wideband captured higher frequencies and had better adaptive noise cancellation and audio quality. Testing also validated seamless switching between wideband and narrowband during 3G to 2G handovers.

1. Wideband-AMR
Validation and Testing over
3G Network
Dr. Ayman Elnashar
Sr. Director - Wireless Broadband & Site Sharing
Ayman.elnashar@du.ae
Dr. Mahmoud Sherif
Director – Wireless Broadband
Kassem Abdulla
Sr. Manger – Wireless Broadband
Thanks for the support of the Wireless Broadband Team

2. Background Information
Bandwidth of sound signals:
- Regular telephone bandwidth (Narrowband) = 200-3400 Hz
- Wideband (wider bandwidth) = 50-7000 Hz
Why Wideband:
- Results in major subjective improvements in speech quality
- Compared to narrowband telephone speech, the low-frequency enhancement
from 50 to 200 Hz contributes to increased naturalness, presence, and comfort.
- The high-frequency extension from 3400 to 7000 Hz provides better fricative
differentiation and therefore higher intelligibility.
- A bandwidth of 50 to 7000 Hz not only improves the intelligibility and
naturalness of speech, but also adds a feeling of transparent communication
and facilitates speaker recognition.
Source  VoiceAge WHITE PAPER
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3. Wideband-AMR
Technical Specification: 3GPP TS 26.171 V7.0.0 (2006-09)
The AMR-WB speech coder consists of the multi-rate speech coder, a source
controlled rate scheme including a voice activity detector and a comfort noise
generation system, and an error concealment mechanism to combat the effects of
transmission errors and lost packets.
The multi-rate speech coder is a single integrated speech codec with nine source
rates from 6.60 kbit/s to 23.85 kbit/s, and a low rate background noise encoding
mode. The speech coder is capable of switching its bit-rate every 20 ms speech
frame upon command.
Codec mode Source codec bit-rate
- AMR-WB_23.85 23.85 kbit/s
- AMR-WB_23.05 23.05 kbit/s
- AMR-WB_19.85 19.85 kbit/s
- AMR-WB_18.25 18.25 kbit/s
- AMR-WB_15.85 15.85 kbit/s
- AMR-WB_14.25 14.25 kbit/s
- AMR-WB_12.65 12.65 kbit/s
- AMR-WB_8.85 8.85 kbit/s
- AMR-WB_6.60 6.60 kbit/s
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4. Speech Quality Comparison
Speech quality of AMR-WB in the GSM FR channel compared to AMR-NB and EFR
Source  VoiceAge WHITE PAPER
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5. Sample Handset With WB-AMR Support
Supported Handsets
Vendor
Current
Nokia N8
Sony Ericsson Elm, Hazel, Cedar
Samsung SIII, Galaxy Note 2
Apple IPhone 5
 It has to be noted that, some of existing Symbian phones like
E72 support WB-AMR but was not enabled by Nokia.
Therefore, to activate WB-AMR in these phones a firmware
upgrade is needed.
 It is to be noted that some handset manufactures turn off the
WB-AMR feature and they only enable it upon operator
request.
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6. 3GPP Schematic diagram for WB-AMR (TX)
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7. Wideband Versus Narrowband:
A Comparative Analysis
based on live network results
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8. Test-bed: Test Setup
Node-B/RNC/MGW
RX Station
TX Station
Audio output Streams
Audio Input Streams
WB-UE
Nokia N8
WB-UE Adobe Audition Recorder
Nokia E72
MP3 Source Files with WB frequencies
Adobe Audition Ver 3.
Post Processing &
Verification Tools Suit
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9. Audio Source for Testing
Source Audio (Test Audio) has been very carefully chosen based on the “Test
Vectors Associated to Rec. ITU-T G.722.2 Annex D” and consists of the following:
Phonetically Phonetically High-to-Low Low-to-High MP3 HiFi
Balanced Speech Balanced Speech Frequency Frequency Song
with Background without Scan Scan (0-17KHz)
Noise (Rain) Background Noise (50-7000Hz) (50-7000Hz)
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10. Wideband versus Narrowband Real-Time Streams
High Frequency Cutoff with NB High Frequency Pass with WB
Narrow Band output
Wide Band output
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11. WideBand & NarrowBand-Frequency Analysis
Narrow-Band Cut-off Frequency
Wide-Band Cut-off Frequency
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12. WB versus NB Real-Time Series:
Phonetically Balanced Speech with Noise Background(Rain):
Time-Series
NB Output
NB_Rain_MP3.mp3
WB Output
Much better Adaptive Noise Cancellation Algorithm
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13. WB versus NB Frequency Analysis:
Speech with Noise Background (Noise)
Narrow-Band Cut-off Frequency : Narrower Filter
Wide-Band Cut-off Frequency: Wider Filter
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14. WB Versus NB Real-Time Series:
Phonetically Balanced Speech without Background Noise, but with Female Sound.
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15. WB Versus NB Frequency Analysis:
Phonetically Balanced Speech without Background Noise, but with Female Sound.
Narrow-Band Cut-off Frequency
Wide-Band Cut-off Frequency
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16. WB Versus NB Real Time Series: Low-to-High Frequency Scan
Narrow-Band Output
Wide-Band Output
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17. WB Versus NB –Frequency Analysis: Low-to-High Frequency Scan
Narrow-Band Cut-off Frequency
Wide-Band Cut-off Frequency
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18. WB Versus NB –Real Time Series: MP3 Music
Narrow Band Output
Wide-Band Output
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19. WB Versus NB –Frequency Analysis: MP3 Music
Narrow-Band Cut-off Frequency
Wide-Band Cut-off Frequency
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20. WideBand to NarrowBand Switching during
3G to 2G call Handover test-case
3G to 2G Handover
3G 2G
Handover Mute < 200ms Requirement
Wide-Band Narrow-Band
156 millisecond 20

21. WideBand (on 3G) Frequency Analysis
(Before 2G Handover)
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22. NarrowBand -Frequency Analysis
(After 2G Handover)
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23. Thank You
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