February 6th, 2008
Face it: some cell calls suck. Study cites three reasons why
Just got a note in my very early (hey it isn’t quote 06:00 hours here) from a representative of Ditech Networks.
Raison d’etre for this post is that Ditech (no, not the mortgage finance firm) has just announced results of a 630-million-call study of live mobile phone calls over 16 mobile carrier networks in 12 nations.
The study reveals nearly 40% of mobile calls 
fall below industry minimum standards for voice quality. The report analyzed 630 million calls from 16 mobile carriers in 12 countries.
We have it better here. In the U.S. and Western Europe, some 23% of calls were flagged as falling below industry standards. Yet in India, the Middle East and Latin America, that figure was pegged at 59%.
The three biggest issues cited as reasons why mobile phone calls can be of dubious quality:
Ambient noise, or noise originating in caller’s environment and entering device’s microphone, was rated “objectionable” on up to 50% of all calls in some regions.
Acoustic echo, often caused by handsets/headsets, was rated “objectionable” on up to 11% of all calls in some regions.
Voice level mismatch, or when a caller sounds either too loud or too quiet, was rated “objectionable” on up to 28% of calls in some region.
If you are wondering about testing criteria, Ditech tells us:
The audits were conducted using Experience Intelligence (EXi), a technology developed by Ditech that quantifies the impact of voice quality impairments caused by the places where people make calls, codec impairments, and mobile devices like phones and headsets. EXi is based on the International Telecommunications Union (ITU) G.107 E-Model, a widely used industry standard, and the technology has been utilized in the communications industry as a complement to existing voice quality test and measurement solutions.
The audit data was used to derive an R-Factor, which is a 1-100 (best) rating system developed by the ITU to assess customer satisfaction with voice quality. The R-Factor was converted to a Mean Opinion Score (MOS), which is widely used in the mobile services industry to rate voice quality on a scale of 1 to 5 (best.) The ITU has set the minimum level of acceptable voice quality at R-Factor 50, or MOS 2.5. Voice quality that is rated below these minimums is considered unacceptable.
Cliche alert:
“Can You Hear Me Now?”
“Huh?”
“Wah?”
Russell Shaw is an enterprise computing journalist, analyst and author based in Portland, Oregon. See his full profile and disclosure of his industry affiliations.
