Enhanced Voice Services (EVS) is a superwideband

speech Speech is a human vocal communication using language. Each language uses phonetic combinations of vowel and consonant sounds that form the sound of its words (that is, all English words sound different from all French words, even if they are th ...

audio coding standard An audio coding format (or sometimes audio compression format) is a content representation format for storage or transmission of digital audio (such as in digital television, digital radio and in audio and video files). Examples of audio coding f ...

that was developed for

VoLTE Voice over LTE (VoLTE) is an LTE high-speed wireless communication standard for mobile phones and data terminals, including Internet of things (IoT) devices and wearables. VoLTE has up to three times more voice and data capacity than older 3G ...

. It offers up to 20 kHz audio bandwidth and has high robustness to delay jitter and packet losses due to its channel aware coding and improved

packet loss Packet loss occurs when one or more packets of data travelling across a computer network fail to reach their destination. Packet loss is either caused by errors in data transmission, typically across wireless networks, or network congestion.Ku ...

concealment. It has been developed in 3GPP and is described i
3GPP TS 26.441
The application areas of EVS consist of improved telephony and teleconferencing, audiovisual conferencing services, and streaming audio. Source code of both decoder and encoder in ANSI C is available a
3GPP TS 26.442
and is being updated regularly. Samsung uses the term HD+ when doing a call using EVS.

History

Work on EVS was started in 2007. The standardization process lasted from 2010 to 2014, being completed in December 2014 with 3GPP Release 12.The 3GPP Enhanced Voice Services (EVS) codec.
Nokia white paper. The codec was developed collaboratively among chipset, handset and infrastructure manufacturers as well as operators and technology providers.Enhanced Voice Services (EVS) Codec
Fraunhofer Technical Paper, 2015

GSMA The GSM Association (commonly referred to as 'the GSMA' or ''Global System for Mobile Communications'', originally ''Groupe Spécial Mobile'') is an industry organisation that represents the interests of mobile network operators worldwide. More ...

requires EVS for their HD Voice+ Logo Licensing Program. The six patent holders are Fraunhofer IIS, JVC Kenwood,

Nippon Telegraph and Telephone , commonly known as NTT, is a Japanese telecommunications company headquartered in Tokyo, Japan. Ranked 55th in ''Fortune'' Global 500, NTT is the fourth largest telecommunications company in the world in terms of revenue, as well as the third la ...

, NTT Docomo,

Panasonic formerly between 1935 and 2008 and the first incarnation of between 2008 and 2022, is a major Japanese multinational conglomerate corporation, headquartered in Kadoma, Osaka. It was founded by Kōnosuke Matsushita in 1918 as a lightbulb ...

, and

Ericsson (lit. "Telephone Stock Company of LM Ericsson"), commonly known as Ericsson, is a Swedish multinational networking and telecommunications company headquartered in Stockholm. The company sells infrastructure, software, and services in inform ...

. Other contributors included

Huawei Huawei Technologies Co., Ltd. ( ; ) is a Chinese multinational technology corporation headquartered in Shenzhen, Guangdong, China. It designs, develops, produces and sells telecommunications equipment, consumer electronics and various sma ...

Nokia Nokia Corporation (natively Nokia Oyj, referred to as Nokia) is a Finnish multinational telecommunications, information technology, and consumer electronics corporation, established in 1865. Nokia's main headquarters are in Espoo, Finland, i ...

, Orange,

Qualcomm Qualcomm () is an American multinational corporation headquartered in San Diego, California, and incorporated in Delaware. It creates semiconductors, software, and services related to wireless technology. It owns patents critical to the 5G, ...

Samsung Electronics Samsung Electronics Co., Ltd. (, sometimes shortened to SEC and stylized as SΛMSUNG) is a South Korean multinational electronics corporation headquartered in Yeongtong-gu, Suwon, South Korea. It is the pinnacle of the Samsung chaebol, acc ...

, VoiceAge, and ZTE Corporation. A

patent pool In patent law, a patent pool is a consortium of at least two companies agreeing to cross-license patents relating to a particular technology. The creation of a patent pool can save patentees and licensees time and money, and, in case of blocking ...

for EVS has been listed by MPEG LA.

Technology

EVS employs similar concepts to its predecessors, such as

AMR-WB Adaptive Multi-Rate Wideband (AMR-WB) is a patented wideband speech audio coding standard developed based on Adaptive Multi-Rate encoding, using a similar methodology to algebraic code-excited linear prediction (ACELP). AMR-WB provides improved ...

, to which it retains backward-compatibility. It switches between speech and audio compression modes depending on the content, using

ACELP Algebraic code-excited linear prediction (ACELP) is a speech coding algorithm in which a limited set of pulses is distributed as excitation to a linear prediction filter. It is a linear predictive coding (LPC) algorithm that is based on the cod ...

and MDCT. The following features are present in EVS: * source-controlled variable bit-rate (SC-VBR) * voice/sound activity detector (VAD) * comfort noise generation (CNG) *

error concealment Error concealment is a technique used in signal processing that aims to minimize the deterioration of signals caused by missing data, called packet loss. A signal is a message sent from a transmitter to a receiver in multiple small packets. Packet ...

(EC) for packet loss in networks * channel-aware mode to improve frame/packet error resilience * jitter buffer management (JBM) Input sampling rates for EVS can be 8, 16, 32, and 48 kHz. It supports the following bitrates (in kbps) for different bandwidths: * Narrowband (NB): 5.9, 7.2, 8, 9.6, 13.2, 16.4, 24.4 * Wideband (WB): 5.9, 7.2, 8, 9.6, 13.2, 13.2 channel-aware, 16.4, 24.4, 32, 48, 64, 96, 128 (6.6 ~ 23.85 for AMR-WB IO) * Super-wideband (SWB): 9.6, 13.2, 13.2 channel-aware, 16.4, 24.4, 32, 48, 64, 96, 128 * Fullband (FB): 16.4, 24.4, 32, 48, 64, 96, 128 Bitrates can be switched every 20 ms. Subjective listening tests conducted by Nokia concluded that EVS offers significantly improved quality over AMR and

at all operating points.

Adoption

Operators which have launched EVS powered

services include: * NTT DoCoMo * T-Mobile USA * T-Mobile Polska *

Vodafone Germany Vodafone GmbH is a mobile telecommunications operator in Germany headquartered in Düsseldorf. It provides mobile phone, LTE, 5G, cable internet, landlines, cable TV, and IPTV services. As of the third quarter of 2021, Vodafone GmbH has more ...

Vodafone Romania Vodafone Romania S.A. is a Romanian mobile phone network operator. It launched in April 1997 as the first GSM network in Romania. Before acquisition by Vodafone, it was known as Connex, after which it was rebranded Connex-Vodafone and in Apr ...

* Orange Romania *

Orange France Orange S.A. (), formerly France Télécom S.A. (stylized as france telecom) is a French multinational telecommunications corporation. It has 266 million customers worldwide and employs 89,000 people in France, and 59,000 elsewhere. In 2015, ...

Free France Free France (french: France Libre) was a political entity that claimed to be the legitimate government of France following the dissolution of the Third Republic. Led by French general , Free France was established as a government-in-exile ...

SK Telecom SK Telecom Co., Ltd. ( or ) is a South Korean wireless telecommunications operator and former film distributor and is part of the SK Group, one of the country's largest chaebols. It leads the local market with 50.5 percent share as of 2008. ...

* KT Corporation * LG Uplus *

Deutsche Telekom Deutsche Telekom AG (; short form often just Telekom, DTAG or DT; stylised as ·T·) is a German telecommunications company that is headquartered in Bonn and is the largest telecommunications provider in Europe by revenue. Deutsche Telekom was ...

* KDDI Japan *

China Mobile China Mobile is the trade name of both China Mobile Limited () and its ultimate controlling shareholder, China Mobile Communications Group Co., Ltd. (, formerly known as China Mobile Communications Corporation, "CMCC"), a Chinese state-ownedSt ...

* EE United Kingdom * Vodafone Netherlands * KPN Netherlands *

Airtel India Airtel India is the second largest provider of mobile telephony and third largest provider of fixed telephony in India, and is also a provider of broadband and subscription television services. The brand is operated by several subsidiaries o ...

* A1 Telekom Austria * 3 Austria *

Swisscom Swisscom AG is a major telecommunications provider in Switzerland. Its headquarters are located in Ittigen near Bern. The Swiss government owns 51.0 percent of Swisscom AG. According to its own published data, Swisscom holds a market share of ...

Verizon Communications Verizon Communications Inc., commonly known as Verizon, is an American multinational telecommunications conglomerate and a corporate component of the Dow Jones Industrial Average. The company is headquartered at 1095 Avenue of the Americas in ...

Turkcell Turkcell İletişim Hizmetleri A.Ş. (''lit. Turkcell Communication Services'') (, ) is the leading mobile phone operator of Turkey, based in Istanbul. The company has 39,3 million subscribers as of September 2021. In 2015, the company's number o ...

* TIM *

Wind Tre Wind Tre S.p.A. (formerly H3G S.p.A.) is an Italian telecommunications company of the CK Hutchison Holdings Limited group, which offers mobile and fixed telephony services. It began as a mobile telephone operator in 1999, with the name ''A ...

* Vodafone Idea (V!) India * Telekom Hungary *

Telenor Hungary Yettel Hungary (formerly ''Telenor'', ''Pannon'' and ''Pannon GSM'') is the second largest mobile phone operator in Hungary. Yettel Hungary Ltd. was founded as ''Pannon GSM Telecommunications Ltd.'' in 1994. History In November, 1993 Pannon GSM ...

Vodafone New Zealand Vodafone New Zealand Limited is a New Zealand telecommunications company. It was a subsidiary of the London-listed company Vodafone Plc until 31 July 2019, when its sale to a consortium comprising Infratil Limited and Brookfield Asset Manageme ...

* Magyar Telekom Currently there are about 200 models from different smartphones manufacturers supporting EVS, including: *

Apple An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple trees are cultivated worldwide and are the most widely grown species in the genus '' Malus''. The tree originated in Central Asia, where its wild ancest ...

Samsung The Samsung Group (or simply Samsung) ( ko, 삼성 ) is a South Korean multinational manufacturing conglomerate headquartered in Samsung Town, Seoul, South Korea. It comprises numerous affiliated businesses, most of them united under the ...

Google Google LLC () is an American Multinational corporation, multinational technology company focusing on Search Engine, search engine technology, online advertising, cloud computing, software, computer software, quantum computing, e-commerce, ar ...

HTC HTC Corporation ( zh, t=宏達國際電子股份有限公司, s=宏达国际电子股份有限公司, p=Hóngdá Guójì Diànzǐ Gǔfèn Yǒuxiàn Gōngsī, first=t) or High Tech Computer Corporation, (literally ''Hongda International Electron ...

* LG *

Motorola Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois, United States. After having lost $4.3 billion from 2007 to 2009, the company split into two independent public companies, Motorola ...

Sony , commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...

Xiaomi Corporation (; ), commonly known as Xiaomi and registered as Xiaomi Inc., is a Chinese designer and manufacturer of consumer electronics and related software, home appliances, and household items. Behind Samsung, it is the second largest ...

Interoperability

Inter-carrier interoperability is a problem, as calls are by default routed over narrowband type connections which downgrades the voice to narrowband quality vs EVS and HD Voice™️ even if the individual phones and carrier networks all support EVS. Interoperability was very limited in 2018 and remains so. Thus, users are advised to ditch phone calls for pure VoIP apps such as FaceTime,

Google Duo Google Duo is a proprietary voice over IP (VoIP) and videotelephony service developed by Google, available for Android, iOS and web browsers. It lets users make and receive one-to-one and group audio and video calls with other Duo users in ...

WhatsApp WhatsApp (also called WhatsApp Messenger) is an internationally available freeware, cross-platform, centralized instant messaging (IM) and voice-over-IP (VoIP) service owned by American company Meta Platforms (formerly Facebook). It allows use ...

Facebook Messenger Messenger is a proprietary instant messaging app and platform developed by Meta Platforms. Originally developed as Facebook Chat in 2008, the company revamped its messaging service in 2010, released standalone iOS and Android apps in 2011, and ...

, and/or

Telegram Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas ...

when voice call quality it poor despite good network connectivity.

Licensing

EVS, like AMR-WB and AMR-WB+, incorporates several

patents A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...

. As with those two codecs, VoiceAge Corporation is in charge of the licensing and offers RAND pricing

References

External links

Enhanced Voice Services Codec for LTE

The 3GPP Enhanced Voice Services (EVS) codec

Fraunhofer Technical Paper – Enhanced Voice Services (EVS) Codec
{{Compression formats Audio codecs Speech codecs Wideband codecs