High sound quality & low -delay Bluetooth "LE Audio" Appears soon? Sony explains technical explanation

Bluetooth Sig held the Bluetooth Tokyo Seminar 2021 on the 18th, which explains related latest technology and innovation.At the event, Mr. Masahiko Seki, who participates in the standardization of Bluetooth Sig as Sony, gave a lecture, explaining the new standard "LE Audio" (LE Audio).

LE Audio is a new Bluetooth audio standard that is expected to be mounted on wireless earphones and smartphones to be released in the future.

It was announced in January 2020 as a redefinition of the conventional Bluetooth audio (Classic Audio), which has been used for a long time, and will soon be the official version of all specifications required for LE audio (currently some profiles).Waiting for the final formulation of the specifications).

Bluetoothオーディオ規格の変遷LEオーディオの特徴

LE Audio features a high sound quality and low delay by using a new audio codec and transmission method that is different from the past.

LC3 is used as its standard codec.The latest audio codec developed mainly by the German Frown Hoofer Research Organization, and is possible to achieve the same sound quality at a low bit rate compared to SBC, which is the standard codec of A2DP.

According to the actual survey, when comparing the 345kbps SBC audio and the 160kbps LC3 audio, the low -bit rate LC3 had a higher sound quality evaluation score.

LEオーディオの標準コーデックは「LC3」

In LE audio, it supports multi -streams of left and right independent transmission.Left and right independent transmission, which had been unique to each company, such as TWS+of Qualcomm and MCSync of Airoha, has been standardized in LE audio.

In addition, a broadcast function that can be transmitted simultaneously to a large number of people has been added.For example, simultaneously transmitting from a TV to multiple headphones, the same content can be enjoyed by multiple people.This feature is expected to be used in theaters and stores, as well as announcements in places such as square, station and airports.

LEオーディオのユースケース

Bluetooth 5 in LE audio.2 (Core Version 5.2) Two functions adopted, "LE ISochronous Channels" and "Enhanced Attribute Protocol (Eattt)" are required.The former is a communication method for transmitting LE audio, and the latter is an extension of ATT so that multiple ATT PDU can be communicated simultaneously.

Among them, the key is Le Isochronous Channels.The multi -stream and broadcast function mentioned above are realized by adopting this new streaming method, and low -delay transmission is possible by sending audio data in time for each interval (the conventional A2DP is asynchronous).。

LEオーディオでは「LE Isochronous Channels」と「Enhanced Attribute Protocol(EATT)」が必要になるLE Isochronous ChannelsLEオーディオのスタック構成Generic Audio Frameworkプロファイル

講演したソニー HE&Sプロダクツ事業本部 モバイルプロダクト事業部 モバイル商品技術2部 パートナー技術課 ワイヤレステクニカルマネージャーの関氏は、ソニーが初期からBluetooth SIGでのLEオーディオ規格化活動に参画し、早期の仕様策定完了を目指して活動してきたことをアピール。

The reasons for Sony needed LE audio include "realization of difficulty in SBC, stable transmission at low bit rate, multi -streams that do not depend on platforms, new user experience with broadcast".

ソニーが考えている、LEオーディオの進化例

Furthermore, as the evolution of LE audio, which is expected in the future, as an example, as an example of further low -delay standards that can withstand the use of games, correspondence to spatial audio, higher sound quality due to bandwidth, and multi -channel surround support.He introduced, "I think it would be better to proceed with standardization so that these functions could be realized."

After the lecture, the listener asked the question, "When Sony is planning to release LE audio -compatible products," said Seki, "I would like to refrain from talking about specific products.I want to do it as soon as possible. "