GB2598326A

GB2598326A - Method to connect bluetooth slaves to a bluetooth broadcaster with NFC

Info

Publication number: GB2598326A
Application number: GB2013320.3A
Authority: GB
Inventors: Geoffrey Ma Qingping
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-08-26
Filing date: 2020-08-26
Publication date: 2022-03-02
Also published as: GB202013320D0

Abstract

A method of wirelessly connecting slave devices to a master device using NFC comprises a system to relay information necessary to connect a CSB transmitter to a CSB receiver, devices capable of reading/receiving data from a static NFC tag and using this device to connect to a CSB and a device or system capable of transmitting a CSB signal and providing a connection and codec information.

Description

Intellectual Property Office Application No G132013320.3 RTM Date:19 February 2021 The following terms are registered trade marks and should be read as such wherever they occur in this document: Bluetooth, CELT, atpX Intellectual Property Office is an operating name of the Patent Office www.gov.uk/ipo Method to connect Bluetooth slaves to a Bluetooth broadcaster with NFC

Field of Invention

This invention relates to a new and improved way for the connection of Bluetooth Audio devices to a master device using Near Field Communication.

Background

Although mobile communication devices have developed dramatically in the past 20 years and billions of such devices are in current use, they are used mainly for voice communications and social media access. There is great potential to put billions of such devices into better use.

One common peripheral device for a host device (computers, mobile phones, tablets, dedicated communication devices and even MP3/4 players) is the Bluetooth audio device (which includes, but is not limited to: speaker(s), headphone(s), earphone(s), headphone and microphone, headphone and microphone and video display). Bluetooth audio devices have become a staple of modern living.

The fact that one host device can link easily to only one Bluetooth audio device has limited the application of such technology. There are several technical concerns when trying to connect multiple Bluetooth audio devices to a single host device. Historically, this has mainly been latency issues and configuring a host to connect securely to a plurality of receivers.

The latency issue has been addressed by development of codecs such as Constrained Energy Lapped Transform (CELT) or AtpX Low Latency. The "Comiectionless Slave Broadcast" (CSB) feature described in the Bluetooth Specification allows a single master (CSB transmitter) to broadcast to an unlimited number of receivers (CSB receiver). Audio can be transmitted to a large number of Bluetooth Audio devices using packets transported with the CSB feature; with a suitable audio codec. A practical realization of such a system is Qualcomm Broadcast Audio technology. The latter is a high leve technology designed for 'one to many' audio streaming which high levels of synchronization.

This patent offers a solution for one host device to connect with multiple Bluetooth peripheral devices quickly and effectively.

Broadly -the traditional method of connection is either to provide a host device with a Bluetooth Address with which to communicate, or to use traditional Bluetooth device and service discovery ('pairing model Some peripheral devices have a NFC chip to provide the address information (active devices can also exchange security information for an out of bandwidth pairing), and some devices have been known to have their Bluetooth Addresses stored in a cloud database. In either case, these require the host device to commence the connection action.

Clearly, none of these solutions is ideal in die context of pairing a large number of peripheral devices to a single 'host' (transmitter) device. We present a solution to this problem.

Description of Invention

The invention consists of 4 elements, one or a combination of more than one of these four elements can be used to realize the purpose of this invention.

1 A system to relay information necessary for a CSB receiver to connect to a CSB transmitter. Methods to relay this information, include but are not limited to, online exchange and near field communication.

2 A device, devices or systems capable of reading/receiving data from a static NFC tag or other NFC device, and using this device to connect to a CSB. This includes data required to decode received data into audio data (such as codec and/or encryption information).

3 A device, devices or system capable of transmitting a CSB signal, and providing connection and codec information in a format that can be transmitted: online, directly to a NFC receiver, to an intermediary device, or to a static NFC tag.

4. Any intermediary devices or systems to relay the data described above.

The host transmitting device will use the CSB feature of the Bluetooth Protocol to transmit audio and/or data and/or video, having first been processed by some codec (such as CELT or AtpX). The CSB feature allows the device to communicate with an unlimited number of receivers. Similar to asynchronous devices, receivers do not need to confirm that packets are received. Connecting devices will need to scan the 'synchronization physical channel' in order to acquire timing and frequency information. The detailed connection process is written in the Bluetooth Core Specification (v5.2) and therefore is not repeated in this text.

The host (transmitting device) will send all information (data) necessary for a slave (receiving device). This will include data which instructs the slave device to connect to the connectionless slave broadcast; and to use the synchronization channel to recover the clock. It will also contain codec information -needed to decode data in the packets. There are different methods to do this. This information will either be sent directly to the slave via NFC, or via an intermediary (see below).

There are 3 primary modes in which the host device can pass connection and codec information to a slave (receiver): I The host device (e.g a smartphone) will use its NFC chip to communicate connection and codec information to a receiving device. The receiving device will then use this information to connect to the transmitting CSB; and then decode received data.

2 The host device (e.g. a smartphone) will use its NFC chip to communicate connection and codcc information to an intermediary device -e.g. a NFC tag. The receiving device will then read the tag, and use this information to connect to the transmitting CSB and decode received data.

3 The host device (e.g. smartphone) will send connection and codec information to one (or more) intermediaries. This may be via the world wide web. An intermediary device (such as a different smartphone) can then send the connection and codec information to the headphones. A simple diagram showing a simple example is shown in Figure 3.

Upon receipt of the connection and codec information, the receiver device will use this information to connect to the CSB. Upon connection, the codec information will be used to turn the received Bluetooth data into audio and/or data and/or video.

The connection information (specifically the Bluetooth Address of the transmitting device) provided via NFC is equivalent to attaining the information via the 'paging' process described in the Bluetooth Core Specification (v5.2).

In order for the receiver device to receive packets; it must first synchronize with the transmitter. The CSB master transmits frequent synchronization packets (identifiable by the Bluetooth address) on the Synchronization Scan Channel. The slave listens for synchronization packets (often referred to as the synchronization train) with the correct Bluetooth address -in order to synchronize its dock with the master clock; and acquire frequency hopping patterns. With this information, the slave (receiver) can receive Coimectionless Slave Broadcast Packets broadcast by the host; using host controller interface protocols.

Once connected, the slave (receiver) can then decode the received data into audio and/or data and/or video. A simplified overview of the whole process is highlighted in Figure 1. (Figure la shows passing info directly from host to slave over NFC. Figure lb shows the use of a NFC tag to hold the information.) In cases where the host device communicates with the slave device directly over NEC; the synchronization process can be conducted over NFC. The host Bluetooth controller needs to pass the frequency infoimation over NFC to the slave Bluetooth controller. Synchronizing the slave clock is achieved by passing clock data from the host controller to the slave controller via NFC. Any time delays induced by NFC will need to be accounted for. This can, in circumstances, alleviate the need for the host device to broadcast on the Synchronization Sean Channel. Figure 2 shows a simplified version of this process.

Connection and codec information will include encryption information (where appropriate), and information needed to interpret upper layers (if appropriate).

By passing codec information (via NFC) -e.g. encryption keys, codec name and parameters -directly to the slave (receiver) device, there is no need to use space in the broadcast frame to transfer this information. This has potential to increase the data rate.

Audio and/or data and/or video will be carried in packets transmitted by the broadcaster.

In the case of speakers, the receiver device will play audio with a speaker. In the case of headphones, the receiver device will play audio though headphones. Another device is a receiver with an 'audio out' port -e.g. 3.5mm jack to allow incompatible devices to receive audio signal.

The device or system communicating connection and codec information need not be the same as the transmitting device.

Application Examples

I. individual speakers (possibly from different manufacturers) with this technology can play audio from the transmitting device in a synchronized manner. A 'tap' between the NFC chips between the transmitter and receiver is all that is required.

2. Silent disco -connection information can be put on NFC tags or stickers available at a venue -participants can bring their own headphones. Connection is as simple as tapping the headphones' NFC chip against a pre-coded NFC tag. If the silent disco has multiple 'channels', a tap against the respective tag is all that is needed to change channel.

3. Interactive advertising -a poster could have a readable NFC chip with the connection/codec information for a nearby C5B transmitter.

4. Ballroom dancing -similar mode of operation as silent disco, except the transmitting device (e.g. smartphone or MP3 player) will communicate directly with the headphones over NFC. This way, both dance partners will hear the same synchronized music.

5. Watching TV/films in areas where noise is restricted. The TV could, say, be the transmitter presenting an easy solution for multiple people to hear the audio in a synchronized manner.

Abbreviations CSB -Connectionless Slave Broadcast

NFC -Near Field Communication

CELT -Constrained energy lapped transform Definitions Connect -synchronize to the same frequency hopping and clock.

Packet/frame/message are used exchangeable.

Connection and code information -includes any data or parameters that can be used to establish a commimications connection; receive data; and decode/decrypt that data. This may include higher level Bluetooth information -such as packet format.

NFC includes all RFID (Radio Frequency Identification) technology.

Claims

Claims I Systems, hardware, software or algorithms that: a. Allow Bluctooth slave devices (e.g. Bluetooth headphones or speakers) to use NEC to receive connection and codec information via NFC or an NFC tag.b. Uses the received information (over NEC) to connect to a host device broadcasting Connect onless Slave Broadcast packets.Connect includes the synchronization process using a synchronization train.c. Uses the codec/encryption/other information received over NFC to demypt/render audio/video/data from the broadcast frames.d. Allows a slave to synchronize (its clock and frequency information) via NEC with the broadcasting device.e. Enables Bluetooth connection and codec information to be generated in such a form that it can be communicated via NEC.
2 The connection as in claim I achieved by using NFC reader on the peripheral device to receive data from the NEC chip on the host device.
3 The connection as in claim I achieved by using NEC reader on the peripheral device to read information from a NEC tag.
4 The connection as in claim I achieved by exchanging decoding and codec information between the NFC chip with reader on peripheral device and NFC chip with reader on the host device.
The use of any intermediary device(s) for all of the claims above, including the communication of connection/codec/encryption data over the world wide web.
6 The design, manufacturing, programming, distribution and use of device/system specified in claims 1-5.
7 Further development/modification of device based on or derived from the device, hardware or software based on claims 1-5.S. The use of the methodology in claims 1-5 with any wireless communications protocol.