DESC:RELATED APPLICATION

Benefit is claimed to Indian Provisional Application No. 5632/CHE/2013 titled "METHOD AND SYSTEM FOR TRANSFERRING MEDIA OVER BLUETOOTH LOW ENERGY (BLE)" filed on 6th December 2013, which is herein incorporated in its entirety by reference for all purposes.

FIELD OF THE INVENTION
The present invention relates to the field of wireless communication, particularly to Bluetooth technology, and more particularly relates to method and system for transferring media over Bluetooth Low Energy (BLE) Protocol.

BACKGROUND OF THE INVENTION

Data transfer over the Bluetooth classic technology involves a high rate of power consumption. For instance, wearable devices like Bluetooth smart watch, head-set, hearing-aid has less processing power and limited battery source. Bluetooth low energy (BLE) is a wireless personal area network technology, which is intended to provide considerably reduced power consumption and cost while maintaining a similar communication range as that of Bluetooth classic. Therefore, data transfer over BLE is a better choice for afore said wearable devices.

The existing BLE technology has limited data rate and frequency. Hence,there are no adopted Bluetooth specifications which support an established media transfer like audio, video, image and text over BLE. The BLE can transfer only voice, low resolution videos, smaller images and text having very small size.Thus, transfer of high bitrate data over BLE is not possible.BLE for higher data rates is under researchto enable big data transfer over BLE.

Therefore, there exists a need of a method and system to transmit media data of moderate bitrate over Bluetooth Low Energy.

SUMMERY

The objective of present invention is to the transfer of media packets having a moderate bit rate over Bluetooth Low Energy (BLE).

Accordingly, one aspect of present invention teaches a method of transferring data using Bluetooth Low Energy (BLE) comprises generating one or more media packets having at least one media type as payload, assigning one or more logical link control and adaptation protocol channel identification(L2CAP CID) for the generated media packet based on the media type, transmitting the one or more media packets over one or more channels for which the one or more logical link control and adaptation protocol channel identification (L2CAP CID) assigned by a first device, receiving, by a second device, the one or more media packets transmitted by the first device and detecting the media type transmitted from the first device, based on the L2CAP CID of the one or more media packets by the second device. The media type comprises at least one of an audio, video, image and text. The media packets are conveyed to L2CAP layer of Bluetooth low energy as L2CAP SDUs in transmitting device. Likewise, the media packets are extracted from L2CAP layer as L2CAP SDUs in the receiving device.

According to the method of transferring data using Bluetooth low energy comprises transmitting the one or more media packets over one or more channel identification ranging from 0x0007 and 0x003E based on the media type.

The method of transferring data using Bluetooth low energy further comprises fragmenting media packets based on maximum size of a logical link control and adaptation protocol packet data unit (L2CAP PDU) and generating at least one L2CAP PDU by the first device before transmitting the media packet to the second device and reassembling the fragmented media packets by the second device after receiving the fragmented media packets in at least one L2CAP PDU to generate at least one L2CAP SDU. The media type for fragmenting and reassembling comprises at least one of a video, image, and text.

The reassembling the fragmented media type by the second device comprises identifying the media type being transmitted from the L2CAP CID assigned to each of the media packet, segregating one or more media packets based on the media type andforwarding one or more segregated media packets to one or more media subsystems based on the media type. The media subsystem in one embodiment of present invention comprises at least one of an audio subsystem, video subsystem, image subsystem and text subsystem.

Another aspect of present invention teaches a method of transferring data using Bluetooth low energy comprises assigning a logical link control and adaptation protocol channel identification (L2CAP CID) to one or more media packet based on media type, wherein the L2CAP CID ranging from 0x0007 and 0x003E, transmitting the one or more media packet by the first device to a second device using Bluetooth low energy (BLE) andrecognizing the transmitted one or more media packet by the second device based on the L2CAP CID assigned by the first device.

Yet another aspect of present invention recites a system for transferring data using Bluetooth low energy comprises a media subsystem comprises audio subsystem, image subsystem, video subsystem, and text subsystem, the media subsystem configured for performing one of a fragmenting media type based on size of the media type and generating at least one logical link control and adaptation protocol packet data unit (L2CAP PDU) andreassembling the fragmented media type by the second device after receiving the fragmented media type in at least one L2CAP PDU to generate at least one L2CAP SDU. Further the system comprises Bluetooth subsystem coupled to the media subsystem configured for generating one or more data packets having at least one media type as payload and assigning one or more logical link control and adaptation protocol channel identification(L2CAP CID) for the generated media packet based on the media type and detecting the media type transmitted from the first device, based on the L2CAP CID of the one or more media packets by the second device.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The aforementioned aspects and other features of the present invention will be explained in the following description, taken in conjunction with the accompanying drawings, wherein:
Figure 1 illustratesa schematic representation of transmission of data using wireless personal area network systemaccording to one embodiment of present invention.
Figure 2 illustrates a flow diagram of a method of transmission of media data over Bluetooth low energy (BLE) according to one embodiment of present invention.

Figure 3 illustrates a schematic representation ofa media packet transmitted over logical link control and adaptation protocol (L2CAP), according to one embodiment of present invention.

Figure 4 illustrates a schematic representation of data flow according to Bluetooth low energy protocol.

Figure 5 illustrates a block diagram of a schematic representation of Bluetooth low energy devices having Bluetooth subsystem and media subsystem.

DETAILED DESCRIPTION OF THE INVENTION
The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments. The present invention can be modified in various forms. Thus, the embodiments of the present invention are only provided to explain more clearly the present invention to the ordinarily skilled in the art of the present invention. In the accompanying drawings, like reference numerals are used to indicate like components.
The specification may refer to “an”, “one” or “some” embodiment(s) in several locations. This does not necessarily imply that each such reference is to the same embodiment(s), or that the feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments.
As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms “includes”, “comprises”, “including” and/or “comprising” when used in this specification, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations and arrangements of one or more of the associated listed items.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Figure 1 illustrates a schematic representation of transmission of data using Wireless Personal Area Network (WPAN)system 100 according to one embodiment of present invention. The system 100 includesa first device 101 and a second device 102. The first device and the second device are connected by a wireless network suchas WPAN. In one embodiment, the wireless personal area network is Bluetooth low energy (BLE) network.
In an example, the WPAN system 100 is configured for operating within a range of 0-100 meters. The first device 101 and the second device 102 are configured for communicating using BLE. The first device 101 and the second device 102 can be smart-watches, hands-free units, and hearing-aid devices. The device 101 and 102 use either coin cell batteries or rechargeable batteries with limited energy source.

According to conventional BLE environment, the device which advertises the supported services is called a Peripheral and the device which is interested in those services and initiates connection to the Peripheral is called a Central. For instance, in the present invention, the first device 101 is the peripheral and second device 102 is the central. There can be a service advertised by the second device also. In such cases, the second device acts as the peripheral and first device acts as the central.

Each service is uniquely identified by 128-bit universally unique identifier (UUID) which is defined by BLE and BLE facilitates in creating new services with user defined UUIDs. Each media type is assigned user-defined UUIDs. For example,media types such as audio, video, image and text services are assigned four different user-defined UUIDs.BLEalso facilitates to send manufacturer specific data in advertisement packet or scan response packet. The advertisement data types (AD types)are used for communicating service information. The payloads of media packets are defined based on AD types. For instance, AD type values to convey different and unique advertising units are given below:

0x02 - Incomplete List of 16-bit Service Class UUIDs
0x03 - Complete List of 16-bit Service Class UUIDs
0x04 - Incomplete List of 32-bit Service Class UUIDs
0x05 - Complete List of 32-bit Service Class UUIDs
0x06 - Incomplete List of 128-bit Service Class UUIDs
0x07 - Complete List of 128-bit Service Class UUIDs
0x14 - List of 16-bit Service Solicitation UUIDs
0x15 - List of 128-bit Service Solicitation UUIDs
0xFF - Manufacturer Specific Data

In an exemplary embodiment, the firstdevice 101 advertises audio, video, image and text over BLE capability using service UUIDs or manufacturer specific data. Upon discovering audio, video, image, text over BLE capability, the second device 102 initiates the connection to first device 101 for one or moremedia services.

Figure 2 illustrates a flow diagram of a method of transmission of media type Bluetooth low energy (BLE) according to one embodiment of present invention. The flow diagram illustrates the method steps involved in transmitting media type over BLE between the first device 101 and second device 102 upon identifying the service advertised by the first device 101.

At step 201, the first device 101 advertises the services available with the first device. At step 202, the second device 102 identifies the required services based on the preference of user. Once the services to be transferred are identified, a connection is established between the first device 101 and the second device 102 as indicated in step 203. Further, the first device 101 determines the size of the media type to be transmitted. According to one embodiment of present invention, the media data to be transferred is logical link control and adaptation protocol service data unit (L2CAP SDU).If the size of the media data exceeds a pre-defined size, then the media datais fragmented as shown in step 204. According to one embodiment of present invention, the size of the media datathat can be transmitted depends on the maximum payload size of L2CAP PDU.

At step 204, one or more media packets are generated. Thegenerated mediapacket in one embodiment of present invention is logical link control and adaptation protocol packet data unit (L2CAP PDU). Each fragment of the media type is allocated to one or more L2CAP PDU based on the maximum size of payload of the L2CAP PDU. The media types that can be fragmented are video, image and text. If one media type is fragmented, then a logical link ID (LLID) of data channel protocol data unit (PDU) is assigned.

The LLID of data channel PDU header is used for fragmentation and reassembling of video, image or text data.

LLID = 1 0 – Start of an L2CAP message / Complete L2CAP message
LLID = 0 1 – Continuation fragment of an L2CAP message.

For instance, consider that the media type is fragmented into two portions. Then then the LLID for the first PDU is assigned as 10 and LLID for the second PDU is assigned as 01.

The audio packets are transmitted in such a way that entire audio frame or multiple audio frames is fit into single L2CAP PDU and set the LLID of data channel PDU to 10. The audio module in the receiving device processes audio payload received from L2CAP as single or multiple audio frames. But, one audio frame cannot be split and transferred using multiple L2CAP PDUs.

Likewise, if the size of the text to be transmitted is less than or equal to the allowed payload size in a L2CAP PDU, entire data is sent as part of single L2CAP PDU. Otherwise, data fragmentation is performed.

Video and Image frames having high data rate may not be able to transmit over a single L2CAP PDU. Therefore, data fragmentation is used while dealing with video and image data.

At step 206, the first device 101 assigns logical link control and adaptation protocol channel identifiers (L2CAP CID) to each data packets. The L2CAP CID identifies the end point of the logical channel. Few L2CAP CIDs are reserved for specific purposes and few L2CAP CIDsare dynamically allocated. The channel allocation of L2CAP CID according to BLE specification is listed below.

0x0001 – L2CAP signaling channel
0x0002 – Connectionless channel
0x0003 – AMP manager
0x0004 – Attribute protocol
0x0005 – BLE L2CAP signaling channel
0x0006 – Security Manage
0x0007 ~ 0x003E – Reserved/Unused channels
0x003F – AMP test manager
0x0040 ~ 0xFFFF – Dynamically allocated channels

Particular media types are assigned particular L2CAP CID. This enables the detection of media type easy. According to one embodiment of present invention, the reserved or unused channels 0x0007 ~ 0x003E are used formedia packet transmission. At step 207, the media packets are transmitted by the first device 101, over the allocated channels ranging from 0x0007 ~ 0x003E to the second device.
At step 208, the second device 102 receives the media packet transmitted by the first device 101.
At step 209, the received media packets are reassembled by the second device 102. The process of reassembling is performed only for the fragmented media types. The fragmented media type is identified based on L2CAP CID and reassembled based on LLID.
Audio, video, image text modules located in the second device 102 opens the L2CAP channel with L2CAP CID based on the services communicated in advertising report. If the first device 101 advertises only image service, image subsystem in second device 102opensthe L2CAP channelwith L2CAP CID assigned for image type. If peripheral advertises multiple media capabilities, media module in second device102 may open L2CAP channels with the first device for one or many media types. L2CAP CIDs are selected from reserved L2CAP CID i.e. 0x0007 ~ 0x003E.

Video, image and text subsystems in the transmitting device can fragment the video, image or text media type into portions. The size of each portion is corresponding to maximum allowed payload size in a single L2CAP PDU. Each portion of the media type is added to the payload field of L2CAP PDU. Then the LLID of data channel PDU is set to 10 for starting packet and 01 for continuation packet, which contain the remaining portion of the media type.

L2CAP layer in the receiving device can reassemble all portions into a full video, image or text packet and forward the reassembled video, image or text packet to corresponding media module for processing. At step 210, the transferred media type is detected from the reassembled portions of media type. The reassembled media packet is L2CAP SDU.

Figure 3 illustrates a schematic representation of a data packet transmitted over logical link control and adaptation protocol with a particular channel id, according to one embodiment of present invention. In one embodiment of present invention, the base band data packet is of size 52 bytes and the header of the packet contains 5 bytes and the allocated size of the payload is 47 bytes as shown in figure. The link layer 302 decomposition of the data packet shows the payload of base band stage 301 is further decomposed into a preamble 302A having 1 byte, an access code 302B having 4 bytes and payload 302C having 39 bytes and CRC 302D having 3 bytes.
The payload 302C of the link layer is further decomposed in data channel packet data unit 303 layer. According to this layer the data packet contains a header 303A having a size of 2 bytes, a payload 303B of size 33 bytes and MIC of size 4 bytes. Furthermore, at the L2CAP layer 304, the payload 303B and MIC 303Cis further decomposed into payload length 304A having a size of 2 bytes, L2CAPCID 304B having a size of 2 bytes and the payload 304C having a size of 33 bytes.

Figure 4 illustrates a schematic representation of data flow according to Bluetooth low energy protocol.Different layers in the Bluetooth low energy system are baseband layer, link layer and logical link control and adaptation protocol (L2CAP) layer. Further, in one embodiment of present invention, Bluetooth Low Energy system comprises a media subsystem for the transfer of media types.
The baseband 401 defines the packets for BLE advertising and BLE data transmission. .
The link layer 402 is responsible for the creation, modification, release of links required, associated logical transports and the update of parameters related to links between devices. The link layer achieves the above functions by communicating with the link layer in remote Bluetooth devices using the link management protocol (LMP).The LMP allows the creation of new logical links and logical transports between the first device 101 and the second device 102 when required.
The L2CAP layer 403 is expected to carry out resource management operations when submitting L2CAP PDUs to the link layerfor transmitting data to another device. This includes segmentation of L2CAP SDUs into more manageable L2CAP PDUs and setting LLIDs for each L2CAP PDU to indicate start and continuation packets, and to ensure availability for channels with quality of service (QoS) commitments of the device.
The media subsystem 404 generates and consumes media data. According to one embodiment of present invention, the media subsystem includes four subsystems such as audio subsystem, video subsystem, text subsystem and image subsystembased on the type of media to be transmitted.
Media subsystem enables the media processing in uplink and in downlink.Media system in uplink may include media sources such as mike, camera and word processing application. Moreover, the media subsystem may also include encoding modules such as UCS Text encoder, Audio encoder, Image Encoder, Video encoder etc.
Media system in downlink may include media sinks such as speaker and display. Moreover, media subsystem in downlink includes decoding modules such as UCS text decoder, Audio decoder, image decoder, video decoder etc.
Figure 5 illustrates a block diagram of a schematic representation of Bluetooth low energy devices having Bluetooth subsystem and media subsystem.
In one embodiment of present invention, a BLE enabled communication comprises a Bluetooth subsystem and a media subsystem. The Bluetooth subsystem and media subsystem of the first device 101 are represented as Bluetooth subsystem 501A and media subsystem 404A. Likewise, the Bluetooth subsystem and media subsystem of second device 102 arerepresented as Bluetooth subsystem 501B and media subsystem 401B. The media subsystem 501A of first device 101 in view of present invention includes audio subsystem 502A, video subsystem 503A, image subsystem 504A and text subsystem 505A. Likewise, for the second device 102, the media subsystem includes audio subsystem 502B, video subsystem 503B, image subsystem 504B and text subsystem 505B.
In one embodiment of present invention, the fragmented media types such as video, image and text are reassembled at L2CAP layer before sending to corresponding media sub system. However, audio payload in L2CAP PDU is forwarded to audio subsystem without any processing at L2CAP. Audio subsystem is responsible for processing one or multiple audio frames extracted from single L2CAP PDU. The audio, video, image and text subsystems are capable of sending and receiving data concurrently. Likewise, coding and decoding of media type is done by the subsystem concurrently andmedia source and sink runs concurrently.

Although the invention of the method and system has been described in connection with the embodiments of the present invention illustrated in the accompanying drawings, it is not limited thereto. It will be apparent to those skilled in the art that various substitutions, modifications and changes may be made thereto without departing from the scope and spirit of the invention.
,CLAIMS:We Claim:
1. A method of transferring data using Bluetooth low energy comprising:
generating one or more mediapackets having at least one media type as payload;
assigning one or more logical link control and adaptation protocolchannel identification(L2CAP CID)for the generated media packet based on the media type;
transmitting the one or more mediapackets over one or more channels for which the one or more logical link control and adaptation protocolchannel identification (L2CAP CID)are assigned by a first device;
receiving, by a second device, the one or more mediapackets transmitted by the first device; and
detecting the media type transmitted from the first device, based on the L2CAP CID of the one or moremedia packets by the second device.

2. The method as claimed in claim 1, wherein the media type comprises at least one of an audio, video, image and text.

3. The method as claimed in claim 1, where in the media packets are conveyed to L2CAP layer of Bluetooth low energy as L2CAP SDUs in transmitting device.

4. The method as claimed in claim 1, where in media packets are extracted from L2CAP layer as L2CAP SDUs in the receiving device.

5. The method as claimed in claim 1, further comprising:
fragmenting media packets based on maximum size of a logical link control and adaptation protocol packet data unit (L2CAP PDU)and generating at least one L2CAP PDUby the first device before transmitting the media packetto the second device.

6. The method as claimed in claim 1 and 4, further comprising:
reassembling the fragmented media packetsby the second device after receiving the fragmented media packets in at least one L2CAP PDU to generate at least one L2CAP SDU.

7. The method as claimed in claim1, wherein the media type for fragmenting comprises at least one of a video, image, and text.

8. The method as claimed in claim 1, wherein transmitting the one or more mediapackets over one or more L2CAP CIDranging from 0x0007 and 0x003E based on the media type.

9. The method as claimed in claim 6, wherein reassembling the fragmented media type by the second device comprises;
identifying the media type being transmitted from the L2CAP CID assigned to each of the media packet;
segregating one or more media packets based on the media type; and
forwarding one or more segregated media packets to one or more media subsystems based on the media type.

10. The method as claimed in claim 9, wherein the media subsystem comprises at least one of an audio subsystem, video subsystem, image subsystem and text subsystem.

11. A method of transferring data using Bluetooth low energy comprising;
assigning a logical link control and adaptation protocol channel identification (L2CAP CID) to one or more media packet based on media type, wherein the L2CAP CID ranging from 0x0007 and 0x003E;
transmitting the one or more media packet by the first device to a second device using Bluetooth low energy (BLE); and
recognizing the transmitted one or more media packet by the second device based on the L2CAP CID assigned by the first device.

12. A system for transferring data using Bluetooth low energy comprises:
amedia subsystem comprises audio subsystem, image subsystem, video subsystem, and text subsystem, the media subsystem configured for performing one of a:
fragmentingmedia type based on size of the media type and generating at least one logical link control and adaptation protocol packet data unit (L2CAP PDU); and
reassembling the fragmented media type by the second device after receiving the fragmented media type in at least one L2CAP PDU to generate at least one L2CAP SDU; and
a Bluetooth subsystem coupled to the media subsystem configured for performing one of a:
generating one or more data packets having at least one media type as payload and assigningone or more logical link control and adaptation protocol channel identification(L2CAP CID)for the generated mediapacket based on the media type; and
detecting the media type transmitted from the first device, based on the L2CAP CID of the one or more mediapackets by the second device.

Dated this the 04th day of July 2014

Signature

KEERTHI J S
Patent Agent
Agent for the Applicant