Voice communication between a portable communication apparatus and an external terminal

SWEDEN (12) PATENT (13) C2 <11) 522 704 (51)

International class ⁷

H04Q 7/32 (19) SE

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PATENT AND REGISTRATION (45) (41) (22) (24) (62) (86) (86)

Patent filed Application widely available The patent application was submitted on expiration date

Tribal application number

2004-03-02

2002-04-10

2000-10-09

2000-10-09 (21) Patent Application Number 0003645-9

Application received as:

835ΓΙ (83)

International filing day

Filing date for European patent application Deposit of microorganism (30) Priority information Swedish patent application completed international patent application with number □ converted European patent application with number (73) (72) (74) (54) (56)

Assignee

INVENTOR

AGENT

NAME (57)

Telefonaktiebolaget LM Ericsson (publ),

126 25 Stockholm SE

Lars Novak, Lund SE, Tomas Holmström, Dalby SE

Ström &amp; Gulliksson IPC AB

Transmission of audio data and non-audio data between a portable ch communication device and an external terminal CAUTION PUBLICATIONS:

WO Al 9 835 517 (H04Q 7/32), EP Al 0 550 151 (H04B 7/26), US A 5 483 531 (H04B 1/38), US A 5 903 849 (H04M 11/00)

SUMMARY:

A radio communication portable communication apparatus (200) for digital audio data communication (240), representing analog voice signals, with an asynchronous interface (250) for exchanging digital non-audio data (242, 244) with an external terminal (300). The apparatus (200) is adapted to asynchronously exchange the digital audio data (240) with the external terminal (300) over the asynchronous interface (250).

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The numbers in brackets indicate international identification code, INID code. Letters in clamps indicate international document code.

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SUMMARY

A portable communications apparatus (200) for radio grain communication of digital audio data (240), representing analog voice signals, with an asynchronous interface (250) for exchanging digital non-audio data (242, 244) with an external terminal (300). The apparatus (200) is adapted to asynchronously exchange the digital audio data (240) with the external terminal (300) over the asynchronous interface (250).

To be published together with Fig. 2.

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Technical area

The present invention relates generally to portable communication devices of the type capable of communicating voice information or speech between human users. More specifically, the invention relates to a portable communication apparatus with an asynchronous interface for exchanging digital data with an external terminal.

Description of the prior art

Examples of a portable communication device as above are a mobile phone, a cordless telephone, a portable digital pocket calendar, a communicator, a pager, an electronic payment device or a portable navigation device. In the remainder of this document, reference will be made to a mobile phone for any mobile communication network, such as GSM or UMTS. However, the invention is not limited to only one mobile phone. On the contrary, the invention is best defined by the appended independent claims.

Traditionally, older mobile phones could only provide voice communication between two human users via a mobile communications network and, in many situations, a public telephone network. Recently, mobile phones have been provided with additional functionality, such as the ability to provide communication of binary data and / or fax data between the portable communication device and an external terminal. Such an external terminal may be, for example, a desktop personal computer, a portable personal computer or a handheld computer. The external terminal is usually connected to the mobile phone through a wired interface (such as a serial cable connected to a system connector on the mobile phone), an infrared link (such as IrDA) or a

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02021 l CURRENT \ DB \ Public \ DOC \ P \ l 874039s.doc is a radio link for extra short-range data communication (such as Bluetooth® over the 2.4 GHz ISM band).

Binary or fax data is usually transmitted in an asynchronous way between the mobile phone and the external terminal. The nature of binary and fax data makes them suitable for asynchronous transmission; the data to be transmitted can be divided into packets of different lengths, which are then received and reset at the receiving end (either the mobile phone or the external terminal).

Digital speech, on the other hand, is normally transmitted synchronously in a telephone system using, for example, PCM 64 kb / s coding, which includes a continuous bit stream transmission with strict timing requirements. The reason for these strict timing requirements is obvious; Human speech has a real-time character, which does not allow unexpected delays or buffering, which can occur during asynchronous transmission.

Remember that speech traditionally has to be communicated synchronously between a mobile phone and an external terminal, which is difficult to combine with simultaneous transmission of asynchronous binary or fax data. In other words, there may be problems when trying to transfer speech (with preserved timing) between a mobile phone and an external terminal, while at the same time trying to transfer asynchronous binary or fax data to a common multiplexed connection. The reason for this is that voice samples must be sent at exactly the same timing as they are produced. In general, no buffering is allowed. In any case, any buffering must be done with great care as it can introduce unacceptably large delays or delay jets. If a large amount of asynchronous binary or fax data were to be transmitted over the connection, perhaps some voice samples would be delayed to such an extent that the timing between subsequent voice samples would be lost.

WO 98/35517 discloses a portable communication device and an external accessory, between which full-duplex

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02021 CURRENT \ DB \ Public \ DOC \ P \ l874039s.doc so-called asynchronous communication takes place over a synchronous digital interface. A synchronous digital voice signal is multiplexed with an asynchronous data signal to the synchronous interface.

Summary of the Invention

It is an object of the present invention to allow digital speech to be transmitted simultaneously with binary or fax data on the same connection. The invention is more specifically directed at communicating speech over a multiplexed connection together with asynchronous data transmissions between a mobile station and an external terminal, where the voice transmission is efficient in terms of capacity.

The above objectives have been achieved by adapting the mobile station and the external terminal to use an asynchronous transmission protocol, not only for communicating binary data and fax data but also for transmitting voice. Numbers are transmitted asynchronously in encoded form (such as GSM encoded) over the aforementioned asynchronous transmission protocols along with binary and fax data.

More specifically, the objectives have been achieved through a combination of three measures:

Numbers are compressed (encoded), reducing the necessary bandwidth,

Speech is prioritized over binary and fax data. From time to time, if sufficient bandwidth is available, binary data and fax data will be multiplexed by numbers, otherwise only the number will be transmitted.

Flow control is applied with the asynchronous transmission protocol to allow some speech synchronization. In this way, a virtual synchronous voice channel is established over the asynchronous transmission protocol.

The solution for the above purposes is best defined by the appended independent claims. Other objects, features and advantages will emerge from the following de522,704

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Μ narrated the description, from the subclaims as well as from the accompanying drawings.

It should be noted that the term includes / includes when used in this specification is used to indicate the presence of specified features, integers, steps or components but does not exclude the presence or addition of one or more other features, units, steps, components or groups thereof. .

Brief description of the drawings

A preferred embodiment of the present invention will now be described in further detail with reference to the accompanying drawings, in which:

Fig. 1 is a schematic block diagram of a mobile phone operatively connected to a mobile telecommunication network as well as some external accessories which include a personal computer;

Fig. 2 is a block diagram of the mobile phone and the personal computer shown in Fig. 1, and

Fig. 3 is a schematic diagram of a protocol structure for communication of speech, data and fax between the mobile phone and the personal computer in Figures 1 and 2.

Detailed description of the invention

Reference is first made to Fig. 1, which illustrates a portable communication device in the form of an exemplary mobile telephone 1, as well as the environment in which it operates. The mobile phone 1 normally includes a display 2, a keypad 3, a speaker 4 and a microphone

5th Components 2-5 together constitute a user interface through which a user of the mobile phone 1 can interact with and handle the mobile phone. The mobile telephone 1 further comprises a first antenna 6 for establishing a wireless connection 9 to a mobile telecommunication network 11 via a base station 10. Mobile telecommunication network 522 704

02021 lWCURRENT \ DB \ Public \ DOC \ P \ 1874039s.doc So the 11 may be, for example, a Global System for Mobile Communications (GSM) or Universal Mobile Telephone System (UMTS). The mobile phone 1 can also be used to access a global information network 13, via a network port 12, over the wireless link 9. The global information network 13 can be the Internet and the network port 12 can be a WAP server.

The exemplary mobile phone 1 also includes a second antenna 7, which can be used to establish an additional short-range data connection 14 to a first external device 15. The link 14 may be a Bluetooth link, as described in previous sections of this document. For example, the external device 15 may be a printer, a fax machine, a modem, a wireless telephone accessory (such as a headset with a microphone), a computer (e.g., a desktop computer or a laptop computer), but many other devices are also possible.

In addition to the above, the mobile telephone 1 further comprises an IR interface 8 (infrared interface), by means of which the mobile telephone 1 can establish an IR link 19 to a second external device 20, exemplified by a modem in Fig. 1.

A third external device 18 can further be connected to the mobile telephone 1 via a serial cable 17, which is plugged into a system connector 16 in the housing of the mobile telephone 1. The third external device 18 will be referred to as the external terminal for the remainder of this detailed description.

The external terminal 18 is exemplified as a desktop personal computer in Fig. 1. However, it may as well be a portable personal computer, a handheld computer, a portable digital calendar etc. The external terminal 18 can carry out various types of digital communication with the mobile phone 1, such as transmission of binary data and / or electronic fax data between terminal 18 and telephone 1. As will be explained below.

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In the race below, voice information (ie human speech) can also be communicated between terminal 18 and telephone 1. One possible application, among many others, is a situation where a user wants to talk and listen through the external terminal 18's speakers and microphone instead of the corresponding components of the mobile phone. In other words, the external terminal 18 will be used as a kind of hands-free equipment in such an application.

The mobile telephone and the personal computer are given a more detailed illustration in Fig. 2. The mobile station 200 in Fig. 2 corresponds to the mobile telephone 1 in Fig. 1, while the personal computer 300 in Fig. 2 represents the external terminal 18 in Fig. 1.

Mobile station 200 is a GSM TDMA telephone and comprises an antenna 202, a radio block 210, a kanalomkodnings / decoding block 220, a transcoding / decoding block 230, a controller 204, a microphone 236 and a speaker 238. All of these components have a construction thione , which is well known and typical of a TDMA phone available in the market. They are therefore given only a brief description below; its detailed architecture is believed to be well known to those skilled in the art.

The speech coding / decoding block 230 comprises a speech encoder 232 which has an input connected to an output of the microphone 236, and which has an output connected to an input of a channel encoder 222 in block 220. An output of the channel encoder 222 is connected to an input of transmitter 212, which is part of radio block 210. An output of transmitter 212 is connected to antenna 202. Accordingly, the microphone 236 receives in a well-known manner an audible spoken input from a user and converts it into a corresponding electrical signal which is fed to the speech encoder 232. The speech encoder 232 converts the signal into digital form and then applies either HR, FR or EFR. voice transcoding (according to applicable GSM specifications, such as GSM / DCS technology specification 06.10)

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on the signal, and feeds results to the channel encoder 222, which performs channel decoding according to GSM-TDMA standard (according to, for example, GSM / DCS technology specification 05.03). The output of the channel encoder 222 is fed to the transmitter 212, which includes various electronic circuits such as power amplifiers, filters, local oscillators and mixers. Transmitter 212 output is a high frequency TDMA signal in the 900 or 1800 MHz band which is fed to antenna 202 and transmitted in the open air as electromagnetic waves propagating from antenna 202.

Similarly, an incoming TDMA signal is received at the antenna 202 and processed by a receiver 214 in the radio block 210. The function of the receiver 214 is substantially opposite to that of the transmitter 212. An output from the receiver 214 is decoded in a channel decoder 224 in block 220 and further decoded by a speech decoder 234 in block 230. Its output is fed to the speaker 238, which converts the electrical signal into acoustic sound waves to be output to the user.

As will be readily apparent, the controller 204 is responsible for the overall operation and control of the mobile station 200. Controller 204 is advantageously implemented by any commercially available microprocessor or other type of programmable logic circuit.

The mobile station 200 also has a communication unit 250 which provides an asynchronous interface to the personal computer 300 (i.e. the external terminal) over a physical connection 260. The connection 260 is preferably established over a serial cable; however, links other than wire-based are also possible, such as an infrared link (such as IrDA) or an additional shortwave data link (such as Bluetooth).

The communication unit 250 comprises circuit systems for serial communication, such as a UART, a MUX, etc., combined with appropriate control logic and software. The communication unit 250 forms an asynchronous serial communication protocol, rest 5222 704

02021 lWCURRENT \ DB \ Public \ DOC \ P \ 1874039s.doc can be based on the 3G TS 27.010 multiplexer protocol (reference numeral 254 in Fig. 2, 400 in Fig. 3). This protocol is part of the third generation collaboration project (3G PP) and includes a GSM radio data convergence layer 252, 410, which will be explained in further detail with reference to Fig. 3. However, other asynchronous transmission protocols are equally possible, such as the ETSI-GSM protocol 07.10, as long as the functional requirements below are met.

The communication unit 250 provides an asynchronous communication channel, via the physical connection 260, to the personal computer 300, through which binary data 242 and fax data 244 can be communicated. According to the invention, in addition to the above, the communication unit 250 is also adapted to communicate digital audio data 240, which represents GSM-encoded voice signals, via the protocol layers 252 and 254 to the personal computer 300. For example, GSM-encoded digital audio data can be received directly from transmitter 212 in radio block 210 (data field 414 in Fig. 3), put in a data field 412 in GSM radio data convergence layer 410, further included in a data field 405 for 3G TS 27.010 multiplexer protocol 254, 400 and finally, over the physical connection 260 is transmitted to the personal computer 300. Here, the digital data is unpacked through the layers 354/400 and 352/410 in the communication unit 350 of the personal computer 300. Then, the unpacked GSM encoded digital audio data 340 will be forwarded to a GSM speech encoder / decoder 320 which will perform channel and speech decoding corresponding to the above described function of channel encoder 222 in channel decode / decode block 220 decoder decode / decode block 234 in mobile station 23 can be fed to an audio application 310 which will output the voice signal through the personal computer speakers 300 338.

The audio application 310 may further capture a voice signal through a microphone 336 for the personal computer 300 and transmit the voice signal to the GSM speech encoder / decoder 320.

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Ί

Here, GSM-encoded digital audio data 340 will be produced and fed to the communication unit 350 which will put the digital audio data 414 into the convergence layer 352/410 data field 412. The data will in turn be contained in the 27010 multiplex protocol 354/400 data field 405 and transmitted over the physical connection 260 to the communication unit 250 of the mobile station 200. The digital audio data, which originates from the microphone 336 of the personal computer 300, will pass through the protocols 254/400 and 252/410 and will finally be fed as GSM-encoded digital audio data 240 to the transmitter 212 of the mobile station 200 which can transmit the received digital audio data representing speech from a user of the personal computer 300, via the antenna 202 to another mobile telecommunications party.

Accordingly, in the preferred embodiment, it is possible to transmit digital audio data derived from voice signals such as GSM encoded speech through an asynchronous transmission protocol where the GSM encoded voice can be multiplexed with other digital data such as binary data 242/342 / 413 or fax data 244/344/415. This provides at least two important benefits. First of all, because the voice is GSM-encoded, it will require less transmission capacity. Second, since the 3G TS 27.010 multiplexer protocol is already available for asynchronous transmission of, for example, binary and fax data, no additional layer of convergence needs to be implemented for voice transmission. Instead, the GSM-encoded voice will be communicated asynchronously between the mobile station and the external terminal, possibly in a multiplexed manner together with binary data and / or fax data.

The asynchronous transmission protocol referred to above will be described in further detail with reference to Fig. 1. As already mentioned, 3G TS 27.010 multiplexer protocol 400 is capable of communicating binary data (such as radio link protocol data) 413 as well as fax data (such as fax protocol 4 data). a higher data store 420

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02021 lWCURRENT \ DB \ Public \ DOC \ P \ 1874039s.doc so-called 10 through an intermediate GSM radio data convergence layer 410. According to the invention, GSM-encoded voice 414 can also be communicated via 27.010 protocol 400 convergence layer 410 in an asynchronous multiplexed manner together with the binary data 413 and the fax data. 415th

27.010 The frame format of the protocol 400 is illustrated in FIG.

and starts with a frame start field 410 with a length of 1 byte. Then, an address field 402 is provided which is a byte. Address field 402 contains a DLCI value (Data

Link Connection Identifier value), which represents one of 127 different logical channels between the mobile station 200 and the external terminal 300 (Fig. 2). The logical channels for 3G TS 27.010 are given priority, the highest priority is given to channel 0 and the lowest priority is given to channel 126.

GSM-coded voice 414 is transmitted over high priority logic channels, while binary data 413 and fax data 415 can use lower priority logic channels.

Followed by address field 402 is provided a control field 413 having a length of 1 byte. The control field contains 20 standard HDLC control values, which are not referred to in any detail herein. The data length field 404 indicates the length of a subsequent data field 405. The data field carries the actual information to be communicated via protocol 400. Shorter data fields 405 are preferably used to communicate binary data 413 and fax data 415, which allows GSM-encoded voice 414 to be communicated in data field 405 of max in length.

The frame structure of 27.010 protocol 400 continues with a frame receiving control sequence field 406 which is a byte. This field is adapted to store a standard HDLC frame receiving control sequence value, which is calculated either from fields 401, 402 and 403 or on all fields 401405 depending on frame type (as indicated by control field 403). The frame is completed by a frame end field 407, which up 35 takes 1 byte.

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The convergence layer 410 adds a DTX / credit exchange

411 to the data 412 to be transmitted, which may be radio link protocol data 413, fax protocol data 415 or GSM coded voice data 414. Because of this, the radio transmission from mobile station 200 can be controlled so that transmitter 212 becomes free when mobile station 200 has no data to transmit. This functionality is called interrupt transmission (DTX). The information necessary to handle the DTX is carried from the external terminal 300 to the mobile station 200 in a DTX bit, which occupies the most significant bit for the DTX / credit switch 411.

The three least significant bits of DTX / credit switch 411 are used as follows. The mobile station 200 can buffer link radio data frames, and to tell the external terminal 300 how many radio data frames it can accept, the mobile station will provide a credit value to the external terminal 300. The external terminal reduces the credit for each radio data frame transmitted to the mobile station. When the mobile station can transmit radio data frames, it will increase the credit again. The credit value update information is sent together with the data frames

412 from the mobile station 200 to the external terminal 300. The maximum credit value is 7. The credit value can also be used from the mobile station 200 to the external terminal 300 as a kind of flow control. The external terminal 300 may send a credit value of 0 to the mobile station 200, indicating that the mobile station 200 cannot transmit any radio data frames to the external terminal 300 and, consequently, that the radio data must be discarded. Accordingly, in the present invention, the DTX / credit mechanism described above is used to synchronize the transmitter (e.g., the mobile station) and the receiver (e.g., the personal computer) to avoid buffer overflow and loss of speech frames.

The present invention has been described above with reference to some embodiments. Other embodiments 5222 704

02021 However, more than those referred to above are also possible within the scope of the invention, which is best defined by the independent claims appended hereto.

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