IL138760A - Combined data and speech communication in wireless communication networks - Google Patents

Description

138760/3 jvoin1™ mivypn ηυι«τα iQ'ii D'lma na^i yn miwpn Combined data and speech communications in wireless communication networks Celtro Ltd. "ya ηοΊο D016/IL FIELD OF THE INVENTION The present invention generally relates to communication networks, and more particularly to wireless communication networks. l o BACKGROUND OF THE INVENTION The rapid evolution of wireless communication networks, and particularly wireless communication networks for mobile communications such as the Global System for Mobile communications (GSM) network, created a demand for wireless communication of data in addition to wireless communication of speech. Therefore, various standards for data services were developed, such as the General Radio Packet Service (GPRS) standard that allows a subscriber to receive and transmit data in a packet transfer mode. The GPRS standard is described in a publication EN 301 113 6.2.1 (1999-08) of the European Telecommunication 0 Standards Institute (ETSI) entitled "Digital cellular telecommunications system (Phase 2+); General Packet Radio Service (GPRS); Service description; Stage 1", (GSM 02.60 VERSION 6.2.1 Release 1997).

However, transmission of data in addition to speech created a demand for additional bandwidth on air interface, at least in a case where utilization of the 5 bandwidth by speech traffic, that is speech activity, is close to 100%. An increase in bandwidth utilization efficiency is therefore desired and may have substantial economic effects. Since conventional systems, such as systems utilizing GPRS technology, use separation between data and speech at a time slot level, efficient time slot management may achieve some increase of bandwidth utilization 0 efficiency. l An example of time slot management appears in US Patent 4,383,315 to Torng which describes a time division multiplex loop communication system for voice and data with multiaccess time slot seizure and data transmission capability from all station nodes without changing the idle, nonreserved, status of the seized time slot. Although the system of Torng may provide some increase of bandwidth utilization efficiency, such increase is typically limited.

The increase of bandwidth utilization efficiency achieved by the system of Torng is further limited because the system of Torng uses acknowledgment signal packets to acknowledge successful receipt of transmitted bursty data items, such acknowledgement signal packets affecting, particularly in wireless communication networks, delay of received and transmitted signals, complexity and transmission bandwidth. It is therefore appreciated that further improvements are required to provide substantial increase of bandwidth utilization efficiency.

The disclosures of all references mentioned above and throughout the present specification are hereby incorporated herein by reference.

SUMMARY OF THE INVENTION The present invention seeks to provide novel apparatus and improved method for increasing bandwidth utilization efficiency in communication of data in combination with voice in wireless communication networks, and particularly in cellular based wireless telecommunication networks for mobile applications.

In the present invention, communication is analyzed at a frame level. A set of frames including speech frames that is to be transmitted from a transmitting end of a wireless communication network to a receiving end of the wireless communication network is preferably analyzed to determine a subset of the set in which each frame is characterized as at least one of the following: an idle frame; a corrupted frame; a repetitive frame; and a padding frame. Based on frame analysis results, at least part of the data may be transmitted in frames belonging to the subset in time slots originally being allocated as speech time slots within which speech information is to be transmitted. Thus, data may be transmitted, for example, even in time slots in which speech information is transmitted.

It is appreciated that such transmission of data in combination with speech results in reallocation of the original speech time slots as combined data and speech slots. However, such reallocation does not affect actual allocations of speech information in a speech conversation and therefore has no adverse effect on the speech conversation.

There is thus provided in accordance with a preferred embodiment of the present invention a method for transmitting data in combination with speech in a wireless communication network in which information is transmitted in time slots in a frame format, the method including analyzing a set of frames including speech frames that is to be transmitted from a transmitting end of the wireless communication network to a receiving end of the wireless communication network to determine a subset of the set in which each frame is characterized as at least one of the following: an idle frame, a corrupted frame, a repetitive frame, and a padding frame, and transmitting at least part of the data in frames belonging to the subset in time slots originally being allocated as speech time slots within which speech information is to be transmitted. The transmitting preferably includes reallocating the speech time slots as combined data and speech slots.

Preferably, the transmitting end includes a base station (BTS) end, the receiving end includes a mobile terminal (MT) end, and the transmitting includes transmitting the at least part of the data without receiving an acknowledgement of reception of the at least part of the data from the MT end.

The method also preferably includes, prior to the transmitting placing the data in a stand-by queue, and inserting the data in frames belonging to the subset in accordance with the stand-by queue, wherein the transmitting includes transmitting the data in accordance with the stand-by queue. The stand-by queue is preferably determined by a first-in-first-out (FIFO) rule.

The wireless communication network may preferably include a cellular telecommunication network. The cellular telecommunication network preferably includes a Global System for Mobile communications (GSM) network. Preferably, the cellular telecommunication network supports data communication in a packet transfer mode, such as a packet transfer mode defined by the General Packet Radio Service (GPRS) standard.

Preferably, the inserting also includes replacing, in each frame in the subset, bits included in the frame by bits representing the data without changing the size of the frame. Additionally, the inserting includes synchronizing insertion of data in the frames belonging to the subset with a speech conversation.

There is also provided in accordance with a preferred embodiment of the present invention a method for receiving data in combination with speech in a wireless communication network in which information is communicated in a frame format in time slots, the method including receiving, at a receiving end, data and speech transmitted in combination from a transmitting end in time slots that are assigned as combined data and speech slots.

Preferably, the receiving includes detecting existence of data in frames received in the combined data and speech slots by detecting frame control bits indicating existence of data in the frames.

In accordance with a preferred embodiment of the present invention there is also provided a mobile terminal in a wireless communication network in which information is communicated in time slots in a frame format, the mobile terminal including a transmitter operative to transmit data in combination with speech by transmitting the data in frames belonging to a set of frames in which each frame is characterized as at least one of the following: an idle frame, a corrupted frame, a repetitive frame, and a padding frame in time slots originally being allocated as speech time slots within which speech information is to be transmitted, and a receiver operative to receive data in combination with speech in time slots that are assigned as combined data and speech slots.

Additionally, the mobile terminal also includes a detector unit operative to separate frames including speech information received in the combined data and speech slots from frames including data received in the combined data and speech slots. The detector unit is further operative to detect existence of data in frames received in the combined data and speech slots by detecting frame control bits indicating existence of data in the frames.

In accordance with yet another preferred embodiment of the present invention there is also provided a wireless base station (BTS) transceiver (TRX) including a transmitter operative to transmit data in combination with speech to a mobile terminal (MT) by transmitting the data in frames belonging to a set of frames in which each frame is characterized as at least one of the following: an idle frame, a corrupted frame, a repetitive frame, and a padding frame in time slots originally being allocated as speech time slots within which speech information is to be transmitted, and a receiver operative to receive from the MT data in combination with speech in time slots that are assigned as combined data and speech slots.

Further in accordance with a preferred embodiment of the present invention there is also provided a wireless communication network in which data is communicated in combination with speech in time slots that are assigned as combined data and speech slots. Preferably, the data is communicated in a set of frames that is inserted in the combined data and speech slots, the set of frames including frames that are each characterized as at least one of the following: an idle frame, a corrupted frame, a repetitive frame, and a padding frame.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which: Fig. 1 is a simplified block diagram illustration of a preferred implementation of a wireless communication network, the wireless communication network being constructed and operative in accordance with a preferred embodiment of the present invention; Fig. 2 is a simplified block diagram illustration of a preferred implementation of apparatus in the wireless communication network of Fig. 1; Fig. 3 is a simplified block diagram illustration of another preferred implementation of the apparatus of Fig. 2; and Fig. 4 is a simplified flowchart illustration of a preferred method of operation of the apparatus of Figs. 2 and 3 in the wireless communication network of Fig. 1.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Reference is now made to Fig. 1 which is a simplified block diagram illustration of a preferred implementation of a wireless communication network 10, the wireless communication network 10 being constructed and operative in accordance with a preferred embodiment of the present invention.

The wireless communication network 10 may preferably be a digital cellular telecommunication network, such as a Global System for Mobile communications (GSM) network, that provides communication services to a plurality of cell service areas 15. A cell base station (BTS) 20 in each cell service area 15 communicates with a mobile terminal (MT) 25, and preferably with a plurality of MTs 25, via cellular wireless communication. Each cell BTS 20 also preferably communicates with a BTS controller (BSC) 30. It is appreciated that each cell BTS 20 may also communicate with a server 35, for example, via the BTS controller 30.

The BTS controller 30 preferably controls communication between all the BTSs 20 in the communication network 10. It is appreciated that the BTS controller 30 may also operate as a headend for transmitting data to the MTs 25 in the cell service areas 15. Alternatively, the server 35 may transmit data to the MTs 25 via the BTS controller 30. It is appreciated that the server 35 and the BSC 30 may be located at the same location or at separate locations.

Preferably, the wireless communication network 10 employs time division multiple access (TDMA) in which information is transmitted in a plurality of time slots in a frame format. The term "time slot" is used throughout the specification and claims to include a physical channel in a TDMA system. The term "frame" is used throughout the specification and claims to include a packet of information or a block of information including envelope information, such as a packet header or a block header respectively.

Preferably, the wireless communication network 10 supports voice communication as well as data communication in a packet transfer mode.

Reference is now additionally made to Fig. 2 which is a simplified block diagram illustration of a preferred implementation of the BTS controller 30 in communication with one of the MTs 25 in one of the cell service areas 15. It is appreciated that the description below is not limited to a specific MT 25 in a specific cell service area 15. Rather, the description below is applicable to any MT 25 that is located in any one of the cell service areas 15.

Preferably, the BTS controller 30 includes the following elements: a speech encoder-decoder (CODEC) 100; a data buffer and processing unit 105; a frame detector and data inserter/extractor 110; a transceiver (TRX) 115; and a communication port 120. The term "transceiver" is used throughout the specification and claims to include a unit that includes a transmitter and a receiver, preferably, but not necessarily, in a combined device. The frame detector and data inserter/extractor 110 and the data buffer and processing unit 105 may preferably form part of a conventional communication processor or a digital signal processor (DSP). The data buffer and processing unit 105 may preferably receive data from a data service node 122 that may be either separate from the BTS controller 30 or comprised therein.

The MT 25 preferably includes the following elements: a speech CODEC 125; a data buffer and buffer and processing unit 130; a frame detector and data inserter/extractor 135; a TRX 140; and a communication port 145. It is appreciated that the speech CODEC 125, the data buffer and processing unit 130, the frame detector and data inserter/extractor 135, the TRX 140 and the communication port 145 may preferably be similar in functionality to the speech CODEC 100, the data buffer and processing unit 105, the frame detector and data inserter/extractor 110, the TRX 115 and the communication port 120 respectively. Additionally, at least some of the elements of the MT 25 may be also similar in structure to corresponding elements of the BTS controller 30.

The operation of the apparatus of Fig. 2 in the wireless communication network 10 of Fig. 2 is now briefly described. In communication in a downstream direction from the BTS controller 30 to the MT 25, the speech CODEC 100 is preferably operative to convert speech information provided thereto to a set of frames that include speech frames for transmission to the MT 25. The data buffer and processing unit 105 is preferably operative to supply data provided by the data service node 122 to the frame detector and data inserter/extractor 110.

In a preferred embodiment of the present invention the frame detector and data inserter/extractor 110 is operative to analyze the set of frames generated by the CODEC 100 on a frame-by- frame basis to determine a subset of the set in which each frame is characterized as at least one of the following: an idle frame; a corrupted frame; a repetitive frame; and a padding frame. It is appreciated that if a frame has more than one characterization that fits in with the subset, for example a frame that is both a repetitive frame and a corrupted frame, any one of the characterizations may be used in determination of fitness of the frame in the subset.

The term "idle frame" is used throughout the specification and claims to include an unused frame or a redundant frame. The term "corrupted frame" is used throughout the specification and claims to include a frame in which the information is corrupted, or a frame whose envelope is corrupted which typically leads to problems in accessing the frame or routing the frame to a destination.

The term "repetitive frame" is used throughout the specification and claims to include a frame that is a repetition of a previous adjacent frame. The term "padding frame" is used throughout the specification and claims to include a frame created from an inter-frame padding pattern. It is appreciated that padding frames may preferably be defined and generated by the frame detector and data inserter/extractor 110.

Preferably, an idle frame may be recognized according to its header. A corrupted frame may be recognized according to a frame header and/or a conventional control mechanism. A repetitive frame may be recognized by comparison of adjacent frames. Since padding frames are typically generated by the frame detector and data inserter/extractor 110, recognition of padding frames is typically a direct result of their generation.

Based on frame analysis results, the frame detector and data inserter/extractor 110 preferably replaces bits contained in frames belonging to the subset with data bits provided by the data buffer and processing unit 105 thereby generating a set of combinations of speech frames and data frames. It is appreciated that replacement of the bits contained in frames belonging to the subset with the data bits provided by the data buffer and processing unit 105 is preferably performed without changing the size of any of the frames.

Preferably, the replacement of the bits contained in frames belonging to the subset with the data bits contained in the data frames generated by the data buffer and processing unit 105 is performed successively and in accordance with a stand-by queue which also determines a transmission queue of the data. The stand-by queue may preferably be determined by the frame detector and data inserter/extractor 110. It is appreciated that the stand-by queue may be determined, for example, by a first-in-first-out (FIFO) rule. Alternatively, the stand-by queue may be arranged in accordance with levels of importance of the data.

It is further appreciated that replacement of the bits contained in frames belonging to the subset with the data bits provided by the data buffer and processing unit 105 is preferably synchronized with a speech conversation.

Preferably, the set of combinations of speech frames and data frames is provided to the TRX 1 15. The TRX 1 15 is preferably operative to place the speech frames and the data frames in the set of combinations of speech frames and data frames in time slots that are originally allocated as speech time slots within which speech information is to be transmitted. Preferably, placement of the speech frames and the data frames in the set of combinations of speech frames and data frames in the speech time slots is associated with reallocation of the speech time slots as combined data and speech slots. However, it is appreciated that such reallocation does not affect actual allocations of speech information in a speech conversation and therefore has no adverse effect on the speech conversation.

Preferably, the TRX 115 transmits the set of combinations of speech frames and data frames within the combined data and speech slots to the MT 25 via the communication port 120 and the cellular telecommunication network 10. It is appreciated that transmission of the set of combinations of speech frames and data frames to the MT 25 is preferably performed without receiving an acknowledgement of reception of the data from the MT 25. Alternatively, transmission of the data may be performed in response to reception of an acknowledgement of reception of the data from the MT 25.

At the MT 25, the set of combinations of speech frames and data frames is preferably received at the TRX 140 via the communication port 145. The frame detector and data inserter/extractor 135 preferably analyzes the set of combinations of speech frames and data frames received at the TRX 140 on a frame-by-frame basis and separates frames containing speech information from frames containing data information. It is appreciated that the frame detector and data inserter/extractor 135 may detect existence of data in frames belonging to the set by detecting frame control bits indicating existence of data in the frames that contain data information.

Preferably, the frame detector and data inserter/extractor 135 extracts the frames containing data information from the set of combinations of speech frames and data frames and provides the frames containing data information to the data buffer and processing unit 130 which is operative to process the data contained in the frames as is well known in the art and/or to display the data on a display (not shown) in the MT 25 as is well known in the art. The frames containing speech information are preferably provided to the speech CODEC 125 which is preferably operative to process the speech information contained in the speech frames and to provide a voice output to a user of the MT 25 (not shown) as is well known in the art.

Preferably, in communication in a direction upstream from the MT 25 to the BTS controller 30 operation of the MT 25 is similar to the operation of the BTS controller 30 in downstream communication, and operation of the BTS controller 30 is similar to the operation of the MT 25 in downstream communication.

Reference is now additionally made to Fig. 3 which is a simplified block diagram illustration of another preferred implementation of the apparatus of Fig. 2. In Fig. 3, a BTS controller 200 that corresponds to the BTS controller 30 communicates with a MT 205 that corresponds to a MT 25 in one of the cell service areas 15. Communication between the BTS controller 200 and the MT 205 is shown in Fig. 3 only in a direction downstream because operation of the BTS controller 200 and the MT 205 is upstream communication may be similar to the operation of the BTS controller 30 and the MT 25 in upstream communication respectively. Alternatively, the BTS controller 200 and the MT 205 may communicate in the upstream according in accordance with the GPRS standard.

Preferably, data transmitted in the downstream from the BTS controller 200 to the MT 205 is provided according to the GPRS standard. Therefore, the BTS controller 200 and the MT 205 are similar in structure and functionality to the BTS controller 30 and the MT 25 in Fig. 2 except that elements in the BTS controller 200 and the MT 205 that correspond to elements in the BTS controller 30 and the MT 25 operate on data in a GPRS format, and transmission of the data in combination with voice is performed at a plurality of time slots simultaneously, that is at a plurality of channels.

Reference is now made to Fig. 4 which is a simplified flowchart illustration of a preferred method of operation of the apparatus of Figs. 2 and 3 in the wireless communication network of Fig. 1.

Preferably, a set of frames including speech frames that is to be transmitted from a transmitting end of a wireless communication network to a receiving end of the wireless communication network is analyzed at the transmitting end to determine a subset of the set in which each frame is characterized as at least one of the following: an idle frame; a corrupted frame; a repetitive frame; and a padding frame (step 300). Then, data that is to be transmitted to the receiving end is preferably inserted in frames belonging to the subset to replace contents of the frames belonging to the subset (step 310). The data is then transmitted to the receiving end in time slots originally being allocated as speech time slots within which speech information is to be transmitted (step 320).

It is appreciated that various features of the invention that are, for clarity, described in the contexts of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment may also be provided separately or in any suitable sub-combination.

It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described herein above. Rather the scope of the invention is defined by the claims that follow. 138760/2 What is claimed is:

Claims (20)

1. In a wireless communication network in which information is transmitted in time slots in a frame format, a method for communication which comprises transmitting data in combination with speech, the method comprising: analyzing a set of frames including speech frames that is to be transmitted from a transmitting end of the wireless communication network to a receiving end of the wireless communication network to determine a subset of said set in which each frame is characterized as at least one of the following: an idle frame; a corrupted frame; a repetitive frame; and a padding frame; and transmitting at least part of the data in frames belonging to said subset in time slots originally being allocated as speech time slots within which speech information is to be transmitted.

2. A method according to claim 1 and wherein said transmitting comprises reallocating said speech time slots as combined data and speech slots.

3. A method according to claim 1 or claim 2 and wherein said transmitting end comprises a base station (BTS) end, said receiving end comprises a mobile terminal (MT) end, and said transmitting comprises transmitting said at least part of the data without receiving an acknowledgement of reception of said at least part of the data from the MT end.

4. A method according to any of claims 1 - 3 and also comprising, prior to said transmitting: placing said data in a stand-by queue; and inserting said data in frames belonging to said subset in accordance with said stand-by queue, wherein said transmitting comprises transmitting said data in accordance with said stand-by queue.

5. A method according to claim 4 and wherein said stand-by queue is determined by a first-in-first-out (FIFO) rule.

6. A method according to any of claims 1 - 5 and wherein the wireless communication network comprises a cellular telecommunication network.

7. A method according to claim 6 and wherein said cellular telecommunication network comprises a Global System for Mobile communications (GSM) network.

8. A method according to claim 6 or claim 7 and wherein said cellular telecommunication network supports data communication in a packet transfer mode.

9. A method according to claim 6 or claim 7 and wherein said cellular telecommunication network supports data communication in a packet transfer mode defined by the General Packet Radio Service (GPRS) standard.

10. A method according to claim 4 and wherein said inserting also comprises: replacing, in each frame in said subset, bits comprised in the frame by bits representing the data without changing the size of the frame.

11. A method according to claim 4 or claim 10 and wherein said inserting comprises synchronizing insertion of data in said frames belonging to said subset with a speech conversation.

12. A method according to claim 1 , further comprising: receiving, at a receiving end, data and speech transmitted in combination from a transmitting end in time slots that are assigned as combined data and speech slots; and detecting existence of data in frames received in said combined data and speech slots by detecting frame control bits indicating existence of data in said frames.

13. A mobile terminal in a wireless communication network in which information is communicated in time slots in a frame format, the mobile terminal comprising: a transmitter operative to transmit data in combination with speech by transmitting the data in frames belonging to a set of frames in which each frame is characterized as at least one of the following: an idle frame; a corrupted frame; a repetitive frame; and a padding frame in time slots originally being allocated as speech time slots within which speech information is to be transmitted; and a receiver operative to receive data in combination with speech in time slots that are assigned as combined data and speech slots.

14. A mobile terminal according to claim 13 and also comprising a detector unit operative to separate frames comprising speech information received in said combined data and speech slots from frames comprising data received in said combined data and speech slots. 138760/4

15. A mobile terminal according to claim 14 and wherein said detector unit is operative to detect existence of data in frames received in said combined data and speech slots by detecting frame control bits indicating existence of data in said frames.

16. A wireless base station (BTS) transceiver (TRX) comprising: a transmitter operative to transmit data in combination with speech to a mobile terminal (MT) of claim 13, by transmitting the data in frames belonging to a set of frames in which each frame is characterized as at least one of the following: an idle frame; a corrupted frame; a repetitive frame; and a padding frame in time slots originally being allocated as speech time slots within which speech information is to be transmitted; and a receiver operative to receive from said MT data in combination with speech in time slots that are assigned as combined data and speech slots.

17. A wireless communication network in which data is communicated in combination with speech in time slots that are assigned as combined data and speech slots and wherein the data is communicated in a set of frames that is inserted in said combined data and speech slots, said set of frames including frames that are each characterized as at least one of the following: an idle frame; a corrupted frame; a repetitive frame; and a padding frame.

18. A method according to any of claims 1 - 12 and substantially as described herein above.

19. A method according to any of claims 1 - 12 and substantially as shown in the drawings.

20. A mobile terminal according to any of claims 13 - 15 and substantially as described herein above.