KR20010103732A - Data transmission method between base station and mobile swtiching center - Google Patents

Abstract

The present invention provides a system and method for merging packet data, voice, and fax / modem communications within the same communication protocol. According to exemplary embodiments of the present invention, the unused mode code values of a conventional TTL frame are adjusted to integrate packet data together with voice and fax / modem in one TTL frame. Thus, communication resources are used more efficiently.

Description

TECHNICAL FIELD [0001] The present invention relates to a method of transmitting data between a base station and a mobile switching center,

As the communication system grows commercially, and especially as cellular wireless telephone systems grow explosively, system designers have sought ways to increase system capacity without compromising customer quality beyond acceptable limits. At the same time, mobile communication devices for transmitting data other than voice have become very popular among customers. As a required service in a wireless communication system, the possibility of using a web browser to send and receive e-mail and access the World Wide Web has often been discussed. In response, communication system designers are looking for ways to efficiently transmit data information to or from mobile users.

There are fundamental differences between the requirements of data communication and voice communication for example. For example, the delay requirement is higher for voice, which is a real-time service, and the error requirement is higher for data communication with lower delay constraints. Cellular communication systems have begun to use packet data protocols that are more suitable for data transmission than circuit-switched protocols. In order to handle frequent traffic or burst traffic of small volumes of data such as those associated with Internet browsing, packet-switched networks that provide mobile packet data services are preferred, such as GPRS (General Packet Radio Service), Cellular Digital Packet Data) and PDC (Personal Digital Cellular). Unlike circuit switched data services, mobile packet data services do not need to use dedicated wireless resources. For example, under the GPRS standard, each packet of data includes a routing address that provides a quick setup and allows multiple users to share wireless resources.

Packet service integration in both GSM (Global System for Mobile communication) cellular systems as well as D-AMPS (Digital Advanced Mobile Phone System) cellular systems is currently being standardized. Currently, GSM systems provide circuit switched data services, which can be used to interconnect with external data networks. Circuit-switched data services are used not only for packet-switched data communications, but also for circuit-switched data communications. In order to make packet-switched data communication more efficient, a new packet-switched data service called General Packet Radio Services (GPRS) has been introduced as part of GSM. Since GPRS is a GSM service, parts of the GSM base system are used. Parts of such a GSM communication system are described in the European Telecommunication Standard Institute (ETSI) document ETS 300 574, which is incorporated herein by reference.

GPRS allows packet-switched communication and supports both connectionless protocols (e.g., IP) as well as connection-oriented protocols (e.g., X.25). All channels are configured for circuit switched or packet switched traffic. One of the advantages of the packet switched data communication protocol is that a single transmission resource can be shared among a plurality of users. Thus, for example, in the case of a GSM cellular system, a timeslot of a radio frequency carrier may be used by some mobile users for data transmission and reception. Shared transmission resources are managed by the network side of the cellular system for both downlink and uplink transmissions.

Figure 1 illustrates an example radio frequency band that supports both circuit switched and packet switched traffic of a GPRS system. As shown in FIG. 1, an example radio frequency band is divided into eight time slots. A timeslot may support a single voice call, a single fax / modem call, or one or more packet data users. For example, timeslot 1 is assigned to voice call 1 and timeslot 2 is shared by GPRS users 1-3.

GPRS is very flexible to allow integration of voice and packet data traffic over a single carrier. However, it requires significantly more bandwidth than other packet data systems. GPRS requires 25 KHz per time slot, whereas other systems (e.g., CDPD) require 10 KHz per time slot.

The CDPD system and the PDC system, which are part of the D-AMPS, describe different methods from those described above for packet data communication. In a CDPD system, certain base stations are dedicated for packet data transmission. Thus, voice and packet data traffic is not mixed. In a PDC system, a base station includes separate transceivers for packet data communication. For CDPD systems, voice and packet data traffic is not mixed.

Conventional methods for providing packet data have failed to efficiently integrate packet data, voice, and fax / modem traffic. In an attempt to provide both packet data and voice communications, conventional systems have used dedicated base stations, transceivers and channels exclusively for packet data transmission. As a result, communication resources have been inefficiently used. Also, because of the high cost of the transport channel, conventional methods have resulted in costly inefficient systems.

Thus, there is a need for a system that integrates voice, fax / modem and packet data communications in a cost-effective manner.

<Summary>

The present invention overcomes the disadvantages described above by providing a system and method for merging packet data, voice, and fax / modem communications within the same communication protocol. According to an exemplary embodiment of the present invention, the unused mode code values of the conventional TTL frame are adjusted to integrate the packet data with the voice and fax / modem of the TTL frame. As a result, communication resources are used more efficiently.

The present invention relates generally to wireless communication systems and, more particularly, to systems and methods for integrating voice, fax / modem and packet data in a cost-effective manner.

BRIEF DESCRIPTION OF THE DRAWINGS The above objects and features of the present invention will become apparent from the following description of the preferred embodiments with reference to the accompanying drawings.

Figure 1 illustrates an example radio frequency band that supports both circuit switched and packet switched traffic in a GPRS system.

2 illustrates a conventional PDC wireless communication system.

FIG. 3 illustrates the base station 210 and MSC 220 of FIG. 2 in more detail.

Figure 4 illustrates a conventional TTL frame that may include voice and / or fax / modem information or packet data information.

5 illustrates a base station and MSC according to exemplary embodiments of the present invention.

In the following description, specific circuits, circuit components, methods, and the like have been described in detail to facilitate understanding of the present invention, which is for illustrative purposes only, and is not limited thereto. It will be understood by those skilled in the art that the present invention may be applied to other embodiments that depart from the specific details. In other instances, detailed descriptions of well-known methods, devices, and circuits are omitted so as not to obscure the description of the present invention.

Exemplary wireless communication systems described herein are described as using a TRA-TRX link (TTL) protocol in which communication between a base station and a mobile switching center is performed via a TTL frame. However, those skilled in the art will recognize that the concepts described herein may be equally applied to other protocols. As such, some exemplary embodiments provide examples relating to a PDC system, but the methods described herein are equally applicable to wireless base stations in any system.

2 illustrates a conventional PDC wireless communication system. 2, the conventional system has a number of mobile stations _{(MS; 200 1 -200 N)} , a base station (BS; 210), the mobile services switching center (MSC; 220), the packet associated with the mobile packet network 250 such as the Internet A service switching center (PMSC) 230, and a public switched telephone network (PSTN) 240. When operating, a number of mobile stations 200 ₁ -200 _N communicate with base station 210 in a well known manner. Each of the mobile stations 200 ₁ -200 _N may transmit voice, fax / modem data and / or packet data. Base station 210 receives information from mobile stations via transceivers, processes the information, and dispatches processed information to MSC 220. [ Those skilled in the art will appreciate that base station 210 also receives information from MSC 220 and transmits the information to one or more mobile stations. In accordance with conventional systems, the base station includes separate transceivers for voice and fax / modem communications and packet data communications.

In the MSC 220, information from the base station 210 is sent to the PSTN 24 when the information is voice or fax / modem data, and to the packet data network 22 via the PMSC 230 when the information is packet data. (To 250). Those skilled in the art will appreciate that the network shown in Figure 2 typically includes other components such as routers (not shown) that assist in the reception, processing and transmission of information in the network. Are provided for convenience only. Wireless communication systems generally include multiple base stations, MSCs, PMSCs, and the like.

FIG. 3 illustrates the base station 210 and MSC 220 of FIG. 2 in more detail. In Figure 3, the base station 210 has antennas 215 and 216 two transceiver that receives information from the mobile stations (200 ₁ -200 _N) which each transmits information to mobile stations (200 ₁ -200 _N) The TRX 212, and the TRX 213. [ One of the transceivers, for example, the TRX 212, processes only packet data communications, and the other transceiver, TRX 213, handles communications, including voice and fax / modem transmissions. The base station 210 also includes a control unit (CU) 214 for controlling information routing via a wire line 250 connecting the base station 210 and the MSC 220.

The MSC 220 includes a transcoder and rate adapter board (TRAB) 222 that processes information received at the MSC 220 in a well known manner. The TRAB 222 is associated with the transceiver 213. Eventually, the TRAB 222 processes voice and fax / modem information and sends and receives information from the PSTN 240. On the other hand, TRX 212 is not associated with TRAB. Thus, the TRX 212 is directly connected to the PMSC 230 directly. The MSC 220 also includes exchange terminal circuits 221, 224, and 225 that operate as switches for transmitting data to the appropriate destination. Those skilled in the art will recognize that typical base stations and MSCs generally include more components to assist in receiving, transmitting and processing information than the components shown in FIG.

As described above, base station 210 includes a transceiver for voice and fax / modem communications, a TRX 213, and a transceiver, TRX 212, for packet data communication. Transceivers 212 and 213 communicate with the MSC via wire line 250. Communication between the TRX 213 and the TRAB 222 is performed using the TTL protocol. The TTL protocol is a document entitled " TRA-TRX with Signaling Technology, IMUX / HR (Signal Description, TRA-TRX with IMUX / HR) ", 10/15 14-ANT 244 02, Rev. A, which document is incorporated herein by reference and is appended as Appendix A. On the other hand, communication between the TRX 212 and the PMSC 230 is performed using another protocol (hereinafter referred to as " conventional packet data protocol "). This protocol requires separate channels on wire line 250.

Figure 4 illustrates a conventional TTL frame that may include voice and / or fax / modem information. In FIG. 4, a conventional TTL frame includes, among other things, a header field including synchronization information, two sub-frames and a tail frame. Each sub-frame contains three TTL-individuals (TTL-individuals) and an extension field. The term " TTL-individual interval " is used to designate a TTL resource assigned to a particular TRX and TRAB pair. Each TTL-individual interval includes a data field and a control field. Each data field of a particular frame includes voice and / or fax / modem information as described above. Each control field of the TTL-individual section includes the following subfields: A quality information sub-field, a dummy data display sub-field, a mode code sub-field, and a cyclic redundancy check (CRC) sub-field.

Conventionally, mode code sub-fields have been used in the TTL protocol to identify / differentiate services of different types and rates. The coding of conventional mode code sub-fields is provided in Table 1 below. As shown, the conventional TTL protocol does not use mode code values (8-14). As a result, these values can be used to apply the TTL protocol for future services.

Code value code Code Usage 0 0000 Not used One 0001 Spare code 2 0010 A-S / FR mode 3 0011 A-S / HR mode 4 0100 T-C / FR mode 5 0101 Reserved for "T-C / HR mode" 6 0110 N-S / FR mode 7 0111 Reserved for "N-S / HR mode" 8 1000 Spare code 9 1001 Spare code 10 1010 Spare code 11 1011 Spare code 12 1100 Spare code 13 1101 Spare code 14 1110 Spare code 15 1111 IDLE mode

In Table 1, "AS / FR" represents an active-speech full rate mode, "AS / HR" represents an active-speech half rate mode, "TC / FR" represents Through-Connect full rate mode, "TC / HR" represents Through-Connect half rate mode, "NS / FR" Quot; indicates a non-speech full rate mode, and " NS / HR " indicates a non-speech half rate mode.

As discussed above, the conventional TTL protocol does not provide the capability to integrate voice and packet data information in a single TTL frame. Thus, TTL frames are dedicated to voice and / or fax / modem information, thereby allowing transceivers operating with TRABs to be dedicated to voice and / or fax / modem information only. Those skilled in the art will appreciate that due to this constraint, there are instances where conventional frames are transmitted with unassigned TTL individual intervals, wasting useful communication resources. For example, suppose that voice information occupying data fields of four TTL individual intervals and packet data having an information bandwidth matching the data fields of two TTL individual intervals are transmitted from the base station to the MSC. Using the conventional TTL protocol, the TTL individual intervals 2, 5 may be left unassigned and the voice information may be transmitted in TTL individual intervals (0, 1, 3, 4) of the TTL frame. Although the packet data can occupy TTL individual intervals (2, 5) by being transmitted in the data fields of two TTL individual intervals, the conventional TTL protocol rejects the packet data transmission, so that the packet data can be transmitted to individual MSC- To be transmitted through a conventional packet data protocol.

Thus, conventional attempts to provide packet data communications in a wireless communication environment have resulted in specific base stations, transceivers, or channels dedicated to the communication. These conventional methods use communications resources inefficiently. The present invention provides a method and system for integrating voice and fax / modem communications and packet data communications in a cost-effective manner.

5 illustrates a base station 310 and an MSC 320 in accordance with one exemplary embodiment of the present invention. As shown, base station 310 includes two transceivers, TRX 312 and TRX 313, which communicate with one or more mobile stations via respective antennas 315 and 316. In accordance with the present invention, both transceivers 312 and 313 can handle both packet data, voice, and fax / modem communications. Similar to the system shown in Figure 3, a control unit (CU) 314 controls the transmission of information over a wire line 250 that connects the base station 310 and the MSC 320.

Exemplary MSC 320 includes two transcoder and rate adapter boards, TRAB 322 and TRAB 323. According to the present embodiment, both TRAB 322 and TRAB 323 can process packet data, voice, and fax / modem information. Each TRAB is coupled to both the PMSC 230 and the PSTN 240. For voice and / or fax / modem transmissions, as described above, TRABs process information in a well known manner. On the other hand, in the case of packet data transmission, the TRAB simply routes the data to the intended destination. Conventional TRABs can be modified to perform the functions described above by reprogramming the software.

Similar to conventional systems, base station 310 and MSC 320 communicate using the TTL protocol. However, in accordance with the present invention, the TTL protocol allows packet data, voice, and fax / modem communications to be consolidated within a single TTL frame. The present invention uses the unused mode code values (8-13) of the TTL-individual interval control field to indicate packet data information. Table 2 shows the new mode codes for the values of the TTL protocol (8-13).

Code value code Code Usage 8 1000 Indicates that the packet data does not start or end in this TTL-individual section. 9 1001 Indicates that the packet data starts in this TTL-individual section. 10 1010 Indicates that the packet data ends in this TTL-individual interval (the eight least significant bits of this TTL-individual interval contain a pointer to the end of the message). 11 1011 Packet data begins and ends in this TTL-individual interval (the eight least significant bits of this TTL-individual interval contain a pointer to the end of the message). 12 1100 Indicates the end of one packet data message and the beginning of another packet data message. 13 1101 Indicates the beginning of another packet data message following the beginning and end of one packet data message.

Those skilled in the art will appreciate that the mode codes described above are merely exemplary and that the mode codes can be adjusted in other ways to meet particular network requirements.

The following example illustrates the advantages of the present invention. Assume once again that the base station desires to transmit to the MSC the voice information occupying the data fields of the four TTL individual intervals and the packet data having the information bandwidth suitable for the data fields of the two TTL individual intervals. According to conventional methods, voice information and packet data must be transmitted on separate MSC-BS channels. That is, one TRAB-TRX pair is needed for voice transmission and another TRX is needed for packet data transmission. However, in accordance with the present invention, a single TRX-TRAB pair and a single SMC-BS channel can be used to transmit both voice information and packet data. In addition, packet data can be transmitted with voice and / or fax / modem information in one TTL frame by changing the TTL protocol. As a result, useful communication resources are used more efficiently.

The systems and methods described above for integrating packet data, voice and fax / modem communications within a single TTL frame are both easy to implement and cost effective. Such packet data / voice / fax / modem integration procedures can be implemented through software programming without the need to replace hardware components. By integrating packet data, voice, and fax / modem communications within a single TTL frame, the present invention uses information bandwidth more efficiently. Further, the present invention is configured to handle packet data, voice, and fax / modem communications with a single transceiver, thereby eliminating the need for dedicated transceivers. As a result, the present invention efficiently uses communication resources.

The principles, preferred embodiments and modes of operation of the present invention have been described above. However, the present invention is not limited to the specific embodiments described above. Accordingly, the above-described embodiments are to be considered illustrative and not restrictive, and those skilled in the art will readily appreciate that the embodiments may be practiced by persons skilled in the art without departing from the principles of the invention as defined in the following claims It should be noted that this may change.

Claims (18)

A method for transmitting both data and non-data information between a base station and a mobile service switching center using a communication protocol, And transmitting both the data and the non-data information in a single frame of the communication protocol. The method according to claim 1, And the non-data information is audio information. The method according to claim 1, And the non-data information is fax / modem information. The method according to claim 1, Wherein the communication protocol is a TTL protocol. 5. The method of claim 4, Characterized in that the single frame comprises a plurality of individual sections and at least one of the individual sections carries the data and at least one of the individual sections carries the non-data information. How to. 6. The method of claim 5, Wherein the individual section includes a plurality of sub-fields, at least one of the sub-fields identifying that the individual section carries data or non-data information. In the system, Means for transmitting data and non-data information within a single frame of a communication protocol; Means for receiving the single frame and routing the data to a first routing line and routing the non-data information to a second routing line &Lt; / RTI &gt; 8. The method of claim 7, And the non-data information is audio information. 8. The method of claim 7, And the non-data information is fax / modem information. 8. The method of claim 7, Wherein the non-data information is both voice and fax / modem information. 8. The method of claim 7, Wherein the communication protocol is a TTL protocol. 12. The method of claim 11, Wherein the single frame comprises a plurality of individual intervals, at least one of the individual intervals carrying the data and at least one of the individual intervals carrying the non-data information. 13. The method of claim 12, Wherein each individual section includes a plurality of sub-fields, wherein at least one of the sub-fields identifies that the individual section carries data or non-data information. 8. The method of claim 7, Characterized in that the first routing line is a packet data network and the second routing line is a telephone network. In the base station, At least one transceiver for processing data and non-data information according to a communication protocol and for routing the data and non-data information, Data and non-data information is routed by the at least one transceiver within a single frame of the communication protocol . 16. The method of claim 15, Wherein the communication protocol is a TTL protocol. 17. The method of claim 16, Wherein the single frame comprises a plurality of individual intervals, at least one of the individual intervals carrying the data and at least one of the individual intervals carrying the non-data information. 18. The method of claim 17, Wherein each individual section includes a plurality of sub-fields, wherein at least one of the sub-fields identifies that the individual section carries data or non-data information.