WO2009045754A2

WO2009045754A2 - Method for transmitting color ring back tones

Info

Publication number: WO2009045754A2
Application number: PCT/US2008/076987
Authority: WO
Inventors: Chao Jiang; Jian-Hua Hou
Original assignee: Motorola, Inc.
Priority date: 2007-09-29
Filing date: 2008-09-19
Publication date: 2009-04-09
Also published as: WO2009045754A3; CN101400034A

Abstract

A method for instructing a mobile switching center to initiate a transmission of a color ring back tone in a mobile communications network is useful for increasing a rate of successful transmissions of color ring back tones, and for increasing overall network efficiency. The method includes processing, at a home location register, first data describing a color ring back tone capability of a first mobile switching center (step 305). Second data describing a color ring back tone capability of a second mobile switching center is then processed at the home location register (step 310). It is then determined that the first mobile switching center is a preferred mobile switching center for initiating a transmission of a color ring back tone based on the first data and the second data (step 315). The first mobile switching center is therefore instructed to initiate the transmission of the color ring back tone (step 320).

Description

METHOD FOR TRANSMITTING COLOR RING BACK TONES

Field of the Invention

The present invention relates generally to playing ring back tones in mobile communications networks, and in particular to instructing mobile switching centers to initiate transmission of color ring back tones.

Background

Ring back tones were originally defined as telephone call signaling components that were heard by a calling party after a dialing sequence was completed by the calling party but before a call was answered by a called party. Conventional ring back tones are often different in various countries. In the United States, a conventional ring back tone comprises a 440 Hz tone summed with a 480 Hz tone that is alternately switched on for two seconds and then switched off for four seconds. A beat phenomenon created by the two summed tones results in the called party hearing a ringing sound.

More recently, personalized ring back tones, also known as color ring back tones, have been developed. A color ring back tone replaces a conventional ring back tone with a personalized audio, visual or multimedia presentation that is defined by a user of a called telephone or other electronic communication device. Thus, for example, a wireless service subscriber is able to select a music segment, sound, jingle, phrase, message or multimedia file that is delivered to callers that dial a phone number of the subscriber. Similar to conventional ring back tones, color ring back tones are provided to a calling party after a dialing sequence has been completed but before a call is answered by a called party.

However, when a called telephone roams from its home network to a visiting network, network protocols and resources may prevent a color ring back tone associated with the called telephone from being played at a calling telephone. Such a failure to play a color ring back tone may result even when a calling telephone is located in a home network of a roaming called telephone. Brief Description of the Figures

In order that the invention may be readily understood and put into practical effect, reference will now be made to exemplary embodiments as illustrated with reference to the accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views. The figures together with a detailed description below, are incorporated in and form part of the specification, and serve to further illustrate the embodiments and explain various principles and advantages, in accordance with the present invention where: FIG. 1 is a message sequence chart illustrating a method for instructing a caller visiting/gateway mobile switching center (V/GMSC) to initiate a transmission of a color ring back tone in a mobile communications network, according to some embodiments of the present invention;

FIG. 2 is a message sequence chart illustrating a method for instructing a callee VMSC to initiate a transmission of a color ring back tone in the mobile communications network, according to some embodiments of the present invention;

FIG. 3 is a general flow diagram illustrating a method for instructing a mobile switching center to initiate a transmission of a color ring back tone in a mobile communications network, according to some embodiments of the present invention; and

FIG. 4 is a block diagram illustrating system components of a callee home location register, according to some embodiments of the present invention.

Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention. Detailed Description

Before describing in detail embodiments that are in accordance with the present invention, it should be observed that the embodiments reside primarily in combinations of method steps and device components related to instructing a mobile switching center to initiate a transmission of a color ring back tone in a mobile communications network. Accordingly, the device components and method steps have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

In this document, relational terms such as first and second, top and bottom, front and back, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or device that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or device. An element preceded by "comprises a..." does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

According to one aspect, the present invention comprises a method for instructing a mobile switching center (MSC) to initiate a transmission of a color ring back tone (CRBT) in a mobile communications network. The method includes processing, at a home location register (HLR), first data describing a CRBT capability of a first MSC. Next, at the HLR, second data describing a CRBT capability of a second MSC are processed. It is then determined that the first MSC is a preferred MSC for initiating a transmission of a CRBT based on the first data and the second data. The first MSC is then instructed to initiate the transmission of the CRBT. Thus, according to some embodiments of the present invention, both an originating MSC and a terminating MSC communicate to a callee HLR their respective CRBT capabilities. As described in detail below, such communications can be made using various types of network signaling and call setup messages. Then, when a call is placed to a mobile telephone that is managed by the HLR, the HLR can determine, based on the CRBT capabilities of the originating and terminating MSCs, a preferred MSC for initiating a transmission of a CRBT. That enables a CRBT to be successfully played at a caller telephone, even if a callee telephone has roamed outside of its home network and is no longer capable of initiating a CRBT. Further, the HLR can consider other network parameters, such as network loading parameters, when determining a preferred MSC for initiating transmission of a CRBT. That can decrease unnecessary network signaling traffic and thus increase overall network efficiency.

Referring to FIG. 1, a message sequence chart illustrates a method for instructing a caller visiting/gateway mobile switching center (V/GMSC) 105 to initiate a transmission of a color ring back tone in a mobile communications network 100, according to some embodiments of the present invention. Consider that the caller V/GMSC 105 is operating in a network 200 and receives a send routing information (SRI) message 110 from a caller telephone (not shown). The SRI message 110 is then forwarded from the caller V/GMSC 105 to a callee home location register (HLR) 115 in the network 100. The SRI message 110 includes data that describe a color ring back tone capability of the caller V/GMSC 105.

At block 120 the callee HLR 115 then determines a preferred mobile switching center (MSC) for initiating a transmission of a color ring back tone to the caller telephone. For example, the callee HLR 115 compares data that describes a color ring back tone capability of the caller V/GMSC 105 with data that describe a color ring back tone capability of a callee visiting mobile switching center (VMSC) 125 located in the network 100. Also, the callee HLR 115 may consider parameters of the network 100 and parameters of the network 200, such as network loading parameters of inter-public land mobile network signaling. If the callee HLR 115 determines that the caller V/GMSC 105 is a preferred MSC for initiating a color ring back tone to the caller telephone, the callee HLR 115 then transmits a conventional provide routing number (PRN) message 130 to the callee VMSC 125. The callee VMSC 125 then responds with a provide roaming number acknowledgement (PRN Ack) message 135. The callee HLR 115 next sends a send routing information acknowledgement

(SRI Ack) message 140 to the caller V/GMSC 105. The SRI Ack message 140 instructs the caller V/GMSC 105 to initiate transmission of a color ring back tone to the caller telephone. The SRI Ack message also includes a real Mobile Station Roaming Number (MSRN) assigned to a callee mobile station/user equipment (MS/UE) 155, such as a callee's mobile telephone. The MSRN is an E.164 defined telephone number used to route telephone calls in the networks 100, 200. E.164 is an International Telecommunication Union Telecommunication Standardization Sector (ITU-T) recommendation which defines an international public telecommunication numbering plan. An initial address message (IAM) 145 is then transmitted from the caller V/GMSC 105 to the callee VMSC 125 and, in response, a call setup message 150 is transmitted from the callee VMSC 125 to the callee MS/UE 155. If the callee MS/UE 155 is switched on and is accepting calls, the callee MS/UE 155 then transmits an alerting message 160 back to the callee VMSC 125. In response, the callee VMSC 125 transmits an address complete message (ACM) 165 to the caller V/GMSC 105, which is forwarded to the caller telephone.

Because the caller V/GMSC 105 was instructed by the SRI Ack message 140 to initiate the transmission of the color ring back tone, the caller V/GMSC 105 next transmits an IAM message 170 to a callee color ring back tone server (CRBT S VR) 175. The callee CRBT_SVR 175 then transmits an ACM message 177 and an answer message (ANM) 180 to the caller V/GMSC 105. The ACM message 177 indicates that all information required to identify the callee MS/UE 155 has been received by the callee CRB T S VR 175. Next, at block 183, the callee CRBT S VR 175 transmits a color ring back tone to the caller V/GMSC 105, which color ring back tone is then played at a caller telephone. For example, the color ring back tone can be a personalized audio, visual or multimedia presentation that is predefined by a user of the callee MS/UE 155. When the call is answered at the callee MS/UE 155, a connect message 185 is transmitted from the callee MS/UE 155 to the callee VMSC 125, which in turns transmits an answer message 188 to the caller V/GMSC 105. At block 190, the callee VMSC 125 then connects the call between the caller telephone with the callee MS/UE 155, and bypasses a CRBT path through the callee CRBT SVR 175. Finally, when the call is completed, the caller V/GMSC 105 transmits a release message 193 to the callee CRBT-SVR 175, and the CRBT-SVR 175 responds by sending a release communication (ReI Com) message 195 back to the caller V/GMSC 105.

Referring to FIG. 2, a message sequence chart illustrates a method for instructing the callee VMSC 125 to initiate a transmission of a color ring back tone in the mobile communications network 100, according to some embodiments of the present invention. Consider that the caller visiting/gateway mobile switching center (V/GMSC) 105 is operating in the network 200 and receives a send routing information (SRI) message 210 from a caller telephone (not shown). The SRI message 210 is then forwarded from the caller V/GMSC 105 to the callee home location register (HLR) 115 in the network 100. The SRI message 210 includes data that describe a color ring back tone capability of the caller V/GMSC 105.

At block 220 the callee HLR 115 then determines a preferred mobile switching center (MSC) for initiating a transmission of a color ring back tone to the caller telephone. For example, the callee HLR 115 compares data that describes a color ring back tone capability of the caller V/GMSC 105 with data that describe a color ring back tone capability of the callee visiting mobile switching center (VMSC) 125 located in the network 100. If the callee HLR 115 determines that the callee VMSC 125 is a preferred MSC for initiating a color ring back tone to the caller telephone, the callee HLR 115 then transmits a provide routing number (PRN) message 230 to the callee VMSC 125, where the PRN message 230 instructs the callee VMSC 125 to initiate transmission of a color ring back tone to the caller telephone. The callee VMSC 125 then responds with a provide roaming number acknowledgement (PRN Ack) message 235. The callee HLR 115 next sends a conventional send routing information acknowledgement (SRI Ack) message 240 to the caller V/GMSC 105, including a real MSRN of the callee MS/UE 155. An initial address message (IAM) 245 is then transmitted from the caller V/GMSC 105 to the callee VMSC 125 and, in response, a call setup message 250 is transmitted from the callee VMSC 125 to a callee mobile station/user equipment (MS/UE) 155 such as a callee's mobile telephone. If the callee MS/UE 155 is switched on and is accepting calls, the callee MS/UE 155 then transmits an alerting message 260 back to the callee VMSC 125. In response, the callee VMSC 125 transmits an address complete message (ACM) 265 to the caller V/GMSC 105, which is forwarded to the caller telephone.

Because the callee VMSC 125 was instructed by the PRN message 230 to initiate the transmission of the color ring back tone, the callee VMSC 125 next transmits an IAM message 270 to the callee color ring back tone server (CRBT SVR) 175. The callee CRBT_SVR 175 then transmits an ACM message 277 and an answer message (ANM) 280 to the callee VMSC 125. The ACM message 277 indicates that all information required to identify the callee MS/UE 155 has been received by the callee CRBT SVR 175. Next, at block 283, the callee CRBT SVR 175 transmits, through the callee VMSC 125, a color ring back tone to the caller V/GMSC 105, which color ring back tone is then played at a caller telephone. For example, the color ring back tone can be a personalized audio, visual or multimedia presentation that is predefined by a user of the callee MS/UE 155. A more detailed description of a function of block 283 is as follows. After the callee VMSC 125 transmits the ACM 265 to the caller V/GMSC 105, a traffic bearer channel between the callee VMSC 125 and the caller V/GMSC 105 is established. Then, after the callee VMSC 125 receives the ANM 280 from the callee CRBT_SVR 175, a traffic bearer channel between the callee VMSC 125 and the callee CRBT_SVR 175 is established. At block 283, the callee VMSC 125 connects, through the bearer channel between the callee VMSC 125 and the callee CRB T S VR 175, with the bearer channel between the callee VMSC 125 and the caller V/GMSC 105. The callee VMSC 125 thus acts as a transit node between the caller V/GMSC 105 and the callee CRBT SVR 175 in order to transmit the color ring back tone from the callee CRBT SVR 175 to the caller V/GMSC 105. When the call is answered at the callee MS/UE 155, a connect message 285 is transmitted from the callee MS/UE 155 to the callee VMSC 125, which in turns transmits an answer message 288 to the caller V/GMSC 105. At block 290, the callee VMSC 125 connects the call between the caller telephone with the callee MS/UE 155, and bypasses a path through the callee CRBT SVR 175. Finally, when the call is completed, the callee VMSC 125 transmits a release message 293 to the callee CRBT- SVR 175, and the CRBT-SVR 175 responds by sending a release communication (ReI Com) message 295 back to the callee VMSC 125.

As described above, whether an originating MSC (such as the caller V/GMSC 105) or a terminating MSC (such as the callee VMSC 125) is a preferred MSC for connecting to the callee CRBT-SVR 175, instructions can be transmitted from the callee HLR 115 by amending conventional call setup messages. Such conventional call setup messages include Mobile Application Part (MAP) messages. As will be understood by those having ordinary skill in the art, MAP is a Signaling System Seven (SS7) protocol that provides an application layer for various nodes in Global System for Mobile (GSM), Universal Mobile Telecommunications System (UMTS), and General Packet Radio Service (GPRS) core networks to communicate with each other in order to provide services to mobile phone users. MAP is an application-layer protocol used to access elements such as Home Location Registers, Visitor Location Registers, and Mobile Switching Centers. For example, instructions can be transmitted from the callee HLR 115 to the caller V/GMSC 105 by including a supplementary service (SS) code from an SS-List in the SRI Ack message 140. Alternatively, instructions can be transmitted from the callee HLR 115 to the callee VMSC 125 by including an SS-code from an SS-List in the PRN message 230. SS- Lists and SS-Codes are defined in Third Generation Partnership (3GPP) Technical Specifications (TS), including 3GPP TS 29.002 and 3GPP TS 22.004. An available SS-Code that is not used by an existing Supplementary Service can be used to indicate that an MSC should transmit an initial address message (IAM) to a color ring back tone server such as the callee CRBT S VR 175. Referring to FIG. 3, a general flow diagram illustrates a method 300 for instructing a mobile switching center to initiate a transmission of a color ring back tone in a mobile communications network, according to some embodiments of the present invention. At step 305, a home location register processes first data describing a color ring back tone capability of a first mobile switching center. Where the first mobile switching center is a terminating mobile switching center, the first data can be transmitted to the home location register from the first mobile switching center using MAP UPDATE LOCATION signaling. For example, the callee VMSC 125 in the Network 100 can periodically transmit MAP UPDATE LOCATION messages to the callee HLR 115.

At step 310, the home location register processes second data describing a color ring back tone capability of a second mobile switching center. Where the second mobile switching center is an originating mobile switching center, the second data can be transmitted to the home location register from the second mobile switching center using MAP SEND ROUTING INFORMATION signaling. For example, the caller V/GMSC 105 can transmit the SRI message 210 to the callee HLR 115.

At step 315, the first mobile switching center is determined to be a preferred mobile switching center for initiating a transmission of a color ring back tone based on the first data and the second data. For example, at block 220, the callee HLR 115 may determine that the callee VMSC 125 is a preferred mobile switching center for initiating a transmission of a color ring back tone in the network 100, based on a comparison of first data included in MAP UPDATE LOCATION signaling from the callee VMSC 125 and second data included in the SRI message 210 from the caller V/GMSC 105.

At step 320, the first mobile switching center is instructed to initiate the transmission of the color ring back tone. This can comprise transmitting

MAP PROVIDE ROAMING NUMBER signaling from the home location register to the first mobile switching center. For example, the callee HLR 115 instructs the callee VMSC 125 to initiate transmission of a color ring back tone using an SS-Code included in the PRN message 230.

Referring to FIG. 4, a block diagram illustrates system components of the callee HLR 115, according to some embodiments of the present invention. The callee HLR 115 comprises a random access memory (RAM) 405 and a programmable memory 410 that are coupled to a processor 415.

The processor 415 also has ports for coupling to network interfaces 420, 425, 430, which may be wired or wireless network interfaces. The network interfaces 420, 425, 430 can be used to enable the callee HLR 115 to communicate with inter- and intra-network elements in the network 100. For example, the network interface 420 can receive the inter-network SRI message 110 from the caller V/GMSC 105, and the network interface 425 can receive the intra-network PRN Ack message 130 from the callee VMSC 125.

The programmable memory 410 can store operating code (OC) for the processor 415 and code for performing functions associated with a home location register. For example, the programmable memory 410 can comprise initiating CRBT computer readable program code components 435 configured to cause execution of a method for instructing a mobile switching center to initiate a transmission of a color ring back tone in a mobile communications network, as described herein.

Advantages of some embodiments of the present invention thus include enabling a home location register (HLR) in a mobile communications network to determine a preferred mobile switching center (MSC) for initiating a transmission of a color ring back tone (CRBT) to a calling telephone. That can increase a rate of successful transmission of CRBTs. When a call is placed to a mobile telephone that is managed by the HLR, the HLR can identify, based on CRBT capabilities of originating and terminating MSCs, the MSC that is best suited for initiating a transmission of a CRBT based on current network circumstances. Thus a CRBT can be successfully played at a caller telephone—even if a callee telephone has roamed outside of its home network and is no longer capable of initiating a CRBT. Further, the HLR can also consider other network parameters, such as network loading parameters, when determining a preferred MSC for initiating transmission of a CRBT. That can decrease unnecessary network signaling traffic and thus increase overall network efficiency.

It will be appreciated that embodiments of the invention described herein may be comprised of one or more conventional processors and unique stored program instructions that control the one or more processors to implement, in conjunction with certain non-processor circuits, some, most, or all of the functions of instructing a mobile switching center to initiate a transmission of a color ring back tone in a mobile communications network as described herein. The non-processor circuits may include, but are not limited to, a radio receiver, a radio transmitter, signal drivers, clock circuits, power source circuits, and user input devices. As such, these functions may be interpreted as steps of a method for instructing a mobile switching center to initiate a transmission of a color ring back tone in a mobile communications network. Alternatively, some or all functions could be implemented by a state machine that has no stored program instructions, or in one or more application specific integrated circuits (ASICs), in which each function or some combinations of certain of the functions are implemented as custom logic. Of course, a combination of the two approaches could be used. Thus, methods and means for these functions have been described herein. Further, it is expected that one of ordinary skill, notwithstanding possibly significant effort and many design choices motivated by, for example, available time, current technology, and economic considerations, when guided by the concepts and principles disclosed herein will be readily capable of generating such software instructions and programs and ICs with minimal experimentation.

In the foregoing specification, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims.

Claims

We claim:

1. A method for instructing a mobile switching center to initiate a transmission of a color ring back tone in a mobile communications network, the method comprising: processing, at a home location register, first data describing a color ring back tone capability of a first mobile switching center; processing, at the home location register, second data describing a color ring back tone capability of a second mobile switching center; determining that the first mobile switching center is a preferred mobile switching center for initiating a transmission of a color ring back tone based on the first data and the second data; and instructing the first mobile switching center to initiate the transmission of the color ring back tone.

2. The method of claim 1, wherein the first mobile switching center is a terminating mobile switching center and the second mobile switching center is an originating mobile switching center.

3. The method of claim 2, wherein the first data are transmitted to the home location register from the first mobile switching center using MAP UPDATE LOCATION signaling.

4. The method of claim 2, wherein the second data are transmitted to the home location register from the second mobile switching center using MAP SEND ROUTING INFORMATION signaling.

5. The method of claim 1, wherein the first mobile switching center is an originating mobile switching center and the second mobile switching center is a terminating mobile switching center.

6. The method of claim 1 , wherein the first mobile switching center instructs a callee color ring back tone server to transmit a color ring back tone to a caller mobile switching center.

7. The method of claim 6, wherein the caller mobile switching center is the first mobile switching center.

8. The method of claim 6, wherein the caller mobile switching center is the second mobile switching center.

9. The method of claim 2, wherein instructing the first mobile switching center to initiate the transmission of the color ring back tone comprises transmitting MAP PROVIDE ROAMING NUMBER signaling from the home location register to the first mobile switching center.

10. The method of claim 5, wherein instructing the first mobile switching center to initiate the transmission of the color ring back tone comprises transmitting a Send Routing Information Acknowledgement message from the home location register to the first mobile switching center.

11. The method of claim 10, wherein transmitting the Send Routing Information Acknowledgement signaling comprises transmitting a supplementary service code from the home location register to the first mobile switching center.

12. The method of claim 1 , wherein determining that the first mobile switching center is a preferred mobile switching center for initiating a transmission of a color ring back tone is also based on parameters of the network.

13. The method of claim 12, wherein the parameters of the network comprise network loading parameters of inter-public land mobile network signaling.