Method and apparatus for group call services

(54) Title: METHOD AND APPARATUS FOR GROUP CALL SERVICES (30) Unionist Priority: 03/28/2003 us 10 / 402,433 (71) DepOSITANT (s): Motorola, INC. (US) (72) Inventor (s): Nandakishore A. Albal, Peter J. Armbruster, Thomas G. Hallin, Derek A. Oxley, William N. Shores, William R. Worger, George Xanakis (74) Attorney: Orlando de Souza (86) International Application: pct US04 / 007297 of 11/03/2004 (87) International Publication: wo 04/095787 of 11/04/2004 (57) Abstract: METHOD AND EQUIPMENT FOR GROUP CALL SERVICES. The voice signaling portal (ÍO) provides group call and callback services between users on the iDEN network (20) and a number of several other users (3162) on networks (30-60). The voice signaling portal has a patched data interface (17) and a web interface (16). In an alternative version of the service, an integrated application server (70) is added to the voice signaling portal (100) to provide group call services. The integrated application server has the functions to support group calls that were within the voice signaling portal (10) 'and forms an independent special resource system. - * '.

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METHOD AND APPARATUS FOR GROUP CALLING SERVICES History of the Invention

The present invention pertains to group call services and, more particularly, to group call services through a plurality of networks.

Today, group call services are provided by specialized networks such as iDEN (integrated digital enhanced network). The group call is one in which the originator selects a person or persons with whom he wishes to speak and the target user's phone immediately transmits the originator's words, without the typical phone call and response. In an alternative version, the group call can be presented to the target for acceptance by the target. Another group call service is referred to as Callback. This service provides the target's ability to assemble or reinstate a group call that has already been established.

The iDEN system is a closed system that offers group call services to those customers who are currently on the iDEN TDMA (multiple time division) network. Other networks such as CDMA (code division multiple access), GSM (global mobile system), IP (Internet protocol) and 802.11 do not currently support group calling services. Non-iDEN subscribers may wish to make group calls to the existing customer base of iDEN subscribers and vice versa or to mixed iDEN groups and non-iDEN groups.

Users of group call services are typically organized into speech groups. Speech groups usually contain users who share a mission in ί

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common, as a working group. Working groups may be brought together such that not all users are uniformly iDEN or non-iDEN. Current dispatch call systems are not able to facilitate the connection of such diverse users.

Dispatch systems have been provided to alleviate this problem; however, these group call systems involve many limitations, including missed calls, poor audio quality, and gaps in speech.

Thus, there is a need to provide group call services for non-iDEN systems and between iDEN users and non-iDEN systems.

Short Description Of Drawings

Figure 1 is a block diagram of a system for facilitating group calls between iDEN networks and several non-iDEN networks through a portal according to the present invention.

Figure 2 is a flow chart of a method for group calls between iDEN users and non-iDEN users according to the present invention.

Figure 3 is a block diagram of a system for facilitating group calls between iDEN networks and several non-iDEN networks through an integrated application server according to the present invention.

Description of the preferred version of the invention

Group call services are becoming more widespread. Non-iDEN subscribers need to make group calls to the existing customer base of millions of iDEN subscribers and vice versa.

The present invention includes the introduction of a new • 9 9 9 9 9 9 9 · · · · · · · · ·· · · ······ · ···· ·· ·

3/12 network element called the voice signaling portal (VSGW). VSGW provides signaling and carrier conversion of all traffic between an iDEN network and non-iDEN networks. VSGW is network agnostic on the non-iDEN network end. VSGW can be used with CDMA (Code Division Multiple Access), GSM (Global Mobile System), 802.11 (as wireless LANs) and the traditional IP (Internet Protocol) for group call services. The present invention does not require that elements of the iDEN network be modified, nor does the present invention require that iDEN users be aware that they are communicating with users on a non-iDEN network.

With reference to Figure 1, a block diagram of the voice signaling portal 10 is shown interconnected between the iDEN 20 network and a number of non-iDEN networks 30-60. The voice signaling portal (VSGW) 10 provides group call and call back services to iDEN and non-iDEN subscribers. VSGW 10 uses DAP-DAP signaling with the DAP iDEN, and SIP signaling with the non-iDEN call engines to establish group calls and callbacks. SIP is defined by the IETF RFC3261.

VSGW 10 allocates carrier resources for SIP dispatch calls to DAP and vice versa. DAP 24 is a dispatch application server that processes dispatch requests within the iDEN 20 network. VSGW 10 resembles DAP on the iDEN 20 network side and a SIP engine on the non-iDEN side. IHLR 22 is the iDEN home location register. IHLR is a database that includes subscriber records / profiles and rules that dictate how the dispatch call should be handled for subscribers • ·

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iDEN. The iHLR is the place where the iDEN 21 subscriber, for example, is registered on the network that provides service to the subscriber 21. The iHLR 22 stores the subscriber's profile and records, and the DAP 24 identity where the subscriber is registered.

iDAC 2 6 is the iDEN dispatch audio controller. For the iDEN 20 network, iDAC 26 handles the voice load in a proprietary format called iRTP. DAP 24 provides carrier traffic control for iDAC 26 over connection 25. VSGWb 12 from voice signaling portal 10 behaves like iDAC 26. Voice load on non-iDEN networks adhere to the RTP standard and conversion the protocol between RTP and iRTP is performed by VSGWb 12. RTP is defined in the IETF

RFC 1889.

The voice signaling portal 10 includes the voice signaling portal carrier control 12 and the voice signaling portal signaling control 14. VSGWs 14 is coupled to the iHLR 22 and DAP 24. The VSGWb 12 is coupled to the iDAC 26.

0 VSGW 10 also includes a packet duplicator 13 which is coupled to VSGWb 12. The packet duplicator duplicates voice packets multi-directionally and can optionally exclude the speaker.

The VSGW 10 also includes a packet data interface 17 that is coupled to the database 15. 0 VSGW 10 also includes a web interface 16 that is coupled to a database 15. Note that the term web interface is not intended to only include interfaces that adhere to the HTTP, XML and WAP protocols but also to their derivatives. The packet data interface is used by devices

5/12 subscriber to access applications on VBSGW 10 and define, update, modify and delete group definitions. The Web interface 16 provides another mechanism for end users to access the applications mentioned above and define groups. The provisioning interface 19 allows carrier / operator personnel to define groups and store them in the database 15. VSGW 10 includes a database 15 that stores group definitions, membership, profile and characteristics. Database 15 is coupled to the provisioning interface 19, to the packet data interface 17, to the web interface 16 and is also coupled to VSGWs 14. Finally, VSGW 10 includes a pseudo iHLR (PiHLR) 18 that contains location information associated with the group call. It should be obvious to those skilled in the technology that PiHLR could also contain subscriber profiles for non-iDEN subscribers and the specific group profile. DAP 24 communicates with PiHLR 18 using the MAP protocol. In addition, VSGWs 14 communicates with iHLR 22 using the protocol

MAP.

MAP is an abbreviation for part of the mobile application and is a standard base protocol that allows real-time communication between nodes on a mobile cellular network. A typical use of the MAP signaling protocol is to transfer location information from a visitor location recorder (VLR) that is within the DAP to the iDEN residential location recorder (iHLR) 22. The MAP includes a layer in the seven standards signaling system that is used by GSM networks and

UMTS (Universal Mobile Telecommunication System). The standard • · · · • ·

6/12 is defined by ETSI TS129120V3.0.0.

The web interface 16 allows the CDMA (code division multiple access) network 30, the GSM network (mobile global system) 40, the 802.11 network (such as the wireless LAN) 50 and the IP network (Internet protocol) 60 access the database.

VSGW 10 includes packet duplicator 13, group call engine VSGWs 14 and VSGWb 12 and, in the preferred version, speaker's arbitration capabilities are provided through packet duplicator 13. It should be obvious to those enabled in technology that the speaker's arbitration capabilities could be included in VSGWs 14, DAP 24, or other call control entities on non-iDEN 30-60 networks. The VSGW 10 database 15 provides a data warehouse for group definitions (ie, which users are in a particular group) and interfaces (for example, packet data and web interfaces) to allow each defined group to have members of the iDEN network and / or non-iDEN networks

0 as mentioned above. In addition, database 15 may be provisioned to provide services similar to iHLR for users who access dispatch services over the IP 60 network.

First, VSGW 10 as shown in Figure 1 provides group calls provided by the operator. The network or system operator defines membership as a member of a group call within VSGW 10 via operator console 90. The group definition is stored within VSGW 10 in database 15. As a result of the call definition groups in VSGW 10, members of the

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7/12 group may be subscribers on TDMA iDEN networks, TDMA non-iDEN networks or a combination of TDMA iDEN and TDMA non-iDEN network subscribers.

Any individual subscriber 21-62 will be able to make a call to VSGW 10 with the designated group call identity. VSGW 10 receives the request and translates the group call identity into a list of members using the database 15. VSGW then launches the call for each member of the group 21-62.

Assuming that the call was originated by subscriber 21, each member of the group 31-62 is presented with the call from the group call originator, subscriber 21. Some subscribers on non-iDEN 30-60 networks may be informed that this is a a group call with flexibility to provide session initiation protocol (SIP) signaling. When the first subscriber member of the group call 31, for example, joins the call, the packet duplicator 13 bridges the call or transmits the data packet from the member subscriber of the originating group call 21 to the subscriber 31. In version preferred, for the duration of the group call, packet duplicator 13 performs the speaker arbitration function. That is, packet duplicator 13 determines which subscriber 21-62 is capable of being the speaker at any individual time. In an alternative version, speaker arbitration may not be necessary if the networks support full duplex voice communication.

If subscriber 62 joins the group call, for example, the packet duplicator 13 transmits the packets also to subscriber 62 via IP network 60.

Second, for the group's provision group calls

8/12 user, subscriber 21, for example, accesses VSGW 10 through the packet data interface 17. As a result, the user provision group call leads to defining a group of members similar to the group calls provisioned by the operator above and generates a group call identity. This group call identity is stored in the VSGW 10 database 15. The originating subscriber 21, for example, then makes a call indicating the group call identity and the call proceeds as explained above for the operator-provisioned group call.

For group calls provisioned by the operator and provisioned by the user mentioned above, the database maintains group definitions for a variable period of time. Another type of group call that the subscriber can invoke is the SDGC (Dynamic Selective Group Call). In SDGC, the user dynamically selects a set of group call participants (for example, from an address book) and posts a call request to VSGW 10. In one version, the lifetime of this dynamic selective group definition is maintained for the life of the call. In another version, the group definition is kept for a short time after the initial call has ended. In the first case, the database 15 does not store the group definition, while in the latter case it is stored for the specified life of the selective dynamic group to support the callback service.

Third, for a selective dynamic group call, subscriber 21 originates access to VSGW 10 via packet data interface 17 or a request for

9/12 selective dynamic group call directly to VSGWs 12. Originating subscriber 21 then dynamically defines the group call members with VSGW 10. The definition can be stored dynamically within the database

15 VSGW 10, or obtained directly from subscriber 21 by

VSGWs 14. The VSGWs 14 initiates an SDGC for each member of the group call based on information provided directly by subscriber 21 or data in database 15. The SDGC includes the identity of the group call, and the call flows are as indicated above for the operator-provisioned group call.

Figure 2 is a flow chart of the VSGW 10 call processing. The starting block is entered and control is transferred to block 69. Block 69 transfers control to block 72. Block 72 determines whether the request is for a call or a group call. If the request is for a call, block 72 transfers control to block 74. Block 74 typically processes the private call.

If the request is for a group call, the block transfers control to block 76 via the GC route. Block 76 determines whether the group call is valid. For example, if the group call identity is valid. If not, block 76 transfers control to block 84

5 through the street. Block 84 provides error handling.

If the group call is valid, block 76 transfers control to block 78 via route Y. Block 78 expands the group list to produce a single request group call.

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Then, block 80 launches a private call for each of the group members indicated in the database. Then block 82 determines whether the response to each of the private calls is within a predetermined end in time. If not, block 82 transfers control to block 84 for error handling.

If the response made by each member of the group call was within the timeout, block 82 transfers control to block 86 where the individual legs of the group call are punctuated by packet duplicator 13. That is, it interconnects each of the subscribers 21-62.

Then block 88 determines whether the connected group call is ready for speech. If not, block 88 waits until the group call is ready to speak. If the group call is ready for speech, block 88 transfers control to block 90 via route Y.

Block 90 causes the packet duplicator to arbitrate the speaker. That is, packet duplicator 13 determines who the next speaker is and transmits that subscriber's speech to each of the group call subscribers. Then block 92 determines whether the group call is active. If it is, block 92 transfers control to block 8 8 via path Y to determine when a new speaker is ready to speak. The process of blocks 88, 90 and 92 is then iterated. If the group call is no longer active, block 92 transfers control to block 94 via the via. Block 94 ends the call.

Now, moving on to Figure 3, an alternative version of the present invention is shown. In this version of

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VSGW 10 has been replaced by a modified VSGW 100 and an integrated application server 70. The integrated application server (IAS) 70 may be functionally located away from the VSGTW 100. The processing of the group call that was in VSGW 10 is now moved to IAS 70. IAS 70 now includes a group 71 signaling controller.

GCs 71 is coupled to the packet duplicator 13. The packet data duplicators of Figures 1 and 3 are from the equivalent period.

GCs 71 is coupled to database 15. Database 15 is coupled to web interface 16, packet data interface 17 and provisioning interface 19. Each of these functions 15, 16, 17 and 19 provide the same functions as described for blocks 15, 16, 17 and 19 in VSGW 10 in Figure 1. The arrangement in Figure 3 gives the flexibility to provide a separate server, IAS 70, to handle group calls, and to have a VSGW 100 that provides an iDEN portal function. IAS 70 processes group calls as explained in Figure 2. The processing of IAS 7 0 for operator-provisioned group calls, user-provisioned group calls and selective dynamic group calls is identical to the processing explained in Figure 2 for VSGW 10. That is, for this version of the invention the ability to handle group calls has been removed from VSGW 10 and placed on a separate server, IAS 70. The VSGW 100 contains the functions of VSGWs 14, VSGWb 12, and PiHLR 18 as explained in Figure 2.

In view of the above, it can be appreciated that the

12/12 • · · · · ···· · the present invention provides a group call and callback service that are independent of the network. In addition, group calling and callback features may serve subscribers of conventional TDMA iDEN networks as well as CDMA, GSM, 802.11 and IP networks. This invention provides a standard-compliant interface on the non-iDEN TDMA interface and does not require changes to TDMA iDEN networks. In addition, TDMA iDEN handsets can be established between TDMA iDEN subscribers and non-iDEN TDMA subscribers. This provides group call interconnections for many, many subscribers.

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