Patent Publication Number: US-11659471-B2

Title: System, method, and apparatus for using alternative numbers for routing voice calls and short messages in a communications network

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. Ser. No. 15/457,474, filed on Mar. 13, 2017, now U.S. Pat. No. 10,820,255, issued on Oct. 27, 2020, which is a continuation of U.S. Ser. No. 14/605,761, filed on Jan. 26, 2015, now U.S. Pat. No. 9,596,353, issued on Mar. 14, 2017, which is a continuation of U.S. Ser. No. 14/140,497, filed on Dec. 25, 2013, now U.S. Pat. No. 8,942,664, issued on Jan. 27, 2015, which is a continuation of U.S. Ser. No. 13/846,991, filed on Mar. 19, 2013, now U.S. Pat. No. 8,634,800, issued on Jan. 21, 2014, which is a continuation of U.S. Ser. No. 13/307,112, filed on Nov. 30, 2011, now U.S. Pat. No. 8,412,241, issued on Apr. 2, 2013, which is a continuation of U.S. Ser. No. 11/750,756, filed on May 18, 2007, now U.S. Pat. No. 8,086,254, issued on Dec. 27, 2011, the entire disclosures of which are incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure relates to telecommunications and, more particularly, to telecommunications including voice calls and short message service, enterprise servers, wireless communications, and the interoperability of communication technologies. 
     BACKGROUND 
     Corporations are increasingly relying on the use of cellular technology by their employees, yet enterprises do not have adequate means to control cellular service in terms of costs, Quality of Service, and corporate monitoring. This is because cellular service has conventionally been controlled by wireless carrier networks and managed independently of, and with no connectivity to, the enterprise voice and data networks. 
     Enterprises today control their enterprise fixed voice and data networks by deployment of private branch exchanges (PBXs). The enterprise may own and manage PBXs within each branch and between branch offices. The enterprise may also own and manage their own data networks and corporate local area network (LAN)/wide area network (WAN). Bulk voice minutes and data capacity may be purchased from land-line carriers, or from other providers that have purchased bulk minutes and data capacity from carriers. The purchased capacity may then be used to connect branch offices using public IP Network providers, e.g., MCI, Sprint, L3, etc., for Data and Voice over IP (VoIP). Heretofore, no mechanisms have been provided to extend the enterprise fixed voice and data networks paradigm to cellular services. 
     SUMMARY OF THE INVENTION 
     Embodiments disclosed herein provide mechanisms for enabling the use of an alternative numbering plan for delivering voice calls and short messages to mobile subscribers using the public mobile telephone network. Using the methods described herein, users of an enterprise or other closed networks as well as users that are not part of a closed network may send short messages destined to members of an enterprise or closed network from their mobile or other devices associated with their subscription using an alternative enterprise directory number. The alternative enterprise directory number may comprise an office number of a land-line telephony device. In accordance with embodiments, the alternative enterprise directory number, rather than the mobile number, will be presented at the destination device as the originating number. The recipient can respond to the message by addressing the response to the enterprise or closed network number and it will be delivered to the originator&#39;s mobile or other devices associated with their subscription. The disclosure additionally addresses alternative routing of voice calls directed to the enterprise or closed network numbers such as when the public landline networks is not available during an emergency, as well as addressing potential routing conflicts between the public mobile and land-line networks. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures, in which: 
         FIG.  1    is a diagrammatic representation of a network architecture in which embodiments disclosed herein may be implemented; 
         FIG.  2    is a diagrammatic representation of another network architecture featuring split call control in accordance with an embodiment; 
         FIG.  3    is a diagrammatic representation of an embodiment of gateway server implemented in accordance with an embodiment; 
         FIG.  4 A  is a diagrammatic representation of an exemplary HLR record that defines a subscriber profile implemented in accordance with an embodiment; 
         FIG.  4 B  is a diagrammatic representation of an exemplary HLR dummy record that may be associated with a land-line telephony device that facilitates one number services implemented in accordance with an embodiment; 
         FIG.  5    is a simplified diagrammatic representation of an exemplary SMS message format implemented in accordance with an embodiment; 
         FIGS.  6 A- 9 C  are diagrammatic representations depicting signaling flows of an SMS transmission and representative SMS messages in a network system implementing one number servicing in accordance with a embodiments; 
         FIG.  10    is a diagrammatic representation depicting a signaling flow for handling of mobile originations for voice calls to an enterprise number which is provisioned in a mobile network HLR in accordance with an embodiment; 
         FIG.  11    is a flowchart of exemplary SMS message processing as may be implemented by an enterprise gateway server that facilitates one number service in accordance with an embodiment; and 
         FIG.  12    is a diagrammatic representation depicting a signaling flow for handling of mobile originations for voice calls to an enterprise number which is provisioned in a mobile network HLR in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. 
     With the ubiquity of cellular communication devices, it is desirable to seamlessly integrate public wireless voice and data networks with enterprise networks. More particularly, it is desirable to provide enterprise cellular solutions that may operate in conjunction with public network infrastructure. While enterprise-provisioned cellular services may provide enhanced personnel communications and connectivity, the variety of user communication devices, e.g., land-line phones, cellular phones, personal digital assistants, and the like, may introduce challenges for providing timely delivery of communication services. For example, enterprise personnel may be assigned numerous communication devices, such as a land-line phone for use when the employee is at a work station or office, and a cellular phone or a personal digital assistant when the employee is away from the office either at other locations in the enterprise or outside the enterprise premises. Because the employee may be equipped with communication devices best suited for use when the employee is at a particular location as well as a mobile communication device for use when the employee is on the move, persons attempting to contact the employee may not be aware of the best means for communication with the employee at a particular time. 
     In accordance with the present disclosure, the enterprise is able to equally extend the enterprise fixed voice and data networks paradigm to cellular services by connecting the public wireless voice and data network with the enterprise. A gateway server inter-connects the carrier&#39;s Mobile Switching Center (MSC) that manages cellular voice traffic as well as the carrier&#39;s Serving GPRS Support Node (SGSN) that manages cellular data traffic, with the enterprise&#39;s voice and data network. In accordance with a particular embodiment, a one number service feature may be provided that allows the enterprise subscribers or personnel the use of multiple communication devices with a single enterprise directory number. An enterprise member may be assigned a land-line phone and a cellular telephone and may be only aware of the enterprise directory number of the land-line phone. Likewise, colleagues or personal contacts may only be provided with the enterprise member&#39;s land-line phone number yet may advantageously contact the enterprise member on both the enterprise member&#39;s land-line phone and cellular telephone using the land-line phone number assigned to the enterprise member. More particularly, an enterprise member may originate short message service (SMS) messages from the mobile terminal assigned to the member. The MSISDN number of the originating mobile terminal may be replaced with the land-line phone number assigned to the member when the SMS message is in transit. Accordingly, a destination user that receives the SMS message will be presented with the land-line number of the originating member. In a similar manner, a contact of the enterprise member may originate an SMS message to the member using the member&#39;s land-line enterprise directory number as the destination number of the SMS message. The enterprise land-line number entered as the destination number may be replaced with the land-line phone number assigned to the member when the SMS message is in transit. Accordingly, the enterprise member may then receive the SMS message on the member&#39;s mobile terminal although the SMS message was originally addressed to the land-line phone number. 
       FIG.  1    is a diagrammatic representation of a network  100  architecture in which embodiments disclosed herein may be implemented. Network  100  may include a cellular network system  110 , such as a Global System for Mobile (GSM) Communications network, a code division multiple access (CDMA) network, a mobile network utilizing IMT-2000, or another suitable mobile network. Cellular network system  110  generally includes a Switching System (SS)  120  and a Base Station System (BSS)  130 . In the examples provided herein, mobile network architecture components are made with reference to the GSM, the most popular standard for mobile phones in the world. GSM is both an air interface and networking protocol. The most popular alternative combines the Code Division Multiple Access (CDMA) air interface protocol and the ANSI-41 networking protocol. 
     Each of SS  120  and BSS  130  contain a number of functional units well understood by those skilled in the art, and a detailed explanation of the various components is unnecessary. Nevertheless, a cursory review of various components is provided. SS  120  contains a Mobile services Switching Center (MSC)  122 , a Home Location Register (HLR)  124 , and a Visitor Location Register (VLR)  126 . MSCs carry out switching functions and manage the communications between mobile phones and the Public Switched Telephone Network (PSTN)  190 . HLR  124  comprises the central database that contains details of each mobile phone subscriber that is authorized to use the cellular core network. VLR  126  comprises a database which stores information about all the mobiles terminals that are currently serviced by the associated MSC (MSC  122  in the present example). VLR  126  stores various information regarding the mobile terminals, such as the current location area identity that specifies a particular base station controller (BSC) that the mobile station is currently serviced by. 
     Various other sub-systems or functional modules may, and typically are, included in SS  120 , such as an Authentication Center, an Equipment Identity Register, or various other functions. A serving general packet radio service (GPRS) support node (SGSN)  128  may be included in cellular network system  110  to facilitate provisioning of packet services to and from mobile terminals in network system  110 . GPRS provides mobility management, session management and transport for Internet Protocol packet services in GSM cellular packet networks. 
     As is understood, various GPRS infrastructure may be included in network system  110  to provide packet services to mobile terminals, and only SGSN  128  of the GPRS core network is depicted to simplify the discussion of embodiments disclosed herein. In general, a gateway GPRS support node may interface the GPRS backbone with an external packet network, such as the Internet. 
     SGSN  128  may interface with various subsystem of network system  110 . For example, SGSN  128  may have a Gs interface with MSC  122  and VLR  126  that facilitates paging and station availability notification when performing data transfers. SGSN  128  may additionally have a Gr interface with HLR  124  through which messaging may be performed, for example, over the Mobile Application Part protocol. SGSN  128  may additionally have a Gb interface with packet control unit (PCU) (not shown) of BSS  130  that facilitates connection of BSS  130  with SGSN  128 . 
     Network system  110  may also include a signaling system, such as a SS7 network  160 . SS7 network  160  provides a set of telephony signaling protocols which are used to set up the vast majority of the world&#39;s PSTN telephone calls. SS7 network  160  is also used in cellular networks, such as GSM and UMTS, for circuit switched voice and packet-switched data applications. As is understood, SS7 network  160  includes various signaling nodes, such as any number of service control points (SCPs)  162 , signal transfer points (STPs)  164 , and service switching points (SSPs)  166 . 
     BSS  130  contains a Base Station Controller (BSC)  132  that may be in communication with and in control of a plurality of Base Transceiver Stations (BTSs)  134 - 138 . Each individual BTS  134 - 138  under the control of a given BSC  132  may define a radio cell operating on a set of radio channels thereby providing service to a Mobile Terminal (MT)  140 . 
     Network system  110  may also include a short message service center (SMSC)  144  adapted to deliver short message service (SMS) messages to mobile terminals. When an SMS message is sent to a user, the SMS message is stored in SMSC  144  which delivers it to the destination mobile terminal when the destination mobile terminal is available. As is known, the SMS message may be delivered via a control channel, e.g., a cell broadcast control channel, or bearer channel. 
     Network  100  may include an enterprise network  150 , such as a switched Ethernet, that interconnects various network nodes via various network infrastructure, such as hubs and switches. In the illustrative example, enterprise network  150  includes various client nodes, such as desktop clients  152  and  153 , land-line Internet Protocol (IP) telephones  154 - 155 , and an IP private branch exchange (PBX)  158  which carries calls over IP, e.g., via voice over IP (VoIP). Enterprise network  150  may interface with the PSTN  190  via a router  172  disposed at the enterprise. 
     Likewise, enterprise network  150  may interface with cellular network system  110  via routers  170  and  172 . It is understood that enterprise network  150  may, and typically does, include hundreds or thousands of client devices and networking nodes, and the architecture depicted in  FIG.  1    is greatly simplified to facilitate a discussion of embodiments disclosed herein. 
     In accordance with an embodiment, an enterprise gateway server  180  may be deployed in enterprise network  150  that is adapted to inter-connect the mobile network&#39;s MSC  122  that manages cellular voice traffic as well as the SGSN  128  that manages cellular data traffic. Enterprise gateway server  180  may include or interface with a softswitch media gateway  181 . From an IT organization perspective, gateway server  180  appears as an extension to PBX  158 . To cellular network system  110 , gateway server  180  appears as a standard in-network endpoint for delivering calls. To PBX  158 , gateway server  180  appears as a set of standard PBX endpoints (e.g. deskphones, or IP clients). Gateway server  180  mediates between the two disparate sets of network protocols and state machines. 
     Gateway server  180  may include the network functions for both voice (gateway MSC) and data (gateway GPRS Support Node or Home Agent), VoIP capability for interconnecting mobile network  110  with enterprise network  150  thereby eliminating PSTN interconnect charges, a billing gateway, and a next-generation Network Services gateway that enables third party value added services for the enterprise, such as mobile phone activation/de-activation, corporate directory integration based on IMS (IP Multimedia Subsystem), or other services. Gateway server  180  may also include the element management subsystem (EMS) and a service management subsystem for the operational support system (OSS). 
     In the example depicted in  FIG.  1   , call control may be managed by the enterprise in which the gateway server is located. In this implementation, the gateway server interfaces with cellular network system  110  nodes supporting SS7 and SIP or other messaging with the carrier network, and the cellular network must be able to address gateway server  180  in order to send and receive messages. 
     In another embodiment, call control may be split or partitioned between the carrier and enterprise networks as depicted in the network configuration  200  of  FIG.  2   . In this implementation, an enterprise gateway server (GS-E)  182  interacts with a carrier gateway server (GS-C)  180  deployed in the carrier network. The connection between GS-E  182  and GS-C  180  may be made over SIP or other protocols. This configuration may enable cellular network system  110  to have a central point of control for interacting with multiple enterprises, and may not require the use of SS7 messaging to the enterprise. Rather, it is possible to have a secure IP connection supporting SIP. This is also useful for offering a Centrex solution for interconnecting with a carrier-hosted PBX, or for interconnecting a carrier-hosted gateway server with enterprise-hosted PBX  158  systems. GS-C  180  may support an SS7 point code multiplexer in which only one or two point codes are needed to address all enterprises since GS-C  180  can identify for which enterprise the message is intended. In the illustrative example, GS-C  180  has a point code “Point Code A ” and softswitch media gateway  181  has a point code “Point Code B ”. GS-E  182  may be adapted to provision GS-C  180  automatically over the IP interface to manage subscribers, e.g., to add new pilot directory numbers (DNs) for new subscribers. In this case, originating and terminating triggers used in cellular network system  110  for routing calls to GS-C  180  can add identifying information of the specific enterprise in the triggering messages. Alternatively, GS-C  180  may identify the enterprise based on the calling party information. 
     In the illustrative examples provided herein, Party A and Party B are both members of enterprise network  150 . Party A is assigned a mobile terminal  140  having an MSISDN of 1-972-444-1001, and Party B is assigned a mobile terminal  141  having an MSISDN of 1-972-444-1002. Party A is assigned enterprise land-line telephony device  154  having an enterprise directory number of 1-972-555-2001, and Party B is assigned enterprise land-line telephony device  155  having an enterprise directory number of 1-972-555-2002. Additionally, Party A and Party B are assigned a respective desktop client  152  and  153 . In some examples, reference is made to another mobile terminal user, Party C, that is not a member of enterprise network  150 . In the illustrative example, Party C is assigned a mobile terminal  142  having an MSISDN of 1-214-777-7777. 
     GS-E  182  may include or interface with an Enterprise member database  190  that stores records or profiles that define services for members of enterprise network  150 . Enterprise member database  190  may facilitate one number servicing implemented in accordance with embodiments by associating a land-line telephony device and a mobile terminal commonly assigned to a particular enterprise member. For example, enterprise member database  190  may include a record  190   a  allocated for Party A that is a member of enterprise network. In the illustrative example, record  190   a  includes a Land-line field that stores an enterprise directory number of a land-line telephony device  154  assigned to Party A, and an MSISDN field that stores a directory number of mobile terminal  140  assigned to Party A. In this manner, the land-line number and the directory number (MSISDN) of the mobile terminal of the user Party A are associated with one another. In a similar manner, Party B that is a member of enterprise network  150  has a record  190   b  that associates the enterprise directory number of an enterprise telephony device  155  assigned to Party B with the mobile number of mobile terminal  141  assigned to Party B. 
     In general, exemplary processing routines described herein are provided with reference to a split call control configuration featuring both enterprise and carrier gateway servers. However, embodiments disclosed herein are not limited to such a configuration and may be similarly implemented in a system deploying a gateway server in the enterprise as depicted in  FIG.  1    as will be apparent to those skilled in the art. 
       FIG.  3    is a diagrammatic representation of an embodiment of gateway server  180  depicted in  FIG.  1   . Gateway server  180  includes hardware and an operating system  310 , such as an instance of the Unix operating system. Various protocol stacks may be deployed and run by the gateway server. In the illustrative example, the gateway server includes a network layer  320 , such as an Internet Protocol layer. Transport layer(s), such as user datagram protocol (UDP)  322 , transport control protocol (TCP) layer  324 , and stream control transmission protocol (SCTP) layer  326 , may be included in the gateway server and interface with the lower network layer  320  and applications above the transport layer. Application layers that interface with lower transport layers may include a session initiation protocol (SIP) layer  328  for creating, modifying, and terminating sessions with one or more devices and H.323 compliant layer  330  for provisioning of communication sessions over a packet network. The gateway server additionally includes mobile networking protocol layers, such as ANSI-41 and GSM layers  332 . Advanced intelligent network and wireless intelligent network capabilities may be provided by the gateway server via, for example, a Customized Applications for Mobile networks Enhanced Logic (CAMEL) layer  334  and/or a wireless intelligent network (WIN) layer that allows an operator to define services over and above standard services provided by the GSM standards. The gateway server may include any variety of applications, such as H.323 communication application  340 , an element management subsystem  342 , a short message service system  344 , BGW  346 , and an application programming interface  348 . Additionally, the gateway server may include a session initiation protocol layer  350 , gateway GPRS support node home agent application  352 , gateway mobile services switching center  354 , session control protocol  356 , and home location register/home subscriber server application  358 . Various other applications may be included in addition to, or in lieu of, any one or more of the depicted applications. 
     The gateway server enables the enterprise to manage and control its cellular service in addition to providing a significant overall cost reduction for telecommunications. Moreover, the gateway server includes an overall platform and architecture for improved and integrated wireless enterprise solutions and facilitates convergence between the enterprise&#39;s cellular and Voice over IP (Internet Protocol) infrastructure. 
     The gateway server leverages the benefits of Voice over IP with cellular to extend the cellular network into the enterprise. The gateway server addresses both cellular voice and data, and is a networking solution that works together with the enterprise&#39;s existing PBX, performing mobile call control functions (routing and services). 
     Additionally, the gateway server bridges the enterprise PBX and public cellular environments to enable telecom applications for the cellular user, such as short-code dialing (e.g. 4 and 5-digit dialing), one number service (one phone number for the land-line and cellular phone), and single voice mail box that services both a user&#39;s land-line and cellular telephone. The gateway server enables the enterprise to leverage existing telecom assets for cellular use (e.g., least-cost routing over a corporation&#39;s VoIP or leased-lines network for discounted long distance; use of existing PBX voicemail system). 
     The gateway server is an application platform for deploying mobile IT applications. Either the enterprise IT department or a Systems Integrator may develop and integrate specific applications to interface with the corporation&#39;s cellular devices. For example, the enterprise can choose to replace the desk phone of an office employee with an inexpensive mobile phone. For this employee, when they ‘badge-out’ of the building at the end of the day, the enterprise security budging system can be used to inform the gateway server to de-activate the mobile phone, until the employee returns to the office and ‘badges-in’ the next morning. Alternatively, the gateway server can track and record the calls made outside the office hours, and enable the enterprise to charge them to the business, to the employee, or record them as a corporate benefit. 
     The gateway server may be a software-only solution that can execute on standard, inexpensive Linux platforms. The gateway server may comprise a mobile core network (for call handling and routing) and services network (voice and data services such as PBX-based short code dialing, voicemail, conference calling, VPN, etc.) components. It may be appropriately scaled down to the smaller subscriber base of a decentralized large enterprise, in the order of hundreds to several thousand subscribers, compared with carrier systems that manage many millions of “centralized” subscribers. The gateway server is designed to be managed and maintained by the same IT group that currently manages the enterprise&#39;s PBX system. 
     In accordance with an embodiment, one number service provides for call termination with multiple terminals, e.g., a land-line phone and a cellular telephone. An enterprise employee may be assigned a land-line phone and a cellular telephone and may use a single destination number for either device for receiving and originating telephone calls and data service. Accordingly, users attempting to contact an enterprise employee need only have a single phone number assigned to the employee for making a phone call to either the employee&#39;s land-line phone or cellular telephone. In accordance with a particular embodiment, short message service (SMS) messages may be originated by an enterprise employee from a cellular telephone assigned thereto, and the SMS message may ultimately be delivered to a destination device with the land-line enterprise directory number associated with the originating employee included in the SMS as the origination number. Thus, an enterprise employee originating a SMS message from a cellular phone may have the SMS message delivered to the target device whereupon the SMS message is displayed as originating from the enterprise employee land-line phone number. In a similar manner, a person originating an SMS may enter the land-line number of an enterprise employee, and the MSISDN assigned to the cell phone of the enterprise employee may be substituted for the land-line number by the gateway server (either the GS-E or GS-C) and subsequently delivered to the enterprise employee&#39;s cell phone. In this manner, a user may be only aware of the employee&#39;s land-line enterprise directory number but may advantageously deliver SMS messages to the enterprise employee&#39;s cell phone as will be described more fully hereinbelow. 
       FIG.  4 A  is a diagrammatic representation of an exemplary HLR record  400  that defines a subscriber profile implemented in accordance with an embodiment. In general, HLR  124  may, and typically does, include thousands of records each associated with a particular mobile subscriber. Each HLR record includes details of a respective subscriber authorized to use cellular network  110 . In the illustrative example, HLR record  400  is representative of an HLR record allocated for Party A&#39;s mobile terminal (mobile terminal  140  in  FIGS.  1  and  2   ) in the depicted Figures. 
     HLR record  400  comprises a plurality of fields  402 - 420  which each store information regarding a particular mobile terminal assigned to a subscriber of cellular network  110 . Fields  402 - 420  have respective labels of “IMSI”, “MSISDN”, “Voice”, “SMS.”, “GPRS_Settings”, “VLR_ID”, “SGSN_ID”, “SMS-CSI”, “SMSC_Number,” and “MSC_ID”. A particular field, e.g., IMSI field  402  and MSISDN field  404 , may be designated as a key field and each respective data element is unique within key fields  402 - 404 . 
     In the illustrative example, IMSI field  402  maintains an International Mobile Subscriber Identity (IMSI) stored in the subscriber identity module (SIM) of the mobile terminal for which HLR record  400  is allocated. The IMSI comprises a unique number associated with a particular mobile terminal. The IMSI is typically a 15-digit number having the first 3 digits that specify a mobile country code followed by a 3-digit mobile network code associated with cellular network  110  to which the mobile terminal is registered. The remaining digits may comprise a mobile subscriber identification number (MSIN) assigned to the customer (Party A in the present example) associated with the mobile terminal. In the illustrative example, the IMSI has a value of “3101501234567890” assigned thereto. 
     A mobile subscriber ISDN (MSISDN) field  404  may store the MSISDN, or directory number, assigned to the mobile terminal for which record  400  is allocated. In the illustrative example, the MSISDN field  404  specifies a MSISDN number of “19724441001”, that is the directory number assigned to mobile terminal  140 . Each of IMSI field  402  and MSISDN field  404  may be used as primary keys for accessing HLR record  400 . 
     HLR record  400  may record various subscription services for the mobile terminal. In the illustrative example, various service fields may have values that indicate whether the subscriber for which the HLR record is allocated is authorized to use a particular service. In the present example, Voice field  406  has a value of true (T) that indicates that associated subscriber is authorized for voice service, and SMS field  408  has a value of true that indicates the mobile terminal is authorized to originate and receive SMS messages. Various other service fields may, and typically are, included in HLR  400  that each specify any one or more of various subscription services, such as call waiting, call forwarding, and the like. 
     A GPRS_Settings field  410  may specify whether the mobile terminal has a GPRS subscription and settings thereof. For instance, GPRS_Settings field  410  may have a false setting or have another indicator that specifies the mobile terminal associated with HLR record  400  does not have a valid GPRS subscription. In the event that the mobile terminal has a GPRS subscription, GPRS_Settings field  410  may specify a service class. In the illustrative example, GPRS_Settings field  410  specifies that the associated mobile terminal has a GPRS subscription with a service setting of “Class_10”. 
     VLR_ID field  412  may specify the current VLR servicing the mobile terminal associated with HLR record  400 . In the present example, VLR_ID field  412  indicates the mobile terminal is being serviced by a VLR having an ID of VLR 1 . In a similar manner, SGSN_ID field  414  may specify the current SGSN servicing the mobile terminal associated with HLR record  400 . In the present example, SGSN_ID field  414  indicates the mobile terminal is being serviced by an SGSN having an ID of SGSN 1 . 
     An Short Message Service-Customized Applications for Mobile networks Enhanced Logic (CAMEL) Subscription Information (SMS-CSI) field  416  may contain trigger information required to invoke CAMEL Service Logic for Mobile Originating Short Message Submissions. In the illustrative example, the trigger information maintained in SMS-CSI field  416  is diagrammatically represented as “trigger_info”. A short message service center (SMSC) Number field  418  may include an identifier, e.g., an SS7 point code, assigned to an SMSC that is to service the associated subscriber. In the illustrative example, SMSC_Number field  418  has a value of Point Code c  assigned to SMSC  144  depicted in  FIGS.  1  and  2   . An MSC_ID field  420  may include an identifier, e.g., a point code, of the MSC currently, or most recently, servicing the mobile terminal associated with HLR record  400 . In the present example, the point code of the MSC specified by MSC_ID field is represented as “Point Code x ”. 
     To facilitate provisioning of one number service, the HLR may additionally include a “dummy” profile assigned to a land-line telephony device to facilitate one number voice and data services.  FIG.  4 B  is a diagrammatic representation of an exemplary HLR record  450  that may be associated with a particular enterprise user that facilitates one number voice and data services. HLR dummy record  450  is assigned to a land-line telephony device assigned to an enterprise subscriber and is distinct from an HLR record assigned to the subscriber&#39;s mobile terminal. In the illustrative example, HLR record  450  is allocated for Party A that is a member of the enterprise network and is associated with Party A&#39;s enterprise land-line telephony device  154  depicted in  FIGS.  1  and  2   . HLR record  450  may include an IMSI field  452  that may be nulled or assigned an identifier that indicates that no IMSI is associated with the telephony device for which HLR record  450  is allocated. An MSISDN field  454  may have a land-line number assigned thereto for associating dummy HLR record  450  with a land-line telephony device. In the present example, MSISDN field  454  has a value of 19725552001, that is the enterprise directory number of the land-line device  154  assigned to Party A in  FIGS.  1  and  2   . HLR record  450  may include various service fields that indicate validity, invalidity, or other subscription characteristics of various services. In the present dummy HLR record  450  includes a Voice field  456  having a value false (F) that indicates voice services are not to be prescribed via the cellular network for the telephony device associated with dummy record  450 . An SMS field  458 , on the other hand, indicates SMS services are authorized for the telephony device for which dummy HLR record  450  is allocated. Thus, in the present example, HLR record  450  indicates SMS services are authorized for the telephony device specified by MSISDN field  454 . Various fields  460 - 468  may be nulled. An MSC_ID field  470  may be assigned a value to redirect services associated with HLR dummy record  450  to an enterprise entity in accordance with an embodiment. In the present example, MSC_ID field  470  is assigned Point Code A —the SS7 point code of GS-C  180  such that signaling normally directed to a MSC is instead directed to the GS-C that services the enterprise network of the land-line telephony device for which dummy HLR record  450  is allocated. In accordance with embodiments, SMS messages directed to the telephony device specified by MSISDN field  454  are ultimately routed to a cellular telephony device associated with HLR record  450  as will be described more fully hereinbelow. 
       FIG.  5    is a simplified diagrammatic representation of an exemplary SMS message  500  format implemented in accordance with an embodiment. SMS message  500  may include a Sender_Num field  502  that includes the MSISDN of a mobile terminal that originates SMS message  500 . Likewise, SMS message  500  may include a Destination_Num field  504  that includes the MSISDN of the destination mobile terminal to which SMS message  500  is directed. Alternatively, the Destination_Num field may be included in a header or may be included in fields or subfields included in SMS message  500  that are not depicted. A message field  506  may include the SMS message content. Various other fields, such as fields that specify the length of SMSC information, type of SMSC address, service center number, data coding scheme, timestamp, and various other information, may, and typically are, included in SMS message  500  as is understood. The depicted representation of SMS message  500  is simplified to facilitate an understanding of embodiments disclosed herein. 
     In accordance with embodiments, the phone numbers specified by Sender_Num field may be changed in transit of SMS message  500  to facilitate one number servicing of multiple telephony devices. For instance, for a subscriber that is to be provided with one number servicing, the subscriber may originate an SMS message from a mobile terminal assigned to the subscriber, and the sender number of the Sender_Num field  502  may be replaced with a land-line enterprise directory number of a land-line telephony device assigned to the user prior to delivery of the SMS message to the destination device. In this manner, the user receiving the SMS message is presented with the land-line phone number of the originator in the SMS message. In a similar manner, when an SMS message is directed towards a user that is provided with one number servicing, an enterprise directory number of a land-line telephone assigned to the user may be entered by an originating party as the destination number to which the SMS message is directed. The destination number comprising a land-line phone number may be changed in transit of the SMS message to a MSISDN number assigned to the destination user such that the SMS message is routed to the mobile terminal of the destination user. In this manner, a person originating an SMS message to a destination user that is provided with one number servicing need only be aware of the destination user&#39;s land-line enterprise directory number. 
       FIG.  6 A  is a diagrammatic representation depicting a signaling flow  600  of an SMS transmission in a network generally configured as depicted and described with reference to  FIG.  2    from a mobile terminal user to another mobile terminal user implementing one number servicing in accordance with an embodiment. The network may include cellular networks  110  and  111  and an enterprise network  150 . In an embodiment, one number servicing functionality provided in the system depicted in  FIG.  6 A  may be implemented using CAMEL Phase 3 triggers for Short Message Service, although other trigger mechanisms may be suitably substituted therefor. 
     In the following example, assume Party A and Party B are mobile subscribers that are members of an Enterprise hosting enterprise network  150  and that are assigned respective mobile terminals  140  and  141 . Party A&#39;s mobile number is +1-972-444-1001, and Party A&#39;s office number for land-line telephony device  154  deployed in enterprise network  150  is +1 972-555-2001. Further assume Party A&#39;s short code, or office extension, is 2001. Party B&#39;s mobile terminal  141  number is +1-972-444-1002, Party B&#39;s office number for land-line telephony device  155  deployed in enterprise network  150  is +1-972-555-2002, and Party B&#39;s short code is 2002. 
     In a first example, Party A desires to send a SMS message to Party B. Party A can address the SMS message to either Party B&#39;s mobile number, office number, or short code. For purposes of illustration, assume Party A enters Party B&#39;s office number as the SMS destination number. Accordingly, an SMS message  610  is generated at mobile terminal  140  as generally depicted in  FIG.  6 B . SMS message  610  may include a Sender_Num field  612  assigned the MSISDN of mobile terminal  140 , a Destination_Num field  614  assigned the enterprise directory number of Party B&#39;s land-line telephony device  155 , and the SMS message content (illustratively designated “Message 1 ”) in a Message field  616  as depicted in  FIG.  6 B . When Party B receives the SMS message, the originator&#39;s address will display as Party A&#39;s office number or short code in accordance with one number servicing implemented in accordance with an embodiment. 
     SMS message  610  as depicted in  FIG.  6 B  is entered at mobile terminal  140  and is sent from Party A&#39;s mobile terminal  140  to a serving MSC  122  (step  650 ). MSC  122  includes or interfaces with a VLR  124  that has previously downloaded Party A&#39;s subscriber profile from the HLR to which Party A&#39;s mobile terminal  140  is registered as is understood. As the network supports CAMEL Phase 3, the Short Message Service CAMEL Subscription Information (SMS-CSI) is transferred to VLR  124 . The SMS-CSI contains trigger information which is required to invoke CAMEL Service Logic for Mobile Originating Short Message submissions. In this case, MSC  122  will trigger to GS-C  180  which will act as the SMSC (step  651 ). 
     After the trigger is launched to the GS-C  180 , GS-C  180  identifies the enterprise to which Party A belongs, and subsequently sends SMS message  610  to corresponding GS-E  182  (step  652 ). GS-E  182  verifies if the destination address of SMS message  610  is a member of Enterprise X by interrogating an Enterprise Member profile database  190 . Enterprise Member profile database  190  may include records or profiles for respective enterprise members that associate a land-line number of an enterprise telephony device assigned to a particular enterprise member with a MSISDN number of a mobile terminal assigned to the enterprise member as described with reference to  FIG.  2   . In the present example, Party A has entered Party B&#39;s land-line number as the destination number of SMS message  610 . Interrogation of profile database  190  with Party B&#39;s land-line number results in selection of a record  190   b  allocated for Party B that indicates the destination number is Party B&#39;s land-line and provides the MSISDN of Party B&#39;s mobile terminal  141  to GS-E  182 . GS-E  182  may then modify the destination address of SMS message  610  to be the corresponding mobile number of Party B as depicted by SMS message  610  in  FIG.  6 C  having a Destination_Num field  614  with the MSISDN of mobile terminal  141 . This enables the message to be routed through the mobile network to the destination party. 
     In addition, the GS-E  182  retrieves the member record  190   a  assigned to Party A by interrogating Enterprise Member profile database  190  with Party A&#39;s mobile terminal number retrieved from Sender_Num field  612  of SMS message  610 . Party A&#39;s member record  910   a  includes Party A&#39;s land-line number in association with Party A&#39;s mobile terminal MSISDN or directory number. Accordingly, GS-E  182  may modify the source address to be Party A&#39;s office number or short code in place of Party A&#39;s mobile number such that the recipient will receive the SMS with Party A&#39;s office number as the originator as depicted by Sender_Num field  612  of SMS message  610  in  FIG.  6 C . 
     In accordance with another embodiment, GS-E  182  may, upon determining the destination subscriber is a member of Enterprise X, invoke an enterprise messaging service, such as a corporate Instant Messaging service, for delivery of SMS message  610 . For example, the member record for Party B retrieved from member database  190  may indicate that SMS messages are to be additionally delivered to Party B via an Instant Messaging service. Assuming the SMS message is to be additionally delivered to Party B via an Instant Messaging service, GS-E  182  may convert the SMS message to an Instant Message and send the IM to an Enterprise IM server  192  (step  654 ). The IM may then be forwarded to Party B, e.g., to Party B&#39;s enterprise desktop  153  (step  655 ). In addition, GS-E  182  may record the transaction as part of Party A&#39;s logs within the enterprise. 
     Delivery of SMS message  610  to Party B&#39;s mobile terminal  141  may continue with GS-E  182  responding to GS-C  180  (step  656 ), which in turn responds to the MSC  122  trigger with the instructions to route the message to SMSC  144  for delivery (step  657 ). MSC  122 , in turn, forwards the SMS message to SMSC  144  for delivery to Party B (step  658 ). SMSC  144  then queries HLR  126  to determine the serving MSC  123  of the recipient based on the recipient&#39;s mobile number (step  659 ). HLR  126  responds to SMSC  144  with the serving MSC of the recipient (step  660 ). SMSC  144  will then deliver the message with the modifications made by GS-E  182  to MSC  123  (step  661 ) which delivers the SMS to mobile terminal  141  via an appropriate base station sub-system (step  662 ). The source address will be Party A&#39;s office number or short code, and the destination address will be Party B&#39;s mobile number as depicted in  FIG.  6 C . 
       FIG.  7 A  is a diagrammatic representation depicting a signaling flow  700  of an SMS transmission in a network generally configured as depicted and described with reference to  FIG.  2    from a mobile terminal user to another mobile terminal user implementing one number servicing in accordance with an embodiment. The network may include cellular networks  110  and  111  and an enterprise network  150 . 
     As in the example depicted in  FIG.  6 A , Party A desires to send an SMS message to Party B, and for purposes of illustration assume Party A enters Party B&#39;s office number as the SMS destination number. Accordingly, an SMS message  710  is generated at mobile terminal  140  as generally depicted in  FIG.  7 B . SMS message  710  may include a Sender_Num field  712  assigned the MSISDN of mobile terminal  140 , a Destination_Num field  714  assigned the enterprise directory number of Party B&#39;s land-line telephony device  155 , and the SMS message content (illustratively designated “Message 2 ”) in a Message field  716  as depicted in  FIG.  7 B . 
     In the present example, however, assume the network does not support CAMEL Phase 3 triggers. Instead, a Transparent Router  770  is placed in front of SMSC  144  and monitors the link for SMS messages originated by subscribers of the enterprise service. Subscriber A may originate SMS message  710  addressed to Subscriber B (step  750 ) that is transmitted to serving MSC  122  which attempts to forward the SMS to SMSC  144  (step  751 ). However, transparent router  770  detects the SMS message and evaluates whether the originator subscribes to the enterprise service. If the originator is not subscribed to the enterprise service, transparent router  770  may allow the message to pass through unmodified. Assuming Subscriber A is subscribed to the enterprise service, transparent router  770  intercepts the message and re-routes it to GS-C  180  (step  752 ) which forward SMS message  710  to GS-E  182  (step  753 ). GS-E  182  verifies if the destination address of the SMS message is a member of Enterprise X by interrogating an Enterprise Member profile database  190 . In the present example, Party B, the destination party, is a member of Enterprise X. Assume Party A entered Party B&#39;s land-line number as the destination number of the SMS message. Interrogation of profile database  190  with Party B&#39;s land-line number results in selection of record  190   b  that indicates the destination number is Party B&#39;s land-line and provides the MSISDN of Party B&#39;s mobile terminal  141  to GS-E  182 . GS-E  182  may then modify the destination address of the SMS message to be the corresponding mobile number of Party B as depicted by Destination_Num field  714  of SMS message  710  in  FIG.  7 C . This enables the message to be routed through the mobile network to the destination party. 
     In addition, GS-E  182  retrieves member record  190   a  assigned to Party A which includes Party A&#39;s land-line number. Accordingly, GS-E  182  may modify the source address to be Party A&#39;s office number or short code in place of Party A&#39;s mobile number such that the recipient will receive the SMS with Party A&#39;s office number as the originator as depicted by Sender_Num field  712  in  FIG.  7 C . 
     In accordance with another embodiment, GS-E  182  may, upon determining the destination subscriber is a member of Enterprise X, invoke an enterprise messaging service, such as a corporate Instant Messaging service, for delivery of the SMS message. For example, member record  190   b  for Party B retrieved from member database  190  may indicate that SMS messages are to be additionally delivered to Party B via an Instant Messaging service. Assuming the SMS message is to be additionally delivered to Party B via an Instant Messaging service, GS-E  182  may convert the SMS to an Instant Message and send the IM to an Enterprise IM server  192  (step  754 ). The IM may then be forwarded to Party B, e.g., to Party B&#39;s enterprise desktop  153  (step  755 ). In addition, GS-E  182  may record the transaction as part of Party A&#39;s logs within the enterprise. 
     Delivery of the SMS message to Party B&#39;s mobile terminal  141  may continue with GS-E  182  responding to GS-C  180  by returning the SMS message to be re-injected to GS-C  180  (step  756 ) with the modifications performed by GS-E  182  as depicted in  FIG.  7 C  which forwards the SMS message to transparent router  770  (step  757 ). Transparent router  770 , in turn, forwards the SMS message to SMSC  144  (step  758 ). SMSC  144  then queries HLR  126  to determine the serving MSC  123  of the recipient based on the recipient&#39;s mobile number (step  759 ). HLR  126  responds to SMSC  144  with the serving MSC  123  of the recipient (step  760 ). SMSC  144  will then deliver the message with the modifications made by GS-E  182  to MSC  123  (step  761 ) which delivers the SMS to mobile terminal  141  via an appropriate base station sub-system (step  762 ). The source address will be Party A&#39;s office number or short code, and the destination address will be Party B&#39;s mobile number as depicted in  FIG.  7 C . 
       FIG.  8 A  is a diagrammatic representation depicting a signaling flow  800  of an SMS transmission in a network  100  generally configured as depicted and described with reference to  FIG.  2    from a mobile terminal user to another mobile terminal user implementing one number servicing in accordance with an embodiment. The network may include cellular networks  110  and  111  and an enterprise network  150 . 
     As in the example depicted in  FIG.  7 A , Party A desires to send a SMS message to Party B, and for purposes of illustration assume Party A enters Party B&#39;s office number as the SMS destination number. Accordingly, an SMS message  810  is generated at mobile terminal  140  as generally depicted in  FIG.  8 B . SMS message  810  may include a Sender_Num field  812  assigned the MSISDN of mobile terminal  140 , a Destination_Num field  814  assigned the enterprise directory number of Party B&#39;s land-line telephony device  155 , and the SMS message content (illustratively designated “Message 3 ”) in a Message field  816  as depicted in  FIG.  8 B . 
     In the present example, however, a Transparent Router  870  is used only to intercept and re-route short messages originated by subscribers of the enterprise service, but is not used to re-inject the message once processed by the GS-E. 
     Subscriber A may originate SMS message  810  addressed to Subscriber B (step  850 ) that is transmitted to serving MSC  122  which attempts to forward the SMS to SMSC  144  (step  851 ). However, transparent router  870  detects SMS message  810  and evaluates whether the originator subscribes to the enterprise service. If the originator is not subscribed to the enterprise service, transparent router  870  may allow the message to pass through unmodified. Assuming Subscriber A is subscribed to the enterprise service, transparent router  870  intercepts the message and re-routes it to GS-C  180  (step  852 ) which forwards SMS message  810  to GS-E  182  (step  853 ). GS-E  182  verifies the destination address of SMS message  810  is a member of Enterprise X by interrogating Enterprise Member profile database  190 . In the present example, Party B, the destination party, is a member of Enterprise X. Assume Party A entered Party B&#39;s land-line number as the destination number of SMS message  810 . Interrogation of profile database  190  results in selection of record  190   b  that indicates the destination number is Party B&#39;s land-line number and provides the MSISDN of Party B&#39;s mobile terminal  141  to GS-E  182 . GS-E  182  may then modify the destination address of the SMS message to be the corresponding mobile number of Party B as depicted by Destination_Num field  814  in  FIG.  8 C . This enables the message to be routed through the mobile network to the destination party. 
     In addition, GS-E  182  retrieves member record  190   a  assigned to Party A which includes Party A&#39;s land-line number. Accordingly, GS-E  182  may modify the source address to be Party A&#39;s office number or short code in place of Party A&#39;s mobile number such that the recipient will receive the SMS message with Party A&#39;s office number as the originator as depicted by the Sender_Num field  812  in  FIG.  8 C . 
     In accordance with another embodiment, GS-E  182  may, upon determining the destination subscriber is a member of Enterprise X, invoke an enterprise message service, such as a corporate Instant Messaging service, for delivery of the SMS message. For example, member record  190   b  for Party B retrieved from member database  190  may indicate that SMS messages are to be additionally delivered to Party B via an Instant Messaging service. Assuming the SMS message is to be additionally delivered to Party B via an Instant Messaging service, GS-E  182  may convert the SMS to an Instant Message and send the IM to an Enterprise IM server  192  (step  854 ). The IM may then be forwarded to Party B, e.g., to Party B&#39;s enterprise desktop  153  (step  855 ). In addition, GS-E  182  may record the transaction as part of Party A&#39;s logs within the enterprise. 
     Delivery of SMS message  810  to Party B&#39;s mobile terminal  141  may continue with GS-E  182  responding to GS-C  180  by returning SMS message  810  to be re-injected to GS-C  180  (step  856 ) with the modifications performed by GS-E  182  as depicted by SMS message  810  in  FIG.  8 C . GS-C  180  may then forward the SMS message to SMSC  144  (step  857 ), rather than the transparent router as performed in the configuration depicted in  FIG.  7 A , with the modified information. In this instance, GS-C  180  is adapted to handle any response from SMSC  144  resulting from transmission of the SMS message thereto. SMSC  144  then queries HLR  126  to determine the serving MSC  123  of the recipient based on the recipient&#39;s mobile number (step  858 ). HLR  126  responds to SMSC  144  with the serving MSC of the recipient (step  859 ). SMSC  144  will then deliver the message with the modifications made by GS-E  182  to MSC  123  (step  860 ) which delivers the SMS to mobile terminal  141  via an appropriate base station sub-system (step  861 ). The source address will be Party A&#39;s office number or short code, and the destination address will be Party B&#39;s mobile number as depicted in  FIG.  8 C . 
       FIG.  9 A  is a diagrammatic representation depicting a signaling flow  900  of an SMS transmission in a network system from a mobile terminal user to another mobile terminal user implementing one number servicing in accordance with an embodiment. The network system may include cellular networks  110  and  111  and an enterprise network  150 . 
     In the following example, assume Party C and Party A are mobile subscribers, Party C is not a member of the Enterprise hosting enterprise network  150 , and that Party A is a member of the Enterprise hosting enterprise network  150 . Further assume Party C and Party A are assigned respective mobile terminals  142  and  140 . Party A&#39;s mobile number is +1-972-444-1001, Party A&#39;s office number is +1 972-555-2001, and Party A&#39;s short code is 2001. Party C&#39;s mobile number is +1-214-777-7777. 
     The non-enterprise subscriber may originate an SMS to the office number of the enterprise user at mobile terminal  142 . Accordingly, an SMS message  910  is generated at mobile terminal  142  as generally depicted in  FIG.  9 B . SMS message  910  may include a Sender_Num field  912  assigned the MSISDN of mobile terminal  142 , a Destination_Num field  914  assigned the enterprise directory number of Party A&#39;s land-line telephony device  154 , and the SMS message content (illustratively designated “Message 4 ”) in a Message field  916  as depicted in  FIG.  9 B . The SMS message is sent from mobile terminal  142  to servicing MSC  122  (step  950 ). MSC  122  includes or interfaces with a VLR  124  that has previously downloaded Party C&#39;s subscriber profile from the HLR to which Party C&#39;s mobile terminal  142  is registered as is understood. In this case, MSC  122  identifies SMSC  144  as the servicing SMSC and forwards the SMS message thereto (step  951 .) 
     SMSC  144  may then query HLR  126  based on the office number entered by Party C as the destination to identify the serving MSC (step  952 ). Prior to this, HLR  126  will have been provisioned with a standalone, or dummy, subscriber profile for the enterprise user&#39;s office number similar to dummy HLR record  450  depicted and described with reference to  FIG.  4 B . Dummy record  450  will indicate Party A associated with the destination office number has SMS service. In addition, prior to these events, GS-C  180  will register with HLR  126  as the serving MSC of the enterprise subscriber in the HLR dummy profile associated with the office number. For instance, assume dummy HLR record  450  depicted in  FIG.  4 B  is allocated for Subscriber A&#39;s land-line office telephony device  154 . In this instance, GS-C  180  may be registered as the serving MSC of the land-line telephony device assigned to Party A by assigning the point code (illustratively designated Point Code A ) of GS-C  180  to the MSC_ID field  440  of dummy HLR record  450 . The HLR profile associated with the enterprise subscriber&#39;s office number will be supported throughout mobile networks such that any MSC can query the HLR for the profile. Note that this HLR profile is entirely separate from the existing HLR profile associated with the enterprise subscriber&#39;s mobile number, i.e., HLR record  400 . The handling of voice calls to the office number from mobile networks will be described in a subsequent section. 
     HLR  126  responds with the serving MSC being the GS-C  180  which had previously registered as the serving MSC (step  953 ). SMSC  144  may then send the SMS message to GS-C  180  accordingly (step  954 ). GS-C  180  identifies the enterprise to which the destination number (Subscriber A&#39;s land-line office number) belongs and routes SMS message  910  to corresponding GS-E  182  (step  955 ). GS-E  182  may modify the destination number to be the mobile number of the enterprise user, that is to the mobile number of mobile terminal  140 , in order to enable the message to be routed through the mobile network as depicted by Destination_Num field  914  in  FIG.  9 C . 
     In accordance with another embodiment, GS-E  182 , upon determining the destination subscriber is a member of Enterprise X, may invoke an enterprise message service, such as a corporate Instant Messaging service, for delivery of the SMS message. For example, the member record  190   a  for Party A retrieved from member database  190  may indicate that SMS messages are to be additionally delivered to Party A via an Instant Messaging service. Assuming the SMS message is to be additionally delivered to Party A via an Instant Messaging service, GS-E  182  may convert the SMS to an Instant Message and send the IM to an Enterprise IM server  192  (step  956 ). The IM may then be forwarded to Party A, e.g., to Party A&#39;s enterprise desktop  152  (step  957 ). In addition, GS-E  182  may record the transaction as part of Party A&#39;s logs within the enterprise. 
     Delivery of the SMS message to Party A&#39;s mobile terminal  140  may continue by GS-E  182  responding to GS-C  180  with the SMS message having the modified destination information (step  958 ). GS-C  180  may then originate an SMS message to SMSC  144  with the modified destination information as depicted in  FIG.  9 C  (step  959 ). 
     SMSC  144  may then query HLR  126  based on the destination mobile number (step  960 ), and HLR  126  may respond with the serving MSC  123  of the enterprise user&#39;s mobile terminal  140  (step  961 ). SMSC  144  may then deliver the SMS message to MSC  123  and to the destination mobile terminal  140  (step  962 ). 
       FIG.  10    is a diagrammatic representation depicting a signaling flow  1000  for handling of mobile originations for voice calls to an enterprise number which is provisioned in a mobile network HLR in accordance with an embodiment. This implementation enables voice calls originated in the mobile network to be routed out to the public land-line network in order to reach the office number destination in the land-line network. 
     In the following example, assume Party C is a mobile subscriber, and that Party A is a member of the Enterprise hosting enterprise network  150 . Further assume Party C is assigned mobile terminal  142 , and Party A is assigned office land-line telephony device  154 . In this instance, assume Party A has a dummy HLR record similar to dummy HLR record  450  allocated in the HLR for land-line telephony device  154  to facilitate delivery (to Party A&#39;s mobile terminal  140 ) of SMS messages submitted with the enterprise directory number of device  154  as the destination number as described above. 
     A call may be originated by Party C at mobile terminal  142  to the office number of device  154  assigned to Party A (step  1050 ). As noted above, Party A has a profile in HLR  126  for the office number of device  154  for the purpose of enabling SMS messages submitted with the office number as the destination number. 
     MSC  122 , on receipt of the call setup request, queries HLR  126  for a routing number to the serving MSC in order to deliver the call to the recipient (step  1051 ). HLR queries GS-C  180  that has previously registered as the serving MSC for the office number (step  1052 ). GS-C  180  is responsible for maintaining the periodic registrations such that the HLR profile continuously points to GS-C  180  as the serving MSC. 
     GS-C  180  identifies the enterprise network associated with the office number destination and sends the message to the corresponding GS-E (step  1053 ). GS-E  182  sets the routing number to be returned to the originating MSC to be the office number on the public network. GS-E  182  may also communicate with another enterprise messaging service (step  1054 ) to convey an incoming call to a user terminal (step  1055 ). In addition, GS-E  182  may record the transaction as part of Party A&#39;s logs within the enterprise. 
     GS-E  182  may then respond to GS-C  180  (step  1056 ) which in turn responds to HLR  126  (step  1057 ). HLR  126  then may respond to serving MSC  122  with the routing number to the serving MSC set to the office number on the public land-line network (step  1058 ). 
     With this information, originating MSC  122  routes the call to the routing number. The call is routed out to the public network  1065  to the office number which could be in the enterprise PBX  158  (step  1059 ). In this case, enterprise PBX  158  may route the call to the office number of telephony device  154  assigned to the subscriber (step  1060 ). 
       FIG.  11    is a flowchart of exemplary SMS message processing as may be implemented by an enterprise gateway server that facilitates one number service in accordance with an embodiment. The SMS message processing routine is invoked (step  1102 ), and the gateway server awaits receipt of an SMS message (step  1104 ). On receipt of an SMS message, the sender number and the destination number may be read from the SMS message (step  1106 ), e.g., from respective sender number and destination number fields  502  and  504 . An evaluation may then be made to determine if the destination is assigned to an enterprise member (step  1108 ), e.g., by interrogation of enterprise member database  190  with the destination number read from the SMS message. In the event that the destination number is not assigned to an enterprise member, the SMS message processing routine may proceed to evaluate whether the sender number is assigned to an enterprise member (step  1114 ). 
     Returning again to step  1108 , in the event that the destination number is evaluated as being assigned to an enterprise member, an evaluation may then be made to determine if the destination number is a land-line number assigned to the destination party (step  1110 ). In the event that the destination number is evaluated as comprising a land-line number, the processing routine may proceed to evaluate the sender number according to step  1114 . In the event that the destination number is evaluated as a land-line number of a telephony device assigned to the destination party, the destination number of the SMS message may be replaced with the mobile, or MSISDN, number of the mobile terminal assigned to the destination party (step  1112 ). The SMS message processing routine may then continue to step  1114  to evaluate the sender number of the SMS message. 
     In the event that the sender number is not determined to be assigned to an enterprise member at step  1114 , the SMS message processing routine may proceed to continue with routing of the SMS message (step  1120 ). Alternatively, if the sender number is determined to be assigned to an enterprise member at step  1114 , the SMS processing routine may then evaluate whether the sender number is a mobile number of the mobile terminal assigned to the sending party (step  1116 ). In the event that the sender number is not evaluated as comprising a mobile number, the SMS message may be routed according to step  1120 . If, however, the sender number is evaluated as comprising a mobile number of a mobile terminal assigned to the sending party, the sender number may be replaced with the land-line number assigned to the sending party (step  1118 ), and the gateway server may then continue with routing of the SMS message according to step  1120 . The SMS message processing routine cycle may then end (step  1122 ). 
       FIG.  12    is a diagrammatic representation depicting a signaling flow  1200  for handling of mobile originations for voice calls to an enterprise number which is provisioned in a mobile network HLR in accordance with an embodiment. This implementation enables voice calls originated in the mobile network to an enterprise number be automatically re-routed based on criteria in the GS-C and/or GS-E to the corresponding mobile number in the mobile network in order to reach the mobile subscriber associated with the enterprise number. As an example, this function may be used in an emergency situation when landline network connections to the enterprise are inoperable. In this case the GS-C and/or GS-E may be placed in an emergency routing mode such that mobile originated calls to enterprise numbers will instead be routed to their mobile devices. 
     In the following example, assume Party C is a mobile subscriber, and that Party A is a member of the Enterprise hosting enterprise network  150 . Further assume Party C is assigned mobile terminal  142 , and Party A is assigned office land line telephony device  154 . In this instance, assume Party A has a dummy HLR record similar to dummy HLR record  450  allocated in HLR  126  for land line telephony device  154  to facilitate delivery (to Party A&#39;s mobile terminal  140 ) of SMS messages submitted with the enterprise directory number of device  154  as the destination number. 
     A call may be originated by Party C at mobile terminal  142  to the office number of device  154  assigned to Party A (step  1250 ). As noted above, Party A has a profile in HLR  126  for the office number of device  154  for the purpose of enabling SMS messages submitted with the office number as the destination number. 
     MSC  122 , on receipt of the call setup request, queries HLR  126  for a routing number to the serving MSC in order to deliver the call to the recipient (step  1252 ). HLR queries GS-C  180  that has previously registered as the serving MSC for the office number (step  1254 ). GS-C  180  is responsible for maintaining the periodic registrations such that the HLR profile continuously points to GS-C  180  as the serving MSC. 
     GS-C  180  identifies the enterprise network associated with the office number destination and sends the message to the corresponding GS-E  182  (step  1256 ). 
     GS-E  182  sets the routing number to be returned to the originating MSC to be the corresponding mobile number of enterprise user Party A. Note that if GS-E  182  is not available, GS-C  180  may set the routing number to be returned to the originating MSC  122  to be the corresponding mobile number of the enterprise user Party A. 
     GS-E  182  may also communicate with another enterprise messaging service (step  1258 ) to convey an incoming call to user terminal  152  (step  1260 ). In addition, GS-E  182  may record the transaction as part of Party A&#39;s logs within the enterprise. 
     GS-E  182  may then respond to GS-C  180  (step  1262 ) which in turn responds to HLR  126  (step  1264 ). HLR  126  then may respond to serving MSC  122  with the routing number to the serving MSC set to the mobile number to be routed out to the public landline network (step  1266 ). If both Party C and Party A are subscribers on the same mobile operator network, the call would instead be routed directly from the MSC serving Party C to the GMSC in the same network of which Party A is a subscriber. Otherwise the call is routed out to the public network as described below. 
     The call is then routed via the public network (step  1268 ) to the Gateway MSC (GMSC)  124  of the network to which the mobile subscriber subscribes (step  1270 ). GMSC  124  responds to PSTN  1165  (step  1272 ) which in turn responds to MSC  122  (step  1274 ) after which the originating call leg is through-connected from the Party C, i.e., mobile terminal  142 , to the GMSC  124 . 
     GMSC  124  then queries HLR  126  (step  1276 ) to obtain a routing to the serving MSC of Party A. HLR  126  requests a routing number from serving MSC  123  (step  1278 ) which is returned to HLR  126  (step  1280 ). HLR  126  returns the routing number to GMSC  123  (step  1282 ). GMSC  123  then routes the call to the routing number over the public landline network  1165  (step  1284 ) to serving MSC  123  (step  1286 ). Serving MSC  124  responds (step  1288 ) to the public landline network  1165  which in turn responds to GMSC  124  (step  1290 ). The terminating call leg is through-connected to the serving MSC (step  1292 ). 
     As described, embodiments disclosed herein provide mechanisms for enabling the use of an alternative numbering plan for delivering short messages to mobile subscribers. Enterprise members or other users subscribed to a one number service may send short messages destined to members of an enterprise or closed network from their mobile or other devices associated with their subscription using an alternative enterprise directory number. The alternative enterprise directory number may comprise an office number of a land-line telephony device. The alternative enterprise directory number, rather than the mobile number, will be presented at the destination device as the originating number. The recipient can respond to the message by addressing the response to the enterprise or closed network number, and the SMS message will be delivered to the originator&#39;s mobile or other devices associated with their subscription. 
     Although the specific network architecture and nomenclature are depicted and described according to the GSM, it is understood that this is done so for illustrative purposes only and that the network architecture on which embodiments disclosed herein may be applied is not limited to any particular standard, but rather may be equivalently implemented on any other communications system supporting any variety of cellular communication systems, e.g. D-AMPS, GSM, CDMA, IS-41, ANSI-41, UMTS, etc. 
     The flowchart of  FIG.  11    depicts process serialization to facilitate an understanding of disclosed embodiments and is not necessarily indicative of the serialization of the operations being performed. In various embodiments, the processing steps described in  FIG.  11    may be performed in varying order, and one or more depicted steps may be performed in parallel with other steps. Additionally, execution of some processing steps of  FIG.  11    may be excluded without departing from embodiments disclosed herein. 
     The illustrative block diagrams and flowcharts depict process steps or blocks that may represent modules, segments, or portions of code that include one or more executable instructions for implementing specific logical functions or steps in the process. Although the particular examples illustrate specific process steps or procedures, many alternative implementations are possible and may be made by simple design choice. Some process steps may be executed in different order from the specific description herein based on, for example, considerations of function, purpose, conformance to standard, legacy structure, user interface design, and the like. 
     Aspects of the present invention may be implemented in software, hardware, firmware, or a combination thereof. The various elements of the system, either individually or in combination, may be implemented as a computer program product tangibly embodied in a machine-readable storage device for execution by a processing unit. Various steps of embodiments of the invention may be performed by a computer processor executing a program tangibly embodied on a computer-readable medium to perform functions by operating on input and generating output. The computer-readable medium may be, for example, a memory, a transportable medium such as a compact disk, a floppy disk, or a diskette, such that a computer program embodying the aspects of the present invention can be loaded onto a computer. The computer program is not limited to any particular embodiment, and may, for example, be implemented in an operating system, application program, foreground or background process, driver, network stack, or any combination thereof, executing on a single computer processor or multiple computer processors. Additionally, various steps of embodiments of the invention may provide one or more data structures generated, produced, received, or otherwise implemented on a computer-readable medium, such as a memory. 
     Although embodiments of the present disclosure have been described in detail, those skilled in the art should understand that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure.