Abstract:
Indicator control for dual-mode phones. While under control of an enterprise Wi-Fi network, indicators on a dual-mode phone can be controlled using SIP messages. When operating in cellular mode, indicators on the dual-mode phone are controlled by SMS messages which are intercepted on arrival. A software agent connected to the enterprise SIP PBX and voicemail system receives messages for example indicating voicemail status which cause the software agent to send specially formatted SMS messages to the cellular phone and operate indicators.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is related to (1) U.S. patent application Ser. No. 11/955,104 filed on Dec. 12, 2007 and entitled “Single Number Presentation for Dual-Mode Phones” (Attorney docket no. 6259P041); (2) U.S. patent application Ser. No. 11/955,108 filed Dec. 12, 2007 and entitled “Delayed ACK in Dual-Mode Call Handover” (Attorney docket no. 6259P040); and (3) U.S. patent application Ser. No. 11/955,091 filed Dec. 12, 2007 and entitled “Single Voicemail for Dual-Mode Phones” (Attorney docket no. 6250P042), all incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to the operation of dual-mode phones, and more particularly, to handling indicators in dual-mode phones. 
         [0003]    Dual-mode phones support connections via Wi-Fi and cellular networks. While associated with the enterprise Wi-Fi network, the user places and receives calls through the enterprise Wi-Fi system. While out of range of the enterprise Wi-Fi network, the user places and receives calls through the cellular system. 
         [0004]    A problem arises however, as the enterprise provides a voicemail system to enterprise users, and the cellular system provides an additional voicemail system to its users. When in the range of the enterprise Wi-Fi system, the dual-mode phone user can receive indications of voicemail/fax/text through SIP Wi-Fi signaling to the dual-mode phone. But when connected to the cellular network, this signaling is not available. 
         [0005]    What is needed is a method of controlling the indicators in a dual-mode phone through the cellular network. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The invention may be best understood by referring to the following description and accompanying drawings that are used to illustrate embodiments of the invention in which: 
           [0007]      FIG. 1  shows a dual-mode phone in a network, and 
           [0008]      FIG. 2  shows a dual-mode phone. 
       
    
    
     DETAILED DESCRIPTION 
       [0009]    Embodiments of the invention relate to dual-mode phones, and to controlling indicators in dual-mode phones. In an embodiment of the invention, a dual-mode phone when operating in its cellular mode recognizes and interprets SMS messages to control indicators on the dual-mode phone. These SMS messages may be removed from the SMS log after processing. In the case of enterprise voicemail systems, a SIP back to back user agent (B2BUA) running in the enterprise environment subscribes to Message-Wait events generated by the PBX. When a message is left for the dual-mode phone user in the enterprise, the SIP PBX signals the agent, which generates and sends the proper SMS message to the cellular side of the dual-mode phone when it is outside of enterprise Wi-Fi range. 
         [0010]      FIG. 1 . shows an embodiment of the invention including a dual-mode phone. Enterprise SIP PBX communicates  210  with public switched telephone network (PSTN)  200 . SIP PBX  100  also supports voicemail system  110 . SIP PBX  100  also communicates with fixed mobility controller (FMC)  120 . Mobility controller  120  bridges the worlds of SIP PBX  100  and Wi-Fi network controller  130 . SIP PBX  100  and fixed mobility controller  120  communicate for example using protocols established by RFC 3261, RFC 2833, and RFC 3631, incorporated herein by reference. Voice streams are typically encoded using the RTP protocols defined by RFC 3550, incorporated herein by reference. 
         [0011]    As understood in the art, such a hardware platform as shown in  FIG. 1  for hosting mobility controller  120  includes a central processing unit (CPU)  122  connected to memory hierarchy  124 , and to one or more interfaces  126 . In one embodiment, CPU  122  is a MIPS-style CPU such as those from Raza Microelectronics or Cavium Networks, although CPUs from other companies such as Intel, AMD, Freescale, or the like may also be used. Memory hierarchy  124  includes read-only memory for system initialization, high-speed read-write memory such as DRAM, and bulk memory such as a hard disk or compact flash storage for files. Interfaces  126  include wired and wireless Ethernet interfaces as are known to the art. Controller  120  typically operates under the control of an operating system such as Linux, hosting software processes which provide device functionality. Additional hardware may be provided to provide for high-speed packet handling, crypto processing, and the like. While  FIG. 1  shows mobility controller  120  and Wi-Fi-network controller  130  as separate entities, it should be noted that they may also be software processes running on a shared hardware platform. As an example, a single hardware platform based on a multi-core MIPS processor such as those from Raza Microelectronics or Cavium Networks could host the functions of Wi-Fi network controller  130  along with mobility controller  120  and additional functions such as intrusion detection and/or firewalls. 
         [0012]    Dual-mode phone  300  has first radio subsystem  310  for Wi-Fi communications such as to Wi-Fi network controller  130 . Dual-mode phone  300  also has second radio subsystem  320  for communicating with cellular network  230  and through public switched telephone network  200 . As is common with many such devices, dual-mode phone  300  is a digital device operating under control of CPU  330  through programs and data stored in memory hierarchy  340 . Dual-mode phone  300  also has display  350  with indicators  352 ,  354 ,  356 . In one embodiment, display  350  is a liquid crystal display. Indicators  352 ,  354 ,  356  may be separate display elements such as light emitting diodes, or they may be fixed designs on liquid crystal display  350 , or may be areas on display  350  in which different symbols may be displayed such as by providing different bitmaps representing the symbol to be displayed as an indicator. Other aspects of dual-mode phone  300  such as speakers, microphones, power, keyboards and the like are understood by those in the art, and are not shown. 
         [0013]    In operation, when dual-mode phone  300  is in the range of enterprise Wi-Fi network controller  130 , indicators  352 ,  354 ,  356  may be controlled by SIP signaling over the Wi-Fi network as described in RFC 3842, incorporated herein by reference. As an example, mobility controller  120  contains a back to back user agent (B2BUA) software process which subscribes to message wait events produced by SIP PBX  100 . Messages from PBX  100  and voicemail system  110  may be communicated as SIP messages through network controller  130  to alert the user of events of interest, such as waiting voicemail, text messages, emails, or the like. Such SIP messages are transmitted over the Wi-Fi network to a user agent process operating in dual-mode phone  300 , and can activate and/or deactivate indicators  352 ,  354 ,  356 . 
         [0014]    Such indicators  352 ,  354 ,  356  in dual-mode phone  300  can also be used to indicate other conditions such as the presence of text or e-mail messages, or other conditions. 
         [0015]    According to an embodiment of the invention, when dual-mode phone  300  is not within the range of the enterprise Wi-Fi network, mobility controller  120  cannot use SIP or SIP-style messaging. Instead, mobility controller  120  produces a SMS message which is sent through SIP PBX  100  over public switched telephone network  200  to the cellular number associated with dual-mode phone  300 . In an alternate embodiment, e-mail messages may be used. 
         [0016]    When the SMS message is received through radio subsystem  320  by dual-mode phone  300 , agent  360  recognizes the SMS message, and takes appropriate action with respect to indicators  352 ,  354 ,  356 . 
         [0017]    Agent  360  on recognizing the SMS message may remove the SMS message from the queue after taking the appropriate action with respect to indicators  352 ,  354 ,  356 . In such an embodiment, the user of dual-mode phone  300  will not see such SMS messages. 
         [0018]    Appropriate SMS messages for agent  360  may be recognized by the message header, or by message contents, One SMS message may alter a single indicator, or multiple indicators. An SMS message may indicate that a fixed indicator is to be turned on, turned off, or flashed. In some embodiments, an SMS message may include data such as a bitmapped image for an icon to be displayed on screen  350 . 
         [0019]    SMS messages for agent  360  may be authenticated, for example to reduce transmission errors and/or spoofing. Such authentication may be accomplished, for example, by verifying the sender of the SMS message for agent  360  against one or more authorized senders. SMS messages for agent  360  may be authenticated using check digits, checksums, or digital signatures 
         [0020]    While the invention has been described in terms of various embodiments, the invention should not be limited to only those embodiments described, but can be practiced with modification and alteration within the spirit and scope of the appended claims. The description is this to be regarded as illustrative rather than limiting.