The mobile telephone industry has been associated with tremendous growth over the last several years. For instance, in the recent past, mobile telephones were costly, bulky and awkward to transport. Moreover, network coverage was not extensive enough to enable robust service. Only areas associated with dense population were provided with extensive wireless network coverage. In contrast, today's mobile phones (and other portable devices) have decreased in both size and cost and can be utilized as full-service computing machines. For example, many of the most recent and advanced mobile phones can be associated with word processing software, accounting software, and various other types of software. Network coverage has expanded to cover millions, if not billions, of users.
Advances in technology relating to mobile devices in general, and mobile phones in particular, continue to occur. For example, recently mobile telephones have been designed to communicate over disparate networks. For example, a dual mode handset can connect to a cellular network to effectuate communications between a user of the mobile phone and another phone device, and can further connect via WiFi to a wireless local access network (LAN) and thereafter utilize the Voice over Internet Protocol (VoIP) to effectuate communication between users. Use of VoIP is often desirable to users as it is associated with lower costs than employing a cellular network. In fact, some users may consider phone calls made over VoIP (or other IP-based network) completely free, despite the fact that they pay for Internet service.
Implementation of this dual mode service (DMS) is due at least in part to the Third Generation Partnership Project (3GPP), which have created specifications that define a mechanism that provides signal integrity for session initial protocol (SIP) signals between an IP multimedia subsystem (IMS) (P-SCCF) and user equipment (UE) (e.g., a mobile phone, a personal digital assistant, . . . ). This integrity prevents identity spoofing, man-in-the-middle attacks, and the like. The IMS represents a 3GPP and 3GPP2 effort to define an all-IP-based wireless network as a replacement for the various voice, data, signaling, and control network elements currently in existence. Furthermore, the IMS enables support for IP multimedia applications within the Universal Mobile Telecommunications System (UMTS). The UMTS is a 3G broadband packet-based transmission of text, digitized voice, video, and multimedia that offers a consistent set of services to mobile computer and phone users regardless of their physical location.
The telecom industry is currently shifting towards all IP-systems, thereby rendering dual mode service handsets an important tool (as they are compatible with existing cellular systems and emerging IP-systems). This shift is driven by desires to reduce costs and create new streams of revenue while protecting an operator business model. IMS is a new service domain that facilitates this shift by enabling convergence of data, speech, and network technology over an IP-based infrastructure. For users, IMS-based services enable transmittal and receipt of various data at significantly reduced cost, including voice, text, pictures, video, and/or any combination thereof in a highly personalized and secure manner. In summary, IMS is designed to bridge the gap between existing, traditional telecommunications technology and Internet technology that increased bandwidth does not provide.
As stated above, these emerging IP-based technologies have created demand for dual mode services, and thus for dual mode handsets. Using this technology, subscribers can employ WiFi to effectuate voice calls, transmission of data, and the like. In more detail, a subscriber can connect to a LAN by way of WiFi. Upon such connection, subscribers can employ services offered by their service provider.
As VoIP systems and dual mode handsets have become more accepted and prevalent, these systems have been required to provide the same capabilities as traditional telephone networks, including emergency services. During an emergency situation, a user can be flustered or injured and unable to provide accurate location information, whether due to age, infirmity, injury or ignorance. Typically, traditional fixed line telephone networks can connect a caller to local emergency services and automatically provide location information to the emergency service center. In the past, VoIP systems have not reliably provided location information or even connection to emergency services such as Enhanced 911 (E911). However, government regulations adopted by the Federal Communications Commission (FCC) now require VoIP providers to supply E911 service capabilities to their subscribers.