IE84950B1 - A roaming gateway - Google Patents

Abstract

ABSTRACT A roaming gateway has at least one [P network interface, and at least one cellular network interface, and inter-working functions for inter-working between a wireless IP network and a cellular network. The inter-working functions communicate with user devices in an IP network according to a machine-level subscribe—and—notify event package protocol for managing handover of mobile devices roaming between IP and cellular networks. They also poll a cellular network for subscriber status on that cellular network in the absence of a mobility event package. The inter—working functions comprise HSS functionality programmed to access data on a HLR of a cellular network and to perform HSS operations using said data. The gateway applies routing policies specific to call types, allowing or disallowing the anchoring of calls originating in either an IP network or a cellular network based on number prefixes. The inter-working functions comprise an application server programmed to communicate with a user device as a client. The server provides a staging point for cellular supplementary services while anchoring calls, retrieving configurations from cellular network elements and applying appropriate routing based on these configuration and the current state of a call.

Description

INTRODUCTION Field of the Invention The invention relates to a roaming gateway for mobile devices including wireless computers and other mobile/wireless devices.

Prior Art Discussion The 3GPP IP Multimedia Subsystem (IMS) is rapidly becoming the de facto standard for real-time multimedia communications services. Although the IMS was originally specified for 3G mobile networks, it also provides a service deployment architecture for any fixed or wireless network, and all IP-based networks such as WiFi, corporate enterprise LANS, and the public lntcmet. IMS standards define open interfaces for session management, access control, mobility management, service control, and billing. This allows the network provider to offer a managed SIP network, with all the carrier-grade attributes of the switched circuit network, but at a lower cost and with increased flexibility. In addition, the use of SIP as a common signalling protocol allows independent software developers to leverage a broad range of third party application servers, media servers, and SIP-enabled end user devices to create next generation services.

IMS is access independent, as it supports IP to IP sessions over fixed line IP, 802.11, 802.15, CDMA, packet data along with GSM/EDGE/UMTS and other packet data technologies. IMS is a standardised reference architecture that consists of connection control, session control, media transport, subscriber profile management, subscriber data management and an applications services framework enabling a multitude of new and innovative services.

IMS is independent of the underlying access technology and this is seen as the key driver behind the convergence of fixed, mobile and enterprise telephony. IMS is seen

Claims (1)

1. A roaming gateway comprising at least one IP network interface, and at least one cellular network interface, and an inter-working means for inter—working between a wireless IP network and a cellular network, wherein the inter- working means comprises means for communicating with user devices in an IP network according to a machine-level subscribe-and—notify event package protocol for managing handover of mobile devices roaming between IP and cellular networks, and comprises means for polling a cellular network for subscriber status on that cellular network in the absence of a mobility event package; wherein the inter-working means comprises HSS functionality programmed to access data on a HLR of a cellular network and to perform HSS operations using said data; wherein the inter—working means comprises means for applying routing policies specific to call types, allowing or disallowing the anchoring of calls originating in either an IP network or a cellular network based on number prefixes; and wherein the inter-working means comprises an application server programmed to communicate with a user device as a client. A roaming gateway as claimed i11 claim 1, wherein the server comprises means for providing a staging point for cellular supplementary services while anchoring calls, retrieving configurations from cellular network elements and applying appropriate routing based on these configurations and the current state of a call. A roaming gateway as claimed in claims 1 or 2, wherein the inter-working means comprises means for applying anchoring or handover criteria according to geographic location information relating to the current location of the subscriber, thereby avoiding tromboningt A roaming gateway as claimed in any preceding claim, wherein the inter- working means uses a mobility event package to coordinate transfer of user- created messages between user devices and the gateway in mobile originating cases, and for translating this message for onward delivery. A roaming gateway as claimed in claim 4, wherein the inter-working means comprises means for including event package formatting and bearer information. A roaming gateway as claimed in claims 4 or 5, wherein the inter-working means comprises means for obtaining formatting and bearer information from a network and from configuration settings. A roaming gateway as claimed in any preceding claim, wherein the inter- working means comprises means for acting as a proxy VLR and as a proxy SGSN for the purposes of intercepting relevant mobile terminated voice calls or messages from a cellular network, for a subsequent delivery attempt via [MS protocol. A roaming gateway as claimed in any preceding claim, wherein the inter- working means comprises means for communicating with an SMSC in a cellular network to indicate a preference to receive messages for particular subscribers for whom it may subsequently attempt delivery of messages. A roaming gateway as claimed in any preceding claim, wherein the inter- working means comprises means for translating user-originating requests for configuration of stored supplementary service data into a format recognizable by a cellular network acting as a primary data store for that subscriber, or by intelligent network equipment. A roaming gateway as claimed in any preceding claim, wherein the inter- working means comprises means for applying priority to registered devices and for routing services according to preferences and capabilities of those devices and the available networks. A roaming gateway as claimed in any preceding claim, wherein the server comprises means for receiving VolP call setup requests in a user device mobility event notify package and for originating a call to a called device. A roaming gateway as claimed in any preceding claim, wherein the server comprises means for receiving from a user device a notification of requested hand-over, the notification being part of a mobility event package, and means for transmitting to the user device a temporary reference number in response. A roaming gateway as claimed in any preceding claim, wherein the server comprises means for receiving in a mobility event package from a user device capability data for the device, and the inter—working means comprises means for using said date for delivery of messages to said device. A roaming gateway as claimed in any preceding claim, wherein the inter- working means comprises means for maintaining user device presence indications upon receipt of device notifications in mobility event packages. A computer readable medium comprising software code for performing operations of a gateway of any preceding claim when executing on a digital