Patent Application
20070064649
This invention pertains to management by a mobile terminal of internet protocol (IP) communication in a multi-bearer environment.
In a multi-bearer environment, a mobile terminal can access IP services via several access IP networks that may have overlapping IP address ranges. On the other hand, coping with a set of several access networks is difficult unless there is enough information to enable the mobile terminal to manage the data connections.
The user or client application is typically most interested in the services that are available from the destination IP network. A common example of the destination IP network is the Internet, which can be accessed via several access networks. Ideally, the data connections to the Internet or other destination network should be moveable from one access network to another with little or no interference to the user of mobile terminal.
The basic problem is to describe the network topology to the mobile terminal in such a way that the mobile terminal can automatically select the best possible access to each individual data connection. That problem comprises the following four items: (1) making the connection selection as simple as possible for the user of the mobile terminal; (2) selecting the best available access network automatically; (3) providing information as to which access networks are interchangeable in terms of IP routing and in terms of application level services; and (4) structuring configuration information in such a way that it can be easily managed with an Over the Air (OTA) configuration and manual configuration done by the user. Items 1-3 are not fulfilled by currently available technology. Item 4 is worth mentioning, because configuration settings will inevitably become more complicated, and it is essential to get the configuration right so that automatic connection selection and seamless roaming can occur.
The SYMBIAN operating system (OS) has had an identifier called “Network ID” since version 7.0S of the SYMBIAN OS. The purpose of that identifier is to make several simultaneous IP data connections possible, for example with overlapping IP addresses. This SYMBIAN Network ID assists with IP routing problems in a multi-homing environment, but so far it has not been adapted for phone products.
When someone connects his or her network to two different Internet service providers (ISPs), that exemplifies multi-homing, which provides redundancy and network optimization by selecting the ISP offering the best path to a resource. In other words, multi-homing involves the ability to use multiple concurrent IP addresses. Where a user may be streaming audio and browsing, while performing a back-office synchronization and receiving an MMS message, he or she is likely to be using multiple IP addresses. Multi-homing is not limited to the telephony side; it also allows different IP addresses for other services such as Bluetooth wireless technology, PC connectivity, or ethernet. The term multi-homing is used in this application broadly, to include any multi-bearer situation.
In addition to not being adapted to phones, the SYMBIAN Network ID offers only a partial solution to the whole problem of connection management and seamless mobility. The “IPv6 Scoped Address Architecture” (http://www1.ietf.org/proceedings_new/04nov/IDs/draft-ietf-ipv6-scoping-arch-02.txt downloaded on Sep. 1, 2005) can also be seen as background for the present invention, in the limited sense that it is used to distinguish between interfaces that are connected to overlapping IP address spaces. Unfortunately, however, there has so far not been a complete solution for connection management in a multi-homing environment.
Network topology is described in a phone in such a way that automated selections can be made in the data connection setup phase and during the connection. This solves the problem of how to automate connection selection and roaming. Roaming of data flows is enabled between interfaces connected to IP spaces that possibly overlap, and this is achieved by presenting connection parameters in a triplet configuration. Each triplet includes parameters for an access point, and access network, and a destination.
The present invention extends the idea of a network ID further, and consequently provides a more complete solution for the problem of connection management and seamless mobility. The present invention provides a mechanism to enable the roaming of data flows between interfaces connected to possibly overlapping IP spaces, which has not been done before.
To this end, a triplet configuration is used to represent connection parameters. The first part of the triplet is an access point (also known as an “internet access point” or IAP) providing parameters that are specific to an access mechanism and subscriber, such as dial-up number (CSD), Access Point Name APN (GPRS/WCDMA), username, password, and the like. The second part of the triplet is an Access Network ID which identifies the access IP network independent of the radio bearer. The Access Network ID can contain one or several interchangeable access points. Local services such as the Simple Mail Transfer Protocol (SMTP) server, the HTTP proxy, or the Mobile IP home agent must be reachable from any node within the access network. The third part of the triplet is a Destination Network ID that identifies the destination IP network whose service the mobile terminal/user is using. The Destination Network ID can contain one or several interchangeable access networks. The name resolution in the destination network must return the same answer from all the access networks within that destination network.
It is possible to move data flow from one connection to another and access the services of the original connection, within the destination network, but this usually requires an application to adapt or initiate such a connection change. This is called semi-seamless roaming, or application assisted roaming. Within an access network, it is possible to move data flows seamlessly from one connection to another with the help of mobile IP. Note that in some cases it is possible to use seamless roaming between access networks, although that use is not covered by the present invention.
The connection parameter triplet described above is used in both a data connection setup and when making roaming decisions for active connections. In the connection setup, this invention makes it possible for an application or user to activate a data connection to a certain destination network, such as the Internet or office intranet, and let middleware (i.e. software that connects two otherwise separate applications) take care of selecting the optimal available radio bearer automatically. Based on access and destination network information, the middleware can make decisions as to whether there is a better connection available for some of the existing data flows, and whether seamless roaming or application-assisted roaming should be used when moving the data flow from one connection to another. Thus, by describing the network topology in the phone in such a way that automated selections can be made in the data connection setup phase and during the connection, the problem is solved as to how connection selection and roaming can be automated.
The triplet configuration of the present invention can be seen as a hierarchical system where one destination network is reachable via several access networks, which in turn can be accessed via several access points (IAPs). An example configuration can be seen in the following table which maps to the network topology of
The set of configuration information shown in
The network table must contain an entry for each access network. Quite often, the access network is the same as the destination network (e.g. intranet). In those cases, only one entry is enough. If there are destination networks that are not access networks (e.g. the Internet), then they must also have an entry in the network table. The IAPs are associated with access network IDs.
The network table itself does not contain any mapping information between destination and access network entries; that would change the structure of the table and break binary compatibility (BC). Therefore, the complete list of destination networks can be found from the separate mapping table of the present invention, and that is the one that should be used (see left column in
The new components that take into account access and destination networks, and handle the automated connection selection and roaming decisions, are here called Bearer Manager and Mobility Policy Manager. Their position in the system architecture is described in
Turning now to
It is to be understood that all of the present figures, and the accompanying narrative discussions of best mode embodiments, do not purport to be completely rigorous treatments of the method, system, mobile device, and software product under consideration. A person skilled in the art will understand that the steps and signals of the present application represent general cause-and-effect relationships that do not exclude intermediate interactions of various types, and will further understand that the various steps and structures described in this application can be implemented by a variety of different sequences and configurations, using various different combinations of hardware and software which need not be further detailed herein.
