Method for performing handover and roaming functions in radio networks

The present invention relates to a method for performing handover and roaming procedures between a mobile radio communication terminal of a user and access stations, which may belong to different, different management and / or access technology differently designed radio networks.

Nowadays operated and planned cellular networks allow a handover procedure, ie a handover, in accordance with the respective specifications within each network and a roaming procedure with partner networks, ie a cross-network handover, provided that the respective home network and a partner network in question maintain functioning communications links and administratively an agreement was reached. Short-range radio networks, such as Bluetooth networks or wireless LAN networks that implement handover and roaming procedures primarily proprietary or application-level with direct user interaction, which can be made through a Web browser, for example in an authentication at the access point. Details regarding the expiry of such procedures are included in the mobile phone specifications, eg ETSI, and the specifications for short-range wireless (Bluetooth, Wireless LAN, HomeRF).

From DE 101 45 753 Al, for example a method for supporting a handover and roaming procedure in a multi-cell radio system based on the Bluetooth standard is known. Here, the transmission field strength is first measured by lying within range of a mobile terminal access points based on a provided in accordance with the Bluetooth standard in the terminal link quality monitoring; then the access points to transmit measured field strength are evaluated and finally the one access point is selected for a handover or roaming procedure for the handset in favor of an optimal compound in its current position measures the largest transmission field strength. Since this is so this is a handover and roaming procedure within a pure Bluetooth wireless network, a use of different wireless networks with different management and / or different access technology is therefore not possible.

From US 6,167,250 a method for determination of tariff rates is known, which are calculated from at least two candidate-providers of wireless services to which a roaming mobile terminal can access. Here, a registration to a first candidate service provider by the mobile telephone is carried out. Subsequently, a request for subscriber information is sent along with the intended tariff rate, which is calculated from the first candidate service provider to the home service provider associated with the mobile terminal. There is a second candidate service provider is at least determined on the mobile terminal can access. Finally, tariff rates are determined by the second candidate service provider by the home service provider.

From DE 102 61 201 A1 a process for making a connection between a mobile station and a Kommunikatikonsnetzwerk is known, in which a connection between the mobile station and the network after selection of the connection parameters is performed via an access point. For this purpose, an automatic detection of usable connectivity to different networks in different standards and frequency bands, by by selecting a first standard verification of connectivity is done within this standard. Subsequently, a second standard is selected by also a check of the connection possibility. At the there is a storage of the standard, with the option to connect was found characterizing parameters. The establishment of a connection to an access point at which communicates via a standard is programmatically by filter or run manually.

In the previously known method for performing handover or roaming procedures with possibility to access different wireless networks (inter-network handover, Inter-network roaming) a direct interaction with the user is required, for example, by entering user data or changes in in the operating system of the mobile radio communication terminal of the user stored settings.

The present invention is now based on the object to provide for performing handover and roaming procedures, a process which allows a low-cost, uninterrupted use of radio networks with different physical access technology or wireless networks with the same physical access technology, but independent administration.

According to the present invention which relates to a method for performing handover and roaming procedures of the aforementioned type, this object is achieved in an advantageous manner in that the mobile radio communication terminal of the user via any available network connection to a central , cross-network database accesses, in the reachable on instantaneous location of the user's wireless networks and their access parameters are included as information that the filling of the database is done with this information either by their owners or by observation and feedback of those mobile radio communication terminals or access stations, who use the method, and that based on these obtained from the database information, the respective suitable access radio network is selected without further necessary interactions of the user.

Advantageous and expedient further developments of the method according to the present invention are i n the indicated directly or indirectly relating to back the claim 1 claims.

Advantageously, in the central, cross-network database except registered there, radio networks and received their access parameters as information also the wetting properties of the different registered radio networks and their location, time and load-dependent network availability features.

"Neighbor list" for mobile radio communication terminals are expediently provided by a central entity on request of the mobile user for a specific location for the targeted selection of a wireless network.

It is also advantageous that is selected on the basis of information received from the database by means of a program in the mobile radio communication device of the user in each case the appropriate access radio network.

The database can be between network operators and Internet access are different, so that for example cheap local internet connection can be compared to network-wide access of one or more operators preferred or advantageous access one and the same provider is selected when this example, different tariffs or different, such as circuit-switched or packet-switched media offering.

Advantageously, it may be provided an interface for the integration of optimization method for selecting a wireless network. Such optimization methods can deliver the highest availability and / or the lowest transmission costs of wireless networks involved concern.

The method of the present invention can be advantageously used in cellular networks, such as. In GSM networks or UMTS networks, and in short-range wireless networks, such as used in Bluetooth networks, wireless LANs, or HomeRF networks Of particular interest is the method according to the present invention in connection with public wireless Internet access points (hotspots), with cross-network location-based services and in an ad hoc networking.

The invention is illustrated below with the aid of an additionally illustrated by drawings example with three in their coverage area partially overlapping radio networks of different technologies. Show it:<dl id="dl0001"><dt>Fig.1</dt><dd>a schematic representation of the filling of the various radio networks allocated database, and</dd><dt>Fig.2</dt><dd>likewise in a schematic representation, the request of a mobile user with a radio communication terminal for available wireless networks in its environment with appropriate database response.</dd></dl>

In the schematically illustrated in Fig.1 and Fig.2 example, a service area UMTS is shown a UMTS mobile network. Within the service area of ​​UMTS this UMTS mobile network are still a Bluetooth wireless network BT and wireless LAN Wireless Network. The UMTS mobile network, the Bluetooth radio network and the wireless radio network have different physical access technologies.

According to the in Fig.1 example shown there are three mobile users N1, N2 and N3 with their radio communication devices in the coverage area of ​​the UMTS UMTS mobile network. The radio communication terminals of three mobile users N1, N2 and N3 fall back on one of the various available network connections UMTS, BT, WLAN and WiMax and the Internet INT to a central, cross-network database DB. This database DB will contain all available at the instantaneous location of the users N1, N2 and N3 radio networks and their access parameters as information.

As information is entered there, the respective network characteristics and location, time and load-dependent network availability information. In the example shown in Figure 1, the filling of the database DB is done with this information through observation and feedback of three mobile users N1, N2 and N3, which are located in the coverage areas of the three networks UMTS, BT and WLAN.

The first mobile user N1 observed in its position that in addition to access to the UMTS radio network UMTS there optional access to a Bluetooth wireless network BT is present and shares as feedback information ① the database DB this observation, including longitude / latitude, the Access Point name and the access point address with.

The second mobile user N2 observed in its position that there is access to a UMTS mobile network UMTS and notifies the feedback information ② the database DB this observation including geographic Gaußkrüger coordinates and the name and the network code of the available UMTS radio network UMTS with.

The third mobile users N3 observed in its position that there optional access to a wireless Wireless Network is available in addition to the access to the UMTS radio network UMTS and shares as feedback information ③ the database DB this observation, including longitude / latitude , the wireless SSID concerned and the account data of the available there wireless radio network WLAN. The mobile users N1, N2 and N3 have the available wireless networks access to the Internet INT and the database DB.

It will be noted that the filling of the database DB with information can in principle be made by operators of the networks UMTS, BT, WLAN and WiMax and need not be made through observations and feedback of mobile users N1, N2 and N3.

Based on these obtained from the database DB information that each suitable access radio network can be selected without further necessary interactions of the user N by a program on the radio communication terminal of a mobile user N. 2 shows in this connection schematically directed to the database DB requests of on a shown in broken line path P advancing in the direction indicated by an arrow the direction of movement user N for available wireless networks in its vicinity at different times (t = 0) (t = 10) and (t = 20). In the example, the database DB is the mobile user N is the information ①, that in the illustrated movement of the user N at the time (t = 0) is a UMTS radio network UMTS is accessible having to use the following parameters: Network Code 261-01, GRPS -Costs xx € / MB; ISP A, number 089 ...., Username / Password. The information ① also indicates that at the time (t = 10), the same UMTS radio network UMTS are accessible using the following parameters with the network code 261-01 and GRPS cost of xx € / MB and also a Bluetooth wireless network BT: Addr : 00: 3c: 23: 0c: 00: 07, costs € 0 / MB, load 5 (7) user. Furthermore, are the information ① to that at the time (t = 20) also the same UMTS radio network UMTS with the network code 261-01 and GRPS cost of xx € / MB, but beyond even a wireless Wireless Network is available with the following parameters: SSID "public", costs xx € / h.

LIST OF REFERENCE NUMBERS

<dl id="dl0002" compact="compact"><dt>BT</dt><dd>Bluetooth wireless networking</dd><dt>DB</dt><dd>Database</dd><dt>INT</dt><dd>Internet</dd><dt>N; N1, N2, N3</dt><dd>user</dd><dt>P</dt><dd>path</dd><dt>UMTS</dt><dd>Coverage area UMTS radio network</dd><dt>WIRELESS INTERNET ACCESS</dt><dd>Wireless LAN radio network</dd></dl>