Handover between mobile communication networks

• US 6,385,451 B1
• Filed: 09/13/1999
• Issued: 05/07/2002
• Est. Priority Date: 09/14/1998
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Inventors: Turunen, Matti, Kalliokulju, Juha
• Primary Examiner(s): Hunter, Daniel
• Assistant Examiner(s): Woldetatios, Yemane
• Application Number:
  US09/394,951
• Time in Patent Office: 967 Days
• Field of Search: 455/436, 455/437, 455/438, 455/439, 455/426, 455/422, 455/435, 370/331, 370/332
• US Class Current: 455/437
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 36/28 involving a plurality of connections, e.g. multi-call or multi-bearer connections

Abstract

The invention relates to a method for handing over a connection between a first (NW1) and a second mobile communication network (NW2) in a wireless terminal (MS1). In the method, at least one data transmission connection is established for the purpose of transmitting information between the wireless terminal (MS1) and one said mobile communication network (NW1, NW2). In the first mobile communication network, the connection type is either connection-oriented (HSCSD) or connectionless (GPRS), and in the second mobile communication network (NW1, NW2), at least two traffic classes with different transmission features are defined and one of them is selected for the data transmission connection of the second mobile communication network (NW1, NW2). In the method, it is also examined what active data transmission connections the wireless terminal (MS1) has to the mobile communication network (NW1, NW2) handing over the connection. When handing over a connection from the first mobile communication network (NW1) to the second mobile communication network (NW2), the connection type of each active data transmission connection is examined, the traffic class corresponding to each active data transmission connection type is defined in the second mobile communication network (NW2), and a connection according to the defined traffic class is established for each data transmission connection in the second mobile communication network (NW2). When handing over a connection from the second mobile communication network (NW2) to the first communication network (NW1) the traffic class of each active data transmission connection is examined, the connection type corresponding to each active data transmission traffic class is defined in the first mobile communication network (NW1), and a connection according to the defined connection type is defined for each data transmission connection in the first mobile communication network (NW1).

Claims

1. A method for handing over a connection between a first (NW1) and a second mobile communication network (NW2) in a wireless terminal (MS1), in which method at least one data transmission connection is established for the purpose of transmitting information between the wireless terminal (MS1) and one said mobile communication network (NW1, NW2), the connection type in the first mobile communication network being either connection-oriented (HSCSD) or connectionless (GPRS), and wherein at least two traffic classes with different transmission features are defined in the second mobile communication network (NW1, NW2) and one of them is selected for the data transmission connection of the second mobile communication network (NW1, NW2), characterized in that in the method:

it is examined what active data transmission connections the wireless terminal (MS1) has to the mobile communication network (NW1, NW2) handing over the connection,

when handing over a connection from the first mobile communication network (NW1) to the second mobile communication network (NW2), the connection type of each active data transmission connection is examined, the traffic class corresponding to each active data transmission connection type is defined in the second mobile communication network (NW2), and a connection according to the defined traffic class is established for each data transmission connection in the second mobile communication network (NW2),

when handing over a connection from the second mobile communication network (NW2) to the first communication network (NW1), the traffic class of each active data transmission connection is examined, the connection type corresponding to each active data transmission traffic class is defined in the first mobile communication network (NW1), and a connection according to the defined connection type is defined for each data transmission connection in the first mobile communication network (NW1).

2. The method according to claim 1, characterized in that

at least a guaranteed service quality level and a best effort quality level are defined for the first mobile communication network (NW1), wherein a connection-oriented connection is used for the data transmission connections selected for the guaranteed service quality, and a connectionless connection is used for the data transmission connections selected for the best effort quality,

that at least a first and a third traffic class are defined for the second mobile communication network (NW2),

that when handing over a connection from the first (NW1) to the second mobile communication network (NW2), the first traffic class is selected for the active guaranteed service data transmission connections in the second data transmission network (NW2), and the third traffic class is selected for the active best effort data transmission connections in the second data transmission network (NW2), and

that when handing over a connection from the second (NW2) to the first mobile communication network (NW1), the guaranteed service quality is selected for the active data transmission connections of the first traffic class in the first data transmission network (NW1), and the best effort quality is selected for the active data transmission connections of the third traffic class in the first data transmission network (NW1).

3. The method according to claim 1, characterized in that a traffic class or a connection type is selected for the data transmission connection to be activated at least partly on the basis of the features of the information to be transmitted, such as transmission rate, delay and error probability.

4. The method according to claim 1, characterized in that

for the first mobile communication network (NW1), also a controlled load service quality is also defined, for which a packet-format connection is used in selected data transmission connections, and that

for the second mobile communication network (NW2), also a second and a fourth traffic class are defined.

5. The method according to claim 1, characterized in that for data transmission connections requiring real-time data transmission, a connection-oriented connection (HSCSD) is selected as the connection type in the first mobile communication network (NW1), and the first or the second traffic class in the second mobile communication network (NW2 ).

6. The method according to claim 1, characterized in that the connection-oriented connection of the first mobile communication network (NW1) is either a transparent connection for which transmission resources are allocated in the first mobile communication network (NW1) in such a way that the connection has a substantially fixed data transmission rate and a fixed propagation delay, or a non-transparent connection whose allocated transmission resources can be changed during the connection in such a way that the data transmission rate and/or the propagation delay can be substantially altered.

7. The method according to claim 1, characterized in that the first mobile communication network (NW1 ) is a GSM cellular network, and the second mobile communication network (NW2) is a UMTS cellular network.

8. The method according to claim 7, characterized in that the connection-oriented connection is a high-speed circuit-switched connection (HSCSD), and the connectionless connection is a packet-switched connection (GPRS).

9. A communication system, which comprises at least a first (NW1) and a second mobile communication network (NW2), a wireless terminal, means (GGSN, GWMSC) for activating at least one data transmission connection in order to transmit information between the wireless terminal (MS1) and one said mobile communication network (NW1, NW2), and means (GGSN, GWMSC) for handing over a connection between the first (NW1) and the second (NW2) mobile communication network in the wireless terminal (MS1), the first mobile communication network (NW1) comprising means (GGSN, MSC) for establishing a connection as a connection-oriented connection and/or as a connectionless connection, and at least two traffic classes being defined in the second mobile communication network (NW2) for the data transmission connections, characterized in that the communication system also comprises:

means for examining the active connections between the wireless terminal (MS1) and the mobile communication network (NW1, NW2) handing over the connection,

means for handing over the connection comprising;

means for examining the connection type of the active data transmission connections in the first mobile communication network (NW1), means for defining a traffic class corresponding to each active connection type of the data transmission in the second mobile communication network (NW2), and means for establishing a connection according to the traffic class defined for each data transmission connection in the second mobile communication network (NW2), and

means for examining the traffic class of the active data transmission connections in the second mobile communication network (NW2), means for defining a connection type corresponding to each active traffic class of the data transmission connection in the first mobile communication network (NW1), and means for establishing a connection according to the defined connection type for each data transmission connection in the first mobile communication network (NW1).

10. A wireless terminal (MS1) comprising means for attaching to a communication system, which contains means (RAN, BSS) for establishing a data transmission connection at least to a first (NW1) and to a second mobile communication network (NW2), which first mobile communication network (NW1) comprises means (GGSN, MSC) for establishing a connection as a connection-oriented connection and/or as a connectionless connection, and in the second mobile communication network (NW2), at least two traffic classes are defined for data transmission connections, characterized in that the wireless terminal (MS1) also comprises:

means for examining the active connections between the wireless terminal (MS1) and the mobile communication network (NW1, NW2) handing over the connection,

means for handing over the connection comprising;

means for examining the connection type of the active data transmission connections in the first mobile communication network (NW1), means for defining a traffic class corresponding to each active connection type of the data transmission in the second mobile communication network (NW2), and means for establishing a connection according to the traffic class defined for each data transmission connection in the second mobile communication network (NW2), and

means for examining the traffic class of the active data transmission connections in the second mobile communication network (NW2), means for defining a connection type corresponding to each active traffic class of the data transmission connection in the first mobile communication network (NW1), and means for establishing a connection according to the defined connection type for each data transmission connection in the first mobile communication network (NW1).