Browse Prior Art Database

Switching Voice-over-IP connections between cellular networks

IP.com Disclosure Number: IPCOM000124515D
Original Publication Date: 2005-May-20
Included in the Prior Art Database: 2005-May-20
Document File: 1 page(s) / 365K

Publishing Venue

Siemens

Related People

Juergen Carstens: CONTACT

Abstract

Switching a RTP (Real-time Transport Protocol) data stream, e.g. a Voice-over-IP (VoIP) data stream, from one cellular network to another emerges technical challenges: A short interruption of the data flow is noticeable by the user and attracts his attention. With today's solutions, this short time of interruption in the data flow is inevitable. The following solution is proposed to solve this problem: 1) The terminal initiates a connection to another terminal, e.g. a real-time VoIP service. Any protocol/application can be used by the terminal to initiate this connection. Normally some standardized protocols are used for the signaling between the two terminals (e.g. initialization of the connection), and a RTP connection can be used for the exchange of user data directly between the two terminals. The RTP connection is based on the IP addresses of the mobile terminal and on the port number of the application. Fig. 1 shows the calling terminal (IP Nr. 1) and the called terminal (IP Nr. 2). 2) One of the two terminals (e.g. the calling one) detects a new access network and attaches to it. The new IP address is made available to the terminal architecture. Fig. 1 shows the calling terminal with IP Nr. 1 and the called terminal with IP Nr. 3. 3) A small application running on the calling terminal informs the called terminal about the new IP address (IP Nr. 3). This small application can transfer a file, send a SMS or use any other suitable service.

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Switching Voice-over-IP connections between cellular networks

Idea: Alessandra Pandolfi, DE-Munich

Switching a RTP (Real-time Transport Protocol) data stream, e.g. a Voice-over-IP (VoIP) data stream, from one cellular network to another emerges technical challenges: A short interruption of the data flow is noticeable by the user and attracts his attention. With today's solutions, this short time of interruption in the data flow is inevitable.

The following solution is proposed to solve this problem:

1) The terminal initiates a connection to another terminal, e.g. a real-time VoIP service. Any protocol/application can be used by the terminal to initiate this connection. Normally some standardized protocols are used for the signaling between the two terminals (e.g. initialization of the connection), and a RTP connection can be used for the exchange of user data directly between the two terminals. The RTP connection is based on the IP addresses of the mobile terminal and on the port number of the application. Fig. 1 shows the calling terminal (IP Nr. 1) and the called terminal (IP Nr. 2).

2) One of the two terminals (e.g. the calling one) detects a new access network and attaches to it. The new IP address is made available to the terminal architecture. Fig. 1 shows the calling terminal with IP Nr. 1 and the called terminal with IP Nr. 3.

3) A small application running on the calling terminal informs the called terminal about the new IP address (IP Nr. 3). This sma...