Automatic Switching and Failover Method and System for Messages and Voice Calls Between Cellular and IP Networks

1. A communication method for automatically switching between cellular networks and IP networks, the method comprising: using a full or partial mobile phone number or a result calculated from the full or partial mobile phone number as an identifier of a client or an user account or a part of the identifier of the client or the user account; and a sending user inputting or selecting the user account or the full or partial mobile phone number of a receiving user on a sending client to send a message to the receiving user, wherein if the sending client can reach a server on the IP networks and if there is the user account corresponding to the full or partial mobile phone number of the receiving user registered on the server and the user account is on line, the sending client sends a message to the server via the IP networks, and the server transfers the message to a receiving client via the IP networks; or the sending client sends the message directly via the IF networks to the receiving client; and wherein if there is no user account corresponding to the full or partial mobile phone number of the receiving user registered on the server or the user account is registered but offline, the sending client directly sends a short message to the full or partial mobile phone number of the receiving user via the cellular networks; wherein sent short messages or received short messages are uploaded to a database of the server via the IP networks, and wherein when a mobile client of the sending user or the receiving user can not access to the IP networks, the client stores an uploading short message, and maintains an order for the uploading short message, and uploads the uploading short message to the server when a mobile terminal accesses to the IP networks.

2. The communication method as claimed in claim 1 , wherein after the receiving client receiving an instant message, the receiving client displays the full or partial mobile phone number of the sending user and content of the message in the same fashion as how the receiving client displays SMS message received via the cellular networks.

3. The communication method as claimed in claim 1 , before the step of the sending client sending the short message to the receiving client via the cellular networks, further comprising following steps: the sending client determining whether the message is sent as short message via the cellular networks; and the sending client reminding the sending user whether the message may generate communication fees accordingly.

4. The communication method as claimed in claim 1 , wherein the server records an instant message transferred through the server, and stores the instant message transferred through the server and the short message uploaded from the clients as message history records.

5. The communication method as claimed in claim 4 , wherein a website is connected to the server via the IP networks, and the sending user sends the instant message to the receiving user who has registered on the server and is on line via a web client, and wherein the user can view the message history records in the database of the server via a browser of the website or the client.

6. The communication method as claimed in claim 1 , wherein the client updates online information of the contacts instantaneously.

7. An automatic switching communication system between cellular networks and IP networks, the communication system comprising clients and a server, the clients comprising a sending client and a receiving client; wherein a client is configured for sending an instant message to the server when a receiving user has registered on the server and is on line; or is configured for sending a short message to a full or partial mobile phone number of the receiving user when the receiving user has not registered on the server or the receiving user has registered on the server, but the receiving user is offline; wherein the server is configured for transmitting the instant message to the receiving client; and wherein the full or partial mobile phone number or a result calculated from the full or partial mobile phone number is provided as an identifier of the client or a part of the identifier of the client; wherein sent short messages or received short messages are uploaded to a database of the server via the IP networks, and wherein when a mobile client of a sending user or the receiving user can not access to the IP networks, the client stores an uploading short message, and maintains an order for the uploading short message, and uploads the uploading short message to the server when a mobile terminal accesses to the IP networks.