Packet transfer scheme and mobile communication system

• US 5,963,550 A
• Filed: 08/29/1996
• Issued: 10/05/1999
• Est. Priority Date: 01/06/1995
• Status: Expired due to Term

• Current Assignee: NTT Mobile Communications Network Inc. (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Mobile Communications Network Inc. (Nippon Telegraph and Telephone Corporation)
• Inventors: Sugiyama, Kazuo, Shimokawa, Atsushi, Ikeda, Kimio, Yamamoto, Koji, Hirata, Shoichi, Nakajima, Akihisa, Sotoyama, Masumi
• Primary Examiner(s): Nguyen, Chau
• Assistant Examiner(s): VANDERPUYE, KENNETH N
• Application Number:
  US08/700,404
• Time in Patent Office: 1,132 Days
• Field of Search: 455/456, 455/466, 455/440, 455/457, 455/422, 455/428, 455/432, 455/435, 455/433, 455/436, 455/437, 455/438, 455/439, 455/560, 370/338, 370/329, 370/352, 370/389, 370/331, 370/386, 370/349, 375/356
• US Class Current: 370/349
• CPC Class Codes: H04W 8/08 Mobility data transfer
• CPC Class Codes: H04W 8/14 between corresponding nodes
• CPC Class Codes: H04W 92/22 between access point controllers
• CPC Class Codes: H04W 92/24 between backbone network devices

Abstract

In order to provide a packet transfer scheme in which various data can easily be used commonly with other communication methods and a packet can be transferred at a high speed, a mobile communication system comprises a database (20) for storing an identification number of a mobile terminal (40) and location information indicating a zone in which the mobile terminal is currently located, a packet switch (10), and another packet switch (30) capable of communication when the mobile terminal (40) is located in a zone under the packet switch (30). The packet switch (10) inquires of the database (20) about the location information of the mobile terminal (40) when the packet switch (10) receives a packet addressed to the mobile terminal (40). When the mobile terminal (40) is located in the zone under the packet switch (30), the packet is transferred to the mobile terminal (40) through the packet switch (30). Owing to this arrangement, the number of packet switches necessary for transferring the packet to the mobile terminal is two at the most. Thus, the packet can be transferred rapidly.

Claims

1. A packet transfer scheme used in a mobile communication system comprising a database for storing an identification number of a mobile terminal and location information showing a zone in which said mobile terminal is currently located, and for rewriting said location information in accordance with a request from said mobile terminal, a plurality of first packet switches, each having a temporary storage means with a higher access speed than said database, a second packet switch capable of communicating with said mobile terminal in case said mobile terminal is located in a given zone, said packet transfer scheme being characterized in that:

each of said first packet switches inquires of said database about the location information when it receives a packet addressed to said mobile terminal;

said database provides each of said first packet switches with the location information in response to said inquiry;

each of said first packet switches writes the location information provided from said database into its respective temporary storage means, and when said location information indicates said given zone, transfers said packet to said second packet switch, and when said packet addressed to said mobile terminal is received again after the initial reception of said packet, reads said location information from its temporary storage means and transfers said re-received packet to said second packet switch;

said second packet switch transfers said packet to said mobile terminal when said second packet switch receives said packet from one of said first packet switches;

said database requests each of said first packet switches to rewrite said location information when said location information is rewritten in said database; and

each of said first packet switches renews its respective location information when said location information is stored in its corresponding temporary storage means.

6. The packet transfer scheme according to one of claims 1 through 4, characterized in that:

when said second packet switch receives said packet again from said one of said first packet switches before said one of said first packet switches receives said location information rewrite request from said database or said second packet switch,

said second packet switch sends a transfer impossible notice to said one of said first packet switches informing that a transfer of said packet is impossible to perform;

said one of said first packet switches inquires of said database about said new location information of said mobile terminal upon receipt of said transfer impossible notice;

said database provides said one of said first packet switches with said new location information in response to said inquiry; and

said one of said first packet switches writes said new location information in said temporary storage means upon receipt of said new location information from said database.

2. A packet transfer scheme used in a mobile communication system comprising a database for storing an identification number of a mobile terminal and location information showing a zone in which said mobile terminal is currently located, and for rewriting said location information in accordance with a request from said mobile terminal, a plurality of first packet switches, each having a temporary storage means with a higher access speed than said database, a second packet switch capable of communicating with said mobile terminal in case said mobile terminal is located in a given zone, said packet transfer scheme being characterized in that:

each of said first packet switches inquires of said database about the location information when it receives a packet addressed to said mobile terminal;

said database provides each of said first packet switches with the location information in response to said inquiry;

each of said first packet switches writes the location information provided from said database into its respective temporary storage means, and when said location information indicates said given zone, transfers said packet to said second packet switch, and when said packet addressed to said mobile terminal is received again after the initial reception of said packet, reads said location information from its temporary storage means and transfers said re-received packet to said second packet switch;

said second packet switch transfers said packet to said mobile terminal when said second packet switch receives said packet from one of said first packet switches;

said second packet switch requests each of said first packet switches to rewrite said location information when said location information is rewritten in said database; and

each of said first packet switches renews its respective location information when said location information is stored in its corresponding temporary storage means.

3. A packet transfer scheme used in a mobile communication system comprising a database for storing an identification number of a mobile terminal and location information showing a zone in which said mobile terminal is currently located, and for rewriting said location information in accordance with a request from said mobile terminal, a plurality of first packet switches, each having a corresponding temporary storage means with a higher access speed than said database a second packet switch capable of communicating with said mobile terminal in case said mobile terminal is located in a given zone, said packet transfer scheme being characterized in that:

each of said first packet switches inquires of said database about the location information when it receives a packet addressed to said mobile terminal;

said database provides each of said first packet switches with the location information in response to said inquiry;

each of said first packet switches writes the location information provided from said database into its corresponding temporary storage means, and when said location information indicates said given zone, transfers said packet to said second packet switch, and when said packet addressed to said mobile terminal is received again after the initial reception of said packet, reads said location information from its corresponding temporary storage means and transfers said re-received packet to said second packet switch;

said second packet switch transfers said packet to said mobile terminal when said second packet switch receives said packet from one of said first packet switches;

said database requests each of said first packet switches which previously stored said location information in its corresponding temporary storage means, to rewrite said location information when said location information is rewritten in said database; and

each of said first packet switches, which received the rewrite request, renews its respective location information stored in its corresponding temporary storage means.

4. A packet transfer scheme used in a mobile communication system comprising a database for storing an identification number of a mobile terminal and location information showing a zone in which said mobile terminal is currently located, and for rewriting said location information in accordance with a request from said mobile terminal, a plurality of first packet switches, each having a corresponding temporary storage means with a higher access speed than said database, a second packet switch capable of communicating with said mobile terminal in case said mobile terminal is located in a given zone, said packet transfer scheme being characterized in that:

each of said first packet switches inquires of said database about the location information when it receives a packet addressed to said mobile terminal;

said database provides each of said first packet switches with the location information in response to said inquiry;

each of said first packet switches writes the location information provided from said database into its corresponding temporary storage means, and when said location information indicates said given zone, transfers said packet to said second packet switch, and when said packet addressed to said mobile terminal is received again after the initial reception of said packet, reads said location information from its corresponding temporary storage means and transfers said re-received packet to said second packet switch;

said second Packet switch transfers said packet to said mobile terminal when said second packet switch receives said packet from one of said first packet switches;

said second packet switch requests each of said first packet switches which previously stored said location information in its corresponding temporary storage means, to rewrite said location information when said location information is rewritten in said database; and

each of said first packet switches, which received the rewrite request, renews its respective location information stored in its corresponding temporary storage means.

5. A packet transfer scheme used in a mobile communication system comprising a database for storing an identification number of a mobile terminal and location information showing a zone in which said mobile terminal is currently located, and for rewriting said location information in accordance with a request from said mobile terminal, a plurality of first packet switches, each having a corresponding temporary storage means with a higher access speed than said database, a second packet switch capable of communicating with said mobile terminal in case said mobile terminal is located in a given zone, said packet transfer scheme being characterized in that:

each of said first packet switches inquires of said database about the location information when it receives a packet addressed to said mobile terminal;

said database provides each of said first packet switches with the location information in response to said inquiry;

each of said first packet switches writes the location information provided from said database into its corresponding temporary storage means, and when said location information indicates said given zone, transfers said packet to said second packet switch, and when said packet addressed to said mobile terminal is received again after the initial reception of said packet, reads said location information from its corresponding temporary storage means and transfers said re-received packet to said second packet switch;

said second packet switch transfers said packet to said mobile terminal when said second packet switch receives said packet from one of said first packet switches;

said second packet switch sends a transfer impossible notice to said one of said first packet switches informing that a transfer of said packet is impossible to perform when said packet is transferred again from said one of said first packet switches after said mobile terminal moves outside said given zone;

said one of said first packet switches, upon receipt of said transfer impossible notice, inquires of said database about a new location information of said mobile terminal;

said database provides said one of said first packet switches with said new location information in response to said inquiry; and

said one of said first packet switches writes said new location information in its corresponding temporary storage means upon receipt of said new location information from said database.