Mobile host, paging agent, packet communication system, and movement detection method

• US 20050249131A1
• Filed: 04/18/2005
• Published: 11/10/2005
• Est. Priority Date: 04/20/2004
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Okajima, Ichiro, Takahashi, Hideaki, Inoue, Masahiro, Umeda, Narumi
• Granted Patent: US 7,567,534 B2
• Time in Patent Office: Days
• US Class Current: 370/254
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 68/00 User notification, e.g. alerting and paging, for incoming communication, change of service or the like
• CPC Class Codes: H04W 76/20 Manipulation of established connections
• CPC Class Codes: H04W 80/02 Data link layer protocols
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 88/005 Data network PoA devices

Abstract

A mobile host 2 as an embodiment of the invention comprises a data link layer connection establishment notification unit 202 for notifying the network layer that a connection to a link layer in the data link has been established during a Dormant state; a router information requesting unit 203 for transmitting, in response to the notification by the data link layer connection establishment notification unit 202, a router request signal which requests for transmission of router advertisement information to the access router 3 existing on the access link 4 to which the mobile host is connected; and a network layer movement detection unit 204 for detecting a default router, based on the router advertisement information returned from the access router 3 in response to the router request signal.

Claims

1. A mobile host comprising:

a communication status detection means for detecting that the communication status in the network layer is in a Dormant state;

a data link layer connection establishment notification means for notifying the network layer that a connection to a link in the data link layer has been established, if a Dormant state is detected by said communication status detection means;

a network layer movement detection means for detecting a default router, triggered by notification from said data link layer connection establishment notification means.

2. The mobile host according to claim 1, further comprising a router information requesting means for transmitting a Router Solicitation which requests for transmission of router advertisement information to the access router existing on the access link to which said mobile host is connected, in response to the notification by said data link layer connection establishment notification means, wherein

said network layer movement detection means detects a default router, based on the router advertisement information returned from said access router, in response to said Router Solicitation.

3. A mobile host comprising:

an access node notification means for notifying the information with regard to the address of access nodes existing on the access link to which said mobile host is connected, to a paging agent which manages the movement status of said mobile host;

an access node list requesting means for requesting said paging agent for transmission of an access node list which is the address list of the access nodes existing on the neighboring link of said access link;

an access node list acquisition means for acquiring, from said paging agent, the access node list transmitted in response to the request by said access node list requesting means;

an access node address acquisition means for acquiring, from the data link layer, the data link layer address with regard to access nodes existing on said access link, triggered by the establishment of a connection to a link in the data link layer; and

a network layer movement detection means for detecting a default router, based on the data link layer address acquired by said access node address acquisition means and the access-node list acquired by said access node list acquisition means.

4. The mobile host according to claim 3, wherein said access node notification means notifies said paging agent of the information with regard to the address of access nodes existing on said access link, if the communication status has changed from an Active state to a Dormant state, or if an access node on the link located outside the paging area is detected during a Dormant state.

5. The mobile host according to claim 3, wherein said access node notification means notifies said paging agent of the network layer address and the data link layer address with regard to the access router if the access node existing on said access link is composed of an access router, and notifies said paging agent of the network layer address with regard to the access router and the data link layer address with regard to the access point if the access node existing on said access link is composed of an access router and an access point.

6. The mobile host according to claim 3, wherein said access node list requesting means requests said paging agent for transmission of an access node list with regard to access nodes existing on access nodes existing in a paging area in which said mobile host is currently located and access nodes existing on the neighboring link of said paging area.

7. The mobile host according to claim 3, wherein said network layer movement detection means detects a default router from the access node list acquired by said access node list acquisition means, by searching for an access node that matches the data link layer address acquired by said access node address acquisition means.

8. A paging agent for managing the movement status of a mobile host comprising:

an access node acquisition means for acquiring information with regard to the address of access nodes existing on the access link to which said mobile host is connected;

an access node list creating means for creating an access node list from the information acquired by said access node acquisition means; and

an access node list notification means for extracting, from the access node list created by said access node list creating means, the access nodes existing in the proximity of said access link and notifying said access nodes to said mobile host.

9. The paging agent according to claim 8, wherein said access node list notification means notifies the access node list with regard to the address of access nodes existing within the paging area in which said mobile host is located and access nodes existing on the neighboring link of said paging area.

10. The paging agent according to claim 9, wherein said access node acquisition means acquires, from a mobility anchor point which manages the local movement of said mobile host, information with regard to the address of access nodes existing on the access link to which said mobile host is connected.

11. A packet communication system comprising a mobile host and a paging agent for managing the movement status of said mobile host, wherein

said mobile host comprises:

an access node notification means for notifying the information with regard to the address of access nodes existing on the access link to which said mobile host is connected, to a paging agent which manages the movement status of said mobile host;

an access node list requesting means for requesting said paging agent for transmission of an access node list which is the address list of the access nodes existing on the neighboring link of said access link;

an access node list acquisition means for acquiring, from said paging agent, the access node list transmitted in response to the request by said access node list requesting means;

an access node address acquisition means for acquiring, from the data link layer, the data link layer address with regard to access nodes existing on said access link, triggered by the establishment of a connection to a link in the data link layer; and

a network layer movement detection means for detecting a default router, based on the data link layer address acquired by said access node address acquisition means and the access node list acquired by said access node list acquisition means,

and said paging agent comprises;

an access node acquisition means for acquiring information with regard to the address of access nodes existing on the access link to which said mobile host is connected;

an access node list creating means for creating an access node list from the information acquired by said access node acquisition means; and

an access node list notification means for extracting, from the access node list created by said access node list creating means, the access nodes existing in the proximity of said access link and notifying said access nodes to said mobile host.

12. A movement detection method for detecting the movement of a mobile host in a packet communication network, comprising:

a communication status detection step in which said mobile host detects that the communication status in the network layer is in a Dormant state;

a data link layer connection establishment notification step in which said mobile host notifies the network layer that a connection to a link is established in the data link layer if it is detected that the communication status is in a Dormant state in said communication status detection step; and

a network layer movement detection step in which said mobile host, triggered by the notification from said data link layer connection establishment notification step, detects a default router.

13. A movement detection method for detecting the movement of a mobile host in a packet communication network, comprising:

an access node notification step in which said mobile host notifies the information with regard to the address of access nodes existing on the access link to which said mobile host is connected, to a paging agent which manages the movement status of said mobile host;

an access node list requesting step in which said mobile host requests said paging agent for transmission of an access node list which is the address list of the access nodes existing on the neighboring link of said access link;

an access node list acquisition step in which said mobile host acquires, from said paging agent, said access node list transmitted in response to the request made in said access node list requesting step;

an access node address acquisition step in which said mobile host acquires, from the data link layer, the data link layer address with regard to access nodes existing on said access link, triggered by the establishment of a connection to a link in the data link layer; and

a network layer movement detection step in which said mobile host detects a default router, based on the data link layer address acquired in said access node address acquisition step and the access node list acquired in said access node list acquisition step.

14. A movement detection method for detecting the movement of a mobile host in a packet communication network, comprising:

an access node acquisition step in which a paging agent for managing the movement status of said mobile host acquires information with regard to the address of~ access nodes existing on the access link to which said mobile host is connected;

an access node list creating step in which said paging agent creates an access node list from the information acquired in said access node acquisition step; and

an access node list notification step in which said paging agent extracts, from the access node list created in said access node list creating step, access nodes existing in the proximity of said access link and notifies said access nodes to said mobile host.

15. A movement detection method for detecting the movement of a mobile host in a packet communication network, comprising:

an access node notification step in which said mobile host notifies the information with regard to the address of access nodes existing on the access link to which said mobile host is connected, to a paging agent which manages the movement status of said mobile host;

an access node acquisition step in which said paging agent acquires the information with regard to the address of an access node notified in said access node notifying step;

an access node list creating step in which said paging agent creates an access node list from the information acquired in said access node acquisition step;

an access node list requesting step in which said mobile host requests said paging agent for transmission of an access node list which is the address list of the access nodes existing on the neighboring link of said access link;

an access node list notification step in which said paging agent extracts, from the access node list created in said access node list creating step, access nodes existing in the proximity of said access link and notifies the access nodes to said mobile host, in response to the request made in said access node list requesting step;

an access node list acquisition step in which said mobile host acquires, from said paging agent, said access node list notified in said access node list notification step;

an access node address acquisition step in which said mobile host acquires, from the data link layer, the data link layer address with regard to access nodes existing on said access link, triggered by the establishment of a connection to a link in the data link layer; and

a network layer movement detection step in which said mobile host detects a default router, based on the data link layer address acquired in said access node address acquisition step and the access node list acquired in said access node list acquisition step.