Method and apparatus for supporting mobile communications in asynchronous transfer mode based networks

• US 5,487,065 A
• Filed: 03/04/1994
• Issued: 01/23/1996
• Est. Priority Date: 05/26/1993
• Status: Expired due to Fees

• Current Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Original Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Inventors: Naghshineh, Mahmoud, Acampora, Anthony S.
• Primary Examiner(s): Chin, Wellington
• Application Number:
  US08/206,443
• Time in Patent Office: 690 Days
• Field of Search: 370/60.1, 370/94.2, 370/94.3, 370/95.1, 370/16, 370/58.1, 370/58.2, 370/58.3, 370/110.1, 370/60, 370/94.1, 340/825.02, 340/825.03, 340/827, 379/58, 379/59, 379/60, 379/63, 379/220, 379/221
• US Class Current: 370/331
• CPC Class Codes: H04L 2012/5607 Radio
• CPC Class Codes: H04L 2012/5619 Network Node Interface, e.g. tandem connections, transit switching
• CPC Class Codes: H04L 49/3081 ATM peripheral units, e.g. policing, insertion or extraction
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/12 Reselecting a serving backbone network switching or routing node
• CPC Class Codes: H04W 40/36 due to handover
• CPC Class Codes: H04W 76/20 Manipulation of established connections

Abstract

Distributed call setup and rerouting are realized in a mobile-communications network. A connection tree is set up within the network, e.g., upon a mobile user accessing a base station. The connection tree comprises communication routes from a fixed point in the network, the root of the tree, to each base station within a vicinity of the base station accessed by the mobile user. When the mobile user moves from one cell to another within the connection tree, the call is rerouted to another route within the connection tree.

Claims

1. A mobile-communications connection-and-routing method comprising the steps of:

detecting an attempted mobile communication in the vicinity of a first base station in a network comprising a plurality of switches, communication links and base stations, each base station corresponding to a geographical cell;

setting up a connection tree within the network, the connection tree comprising a plurality of communication routes, each route extending from a first switch within the network through at least one other switch and at least two communication links to a base station, each base station situated within a predetermined distance of the first base station, so that a route is defined from each of the base stations within the predetermined distance to the first switch;

setting up a fixed route within the network which extends from the first switch to a location within the network and outside of the connection tree;

providing the first switch with first routing information from the first switch to the connection tree and with second routing information from the first switch to the location within the network and outside of the connection tree;

admitting the communication to the connection tree; and

routing the communication through a first route between the first base station and the first switch, the first route being one of the plurality of communication routes within the connection tree, and between the first switch and the location outside of the connection tree through the fixed route, whereby the mobile user can communicate back and forth along a complete communication route with the location outside of the connection tree;

further comprising, at the first switch and upon a communication from the connection tree to the location within the network and outside of the connection tree, the steps of;

storing a virtual channel identifier,

identifying a current base station,

determining whether the identified current base station differs from a previously identified base station, and, in case of difference,

replacing the first routing information with new first routing information from the first switch to the connection tree.

2. A mobile-communications connection-and-routing method comprising the steps of:

detecting an attempted mobile communication in the vicinity of a first base station in a network comprising a plurality of switches, communication links and base stations, each base station corresponding to a geographical cell;

setting up a connection tree within the network, the connection tree comprising a plurality of communication routers, each route extending from a first switch within the network through at least one other switch and at least two communication links to a base station, each base station situated within a predetermined distance of the first base station, so that a route is defined from each of the base stations within the predetermined distance to the first switch;

providing the first switch with first routing information from the first switch to the connection tree and with second routing information from the first switch to the location within the network and outside of the connection tree;

admitting the communication to the connection tree; and

routing the communication through a first route between the first base station and the first switch, the first route being one of the plurality of communication routes within the Connection tree, and between the first switch and a second base station within the predetermined distance of the first base station through a second route, the second route being one of the plurality of communication routes within the connection tree, whereby the mobile user can communicate back and forth along a complete communication route with the second base station within the connection tree;

further comprising, at the first switch and upon a communication from the connection tree to the location within the network and outside of the connection tree, the steps of;

storing a virtual channel identifier,

identifying a current base station,

determining whether the identified current base station differs from a previously identified base station, and, in case of difference,

replacing the first routing information with new first routing information from the first switch to the connection tree.

3. A connection-and-routing method for mobile communications in a network comprising base stations, switching nodes, and communication links, each one of the base stations corresponding to a geographical cell, the method comprising:

determining a communication route within the network, the connection route connecting a first one of the base stations to a first one of the switching nodes by a first portion of the communication route, and the connection route connecting the first one of the switching nodes further by a second portion of the communication route, the first one of the base stations being within communication range of a mobile user,

determining a connection tree within the network, the connection tree comprising the first portion of the connection route and at least one potential first portion of the communication route within the network, the at least one potential first portion connecting a second one of the base stations to the first one of the switching nodes,

providing the first switch with first routing information from the first switch to the connection tree and with second routing information from the first switch to the location within the network and outside of the connection tree;

admitting the communication to the connection tree; and

routing the communication through a first route between the first base station and the first switch, the first route being one of the plurality of communication routes within the connection tree, and between the first switch and the location outside of the connection tree through the fixed route, whereby the mobile user can communicate back and forth along a complete communication route with the location outside of the connection tree;

further comprising, at the first switch and upon realization of a predetermined condition depending on movement of the mobile user, the steps of;

storing a virtual channel identifier,

identifying a current base station,

determining whether the identified current base station differ is from a previously identified base station, and, in case of difference,

replacing the first routing information with new first routing information from the first switch to the connection tree.

4. A system for mobile-communications connection and routing comprising:

a network comprising a plurality of switches, communication links and base stations capable of supporting asynchronous transfer mode communications;

means for detecting an attempted mobile communication in the vicinity of a first base station in the network;

means for setting up a connection tree within the network, the connection tree comprising a plurality of communication routes, each route extending from a fixed point of the network, the fixed point being a switch, through at least one other switch and at least three communication links to all base stations within a predetermined distance of the first base station so that a route is defined from each of the base stations within the predetermined distance to the fixed point switch;

means for setting up a fixed route within the network which extends from the fixed point switch to a desired destination within the network and outside the connection tree;

means for admitting the communication to the connection tree at the first base station; and

means for routing the communication from the first base station through a first route, which is one of the plurality of communication routes within the connection tree, to the fixed point, and from the fixed point through the fixed route to the destination, whereby the mobile user can communicate back and forth with the destination;

further comprising, at the first switch;

means for storing a virtual channel identifier,

means for identifying a current base station,

means for determining whether the identified current base station differs from a previously identified base station, and, in case of difference,

means for replacing the first routing information with new first routing information from the first switch to the connection tree.

5. A system for mobile-communications connection and routing comprising:

means for detecting an attempted mobile communication in the vicinity of a first base station in a network comprising a plurality of switches, communication links and base stations, each base station corresponding to a geographical cell;

means for setting up a connection tree within the network, the connection tree comprising a plurality of communication routes, each route extending from a first switch within the network through at least one other switch and at least two communication links to a base station, each base station situated within a predetermined distance of the first base station, so that a route is defined from each of the base stations within the predetermined distance to the first switch;

means for admitting the communication to the connection tree; and

means for routing the communication through a first route between the first base station and the first switch, the first route being one of the plurality of communication routes within the connection tree, and between the first switch and a second base station within the predetermined distance of the first base station through a second route, the second route being one of the plurality of communication routes within the connection tree, whereby the mobile user can communicate back and forth along a complete communication route with the second base station within the connection tree;

further comprising;

means for initiating a change of the mobile user'"'"'s base station from the first base station to a third base station upon the mobile user moving from the cell corresponding to the first base station to the cell corresponding to the third base station, the third base station corresponding to a third route which is one of the plurality of communication routes within the connection tree and which connects the third base station to the first switch; and

means for changing the first route portion of the complete communication route from the first route to the third route, comprising, at the first switch;

means for storing a virtual channel identifier,

means for identifying a current base station,

means for determining whether the identified current base station differs from a previously identified base station, and, in case of difference,

means for replacing the first routing information with new first routing information from the first switch to the connection tree.