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

• US 5,590,125 A
• Filed: 06/05/1995
• Issued: 12/31/1996
• 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: Acampora, Anthony S., Naghshineh, Mahmoud
• Primary Examiner(s): Chin, Wellington
• Application Number:
  US08/460,914
• Time in Patent Office: 575 Days
• Field of Search: 370/95.1, 370/95.3, 370/94.1, 370/94.2, 370/60, 370/60.1
• US Class Current: 370/397
• 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

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 method of routing asynchronous transfer mode mobile communications comprising the steps of:

receiving a packet comprising a packet header, which in turn comprises an input virtual channel identifier for the packet, at a first input port of a multiport switch, the switch having a virtual channel identifier comparator at each input port, each comparator having read/write access to a routing lookup table which contains rows of routing information, each of the rows of routing information comprising an input virtual channel identifier, an input port, an output virtual identifier and an output port;

reading the input virtual channel identifier from the packet header;

comparing the input virtual channel identifier read from the packet header with the input virtual channel identifiers contained in the routing lookup table; and

enabling first and second rows of routing information within the routing lookup table, the first row of routing information comprising the output virtual channel identifier and output port which will be assigned to the packet which will be routed to the destination of the mobile user'"'"'s communication and the second row of routing information comprising the output virtual channel identifier and output port which will be assigned to incoming packets received at a second input port to be routed to the mobile user.

2. A method of routing asynchronous transfer mode mobile communications comprising the steps of:

reading a control message at a multiport ATM switch having a reroute port and a routing lookup table which contains rows of routing information, each of the rows of routing information comprising an input virtual channel identifier, an input port, an output virtual identifier and an output port, the control message comprising a mobile user'"'"'s connection tree ID and base station address; and

enabling first and second rows of routing information within the routing lookup table, the first row of routing information comprising the output virtual channel identifier and output port which will be assigned to the packet which will be routed to the destination of the mobile user'"'"'s communication and the second row of routing information comprising the output virtual channel identifier and output port which will be assigned to incoming packets received at a second input port to be routed to the mobile user.

3. A system for routing asynchronous transfer mode mobile communications comprising:

means for receiving a packet comprising a packet header, which in turn comprises an input virtual channel identifier for the packet, at a first input port of a multiport switch, the switch having a virtual channel identifier comparator at each input port, each comparator having read/write access to a routing lookup table which contains rows of routing information, each of the rows of routing information comprising an input virtual channel identifier, an input port, an output virtual identifier and an output port;

means for reading the input virtual channel identifier from the packet header;

means for comparing the input virtual channel identifier read from the packet header with the input virtual channel identifiers contained in the routing lookup table; and

means for enabling first and second rows of routing information within the routing lookup table, the first row of routing information comprising the output virtual channel identifier and output port which will be assigned to the packet which will be routed to the destination of the mobile user'"'"'s communication and the second row of routing information comprising the output virtual channel identifier and output port which will be assigned to incoming packets received at a second input port to be routed to the mobile user.

4. A system for routing asynchronous transfer mode mobile communications comprising:

means for reading a control message at a multiport ATM switch having a reroute port and a routing lookup table which contains rows of routing information, each of the rows of routing information comprising an input virtual channel identifier, an input port, an output virtual identifier and an output port, the control message comprising a mobile user'"'"'s connection tree ID and base station address; and

means for enabling first and second rows of routing information within the internal lookup table, the first row of routing information comprising the output virtual channel identifier and output port which will be assigned to the packet which will be routed to the destination of the mobile user'"'"'s communication and the second row of routing information comprising the output virtual channel identifier and output port which will be assigned to incoming packets received at a second input port to be routed to the mobile user.