Dynamic, asymmetric rings

Abstract

Dynamic, asymmetric rings and related communication equipment and methods are disclosed. Various features may be implemented to provide any or all of several degrees of freedom for managing resources in a communication network. Communication rates may be optimized on a node-to-node basis or overall on a network level. Different rates may be configured and possibly dynamically adjusted between different nodes, and/or for different directions of traffic transfer. Bandwidth can be dynamically allocated along a string of the communication nodes in a ring or linear topology in some embodiments. Direction of traffic transfer represents an additional possible degree of freedom in a ring topology, in that traffic can be transferred in either direction in a ring, such as the direction of least delay.

We claim: 
     
         1 . A communication node comprising:
 at least one interface that enables the communication node to exchange communication traffic with adjacent communication nodes in a ring topology; and   a communication control module, operatively coupled to the at least one interface, that enables respective communication rates between the communication node and each of the adjacent communication nodes to be set to different rates for opposite directions of traffic flow in the ring topology.   
     
     
         2 . The communication node of  claim 1 , wherein the communication rate between the communication node and each adjacent communication node comprises a respective rate for each direction of traffic flow, and wherein the communication control module enables dynamic adjustment of a ratio of the respective rates. 
     
     
         3 . The communication node of  claim 2 , wherein the communication control module collects rate information from the adjacent communication nodes, and determines adjusted ratios based on the collected rate information. 
     
     
         4 . The communication node of  claim 3 , wherein the communication control module determines whether an adjusted ratio differs from a current ratio by at least a threshold amount, and applies the adjusted ratio where the adjusted ratio differs from the current ratio by at least a threshold amount. 
     
     
         5 . The communication node of  claim 2 , wherein the communication control module collects information from the adjacent communication nodes and determines adjusted ratios based on the collected information. 
     
     
         6 . The communication node of  claim 1 , wherein the communication control module implements a dynamic rate adjustment algorithm, and allows the dynamic rate adjustment algorithm to be enabled or disabled. 
     
     
         7 . The communication node of  claim 1 , implemented in a communication system that further comprises a plurality of communication nodes, including the adjacent communication nodes, that are interconnected in the ring topology, each of at least one of the plurality of communication nodes comprising:
 at least one interface that enables the communication node to exchange communication traffic with adjacent communication nodes in the ring topology; and   a communication control module, operatively coupled to the at least one interface, that enables respective communication rates between the communication node and each of its adjacent communication nodes to be set to different rates for opposite directions of traffic flow in the ring topology.   
     
     
         8 . A method comprising:
 providing for exchange of communication traffic between a communication node and adjacent communication nodes in a ring topology; and   setting respective communication rates between the communication node and each of the adjacent communication nodes to different rates for opposite directions of traffic flow in the ring topology.   
     
     
         9 . A network comprising:
 a plurality of communication nodes; and   a plurality of communication links operatively coupling the communication nodes together in a ring or linear topology, each communication node comprising a communication control module that enables respective total communication rates between the plurality of communication nodes to be set to different rates between different communication nodes.   
     
     
         10 . The network of  claim 9 , wherein each communication node supports an ADM (Add/Drop Multiplexer) function. 
     
     
         11 . The network of  claim 9 , wherein the communication links enable the communication nodes to communicate via DSL (Digital Subscriber Line) communications. 
     
     
         12 . The network of  claim 11 , wherein the DSL communications are of a type selected from a group consisting of: ADSL (Asynchronous DSL), ADSL2+, SDSL (Symmetric DSL), Uni-DSL (Universal DSL), VDSL (Very high bit rate DSL), and VDSL2 (Very high bit rate DSL version 2).