Multi-Stage Network Architecture Reducing Crosspoint Complexity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multi-stage networks with radices greater than two face significant challenges in implementing nonblocking multicast connections due to prohibitively large crosspoint complexity, particularly in field programmable gate array (FPGA) devices and digital crossconnects, where existing designs are inefficient and hard to implement.
Innovation Solution
A multi-stage network architecture with (2×logd N)−1 stages, featuring an input stage with Nd switches, an output stage with Nd switches, and (2×logd N)−3 middle stages, each with 2×Nd or 3×Nd switches, depending on the operation mode, allowing for strictly nonblocking unicast and rearrangeably nonblocking multicast connections using optimal link configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multi-stage networks with radices greater than two are implemented, then connection capability is improved, but crosspoint complexity becomes prohibitively large
Solution Approach 1:
The network is divided into multiple stages (input stage, middle stages, output stage) with specific switch configurations. Each stage processes connections independently, segmenting the overall complex switching function into manageable parts that reduce total crosspoint complexity while maintaining radix greater than two for enhanced connection capability.
Solution Approach 2:
Different stages of the network are assigned different switch configurations optimized for their specific functions. The input stage uses Nd switches, middle stages use 2×Nd or 3×Nd switches depending on operation mode, and output stage uses Nd switches. This local optimization allows each stage to contribute to overall connection capability while minimizing its own crosspoint requirements.
2Adaptability or versatility
If nonblocking multicast connections are implemented, then connection flexibility is improved, but implementation difficulty increases significantly
Solution Approach 1:
The network architecture is pre-configured with specific stage structures and switch arrangements that enable nonblocking multicast connections before actual traffic arrives. The input stage with Nd switches and middle stages with 2×Nd or 3×Nd switches are designed in advance to provide the necessary connection flexibility, reducing implementation difficulty during deployment.
Solution Approach 2:
Middle stages act as intermediaries between input and output stages, facilitating multicast connections through carefully designed switch configurations. These intermediate stages with 2×Nd or 3×Nd switches provide the necessary flexibility for nonblocking multicast while simplifying the overall implementation by breaking down the complex switching function into manageable intermediate steps.
Data Source
AI summary
A multi-stage network comprising (2×logd N)−1 stages is operated in strictly nonblocking manner for unicast, also in rearrangeably nonblocking manner for arbitrary fan-out multicast when s≧2 , and is operated in strictly nonblocking manner for arbitrary fan-out multicast when s≧3 , includes an input stage havingNdswitches with each of them having d inlet links and s×d outgoing links connecting to second stage switches, an output stage havingNdswitches with each of them having d outlet links and s×d incoming links connecting from switches in the penultimate stage. The network also has (2×logd N)−3 middle stages with each middle stage havings×Ndswitches, and each switch in the middle stage has d incoming links connecting from the switches in its immediate preceding stage, and d outgoing links connecting to the switches in its immediate succeeding stage. Also each multicast connection is set up by use of at most two outgoing links from the input stage switch.