PCEP RWA Computation for WDM Network Contention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wavelength division multiplexing (WDM) networks face challenges in determining routing and wavelength assignment (RWA) due to the constraint of ensuring different wavelengths are not used simultaneously over a single fiber, compounded by the finite number of usable optical wavelengths, which complicates the implementation of wavelength switched optical networks.
Innovation Solution
The method extends the Path Computation Element Protocol (PCEP) to accommodate RWA in WDM networks by allowing a Path Computation Client (PCC) to request and receive routing and wavelength assignments, including bidirectional and simultaneous assignments for primary and backup lightpaths, with optical transmitter tuning range constraints, using a request parameter object that includes a routing and wavelength assignment computation flag.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If wavelength assignment is performed sequentially for each lightpath, then the complexity of wavelength assignment is reduced, but the contention for wavelengths increases and network performance deteriorates
Solution Approach 1:
The patent applies preliminary action by performing wavelength assignment for multiple lightpaths simultaneously in a centralized manner, rather than sequentially. The PCE computes wavelength assignments for all lightpaths in advance based on global network state, preventing wavelength contention before it occurs and improving overall network performance.
2Device complexity
If routing and wavelength assignment are performed as separate independent processes, then the computation complexity is reduced, but the coordination between routing and wavelength assignment becomes more difficult
Solution Approach 1:
The patent merges routing computation and wavelength assignment into a single integrated RWA computation process performed by the PCE. This unified approach allows simultaneous determination of routes and wavelengths, ensuring proper coordination between the two functions while maintaining manageable computation complexity through centralized processing.
3Quantity of substance
If the number of usable optical wavelengths is increased, then the bandwidth capability is improved, but the constraint of wavelength collision detection becomes more complex
Solution Approach 1:
The patent implements feedback mechanisms where the PCE receives wavelength availability information from network elements and uses this feedback to compute optimal wavelength assignments. The PCE continuously monitors network state and adjusts wavelength assignments accordingly, making collision detection manageable even as the number of wavelengths increases.
Data Source
Figure 1
Figure 2~4
Figure 5~6
AI summary
A network component comprising at least one processor configured to implement a method comprising transmitting a request to compute a routing assignment, a wavelength assignment, or both, wherein the request comprises a lightpath constraint indicator is disclosed. Also disclosed is an apparatus comprising a Path Computation Client (PCC) configured to transmit a request to and receive a reply from a Path Computation Element (PCE), wherein the request comprises a lightpath constraint, and wherein the reply comprises a routing assignment, a wavelength assignment, an error message, a no-path indication, or combinations thereof. Included is a method comprising receiving a request comprising a request parameter (RP) object comprising a lightpath constraint, sending a reply comprising a routing assignment, a wavelength assignment, an error message, a no- path indicator, or combinations thereof, wherein the request is received and the reply is sent using path computation element protocol (PCEP).