Wavelength bypassed ring networks
First Claim
1. An optical wavelength bypassed ring network (WBRN) configured with a plurality (N) of traffic nodes and a transmission medium chaining from traffic node to traffic node in a ring configuration, a span Sn of said transmission medium for linking a node (n) with a downstream node (n+1), where n is the sequential position of said node (n) in said ring and nε
- 1, N!, each said node (n) comprising;
an input port for receiving a first set of (Qi) incoming channels;
an output port for providing a second set of (Qo) outgoing channels; and
bypass means for directly connecting an incoming channel of said first set having the carrier wavelength λ
q, where qε
1, Q!, to an outgoing channel of said second set, having same carrier wavelength λ
q, for bypassing said node (n) whenever said node (n) is not the destination node for said incoming channel.
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Accused Products
Abstract
The invention is directed to the use of wavelength channels to bypass nodes in ring networks. For networks with a small number of nodes, direct node to node routes are provided without changing the physical layout of the fibre in the ring. Architectures providing complete transparent interconnections with extra capacity for heavily used routes on a portion of the ring are disclosed. For networks with a large number of nodes, underconnected networks provide a number of accelerated, direct routes between some of the nodes. Proposed architectures for underconnected networks and methods for self-routing the traffic are also provided.
58 Citations
22 Claims
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1. An optical wavelength bypassed ring network (WBRN) configured with a plurality (N) of traffic nodes and a transmission medium chaining from traffic node to traffic node in a ring configuration, a span Sn of said transmission medium for linking a node (n) with a downstream node (n+1), where n is the sequential position of said node (n) in said ring and nε
- 1, N!, each said node (n) comprising;
an input port for receiving a first set of (Qi) incoming channels; an output port for providing a second set of (Qo) outgoing channels; and bypass means for directly connecting an incoming channel of said first set having the carrier wavelength λ
q, where qε
1, Q!, to an outgoing channel of said second set, having same carrier wavelength λ
q, for bypassing said node (n) whenever said node (n) is not the destination node for said incoming channel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
- 1, N!, each said node (n) comprising;
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14. A method for routing traffic in an optical ring network configured with a plurality (N) of traffic nodes and a transmission medium connecting said traffic nodes in a ring configuration, a span Sn of said transmission medium for linking a node (n) with a downstream node (n+1), where n is the sequential position of said node (n) in said ring and nε
- 1,N!, said method comprising the steps of;
determining the number of channels necessary for connecting all nodes of said WBRN to each other; providing Q transmission channels along each span Sn, each transmission channel having a distinct wavelength λ
q, where Q=N(N-1)/2 and qε
1,Q!;assigning a first subset (C) of transmission channels λ
c to each said node (n), that terminate at said node, such that C=N-1;at each node (n) adding a second subset of (C) direct single-hop routes, a direct route (R) for connecting said node (n) to a destination node (p) identified by the wavelength λ
c, said direct route (R) comprising one of a direct transmission channel and a by-passing transmission channel, a by-passing transmission channel travelling transparently through all nodes along the section of said ring comprised between said node (n) and said destination node (p), where pε
1,N!; andtransporting a protocol data unit between any node (n) and any destination node (p) of said ring network using said single-hop route. - View Dependent Claims (15)
- 1,N!, said method comprising the steps of;
-
16. A method for routing traffic in an optical ring network configured with a plurality (N) of traffic nodes and an optical fiber chaining from traffic node to traffic node in a ring configuration, a fiber span Sn for linking a node (n) with a downstream node (n+1), where n is the sequential position of said node (n) in said ring and nε
- 1,N!, said method comprising the steps of;
selecting a subset (P) of destination nodes (p), where (p) takes sequential integer values from 1 to P, and P<
N-1;providing Q transmission channels along each fiber span Sn, each transmission channel having a distinct wavelength λ
q, where qε
1,Q!;assigning a subset (C) of transmission channels λ
c to each said node (n), such that C<
N-1;at each node (n), providing (C) direct routes, a direct route (R) for connecting said node (n) to an intermediate node (j), said direct route (R) comprising one of a direct transmission channel λ
c and a by-passing transmission channel λ
c, a by-passing transmission channel travelling transparently along all nodes along the section of said ring comprised between said node (n) and said intermediate node (j; andtransporting a protocol data unit (PDU) between any node (n) and any destination node (p) using a plurality of direct routes. - View Dependent Claims (17, 18, 19)
- 1,N!, said method comprising the steps of;
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20. A traffic node for use in an optical wavelength bypassed ring network (WBRN) configured with a plurality (N) of such traffic nodes in a ring configuration, where n is the sequential position of said node (n) in said ring and nε
- 1, N!, node (n) comprising;
an input port for receiving (Qi) incoming channels and separating same into a first subset of drop channels and a third subset of passthrough channels according to their wavelength; an output port for providing (Qo) outgoing channels including a second subset of locally generated channels and said third subset of passthrough channels; and bypass means for directly connecting said third subset of passthrough channels from said input port to said output port, where Qi and Qo ≧
2. - View Dependent Claims (21)
- 1, N!, node (n) comprising;
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22. A method of routing traffic in an optical ring network configured with a plurality (N) of traffic nodes in a ring configuration, where n is the sequential position of said node (n) in said ring and nε
- 1, N!, said method comprising the steps of;
providing a set of transmission channels of different wavelengths; assigning a distinct first subset of drop channels and a distinct second subset of add channels to each said node (n) for carrying traffic between particular nodes of the network; and connecting said node (n) with a destination node (p) along one of a direct route and a bypass route, a bypass route bypassing all intermediate nodes between said node (n0 and said none (p).
- 1, N!, said method comprising the steps of;
Specification