Network fragmentation measurement in an optical wavelength division multiplexing (WDM) network
View Patent ↗A method implemented in a network apparatus used in a wavelength division multiplexing (WDM) optical network is disclosed. The method includes (a) finding K-shortest routes between each node pair (s, d), where s, dεV and |V|≦K, where V is a set of reconfigurable optical add-drop multiplexer (ROADM) nodes, (b) selecting unconsidered node pair (s, d), (c) selecting unconsidered route k between nodes s and d out of the K-shortest routes, (d) finding a bit map of route k by performing bit-wise logical AND operation on bit vectors of fibers along route k, (e) selecting unconsidered line rate l out of offered set L of line rates, and (f) finding a probability α l s,d,k of provisioning a connection with line rate l. Other apparatuses, systems, and methods also are disclosed.
1. A method implemented in a network apparatus used in a wavelength division multiplexing (WDM) optical network, the method comprising:
(a) finding K-shortest routes between each node pair (s, d), where s, dεV and |V|≦K, where V is a set of reconfigurable optical add-drop multiplexer (ROADM) nodes;
(b) selecting unconsidered node pair (s, d);
(c) selecting unconsidered route k between nodes s and d out of the K-shortest routes;
(d) finding a bit map of route k by performing bit-wise logical AND operation on bit vectors of fibers along route k;
(e) selecting unconsidered line rate l out of offered set L of line rates; and
(f) finding a probability α l s,d,k of provisioning a connection with line rate l.
2. The method as in claim 1 , further comprising:
(g) iterating steps (e) and (f) until all line rates in offered set L are considered.
3. The method as in claim 2 , further comprising:
(h) iterating steps (c) to (g) until all of the K-shortest routes between node pair (s, d) are considered.
4. The method as in claim 3 , further comprising:
(i) iterating steps (b) to (h) until all node pairs are considered.
5. The method as in claim 4 , further comprising:
(j) determining fragmentation factor (FF) according to the following formula:
FF
=
[
1
-
{
1
T
∑
∀
(
s
,
d
)
(
1
K
∑
k
=
1
k
=
K
∑
l
∈
L
(
Q
l
×
α
l
s
,
d
,
k
)
)
}
]
,
where T is granularity at which a spectrum is slotted, and Q l is a probability of requesting line rate l.
6. A wavelength division multiplexing (WDM) optical network comprising:
a network apparatus,
wherein the network apparatus
(a) finds K-shortest routes between each node pair (s, d), where s, de V and |V|≦K, where V is a set of reconfigurable optical add-drop multiplexer (ROADM) nodes,
(b) selects unconsidered node pair (s, d),
(c) selects unconsidered route k between nodes s and d out of the K-shortest routes,
(d) finds a bit map of route k by performing bit-wise logical AND operation on bit vectors of fibers along route k,
(e) selects unconsidered line rate l out of offered set L of line rates, and
(f) finds a probability α l s,d,k of provisioning a connection with line rate l.
7. The WDM optical network as in claim 6 , wherein the network apparatus
(g) iterates steps (e) and (f) until all line rates in offered set L are considered.
8. The WDM optical network as in claim 7 , wherein the network apparatus
(h) iterates steps (c) to (g) until all of the K-shortest routes between node pair (s, d) are considered.
9. The WDM optical network as in claim 8 , wherein the network apparatus (i) iterates steps (b) to (h) until all node pairs are considered.
10. The WDM optical network as in claim 9 , wherein the network apparatus
(j) determines fragmentation factor (FF) according to the following formula:
FF
=
[
1
-
{
1
T
∑
∀
(
s
,
d
)
(
1
K
∑
k
=
1
k
=
K
∑
l
∈
L
(
Q
l
×
α
l
s
,
d
,
k
)
)
}
]
,
where T is granularity at which a spectrum is slotted, and Q l is a probability of requesting line rate l.