In EON(elastic optical system), fragmentation of lightpath is one primary concern. A few methodologies have been introduced. The paths (i.e. Backup and Primary) available for EON. This liberates the lightpaths to be partitioned into parts are induced by primary lightpaths, which are not to be disturbed to accomplish hitless defragmentation. We trade path function work by flipping the ways. This permits lightpaths to be reallocated amid the defragmentation procedure while they function as backup. For changing path function, we show static spectrum reallocation optimization that overcomes spectrum fragmentation.

1. A
Synopsis Report
On
Exchanging Path Function with 1+1 path protected Elastic
Optical Network(EON)
Or
Dynamic fragmentation using path exchange scheme in EON
Abstract : In EON(elastic optical system), fragmentation of lightpath is one primary concern. A
few methodologies have been introduced. The paths (i.e. Backup and Primary) available for EON.
This liberates the lightpaths to be partitioned into parts are induced by primary lightpaths, which
are not to be disturbed to accomplish hitless defragmentation. We trade path function work by
flipping the ways. This permits lightpaths to be reallocated amid the defragmentation procedure
while they function as backup. For changing path function, we show static spectrum reallocation
optimization that overcomes spectrum fragmentation. We demonstrated issue of static spectrum
reallocation is NP -complete. We presented an algorithm where ILP problem is not easily find out.
Keywords—Elastic optical networks, hitless defragmentation, 1+1 path protection, path
exchanging

2. I. INTRODUCTION
Spectrum fragmentation is one of primary concern. The connection are to be added or terminated,
the spectrum resources utilized by terminated connection to be reallocated. Small blocks to be
scattered these are not available in contiguous link. This is spectrum Fragmentation. To defeat the
issue a few defragmentation approaches have been displayed. The creators demonstrate that
keeping away from spectrum fragmentation is availability of large slot blocks and alignment
through consecutive link. To accomplish that, both preventive and receptive methodologies have
been considered. A hitless defragmentation approach works ceaselessly in EONs without service
disruption. Spectrum retuning is being used to achieve hitless defragmentation. With spectrum
retuning, lightpaths are retuned and moved to fill holes left, either by push-pull retuning [4] or
bounce retuning. Link failures is another challenge for EON. Optical systems carry huge data
which leads to data loss The author introduced a 1+1path protection defragmentation approach in
EONs. Their focus is set on the defragmentation advantage offered by the backup paths.. They
consider that, corresponding primary path, they can be reallocated and/or rerouted for
defragmentation purposes without causing any traffic disruption. In this way, the authors
accomplish hitless defragmentation by performing spectrum retuning.
Background
Traffic request on network increases rapidly. EON has been developed for handling incoming
traffic request. The ITU-T frequency has already reached its limit above 100 GB/s Rate and EONs
can accommodate traffic rates above the 100 GB/s rate with various modulation level. EON
flexible frequency allocations it allocates only the needed bandwidth for traffic demand. With
connection being included and ended, EONs, the spectrum resources previously utilized by
terminated connections are to be reallocated to new requests. Because of the alignment and
consecutiveness constraints of EON routing and (RSA) problem, spectrum fragmentation leads to
requests being blocked, and hence leads to reduced traffic admissibility. The RSA problem is,
given a set of traffic demands, the problem of setting up lightpaths by routing and allocating the
necessary spectrum (required sub-wavelengths) to each traffic demand.
Motivation:
Because of increasing traffic on a node a fragmentation becomes main issue for such dynamic
traffic. Other subtopic on handling dynamic traffic will not clearly mentioned the technical things.
This paper gives detail explanation about such things.

3. Goals and objectives:
1) Toggling primary to backup path and vice versa using path exchanging scheme to achieve
hitless defragmentation rather than spectrum retuning.
2) Performing spectrum defragmentation process for dynamic process where ILP problem is not
traceable.
II. EXISTING SYSTEM
A Path Exchanging in 1+1 path protection
We consider a 1+1 path protection scenario to offer protection against link failures. With 1+1 path
protection, each established signal is duplicated and both signals are transmitted to the destination
through disjoint paths. This allows the receiver to select the incoming data from any of the two
signals. Thus, if one path suffers link failure or is disconnected, the data reception is continued
through the other path.
B. Hitless Defragmentation with Exchanging Paths
The proposed scheme is able to achieve hitless defragmentation on 1+1 path protected networks
without requiring any additional equipment. We take advantage of the availability of a by default
alternate signal to reallocate lightpaths considering spectrum fragmentation. Since the data is being
received through the primary paths, we can afford to reallocate the signals of backup paths during
the defragmentation process without disrupting the data transmission. The defragmentation is
performed without traffic disruption, provided that no failure occurs on a primary path while its
corresponding backup path is being reallocated. In terms of eliminating spectrum fragmentation,
the advantage of the proposed scheme is to be able to reallocate both paths of the 1+1 protection
for hitless defragmentation without restriction. With the conventional designated primary and
backup paths where data from backup paths are used only if there is some impediment on the
corresponding primary paths, only backup paths can be reallocated in a hitless defragmentation
C Defragmentation Approach Using Path Exchanging Scheme
With the aim to allow maximum traffic load in 1+1 path protected EONs, the proposed paths
exchanging scheme is applied. It reduces the blocking probability by minimizing the spectrum
fragmentation. The way the proposed scheme is applied depends on the traffic pattern. With static
traffic loads, the spectrum state does not change often overtime, but with dynamic traffic loads,
the spectrum is in constant evolution. In the case of static traffic load, spectrum fragmentation can
be avoided by network planning, and the optimization problem is used in the rare occasions where
changes are needed including the cases of network extensions and reconfigurations. On the other
hand, for dynamic traffic loads where lightpaths can be added or removed at any moment, the

4. spectrum has to be defragmented frequently in order to avoid requests being blocked due to
fragmentation. In the following, we focus on dynamic traffic loads.
Advantages Of Existing System
1) A hitless defragmentation can be achieved.
2) Spectrum fragmentation which is main issue can be removed using path exchanging scheme
3) Because of toggling primary path to backup path and vice versa the data in EON can be
protected using mixed primary and backup path algorithm.
III. PROPOSED SYSTEM
Static Path Exchanging Optimization
1.Objective:
We consider static spectrum fragmentation. For a lightpath to be reallocated we are arranging
lightpath to be reallocated to minimize spectrum fragmentation. We use path exchanging scheme
to minimize spectrum fragmentation .We limit network operation to stop repetitive
defragmentation process .With more request of lightpath, this lead to serious problem of bandwidth
blocking. So we limit the number of requested lightpath.
2.Optimization Problem:
While limiting the request we consider SRR problem between initial and target state We note that
target spectrum set by SSR problem, this minimizes the target spectrum state at given instance.
To overcome this concern, we consider to define a problem formulation that combines the SSR
problem to minimize the spectrum fragmentation and the transition problem to limit the network
operations into a single problem. For the remaining of this paper, we refer to this problem as the
static spectrum reallocation for limited network operations (SSR-LNO) problem.
3.Transition Using Path Exchange
Solving the SSR-LNO problem returns the target spectrum state with reduced fragmentation and
limited number of path exchanging and backup reallocation operations during the transition
process. Suppose that a target spectrum state is given, we consider how the initial state is moved
to the target state by applying the path exchanging scheme
IV. CONTRIBUTION
The data is at backup path by switching path from primary to backup which is then fragmented
after the data reaches from destination node. The paper proposes fragmentation of data only when
data reached after the all the data reached at destination. If we are performing fragmentation of
data along with receiving of lightpath, this phenomenon will save our time. Also it is added
advantage when we have to fragment huge amount data at backup side, so there is no need to wait

5. to receive all the data at destination side. This defragmentation is performed without traffic
disruption, provided that no failure occurs on a backup path while its corresponding backup path
is being reallocated with reaching of data from client side. Sending of data is carried out along
with reallocation of lightpath automatically.
V. ALGORITHM
Mixed Primary and Backup Path Algorithm:
Algorithm for dynamic spectrum defragmentation, which is called a mixed primary and backup
(MPB) algorithm (see algorithm 1), consists of three steps:
(i) Sort all the lightpaths, in a single list, according to a policy,
(ii) Proceed to the first defragmentation stage by reallocating lightpaths following the
sorted list,
(iii) Refine the defragmentation by reallocating lightpaths that can be pushed further down.
Algorithm Steps
Input: Spectrum, active signals
Output: Defragmented spectrum
Step 1: Sort all lightpaths according to policy
Step 2: First stage defragmentation
2.1: Select the lightpath at the top of the sorted list,
2.2: Select other lightpaths that can be reallocated in
parallel with the first selected lightpath, following
the sorted list,
2.3: Reallocate selected lightpaths using the exact-fit
policy. If primary path toggle first,
2.4: Remove selected lightpaths from the list,
2.5: Repeat from 2.1, until all lightpath are selected.
Step 3: Refining defragmentation
3.1: Initialize pointer at index 0,
3.2: Increment pointer,
3.3: Reallocate selected lightpaths p using the exact-fit
policy. If p is a primary, then first toggle p.

6. 3.3: Repeat from 3.2, until the highest allocation index
is reached.
X RESULTS
From the above three mentioned scheme we achieved that the defragmentation technique is useful
when there will be the huge amount of lightpath request coming at client side Also, additionally it
will be helpful over bandwidth blocking where blocking probability reduced by path exchanging
scheme and adding lightpath dynamically. There is an added advantage that fragmenting the data
at backup side along with receiving the data , it will save our time rather waiting to be data received
at client side. The RSA problem can be solvable using the 1+1 path protection scheme in dynamic
spectrum fragmentation where the ILP problem is not traceable. The automatic fragmentation at
backup path is done for time saving purpose we increase our performance probability upto 10%
additionally. From above all method we proved that for huge amount of request to be carried at
client side we do not require any extra hardware , we use some allocation scheme and achieve the
desired result.
Conclusion
This paper has proposed a defragmentation scheme utilizing essential and reinforcement ways
trading in 1+1 way ensured EONs to enhance activity acceptability. The proposed scheme change
the function of lightpaths in a 1+1 path protection from primary to backup path on the other hand
to allow initially primary lightpaths to be reallocated for defragmentation .The proposed scheme
also offers a hitless defragmentation by path exchanging. We have defined an optimization
problem of the static spectrum reallocation with limited network operations (SSR-LNO), which
minimizes the spectrum fragmentation, and formulated it as an ILP problem We have
demonstrated that the SSR-LNO is NP-complete. We have displayed a range defragmentation
approach for dynamic EONs, and presented a heuristic calculation tractable for vast systems. The
reproduction comes about propose that the presented heuristic calculation offers blocking
exhibitions tantamount to the ones acquired utilizing the ILP approach. The proposed path
exchanging scheme outperforms the conventional scheme with designated primary and backup
paths, with up to 10% additional admissible traffic when the processing speed is considered.

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