الفهرس 
CHAPTER I: INTRODUCIONOnly 14 pages are availabe for public view
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Abstract
Optical networks seem to have the answers for all problems in various
networking configurations. They provide end-to-end optical channel or
lightpath to the users. Using Wavelength Division Multiplexing (WDM), up
to 160 (and more) separate wavelengths of data can be multiplexed into a
light stream transmitted on a single optical fiber between two network nodes.
Communication via switching circuit in WDM implies that there is a
dedicated lightpath between the source and the destination. This lightpath is a
connected sequence of dedicated wavelengths on each link between the
source and the destination nodes. Assuming that the network does not have
wavelength conversion capabilities, the same wavelength must be available
on all links belonging to the selected route. Routing and wavelength
assignment (RWA) algorithms usually include a description of a procedure
for finding a route and selecting a wavelength to be used from the set of
available wavelengths along that route. The type of the RWA solution to the
problem depends on the type of network traffic. The network traffic forces the
network manager using either static or dynamic algorithms. Static algorithms
requires the whole requested data and the needed job to be defined before it
starts finding a route or a light path and when starts finding the solution it
finishes, supplies a complete light path to the destination. Dynamic algorithms
receive the data in pieces and deal with it part by part and process it step by
step, recommend the light path segment by segment so that their process is
going dynamically in progress.
In WDM networks, a connection must be established along a route using a
specific wavelength on all of the links along the route. The introduction of
wavelength converters into WDM cross connects increases the hardware cost
and complexity. Given a set of connection requests, the routing and
wavelength assignment problem involves finding a route (routing) and assigning a wavelength to each request. In this thesis, a presentation of the
RWA solutions to WDM technology networks failures is being extensively
deployed on point to point links within transport networks in EGYPT.
However, WDM promises advantages for switching and routing as well as for
transmission. Optical cross connects are currently being developed which can
switch an entire wavelength from an input fiber to an output fiber so that large
bandwidth circuits can be routed through the network according to
wavelength. High speed, fixed bandwidth, end to end connections called
lightpaths can then be established between different nodes. Our suggested
Trans-Egypt Network (TEGYNET) which uses optical cross connects to route
lightpaths through the network is referred to as wavelength routed network.
The average setup time, average link utilization, traffic load, blocking
probability, and achievable link utilization in the presence of both single path
and multi math routing are the major interesting parameters in the design of
TEGYNET topology. Fault cases are also dealt with during this work. Fault
examples were suggested to the network and network performance was
examined with and without the suggested solutions in terms of the parameters
mentioned previously.
Another part of the global network is dealt with during this thesis. The
submarine data link which connects Egypt transport networks from the east
and west. A study of the change in Shannon’s bit rate for the submarine data
link due to the change of signal bandwidth and optical signal to noise ratio
and the parameters which are affecting both of them is being organized along
with this work. Optical signal to noise ratio is studied as a function of signal
bandwidth which is varying with the variation of some of the environmental
factors surrounding the submarine data link when laid to sea bed. Those
surroundings such as temperature and pressure can be related and discussed
through ocean depth as relations are nearly linear. Based on experimental
data, both the deep ocean water temperature and pressure are tailored as
functions of the water depth. This study is made with respect to four multiplexing techniques, coarse wavelength division multiplexing (CWDM),
wavelength division multiplexing (WDM), dense wavelength division
multiplexing (DWDM), and ultra wide wavelength division multiplexing
(UW-WDM). Every technique of the previously mentioned was defined in
terms of its effect on channel spacing and repeater spacing as the two are
considered important network resources.