Mr. Thilak de Silva.BSc. Eng., MSc, CEng, FIE(SL), FIET(UK), CITP(UK), MBCS(UK), MIEEE (USA)
M.Sc. in IT - Year 1 Semester II - 2012
NetworksTransmission NetworksLTEMultiplexes
M.Sc. in IT - Year 1 Semester II - 2012
At the end of this session you will understand about the Networks, LTEs, Multiplexes and their management systems.
M.Sc. in IT - Year 1 Semester II - 2012
Networks can be divided in to three main types.
Access Networks.▪Wired▪Wireless
Switch Networks.
Transmission Networks. M.Sc. in IT - Year 1 Semester II -
2012
There are two main factors in Transmission networks.▪Transmission Media▪Transmission Technology.
M.Sc. in IT - Year 1 Semester II - 2012
One type of transmission media is Fiber.
Fiber should be terminated from a special equipment named LTE – Line Terminal equipment.
M.Sc. in IT - Year 1 Semester II - 2012
LTE LTEFiber
Including supervisory signals to supervise the end to end line.▪ Eg:- if a repeater is faulty it should be identified.
M.Sc. in IT - Year 1 Semester II - 2012
LTE LTE
Fiber Line
Repeater
Repeater
Suitable encoding of bit patterns. Eg:- Manchester Encoding
AMI CMI
Media Conversion (if necessary) Eg:-Electrical to Optical Conversion
M.Sc. in IT - Year 1 Semester II - 2012
M.Sc. in IT - Year 1 Semester II - 2012
All transmission networks terminates at LTE.
Need supervisory signals to monitor the link.
If one link is out of order or if a particular link is having high traffic the LTE finds an alternate link to send data.
This is the management part of the media.
M.Sc. in IT - Year 1 Semester II - 2012
Graphically represents all the LTEs and respective links between LETs.
Transmission media management can be done in a separate, central location.
This is for fiber optics.
Most of these software are pro-priority.
M.Sc. in IT - Year 1 Semester II - 2012
M.Sc. in IT - Year 1 Semester II - 2012
Telephone lines are connected to MUX.
Multiplexes are connected directly to LETs.
Logically Muxses forms a separate network but actually data are sent through the LETs.
M.Sc. in IT - Year 1 Semester II - 2012
Eg:- SDH (ITU-T standard)▪SDH includes a management system too.
Theses Multiplexes also has a separate management system, to divert the traffic in a failure of a link, to an alternate link.
M.Sc. in IT - Year 1 Semester II - 2012
From these two fiber restoration is done immediately. (LTE Restoration)
Only if the fiber is slow, SDH will do the restoration. (Multiplexes Restoration.)
But Fiber management software is expensive and not used in countries like Sri Lanka.M.Sc. in IT - Year 1 Semester II -
2012
Similar concept is used in switches.
Physical Layer, SDH layer and switches has separate management systems.
M.Sc. in IT - Year 1 Semester II - 2012
M.Sc. in IT - Year 1 Semester II - 2012