dumbi20028:

TRANSMISSION EQUIPMENT OPERATION AND MAINTENANCE

- Generic overview of transmission
- Operation and Maintenance of Access level Radios ( This could be specific to the type used in the area). However most of the guys have learnt how to operate these radios on the job without any formal basic transmission training.

I would be glad if anyone could come up with something for me on the above

pls explain and i'l be intrested too o!

There are several transmission media used in telecommunications (terrestrial and mobile telephony):

- Copper (twisted pair)
- Microwave radios
- Satellite
- Optic fibre

In layman terms, transmission engineering seeks to provide connectivity between the user(s) and the central switch (es) (where calls are routed) hence a mix of the transmission media is employed to achieve the goal. A basic scenario is illustrated below :

MSC --> optic fibre --> BSC --> Microwave ---> BTS

There are no hard and fast rules, transmission media can be used interchangeably based on the network design but note that optic fibre is the most reliable in terms of loss caused by a host of external factors but it's also very expensive to deploy hence the use of microwave radios for the access layer.

The access layer refers to the BSC - BTS or RNC - Node B interconnection.

Traditionally, transmission is based on PDH and SDH technologies which is basically TDM (time division multiplexing) but these days transmission has morphed into transport which combines PDH, SDH, Ethernet, ATM, IP,MPLS in packet switched networks. Note that these are the underlying technologies, the transmission medium remains unchanged as enumerated above.

There are several equipment vendors in the access layer space all jostling for market share like Ericsson, Nokia, Alcatel, Nera, Harris, Rad etc

The O&M engineer's job is the maintenance of these radios to ensure the availability of the transmission capacity by implementing proactive/preventive and reactive maintenance procedures as outlined by the equipment vendor.

The O&M procedures can be learnt on the job through structured knowledge/skills transfer from an operations specialist and through formal courses.

My principle is - understand the underlying technology and that will help in understanding the O&M procedures faster, I do not advocate for working blindly without any form of understanding of the basic technology

I hope I have been of some help

Hi what do u guys think of the INARTE certification? currently training for it,

There are several transmission media used in telecommunications (terrestrial and mobile telephony):

- Copper (twisted pair)
- Microwave radios
- Satellite
- Optic fibre

In layman terms, transmission engineering seeks to provide connectivity between the user(s) and the central switch (es) (where calls are routed) hence a mix of the transmission media is employed to achieve the goal. A basic scenario is illustrated below :

MSC --> optic fibre --> BSC --> Microwave ---> BTS

There are no hard and fast rules, transmission media can be used interchangeably based on the network design but note that optic fibre is the most reliable in terms of loss caused by a host of external factors but it's also very expensive to deploy hence the use of microwave radios for the access layer.

The access layer refers to the BSC - BTS or RNC - Node B interconnection.

Traditionally, transmission is based on PDH and SDH technologies which is basically TDM (time division multiplexing) but these days transmission has morphed into transport which combines PDH, SDH, Ethernet, ATM, IP,MPLS in packet switched networks. Note that these are the underlying technologies, the transmission medium remains unchanged as enumerated above.

There are several equipment vendors in the access layer space all jostling for market share like Ericsson, Nokia, Alcatel, Nera, Harris, Rad etc

The O&M engineer's job is the maintenance of these radios to ensure the availability of the transmission capacity by implementing proactive/preventive and reactive maintenance procedures as outlined by the equipment vendor.

The O&M procedures can be learnt on the job through structured knowledge/skills transfer from an operations specialist and through formal courses.

My principle is - understand the underlying technology and that will help in understanding the O&M procedures faster, I do not advocate for working blindly without any form of understanding of the basic technology

I hope I have been of some help

What happened to my last post  

Anyway, I tried to explain the Tx O&M someone requested, I'll try re-posting



There are several transmission media used in telecommunications (terrestrial and mobile telephony):

- Copper (twisted pair)
- Microwave radios
- Satellite
- Optic fibre

In layman terms, transmission engineering seeks to provide connectivity between the user(s) and the central switch (es) (where calls are routed) hence a mix of the transmission media is employed to achieve the goal. A basic scenario is illustrated below :

MSC --> optic fibre --> BSC --> Microwave ---> BTS

There are no hard and fast rules, transmission media can be used interchangeably based on the network design but note that optic fibre is the most reliable in terms of loss caused by a host of external factors but it's also very expensive to deploy hence the use of microwave radios for the access layer.

The access layer refers to the BSC - BTS or RNC - Node B interconnection.

Traditionally, transmission is based on PDH and SDH technologies which is basically TDM (time division multiplexing) but these days transmission has morphed into transport which combines PDH, SDH, Ethernet, ATM, IP,MPLS in packet switched networks. Note that these are the underlying technologies, the transmission medium remains unchanged as enumerated above.

There are several equipment vendors in the access layer space all jostling for market share like Ericsson, Nokia, Alcatel, Nera, Harris, Rad etc

The O&M engineer's job is the maintenance of these radios to ensure the availability of the transmission capacity by implementing proactive/preventive and reactive maintenance procedures as outlined by the equipment vendor.

The O&M procedures can be learnt on the job through structured knowledge/skills transfer from an operations specialist and through formal courses.

My principle is - understand the underlying technology and that will help in understanding the O&M procedures faster, I do not advocate for working blindly without any form of understanding of the basic technology

I hope I have been of some help

My bad Inglewood, sorry for butting in like i did.

Kinda new to this forum, and reading all 8 pages of the topic would have been a one hell of a job.

Anyways was just wondering if anybody is taking the INARTE exam, as well know if its industry standard for telecomms pros in naija. Thanks

Hmm

Hi,hapi new yr.i thank u all 4 using dis 2 make an impact.i apreciate u.thanks

I'm a female in 300l computer engrg in one of d uni. in d east,dis corner has enlightned me a bit cos im interest in networking nd would luv 2 major der.pls can u all help me for a place for my siwes wer i can get a good background experience in networking around May.pls prefarably in abuja.my email is nomsyks@yahoo.com.i would be glad 2 hear 4rm someone

DL:

Wow!!! finally i've gone thru the whole thread and I must say bravo to ajanlekoko, ali, inglewood and the rest of the pack 4 a job well

done, Now i'm convinced that i want to go into telecomms. I graduated last year;currently toeing the cisco track working with a systems

integration firm; almost thru with CCNP and plan to obtain a security cert. But from what i've gathered so far it seems a voice cert. make more

sense in telecoms. I definitely have to take a wireless course but I'm not sure if cisco's CCNA-wireless is as broad as CWNA

(don't think so myself because of cisco's vendor proprietary status and pls pardon my lazyness for not going thru the course synopsis b4 asking)


Lastly some of u gurus have refused to state what u actually do, how u built your careers  and probably where u work (u're

anonymous so that shuldn't be a problem), I think some of u culd serve as mentors to young and aspiring engineers (more like guidance

counselling, though some of that has been exhibited at various points on the thread).

Thanx, I'm out,

Yeah I think voice pays more and its kinda more complicated than Routing & Switching,

I think Cisco is not concentrated on wireless.

Maybe you need to go for CWNA to go deeper into wireless or you take both exams

CCNA wireless and CWNA

Hi,like i said before im a 300l computer engrg student.im taking a course in telecommunications,pls can u explain in detail about CDMA nd its advantages and also the meaning of rake receiver.

nanachi:

Hi,like i said before im a 300l computer engrg student.im taking a course in telecommunications,pls can u explain in detail about CDMA nd its advantages and also the meaning of rake receiver.

Hello, I don't know anything about CDMA, you can search google for more reviews or anybody in here knows about CDMA Technology?

@AjanleKoko
Thanks for the response. My apologies for my delayed response. I got my break into the telecomms industry quite unexpectedly in July. I work as a customer care professional at the moment. Planning to write my ITIL foundation exam in a couple of days. Some advise would be welcome.

nanachi:

Hi,like i said before im a 300l computer engrg student.im taking a course in telecommunications,pls can u explain in detail about CDMA nd its advantages and also the meaning of rake receiver.

Its difficult to explain CDMA in detail in a single post. You can read the wiki article for a brief overview http://en.wikipedia.org/wiki/CDMA

Rake receiver is a collection of receivers which are each aimed at a 'multipath' component and the output of the receivers are combined to form a superior output.
http://en.wikipedia.org/wiki/Rake_receiver

1st Off Happy new Year to everyone that, it was wonderful rubbing minds together last year, I'm looking forward to doing it with everyone on the Forum again this year.
So, looking forward,
Let Me start first of with an explanation of Access Technologies.
Except in scenarios where the communication link is dedicated between two parties, there has to be some sort of channel mechanism to manage the way users access the link. The are two I'm aware of:
Random Access mechanisms where users contend with one another to use the channel to be able to send information e.g ALOHA. What we currently have as 'Ethernet' evolved from this random contentions to CSMA - Carrier Sensing Multiple Access, where users listen, that is sensing the medium, before transmitting on it. Its like at a gathering, its rude to interrupt while others are speaking, so you wait for when no-one is talking and then speak.
Now CDMA ,  Code Division Multiple Access is one of many Multiple Access Technologies. The others are FDMA, TDMA and not so popular SDMA. (Frequency, Time and Spatial). Now there's FDM, TDM, CDM ('M' here representing Multiplexing, and there's FDMA, TDMA, CDMA ('Multiple Access'). I'll get back to this in a bit.
An illustration is back to my previous example, Lets imagine we we're all physically present at a specific geographical location. Imagine that we all just started talking, not minding if the person we were trying to rap with was listening or even present! Thats Chaos.
Now, FDM is pairing each one of us with the person you intend to communicate with and then partitioning a section of the room off for just the two of you. You can have that small space for as long as you want to talk. when you're both done you come out. But remember that the amount of space is finite so at some point the amount of space could run out.
[img]http://img266.imageshack.us/img266/3974/mediaaccesstechnologies.png[/url][/img]

In the foregoing example the amount of space available is the Frequency Spectrum which is split among the pairs.Once it runs out no more space for communication until the others are through talking. The paired up folks cannot move outside their partitioned space, well as long as they want to keep talking with their intended. After a while the room is made up of cubicles. No-one's voice level is expected to rise above what his listener can meaningfully hear. That is no shouting and disturbing others in the adjacent cubicles. The thickness of the partition is our guard frequency to keep us from interfering with others.
Next is TDM. Here we all stay in the room, no partitioning so everyone can walk around freely. But we're still paired but we have a stopwatch. Anyone that wants to talk with his 'pairee' is giving a duration to speak for while others are quiet. When your time is up you both keep quiet and its someone else's turn. Until everyone has a go speaking then we start again from the beginning, "round and round we go". Here, the exists a short period when everyone is silent at the expiration of the alloted time, while we all wait for the next two to get started. Thats our guard time to keep us from interfering with others. In essence everyone has the whole room for a short period of time. You are king for a while then you lose everything and have to wait till its your turn again! In FDM you're king over a very tiny piece of land for as long as you're 'pairee' stays there with you.

Hi,hope u all are having a nice time.thanks,faakay,biina nd salihu.im on my way back to school

Thank you elders in the trade for your selfless and noble course,may God almighty continue to increase you in knowledge and wisdom.pls can the elders recomend a good training center for aspiring Telecom guy.Pls urgent and sincere reply needed. Elder Isuata,Elder Salihu,Inglewood Baba, and grand marshall Ajanlekoko please repond.God bless you all Happy new year

Before I go ahead to delve into the question about the RAKE receiver I'd like to give you a more wholistic view. Spread Spectrum techniques of which CDMA is one. It was (much like other technologies ) developed by the US military. In Wireless Communications we have Narrow-band communication and Spread Spectrum. Narrow band - I was one of those kids that ran to put on the TV and sung the National anthem with my whole heart and then listen to the opening message on NTA 2 channel 5 (yes, all for the love of Voltron!). but there was somepart of that opening announcement that kept ringing in my head 'cos it sounded so sci-fi ", with a radiated power of 100kW". Narrow band communication has to do with transmitting on a small slice of frequency at high power. thats why we have 96.9 Cool FM and you can listen in from the fringe of Sango, Ota. They transmit at a certain frequency so once you hit 96.95 the audio gets hazy an at 97.00 you hear the crackle of static. High power - to cover a large distance and maintain a high SNR kilometers from the transmitter. You tune your receiver in and leave it there. for FM the carrier is about 200kHz wide, thats as wide as the channel width needs to be. This is the issue with NB - interference and interception. If I don't want you to listen to Cool FM I start transmitting jibberish on a frequency close to theirs.If you were trying to send top-secret information through the airwaves, I just scan the different radio bands and listen in. That wouldnt work in battle. So they invented Spread Spectrum.
With spread spectrum, our channel bandwidth is made to be a multiple of the original, so we use way more bandwidth than we need and the catch is that we turn down the power. I forgot to mention, with wireless the SNR is key. Signal to Noise Ratio, you must have way more meaningful signal than noise( like a nigerian home video: the reason I can bear listening to the soundtrack is because the total time of the movie exceeds the total time of the many songs they sing in it ;-)). The lowering the power and spreading the channel is like taking a rather tool stool, the type with fancy steps tennis umpire uses that could only sit a single slim person and hammering it into a bench that was normal height but can now sit four to five hefty guys. same material, same volume you just altered the dimensions. The reason this is done is to make the signal look like noise! Why? so the enemy couldnt detect it. There are two variants - FHSS and DSSS. Frequency Hopping Spread Spectrum and Direct Sequnce Spread Spectrum.
Please permit me to start with my weird analogies again.
FHSS (an application is the ubiquitious bluetooth). Do you remember playing 'suwe' in primary school ? for the aje's who don't know its african 'hop-scotch'. Imagine You and I stand infront of the chalked out 'suwe' markings. we have each square and its parallel marked with the same number. picture two rows and six columns and that I have 24 oranges I want to give you. I shout "four" I jump to the square marked four, you jump to four also and I toss you an orange. I shout out "one" I jump, you jump, and I toss another. On and on until you have all 24 oranges in your hands. Thats the 'Frequncy Hopping'. If its still not clear, let me try this example. Instead of transmitting all our top-secret information on 96.9 FM for all radio listeners tuned in at the time to hear here's what we do. Imagine the top-secret info is "Eko O Ni Baje O!" (& no, I haven't joined AC, yet!). I've alerted you before hand to tune into Brila 88.5FM at exactly 6.00pm, 92.3 Inspiration FM at 6.02pm, Rythm 93.7FM at 6.04pm, 97.6 Metro FM at 6.06pm and The Beat 99.9FM at 6.08pm. At 6.00pm I say "Eko", zoom off to Inspiration to say "O", at 93.7 by 6.04pm all I say is "Ni" and on and on.No-one listening to any individual station can make any sense of what was said at those different times. Its the ability to keep changing your frequency with time that is the prime. Its spread spectrum because we needed five radio stations to transmit five simple words beacause we trying to send it securely. I'll get back to this in a bit.
I hope my jist is making sense ?

Hi,

I also work in Telecom world, and I am about to live/work in Lagos. Does anyone know a good broadband ISP (for at home), and what it cost?

Hope to add more to this forum once I am moved

cheers
Hank

salihu_ali:

Before I go ahead to delve ,  to this in a bit.
I hope my jist is making sense ?

in summary, narrow band uses one resonance freq. while spread sprectrum changes its resonance freq. according to a given function of time.

All contacts to u (email, gsm etc) are not available. Hw can u b reached?

lekside44:

in summary, narrow band uses one resonance freq. while spread sprectrum changes its resonsnce freq. according to a given function of time.

resonance freq?

On the request of those that asked for a training place for the CCNA -
This is the address of the CCNA training place a colleague of mine did his training at.
CAVEAT EMPTOR : I have not been there, taken any training there & I don't know the Principal Instructor.
My recommending it here is on the basis of the value my colleague derived from the course.
30 Ajose street, Mende Maryland.
08056709375
Ask of Mr.Femi

[Deleted]

atunje:

To all my predecessors on this thread,

I have just gained admission into the university and i am studying electrical/electronics engineering, I want to know all the areas of specialization in the course and i want to know which would be advisable for me to specialize in my final year.

I also want to know more about going into academics, i mean continuing my education up to the Professorship level, What challenges will i face

Lets say after my 5yrs in the university after i have obtained my B.Sc and after NYSC , can i just go straight away into the labour market?? Or do i have to proceed to the M.Sc level for better job offer, These are the things i want to know so that i can start planning towards the future.

Please i take this serious and I will appreciate all response.

Most electrical/electronics engineering students I know usually go into the telecom industry

Start by taking CCNA training to build your career. You can do this during the holidays in the uni.

Try www.mylearningacademy.com

username: demo
password: demo

it has affordable training on Oracle 11g certification, PMP and many more for less than a recharge card.

[

color=#006600]I'm Entry level position, in search of a world class career in Etisalat. However, brilliant professsional in Marketing communications. certified from skool'f media & Communication/LBS, APCON affilaite, 2yrs prof experience, howvr, Telecomms thrives and is sure for short/long-term career progressin. happy2join y'all!


stewie_G[/color]

stewie,
Kindly give me more information on professional in marketing communication. bros, i need it as urgent as anything. thanks

I urgently need the service of two facilitators  in Micro wave transmission engineering and link planning. The training run in 3 different locations in Nigeria for 5 days in the first and second week of February. Call me if interested. 08022224631

This thread is becoming interesting but issues concerning security are not arising, which leaves me to ask the question where are the security pros in the house.

Please Nairalanders, I need a frequency selective Electromagnetic Radiation Measuring Instrument, can I get it in Nigeria.
-Very Urgent Please

Good day everyone. I am a graduate of Computer Engr from a University. I have my CCNA but I am yet to secure a job. I really love to go to India to have some Microsoft certification (Server Admin.) and Cisco's. I really need u to send d details of excellent training institutes in India(which is also relatively cheap). Also, I need d names and addresses of IT companies in Lagos where I can submit my CV for job consideration. I will appreciate any additional useful info and advice. My e-mail address is sayajseol@yahoo.com and my number is 0802 4766 934.

God Bless.

Wale

Thanks