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Topics - sumit

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Its must that, we all know at least something about the term CDMA and GSM.Though it is very common term but its very important to know the differences  between these two term.We have some friends here who knows it very well, though i want to tell here something on this because its very important in wireless technology.. ......

  The questions that arises in here is:
            1.What is the difference between CDMA & GSM?

            2.Is it possible to use GSM sim card in CDMA handsets?

            3.What is  GSM & CDMA stands for?

1.Ans:
                   These  two different means of mobile communication being presently used world wide.The basic difference lies in the Multiplexing method.


                  CDMA uses Code Division Multiple Assess as the name itself indicates, for example if you are in a hall room occupied with number of people speaking different language. You will find that the one language you are knowing will be heard by you and the otherggs will be treated like noise. In the same manner each CDMA mobile communication takes place with a "code" communicating between them and the other end if one is knowing that code then only it can listen to the data being transmitted i.e. the communication is in the coded form.
                 

      In CDMA we allocate a unique code for every user saparately and allocate bandwidth to user.


                       On the other hand GSM is stands for global system for mobile communication. it use TDMA  & FDMA techniques as access mechanism . in GSM  we devide bandwidth in to time slots for better utilization of bandwidth.GSM uses narrowband TDMA, which allows eight simultaneous calls on the same radio frequency.
                         

                            In GSM only 30 or 35 peoples can call at at time in a single carrier but In CDMA
 apprx 70  peoples can call in a single carrier at a time.

                            CDMA  has been traditionally faster than GSM, though both technologies continue
to rapidly leapfrog along this path.

                            In CDMA technology adjacent channel interference is very  low compared to GSM.
In CDMA  the power consumption is very low it takes 23 to 30 dBm.But in GSM the power
consumption  is very high comparitive to CDMA the lower limit is 30 dbm.
             
                           The range of each technology is different, and they also have different rates and modulation schemes, and that is why handsets are different between the two technologies. GSM uses SIM cards (Subscriber Identity Module) whereas, CDMA based phones use the RUIM (Removable User Identity Module).So it is give you the answer of 2.






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CWNA(certified wireless network administrator) / introduction of CWNA
« on: February 06, 2009, 12:36:12 PM »
At first thank you very much to moderator sir for opening the section with a quick time.

thank you very much and salute to you.


now i want to tell  just an introduction about CWNA.Many of us may be know these things but this post is for those students who didnt know it well.so .............


       The CWNA is an entry-level qualification for IT professionals who are new to  wireless networking.
       It is designed for beginners who want to learn about  Wireless Networking as well as for those already working in the industry,
       who wants to brush up on their knowledge.


        If you want to build up your career in wireless sector then  i advice you that, to build up your career CWNA helps you a lot. And please remind that   CWNA not makes you an expert in wireless, it is only gives u the basics of wireless technology.
           If it possible buy the book
                        CWNA
  Certified Wireless Network Administrator
      Official Study Guide(2nd edition)

   
        But if u dont want to take ur career in that way but have curiosity about wireless then please take a good look in this forum.I will try my best.

thank you. more will come...............
 

3
CWNA(certified wireless network administrator) / nothing for CWNA students?
« on: February 03, 2009, 11:13:47 PM »
Daffodil International University also have a course for wireless technology named as CWNA(certified wireless network administrator).

  In this forum we have different section for different courses like microsft,redhat,ccna, but nothing for the students of CWNA.We have some students already complete the course and its still running. I am also complete cwna from our university.As we know wireless technology is not so vast in bangladesh.So it will be better for us to get all cwna students together where we share our knowledge.
so please add a new  thread  for the cwna students at 'Human Resource Development Institute" section.

thank you

4
Use of Forum / post delete or lock should not be given to all user
« on: January 29, 2009, 11:56:55 PM »
 when any of the member of this forum post a topic there is a option to delete/lock the topic.
from my point of view this option  should not given to all the users.
because if we all are going through comments in a topic,
 but the  topic maker wants to  delete the post(because of his/her mistake).
then whats happened??


so these two option should be in the hand of our moderator.
if anybody wants to delete or lock,he or she will take request to mod. and if mods are satisfies they can do it.
if i am wrong.......i am sorry for that

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Use of Forum / we want bangla section
« on: January 26, 2009, 08:06:50 PM »
Though the medium of our university is english,but its looking odd to see that in this forum there is nothing for bangla.
so we want at least a thread for bangla. where members are communicate each other with bangla.
we love our country and we lost 30lakh martyr to established Bangla as our mother tongue.

i request the moderator please take it in count.     

thank you

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