We are experiencing tremendous growth in mobile technology and seeing tremendous innovations in how the mobile experience is changing the usage pattern of individuals.However I am personally interested in sharing some facts about the underlying technology.Here’s some questions that I was initially curious about and found some interesting answers and would like to share it with you.
1.) Why we only use WDMA technology in Optical fibers? Why not FDMA or TDMA or CDMA or other technology?
Ans.) Before discussing the question let us know something about WDMA. WDMA or Wavelength Division multiple access is the technique in which we divide a signal into different wavelengths and send it via communication line or transmission line. WDMA is widely used in OPTICAL Fiber.
But why?
Reason behind this is very simple. As we all know that optical fiber uses Ray of Light for the communication or transmission. Now, Ray of light always can be divided in to wavelengths only. Through this technique, it enable multiple wavelengths (colors of light) to be paralleled into the same optical fiber or through free space with each wavelength potentially assigned its own data diagnostics.
2.) Why we get sometimes NETWORK BUSY status in GSM mobile, but not in CDMA mobile?
Ans.) This is due to the division technology both use. In GSM we use FDMA/TDMA whereas in CDMA we use Code Division. Now in GSM, the signal is generally divided into either Frequency or time slots. So if two signals are coming at a same frequency then one of a signal will be entertained and other will get Network Busy status. For example, if 20Mhz frequency slots are allowed and it is divided into 1Mhz each. Now 20 user of 1 MHz frequency can share one slot at a time but if an 21st user enters, it will not get a free slot hence will get Network Busy status. But in code division or CDMA technique, each slot in divided into different code. So if even in above example, 21st user enters, it can share a frequency slot with different code. But it will decrease the sound quality. That’s why in some festive time or at new year night, we GSM user get network busy and CDMA voice get distorted. J
This are just few of the questions and I am sure others have interesting facts to share too.
