Access Method Technology

Access Method

Technology plural access is method used to some information canals transmission at frequency band which have been determined. In general there are three kinds of accessing plural that is FDMA, TDMA, and CDMA.

FDMA (Frequency Division Multiple Access) Technique FDMA is technique access plural which generally used by cellular communication. Where delivered information signals through transmission media which is same to be differentiated frequency to signal every, that way between information one with other information can transmitted and accepted differentiated of frequency.











Spectrum RF for the technique of FDMA

TDMA (Time Division Multiple Access) Technique TDMA is technique access plural where information occupying of same frequency channel and differentiated of transmission time. Become this technique will use difference of time between one information with other information in same frequency channel. Superior technique TDMA is bandwidth frequency compared to smaller used system of FDMA, but practically this technique still has limitation because speed of time used sampling will generate separate bandwidth.

Spectrum RF for the technique of TDMA

CDMA (Code Division Multiple Access) Technique CDMA is technique using code to differentiate between information which is one with other at same transmission channel, this technique not affect by transmission time and frequency, or this technique can some information transmitting with same frequency and during which at same time. So that limitation transmission media limited by bandwidth not make problems by using this technique.










Spectrum RF for the technique of CDMA

Basic concept of CDMA (Code Division Multiple Access) is communications system which use concept of cellular where cell is constrain for allocation used frequency and cell used constrain to determine customer constrain to service don’t customer which don’t service. Even problems the services amount or channels can overcome with system of multiplex just remain to there constrain use technique of multiplex, so that solution or constrain cell focus will not become effective again. Single way able to overcome this problem is improved performance of system multiplex. Temporarily this system of multiplex felt have some excesses by improving service capacities needn't again minimize physical of cell. Code Division Multiple Access (CDMA) is method access with user which a lot occupy one same cell areas and use same channel transfer of information (Communications). Usage of same channel have the meaning of every user same frequency and same during to communicated. Because using same frequency and during which at the same time between user, hence to differentiate user which is one with system the other CDMA use technique spread spectrum. Spectrum Spread is transmission technique by using code the method of spreading. That Code spreading is used as identification or can be conceived by address for every user which it uses same frequency and spanning same time also with the other user, so that receiver user will ear. Access plural is method used to some discussion channels frequency bands which have been determined.