What is Multiple Access?
Managing the digital traffic of our wireless world.
Think of Multiple Access as the traffic controller for radio waves. It is the protocol that prevents millions of signals from crashing into each other on a shared communication channel.
By organizing data from multiple transmitters into one structured data link, it prevents crosstalk and ensures your message arrives clear and uncorrupted.
Comparison: Multiple Access Technologies
How different generations of mobile networks handle multiple users.
FDMA
Users are separated by Frequency. Each user gets a dedicated frequency band, like lanes on a highway.
TDMA
Users are separated by Time. Everyone uses the same channel, but in short, synchronized bursts or slots.
CDMA
Users are separated by Code. Unique digital identifiers allow multiple signals to overlap safely on the same frequency.
FDMA
Dedicated frequency channels for every user.
FAMA
Fixed Assignment: Channels are permanently assigned to specific users.
DAMA
Demand Assignment: Channels are assigned dynamically based on current user needs.
TDMA (GSM Frame)
8 users sharing one frequency through 577μs time slots.
In this model, users only transmit when their specific Time Slot is active. To prevent interference, TDMA requires precise Synchronization between the mobile device and the base station.
CDMA
Multiple users sharing the same band through unique spreading codes.
In this Spread Spectrum environment, all users occupy the entire bandwidth simultaneously. Because each user is assigned a Unique Code, the receiver can mathematically filter out the unwanted signals and extract only the intended data.