Prerequisites: What is TDMA?
Instead of using the single antenna beam, there is a huge number of narrow antenna beams that can be used by switching the interconnection of the antenna in synchronism with the TDMA frame rate, hence covering the zone sequentially. This helps in maintaining continuous communication on the entire coverage area. This whole thing is called Satellite Switched TDMA (SS/TDMA).
The uplinks signals which are further received by satellite are then demodulated to recover the streams of bit. These are structured in form of a sequence of packets, addressed to the different receiving earth stations. The satellite creates a TDMA frame of data which contains addresses to the specific earth stations and switches. It transmits the beam in the direction of receiving earth stations in the form of packets that are been transmitted.
Features
- Satellite Switched TDMA provides an additional level of access as it consists of rapid reconfiguration of antenna beams.
- Interconnection between uplink and downlink transmission is been performed by a high-speed matrix.
- Satellite Switched TDMA provides full interconnection for various coverage of regions.
- In the terms of beam width Satellite Switched TDMA provides better coverage of the region.
- For maintaining continuous communication on the entire coverage region Satellite Switched TDMA provides a baseband processing transponder.
Advantages
- As TDMA is digital it has all the advantages over the FDMA.
- It has Resistance to noise and interference.
- According to changing traffic demands, this system can be easily reconfigured.
- Can easily handle mixed voice, traffic data, and video.
- Intermodulation distortion/noise is been reduced.
Disadvantages
- Precisely synchronization is been required.
- If we are using all the transponder bandwidth, then we require a high bit rate of transmission on each and every earth station. Which means it requires high transmission power than the FDMA.
- Because of the high transmitting bit rate, it is not suited for narrow-band signals which come from the small earth stations.