VSAT Networks (TDM / TDMA)

Asia Broadcast Satellite (ABS) provides cost effective and customized VSAT solutions to meet the needs of SMEs, MNCs, government organizations, as well as other network and communication service providers. Using the wide coverage and high power of the ABS-1 satellite, as well as expert technical staff, industry leading hardware providers and teleport operators, ABS can meet the most unique requirement.

ABS with its available Hub can provide TDM/TDMA VSAT network services with a six meter antenna and a VSAT antenna (90cm to 3m depending on the location). All channels are shared and the remote terminals are online, offering exceptionally fast response times.

The Main TDM/TDMA Network Hub transmits a channel divided into time slots (TDM), that is received by all VSATs, but can also be addressed to a specific group. Each VSAT contends for time slots on a shared (TDMA) inbound channel. If there is a collision in a slot, it will automatically re-transmit after a random time delay. Thus, there are two main channels on the satellite: a TDM outbound from the hub to VSATs and a TDMA inbound from VSATs to the Hub.

There are several advantages to typical TDM/TDMA platforms, ABS engineers have designed a superior network over a mesh solution with the following features:
  • Built-in application QoS to classify and prioritize any application, including Voice.
  • Double-Hop voice has been determined to be acceptable, in real deployments.
  • Built-in Real Time Traffic Management features to minimize jitter and delay across the network even in a severely congested network.
  • CIR (committed information rate) allocation to any remote site with dynamically allocated burstable bandwidth based on demand.
  • CIR allocation by application. This feature allows CIR allocation to be triggered based on a configured application, such as voice.
  • Rapid allocation and de-allocation of bandwidth based on demand. Performed 8 times per second.

VSAT TDM/TDM Technical Description:
The Main TDM/TDMA Network Hub transmits a link channel divided into time slots TDMA (Time Division Multiplexing Access). This link (Voice or Data) is received by all Remote Sites (VSAT terminals), or can also be addressed to a specific group depending on the required application. Each Remote VSAT terminal contends for time slots on a shared (TDMA) inbound channel. If there is a collision in a slot, the data is automatically re-transmitted after a random time delay. Thus, there are two main channels on the satellite: a TDM outbound from the hub to VSATs and a TDMA inbound from VSATs to the Hub.