Aircraft Communications Addressing and Reporting System - Datalink Service Provider

Datalink Service Provider

The role of the datalink service provider (DSP) is to deliver a message from the aircraft to the ground end system, and vice versa.

Because the ACARS network is modeled after the point-to-point telex network, all messages come to a central processing location. The DSP routes the message to the appropriate end system using its network of land lines and ground stations. Before the days of computers, messages would come in to the central processing location and be punched to paper tape. The tape would be physically carried to the machine connected to the intended destination. Today the routing function is done by computer, but the model remains the same.

There are currently two primary service providers of ground networks in the world (ARINC and SITA), although specific countries have implemented their own network, with the help of either ARINC or SITA. ARINC operates a worldwide network and has also assisted the CAAC in China, as well as Thailand and South America with the installation of VHF networks. SITA has operated the network in Europe, Middle East, South America and Asia for many years. They have also recently started a network in the US to compete with ARINC.

Until recently, each area of the world was supported by a single service provider. This is changing, and both ARINC and SITA are competing and installing networks that cover the same regions.