How do ALE stations establish contact?

Automatic Link Establishment (ALE) is a robust communication system standard used primarily on HF bands to automate the process of finding a usable frequency. Because HF propagation changes constantly, manual frequency hunting can be tedious and unreliable. An ALE-equipped radio operates by constantly scanning a pre-programmed list of frequencies. While scanning, it listens for its specific digital address or call sign. When another station initiates a call to that address, the receiving radio stops scanning, links up on that specific frequency, and alerts the operator. ALE is entirely an RF-based technology and does not rely on the internet for paging. It also uses digital burst handshakes rather than constant tone codes or backscatter echoes to establish the link.