Opensky Radio System | Open sky radio | Harris Radio basics

This tutorial covers basics of Opensky Radio System. It mentions features of open sky radio developed by Harris corp. It mentions working of Opensky Radio System.

What is Opensky radio system:
It is digital radio technology supporting both voice and data transmission on the same frequency channel using TDMA access technique. Both voice and data are carried in different time slots. It uses voice over IP technology. Opensky radio system operates in 700 MHz or 800 MHz or 900 MHz bands.

This wireless radio communication system is developed by the M/A Com Inc. which has been acquired by the Tyco electronics. Later Tyco electronics wireless system division (formerly known as M/A COM) is later acquired by Harris Corporation.

Features of Open Sky Radio

Following table mentions features of open sky radio.


Specifications Opensky radio system
Radio Technology Type Digital
Access Technique TDMA (Time Division Multiple Access)
Frequency of operation 700/800/900 MHz AMPS Band
Frequency Channel Bandwidth 25KHz
Number of time slots per channel 4
Aggregate Data rate 19.2 Kbps

Working of Opensky radio system

Opensky Radio System

Let us understand working of the opensky radio system as shown in the figure-1. As shown dedicated downlink band (869 MHz to 894 MHz) and uplink band (824 MHz to 849 MHz) are used similar to AMPS System. Refer AMPS System for more information.
• In Opensky radio system, 25 Watt repeaters are installed on the cell sites.
• All the Opensky handset or phone uses single frequency and any time slot out of four per channel for communicating with the repeater to establish the voice or data call with the other opensky handset.
• Each opensky handset uses unique IP address to have data communication in the network. Moreover it uses SLIP/PPP protocols for establishing connection needed for data applications.
• Encryption is being used for data payload in order to provide secured communication.
• Both voice call and data call runs simultaneously over the radio. When the voice call is received on the opensky handset when the data call is in progress, the voice call will be answered without interrupting the ongoing data call.

Other Digital Radio and Analog Radio Systems

TETRA Radio System
Difference between TETRA and TETRA2 system
APCO-25 versus APCO-16
Opensky Radio System
DMR-Digital Mobile Radio
iDEN-Integrate Digital Enhanced Network

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