Published on Feb 12, 2016
iDEN is a mobile telecommunications technology, developed by Motorola, which provides its users the benefits of a trunked radio and a cellular telephone. iDEN places more users in a given spectral space, compared to analog cellular and two-way radio systems, by using speech compression and time division multiple access TDMA. Notably, iDEN is designed, and licensed, to operate on individual frequencies that may not be contiguous. iDEN operates on 25kHz channels, but only occupies 20 kHz in order to provide interference protection via guard bands. By comparison, TDMA Cellular (IS-54 and IS-136) is licensed in blocks of 30 kHz channels, but each emission occupies 40 kHz,and is capable of serving the same number of subscribers per channel as iDEN.
Description of iDEN
More Than a Wireless Phone
iDEN technology offers you more than just a wireless phone. It's a Motorola complete communications system that you hold in your hand. Combining speakerphone, voice command, phone book, voice mail, digital two-way radio, mobile Internet and e-mail, wireless modems, voice activation, and voice recordings so that you can virtually recreate your office on the road.
Mobile Assisted Handovers
When operating in a moving vehicle, an iDEN mobile radio can assist the fixed end system in determining when a handover to another cell should be executed. Whenever the mobile radio is not actually transmitting or receiving a signal from the fixed end system, it monitors outbound signals from neighboring cells and measures the received power and signal quality of these signals. When it determines that the signal from a neighboring cell is of higher quality than the signal from the fixed end system in its currently assigned cell, it transmits a handover request to the fixed end system. The iDEN infrastructure can also query a mobile radio for a measurement report. The mobile radio then transmits data back to the fixed end system indicating the received signal strength detected and measured by the mobile radio.
IP Multimedia Subsystem (IMS)
The IP Multimedia Subsystem (IMS) is a standardised Next Generation Networking (NGN) architecture for telecom operators that want to provide mobile and fixed multimedia services. It uses a Voice-over-IP (VoIP) implementation based on a 3GPP standardised implementation of SIP, and runs over the standard Internet Protocol (IP). Existing phone systems (both packet-switched and circuit-switched) are supported.
How Does iDEN Work in PTT
iDEN enables communications to begin with the press of a PTT button on the handset, rather than through completion of a standard cellular call. A call is formed by combining separate point-to-point connections between each IP endpoint at a managing entity known as the iDEN Applications Server, deployed on the provider’s IP-based Wide Area Network (WAN).