iDEN network basics | Integrated Digital Enhanced Network
This tutorial covers basics of iDEN network system. It mentions features of iDEN network developed by MOTOROLA. It mentions working of iDEN (Integrated Digital Enhanced Network) system.
What is iDEN:
The term iDEN refers to Integrated Digital Enhanced Network. The technology has been developed by Motorola which incorporates benefits of both trunked radio and cellular telephone.
iDEN uses GSM signalling in order to provide call establishment and MM (Mobility Management). The existing GSM protocol stack has been modified in iDEN with additional specifications/features. The service provides Sprint/Nextel has launched iDEN networks across the globe in selected coutries to provide services to the customers.
The iDEN technology offers following benefits:
• Provides two-way digital radio service.
• Supports features of a typical digital wireless phone.
• Provides SMS services.
• Provides data services using existing IP network.
Features of iDEN
Following table mentions features of iDEN.
|Radio Technology Type||Digital|
|Access Technique||FDMA (Frequency Division Multiple Access), TDMA (Time Division Multiple Access)|
|Frequency of operation||800 MHz Band, 806-821 MHz for Transmit and 8510866 MHz for Receive|
|Number of time slots per channel||6|
|Number of Users||Total 30 frequencies and 6 users per frequency are supported|
|Data rate||96 Kbps|
|Mode of communication||Direct Connect or Push to Talk (PTT)|
Working of iDEN network system
• Let us understand working of the iDEN network system as shown in the figure-1.
• There are two major components in an iDEN network viz. Base Transceiver System (BTS) and iDEN phones. BTS is interfaced with GSM subsystems such as MSC (Mobile Switching center) and GMSC (Gateway MSC) to have connectivity with GSM infrastructure systems. • As shown dedicated downlink band (851 to 866 MHz) and uplink band (806 to 821 MHz) are used.
• The band is divided using FDMA with 25 KHz of channel spacing. There are 6 slots in each of the channels using TDMA to accommodate more number of users. Further speech compression is enabled to increase capacity of users supported by iDEN network.
• iDEN handset houses SIM card similar to GSM mobile phone. As the user switches on the phone, he/she finds the iDEN users on the display panel available at that time on the network.
• He/she can connect directly using PTT and start communicating without any need of calling or ringing the recipient's iDEN phone. The operation is similar to Walkie-Talkie.
• iDEN network supports about 30 frequencies in which about 6 users can interact on each of the frequencies.
Typically iDEN phones support features such as GPS, WAP etc. It also supports features of normal GSM mobile phone.
Digital Access Cross connect switch can be used to connect T1/E1 lines with iDEN equipments. Gateway can be used to provide connectivity with PSTN, ISDN and PDN (Packet Data Network).