RFUnderstanding Motorola iDEN Network Technology
Advertisement
The term iDEN stands for Integrated Digital Enhanced Network.
This technology was developed by Motorola and combines the benefits of both trunked radio and cellular telephone systems. iDEN uses GSM signaling for call establishment and MM (Mobility Management). The existing GSM protocol stack has been modified in iDEN with additional specifications and features.
Sprint/Nextel launched iDEN networks globally in select countries to provide services to their customers. iDEN technology offers the following benefits:
- Provides two-way digital radio service.
- Supports the features of a typical digital wireless phone.
- Provides SMS services.
- Provides data services using an existing IP network.
Features of iDEN Network
The following table summarizes the key features of the iDEN network:
| Specifications | iDEN network |
|---|---|
| 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 851-866 MHz for Receive |
| Channel Bandwidth | 25 KHz |
| Number of time slots/channel | 6 |
| Modulation | M16-QAM |
| 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 System
Figure 1: iDEN Network Architecture
Let’s break down how the iDEN network system works, as illustrated in Figure 1.
- An iDEN network comprises two primary components: Base Transceiver Systems (BTS) and iDEN phones.
- The BTS interfaces with GSM subsystems like the MSC (Mobile Switching Center) and GMSC (Gateway MSC) to connect with GSM infrastructure systems.
- As shown, dedicated downlink (851 to 866 MHz) and uplink (806 to 821 MHz) bands are used.
- The band is divided using FDMA with 25 KHz channel spacing. TDMA provides 6 slots in each channel to accommodate more users. Furthermore, speech compression is utilized to increase the number of users supported by the iDEN network.
- The iDEN handset contains a SIM card, similar to a GSM mobile phone.
When the user switches on the phone, they’ll see the list of available iDEN users on the display. They can connect directly using PTT (Push-To-Talk) and begin communicating without needing to call or ring the recipient’s iDEN phone. This functionality is similar to a Walkie-Talkie.
The iDEN network supports approximately 30 frequencies, with about 6 users able to interact on each frequency. Typically, iDEN phones support features like GPS and WAP. They also support the standard features of a normal GSM mobile phone.
A Digital Access Cross-connect switch can connect T1/E1 lines with iDEN equipment. A gateway can be used to provide connectivity with PSTN, ISDN, and PDN (Packet Data Network).
About Motorola Inc.
Motorola is a renowned American multinational telecommunications company. They manufacture smartphones and other mobile devices running the Android OS. The company plays a significant role in developing various technologies such as mobile communications, wireless infrastructure, and consumer electronics.
