i-DEN
Integrated Digital Enhanced Network, commonly referred to as iDEN, is a mobile communications technology, developed by Motorola, which provides its users the benefits of a trunked radio and a cellular telephone. Sprint Nextel is the largest US retailer of iDEN services. iDEN places more users in a given spectral space, compared to analog cellular systems, by using time division multiple access (TDMA). Up to six communication channels share a 25 kHz space; some competing technologies place only one channel in 12.5 kHz. iDEN is available in other countries through several carriers including Nextel International. Nextel International allows direct connect (PTT operation) between users in several countries including the United States, Argentina,Brazil, Chile, Mexico, Peru, and Canada. Countries which have operating iDEN networks not currently connected with the US include Jordan, Israel, the Philippines, Singapore, South Korea, Saudi Arabia, Japan, El Salvador and China (in selected areas). Both data (such as paging, text messaging and picture messaging) and voice communications are supported by iDEN. iDEN currently is at software release 13.0, supporting 3200 sites maximum per urban. Software release 13.4 has recently passed its test phase and is currently being rolled out nationally to the Sprint Nextel network. Software release 14.0 is currently in its test phase with Sprint Nextel and will introduce iDEN's next generation Dispatch Application Processor (DAP). In order to provide high data rates for packet data, Nextel started to develop a 2.5G technology called WiDEN. WiDEN is a planned expansion on the iDEN system, where instead of using a normal 25 kHz channel for packet data, it will encompass 4 carriers (100 kHz) into one channel. This would have allowed download speeds of 96 kbit/s, which is comparable to the average CDMA2000 1x speeds from American competitors Sprint and Verizon Wireless. iDEN is a technology with no clear path for high speed wireless data. It is thought that as part of the Sprint Nextel merger, 1xEV-DO will become the infrastructure for 3G data to both Sprint and Nextel customers, as part of the transition to CDMA2000. Following Nextel's merger with Sprint, iDEN may be phased out, however Nextel has stated they will support iDEN until at least 2010. There is a smaller subset of the iDEN network called 'Harmony', which has a maximum limit of 30 sites.
