Code division multiple access, simply called as CDMA is the technology used for radio communication in the present day mobile phones. This multiple access scheme allows sending of voice, data and signals for digital radio. The channels in this technology are defined with the use of PN sequences. The major advantage with this technology is the use of same frequency channel rather than the TDMA used in GSM devices. This facility allows several mobile phones to be controlled by a few cell sites and hence, CDMA is an economical technology for mobile phones. Numerous standards have been developed for the CDMA technology. The latest standard used in mobile phones is the CDMA2000, which is compatible with the earlier standards. The CDMA standard is a proprietary standard developed by the Qualcomm telecommunication company in the United States in the year 1993. This technology is used in the mobile phones of North America and several parts of Asia. The improvements made to the standard make it... more
The General Packet Radio Service or GPRS is a telecommunications technology that is presently transforming the present shape of mobile communications. GPRS is a packet oriented Mobile Data Service providing data rates from 56 up to 114 kbit/s. Users of IS-36 mobile phones and Global System for Mobile Communications (GSM) can readily avail of this service. How does a GPRS work? A GPRS connection is linked by orientation to its Access Point Name (APN). The APN then identifies the appropriate services like Wireless Application Protocol (WAP) access, Multimedia Messaging Service (MMS), Short Message Service (SMS), and for Internet communication services such as World Wide Web access and email. The charge for GPRS data transfer is per megabyte of traffic transferred as compared to data communication via traditional circuit switching that is charged per minute of connection time, whether or not the capacity is used or is in an idle state. Thus, as compared to circuit switching, GPRS is a best-effort... more
