Mobile WiMAX allows any telecommunications to go mobile. Mobile WiMAX takes the fixed wireless application a step furher and enables cell phone-like applications on a much larger scale. For example, mobile WiMAX enables streaming video to be broadcast from a speeding police or other emergency vehicle at over 70 MPH. It potentially replaces cell phones … Read more
In 1998, the Institute of Electrical and Electronics Engineers (IEEE) formed a group called 802.16 to develop a standard for what was called a wireless metropolitan area network, or wireless MAN. Originally, this group focused on developing solutions in the 10GHz to 66GHz band, with the primary application being delivering high-speed connections to businesses that … Read more
Second-generation broadband wireless systems were able to overcome the LOS issue and to provide more capacity. This was done through the use of a cellular architecture and implementation of advanced-signal processing techniques to improve the link and system performance under multipath conditions. Several start-up companies developed advanced proprietary solutions that provided significant performance gains over … Read more
As DSL and cable modems began to be deployed, wireless systems had to evolve to support much higher speeds to be competitive. Systems began to be developed for higher frequencies, such as the 2.5GHz and 3.5GHz bands. Very high speed systems, called local multipoint distribution systems (LMDS), supporting up to several hundreds of megabits per … Read more
The history of broadband wireless as it relates to WiMAX can be traced back to the desire to find a competitive alternative to traditional wireline-access technologies. Spurred by the deregulation of the telecom industry and the rapid growth of the Internet, several competitive carriers were motivated to find a wireless solution to bypass incumbent service … Read more
Here I write about what is main work of Acquisition Indicator Channel AICH in 3G There is 2 types main work of AICH Carrying the Acquisition Indicators (AI), SF = 256 There are 16 kinds of Signature to generate AI The Acquisition Indicator Channel (AICH) is a common downlink channel used to control the uplink … Read more
CDMA extends the idea of diversity reception with the concept of soft handoff. In the slide, a mobile CDMA phone has established a call with base station one. As the mobile moves away from base station one and approaches base station two, a device in the phone known as the searcher identifies base station one … Read more
SRNC and DRNC are concepts for a connected UE. The SRNC handles the connection to one UE, and may borrow radio resources of a certain cell from the DRNC. Drift RNCs support the Serving RNC by providing radio resources A UE in connection state has at least one and only one SRNC, but can has … Read more
Here I write about PRACH Message Structure and PRACH Access Timeslot Structure for WCDMA 3G with its Flow in Image. The data and control bits of the message part are processed in parallel. The SF of the data part can be 32, 64, 128 or 256 while the SF of the control part is always … Read more
Main work of Primary Common Control Physical Channel PCCPCH in 3G wcdma as below. Carrying BCH transport channel Fixed rate, fixed OVSF code (30kbps，Cch, 256, 1) The PCCPCH is not transmitted during the first 256 chips of each time slot The Primary Common Control Physical Channel (P-CCPCH) is a fixed rate (SF=256) downlink physical channel … Read more