Point-to-Point(P2P) Point to point is used where there are two points of interest: one sender and one receiver. This is also a scenario for backhaul or the transport from the data source (data center, co-lo facility, fiber POP, Central Office, etc) to the subscriber or for a point for distribution using point to multipoint architecture. … Read more
One of the most often heard descriptions of WiMAX in the press is that it is “Wi-Fi on steroids”. In truth, it is considerably more than that. Not only does WiMAX offer exponentially greater range and throughput than Wi-Fi (technically speaking 802.11b, although new variants of 802.11 offer substantial improvements over the “b” variant of … Read more
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
How Spreading & Dispreading in WCDMA-3G ? Traditional radio communication systems transmit data using the minimum bandwidth required to carry it as a narrowband signal. CDMA system mix their input data with a fast spreading sequence and transmit a wideband signal. The spreading sequence is independently regenerated at the receiver and mixed with the incoming … Read more
Frequency diversity is inherent in a spread spectrum system. A fade of the entire signal is less likely than with narrow band systems. Combats Fading, Caused by Multipath Fading Acts like Notch Filter to a Wide Spectrum Signal May Notch only Part of Signal Fading is caused by reflected images of an RF signal arriving … Read more
The control plane includes the application protocol. It also includes the signaling bearers for transporting the application protocol messages. The application protocol is used for setting up bearers in the radio network layer. For example, radio access bearers or radio links. Figure shows “Control plane protocol stack” comprises Radio Resource Control (RRC), Packet Data Convergence … Read more