Tuesday, April 29, 2008

WiMax Roadmap

802.16 (Dec-2001)
Original fixed wireless broadband air Interface for 10–66 GHz, Line-of-sight only, Point-to-Multi-Point applications.

802.16a (Jan-2003)
Extension for 2-11 GHz: Targeted for non-line-of-sight, Point-to-Multi-Point applications like "last mile" broadband access.

802.16d (Oct-2004)
Adds WiMAX System Profiles and Errata for 2-11 GHz. It is never existed as standaed and also known as 802.16-2004.

802.16e (Dec-2005)
MAC/PHY Enhancements to support subscribers moving at vehicular speeds.

802.16m (not yet standardized)
Path towards 4G. To provide datarate of 100Mbps for mobile and 1Gbps for fixed applications, includes Frequency overlay, Adhoc Frame Relay techniques to increase the system capacity and internet speed.

Data rates of 100 Mbit/s for mobile applications and 1 Gbit/s for fixed applications, cellular, macro and micro cell coverage, with currently no restrictions on the RF bandwidth (which is expected to be 20 MHz or higher). The proposed work plan would allow completion of the standard by Sept 2008 for approval by Dec 2008.
- provides better mobility
- low latency (during sleep mode to normal mode, handover etc..)
- channel bandwidth of 20 MHz, so better throughput and performence

Monday, April 28, 2008

WiMax Introduction

WiMAX, the Worldwide Interoperability for Microwave Access, is a telecommunications technology aimed at providing high speed wireless data over long distances in a variety of ways, from point-to-point links to full mobile cellular type access. It is an assortment of technical specifications called 802.16.

WiBro (Wireless Broadband) is a wireless broadband Internet technology being developed by the South Korean telecoms industry. WiBro is the South Korean service name for IEEE 802.16e (mobile WiMAX) international standard. WiBro adapts TDD for duplexing, OFDMA for multiple access and 8.75 MHz as a channel bandwidth. In February 2002, the Korean government allocated 100 MHz of electromagnetic spectrum in the 2.3 - 2.4 GHz band.

Saturday, April 26, 2008

The journey of communication: From 1G to 4G

Communication systems have evolved since the time the first voice communication device that is the telephone was invented by Graham Bell. Experts have classified the communication technique technologies on basis of time frame as first generation, second generation or 2G, Third generation or 3G and the fourth generation or 4G.

Each of these technologies while being grouped into first , second, third or fourth generation technology is to meet the standardisation norms as floated by International Telecom Union (ITU) – a United Nations body for policy formulation on telecommunication sector.

First generation: Almost all of the systems from this generation were analog systems where voice was considered to be the main traffic. There was no or very little security as the data was transferred and the voice could be heard by third person. AMPS is an example of 1G system.


Second generation: Here commercialization of communication system started and the analog systems evolved to become digital systems. The data was transferred in discrete form and hence could be coded or technically aliased, thereby enhancing the security. GSM, GPRS, IS95 are some of the example of 2G systems.


Third generation: To meet the growing demands in network capacity, rates required for high speed data transfer, multimedia applications and increased security over data transfer 3G standards started evolving. They are based on two parallel backbone infrastructures, one consisting of circuit switched nodes, and one of packet oriented nodes. EDGE, UMTS, CDMA falls under 3G technologies.


Fourth generation: Though no formal standards for 4G have been established by ITU as yet but experts in telecommunication field have begun to design the technologies as 4G technology. The infrastructure for 4G will be only packet-based (all-IP). These are some of the technologies which are being considered as pre-4G: WiMax, WiBro, iBurst and 3GPP Long Term Evolution.

Thursday, April 24, 2008

Welcome !!

Hello Everybody,

Wolcome to WiMax and Wibro blogspot. Share your views and ideas on WiMax and WiBro standard here.

References:
1. Fundamental of WiMAX by Jeffrey G. Andrews, Arunabha Ghosh and Rias Muhamed

Thank you