WIMAX

THE EMERGING TECHNOLOGY IN WIRELESS COMMUNICATION [Under wireless cellular Communication]

Sahu Jagannath Anil Prakash

ABSTRACT: WiMax has helped to push the wireless communication scenario into hyperdrive.For many years cables ruled the world. Optical fibers played a dominant role for its higher bit rates and faster transmission. But the installation of cables caused a greater difficulty and thus led to wireless access. The foremost of this is Bluetooth which can cover 9-10mts. Wi-Fi followed it having coverage area of 91mts. No doubt, introduction of Wi-Fi wireless networks has proved a revolutionary solution to last mile problem.However, the standard's original limitations for data exchange rate and range, number of channels, high cost of the infrastructure have not yet made it possible for WiFi to become a total threat to cellular networks on the one hand, and hard-wire networks, on the other. But the mans continuous quest for even better technology despite the substantial advantages of present technologies led to the introduction of new, more up-to-date standards for data exchange rate i.e., WiMAX. WiMax provides broadband communication in the area of over 49 km in range with the bandwidth comparable to that for cable bands - up to 10 Mbit/s and higher. The WiMAX technology allows operating in any conditions, including in the dense urban coverage, and providing a high quality of communications and data transmission rate. It provided an alternative solution to last mile problem by implementing broadband "last mile" connections, deployment of wireless access point, arrangement of high-speed communication among company branches and solution of other similar tasks. This paper presents WiMax technology, its features, real time and coming application areas. We are very happy to place this paper before the academic fraternity. Now it will be our pleasure to receive the readers feedback. We feel such a feedback is vital to improving the knowledge of an efficient engineer, thereby achieving its purpose. Key words: Last mile, Bluetooth, WiMax, Wi-Fi. INTRODUCTION: The wireless revolution is underway, and devices based on radio technologies are expected to become a significant market in the next several years. Mobile phones, cordless phones, walkie-talkies, car door openers, and garage door openers are just a few examples of radio devices that have already achieved widespread adoption in the marketplace. Out of the past

several years, innovations in wireless radio technology such as Bluetooth,Wi-Fi (ieee-802.11b) and WiMax (ieee-802.16e) have captured our attention. Some pitfalls in has led to the advent of wimax technology. WiMax offers some advantages over WiFi, a similar wireless technology, in that it offers a greater range and is more bandwidthefficient. Ultimately, WiMax may be used to provide connectivity to entire cities, and may be incorporated into laptops to give users an added measure of mobility. WiMax requires a tower, similar to a cell phone tower, which is connected to the Internet using a standard wired high-speed connection, such as a T3 line. But as opposed to a traditional Internet Service Provider (ISP), which divides that bandwidth among customers via wire, it uses a microwave link to establish a connection. Because WiMax does not depend on cables to connect each endpoint, deploying WiMax to an entire high-rise, community or campus can be done in a matter of a couple days, saving significant amounts of manpower. WHY WIMAX? The reason for pushing into WiMax technology is because of pitfalls of earlier technologies i.e., Bluetooth and Wi-Fi.Lets see the comparisons and features of those two technologies. DISADVANTAGES OF BLUETOOTH AND Wi-Fi: From above table we can conclude that the coverage areas of Bluetooth is 10mts and Wi-Fi has 100mts.Both are having lower bit rates i.e., 800Kbps and 11Mbps.So to have more coverage area and higher bit rates we move onto WiMax technology. WHAT IS WIMAX? WiMax (worldwide Interoperability for Microwave Access) is the recently approved IEEE 802.16 wireless metropolitan area network (MAN) standard for wireless access. WiMax is the real wireless architecture by which the wireless access range can extended to 49.6Kms compared with Wi-Fi 91mts and Bluetooths 9mts. WiMax 802.16 has a single carrier modulation scheme that operates between 10GHz and 66GHz radio frequency and requires line of sight towers for the connection to work. The new ratified 802.16a

extension uses a lower frequency range of 2GHz to 11GHz, and does not require line of sight towers. It also boasts 70Mbps data transfer rate that can support thousands of users. ARCHITECTURE OF WiMax: The core components of a WiMax system are the subscriber station (SS) and the base station (BS). A BS and one or more SSs can form a cell with point to multipoint (P2MP) structure. An 802.16 based system often uses fixed antenna at the subscriber station site. The antenna is mounted on the roof. Provisions such as adaptive antenna systems and sub channel stations are also supported by this system. A BS typically uses either directional or omni directional antennas. A fixed SS typically uses directional antenna while mobile or portable SS uses an omni directional antenna. Multiple BSs can be configured to form a cellular wireless compared to what can be achieved in the P2MP mode.

network. The 802.16 standard also can be used in a point to point topology with pairs of directional antennas. This increases the effective range of the system

1. Flexible Architechure: 2. High Security: 3. Quick Deployment: 4. Multi-Level Service: 5. Interoperability: 6. Portability: 7. Mobility: 8. Cost-effective: 9. Wider Coverage: 10. Non-Line-of-Sight Operation: 11. High Capacity: WIMAX ACCESS DEVICES: WIMAX SYSTEMS: This figure shows that WiMax systems may be use to provide point to point (PMP) or point to multipoint (PMP) communication services and that WiMax systems can provide different types of communication services (voice, data and video) from a common digital switching system. This diagram also shows that WiMax system can be used to provide dedicated high-speed data communication links or it may be used to provide broadband wireless service to hundreds of users in relatively large geographic area.

5. Campus Connectivity: 6. Offshore communication: Disadvantages of WiMax:

We have designed WiMax mainly for large distance communication. The main obstacle to long distance communications are limitations on battery power and poor power efficiency.

APPLICATIONS: There are many usage scenarios that can be addressed by WiMAX. The following are some mobility usage applications of WiMAX. 1) Cellular Backhaul:

CHIP ADVANCES :

2. Banking Networks: 3. Education Networks:

( How can we overcome drawback?)The main obstacles to long distance wireless communications are limitations on battery power and poor power efficiency. Regulation keeps the power levels low and the range of Wi-Fi signals short, to avoid the overcrowding of airwaves. But advances in DSP chips mean that weak signals can be deciphered, lengthening the distance that is practical for transmission, as well as improving distance and speed potential. Battery improvement is vital to make a WiMax cell phone a practicality.Nokia is working on battery and handset chip designs towards this end. Intel is increasingly involved in next generation battery and processing power for mobile devices, including digital radios that can intelligently tune in to the most efficient network like Cellular,WiFi,Bluetooth,WiMax.

AT PRESENT: At present we are using WiMax in different areas. The following are the real time applications of WiMax technology.

1. Interactive gaming. 2. VoIP, Video conference 3. Streaming media.

4. Public Safety:

IN FUTURE: In coming years WiMax also plays a vital role in :

6) www.Palowireless.com

1. 2.

Information Technology Media content download

similar in function to the General Packet Radio Service (GPRS). Intel has now promised WiMax versions of its Centrino chipset for 2004, where as Nokia says it will have battery and other technical issues solved in time to launch a WiMax cell phone in 2005.

CONCLUSION: Within five years, we expect WiMax to be the dominant technology for wireless networking. By that time it will be fully mobile, as well as providing low-cost, fixed broadband access that will open up regions where internet access has no

far not been practical.WiMax will be the most significant technology in making wireless access ubiquitous and, as the free spectrum is opened up, in creating a major shake-up of the traditional shape of the wireless and mobile communications sector. REFERENCES: 1) Information Technology (October 2004) magazine

2) www.houstuffworks.com 3) www.intelsemiworks.com
4) IEEE magazines

5) www.Homepna.org