LTE: An Introduction

Feature Article

What is WiMAX?

Defined by the IEEE, the 802.16e standard for WiMAX (Worldwide Interoperability for Microwave Access), was developed to provide a common framework for wireless connectivity in fixed, portable, and mobile environments. Simply stated, WiMAX is a scalable wireless access technology designed to provide high throughput over long distances.

Consider the existing Internet opportunities for Internet connectivity today — broadband wireline, WiFi, and even dial-up. There are issues with each one: broadband service can be expensive, depending on the provider, and it certainly isn’t available in many rural areas; WiFi has very limited range, again limiting coverage, and dial-up is simply slow and can’t come close to meeting requirements for today’s applications.

WiMAX is designed to address all these concerns. If offers the high-speed connection of broadband (with even higher data transfer rates, for that matter); it provides wireless access, significantly reducing deployment costs associated with laying fiber and extending it to buildings; it has a range that far exceeds WiFi.

While WiMAX is often said to be enhanced WiFi, perhaps a more accurate analogy would be to say it is set to do for broadband access what cell phones did for telephony. With its range and open standards design, it will enable wireless access nearly anywhere, simply by turning on a laptop, PC, or other WiMAX enabled device. It also has the potential to bring high-speed access to areas that have, thus far, been blocked from it due to a lack of fiber.

So, how will WiMAX make this possible?

A WiMAX deployment will essentially have two hardware components — a WiMAX tower and a WiMAX receiver. The tower is not unlike a cell tower, but can provide coverage to an estimated 30-mile radius. The tower connects to the Internet using a high-bandwidth wireline connection (e.g., T3), or it provide a wireless backhaul to other WiMAX WiMAX towers with LOS (line of sight) microwave links.

The receiver can be anything from a large building-mounted antenna to a small appliance, a laptop card, or even a built-in chip, like the WiFi receivers in PCs and laptops today.

NLOS (non-line of sight) connections, similar to WiFi receivers, connect devices to the tower using the 2-11 GHz frequency range, since low wavelength signals are largely immune to physical obstructions. NLOS access will not have the range of LOS service, being limited to something in the 4-6 mile radius (akin to the coverage area of cellular service).

For LOS service, a mounted antenna points at the tower, providing a stronger, more stable connection using higher frequencies (up to 66 GHz), providing less interference and greater bandwidth. LOS service can be effectively used to provide service to routers to further distribute the signal within businesses and other multi-tenant facilities.

Ultimately, a network of connected WiMAX towers will drive the deployment of an 802.20-based Global Area Network (GAN), closely resembling cellular networks, but with far fewer tower required to provide the same coverage. This will allow true ubiquitous access across the country or region, providing bandwidth comparable to cable Internet service, at the very least.

comments powered by Disqus

FOLLOW MobilityTechzone

Subscribe to MobilityTechzone eNews

MobilityTechzone eNews delivers the latest news impacting technology in the Wireless industry each week. Sign up to receive FREE breaking news today!
FREE eNewsletter