Vol. 3, Issue 1
A FIXED-WIRELESS WORLD
IEEE 802.16 Working Group Chair, Roger Marks, Offers His Perspective

There's a lot of talk about the wireless Internet. Some see an image of themselves surfing the Internet while cruising down the highway. Others say that high mobility, high capacity and high bandwidth just don't mix. Even more say there's room for both a limited-capacity mobile wireless community and a fixed wireless environment.

"I see people who really want to use the Internet as typically sitting at a table somewhere and focusing on it, not really in a car," explains Roger B. Marks, Chair of the IEEE 802.16, Working Group on Broadband Wireless Access. "Wireless local area networks based on the IEEE 802.11b standard is so cheap that even a coffee shop can basically offer it free or simply roll it into the cost of the coffee. But, how will that coffee shop get Internet access? I think that fixed wireless is going to be an important solution to this problem."

IEEE 802.16 is chartered to develop standards and recommended practices to support the development and deployment of fixed broadband wireless access systems. 802.16 is a unit of the IEEE 802 Local Area Network/Metropolitan Area Network (LAN/MAN) Standards Committee, the transnational forum for wireless networking standardization and the source of Ethernet standards. The Working Group brings together industry professionals from around the world to develop comprehensive standards for systems providing fixed broadband wireless access. "I feel I bring to the table a unique perspective, because I don't have a company and product driving me in any specific direction," commented Marks. "However, I do have my own bias and that is to unify toward industry consolidation and solicit broad industry support."

IEEE 802.16 is currently working on four standardization projects involving both licensed and unlicensed bands:

  1. 802.16.2 - available late June 2001 (tentatively)
    Recommended Practice for Coexistence of Fixed Broadband Wireless Access Systems

  2. 802.16 - available September 2001 (tentatively)
    Standard Air Interface for Fixed Broadband Wireless Access Systems [10-66 GHz]

  3. 802.16a - available March 2002 (tentatively)
    Amendment to Standard Air Interface for Fixed Broadband Wireless Access Systems-Media Access Control Modifications and Additional Physical Layer for 2-11 GHz

  4. 802.16b - available March 2002 (tentatively)
    Amendment to Standard Air Interface for Fixed Broadband Wireless Access Systems-Media Access Control Modifications and Additional Physical Layer for License-Exempt Frequencies

The IEEE 802.16.2 standard will be available first, rather than the initial IEEE 802.16 document. This is due primarily to its' less contentious nature. Specifically, 802.16.2 recommends practices for licensed band operators to avoid interference with each other. "Because spectrum boundary requirements stipulate that one operator can use band up to a certain frequency and another can use above that frequency, many potential problems can arise," explained Marks. "Basically, this document outlines an etiquette on how operators should minimize interference problems."

Much of the debate surrounding amendments 802.16a and 802.16b is aimed at physical layer approaches to handle the multipath expected in a non-line-of-sight environment. Orthogonal Frequency Division Multiplexing (OFDM), which uses multiple radio carriers, has significant support, but advanced signal processing in conjunction with a single carrier is also being proposed. "Both of these approaches are represented in our group. Quite possibly, both will get coverage within the standard," Marks commented.

The future prospects of fixed wireless technology are extremely promising and, due to the contributions of Marks and the IEEE 802.16 Working Group, a wireless world will become a reality. "A lot of ingredients are needed to make the technology and standards process come together, but the most essential ingredient, is just plain work," states Marks. "People have to sit down, think through the issues and come up with suggestions. We've been lucky enough to have the world's most creative and critical thinkers focused on the problem. That's what moves the process and makes IEEE 802.16 a driving force."

Roger Marks is a Physics graduate from Princeton University, with a Ph.D. in Applied Physics from Yale University. He completed a postdoctoral appointment at the Delft University of Technology (The Netherlands). He is the author of over 70 journal and conference publications, the recipient of the IEEE Morris E. Leeds Award, and developed and chaired the IEEE Radio and Wireless Conference (RAWCON) from 1996 through 1999. Currently, Marks serves as an IEEE Distinguished Lecturer.