Industry Standards, Spectrum and Regulation

24. What is IMT-2000 and define its current relationship with WiMAX technologies?
In 1999 the International Telecommunications Union – Radio communications (ITU-R) defined a set of standards called IMT-2000, commonly known as 3G technologies. The IMT-2000 provides a framework for worldwide wireless access by linking the diverse systems of terrestrial and satellite based networks.

The IEEE submitted a formal proposal to the ITU-R to make a subset of the 802.16 (WiMAX) standard a member of the IMT-2000 family, as defined by ITU-R recommendations. The WiMAX Forum provided substantial supporting material in order to make WiMAX a member of the IMT-2000 family. The WiMAX Forum was instrumental in the development of the supporting material necessary to include WiMAX in the IMT-2000 family.

25. What frequencies does WiMAX technology operate on?
The WiMAX Forum currently supports continued rapid WiMAX user adoption in the 2.3 GHz, 2.5 GHz, and 3.5 GHz frequency bands, with additional spectrum bands to come. The WiMAX Forum is working with operators and equipment manufacturers to expand the frequency allocation to cover all the key spectrum bands that our member companies identify as interesting to potential WiMAX service providers such as 700 MHz. For mobile applications, initial profiles have been developed for 2.3, 2.5, and 3.5 GHz. These are to address the current market demands by operators.

The WiMAX Forum has the ability to respond rapidly to development of additional profiles as additional spectrum is auctioned or markets change.

26. What is the status of WiMAX spectrum availability?
The WiMAX Forum continues to see progress in the assignment of spectrum tWiMAX deployments. Underused spectrum is being refarmed by regulatory authorities and new assignments are being issued. For the initial WiMAX Forum Certified™ products the majority of assignments are in the 3.4 – 3.6 GHz spectrum range. We also see market demand for license-exempt spectrum in the 5 GHz region. For mobile applications, we see many regulators making mobile spectrum allocations and assignments available in the 2.3 – 2.4  GHz and 2.5 – 2.6 GHz regions, as well as the 3.4 – 3.6  GHz band. There is now increasing market demand and regulatory activity relating to frequencies around 700/800MHz. The WiMAX Forum continues to track regional and country-specific policies and promote the availability of technology-neutral spectrum.

Members of the WiMAX Forum have access ta database to help identify available spectrum. The WiMAX Forum has formed an agreement with AT4 Wireless to provide the WiMAX Forum Spectrum and Regulatory Database, allowing member companies access to regularly updated data regarding worldwide spectrum licensing and regulatory information. The database focuses on all the key frequency bands for WiMAX Forum Certified equipment™, including 2.3, 2.6, 3.5, 3.7 and 5.8 GHz. Various user services including Reports, Maps, e-mail alerts and a newsletter are available on an opt-in basis.

27. Where can I find out more about spectrum adoptions worldwide
The WiMAX Forum Spectrum and Regulatory Database provide full technical, licensing, and regulatory information by country. Access to the full database is included with Principal membership in the Forum and is available to regular member companies by subscription. In 2008 additional features were added to the WiMAX Forum Spectrum and Regulatory Database to further enhance the tool. The updates provide WiMAX Forum member companies worldwide spectrum licensing and regulatory requirements as well as some additional new features to be implemented by AT4 wireless. These include the following:

• There is now a personal user profile feature, which allows WiMAX Forum members to subscribe and unsubscribe to services that enable them to receive specific messages and/or newsletters via email.
• Subscribers receive a notification via e-mail stating whenever there has been an update in the country.
• Subscribers receive a monthly newsletter informing about the latest news concerning WiMAX technology in the worldwide market (public consultants, licensing auctions, new regulation, etc).
• Additional information on regional organizations is also be included in the database.

A trial version of the WiMAX Forum Spectrum and Regulatory database is available at www.wimaxforum.org/members/spectrum_database.

28. What is the WiMAX Forum doing tallow for roaming among compatible networks?
The WiMAX Forum has a Global Roaming Program that allows operators and vendors to easily obtain the information required to establish WiMAX roaming services. The program is live and can be accessed through a link on the WiMAX Forum public web site at www.wimaxroaming.org.

Roaming capabilities are vital for mobility as roaming allows subscribers to access WiMAX and other services while traveling outside their home network geographical coverage area. The WIMAX Forum Global Roaming program includes several documents for WiMAX Forum member companies implementing roaming services, including technical specifications, a test plan, a roaming contract template and a guide to follow when implementing roaming.

29. What are the next steps with IEEE?
IEEE 802.16m air interface is the next major landmark in the WiMAX standard’s evolution beyond IEEE 802.16e-2005. WiMAX Forum will adopt IEEE 802.16m once the standard is completed, which is expected to occur in the first half of 2010. The IEEE 802.16 Working Group has defined its expected parameters for IEEE 802.16m and all products based upon IEEE 802.16e-2005 will be forward compatible to the future 802.16m IEEE standard.

In addition to its work with the IEEE, WiMAX Forum is committed to contributing to the longer-term work of the International Telecommunications Union, both with enhancements tIMT-2000 and IMT-Advanced. As such, we will be submitting IEEE 802.16m in conjunction with the future WiMAX Forum Mobile System Profiles (including both TDD and FDD schemes) for inclusion in IMT-Advanced.

30. What is orthogonal frequency division multiplexing (OFDM)?
OFDM is a digital encoding and modulation technology. It has been used successfully in wireline access applications, such as Digital Subscriber Line (DSL) modems and cable modems as well as WiFi. Products from WiMAX Forum member companies are using OFDM-based 802.16 systems to overcome the challenges of NLoS propagation. OFDM achieves high data rate and efficiency by using multiple overlapping carrier signals instead of just one. All future technologies for 4G will be based upon OFDM technology.

Orthogonal Frequency Division Multiple Access (OFDMA) is enhanced OFDM and used in Mobile WiMAX technology and the IEEE 802.16e-2005 standard, and it is the foundation for the next-generations of mobile broadband to come. It is a multi-user version of Orthogonal Frequency-Division Multiplexing (OFDM). The difference between the two technologies is that OFDMA assigns subsets of sub-carriers to individual users allowing simultaneous low data rate transmission from several users.