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Technology Stocks : WiMAX & Qualcomm: OFDM Technologies for BWA -- Ignore unavailable to you. Want to Upgrade?

To: Eric L who wrote (43)	8/27/2005 12:23:54 PM
From: Eric L	Respond to of 86

Backwards Compatability: OFDM256FFT v. SOFDMA .... The following is excerpted from an SR telecom whitepaper ... srtelecom.com 802.16-2004 Physical (PHY) Layers The 802.16-2004 standard, published in 2004, includes options for three different Physical (PHY) layers: • Single Carrier • OFDM256 • OFDMA The WiMAX Forum has thus far supported the OFDM256 physical layer within the 802.16-2004 standard for first-generation WiMAX products. Since volume deployment of WiMAX-certified equipment is expected to be driven by nomadic and mobile applications, it is important to observe the direction of the 802.16e standard to understand the technology that will be used for these mass-market deployments. Support within the IEEE for SOFDMA grew significantly throughout 2004, with many of the mobile vendors becoming more active. Momentum continues to build in 2005. Whereas the 802.16-2004 standard addresses fixed wireless applications only, the 802.16e standard can serve the needs of fixed, nomadic, and fully mobile networks. Although 802.16e is generally perceived as the mobile version of the standard, in reality it serves the dual purpose of adding extensions for mobility and including new enhancements to the Orthogonal Frequency Division Multiplexing Access (OFDMA) physical layer. This new enhanced 802.16e physical layer is now being referred to as Scalable OFDMA (SOFDMA) and includes a number of important features for fixed, nomadic, and mobile networks. Because of these advantages, most of the industry will build their 802.16e-based products using SOFDMA technology. However, the 802.16e standard is not just for mobility. There are also many compelling reasons for using SOFDMA in fixed broadband wireless access (BWA) networks. This paper focuses on the advantages that SOFDMA provides for fixed wireless applications. In Korea, the Telecommunications Technology Association (TTA) has recently decided to align its wireless/broadband (WiBRO) high-speed Internet standard with SOFDMA as well. Intel has also announced at industry conferences that SOFDMA will be the PHY layer of choice for future fixed and portable WiMAX applications, such as indoor customer premise equipment (CPEs), notebooks, and Personal Digital Assistants (PDAs). This recent industry shift is important because SOFDMA is not backward compatible with OFDM256, which is the basis of most early "pre-WiMAX" equipment. SOFDMA Benefits The benefits of SOFDMA for fixed wireless applications, include the following: Lower Cost Driven by Volume Opportunity • Fixed wireless CPEs will be able to use the same modem chipset used in personal computers (PCs) and PDAs. • Base stations will be able to use the same chipsets being developed for low-cost WiMAX access points. • Increased volume will also justify the investment for higher-level integration of radio frequency (RF) chipsets, further driving down costs. • Peak-to-Average-Power-Reduction (PAPR) techniques incorporated within the standard will enable lower cost power amplifiers to be used for SOFDMA without compromising system gain. Non-Line-of-Sight (NLOS) Coverage • Basic capabilities of SOFDMA will offer similar coverage as OFDM256. Above these basic capabilities, there are several areas listed below where SOFDMA should outperform. • Important optional techniques for improving NLOS coverage, such as diversity, space-time coding, and Automatic Retransmission Request (ARQ), are included as a part of SOFDMA as they are for OFDM256. In some cases, the capabilities are further enhanced for SOFDMA; for example, hybrid-ARQ and additional diversity schemes. • Finer granularity of sub-channelization improves SOFDMA system gain to enable deeper indoor penetration. • Higher performance coding techniques; for example, Turbo Coding and Low-Density Parity Check (LDPC), are being implemented in first-generation SOFDMA chipsets, further improving system gain and NLOS coverage. (Optional higher-performance coding also exists with OFDM256, but is not implemented in most first-generation WiMAX chipsets.) • Downlink sub-channelization of SOFDMA enables additional flexibility for trading-off coverage versus capacity. • Volume opportunity for nomadic applications is encouraging lower-cost solutions (chipsets) to enable Adaptive Antenna Systems (AAS) and Multiple-Input-Multiple-Output (MIMO) for improved coverage. • SOFDMA sub-carrier spacing is independent of channel bandwidth. Scalability ensures that system performance is consistent across different RF channel sizes (1.25-14 MHz). • Larger Fast Fourier Transform (FFT) sizes of SOFDMA can cope with larger delay spreads making the technology more resistant to multipath fading that is characteristic of NLOS propagation, particularly with larger RF channels. << - Eric -

To: Eric L who wrote (43)	8/27/2005 1:15:17 PM
From: Eric L	Respond to of 86

DailyWireless on Backwards Compatibility to WiMAX 802.16-2004 What happened at the IEEE 802 plenary and within the 802.16 working group sessions there may shed light on backwards compatibility issues. My guess is that once 802.16e publishes there will be an 802.16-2005 "ubber-standard" incorporating 802.16e and 802.16f published. >> 16e: Backward Compatibility - NOT samc DailyWireless July 06 2005 tinyurl.com Light Reading says the upcoming edition of Unstrung Insider notes that the two WiMax specifications (802.16-2004 and 802.16e), were originally supposed to be backwards compatible. But they're not. ¹ ¹ See "A Spec Divided" in the prior post. 802.16 Task Group E (802.16e) is charged with developing an amendment to the current 80.16-2004 standard that covers 'Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands.' "This implies 802.16e would be used for both fixed and mobile access – and according to several sources, dual fixed-mobile operation is still the goal," writes the report's author, Gabriel Brown, chief analyst for the Unstrung Insider. ... Among the reports key findings: • The first Mobile WiMax services will launch in Korea in mid 2006, using Samsung equipment; U.S. service launches will follow, possibly as soon as 2007. • Stealth chipset startups are attempting to leapfrog the market and go directly to Mobile WiMax (802.16e); names in the frame include Beecem, SiWave, Cygnus, and Runcom. • Adaptix claims to have already demonstrated system-level mobility based on scaleable OFDMA (Mobile WiMax). • A market for 802.16e line cards and software will emerge alongside demand for smart antenna software suites, as major fabs and OEMs catch on to Mobile WiMax's potential. The IEEE expects to publish the 802.16e standard by the end of the year. IEEE 802.16e can use both licensed and unlicensed bands as well as simplex or duplex configurations. Along with mobility support, 802.16e adds several features to the PHY, including OFDMA (Multiple Access), a scalable FFT size (proportional to channel, up to 1000 OFDM carriers) and better Forward Error Correction schemes. It doesn't play nice with 802.16-2004. [See article at link above for good graphic table of WiBro capabilities] [Preparation for the] official, WiMAX interoperability tests began this July at the CETECOM laboratory in Spain. Certified gear is expected to be available at the end of this year. But it may not matter much for consumers. WiMax, in the [strictly] 802.16-2004 flavor, is going to be a pt-to-pt backhaul solution. The money shot is on CPE and basestations that are Mobile WiMax compatible. The July 2005 802 Plenary Session was held at the Hyatt Regency San Francisco, July 17-22, 2005. The agenda and session format can be viewed at the link above. 802.16-2004: Lost In Translation? [Insert for article above] The 802.16-2004 got a range boost using subchannelization. That allows clients to use fewer carriers (upstream) resulting in higher EIRP and better range. A Scalable OFDM carrier is the next frontier for Mobile WiMax, but it "breaks" compatibility with 802.16-2004. Moving to mobilized WiMax (and S-COFDM) will not be the smooth transition everyone was hoping for. Plain vanilla 802.16-2004 isn't compatible with the new Mobile WiMax/WiBro standard. That's forcing chip companies to create "enhanced" 802.16-2004 WiMax chips, with a foot in each camp. Two mobile standards (IEEE 802.16e & WiBro) agreed to merge to avoid political, technical and economic headaches. Intel wanted the Scalable COFDM technology while South Korea wanted early entree into the WiMax market. Intel and LG are now working together to bring Korea's 2.3 GHz WiBro system to the United States. And elements of WiBro, specifically scalable COFDM, are being incorporated into Intel chips. Samsung and LG Electronics lead the world in WiBro - and may have first mover advantage in Mobile WiMax. Intel could not afford to loose China. Lost in translation may be IEEE 802.20 and the original IEEE 802.16-2004 standard. The mobilized IEEE 802.20 "standard" now appears to offer few advantages over the WiBro/WiMax "e" juggernaut. Cellular support is tepid as EV-DO and HSPDA loom. Flarion is promoting their FLASH-OFDM system as the "defacto" standard. Meanwhile, "enhanced" WiMax chips, with the ability to interoperate with Scalable COFDM (for better range), may mean the plain vanilla 802.16-2004 standard could be quickly obsolete. << - Eric -

To: Eric L who wrote (43)	8/27/2005 2:46:12 PM
From: Eric L	Respond to of 86

Ovum Update on the WiMAX Roadmap (and Backwards Compatability) ..... >> An Update on the WiMAX Roadmap Julian Grivolas Ovum July 2005 ovum.com All the marketing hype surrounding WiMAX has undoubtedly contributed to industry awareness of the technology, but it has also created unrealistic expectations for both performance and product availability for such an immature market. This 'over-hype' led to disappointment when the WiMAX Forum delayed the launch of the WiMAX certification process initially scheduled for January 2005 to July 2005. Consequently, there will not be any WiMAX-certified products until late 2005, and in the interim period, all the so-called'pre-WiMAX' equipment will be proprietary developments based on IEEE 802.16-2004. However, April 2005 saw many significant announcements for the WiMAX industry: • ETSI and the WiMAX Forum agreed to work together on the development of common standards and certification tests • WiMAX Forum Certification processes will begin in July 2005, initially focusing on IEEE 802.16-2004 equipment based on two profiles in the 3.5GHz band, with 3.5MHz channelisation using TDD and FDD. The WiMAX Forum expects more profiles in 2006 depending on market demand and vendor product submission, and has also confirmed its commitment to backward compatibility. • Three heavyweights in the chip industry, namely Intel, Texas Instruments and Fujitsu, launched production in volume of their 802.16-2004 chipsets. This opens a window for lower-cost 802.16-2004-based CPE and infrastructure equipment. The WiMAX industry may have clarified its product roadmap for equipment based on 802.16-2004, but this does not mean the main operators are automatically going to widely deploy the technology. First, because no certified products will be available in volume before late 2005, but above all because of the unclear migration path towards 802.16e, the mobile version of WiMAX. Even for WiMAX backers, and Intel in particular, the long-term success of WiMAX relies on 802.16e to enable the 'personal broadband vision' concept. Here WiMAX is envisioned as a complement to 'beyond 3G technologies' rather than a competitor, at least in developed countries. The problem is that several issues remain unsolved - the main one is the final specification of the IEEE 802.16e standard itself. Initially, the IEEE standard body was expecting to use the OFDM 256 FFT physical layer specification already adopted by the WiMAX Forum for the fixed version of WiMAX. This decision aimed for backward compatibility between the two versions through a smooth software-based upgrade. However, the integration of WiBro into the 802.16e process brings new technical approaches, especially concerning the PHY layer with the introduction of the Scalable OFDMA (SOFDMA) technique. The only problem is that SOFDMA is not backward compatible with OFDM256, which is the basis of current 'pre-WiMAX' equipment, even in the same frequency band. On top of that, there are also some issues regarding the spectrum used by the first certified profiles to support mobile WiMAX. Given all these uncertainties, service providers, in particular incumbents, who have ambitions in mobile WiMAX are adopting a 'wait and see' strategy. A clarification of the 802.16e roadmap appears to be critical for the take-off of the technology for these players. Operators mainly targeting the fixed application business will accelerate their deployment strategies once standardised indoor and outdoor solutions are available in volume and at lower prices. These operators could position themselves as • Suppliers of connectivity solutions for enterprises (WiMAX as an alternative to T1/SDSL) • Wholesalers using WiMAX as the technology of choice for backhauling WiFi and cellular • Suppliers of Internet access services targeting consumer/enterprise markets in remote areas where no wired networks are deployed or where wired technologies' performances are poor. Nevertheless, the support of mobility remains a critical differentiator for WiMAX, and the business case for these early adopters would be significantly empowered by mobile capability. << - Eric -