3.1. Benefits of Standardization for Wireless Tech.

What is a good standard? What is the wireless standard? Why standards need to be established and released? What are the benefits of standardization for wireless technologies? Which aspects should be concentrated on when setting institutions? Such many questions come out in everybody's mind to the people and organizations who may concern. That's because standard issues are significant for the progress and improvement of wireless technology. Scientific research and technologies update are faster and faster which should be combined with society application and people using. This section will discuss some relevant issues and explain the concerned questions.

Standards no only based on technologies, but also based on how the groups work on institutional establishment, economy, marketing, generalization, services, maintenance, and amendment, etc. Here more attention will be paid to others except technology.

Actually, related information about making a good standard is rarely given in literatures on standardization. This may be because the fact that this problem will change according to standardization ethics so that it depends on many other aspects. Different organizations for different purposes represent their special understanding of a good standard. However, normal properties should apply to a good standard as below [1]:

• The standard meets the needs of the users or the interested parties
• The standard is available to the users in time
• The standard is formulated in a way that is comprehensible and free of contradiction in terms of its scope
• The standard can be implemented by the users
• The standard does not contradict other existing standards. However, this point is open to discussion because occasionally competition supports differing standards. In this way, the better standard is intended to assert itself, and innovation is not obstructed.
• The standard should tend to be more performance-based than prescriptive
• The standard is sufficiently distributed amongst the users and is applied to an adequate extent by all interested parties. A standard that is not applied has no right to exist
• If the development of a standard starts at an early stage, the lower the problem ability will be that economic interests might have already formed among the participnts

Referring to many cases previously and currently, most of them suprisingly fulfill the requirements above. Especially for technical standards, such as wireless standards, they also are similar to the basic concept and situation of the properties of a good standard. Wireless standard based on the wireless technologies, and for the purpose of unifying the application and utilizing technologically, some specialized and professional organizations dedicate to the development of wireless standards such as IEEE 802 group, ETSI, WiMAX Forum and so on.

Economically, there are no doubts that standards have positive economic influences on economic performance. In the complicated word of standards, different types of standards exert their own affects on economic issues. In fact, the interdependence between standards and technical change which is widely agreed among economists as one of the most important economic fundamentals. It has been shown that standards can exert influences on technical change in a complicated situation. Generally speaking, standards are pro-effective for technical changes. Moreover, emphasis is placed on the interrelation between standards and competition which is believed to be the driving force of a market economy. That means the impacts of standards on competitive market structure are influenced by the dynamics and speed of technical change. Standards exert a positive influence on the transactions of goods and services across borders.

The benefits of a standard also can be discussed for some aspects such as equipment vendors, consumers, service providers, component makers especially for wireless standards. Firstly, for equipment vendors, standards-based, common platform fosters rapid innovation and addition of new components and services. They concentrate on specialization. Secondly, consumers receive services in areas that were previously out of the broadband loop, this happen in developing countries with little infrastructure while in developed countries to rural and hard-to-service areas. More players in the market translate into more choices for receiving broadband access services. For service providers, thirdly, common plantform drives down costs, fosters healthy competition and engourages innovations and wireless systems significantly reduce operator investment risk. Last but no least, for component makers, standardization creates a volume opportunities for chip set vendors/silicon suppliers.

Entire and reasonable organization structure is tremendously advantaged for standard development. For instance, IEEE 802 LAN/MAN standards committee develops Local Area Network standards and Metropolitan Area Network. IEEE 802.16 group focus on MAN and not only the standard based on IEEE technologically but also be certified by WiMAX Forum, assigned spectrum by WiSOA (WiMAX Spectrum Owners Alliance), and relate to other liaisons and external organizations such as WCA (Wireless Communications Association International), ITU (International Telecommunication Union), ETSI (European Telecommunications Standards Institute), CCSA (China Communications Standards Association), etc. On the other hand, WiMAX standard also combine with other companies including Motorola, Nokia, Samsung, Cisco, Hutton and so on and service providers such as Clearwire, Sprint Nextel, etc. So that global network supporting for 802.16 (WiMAX) will fully improve the progress of this standard.

Overall, standardization have overwhelming positive performance for technology, service and network of the sophisticated technical application. That's why I am talking about WiMAX standard dimension as my topic in this blog.

References:
[1] Wilfried Hesser, Axel Czaya, Nicole Riemer, "Development of Standards" (Lecture Material of the course)
[2] http://www.wimaxforum.org/
[3] http://www.ieee802.org/16/

2.3. Comparison of WiMAX, Wi-Fi (mainly) and Others

In the past years, Wi-Fi is the most popular topic in wireless area and this standard and relevant technology had been used widely in practice. Here I will compare WiMAX and Wi-Fi simply. There comparison frequently happens because these two standards both based on IEEE 802 group and with similar names.

Wi-Fi based on IEEE 802.11 which is a set of standards for wireless local area network (WLAN) computer communication, developed by the IEEE LAN/MAN Standards Committee (IEEE 802) in the 5 GHz and 2.4 GHz public spectrum bands. Although the terms 802.11 and Wi-Fi are often used interchangeably, the Wi-Fi Alliance uses the term "Wi-Fi" to define a slightly different set of overlapping standards. Actually, the WiMAX Forum is keen to present 802.16 as complementary to the local area IEEE standard, 802.11 or Wi-Fi. However, according to there different applications and characteristics, these two should be used in different concrete situation. Following words will give there comparison in some special aspects.

WiMAX

Spectrum license: uses licensed spectrum typically; it’s also possible to use unlicensed spectrum.

Coverage: Optimized for outdoor non-line of sight; supports mesh networks; supports advanced smart antenna.

Range: long-range system; covers many kilometers; optimized up to 50km; point to multipoint (or multipoint to multipoint); handles many users widely spread out, tolerant of greater multipath delay spread up to 10ms; PHY and MAC designed for multimile range.

QoS: uses a mechanism based on setting up connections between the Base Station and the user device, each connection is based on specific scheduling algorithms which means that QoS parameters can be guaranteed for each flow; grant request MAC; designed to support voice and video from the start; supports differentiated service level; TDD/FDD/HFDD – symmetric or asymmetric; centrally enforced QoS.

Performance: Bandwidth 10/20 MHz, 1.75/3.5/7/14 Hz, 3/6 MHz; maximum data rate 70Mbps; Maximum 5 bps/Hz

Scalability: highly scalable from what are called “femto”-scale remote stations to multi-sector 'maxi' scale base that handle complex task of management and mobile handoff functions and include MIMO-AAS smart antenna susystems; channel bandwidths can be chosen by operator for sectorization; scalable independent of bandwidth with 1.5 MHz to 20 MHz width channels; MAC supports thousands of users.

Wi-Fi

Spectrum license: uses license-exempt (unlicensed) spectrum only to provide access to a network.

Coverage: typically covers only the network operator’s own property, be used by an end user to access their own network which may or may not be connected to the internet; optimized for indoor use; no mesh support within standards; smart antenna support proprietary.

Range: shorter range system, typically hundreds of meters, optimized for 100 meters (now is more than 100m); point to point; No ’near-far’ compensation; designed for indoor multipath delay spread up to 0.8ms; PHY and MAC optimized for 100m range; range can be extended but then MAC non-standard

QoS: introduced a QoS mechanism similar to fixed Ethernet where packets can receive different priorities based on their tags which means that QoS is relative between packets/flows as opposed to guaranteed; contention-based MAC; standard can not guarantee latency for voice or video; no allowance for differentiated levels of service on a per user basis; TDD only-asymmetric.

Performance: bandwidth 20 MHz; maximum data rate 54 Mbps; maximum 2.7 bps/Hz.

Scalability: wide 20 MHz channels; MAC supports tens of users

WiMAX is a serious threat to 3G because of its broadband capabilities, distance capabilities and ability to support voice effectively with full Qos. This makes it an alternative to cellular in a way that Wi-Fi can never be, so that while operators are integrating Wi-Fi into their offerings with some alacrity, looking to control both the licensed spectrum and the unlicensed hotspots, they will have more problems accommodating WiMAX. But as with Wi-Fi, it will be better for them to cannibalize their own network than let independents do it for them, especially as economics and performance demands force them to incorporate IP into their systems. Handset makers such as Nokia will be banking on this as they develop smartphones that support WiMAX as well as 3G. A standards-based long distance technology will avoid many of the problems of high upfront costs, lack of roaming and unreliability that those ahead of their time pioneers encountered, but it will still need to gain market share rapidly before 3G takes an unassailable hold. Given the current slow progress of 3G, especially in Europe, and the unusually streamlined process of commercialising WiMAX, the carriers are indulging in wishful thinking when they say nothing can catch up with cellular.

Due to the ease and low cost with which Wi-Fi can be deployed, it is sometimes used to provide Internet access to third parties within a single room or building available to the provider, often informally, and sometimes as part of a business relationship. For example, many coffee shops, hotels, and transportation hubs contain Wi-Fi access points providing access to the Internet for customers.

Although we just focus on the comparison between WiMAX and Wi-Fi because the comparison of these two is most considerable, we can also connect WiMAX (802.16) with other standards such as 802.15 (Bluetooth), 802.20 WAN, RFID, etc. The figure (source: [1]) below indicates the comparison and relationship of these standards.

The first figure above shows the two directions of PAN to WAN, ETSI HiperMAN is a competing standards to WiMAX and details of such these kinds of competing standards will be discuss combine with WiMAX in the next section of blog.

References:

[1] Dr. Mohammad Shakouri, "The Impact of 802.16 Technology Will Enable Ubiquitous Delivery of Broadband Wireless Services", WiMAX Forum.

[2] http://en.wikipedia.org/wiki/WiMAX

2.2. Fundamental Technical Specifications of WiMAX

Technical specifications of WiMAX will be introduced in this section. WiMAX is Worldwide Interoperability for Microwave Access which based on IEEE 802.16 standard. Firstly, I will go indepth to the fundamental technologies of WiMAX; secondly, frequency selection is interesting to be focused on; thirdly related techniques of required bandwith practically is going to be indicated; then, spectrum theme for WiMAX about increasing capacity and service demand will be shown and technical improvements or addings in the standards will be mentioned; finally, a typical WiMAX network configuration will be illustrated.

Fundamental Technologies

This part is specially for the fundamental technologies of WiMAX. As we know, 802.16 operates at up to 124Mbps in the 28MHz channel (in 10-66GHz), 802.16a at 70Mbps in lower frequency, 2-11GHz spectrum. It will specify two flavors of OFDM systems: one simply identified as OFDM, the other OFDMA.

OFDM
Frequency division multiplexing (FDM) is a technology that transmits multiple signals simultaneously over a single transmission path, such as a cable or wireless system. Each signal travels within its own unique frequency range (carrier), which is modulated by the data (text, voice, video, etc.). Orthogonal FDM's (OFDM) spread spectrum technique distributes the data over a large number of carriers that are spaced apart at precise frequencies. This spacing provides the "orthogonality" in this technique which prevents the demodulators from seeing frequencies other than their own. The benefits of OFDM are high spectral efficiency, resiliency to RF interference, and lower multi-path distortion. This is useful because in a typical terrestrial broadcasting scenario there are multipath-channels.

OFDM has been recently recognized as an excellent method for high speed bi-directional wireless data communication. Its history dates back to the 1960s, but it has recently become popular because economical integrated circuits that can perform the high speed digital operations necessary have become available. OFDM effectively squeezes multiple modulated carriers tightly together, reducing the required bandwidth but keeping the modulated signals orthogonal so they do not interfere with each other. Today, the technology is used in such systems as asymmetric digital subscriber line (ADSL) as well as wireless systems such as IEEE 802.11a/g (64 subcarriers) and IEEE 802.16 (WiMAX). In OFDM we have 256 sub-carriers with 192 data sub-carriers, 8 pilot sub-carriers and 56 nulls. In its most basic form, each data sub-carrier could be on or off to indicate a one or zero bit of information. However, either phase shift keying (PSK) or quadrature amplitude modulation (QAM) is typically employed to increase the data throughput. So in this case, a data stream would be split into n (192) parallel data streams, each at 1/n (1/192) of the original rate. Each stream is then mapped to the individual data sub-carrier and modulated using either PSK or QAM. Pilot subcarriers provide a reference to minimize frequency and phase shifts during the transmission while null carriers allow for guard bands and the DC carrier (center frequency).All subcarriers are sent at the same time. Actually, 802.16a has three PHY options: an OFDM with 256 sub-carriers – the only option supported in Europe by the ETSI, whose rival HiperMAN standard is likely to be subsumed into WiMAX; OFDMA, with 2048 sub-carriers; and a single carrier option for vendors that think they can beat multipath problems in this mode. OFDM will almost certainly become dominant in all wireless technologies including cellular and its industry body, the OFDM Forum, is a founder member of WiMAX Forum.

OFDMA
Orthogonal frequency division multiple access (OFDMA) allows some sub-carriers to be assigned to different users. For example, sub-carriers 1, 3 and 7 can be assigned to user 1 and sub-carriers 2, 5 and 9 to user 2. These groups of sub-carriers are known as sub-channels. Scalable OFDMA allows smaller FFT sizes to improve performance (efficiency) for lower bandwidth channels. This applies to IEEE 802.16-2004 which can now reduce the FFT size from 4096 to 128 to handle channel bandwidths ranging from 1.25–20 MHz. This allows sub-carrier spacing to remain constant independent of bandwidth which reduces complexity while also allowing larger FFT for increased performance with wide channels.

A great advantage of OFDM and OFDMA modulation is tolerance to multipath propagation and selective fading. It can overcome its negative influence utilizing parallel, slower bandwidth nature. This has made it not only ideal for such new technologies like WiMAX, but also currently one of the prime technologies being considered for use in future fourth generation (4G) networks.

802.16-2004 was updated by 802.16e-2005 in 2005 and uses scalable orthogonal frequency-division multiple access (SOFDMA) as opposed to the OFDM version with 256 sub-carriers (of which 200 are used) in 802.16d

PHY Layer
Physical layer was defined for a wide range of frequency from 2 up to 66 GHz. In sub-range 10-66 GHz system there is an assumption of Line-Of-Sight propagation. In this scheme single carrier modulation was chosen, because of low complexity of system. Downlink channel is shared among users with TDM signals. Subscriber unit are being allocated individual time slots. Access in uplink is being realized with TDMA. Channel bandwidths are 20 or 25 MHz in USA and 28MHz (Europe). Duplex can be realized with either TDD or FDD scheme. In the 2-11 GHz bands communication can be achieved for licensed and non-licensed bands. The communication is also available in NLOS conditions. The 802.16a Draft3 air interface specification describes three formats: Single Carrier modulation (SC), OFDM with 256 point transform, and OFDMA with 2048 point transform. The Forward Error Correction (FEC) is used with Reed-Salomon Codes GF(256). It is also paried inner block convolutional code to robustly transmit critical data, like Frame Control or Initial Access.

MIMO
More advanced versions, including 802.16e, also bring Multiple Antenna Support through Multiple-input multiple-output communications (MIMO), referring to WiMAX MIMO. This brings potential benefits in terms of coverage, self installation, power consumption, frequency re-use and bandwidth efficiency. 802.16e also adds a capability for full mobility support. The WiMAX certification allows vendors with 802.16d products to sell their equipment as WiMAX certified, thus ensuring a level of interoperability with other certified products, as long as they fit the same profile.

Dynamic Frequency Selection in Unlicensed Spectrum

Mesh
Mesh Mode is an optional topology for subscriber-to-subscriber communication in non-line of sight 802.16a. It is included in the standard to allow overlapping, ad hoc networks in the unlicensed spectrum and extend the edges of the WMAN’s range at low cost. Mesh support has recently been extended into the licensed bands too. Although it has highly complex topology and messaging, mesh is a good alternative to the usual NLOS, as it scales well and addresses license exempt interference. It allows a community to be densely seeded with WiMAX connections at low cost, with robust communications as there are multiple paths for traffic to take

Spectral efficiency
Spectrum efficiency measures the maximum total amount of data that can be carriedby a cell per unit of time, normalized with the occupied system bandwidth. For anygiven traffic load per user, spectral efficiency can be used to determine the numberof users a cell can support. For example, 802.16-2004 (fixed) has a spectral efficiency of 3.7 (bit/s)/Hertz, and other 3.5–4G wireless systems offer spectral efficiencies that are similar to within a few tenths of a percent. The notable advantage of WiMAX comes from combining SOFDMA with smart antenna technologies. This multiplies the effective spectral efficiency through multiple reuse and smart network deployment topologies. The direct use of frequency domain organization simplifies designs using MIMO-AAS compared to CDMA/WCDMA methods, resulting in more-effective systems

Protocol independent core
WiMAX can transport IPv4, IPv6, Ethernet or ATM and others, supporting multiple services simultaneously and with quality of service.

Bandwidth on Demand

Bandwidth is significant aspect in WiMAX. Related consideration such as Quality of Service, adaptive modulation, and duplexing, etc. are need to be taken into account.

QoS
The ‘b’ extension to 802.16 is concerned with quality of service (QoS), which enables NLOS operation without severe distortion of the signal from buildings, weather and vehicles. It also supports intelligent prioritization of different forms of traffic according to its urgency. Mechanisms in the Wireless MAN MAC provide for differentiated QoS to support the different needs of different applications. For instance, voice and video require low latency but tolerate some error rate, while most data applications must be error-free, but can cope with latency. The standard accommodates these different transmissions by using appropriate features in the MAC layer, which is more efficient than doing so in layers of control overlaid on the MAC. Later amendments such as 802.16-2004, 802.16e are also based on this scheme.

Adaptive Modulation
Many systems in the past decade have involved fixed modulation, offering a trade-off between higher order modulation for high data rates, but requiring optimal links, or more robust lower orders that will only operate at low data rates. 802.16a supports adaptive modulation, balancing different data rates and link quality and adjusting the modulation method almost instantaneously for optimum data transfer and to make most efficient use of bandwidth.

FDD and TDD
The standard also supports both frequency and time division duplexing (FDD and TDD) to enable interoperability with cellular and other wireless systems. FDD, the legacy duplexing method, has been widely deployed in cellular telephony. It requires two channel pairs, one for transmission and one for reception, with some frequency separation between them to mitigate self-interference. In regulatory environments where structured channel pairs do not exist, TDD uses a single channel for both upstream and downstream transmissions, dynamically allocating bandwidth depending on traffic requirements.

Future Spectrum for WiMAX – More Room and Service Options

Additional bands are being considered today by different regions around the world for the deployment of WiMAX and other similar broadband wireless access services. In Japan the 5.47GHz – 5.725GHz band is being considered for future use. The North American market is indicating some interest in deploying WiMAX in the 4.9GHz broad-spectrum public safety band. There is even some interest in using lower frequency bands such as the licensed 800MHz and he unlicensed 915MHz ISM bands for WiMAX and similar types of services and deployments. The WiMAX standard is set to bring the long-awaited spectral efficiency and throughput to meet users’ needs for combined mobility, voice services and high data rates. It will enable access for more users due to its non-line-of-sight capability, lower deployment costs, wide range capability and penetration into the mass consumer market with lower CPE costs as a result of standardization and interoperability. Since October 2007, the Radiocommunication Sector of the International Telecommunication Union (ITU-R) has decided to include WiMAX technology in the IMT-2000 set of standards. This enables spectrum owners (specifically in the 2.5-2.69 GHz band at this stage) to use Mobile WiMAX equipment in any country that recognizes the IMT-2000.

Technical Improvement & Development of Standards

The current WiMAX incarnation, Mobile WiMAX, is based upon IEEE Std 802.16e-2005, approved in December 2005. It is a supplement to the IEEE Std 802.16-2004, and so the actual standard is 802.16-2004 as amended by 802.16e-2005 — the specifications need to be read together to understand them.

IEEE Std 802.16-2004 addresses only fixed systems. It replaced IEEE Standards 802.16-2001, 802.16c-2002, and 802.16a-2003.

IEEE 802.16e-2005 improves upon IEEE 802.16-2004 by [2]:

- Adding support for mobility (soft and hard handover between base stations). This is seen as one of the most important aspects of 802.16e-2005, and is the very basis of 'Mobile WiMAX'.

- Scaling of the Fast Fourier Transform (FFT) to the channel bandwidth in order to keep the carrier spacing constant across different channel bandwidths (typically 1.25 MHz, 5 MHz, 10 MHz or 20 MHz). Constant carrier spacing results in a higher spectrum efficiency in wide channels, and a cost reduction in narrow channels. Also known as Scalable OFDMA (SOFDMA). Other bands not multiples of 1.25 MHz are defined in the standard, but because the allowed FFT subcarrier numbers are only 128, 512, 1024 and 2048, other frequency bands will not have exactly the same carrier spacing, which might not be optimal for implementations.

- Improving NLOS coverage by utilizing advanced antenna diversity schemes, and hybrid-Automatic Retransmission Request (HARQ).

- Improving capacity and coverage by introducing Adaptive Antenna Systems (AAS) and Multiple Input Multiple Output (MIMO) technology

- Increasing system gain by use of denser sub-channelization, thereby improving indoor penetration

- Introducing high-performance coding techniques such as Turbo Coding and Low-Density Parity Check (LDPC), enhancing security and NLOS performance

- Introducing downlink sub-channelization, allowing administrators to trade coverage for capacity or vice versa

- Enhanced Fast Fourier Transform algorithm can tolerate larger delay spreads, increasing resistance to multipath interference

- Adding an extra QoS class (enhanced real-time Polling Service) more appropriate for VoIP applications.

802.16d vendors point out that fixed WiMAX offers the benefit of available commercial products and implementations optimized for fixed access. It is a popular standard among alternative service providers and operators in developing areas due to its low cost of deployment and advanced performance in a fixed environment. Fixed WiMAX is also seen as a potential standard for backhaul of wireless base stations such as cellular, Wi-Fi or even Mobile WiMAX. SOFDMA (used in 802.16e-2005) and OFDM256 (802.16d) are not compatible so most equipment will have to be replaced if an operator wants or needs to move to the later standard. However, some manufacturers are planning to provide a migration path for older equipment to SOFDMA compatibility which would ease the transition for those networks which have already made the OFDM256 investment. Intel provides a dual-mode 802.16-2004 802.16-2005 chipset for subscriber units. This affects a relatively small number users and operators.

Typical WiMAX Network Configuration



The figure (Source:[3]) above shows a typical WiMAX network congiguration solution. Where SS is subscriber station; CPE is Customer premises equipment such as router; MS and BS are Mobile station and base station respectively; ASN is access service network; CSN, obviously, is connectivity service network; AAA is authentication, authorization and accounting entity; HA is home agent; and DHCP is dynamic host control protocol.This typical structure is basd on Fujitsu WiMAX solution of Japan.


Overall, this section mainly focuses on the technology details of WiMAX. With the technologies improvements and development, the standards will also be amended based on the core techniques. In the coming section, I would like to show the relationship with other wireless technologies.

Reference:
[1] Carl Eklund, Roger B. Marks, Kenneth L. Stanwood and Stanley Wang, "IEEE Standard 802.16:A Technical Overview of theWirelessMAN™ Air Interface forBroadband Wireless Access", IEEE Communications Magazine, June 2002.
[2] http://en.wikipedia.org/wiki/WiMAX
[3] http://www.fujitsu.com/img/TELCOM/wireless/wimax/wimax_network.jpg

2.1. Progress and amendments of IEEE 802.16 standards

In this section, the history progress of IEEE 802.16 standards by now will be indicated and some details information of the amendments will be given, including superceded standards, terminated projects, active standards, darfts under development and amendments in pre-draft stage. These materials will illustrate the development of 802.16 standards more legible and intuitionistic. Also we may have a global view of the standards.

Superceded Standards

IEEE 802.16–2001
802.16 standard was approved in December 2001. It delivered a standard for point to multipoint Broadband Wireless transmission in the 10-66 GHz band, with only a line-of-sight (LOS) capability. It uses a single carrier (SC) physical (PHY) standard. It was latterly released at April 2002.

IEEE 802.16a–2003
802.16a was an amendment to 802.16 and delivered a point to multipoint capability in the 2-11 GHz band. For this to be of use, it also required a non-line-of-sight (NLOS) capability, and the PHY standard was therefore extended to include Orthogonal Frequency Division Multiplex (OFDM) and Orthogonal Frequency Division Multiple Access (OFDMA). 802.16a was ratified in January 2003 and was intended to provide "last mile" fixed broadband access.

IEEE 802.16c–2002
802.16c which was latterly released at 15 January 2003, was an amendment to 802.16, delivered a system profile for the 10-66 GHz 802.16 standard


Terminated Projects

IEEE P802.16d
In September 2003, a revision project called 802.16d commenced aiming to align the standard with aspects of the European Telecommunications Standards Institute (ETSI) HIPERMAN standard as well as lay down conformance and test specifications. This project concluded in 2004 with the release of 802.16-2004 which superseded the earlier 802.16 documents, including the a/b/c amendments.

IEEE P802.16-2004/Cor2
This project was latterly released at 22 May 2007.


Active Standards

IEEE 802.16–2004
Revision of IEEE 802.16 including IEEE 802.16-2001, IEEE 802.16c-2002, and IEEE 802.16a-2003) developed by Task Group d under the temporary draft designation "P802.16-REVd".

IEEE 802.16e–2005
An amendment to 802.16-2004, IEEE 802.16e-2005 (formerly known as IEEE 802.16e), addressing mobility, was concluded in 2005. This implemented a number of enhancements to 802.16-2004, including better support for Quality of Service and the use of Scalable OFDMA, and is sometimes called “Mobile WiMAX”, after the WIMAX forum for interoperability. It’s also called Mobile 802.16.

IEEE 802.16f–2005
Management Information Base, an amendment to IEEE 802.16, latterly released at 1 December 2005.

IEEE 802.16g–2007
Management Plane Procedures and Services, an amendment to IEEE 802.16, latterly released at 10 April 2007.

IEEE 802.16–2004/Cor1-2005
Corrigendum to IEEE 802.16, published along with 802.16e – 2005, latterly released at 28 February 2006.

IEEE 802.16.2–2004
Revision of 802.16.2-2001, latterly released at 17 March 2004.

IEEE 802.16/Conformance01-2003, IEEE 802.16/Conformance02-2003, IEEE 802.16/Conformance03-2004 and IEEE 802.16/Conformance04-2006, were latterly released at 18 August 2003, 25 February 2004, 25 June 2004, and 15 January 2007 respectively.

IEEE 802.16k–2007
Bridging of 802.16, an amendment to 802.1D (as previously amended by 802.17a), developed by Network Management Task Group, latterly released at 14 August 2007.


Drafts Under Development

IEEE 802.16h
Improved Coexistence Mechanisms for License-Exempt Operation, project to amend IEEE 802.16, in development by License-Exempt Task Group, latterly released at 18 May 2008.

IEEE 802.16i
Mobile Management Information Base, project to amend IEEE 802.16, in development by Network Management Task Group, latterly released at 2 October 2007.

IEEE 802.16j
Multihop Relay Specification, project to amend IEEE 802.16, in development by Relay Task Group, latterly released at 30 May 2008.

IEEE 802.16Rev2
Consolidate 802.16-2004, 802.16e, 802.16f, 802.16g and possibly 802.16i into a new document. This work will result in the second revision of IEEE 802.16, following 802.16-2001 and 802.16-2004. Consolidate 802.16-2004, 802.16e-2005, 802.16-2004/Cor1-2005, 802.16f-2005 and possibly 802.16g and 802.16i, incorporating the P802.16-2004/Cor2 draft.


Amendments in Pre-Draft Stage

IEEE 802.16m
802.16 Task Group m (TGm) is chartered to develop an amendment to IEEE standard 802.16 under PAR P802.16m and the relevant Five Criteria Statement statement. The PAR addresses “Air Interface for Fixed and Mobile broadband Wireless Access Systems - Advanced Air Interface” and was approved by the IEEE-SA standards Board on 6 December 2006. Data rates of 100 Mbit/s for mobile applications and 1 Gbit/s for fixed applications, cellular, macro and micro cell coverage, with currently no restrictions on the RF bandwidth (which is expected to be 20 MHz or higher). The proposed work plan would allow completion of the standard by December 2009 for approval by March 2010.

Reference:
[1] http://www.ieee802.org/16/published.html
[2] Carl Eklund, Roger B. Marks, Subbu Ponnuswamy, Kenneth L. Stanwood, Nico J.M. Van Waes, "WirelessMAN: Inside the IEEE 802.16 Standard for Wireless Metropolitan Area Networks", IEEE Press, 2006.

1. Introduction of IEEE 802.16

I remember that when I was a college student in Zhejiang University three years ago, the first time I got the words IEEE 802.16 from my supervisor in the laborotary, I felt that this technique will be tremendously promising and fast developed in the near future. Because at that time, I was working in the project which was related to IEEE 802.11 and the telecomunication receiver algorithm about MIMO-OFDM which was considered as 4G technology. Actually, after that, I would often concern about the progress and information of its standards. So here I would give the introduction of IEEE 802.16 standards as the beginning of the assignment.

Since July 1999, the IEEE 802.16 Working Group on Broadband Wireless Access Standards, which was established by IEEE Standards Board, aims to prepare formal specifications for the global deployment of broadband Wireless Metropolitan Area Networks. The Workgroup is a unit of the IEEE 802 LAN/MAN Standards Committee. A related future technology Mobile Broadband Wireless Access (MBWA) is under development in IEEE 802.20.

Although the 802.16 family of standards is officially called WirelessMAN, it has been dubbed “WiMAX” (from "Worldwide Interoperability for Microwave Access") by an industry group called the WiMAX Forum. The mission of the Forum is to promote and certify compatibility and interoperability of broadband wireless products.

IEEE 802.16 provides solutions that are more economical than wireline alternatives. The standards set the stage for a revolution in reliable, high-speed network access in the first mile (also known as the "last mile") by homes and enterprises. The Working Group has completed, and is currently enhancing, two IEEE Standards. The IEEE 802.16 WirelessMAN Standard ("Air Interface for Fixed Broadband Wireless Access Systems") addresses Wireless Metropolitan Area Networks. Following a two-year effort, the initial standard, covering systems between 10 and 66 GHz, was approved in December 2001 for publication. It delivered a standard for point to multipoint Broadband Wireless transmission in the 10-66 GHz band, with only a line-of-sight (LOS) capability. It uses a single carrier (SC) physical (PHY) standard.

802.16a was an amendment to 802.16 and delivered a point to multipoint capability in the 2-11 GHz band. For this to be of use, it also required a non-line-of-sight (NLOS) capability, and the PHY standard was therefore extended to include Orthogonal Frequency Division Multiplex (OFDM) and Orthogonal Frequency Division Multiple Access (OFDMA). 802.16a was ratified in January 2003 and was intended to provide "last mile" fixed broadband access. 802.16c, a further amendment to 802.16, delivered a system profile for the 10-66 GHz 802.16 standard. In September 2003, a revision project called 802.16d commenced aiming to align the standard with aspects of the European Telecommunications Standards Institute (ETSI) HIPERMAN standard as well as lay down conformance and test specifications. This project concluded in 2004 with the release of 802.16-2004 which superseded the earlier 802.16 documents, including the a/b/c amendments. An amendment to 802.16-2004, IEEE 802.16e-2005 (formerly known as IEEE 802.16e), addressing mobility, was concluded in 2005. This implemented a number of enhancements to 802.16-2004, including better support for Quality of Service and the use of Scalable OFDMA, and is sometimes called “Mobile WiMAX”, after the WIMAX forum for interoperability.

In this blog, I would like to introduce the information of IEEE 802.16 standards, and the specification of WiMAX which is popular nowadays all around the world; sumarize the history and progress of amendaments of the standards; analysize the situation in some areas such as China, etc.; and explore the research and development in the future.

Reference
[1] http://www.ieee802.org/16/
[2] http://en.wikipedia.org/wiki/IEEE_802.16

0. The Blog

Hello, This blog is specially for the course 0EL70 "Regulations and standards for wireless communication" in the year 2007-2008. According to the topic and my exploration, I will update it frequently with the artical structure. Thanks and enjoy!



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