WiMax
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Worldwide Interoperability for Microwave Access (WiMAX) is a family of
wireless broadband Wireless broadband is telecommunications technology that provides high-speed wireless Internet access or computer networking access over a wide area. The term comprises both fixed and mobile broadband. The term broadband Originally the word ...
communication standards based on the IEEE 802.16 set of standards, which provide physical layer (PHY) and
media access control In IEEE 802 LAN/MAN standards, the medium access control (MAC, also called media access control) sublayer is the layer that controls the hardware responsible for interaction with the wired, optical or wireless transmission medium. The MAC sublay ...
(MAC) options. The WiMAX Forum was formed in June 2001 to promote conformity and interoperability, including the definition of system profiles for commercial vendors. The forum describes WiMAX as "a standards-based technology enabling the delivery of last mile
wireless broadband access Wireless broadband is telecommunications technology that provides high-speed wireless Internet access or computer networking access over a wide area. The term comprises both fixed and mobile broadband. The term broadband Originally the word "b ...
as an alternative to
cable Cable may refer to: Mechanical * Nautical cable, an assembly of three or more ropes woven against the weave of the ropes, rendering it virtually waterproof * Wire rope, a type of rope that consists of several strands of metal wire laid into a hel ...
and
DSL Digital subscriber line (DSL; originally digital subscriber loop) is a family of technologies that are used to transmit digital data over telephone lines. In telecommunications marketing, the term DSL is widely understood to mean asymmetric dig ...
". IEEE 802.16m or WirelessMAN-Advanced was a candidate for 4G, in competition with the
LTE Advanced LTE Advanced (LTE+) is a mobile communication standard and a major enhancement of the LTE (telecommunication), Long Term Evolution (LTE) standard. It was formally submitted as a candidate 4G to ITU-T in late 2009 as meeting the requirements of t ...
standard. WiMAX was initially designed to provide 30 to 40 megabit-per-second data rates, with the 2011 update providing up to 1 Gbit/s for fixed stations. WiMAX release 2.1, popularly branded as WiMAX 2+, is a backwards-compatible transition from previous WiMAX generations. It is compatible and interoperable with
TD-LTE In telecommunications, long-term evolution (LTE) is a standard for wireless broadband communication for mobile devices and data terminals, based on the GSM/EDGE and UMTS/ HSPA standards. It improves on those standards' capacity and speed by us ...
.


Terminology

WiMAX refers to interoperable implementations of the IEEE 802.16 family of wireless-networks standards ratified by the WiMAX Forum. (Similarly,
Wi-Fi Wi-Fi () is a family of wireless network protocols, based on the IEEE 802.11 family of standards, which are commonly used for local area networking of devices and Internet access, allowing nearby digital devices to exchange data by radio wave ...
refers to interoperable implementations of the
IEEE 802.11 IEEE 802.11 is part of the IEEE 802 set of local area network (LAN) technical standards, and specifies the set of media access control (MAC) and physical layer (PHY) protocols for implementing wireless local area network (WLAN) computer commun ...
Wireless LAN standards certified by the
Wi-Fi Alliance The Wi-Fi Alliance is a non-profit organization that owns the Wi-Fi trademark. Manufacturers may use the trademark to brand products certified for Wi-Fi interoperability. History Early 802.11 products suffered from interoperability problems be ...
.) WiMAX Forum certification allows vendors to sell fixed or mobile products as WiMAX certified, thus ensuring a level of interoperability with other certified products, as long as they fit the same profile. The original IEEE 802.16 standard (now called "Fixed WiMAX") was published in 2001. WiMAX adopted some of its technology from
WiBro WiBro (''wireless broadband'') is a wireless broadband Internet technology developed by the South Korean telecoms industry. WiBro is the South Korean service name for IEEE 802.16e (mobile WiMAX) international standard. By the end of 2012, the ...
, a service marketed in Korea. Mobile WiMAX (originally based on 802.16e-2005) is the revision that was deployed in many countries and is the basis for future revisions such as 802.16m-2011. WiMAX was sometimes referred to as "Wi-Fi on steroids" and can be used for a number of applications including broadband connections, cellular backhaul,
hotspots Hotspot, Hot Spot or Hot spot may refer to: Places * Hot Spot, Kentucky, a community in the United States Arts, entertainment, and media Fictional entities * Hot Spot (comics), a name for the DC Comics character Isaiah Crockett * Hot Spot (Tra ...
, etc. It is similar to
Long-range Wi-Fi Long-range Wi-Fi is used for low-cost, unregulated point-to-point computer network connections, as an alternative to other fixed wireless, cellular networks or satellite Internet access. Wi-Fi networks have a range that's limited by the freque ...
, but it can enable usage at much greater distances.


Uses of WiMAX

The scalable physical layer architecture that allows for data rate to scale easily with available channel bandwidth and range of WiMAX make it suitable for the following potential applications: * Providing portable mobile broadband connectivity across cities and countries through various devices. * Providing a wireless alternative to cable and
digital subscriber line Digital subscriber line (DSL; originally digital subscriber loop) is a family of technologies that are used to transmit digital data over telephone lines. In telecommunications marketing, the term DSL is widely understood to mean asymmetric di ...
(DSL) for " last mile" broadband access. * Providing data, telecommunications (VoIP) and
IPTV Internet Protocol television (IPTV) is the delivery of television content over Internet Protocol (IP) networks. This is in contrast to delivery through traditional terrestrial, satellite, and cable television formats. Unlike downloaded media, ...
services (
triple play In baseball, a triple play (denoted as TP in baseball statistics) is the act of making three outs during the same play. There have only been 733 triple plays in Major League Baseball (MLB) since 1876, an average of just over five per season. Th ...
). * Providing Internet connectivity as part of a
business continuity Business continuity may be defined as "the capability of an organization to continue the delivery of products or services at pre-defined acceptable levels following a disruptive incident", and business continuity planning (or business continuity a ...
plan. * Smart grids and metering.


Internet access

WiMAX can provide at-home or mobile
Internet access Internet access is the ability of individuals and organizations to connect to the Internet using computer terminals, computers, and other devices; and to access services such as email and the World Wide Web. Internet access is sold by Internet ...
across whole cities or countries. In many cases, this has resulted in competition in markets which typically only had access through an existing incumbent DSL (or similar) operator. Additionally, given the relatively low costs associated with the deployment of a WiMAX network (in comparison with 3G,
HSDPA High Speed Packet Access (HSPA) is an amalgamation of two mobile protocols—High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA)—that extends and improves the performance of existing 3G mobile telecommunic ...
,
xDSL Digital subscriber line (DSL; originally digital subscriber loop) is a family of technologies that are used to transmit digital data over telephone lines. In telecommunications marketing, the term DSL is widely understood to mean asymmetric d ...
, HFC or
FTTx Fiber to the ''x'' (FTTX; also spelled "fibre") or fiber in the loop is a generic term for any broadband network architecture using optical fiber to provide all or part of the local loop used for last mile telecommunications. As fiber op ...
), it is now economically viable to provide last-mile broadband Internet access in remote locations.


Middle-mile backhaul to fiber networks

Mobile WiMAX was a replacement candidate for
cellular phone A mobile phone, cellular phone, cell phone, cellphone, handphone, hand phone or pocket phone, sometimes shortened to simply mobile, cell, or just phone, is a portable telephone that can make and receive calls over a radio frequency link while ...
technologies such as
GSM The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such ...
and
CDMA Code-division multiple access (CDMA) is a channel access method used by various radio communication technologies. CDMA is an example of multiple access, where several transmitters can send information simultaneously over a single communicatio ...
, or can be used as an overlay to increase capacity. Fixed WiMAX is also considered as a wireless backhaul technology for 2G, 3G, and 4G networks in both developed and developing nations. In North America, backhaul for urban operations is typically provided via one or more
copper wire Copper has been used in electrical wiring since the invention of the electromagnet and the telegraph in the 1820s. The invention of the telephone in 1876 created further demand for copper wire as an electrical conductor. Copper is the electr ...
line connections, whereas remote cellular operations are sometimes backhauled via satellite. In other regions, urban and rural backhaul is usually provided by
microwave link Microwave transmission is the transmission of information by electromagnetic waves with wavelengths in the microwave frequency range of 300MHz to 300GHz(1 m - 1 mm wavelength) of the electromagnetic spectrum. Microwave signals are normally lim ...
s. (The exception to this is where the network is operated by an incumbent with ready access to the copper network.) WiMAX has more substantial backhaul bandwidth requirements than legacy cellular applications. Consequently, the use of wireless microwave backhaul is on the rise in North America and existing microwave backhaul links in all regions are being upgraded. Capacities of between 34 Mbit/s and 1 Gbit/s are routinely being deployed with latencies in the order of 1 ms. In many cases, operators are aggregating sites using wireless technology and then presenting traffic on to fiber networks where convenient. WiMAX in this application competes with
microwave radio Microwave transmission is the transmission of information by electromagnetic waves with wavelengths in the microwave frequency range of 300MHz to 300GHz(1 m - 1 mm wavelength) of the electromagnetic spectrum. Microwave signals are normally limi ...
, E-line and simple extension of the fiber network itself.


Triple-play

WiMAX directly supports the technologies that make triple-play service offerings possible (such as
quality of service Quality of service (QoS) is the description or measurement of the overall performance of a service, such as a telephony or computer network, or a cloud computing service, particularly the performance seen by the users of the network. To quantitat ...
and
multicast In computer networking, multicast is group communication where data transmission is addressed to a group of destination computers simultaneously. Multicast can be one-to-many or many-to-many distribution. Multicast should not be confused with ...
). These are inherent to the WiMAX standard rather than being added on as
carrier Ethernet Carrier Ethernet is a marketing term for extensions to Ethernet for communications service providers that utilize Ethernet technology in their networks. Background Ethernet has a long history. It has become dominant in enterprise networks. This d ...
is to
Ethernet Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...
. On May 7, 2008, in the United States,
Sprint Nextel Sprint Corporation was an American telecommunications company. Before it Merger of Sprint Corporation and T-Mobile US, merged with T-Mobile US on April 1, 2020, it was the fourth-largest mobile network operator in the United States, serving 54.3 ...
,
Google Google LLC () is an American multinational technology company focusing on search engine technology, online advertising, cloud computing, computer software, quantum computing, e-commerce, artificial intelligence, and consumer electronics. ...
,
Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 seri ...
,
Comcast Comcast Corporation (formerly known as American Cable Systems and Comcast Holdings),Before the AT&T merger in 2001, the parent company was Comcast Holdings Corporation. Comcast Holdings Corporation now refers to a subsidiary of Comcast Corpora ...
, Bright House, and
Time Warner Warner Media, LLC ( traded as WarnerMedia) was an American multinational mass media and entertainment conglomerate. It was headquartered at the 30 Hudson Yards complex in New York City, United States. It was originally established in 1972 by ...
announced a pooling of an average of 120 MHz of spectrum and merged with
Clearwire Clearwire Corporation (stylized as clearw˙re) was a telecommunications operator which provided mobile and fixed wireless broadband communications services to retail and wholesale customers in the United States, Belgium, Ireland and Spain. Clearw ...
to market the service. The new company hoped to benefit from combined services offerings and network resources as a springboard past its competitors. The cable companies were expected to provide media services to other partners while gaining access to the wireless network as a
Mobile virtual network operator A mobile virtual network operator (MVNO) is a wireless communications services provider that does not own the wireless network infrastructure over which it provides services to its customers. An MVNO enters into a business agreement with a mobil ...
to provide triple-play services. Some wireless industry analysts, such as Ken Dulaney and Todd Kort at Gartner, were skeptical how the deal would work out: Although fixed-mobile convergence had been a recognized factor in the industry, prior attempts to form partnerships among wireless and cable companies had generally failed to lead to significant benefits for the participants. Other analysts at IDC favored the deal, pointing out that as wireless progresses to higher bandwidth, it inevitably competes more directly with cable, DSL and fiber, inspiring competitors into collaboration. Also, as wireless broadband networks grow denser and usage habits shift, the need for increased backhaul and media services accelerate, therefore the opportunity to leverage high bandwidth assets was expected to increase.


Aviation

The Aeronautical Mobile Airport Communication System (AeroMACS) is a wireless broadband network for the airport surface intended to link the control tower, aircraft, and fixed assets. In 2007, AeroMACS obtained a worldwide frequency allocation in the 5 GHz aviation band. As of 2018, there were 25 AeroMACS deployments in 8 countries, with at least another 25 deployments planned.


Support for TDD and FDD

IEEE 802.16REVd and IEEE 802.16e standards support both
time-division duplex A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow ...
ing and
frequency-division duplex A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow ...
ing as well as a half duplex FDD, that allows for a low cost implementation.


Connecting

Devices that provide connectivity to a WiMAX network are known as subscriber stations (SS). Portable units include handsets (similar to cellular
smartphone A smartphone is a portable computer device that combines mobile telephone and computing functions into one unit. They are distinguished from feature phones by their stronger hardware capabilities and extensive mobile operating systems, whic ...
s); PC peripherals (PC Cards or USB dongles); and embedded devices in laptops, which are now available for Wi-Fi services. In addition, there is much emphasis by operators on consumer electronics devices such as Gaming consoles, MP3 players and similar devices. WiMAX is more similar to Wi-Fi than to other 3G cellular technologies. The WiMAX Forum website provides a list of certified devices. However, this is not a complete list of devices available as certified modules are embedded into laptops, MIDs ( Mobile Internet devices), and other private labeled devices.


Gateways

WiMAX gateway devices are available as both indoor and outdoor versions from manufacturers including Vecima Networks,
Alvarion Alvarion Technologies is a global provider of autonomous Wi-Fi networks designed with self-organizing capabilities for carrier-grade Wi-Fi, enterprise connectivity, smart city planning, smart hospitality, connected campuses, and connected even ...
, Airspan,
ZyXEL Zyxel Communications Corporation, a subsidiary of Unizyx Holding Corporation (), is a Taiwanese multinational broadband provider headquartered in the Hsinchu Science Park, Taiwan. The company was founded in 1989 by Dr Shun-I Chu, and has three r ...
,
Huawei Huawei Technologies Co., Ltd. ( ; ) is a Chinese multinational technology corporation headquartered in Shenzhen, Guangdong, China. It designs, develops, produces and sells telecommunications equipment, consumer electronics and various smar ...
, and
Motorola Motorola, Inc. () was an American Multinational corporation, multinational telecommunications company based in Schaumburg, Illinois, United States. After having lost $4.3 billion from 2007 to 2009, the company split into two independent p ...
. The
list of WiMAX networks The following is a list of WiMAX networks. Standards * IEEE 802.16 - called fixed WiMAX because of static connection without handover. * IEEE 802.16e - called mobile WiMAX because it allows handovers between base stations. * IEEE 802.16m - advan ...
and WiMAX Forum provide more links to specific vendors, products and installations. Many of the WiMAX gateways that are offered by manufactures such as these are stand-alone self-install indoor units. Such devices typically sit near the customer's window with the best signal, and provide: * An integrated Wi-Fi access point to provide the WiMAX Internet connectivity to multiple devices throughout the home or business. *
Ethernet Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...
ports to connect directly to a computer, router,
printer Printer may refer to: Technology * Printer (publishing), a person or a company * Printer (computing), a hardware device * Optical printer for motion picture films People * Nariman Printer (fl. c. 1940), Indian journalist and activist * James ...
or DVR on a local wired network. * One or two analog telephone jacks to connect a land-line phone and take advantage of VoIP. Indoor gateways are convenient, but radio losses mean that the subscriber may need to be significantly closer to the WiMAX base station than with professionally installed external units. Outdoor units are roughly the size of a laptop PC, and their installation is comparable to the installation of a residential
satellite dish A satellite dish is a dish-shaped type of parabolic antenna designed to receive or transmit information by radio waves to or from a communication satellite A communications satellite is an artificial satellite that relays and amplifies radi ...
. A higher-
gain Gain or GAIN may refer to: Science and technology * Gain (electronics), an electronics and signal processing term * Antenna gain * Gain (laser), the amplification involved in laser emission * Gain (projection screens) * Information gain in de ...
directional outdoor unit will generally result in greatly increased range and throughput but with the obvious loss of practical mobility of the unit.


External modems

USB Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad ...
can provide connectivity to a WiMAX network through a
dongle A dongle is a small piece of computer hardware that connects to a port on another device to provide it with additional functionality, or enable a pass-through to such a device that adds functionality. In computing, the term was initially synonym ...
. Generally these devices are connected to a notebook or net book computer. Dongles typically have omnidirectional antennas which are of lower gain compared to other devices. As such these devices are best used in areas of good coverage.


Mobile phones

HTC announced the first WiMAX enabled
mobile phone A mobile phone, cellular phone, cell phone, cellphone, handphone, hand phone or pocket phone, sometimes shortened to simply mobile, cell, or just phone, is a portable telephone that can make and receive calls over a radio frequency link whil ...
, the Max 4G, on November 12, 2008. The device was only available to certain markets in Russia on the
Yota Yota (russian: Йота) is a Russian mobile phone brand and mobile broadband manufacturer. Yota is a trademark of Skartel LLC. On 9 May 2012, Yota's WiMAX was replaced by its LTE network. In September 2012, 4G networks were launched in the ...
network until 2010. HTC and
Sprint Nextel Sprint Corporation was an American telecommunications company. Before it Merger of Sprint Corporation and T-Mobile US, merged with T-Mobile US on April 1, 2020, it was the fourth-largest mobile network operator in the United States, serving 54.3 ...
released the second WiMAX enabled mobile phone, the
HTC Evo 4G The HTC Evo 4G (trademarked in capitals as EVO 4G, also marketed as HTC EVO WiMAX ISW11HT in Japan) is a smartphone developed by HTC Corporation and marketed as Sprint's flagship Android smartphone, running on its WiMAX network. The smartphone w ...
, March 23, 2010 at the CTIA conference in Las Vegas. The device, made available on June 4, 2010, is capable of both EV-DO(3G) and WiMAX(pre-4G) as well as simultaneous data & voice sessions. Sprint Nextel announced at CES 2012 that it will no longer be offering devices using the WiMAX technology due to financial circumstances, instead, along with its network partner
Clearwire Clearwire Corporation (stylized as clearw˙re) was a telecommunications operator which provided mobile and fixed wireless broadband communications services to retail and wholesale customers in the United States, Belgium, Ireland and Spain. Clearw ...
, Sprint Nextel rolled out a 4G network having decided to shift and utilize LTE 4G technology instead.


Technical information


The IEEE 802.16 standard

WiMAX is based upon
IEEE The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operation ...
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. Thus, these specifications need to be considered together. IEEE 802.16e-2005 improves upon IEEE 802.16-2004 by: * 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 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. Carrier spacing is 10.94 kHz. * Advanced
antenna diversity Antenna diversity, also known as space diversity or spatial diversity, is any one of several wireless diversity schemes that uses two or more antennas to improve the quality and reliability of a wireless link. Often, especially in urban and ind ...
schemes, and hybrid automatic repeat-request (HARQ) * Adaptive antenna systems (AAS) and
MIMO In radio, multiple-input and multiple-output, or MIMO (), is a method for multiplying the capacity of a radio link using multiple transmission and receiving antennas to exploit multipath propagation. MIMO has become an essential element of wi ...
technology * Denser sub-channelization, thereby improving indoor penetration * Intro and low-density parity check (LDPC) * Introducing downlink sub-channelization, allowing administrators to trade coverage for capacity or vice versa * Adding an extra
quality of service Quality of service (QoS) is the description or measurement of the overall performance of a service, such as a telephony or computer network, or a cloud computing service, particularly the performance seen by the users of the network. To quantitat ...
(QoS) class for VoIP applications SOFDMA (used in 802.16e-2005) and OFDM256 (802.16d) are not compatible thus equipment will have to be replaced if an operator is to move to the later standard (e.g., Fixed WiMAX to Mobile WiMAX).


Physical layer

The original version of the standard on which WiMAX is based ( IEEE 802.16) specified a physical layer operating in the 10 to 66 GHz range. 802.16a, updated in 2004 to 802.16-2004, added specifications for the 2 to 11 GHz range. 802.16-2004 was updated by 802.16e-2005 in 2005 and uses scalable
orthogonal frequency-division multiple access Orthogonal frequency-division multiple access (OFDMA) is a multi-user version of the popular orthogonal frequency-division multiplexing (OFDM) digital modulation scheme. Multiple access is achieved in OFDMA by assigning subsets of subcarriers t ...
(SOFDMA), as opposed to the fixed orthogonal frequency-division multiplexing (OFDM) version with 256 sub-carriers (of which 200 are used) in 802.16d. More advanced versions, including 802.16e, also bring multiple antenna support through
MIMO In radio, multiple-input and multiple-output, or MIMO (), is a method for multiplying the capacity of a radio link using multiple transmission and receiving antennas to exploit multipath propagation. MIMO has become an essential element of wi ...
. (See
WiMAX MIMO WiMAX MIMO refers to the use of Multiple-input multiple-output communications (MIMO) technology on WiMAX, which is the technology brand name for the implementation of the standard IEEE 802.16. Background WiMAX WiMAX is the technology brand nam ...
) This brings potential benefits in terms of coverage, self installation, power consumption, frequency re-use and bandwidth efficiency. WiMax is the most energy-efficient pre-4G technique among LTE and HSPA+.


Media access control layer

The WiMAX MAC uses a
scheduling algorithm In computing, scheduling is the action of assigning ''resources'' to perform ''tasks''. The ''resources'' may be processors, network links or expansion cards. The ''tasks'' may be threads, processes or data flows. The scheduling activity is ca ...
for which the subscriber station needs to compete only once for initial entry into the network. After network entry is allowed, the subscriber station is allocated an access slot by the base station. The time slot can enlarge and contract, but remains assigned to the subscriber station, which means that other subscribers cannot use it. In addition to being stable under overload and over-subscription, the scheduling algorithm can also be more
bandwidth Bandwidth commonly refers to: * Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range * Bandwidth (computing), the rate of data transfer, bit rate or thr ...
efficient. The scheduling algorithm also allows the base station to control QoS parameters by balancing the time-slot assignments among the application needs of the subscriber station.


Specifications

As a standard intended to satisfy needs of next-generation data networks ( 4G), WiMAX is distinguished by its dynamic burst algorithm modulation adaptive to the physical environment the RF signal travels through. Modulation is chosen to be more spectrally efficient (more bits per
OFDM In telecommunications, orthogonal frequency-division multiplexing (OFDM) is a type of digital transmission and a method of encoding digital data on multiple carrier frequencies. OFDM has developed into a popular scheme for wideband digital commu ...
/ SOFDMA symbol). That is, when the bursts have a high signal strength and a high carrier to noise plus interference ratio (CINR), they can be more easily decoded using
digital signal processing Digital signal processing (DSP) is the use of digital processing, such as by computers or more specialized digital signal processors, to perform a wide variety of signal processing operations. The digital signals processed in this manner are ...
(DSP). In contrast, operating in less favorable environments for RF communication, the system automatically steps down to a more robust mode (burst profile) which means fewer bits per OFDM/SOFDMA symbol; with the advantage that power per bit is higher and therefore simpler accurate signal processing can be performed. Burst profiles are used inverse (algorithmically dynamic) to low signal attenuation; meaning throughput between clients and the base station is determined largely by distance. Maximum distance is achieved by the use of the most robust burst setting; that is, the profile with the largest MAC frame allocation trade-off requiring more symbols (a larger portion of the MAC frame) to be allocated in transmitting a given amount of data than if the client were closer to the base station. The client's MAC frame and their individual burst profiles are defined as well as the specific time allocation. However, even if this is done automatically then the practical deployment should avoid high interference and multipath environments. The reason for which is obviously that too much interference causes the network to function poorly and can also misrepresent the capability of the network. The system is complex to deploy as it is necessary to track not only the signal strength and CINR (as in systems like
GSM The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such ...
) but also how the available frequencies will be dynamically assigned (resulting in dynamic changes to the available bandwidth.) This could lead to cluttered frequencies with slow response times or lost frames. As a result, the system has to be initially designed in consensus with the base station product team to accurately project frequency use, interference, and general product functionality. The Asia-Pacific region has surpassed the North American region in terms of 4G broadband wireless subscribers. There were around 1.7 million pre-WiMAX and WiMAX customers in Asia – 29% of the overall market – compared to 1.4 million in the US and Canada.


Integration with an IP-based network

The WiMAX Forum has proposed an architecture that defines how a WiMAX network can be connected with an IP based core network, which is typically chosen by operators that serve as Internet Service Providers (ISP); Nevertheless, the WiMAX BS provide seamless integration capabilities with other types of architectures as with packet switched Mobile Networks. The WiMAX forum proposal defines a number of components, plus some of the interconnections (or reference points) between these, labeled R1 to R5 and R8: * SS/MS: the Subscriber Station/Mobile Station * ASN: the Access Service Network * BS: Base station, part of the ASN * ASN-GW: the ASN Gateway, part of the ASN * CSN: the Connectivity Service Network * HA: Home Agent, part of the CSN * AAA: Authentication, Authorization and Accounting Server, part of the CSN * NAP: a Network Access Provider * NSP: a Network Service Provider It is important to note that the functional architecture can be designed into various hardware configurations rather than fixed configurations. For example, the architecture is flexible enough to allow remote/mobile stations of varying scale and functionality and Base Stations of varying size – e.g. femto, pico, and mini BS as well as macros.


Spectrum allocation

There is no uniform global licensed spectrum for WiMAX, however the WiMAX Forum published three licensed spectrum profiles: 2.3 GHz, 2.5 GHz and 3.5 GHz, in an effort to drive standardisation and decrease cost. In the US, the biggest segment available was around 2.5 GHz, and is already assigned, primarily to
Sprint Nextel Sprint Corporation was an American telecommunications company. Before it Merger of Sprint Corporation and T-Mobile US, merged with T-Mobile US on April 1, 2020, it was the fourth-largest mobile network operator in the United States, serving 54.3 ...
and
Clearwire Clearwire Corporation (stylized as clearw˙re) was a telecommunications operator which provided mobile and fixed wireless broadband communications services to retail and wholesale customers in the United States, Belgium, Ireland and Spain. Clearw ...
. Elsewhere in the world, the most-likely bands used will be the Forum approved ones, with 2.3 GHz probably being most important in Asia. Some countries in Asia like
India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
and
Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
will use a mix of 2.5 GHz, 3.3 GHz and other frequencies.
Pakistan Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...
's Wateen Telecom uses 3.5 GHz. Analog TV bands (700 MHz) may become available, but await the complete digital television transition, and other uses have been suggested for that spectrum. In the USA the FCC auction for this spectrum began in January 2008 and, as a result, the biggest share of the spectrum went to Verizon Wireless and the next biggest to AT&T. Both of these companies stated their intention of supporting LTE, a technology which competes directly with WiMAX. EU commissioner
Viviane Reding Viviane Adélaïde Reding (born 27 April 1951) is a Luxembourgish politician and a former Member of the European Parliament (MEP) from Luxembourg. She is a member of the Christian Social People's Party, part of the European People's Party. She p ...
has suggested re-allocation of 500–800 MHz spectrum for wireless communication, including WiMAX. WiMAX profiles define channel size, TDD/FDD and other necessary attributes in order to have interoperating products. The current fixed profiles are defined for both TDD and FDD profiles. At this point, all of the mobile profiles are TDD only. The fixed profiles have channel sizes of 3.5 MHz, 5 MHz, 7 MHz and 10 MHz. The mobile profiles are 5 MHz, 8.75 MHz and 10 MHz. (Note: the 802.16 standard allows a far wider variety of channels, but only the above subsets are supported as WiMAX profiles.) Since October 2007, the Radio communication 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 WiMAX equipment in any country that recognizes the IMT-2000.


Inherent limitations

WiMAX cannot deliver 70 
Mbit/s In telecommunications, data-transfer rate is the average number of bits (bitrate), characters or symbols (baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are multi ...
over . Like all wireless technologies, WiMAX can operate at higher bitrates or over longer distances but not both. Operating at the maximum range of increases
bit error rate In digital transmission, the number of bit errors is the number of received bits of a data stream over a communication channel that have been altered due to noise, interference, distortion or bit synchronization errors. The bit error rate (BER) ...
and thus results in a much lower bitrate. Conversely, reducing the range (to under 1 km) allows a device to operate at higher bitrates. A citywide deployment of WiMAX in
Perth Perth is the capital and largest city of the Australian state of Western Australia. It is the fourth most populous city in Australia and Oceania, with a population of 2.1 million (80% of the state) living in Greater Perth in 2020. Perth is ...
,
Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
demonstrated that customers at the cell-edge with an indoor
Customer-premises equipment In telecommunications, a customer-premises equipment or customer-provided equipment (CPE) is any terminal and associated equipment located at a subscriber's premises and connected with a carrier's telecommunication circuit at the demarcation poi ...
(CPE) typically obtain speeds of around 1–4 Mbit/s, with users closer to the cell site obtaining speeds of up to 30 Mbit/s. Like all wireless systems, available bandwidth is shared between users in a given radio sector, so performance could deteriorate in the case of many active users in a single sector. However, with adequate capacity planning and the use of WiMAX's QoS, a minimum guaranteed throughput for each subscriber can be put in place. In practice, most users will have a range of 4–8 Mbit/s services and additional radio cards will be added to the base station to increase the number of users that may be served as required.


Silicon implementations

A number of specialized companies produced baseband ICs and integrated RFICs for WiMAX Subscriber Stations in the 2.3, 2.5 and 3.5 GHz bands (refer to 'Spectrum allocation' above). These companies include, but are not limited to, Beceem, Sequans, and PicoChip.


Comparison

Comparisons and confusion between WiMAX and
Wi-Fi Wi-Fi () is a family of wireless network protocols, based on the IEEE 802.11 family of standards, which are commonly used for local area networking of devices and Internet access, allowing nearby digital devices to exchange data by radio wave ...
are frequent, because both are related to wireless connectivity and Internet access. * WiMAX is a long range system, covering many kilometres, that uses licensed or unlicensed spectrum to deliver connection to a network, in most cases the Internet. * Wi-Fi uses the 2.4 GHz and 5 GHz radio frequency bands to provide access to a local network. * Wi-Fi is far more popular in end-user devices. * Wi-Fi runs on the
Media Access Control In IEEE 802 LAN/MAN standards, the medium access control (MAC, also called media access control) sublayer is the layer that controls the hardware responsible for interaction with the wired, optical or wireless transmission medium. The MAC sublay ...
's
CSMA/CA Carrier-sense multiple access with collision avoidance (CSMA/CA) in computer networking, is a network multiple access method in which carrier sensing is used, but nodes attempt to avoid collisions by beginning transmission only after the channel ...
protocol, which is connectionless and contention based, whereas WiMAX runs a connection-oriented MAC. * WiMAX and Wi-Fi have quite different QoS mechanisms: ** WiMAX uses a QoS mechanism based on connections between the base station and the user device. Each connection is based on specific scheduling algorithms. ** Wi-Fi uses
contention Contention or contentious may refer to: * Resource contention, in computer science, a conflict over access to a shared resource * Contention (telecommunications), a media access method to share a broadcast medium * Bus contention, an undesirable ...
access — all subscriber stations that wish to pass data through a
wireless access point In computer networking, a wireless access point (WAP), or more generally just access point (AP), is a networking hardware device that allows other Wi-Fi devices to connect to a wired network. As a standalone device, the AP may have a wired ...
(AP) are competing for the AP's attention on a random interrupt basis. This can cause subscriber stations distant from the AP to be repeatedly interrupted by closer stations, greatly reducing their throughput. * Both
IEEE 802.11 IEEE 802.11 is part of the IEEE 802 set of local area network (LAN) technical standards, and specifies the set of media access control (MAC) and physical layer (PHY) protocols for implementing wireless local area network (WLAN) computer commun ...
, which includes Wi-Fi, and IEEE 802.16, which includes WiMAX, define Peer-to-Peer (P2P) and
wireless ad hoc network A wireless ad hoc network (WANET) or mobile ad hoc network (MANET) is a decentralized type of wireless network. The network is ad hoc because it does not rely on a pre-existing infrastructure, such as routers in wired networks or access points ...
s, where an end user communicates to users or servers on another
Local Area Network A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building. By contrast, a wide area network (WAN) not only covers a larger ...
(LAN) using its access point or base station. However, 802.11 supports also direct ad hoc or peer to peer networking between end user devices without an access point while 802.16 end user devices must be in range of the base station. Although Wi-Fi and WiMAX are designed for different situations, they are complementary. WiMAX network operators typically provide a WiMAX Subscriber Unit that connects to the metropolitan WiMAX network and provides Wi-Fi connectivity within the home or business for computers and smartphones. This enables the user to place the WiMAX Subscriber Unit in the best reception area, such as a window, and have date access throughout their property.


Conformance testing

TTCN-3 TTCN-3 ''(Testing and Test Control Notation version 3)'' is a strongly typed testing language used in conformance testing of communicating systems. TTCN-3 is written by ETSI in the ES 201 873 series, and standardized by ITU-T in the Z.160 Series. TT ...
test specification language is used for the purposes of specifying conformance tests for WiMAX implementations. The WiMAX test suite is being developed by a Specialist Task Force at ETSI (STF 252).


Associations


WiMAX Forum

The WiMAX Forum is a non profit organization formed to promote the adoption of WiMAX compatible products and services. A major role for the organization is to certify the interoperability of WiMAX products. Those that pass conformance and interoperability testing achieve the "WiMAX Forum Certified" designation, and can display this mark on their products and marketing materials. Some vendors claim that their equipment is "WiMAX-ready", "WiMAX-compliant", or "pre-WiMAX", if they are not officially WiMAX Forum Certified. Another role of the WiMAX Forum is to promote the spread of knowledge about WiMAX. In order to do so, it has a certified training program that is currently offered in English and French. It also offers a series of member events and endorses some industry events.


WiMAX Spectrum Owners Alliance

WiSOA was the first global organization composed exclusively of owners of WiMAX spectrum with plans to deploy WiMAX technology in those bands. WiSOA focused on the regulation, commercialisation, and deployment of WiMAX spectrum in the 2.3–2.5 GHz and the 3.4–3.5 GHz ranges. WiSOA merged with the
Wireless Broadband Alliance Founded in 2003, the Wireless Broadband Alliance (WBA) undertakes programs and activities to address business and technical issues, as well as opportunities, for member companies. WBA work areas include standards development, industry guidelines, ...
in April 2008.


Telecommunications Industry Association

In 2011, the
Telecommunications Industry Association The Telecommunications Industry Association (TIA) is accredited by the American National Standards Institute (ANSI) to develop voluntary, consensus-based industry standards for a wide variety of Information and Communication Technologies (Inform ...
released three technical standards (TIA-1164, TIA-1143, and TIA-1140) that cover the air interface and core networking aspects of Wi-Max High-Rate Packet Data (HRPD) systems using a Mobile Station/Access Terminal (MS/AT) with a single transmitter.


Competing technologies

Within the marketplace, WiMAX's main competition came from existing, widely deployed wireless systems such as
Universal Mobile Telecommunications System The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the In ...
(UMTS),
CDMA2000 CDMA2000 (also known as C2K or IMT Multi‑Carrier (IMT‑MC)) is a family of 3G mobile technology standards for sending voice, data, and signaling data between mobile phones and cell sites. It is developed by 3GPP2 as a backwards-compatible ...
, existing Wi-Fi, mesh networking and eventually 4G (LTE). In the future, competition will be from the evolution of the major cellular standards to 4G, high-bandwidth, low-latency, all-IP networks with voice services built on top. The worldwide move to 4G for GSM/UMTS and AMPS/
TIA TIA or Tia may refer to: Aviation * Tampa International Airport, US, IATA code TPA * Texas International Airlines, US, ICAO code * Tirana International Airport Nënë Tereza, Albania, IATA code * Trans International Airlines, former U.S. airl ...
(including CDMA2000) is the
3GPP Long Term Evolution In telecommunications, long-term evolution (LTE) is a standard for wireless broadband communication for mobile devices and data terminals, based on the GSM/EDGE and UMTS/HSPA standards. It improves on those standards' capacity and speed by usi ...
(LTE) effort. The LTE Standard was finalized in December 2008, with the first commercial deployment of LTE carried out by TeliaSonera in Oslo and Stockholm in December, 2009. Henceforth, LTE saw rapidly increasing adoption by mobile carriers around the world. Although WiMax was much earlier to market than LTE, LTE was an upgrade and extension of previous 3G (GSM and CDMA) standards, whereas WiMax was a relatively new and different technology without a large user base. Ultimately, LTE won the war to become the 4G standard because mobile operators such as Verizon, AT&T, Vodafone, NTT, and Deutsche Telekom chose to extend their investments in know-how, equipment and spectrum from 3G to LTE, rather than adopt a new technology standard. It would never have been cost-effective for WiMax network operators to compete against fixed-line broadband networks based on 4G technologies. By 2009, most mobile operators began to realize that mobile connectivity (not fixed 802.16e) was the future, and that LTE was going to become the new worldwide mobile connectivity standard, so they chose to wait for LTE to develop rather than switch from 3G to WiMax. WiMax was a superior technology in terms of speed (roughly 25Mbit/s) for a few years (2005-2009), and it pioneered some new technologies such as MIMO. But the mobile version of WiMax (802.16m), intended to compete with GSM and CDMA technologies, was too little/too late in getting established, and by the time the LTE standard was finalized in December 2008, the fate of WiMax as a mobile solution was doomed and it was clear that LTE (not WiMax) would become the world's new 4G standard. The largest wireless broadband partner using WiMax, Clearwire, announced in 2008 that they would begin overlaying their existing WiMax network with LTE technology, which was necessary for Clearwire to obtain investments they needed to stay in business. In some areas of the world, the wide availability of UMTS and a general desire for standardization meant spectrum was not allocated for WiMAX: in July 2005, the EU-wide frequency allocation for WiMAX was blocked.


Harmonization

Early WirelessMAN standards, The European standard HiperMAN and Korean standard
WiBro WiBro (''wireless broadband'') is a wireless broadband Internet technology developed by the South Korean telecoms industry. WiBro is the South Korean service name for IEEE 802.16e (mobile WiMAX) international standard. By the end of 2012, the ...
were harmonized as part of WiMAX and are no longer seen as competition but as complementary. All networks now being deployed in South Korea, the home of the WiBro standard, are now WiMAX.


Comparison with other mobile Internet standards

The following table only shows peak rates which are potentially very misleading. In addition, the comparisons listed are not normalized by physical channel size (i.e., spectrum used to achieve the listed peak rates); this obfuscates spectral efficiency and net through-put capabilities of the different wireless technologies listed below.


Development

The IEEE 802.16m-2011 standard was the core technology for WiMAX 2. The IEEE 802.16m standard was submitted to the ITU for
IMT-Advanced International Mobile Telecommunications-Advanced (IMT-Advanced Standard) are the requirements issued by the ITU Radiocommunication Sector (ITU-R) of the International Telecommunication Union (ITU) in 2008 for what is marketed as 4G (or in Turke ...
standardization. IEEE 802.16m is one of the major candidates for IMT-Advanced technologies by ITU. Among many enhancements, IEEE 802.16m systems can provide four times faster data speed than the WiMAX Release 1. WiMAX Release 2 provided backward compatibility with Release 1. WiMAX operators could migrate from release 1 to release 2 by upgrading channel cards or software. The WiMAX 2 Collaboration Initiative was formed to help this transition. It was anticipated that using 4X2
MIMO In radio, multiple-input and multiple-output, or MIMO (), is a method for multiplying the capacity of a radio link using multiple transmission and receiving antennas to exploit multipath propagation. MIMO has become an essential element of wi ...
in the urban microcell scenario with only a single 20 MHz TDD channel available system wide, the 802.16m system can support both 120 Mbit/s downlink and 60 Mbit/s uplink per site simultaneously. It was expected that the WiMAX Release 2 would be available commercially in the 2011–2012 timeframe. WiMAX Release 2.1 was released in early-2010s which have broken compatibility with earlier WiMAX networks. Significant number of operators have migrated to the new standard that is compatible with TD-LTE by the end of 2010s.


Interference

A field test conducted in 2007 by SUIRG (Satellite Users Interference Reduction Group) with support from the U.S. Navy, the Global VSAT Forum, and several member organizations yielded results showing interference at 12 km when using the same channels for both the WiMAX systems and satellites in C-band.


Deployments

As of October 2010, the WiMAX Forum claimed over 592 WiMAX (fixed and mobile) networks deployed in over 148 countries, covering over 621 million people. By February 2011, the WiMAX Forum cited coverage of over 823 million people, and estimated coverage to over 1 billion people by the end of the year. Note that coverage means the offer of availability of WiMAX service to populations within various geographies, not the number of WiMAX subscribers. South Korea launched a WiMAX network in the second quarter of 2006. By the end of 2008 there were 350,000 WiMAX subscribers in Korea. Worldwide, by early 2010 WiMAX seemed to be ramping quickly relative to other available technologies, though access in North America lagged.
Yota Yota (russian: Йота) is a Russian mobile phone brand and mobile broadband manufacturer. Yota is a trademark of Skartel LLC. On 9 May 2012, Yota's WiMAX was replaced by its LTE network. In September 2012, 4G networks were launched in the ...
, the largest WiMAX network operator in the world in 4Q 2009, announced in May 2010 that it would move new network deployments to LTE and, subsequently, change its existing networks as well. A study published in September 2010 by Blycroft Publishing estimated 800 management contracts from 364 WiMAX operations worldwide offering active services (launched or still trading as opposed to just licensed and still to launch). The WiMAX Forum announced on Aug 16, 2011 that there were more than 20 million WiMAX subscribers worldwide, the high-water mark for this technology. http://wimaxforum.org/Page/News/PR/20110816_WiMAX_Subscriptions_Surpass_20_Million_Globally


See also

*
Category 5 cable Category 5 cable (Cat 5) is a twisted pair cable for computer networks. Since 2001, the variant commonly in use is the Category 5e specification (Cat 5e). The cable standard provides performance of up to 100 MHz and is ...
*
Cognitive radio A cognitive radio (CR) is a radio that can be programmed and configured dynamically to use the best wireless channels in its vicinity to avoid user interference and congestion. Such a radio automatically detects available channels in wireless spec ...
* Evolved HSPA *
High-Speed Packet Access High Speed Packet Access (HSPA) is an amalgamation of two mobile protocols—High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA)—that extends and improves the performance of existing 3G mobile telecommunicat ...
*
List of WiMAX networks The following is a list of WiMAX networks. Standards * IEEE 802.16 - called fixed WiMAX because of static connection without handover. * IEEE 802.16e - called mobile WiMAX because it allows handovers between base stations. * IEEE 802.16m - advan ...
*
Mobile broadband Mobile broadband is the marketing term for Wireless broadband, wireless Internet access via mobile networks. Access to the network can be made through a portable modem, wireless modem, or a Tablet computer, tablet/smartphone (possibly Tetherin ...
*
Mobile VoIP Mobile VoIP or simply mVoIP is an extension of mobility to a voice over IP network. Two types of communication are generally supported: cordless telephones using DECT or PCS protocols for short range or campus communications where all base stati ...
*
Municipal broadband Municipal broadband is broadband Internet access owned by public entities. Services are often provided either fully or partially by local governments to residents within certain areas or jurisdictions. Common connection technologies include unlice ...
* Packet Burst Broadband * Super Wi-Fi *
Switched mesh A switched mesh is a wireless mesh network that uses multiple radios to communicate via dedicated mesh backhaul links to each neighboring node in the mesh. Here all of the available bandwidth of each separate radio channel is dedicated to the l ...
*
WiBro WiBro (''wireless broadband'') is a wireless broadband Internet technology developed by the South Korean telecoms industry. WiBro is the South Korean service name for IEEE 802.16e (mobile WiMAX) international standard. By the end of 2012, the ...
(mobile WiMax in Korea) * Wireless bridge *
Wireless local loop Wireless local loop (WLL), is the use of a wireless communications link as the " last mile / first mile" connection for delivering plain old telephone service (POTS) or Internet access (marketed under the term "broadband") to telecommunications ...


Notes


References

* K. Fazel and S. Kaiser, ''Multi-Carrier and Spread Spectrum Systems: From OFDM and MC-CDMA to LTE and WiMAX'', 2nd Edition, John Wiley & Sons, 2008, * M. Ergen, ''Mobile Broadband – Including WiMAX and LTE'', Springer, NY, 2009 * Ramon Ray(2009) WiMax – Your Fast and Longer Distance WiFi has arrived. Personal Technology.


External links


Official page of the WiMAX Forum
{{DEFAULTSORT:Wimax IEEE 802 Metropolitan area networks Network access 2001 introductions 2001 establishments