WiMAX.com FAQ
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General WiMAX Info
1. What is WiMAX?
WiMAX is a coined term or acronym meaning worldwide interoperability for microwave access (WiMAX). What WiMAX is however at its heart is a standards initiative. Its purpose is to ensure that the broadband wireless radios manufactured for customer use interoperate from vendor to vendor. The primary advantages of the WiMAX standard are to enable the adoption of advanced radio features in a uniform fashion and reduce costs for all of the radios made by companies who are part of the WiMAX Forum, a standards body formed to ensure interoperability via testing.
2. Where did the idea of WiMAX come from?
Much of the credit for the formation of the WiMAX Forum and the notion of the WiMAX initiative must go to Intel and other founding members of the Forum, which committed themselves early to the process of creating a collaborative standards body. Intel recognized that for the broadband wireless industry (both fixed and mobile broadband wireless) to gain traction and wide acceptance that both hardware prices must decline and a consistent operating environment must be cemented into place. The key point of launch however, had to begin with the silicon chip manufacturers whose chip products would form the core of WiMAX technology value and capability.
Other technology standards for digital subscriber line (DSL) service and the Cable broadband industry (the DOCSIS standard) have been responsible for driving those technologies to wide acceptance. WiMAX itself is commonly mentioned in conjunction with the Institute for Electrical and Electronics Engineers (IEEE) IEEE 802.16 working group, which is tasked with defining the technological aspects and features that will be incorporated into WiMAX. The WiMAX Forum is a collaborative body geared to ensure compliance with the IEEE 802.16 standards and certified interoperability between radio vendors.
3. Is WiMAX new? When did it start?
WiMAX is new in terms of a standards initiative---and in particular the launch of numerous WiMAX technology supporting chipsets by Forum members. However, much of the technology being incorporated into the IEEE 802.16 technology set is existent in industry today. A number of best of breed broadband radio manufacturers already offered various elements being incorporated into WiMAX as proprietary technology. However, vendors rarely offered consistent iterations of radio modulation and other techniques---ensuring that solutions had to be single vendor specific.
This means that much of the technological capability of WiMAX is relatively mature. In fact the radio vendors who are members of the forum have deployed equipment in over 125 nations around the globe. The combination of these advanced technologies into a single standards package combined with new generation optimized chipsets and tested and certified interoperability between radio manufacturers deliver a robust and powerful technology with the inherent capability to match or exceed the performance and cost factors of other broadband technologies. This can all be achieved without traditional wireline tethers.
4. Is WiMAX safe?
Happily since much of the technology being utilized in the IEEE 802.16 standard (WiMAX standard) is widely deployed in limited fashion today there is a historical body of evidence supporting the safety of technologies used in upcoming WiMAX and WiMAX products. Microwave and other spectrum technologies enjoy over a hundred years of historical evidence of safety when prudently handled and configured. The amount of power allowed to deliver broadband wireless signal varies from frequency to frequency, however most are modest topping out around 40 watts. While certain basic precautions need to be taken when onsite at communications towers (i.e. standing directly in front of active microwave links at essentially zero range) the configurations for public use are understood and safe.
5. Why is WiMAX needed?
To answer this question it is important to understand the current state of technical fragmentation of the broadband wireless industry. Early broadband wireless systems began as extensions of indoor local area network (LAN) technology known as Wi-Fi or the 802.11b protocol. This standard has evolved into a ubiquitous and widely available standard used in short range hotspots all over the globe. However, the media access controller (MAC) and physical layer (PHY) specifications for this protocol are suboptimum for outdoor citywide wireless networks or metropolitan area networks (MAN). Recent updates and new standards such as 802.11g and 802.11a have improved these elements. However, once again these technologies are configured for best performance in small venues and at short range.
To compensate vendors developed proprietary MAC and PHY layers based on the root LAN standard of 802.11. Many of these systems are in use today and possess significant improvements in modulation scheme, polling technology and data transport that enable effective and modestly affordably citywide or rural wireless networks. However, none of these proprietary iterations of the technology are exactly the same. No two companies products will work with each other. This means that broadband wireless carriers must use base stations and customer premise equipment from the same vendor in any given city---which may not be the best solution in some geographic and radio frequency (RF) environments.
Some of these radio vendors were even forced to manufacture their own silicon chips to deliver technical improvements. The high costs for equipment resulting from this significantly slowed adoption of broadband wireless versus cheaper mass market technologies such as DSL and Cable modem service.
6. Why is WiMAX important for fixed broadband wireless?
WiMAX is arguably even more important for the fixed broadband wireless segment than mobile broadband at least internally to that industry. It seems clear that mobile broadband wireless holds the loftier long term monetary and customer growth potential. However, the fixed wireless segment has been fragmented essentially since its inception. There are no cohesive standards for outdoor metropolitan area networks beyond the adapted Wi-Fi technologies. Wi-Fi as a standard has been accepted in broad strokes by industry and the public. However, it is not a well conceived citywide technology. This industry has languished due to the inability to foment a cohesive technology strategy. Innovative features were restricted to individual brands with the result that numerous innovations if combined would have greatly improved results for all.
7. Why is WiMAX important for mobile broadband wireless?
Mobile broadband wireless or 3G has enjoyed a largely consistent standard, that being the code division multiple access (CDMA). However, the technology has been slow to mature into economically viable and affordable iterations. The bandwidth limitations have been significant and the adoption by carriers, particularly those utilizing GSM technology here in the US has been very slow. The sheer cost factor of the technology relative to its native spectral efficiency has not been conducive to adoption either. Estimates for the nation’s cellular carriers to build a comprehensive 3G network have ranged as high as $50 Billion. Mobile WiMAX offers a multi-spectrum standard with a better broadband technology concept that can significantly reduce costs improve spectral efficiency and deliver profitable services. The growth curve of the technology, partly due to the large number of chip and radio vendor firms driving the technology, should provide a much higher innovation curve for WiMAX. Internationally, broadband mobile wireless does enjoy greater acceptance. However, its gains leave much to be desired.
8. Will I have WiMAX service on my Cell Phone?
Eventually the answer is yes. Initially, expect to see Wi-Fi services converged with cellular devices. This early foray will teach both the fixed and wireless industries a great deal about technological co-existence. The long term vision for broadband wireless utilizing WiMAX is clearly one of multiple technologies that fill different niches in the service delivery universe. Clearly mobile voice products are mature, well-realized, profitable and stable. The truly mobile variant of this will likely be the most technically difficult to achieve and may never carry the bandwidth that linkages to faster fixed broadband can. But as products like VoIP gain acceptance the ability to utilize a fixed network while stationary and eventually a truly mobile broadband network (with somewhat different capabilities) will drive WiMAX/Cellular/and other technology convergences to the handheld cell phone. In the long run, WiMAX and other wireless technologies offer unprecedented flexibility to consumers.
9. Will WiMAX compete with Wi-Fi?
Clearly WiMAX and Wi-Fi are complementary technologies and will remain so for the foreseeable future. The widely available Wi-Fi technology used in hotspots in hotels, restaurants, airports and even larger Wi-Fi zones in some cities will continue to grow for many years. The wide availability of integrated 802.11b/g/a laptop radios provides a continually growing base of Wi-Fi consumers. The forum itself anticipates at least three waves of WiMAX gear during the next two years with affordable laptop based WiMAX radios coming in the third wave in years 2006-2007.
However, even these units will almost certainly be dual Wi-Fi/WiMAX or multi mode Wi-Fi/WiMAX/Cellular and will continue to be for several years thereafter. As the WiMAX standard grows and continues to gain acceptance and drive cost reductions new chipsets that incorporate the ability to function across multiple platforms will become more common with the MAN portion of this network technology slowly being converted to the more robust WiMAX systems as the business cases for hotspot venues merit. Basically this means that WiMAX users in a few years will be able to not only access Wi-Fi hotspot access at a café but could also have both portable and mobile citywide WiMAX access as well
However, other LAN technology standards such as Bluetooth, Ultrawideband and the emerging 802.11n specification that offer value in shorter range hotspot networks will both grow and necessitate chipsets and laptop radios that will eventually be able to seamlessly cross these shorter range data networks as well as cellular networks and WiMAX citywide networks. The WiMAX standard is a major part of the very bright vision of the broadband wireless future that flexibility like this promises.
10. Will WiMAX replace DSL and Cable?
It is important to remember that WiMAX is a global broadband wireless standard. The question of whether or not it could replace either DSL or Cable will vary from region to region. Many developing countries simply do not have the infrastructure to support either cable or DSL broadband technologies. In fact, many such countries are already widely using proprietary broadband wireless technologies. Even in such regions however, it is very unlikely that either Cable or DSL technologies would disappear. The business case and basic infrastructure often dictates that the cheapest solutions will predominate. In many areas even in very developing nations it may be cheaper to deploy Cable and DSL in the cities whereas WiMAX will dominate outside of major towns.
In the US both Cable and DSL are growing extremely fast but are not available for all customers. Rural and remote areas often lack broadband choices if any are available at all. When they are available the DSL or cable plant may only exist within the town limits with no service outside the city limits. This offers a compelling argument that low-cost WiMAX gear will leverage access to many new customers. WiMAX also promises a whole new level of data access flexibility that will be much less location specific for customers. This type of robust mobile, portable or fixed broadband access will be unprecedented.
In addition WiMAX will provide competitive options for carriers and users that will benefit traditional wireline carriers and customers by encouraging innovation and improved services.
11. How do I invest into WiMAX companies?
Vendors whose gear are certified as WiMAX interoperable solutions will be companies who have proven tested interoperable radios. For a list of the members of the WiMAX Forum go to www.wimaxforum.org.
Any investment in companies deploying WiMAX certified gear should be done with the prudence taken with any other type of investment.
12. Is WiMAX a mobile technology?
Yes. Even in its present so-called “Fixed WiMAX” version the technology already offers some mobile capability. However, the Forum is in the process of finalizing a standard for Mobile WiMAX or IEEE 802.16e. That standard is due to be completed probably during mid-2006.
The present technology is typically described as Fixed or sometimes portable or nomadic by some vendors. In most cases Fixed WiMAX or 802.16-2004 technology is probably best suited for fixed broadband wireless deployments. However, precursor WiMAX gear already provides portable and even mobile capability at modest scale today. There are International and US deployments where mobile applications are used daily with precursor gear. Most mobile applications on the precursor side however, have been focused around public safety needs such as police and fire with some notable exceptions.
It is common nowadays to see firms offering portability and for customers to use it in limited application. One firm Unwired Australia reports that about ten to fifteen percent of its customers do move their radios around downtown Sydney, Australia. Another firm in rural Iowa, Evertek has deployed mobile public safety access that it layers across its public net using encryption to maintain privacy.
13. What is WiMAX Mobile or 802.16e?
An emerging standard for WiMAX is that of Mobile WiMAX or 802.16e. This standard is still in flux. However, much of the primary work, particularly on the mandatory elements of the first product profile for the technology is already complete. Most of the remaining work resides in defining the optional elements that will go into the first version of the standard. The Forum intends to ratify the standard around the middle of 2006 with Interoperability testing to commence almost immediately.
With a bit of fortune, Mobile WiMAX products should be seen near the end of 2006, particularly Internationally. Mobile WiMAX appears to be the real darling of the Forum nowadays, likely mostly because of its potential to emerge as a real viable competitor to existing 3G technologies. This potential gained traction when South Korea elected to take a mobile Wi-MAX compatible standard called WiBro to market. This standard however, was based on a different formulation of OFDM than that chosen for the first product profile of 802.16-2004. The 802.16-2004 standard supports both formulations---however the OFDM 256FFT system was chosen for 802.16-2004. WiBro uses an OFDMA™ technology called 1K-FFT. Service for the WiBro standard is in the 2.3 GHz spectrum range. The Forum has already announced support for the WiBro standard. However, this did create a bit of a quandary in regards Fixed WiMAX. Since 802.16-2004 uses a different product profile the two standards products will not interoperate. This has forced Forum members to decide whether to support both product lines, update through 802.16-2004 or maintain existing proprietary tech and move toward adopting Mobile WiMAX as a separate product line. It appears that Mobile WiMAX is the favored recipient of the greatest number of confidence votes. Expect Mobile WiMAX to become the predominant WiMAX product offering in future. There is some suggestion that Mobile WiMAX may be primarily focused towards licensed spectrum product lines however.
WiMAX Technology & Standards
14. What is the Range of WiMAX?
The answer to this question probably generates more confusion than any other single aspect of WiMAX. It is common to see statements in the media describing WiMAX coverage extending 30 miles. In a strict technical sense (in some spectrum ranges) this is correct. In practice in the real world (and especially in the license-free bands) this is wildly overstated especially where non line of sight (NLOS) reception is concerned.
Due to a variety of factors explained in more detail below the average cell ranges for most WiMAX networks will likely boast 4-5 mile range (in NLOS capable frequencies) even through tree cover and building walls. Service ranges up to 10 miles (16 Kilometers) are very likely in line of sight (LOS) applications (once again depending upon frequency).
15. What is non line of sight (NLOS)? Does WiMAX possess NLOS capability?
WiMAX does possess NLOS capabilities, although how much and to what extent will vary depending on the spectrum bands being used. None line of sight indicates that the signal from a radio is received by either passing through impeding objects, such as tree tops, walls or even in some cases buildings or is received as a reflection from another building, body of water or land feature. In both cases the broadcasting radio is completely or at least partially obscured by some obstruction.
WiMAX radios utilize many of the best current techniques for receiving reflected signals from objects (such reflected signals are called multipath). Some of these incorporate antenna diversity techniques. The OFDM modulation favored by the first iteration of WiMAX actually takes advantage of reflected signals allowing radios to integrate multiple reflected signals to improve signal strength and accuracy.
Additionally, for WiMAX radios that are built for service in licensed bands (currently 2.5 GHz in the US and 2.5 GHz and 3.5 GHz Internationally - although other licensed spectrums below 11 GHz will be used in other profiles in future) the additional power allowed in these bands (typically around 40 Watts) permit signal to actually penetrate through some tree cover and building walls. There are limits posed by the physics of the spectrum range in question and power allotted. In general NLOS ranges in the 2.5 GHz band will mostly fall between 6-8 Kilometers (4-5 Miles). Expect additional technology to follow in coming years. The innovation curve for WiMAX should continue to be very steep.
16. What factors will most greatly affect range for WiMAX products?
Many factors affect range for any broadband wireless product. Some such factors include the terrain and density/height of tree cover. Hills and valleys can block or partially reflect signals. Bodies of water such as rivers and lakes are highly reflective of RF transmissions. Happily OFDM can often turn this to advantage---but not always. The RF shadow of large buildings can create dead spots directly behind them, particularly if license-free spectrums are being used (with their attendant lower power allotments). How busy the RF environment of a city or town can greatly degrade signals---meaning that properly designed and well thought out networks are always desired. The physics of radio transmission dictate that the greater the range between the base station and customer radio, the lower the amount of bandwidth that can be delivered, even in an extremely well-designed network. The climate can affect radio performance---despite this there are ubiquitous wireless networks deployed today with great success in frozen Alaskan oil fields.
No two cities are exactly alike in terms of the challenges and opportunities presented. In many respects broadband wireless remains very much an art form. However, this is also true for the cellular carriers most of us use daily. It can be done and well. Mobile broadband wireless will be more difficult. Achieving high QOS will be easier with fixed broadband wireless. Despite all of these challenges current broadband wireless is very effectively serving customers even in the most difficult environments.
17. What is the actual throughput (data transfer rate) of WiMAX Technology?
WiMAX supports very robust data throughput. The technology at theoretical maximums could support approximately 75 Mbps per channel (in a 20 MHz channel using 64QAM ¾ code rate). Real world performance will be considerably lower---perhaps maxing out around 45 Mbps/channel in some fixed broadband applications. Remember however, that service across this channel would be shared by multiple customers. Actual transmission capabilities on a per customer basis could vary widely depending on the carrier’s chosen customer base, which is actually an inherent strength because it can be defined by QOS in a deliberate fashion to offer different bandwidth capabilities to customers with different needs (and different budgets). Mobile WiMAX capabilities on a per customer basis will be lower in practical terms, but much better than competing 3G technologies. WiMAX is often cited to possess a spectral efficiency of 5 bps/Hz, which is very good compared to other broadband wireless technologies, especially 3G.
The modulation scheme whether QPRS, 16QAM, 65 QAM etc. (and their attendant code rate variations) deliver varying bandwidth capabilities by channel size. Like with most things wireless, the devil as they say is in the details. The good news is that pretty much all of the news is good in this regard relative to other broadband wireless and wireline competitors of WiMAX.
Many things affect transfer rate beyond simple radio capability. One major element being distance from the base station. The physics of radio cannot be avoided. Longer ranges result in lower bandwidth delivered. Also, the spectrum range (1.e. 20 MHz or other) that regulation defines as appropriate for different frequency bands will dictate bandwidth capabilities at least to some extent. Also remember that the RF and physical environment play a strong roll in throughput results. Essentially the real world blunts theoretical performance. Happily even with disclaimers centered around real world impediments, WiMAX throughput is excellent.
18. Does WiMAX have quality of service (QOS) capability?
Yes. WiMAX radios will support very robust QOS capabilities up to and incorporating asynchronous transfer mode (ATM) quality. The MAC itself is configured to handle IP traffic, Ethernet and ATM natively. The MAC was designed to even support future transport protocols not yet invented. Links can be dynamically configured based on link conditions. Basically this technique smoothes the balancing act between raw capacity and quality on the fly. It should improve capacity or spectral efficiency a great deal. There are a lot of elements of wireless transmission which affect the quality of signal---needs also vary depending on the type of data. For example, VoIP can tolerate some errors but must have low latencies (anything above 150 ms is a nonstarter) to operate. Video transmission is similar. Conversely data packets don’t need especially low latencies but cannot endure transmission errors.
WiMAX partly accomplishes this by assigning variable length Protocol Data Units (PDU)s, which is basically the data packet size in the Physical layer, that can be combined in bursts to reduce signaling overhead in the PHY layer. This is called adaptive modulation and is a sharp contract from the static modulation schemes of yesteryear. A similar technique is used for MAC signaling except they are called Service Data Units (SDU)s. Several other techniques are used for reducing signaling transmissions and to improve the polling or communications between radios. In the older 802.11b protocol for example, each radio and base station continues to signal and interact constantly with other radios (basically a CSMA/CD approach similar to Ethernet computer networks). This unfortunately results in packet collision, packet loss and a great deal of inefficient cross talk in a static mode.
WiMAX technology supports a variety of more efficient polling mechanisms that vendors and carriers can choose to use, including a defined contact cycle, grouping of radios into contact groups or even allowing customer radios to generate a brief signal indicating it needs a transmission cycle. All of these aspects, which are intended to solve multiple problems also result in much improved QOS capabilities. QOS is critical for delineating minimum bandwidth levels for VoIP sessions for example as well as other leading edge IP services.
Both common duplexing schemes are supported in WiMAX---those being FDD and TDD.
The frequency division duplexing (FDD) requires two parallel channels for send and receive. This method is a well-understood holdover from cellular technology. The newer time division duplexing (TDD) allows for dynamic and symmetric transmission of data across a single channel. Where and when either should be used often depend on the frequency and the vendor’s emphasis on particular strengths. It is not unfair to suggest that TDD is more likely to be widely utilized by WiMAX product vendors. Suffice it to say that multiple duplexing support adds significant flexibility to WiMAX---capabilities not before supported by broadband wireless technology.
19. Is WiMAX Technology Secure?
The short answer is yes, as never before with broadband wireless systems. However, this area appears to be early ground that vendors are staking out to differentiate their products and philosophies. The WiMAX standard itself incorporates more, better and more flexible security support by far than the Wi-Fi standard launched with. It can be sometimes confusing when industry pundits and detractors talk of standards such as WiMAX and then in the same breath describe ways in which vendors will be “different” or that WiMAX security might be weak. At first glance, these comments on the part of some vendors zealous to promote the added capabilities of their products can leave one feeling uncertain about the quality and reliability of the product.
Security is probably a good place to explain the difference between the very robust base standards of WiMAX and the ways in which individual vendors can still differentiate their products (with additional and perhaps more powerful or convenient features) beyond the features that the base standard offers. We will explain the base WiMAX security standard in the next section. However, what is important to understand is that it is quite robust. Perhaps more importantly, it allows for additional feature sets that could be added by various vendors to achieve security results as good as or better than any competing wireline broadband option even those being used for extremely secure governmental applications. Typical residential service doesn’t require the kind of security a bank, hospital or government often need. WiMAX can handle this.
An example can be helpful here. Let us say that a broadband wireless service provider chooses one particular customer premise equipment (CPE) radio that has nice features and an especially good price for its consumer based offering. These CPEs possess normal WiMAX security functionality which is at least as good as other broadband consumer technologies such as cable. It might choose to utilize a second vendor’s base station to feed service to those radios that also possesses enhanced security capabilities adding an additional security overlay to the base security of the residential network consumer purposed CPE radios---particularly in the backhaul portion of the network. This could add a small layer of additional support to radios that, while secure, could not feature enhanced capabilities due to the cost factors that consumer radio business requires.
This same base unit could also offer the company an ability to support an additional layer of radios for business or governmental or health care industry customers (where HIPPA confidentiality compliance is of great importance to us all) that actually have a DIFFERENT CPE radio that, while more expensive, possesses feature sets that take full advantage of extended security features that are commonly added to high-security government networks. It does not detract from the network for perfectly serviceable residential class security capable (and inexpensive) radios to coexist with premium feature (and cost) WiMAX products on the same network designed to serve specialty customers. Similar add one products are used with wireline products but often require additional hardware beyond the modem.
20. Does WiMAX use wired equivalent protocol (WEP) like Wi-Fi?
No. WiMAX uses much newer security protocols with enhanced encryption capabilities. Wi-Fi itself has enjoyed several security enhancements including the WPA technology and currently WPA-2. Both technologies have significantly improved security technology.
21. What is the WiMAX Security scheme/protocol?
Realizing the sticking point that security has been in the widespread adoption of broadband wireless service, the IEEE and the forum both determined to define a robust security environment. WiMAX security supports two quality encryptions standards that of the DES3 and AES, which is considered leading edge. The standard defines a dedicated security processor on board the base station for starters. There are also minimum encryption requirements for the traffic and for end to end authentication, the latter of which is adapted from the DOCSIS BPI+ security protocol.
Basically, all traffic on a WiMAX network must be encrypted using Counter Mode with Cipher Block Chaining Message Authentication Code Protocol (CCMP) which uses AES for transmission security and data integrity authentication.
The end-to-end authentication the PKM-EAP (Extensible Authentication Protocol)methodology is used which relies on the TLS standard of public key encryption.
At least one chip company designed processors to support this standard of onboard security processor.
22. What is IEEE 802.16?
The IEEE 802.16 working group is the body tasked to determine the final specifications to be included in the WiMAX specification. What this body does not do is ensure commercial compatibility with the standards. The IEEE 802.16 standard is similar but not exactly the same as the European driven HiperMAN or the Korean Wi-Bro standard.
23. How is WiMAX different from IEEE 802.16?
The WiMAX Forum is a non profit trade association industry group with a different but crucial mission from the IEEE 802.16, HiperMAN or Wi-Bro standards working groups. Those groups imperative is to formulate the technology specifications. The forum shoulders the task of incorporating the variations in the three specifications groups to ensure interoperability amongst them.
Additionally the forum regulates and defines the testing parameters for true WiMAX Certification of interoperable products. The ultimate result is that both bodies are very collaborative but with clearly delineated responsibilities.
24. Will WiMAX be a Global Standard?
Yes. WiMAX is a Global Standard that will ultimately certify products that can be sold worldwide and interoperate with gear in the same frequency range and power range. It is important to note that different countries utilize different spectrum frequencies for broadband delivery. For instance the licensed band 2.5 GHz range in the US is also widely used around the world. However, the widely used international broadband spectrum range in the 3.5 GHz channels are not available in the US. The early waves of WiMAX products are not intended to function in multiple spectrum ranges.
25. What are the benefits of a Global Standard?
The best example of the benefits of a global broadband standard can be found in the early decision by European cellular carriers to adopt the global system for mobile communications (GSM). This standard eventually caught on in many regions from Asia to the Middle East and Africa. It is in many ways the de-facto international standard for cellular service. This commonality of standard resulted in very rapid adoption of cellular wireless service as well as strong innovation and progressive product offers by carriers, ranging from using one’s cell phone to pay for vending machine products to short message service (SMS) products.
In the US the relatively fragmented technology environment with three primary competing technologies has prevented intercarrier roaming onto disparate networks. It also resulted in higher costs for service and phone products (which have to be re-configured by vendors to work on various technologies).
A global standard simplifies the equipment vendor process, reduces costs, speeds customer acceptance and adoption and encourages faster product and service innovation
26. What other major standards will WiMAX include/support?
There are three International standards that are in common acceptance or in the process of finalization. These are the IEEE 802.16, the European HiperMAN and the Korean Wi-Bro. These standards have many similarities but there are some differences. A major task of the WiMAX Forum ™ is to ensure that support for all three are incorporated into the global WiMAX standard.
27. What is Korea's WiBro?
WiBro is an acronym for wireless broadband. Korean standards makers adopted the term to describe their initiatives towards adopting a version of the 802.16e standard. Basically the Korean standard chose to accept the mobile WiMAX iteration of 802.16e, rather than any future version that included backwards compatibility to fixed wireless 802.16 systems. Korea enjoys probably the most extensive 3G deployments in the world already, and its fixed broadband access per capita is the highest in the world. What it saw it needed was an improved mobile broadband. In fact the Korean government issued the first three deployment licenses for WiBro in January of 2005. This is not Mobile WiMAX, which will likely incorporate some methodologies to support the previous 802.16-2004 fixed broadband wireless standard. Since the WiMAX Forum has chosen to interoperate with WiBro this should ultimately result in compatible systems. WiBro in many respects is driving the mobile side of WiMAX at least from the point of view of vendors eager to provide products to these early deployments.
28. What is Europe's ETSI HiperMAN?
The ETSI HiperMAN is commonly thought to be the equivalent of IEEE 802.16 (or WiMAX). In point of fact it is the European version addressing spectrum access under 11 GHz. There is a second European standard emerging called ETSI HIPERACCESS that will define (mostly licensed uses) above 11 GHz (approximately). Since the Forum has committed to supporting and incorporating the HiperMAN standards into the overall WiMAX standard, interoperability should be a constantly addressed issue. The IEEE 802.16 standard covers spectrum ranges up to about 66 GHz inclusively. Complete ETSI standards can be downloaded at: ETSI Standards.
29. What is Europe's ETSI HiperLAN?
The European Telecommunications Standards Institute (ETESI) formulates telecom standards very similarly to the US based IEEE. The HiperLAN standard was ETSI's answer to the IEEE 802.11. However, HiperLAN comes in two types The Type 1 which addresses the 2.4 GHz band and the Type 2 which covers 5 GHz frequencies. There are other variations, some administrative relating to European licensing methodologies. For more information see RTTE Directives. However, in broad terms HiperLAN and IEEE 802.11 are roughly equivalent.
WiMAX Forum
30. What is the WiMAX Forum?
The WiMAX Forum was established in mid 2001 as an industry association. The Forum describes its mandate as one to coordinate testing and ensure the certification of interoperability of WiMAX equipment to the standards of the IEEE 802.16, ETSI HiperMAN and Wi-Bro standards. The forum shoulders responsibility to promote the adoption of broadband wireless gear beyond the adoption of a technical standard by working to remove barriers to broadband wireless adoption. To this end the Forum maintains working groups formed to address specific elements including regulatory, certification, technical, marketing, service provider, networks and applications.
31. What is the Forum website?
www.wimaxforum.org
32. What company owns WiMAX?
No single company owns WiMAX. The terms WiMAX CERTIFIED and The WiMAX Forum are registered trade mark of the WiMAX Forum, which is an industry association formed to promote broadband wireless adoption and certify interoperability for members radio products.
33. Is WiMAX or the WiMAX Forum a public company?
The WiMAX Forum is a non-profit industry association formed by leading silicon providers, broadband wireless access carriers, radio vendors, integrators, consultants and media groups among others. It is not a commercial company in the sense of a corporation formed to sell specific products.
34. How many companies are in the WiMAX Forum?
The most recent count of members exceeds 310. Its members can be found at WiMAX Forum Members.
35. What does the Forum do?
Its stated mission is to remove barriers to the adoption of broadband wireless by addressing roadblocks on several fronts from regulatory (promoting the adoption of adequate spectrum inventory to governmental regulatory bodies) to certification (ensuring the interoperability of WiMAX Forum member's product lines) to marketing (promoting the technology and capabilities to the world).
36. How do you join the WiMAX Forum?
There are three levels of membership in The WiMAX Forum: Regular, Principal and Board (Invitation only). Each level offers different membership benefits, responsibilities to the group and costs associated with it. Some types of companies may only join in certain categories. Details can be found at WiMAX Forum Membership Details.
37. What kind of companies should join the WiMAX Forum?
Stakeholders in the success of broadband wireless either fixed or mobile are likely members for the Forum. Current membership includes broadband service providers, equipment vendors, silicon fabricators as well as software vendors, integrators and media that cover the WiMAX space.
38. What is a WiMAX Forum Profile?
Initially the IEEE 802.16, ETSI HiperMAN and Wi-Bro standards collectively defined technologies from 2 GHz to 60 GHz. That has since been extended to support even lower frequencies. However, broadband wireless service is not delivered in every single spectrum range in that very wide band of frequencies. The IEEE 802.16 for example supports multiple PHY layers as well as several different radio polling technologies that vendors could use. Additionally the technical rules as defined by the various controlling governmental entities throughout the US and international communities for various spectrum bands do differ, necessitating variations in the PHY layers of radios.
Ultimately this means that the Forum chose to define profiles that will support the PHY layers that member radio vendors will need based on their planned equipment offerings. Additional profiles will come online as needed. Initially this means the Forum chose to address the 256 orthogonal frequency division multiplex (OFDM) PHY with a single MAC to create a initial interoperability specification set.
39. Is Intel WiMAX? Is Intel The WiMAX Forum
Intel Corporation and The WiMAX Forum are separate entities. Intel is a major supporter of WiMAX technology. Intel is a prominent member of The WiMAX Forum along with a handful of other visionary firms. It has provided essential leadership and assistance to the Forum from its inception. Intel lends expertise, scholarship and critical support to the forum. In many ways it has also been amongst those companies most publicly supportive of WiMAX technology.
40. Why is the WiMAX Forum needed?
International broadband wireless (particularly fixed wireless) technologies are fragmented and flailing to find their place in the high-speed service landscape. The diverse, competing proprietary technologies confuse customers unsure how to parse the advantage claims of vendors. It slows adoption by carriers and creates uncertainty in customers minds as to reliability and capability.
Costs are high relative to competing broadband technologies and customer growth is relatively stagnant. This is a huge problem as broadband wireless access is perhaps the best choice to solve the data needs of many potential customers in rural and remote areas of the US or developing countries lacking the base infrastructure to support traditional wireline broadband products.
The WiMAX Forum aims to cure these ills by creating focus in the industry, consistent and improved technological capabilities and far lower costs for all.
41. Who are the leaders in WiMAX and the WiMAX Forum?
Every WiMAX Forum member contributes to the development and success of the technology. The founding members of the WiMAX Forum should be looked at as especially visionary leaders as regards the technology - certainly Intel’s name has been synonymously used with WiMAX. But a number of other firms including Fujitsu, Wi-LAN, Aperto and others contributed significant technology, expertise and leadership to the enterprise.
42. Is the WiMAX Forum and Wi-Fi Alliance the same thing?
The Wi-Fi Alliance and the Wi-MAX Forum are two completely separate bodies with varying charters. However, there are similarities. The Wi-Fi Alliance is also a non-profit standards body designed to promote the IEEE 802.11 wireless LAN technology. Its mission includes Wi-Fi CERTIFIED interoperability testing of Wi-Fi WLAN products.
The WiMAX Forum has stated that it will work with other such standards body to ensure seamless transitions to and from each group’s certified products. The Forum’s vision appears to be to encourage eventual cross-handoffs between varying broadband wireless standards to the enhancement of all parties. Such capabilities should greatly strengthen the value proposition of all broadband wireless technology in the marketplace.
Another recent WiMAX alliance body is the WiMAX Global Roaming Alliance dedicated to smoother roaming experiences between broadband wireless carriers.
43. What is the WiMAX ecosystem?
In many ways the WiMAX ecosystem is one of the most important aspects of the power of the technology. Much like the environmental ecosystem it is named for, the viability of WiMAX in general will depend on the interaction of many firms delivering different but crucial aspects of the solution to the market.
Just like a marine ecosystem has numerous plant, fish, coral and even water conditions that affect life for all, the WiMAX ecosystem consists of standards bodies, chip vendors, radio manufacturers, systems integrators, software developers, trade groups and even the media to address aspects of the technology. For WiMAX to succeed the over 300 current members of the WiMAX Forum must act in concert to develop, produce, certify, promote and deliver a quality product.
Just at the chip level, the variety of companies delivering solutions ranging from the OFDMA technology being used in Mobile WiMAX to a wide variety of system-on-a-chip silicon providers, offer the variety of support and implementation strategies that will either ensure or fail to ensure that the technology supports the range of optional features that will garner customer attention.
The various radio vendors and their most direct partners the system integrators deliver unique solutions tailored to the various market niches that offer opportunity both to them and their service provider customers. Both fulfill specific roles within the ecosystem.
The WiMAX ecosystem is a crucial element of success for this technology. The widespread quantity and quality of the companies supporting WiMAX in their various ecosystem roles is a major reason that the market place has taken the technology so seriously. It is also the industry’s greatest hope for success.
44. Are WiMAX standards finalized?
Likely, especially if the technology is a big success, WiMAX standards will never be completely finalized. Other standards such as the cable DOCSIS have continued to evolve even once a very mature level of performance was realized. However, it has evolved more slowly. WiMAX being a young standard has moved swiftly through several updates even before testing standards were defined and products began to be widely available. Its final Fixed WiMAX version standard is close to market. Firms are just awaiting product testing.
The technology has evolved from the base 802.16 standard through several updates during the last few years including:
802.16a
802.16c
And finally 802.16d or 802.16-2004
All of which are Fixed WiMAX standards primarily. This most recent standard of 802.16-2004 is in most respects completely finalized excepting that the last tweaked testing procedures to ensure interoperability have not been completely laid down. That is happening as the summer of 2005 draws to a close. The Cetecom labs and the Forum expect to begin interoperability testing with published results during the late third quarter of 2005 or fourth quarter of 2005.
Another version called 802.16e or Mobile WiMAX is due to be finalized during the middle of 2006. This version, which is not backwards compatible with the 802.16-2004 fixed standard is largely defined in terms of the mandatory elements of the standard (those largely ensuring interoperability compliance). It awaits agreement on the optional features aspects that the first product profile for 802.16e will support.
Products based on this standard are being worked on assiduously by vendors who believe that meeting the mandatory elements will leave their final products very close to certifiable status. This should jump start product availability (at least with some early gear) in late 2006 and early 2007.
45. What is IEEE 802.16?
The IEEE developed the 802.16 in its first version to address line of sight (LOS) access at spectrum ranges from 10 GHz to 66 GHz. The technology has evolved through several updates to the standard such as 802.16a, 802.16c and the current 802.16d or 802.16-2004 standard and lastly the mobile 802.16e standard. The first update added support for 2 GHz through 11 GHz spectrum with NLOS capability. Each update added additional functionality or expanded the reach of the standard.
For example the 802.16c added support for spectrum ranges both licensed and unlicensed from 2 GHz to 10 GHz. It also improved quality of service (QOS) and certain improvements in the medium access control (MAC) layer along with adding support for the HiperMAN European standard, an increased number of physical (PHY) layers and transport mediums such as IP, Ethernet and asynchronous transfer mode (ATM).
At its core the technology was intended to take a number of best of breed proprietary enhancements that had been made by vendors using the 802.11 standard and combine them together in a very marketable and standardized WiMAX product.
For example, older broadband wireless technology such as the Wi-Fi or 802.11b system utilized carrier sense multiple access (CSMA) crosstalk methods for base stations and customer premise equipment (CPE) to talk to one another. Basically, this meant that each radio was constantly talking creating inefficient overhead. It also resulted, especially at times of high traffic, in increased packet collisions and retransmissions, further exacerbating the problem. Some of the proprietary MAC systems built later utilized the base station to define when CPE would be polled in order to eliminate this problem. In the way of a permanent cure the 802.16 protocol supports multiple methods of polling that a vendor can choose to use. Some of these include piggybacking polling requests within overhead traffic, groups polling or dynamic co-opting of bandwidth from another unit by the CPE. The key is that the radios will be interchangeable based on the Forum’s initial product profile as well as more efficient.
46. What is IEEE 802.16d?
The current version of 802.16 Fixed WiMAX that supersedes previous standards is 802.16d or as it is sometimes called 802.16-2004. Its product profile utilizes the OFDM 256-FFT system profile, which is just different enough from its sister standard of Mobile WiMAX (802.16e) that the two appear to be incompatible. Interestingly, both standards support both protocols within the technology protocol as well as the one chosen for Mobile WiMAX and the Korean WiBro standard. If the Forum had elected to use an OFDMA version in Fixed WiMAX, it would have been far easier to provide an upgrade path.
This particular jarring change likely points to the emerging understanding of the marketplace power of WiMAX. It especially indicates the power of the Korean WiBro influence, which heavily influenced the use of OFDMA in the Mobile Standard.
The Fixed WiMAX 802.16-2004 standard supports both time division duplex (TDD) and frequency division duplex (FDD) services---the latter of which delivers full duplex transmission on the same signal if desired.
47. What is IEEE 802.16e?
The true Mobile WiMAX standard of 802.16e is divergent from Fixed WiMAX. It appears to attract a significant number of Forum members to the opportunity to substantively challenge existing 3G technology purveyors. While clearly based on the same OFDM base technology adopted in 802.16-2004, the 802.16e version is designed to deliver service across many more sub-channels than the OFDM 256-FFT. It is important to note that both standards support single carrier, OFDM 256-FFT and at least OFDMA 1K-FFT. The 802.16e standard adds OFDMA 2K-FFT, 512-FFT and 128-FFT capability. Sub-channelization facilitates access at varying distance by providing operators the capability to dynamically reduce the number of channels while increasing the gain of signal to each channel to reach customers farther away. Each subscriber is linked to a number of subchannels that obviate multi-path interference. The upshot is that cells should be much less sensitive to overload and cell size shrinkage during load than before. Ideally customers at any range should receive solid QOS without drops that 3G technology may experience.
The 802.16e standard will most likely be utilized primarily in licensed spectrum for pure mobile applications.
Will the Fixed WiMAX standard be supplanted in time by the “so described” more robust 802.16e to re-connect the two? That is a question likely to be answered by market forces.
WiMAX Equipment
48. What companies are involved with WiMAX (link to Forum list)?
As of last count the WiMAX Forum membership exceeded 310 companies with many other firms evaluating the technology as a possible fit for their business and technical models. A complete list of WiMAX Forum members can be found on its site. WiMAX Forum Members.
49. What are the benefits of WiMAX certified equipment to service providers?
The benefit of a consistent technological standard alone to the service provider community is significant. The collection of numerous best of breed technology innovations into one consistent package will improve service. The WiMAX spectrum efficiency gains are very solid, which will leverage the ability to provide service to more dense customer bases for lower costs. Also, a more consistent technological approach is a key ingredient to identifying best practices for delivering broadband wireless access consistently across multiple geographic and radio frequency (RF) environments.
The cost savings from silicon chip based support of WiMAX technology offers profound implications. The WiMAX forum states that it expects the first wave of customer premise equipment (CPE) to be available to carriers in the $350 US price range. Second generation gear which will offer improved self-installation capabilities (per the Forum) should sell in the $250 US cost range. Whereas the third generation of WiMAX gear usable for laptops and other portables could sell in the $100 range.
Industry pundits widely believe that sub $100 CPE is essential for the broad acceptance of BWA technology. Lastly, the opportunity to shop vendors for enhanced feature sets while being able to consistently count upon a base set of radio capabilities can only help the service provider industry in creating market differentiation from wireline products---hopefully heralding a new era of enormously flexible, mobile and powerful broadband services.
50. Are WiMAX radios available now?
WiMAX CERTIFIED radios are not yet available. A number of radio vendors have announced WiMAX Compliant products that adhere to the strictures of IEEE 802.16 (so-called precursor WiMAX products). However, none as yet have been tested for true interoperability. Initial interoperability testing by the Forum should begin during the second half of 2005 and continue on an ongoing basis. Early estimates for WiMAX CERTIFIED gear availability range from the end of 2005 to the first half of 2006 depending on the manufacturer in question.
51. What is precursor WiMAX Gear?
So called precursor WiMAX radios are broadband wireless products (mostly developed by WiMAX Forum members---but not all) that submit to the IEEE 802.16 technical standard. These radios are claimed to mount the full functionality of the IEEE 802.16 standards base. However, they have not yet been physically tested for interoperability in field deployments. It is important to note that the technical capability of these radios is often very high and can deliver high quality broadband wireless access for users. For a variety of business case reasons waiting for certified products to be available is considered a strategic mistake by some analysts. The opportunity to secure a broadband customer now and later defend that customer (perhaps with WiMAX upgrades) against competition is much more appealing than waiting for more competitive products to try to wrest that consumer away from the provider who initially seized the business.
52. Will precursor WiMAX radios interoperate with true WiMAX certified radios?
That has yet to be determined for any radio vendor. Physical certification testing is required to assure interoperability. Likely this will vary from vendor to vendor. WiMAX Forum members assert that their products hold the inside track to successful WiMAX CERTIFICATION. Several vendors have asserted that their precursor gear will be backwards compatible with future WiMAX CERTIFIED gear. This is a crucial step that will pave the way for commercial deployments in 2006. It should be noted that the IEEE 802.16e (or Mobile WiMAX specification set) has not been completely formulated. Products supporting that technology are likely at least years away.
53. Which companies are currently manufacturing precursor WiMAX radios?
Literally dozens of firms have announced pre-WiMAX or precursor WiMAX products. Many of these are WiMAX Forum Members.
54. When will WiMAX Forum certified equipment be available?
The timetable for WiMAX CERTIFIED gear has morphed a bit as chip vendors and radio manufacturers adjusted to the requirements of essentially building a new cohesive industry from scratch. There has been some criticism of the timeline for actual commercial WiMAX launches to begin. However, it is important to understand that the broadband wireless access industry has possessed no true outdoor MAN level standard of any kind in the past. The industry's customer demand notwithstanding, this limitation has been very strong.
Essentially regardless of when WiMAX CERTIFIED gear becomes available is in many ways a moot point. There are no other standard options extant that could meet future BWA industry needs. The BWA industry needs WiMAX as soon as it becomes available whether that be near term or far term. Happily however, it appears that 2005 is the year that interoperability testing will reach full swing with at least some products coming online no later than the first half of 2006.
55. When will the WiMAX Forum begin certifying equipment?
The Forum's set date for interoperability testing was set for June 2005.
56. Where will the equipment be tested?
Malaga, Spain-based Cetecom labs was selected to provide testing for WiMAX product interoperability. The firm has a commercial office in Madrid. The selection process took over a year to choose a winner and hinged on a number of factors including the presence of regional Cetecom labs that WiMAX vendors the world over could easily access. Additionally Cetecom possessed a strong track record of experience with standards such as: GSM/GPRS, EDGE, W-CDMA, WiFI and Bluetooth. The lab will function as an independent testing group to confirm compliance with IEEE 802.16, ETSI HiperMAN and the recently added Wi-Bro standard, along with product interoperability utilizing the specifications set by the WiMAX Forum to determine testing requirements.
57. Which companies will be manufacturing WiMAX products for service providers and end-users?
This list is extremely long and will only grow larger. A good place to start looking for firms that will produce this equipment is at the WiMAX Forum Members list.
58. How will WiMAX Forum Certified products benefit enterprises? Residential users?
The existence of a cost-effective, modern leading edge alternative to the traditional wireline broadband products most commonly used in the US and International communities today will foster competition---resulting in lowered prices and enhanced services for all consumers. Widespread adoption of WiMAX can adroitly accomplish this goal.
Rural areas seeking economic development through the recruitment of industry will gain an important tool to attract enterprise customers to more remote areas. Internationally countries with only modest broadband penetration could achieve rapid broadband penetration by utilizing WiMAX systems.
WiMax promises to help close the gap in areas where traditional broadband has not been economically viable and residents have suffered with inferior Internet connectivity.
59. What does WiMAX Forum Certified mean?
The distinction between a WiMAX compliant product and a true WiMAX CERTIFIED radio solution is a crucial one. The WiMAX Forum is the only body empowered by its members to formulate and monitor interoperability testing. Radios that are stamped as WiMAX Forum Certified provide carriers and consumers peace of mind that products meet the IEEE 802.16 standard and that each vendors gear has been physically tested and certified to work with other certified radio products. This is essential to widespread adoption of the technology.
60. How is this different from WiMAX Compliant?
Any company could build WiMAX compliant radios from the technical specification standpoint. However, that does not mean those radios would work with other vendors gear. It is one thing to build a radio that meets a technical specification and quite another to ensure that vendor products (built with varying engineering methodologies and manufacturing processes) actually work together well in the real world. WiMAX CERTIFIED is the only stamp of approval for such gear.
WiMAX Service & Applications
61. Should ISPs wait until WiMAX certified gear is available before offering service?
A compelling business case can be made, that considering the very high estimates of broadband subscriber growth over the next few years, any delay in launching a well-thought-out broadband wireless operation could blunt opportunities for carriers. There is no doubt that as the percentage of potential broadband subscribers served moves closer to the total size of the available pool of such subscribers that customer acquisition growth rates will slow.
62. What are the advantages of deploying now with precursor gear over waiting for WiMAX Certified products?
Existing business wisdom in many industries is that it is usually easier and far cheaper to defend a customer previously won from new competition entering a company’s market, than to attempt to persuade a customer already being well served by other broadband competitors. Also, due to the incredibly flexible nature of broadband wireless technology, upgrades to new gear can be made affordably and very fast relative to other infrastructure broadband technologies. This tends to reinforce the view that the battle to convince customers is more important than waiting for having the most cost effective, technically innovative products to offer them. This is probably the strongest argument for launching with precursor gear.
It is worth noting that highly disruptive technologies can implode this argument. However, WiMAX is composed of mostly existing and proven technology repackaged in a more consistent and compelling standard. It seems most likely that adding WiMAX to the mix, once available, will only accelerate wireless carrier’s build-out rates as costs drop. It should also increase margin for those customers already being served.
63. Are there downsides to deploying now with precursor gear?
There are definite downsides risks to deploying immediately with precursor gear. However, they appear manageable.
Some risks include the possibility that the precursor gear selected won’t be seamlessly interoperable with new WiMAX gear. This is a downside consideration but perhaps the most manageable. WiMAX and other precursor WiMAX gear can be bridged with a simple Ethernet link and then simply expanding the next site as a WiMAX site while the company continues to operate and expand the existing precursor network as before. Upgrades to WiMAX could then be made in the precursor sites as economic factors dictate.
Some precursor gear may have slightly lower performance characteristics. Most vendors precursor gear should carry virtually identical functionality to WiMAX CERTIFIED products, rendering this a very low-level risk.
Precursor radios could potentially be more expensive. This is probably the least likely scenario as radio costs even without WiMAX have dropped steadily over recent years.
Downside risks are very minimal for deploying now.
64. When will I see WiMAX Broadband in my area?
The first certified interoperable WiMAX radios are pending Certification testing later this year. However, some companies have launched precursor WiMAX radios, primarily in the International standard spectrum of 3.5 GHz already. Some of those firms are guaranteeing interoperability once certification tests are completed. Customers in countries utilizing this spectrum may have already started to see WiMAX broadband. However, for most of the US, WiMAX CERTIFIED interoperable gear will not likely appear until 2006.
It is important to note that since much of the WiMAX functionality has been available for some time, that many customers already receiving broadband wireless service in the US and abroad, may in fact be already enjoying WiMAX quality or near WiMAX quality service.
65. When will WiMAX Mobile be available?
Mobile WiMAX or IEEE 802.16e technical specifications are still in the process of being finalized. Best estimates in the industry is that Mobile WiMAX products are at least two years away from any type of commercial deployment.
66. Can WiMAX handle Video?
Yes. WiMAX is designed to support high quality video as a basic aspect of the technology.
67. Will WiMAX be sold through retail stores?
Eventually yes. They will be as widely available as DSL or cable modems. However, in the near term, carriers will deliver and install radios themselves for a variety of reasons. WiMAX heralds an era of faster and easier installation especially for ISPs delivering service in licensed bands that support greater NLOS performance. But for the foreseeable future broadband wireless networks are not widely built out. This means it will take time for coverage to became more universal even or especially with Mobile WiMAX. The industry also requires more (probably licensed) spectrum available for carriers for optimum service capabilities and coverage. Widespread coverage will enable the public to eventually provision radios
