Techno-Economics of Mobile WiMAX

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Jari Nieminen Jari.nieminen@tkk.fi

23.3.2007

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Table of Contents

1. Introduction to Techno-Economics 1.1. Introduction 1.2. Techno-Economic Tools 1.3. Risk and Sensitivity Analysis

2. Fixed and Mobile WiMAX 2.1. WiMAX in a Nutshell 2.2. Technical Aspects 2.3. Mobile WiMAX 2.4. Chapter Summary

3. Market Situation 3.1. Competitors 3.2. Services 3.3. Business Cases 3.4. Chapter Summary

4. Economical Aspects of Mobile WiMAX 4.1. Initial Investments 4.2. Operating Costs 4.3. Sensitivity Analysis 4.4. Chapter Summary

5. Conclusions and Summary

6. List of References

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1.1. Introduction

The purpose of the Techno-Economic analysis is to find out how profitable new

technology may be and what kinds of risks are involved. This analysis consists of

different aspects of the new technology; it takes into account for example

competitors, possible services, markets, initial investments and operating costs. So

this analysis can be very accurate but we have to remember that there has to be done

some presumptions. In order to determine which parameters are critical for each

technology, we need to carry out the sensitivity analysis, where we are trying to

estimate how the variations of different parameters affect the profitability of certain

business case.

Techno-economics is often future oriented and it can be used to forecast which

technologies will be dominant. By using different scenarios, (scenarios are plans or

projections on circumstances [Rii06]), we may study in which circumstances the new

technology will be profitable and where it is not. These scenarios can include

different amount of users, population density, competing technologies, pricing,

environment etc. In this paper the competing technologies to Mobile WiMAX will be

3G and WLAN. The different scenarios will be presented and the assumptions and the

information behind the conclusions. Also systematic analysis is required to recognize

new opportunities and threats.

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1.2. Techno-Economic Tools

Techno-Economic methods use different tools in order to estimate how new

technologies are adapted and what is the effect of them to existing technologies.

These models also need to consider which are the economical aspects and market

related parameters and assumptions. Karjalainen [Kar06] presented different

economical tools for evaluating profitability.

Discounted Cash Flow (DCF) – analysis shows what is the value of a cash flow

adjusted for the time value of money. From this analysis the payback period can be

seen, which means the amount of time required before the cumulative cash flows

turns positive. Another important value from this analysis is the Net Present Value

(NPV), which is sum of all DCFs during a given period.

Because this analysis is usually done to new technologies, different forecasting

methods are important. Smura [Smu06] shows the most important forecasting

methods. From these methods the most popular ones are Expert opinion, Trend

analysis and Monitoring. By combining different methods it is possible to get better

results and usually three methods is considered adequate in order to get reliable

results.

When performing economic analysis for a technology, the both sides of the cash flow

need to be considered. From the revenue side we need to consider what the

penetration will be, how market share evolves and how the tariffs will develop. Also

some minor revenues can come from for example interconnections and roaming.

When looking at the cost side modeling, there are two main things to take into

account: CAPEX and OPEX. CAPEX stands for capitalized expenses generally

arising from the initial costs of a new technology i.e. infrastructure. On the other

hand, OPEX in accounting means expensed costs which have effect on the current

year only. This consists of different operational and maintenance costs.

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1.3. Risk and Sensitivity Analysis

When making decisions about launching new technologies it is very important to

know what kind of risks you’re taking. To cope with the uncertainties, analysis needs

to be done to find out the possible risks. Schmidt [Sch02] presents the fundamentals

of business cases and managing risks. Smura also considers this problem from a more

technical viewpoint in [Smu06].

In sensitivity analysis the main point is to find out how changing of some parameters

affects the whole picture. There might be some variance for example in component

prices, service penetrations and tariffs. When changing these different parameters, we

can see how they affect our business plan. Some critical variables can exist, and also

some which don’t have any significant meaning. This sensitivity analysis is tightly

related to the risk analysis as well.

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2.1. WiMAX in A Nutshell

WiMAX or Worldwide Inter-operability for Microwave Access is an organization

which takes care of the standardization of a common specification of the IEEE 802.16

standard. The basic idea behind this WiMAX is to offer broadband services over the

radio link for worlds rural and developing areas where broadband is currently

unavailable. The standard IEEE 802.16-2004 [IEE04] defines this wireless data

access protocol. An amendment has also been published for this standard known as

802.16e-2005 [IEE06], whose main task is to introduce mobility to WiMAX.

WiMAX was created to address a serious issue common in many wireless devices,

which is Quality-of-Service (QoS). In wireless systems QoS includes for example

rate, delay, latency and mobility. WiMAX uses Orthogonal Frequency Division

Multiplexing (OFDM), which has been widely accepted as the next generation

wireless standard for providing wideband communications in rural areas. From

[Hus06] can be found more about OFDM systems in general.

The main advantages of Mobile WiMAX are fixed, nomadic, portable mobile

connectivity at vehicular speeds. Also the tolerance to multi-path and self-

interference by using OFDMA are important advantages.

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2.2. Technical Aspects

From the technical point of view, WiMAX includes several advances compared to the

older wireless systems. The use of adaptive modulation and coding in WiMAX

allows higher connection speeds close to the Base Station (BS) and lower speeds

when the quality of the radio channel reduces. So for home and business users

WiMAX can provide high data rates, and for dense areas QoS with moderate

connection speeds. Alternatively it is however possible to offer good QoS on rural

areas at the expense of data rate. As a backhaul technology, WiMAX makes it

possible for different LANs to interconnect through a WMAN as well. [Hus06]

WiMAX standard provides optional features and a signaling structure that enables the

usage of intelligent antenna systems, specifically called adaptive antenna systems.

This is made possible with the feedback from the Subscriber Station (SS) to the BS.

Also it is possible to increase data rates and diversity by using Space Time Block

Codes (STBC) so the receiver performs maximum likelihood (ML) estimation of the

transmitted signal based on the received signal. This is also an optional feature.

Mobile WiMAX also supports beam forming and Multiple-Input Multiple-Output

(MIMO) Systems.

In WiMAX the adaptive modulation and coding makes it possible to adjust the data

rate depending on the quality of the radio channel. The changing radio channel

conditions are of course the same for every wireless system. But in WiMAX, the fast

feedback method allows better approximations of the channel and so enables faster

adaptation to the channel conditions. [IEE04] also specifies possible configurations

for using frequency reuse factor 1, which means that in every cell the same frequency

band can be used. Both of these methods lead to better usage of the scarce radio

resources.

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The [IEE04] specifies the usage of the bandwidth 2 - 11 GHz and the [IEE06]

specifies the bandwidth below 6 GHz. The former standard 802.16 was specified for

the whole bandwidth 2 – 66 GHz. In general three frequency bands for WiMAX are

considered: 2,5 GHz (licensed), 3,5 GHz (licensed) and 5,8 GHz (unlicensed).

2.3. Mobile WiMAX

Mobile WiMAX is introduced in [IEE06] standard. This standard is based on the

fixed WiMAX standard, [IEE04]. This [IEE06] standard is specified as “Air Interface

for Fixed and Mobile Broadband Wireless Access Systems” and it is made to specify

the mobility in WiMAX. At the moment there doesn’t yet exist any devices to

conform with this standard. Even though there are devices conforming to [IEE04],

there are still many parts of the standard which have been left out. [MVa06]

This [IEE06] standard specifies mobility related issues concerning WiMAX, for

example Macro Diversity Handover and Fast BS Switching. These specifications are

very important if we want to utilize the full potential of WiMAX. Also this

amendment makes it possible to achieve inter-cell mobility, basically up to 120 km/h.

The original standard doesn’t support any kind of mobility and its performance is

degraded heavily if the SS is moving.

In Mobile WiMAX it is also possible to use Scalable-OFDMA (Orthogonal

Frequency Division Multiple Access) which means that the used channel bandwidth

is scalable. The use of OFDMA gives many advantages compared to OFDM, for

example better coverage and better channel availability. It also allows the use of

simpler and cheaper Power Amplifiers and makes it possible to assign multiple users

to TDD (Time Division Duplexing) same time slot.

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2.4. Chapter Summary

In this chapter the WiMAX and standards related to it were presented in general.

Technical aspects and the differences between Fixed and Mobile WiMAX were also

introduced. This introduction was done briefly because the focus of this work is on

the economical side of WiMAX. The standardization of WiMAX is still partly

incomplete and nowadays it contains some inconsistencies. The standardization

bodies are already planning updates to these standards, for example IEEE 802.16g

standard for procedures and interfaces for management of 802.16 devices, should be

published in the second quarter of this year. [Hre06]

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In [Hre06] the market situation of mobile markets was presented. It stated that in

mobile voice and data markets the competition is generally increasing. This is mainly

because of the many competing companies, technologies and manufacturers. This

means that the prices and margins will continue to fall. The customers agree that at

the moment cheap voice calls is the most important factor in choosing a mobile

service.

3.1. Competition

The lifecycle of a new technology can be predicted by looking back how the previous

technologies have performed. For WiMAX, the main competitors in wireless

technologies are WLAN, 3G and also HSDPA can be considered as one in the future.

In wired technologies there is of course ADSL but it won’t be taken into account here

in order to keep this study reasonable. These systems offering “last mile” – wireless

connections for voice and data have big markets in the future. The main advantage of

these wireless technologies is naturally that there is no need for dragging a cable to

the user’s house but instead the data can be sent over the air.

WiMAX and WLAN both use OFDM for signal multiplexing and the potential

achievable data rates are higher than in 3G or HSDPA. But the main difference

between WiMAX and WLAN is the mobility and coverage. WLAN is designed to

give high data rates for smaller coverage areas and it doesn’t support mobility very

well. WiMAX on the other hand can be used to offer broadband services in rural

areas because of the larger cell size. WLAN is more useful when offering fast

wireless connection in urban areas or smaller areas, for example campus.

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So WLAN can offer higher data rates than WiMAX but it has another advantage as

well. WLAN has been commercially available for several years but Fixed WiMAX

has just been released. This of course is important because every new technology will

develop in its early stages. There haven’t been any releases yet of Mobile WiMAX so

the mobility advantage compared to WLAN is insignificant. And also Mobile

WiMAX will probably face some interoperability problems at first. The price

advantage will probably be on WLANs side as well because it has been available for

customers for such a long time.

When comparing 3G and WiMAX systems, the main difference is the achievable data

rate. WiMAX potential lies in its ability to provide broadband service because 3G

systems are very slow compared to the WiMAX. But the implementation of HSDPA

will mitigate this gap between these technologies. Of course now the 3G network

covers much more than WiMAX but it has been designed for voice and moderate

packet data transmissions.

The definite advantage of 3G is the mobility but when launching Mobile WiMAX, it

will be seen how well it can perform compared to the mobility of 3G. The

infrastructure of the 3G networks already exists so there won’t be any need for new

infrastructure, updating the old ones is enough when moving towards HSDPA. In the

Table 3.1 the technical differences between 2G, 3G, HDSPA and WiMAX are

presented. From [Hre06] slide 27 more technically detailed comparison of different

wireless technologies can be found.

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3rd International CICT ConferenceLyngby, Denmark, 30 Nov – 1 Dec 2006 / J.Harno, Nokia Research Center

Network architectures� Radio network dimensioning:

0.40 / 0.60 /1.10 (not impl.)/ 3.00 (not impl.)10Mbps10MHz3400Mobile

WiMAX

0.57 / 0.89 / 2.11 / 6.36 (not implemented)4Mbps

5MHz(2 channelsper sector)

1900/2100HSDPA

0.57 / 0.89 /2.11 / 6.36

96 calls /800kbps

5MHz(2 channelsper sector)

1900/2100WCDMA

0.73 / 2.51 / 3.21 / 6.36256kbps200kHz900/1800EDGE

0.73 / 2.51 / 3.21 / 6.3670.4kbps200kHz900/1800GPRS

0.73 / 2.51 / 3.21 / 6.366.4 calls200kHz900/1800GSM

Cell range*(km)(Dense/Urban/Suburb./Rural)

Throughputper channel

Channelbandwidth

Freq. band (MHz)Technology

Table 3.1 Technical differences between 2G, 3G, HSDPA and WiMAX [Har06]

3.2. Services

As the WiMAX continues to gain attraction around the world, the carriers are looking

how to take full advantage of this cost-effective and efficient technology to provide

different services to customers. For carriers, the goal is to deliver these services as

profitably as possible which means efficient utilization of their spectrum, wide array

of services and being innovative. Most of today’s popular services require fast

internet connection and are very bandwidth and delay sensitive. Offering these

services wireless is a crucial advantage in today’s competitive markets.

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It is possible to dynamically optimize WiMAX because it supports 4 different service

classes. The Service classes are only identities for a specific set of QoS parameters.

These classes are presented in Table 3.2.

Service Type Description

Unsolicited Grant

Service (UGS)

Designed to support real time data services with fixed size data

packets sent periodically (VoIP)

Real-Time Polling

Service (rtPS)

Designed to support real time data streams consisting of variable

sized data packets sent periodically (MPEG)

Non-Real-Time

Polling Service

(nrtPS)

Designed to support delay tolerant data streams consisting of variable

sized data packets for which a minimum data rate is required (FTP)

Best Effort (BE) Designed to support data streams which no minimum service level is

required

Table 3.2 WiMAX Service Classes [Wes05]

The WiMAX standard has been developed to address a wide range of applications.

The full table can be found from [Wes05]. For requiring real time traffic three

different applications are considered: Interactive gaming, VoIP and Video conference

and Streaming media. From these VoIP requires the least bandwidth and Streaming

movies requires the most. Specified applications which don’t need real time traffic

are Information technology and Media content download.

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Now the most interesting question is how well WiMAX can perform with these QoS

demands, especially when implementing mobility to the system. This of course is not

a problem if the data rates are always high enough and latencies tolerable but always

when transmitting over the radio link there is some uncertainty. As a conclusion

Mobile WiMAX has the ability to manage these service demands and offer customers

good wireless “last mile” – connections.

3.3. Business Cases

There are different business cases when considering Mobile WiMAX depending on

what is the starting point of the company. The business cases can be divided into four

broad categories: Fixed and Mobile operators, Mobile only operator, Fixed operator

and new entrant. These starting points give different options for companies, for

example for new entrant WiMAX will the main technology but for someone else it

may be just a complementary system. Also it is possible to divide business cases to

network or service operators.

In [Hre06] the analysis is done from the first point of view and the results show that

the payback period varies between from 5,5 to 7 years for different cases. But when

looking at the Net Present Value (NPV) the divergence is much larger, from 2,3 to 20

(Mio Euro). These calculations have been made considering 8 years study period, so

these numbers are after 8 years from the implementation. And the differences in

Internal Rate of Return (IRR) are in per cent from 12% to 32%. So from this study the

business case seems to be “mobile only” GSM/EDGE operator using Mobile

WiMAX as 3G substitute.

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Different aspect was taken in [Har06] where the comparing was done by dividing

operators as network or service operator. For network operators OPEX consists of:

Site rental and electricity (27%), Leased line costs (24%), Support system (9%),

Operation & Maintenance (21%) and Employee costs (19%). For service operators

situation is different, their OPEX consists mainly of charges paid to network

operators and in addition to that end-user support and sales & marketing. After this

seven year study period the service operator has OPEX is 19,6 B€ and NPV is 4,40

B€ and for the network operator OPEX is 4,40 B€, CAPEX 0,92 B€ and NPV of 0,33

B€. So this study indicates that Mobile WiMAX is clearly more profitable for the

service operators than for the network operators.

3.4. Chapter Summary

In this chapter the main competitors were introduced and compared to the Mobile

WiMAX. As a result we can see that Mobile WiMAX has some advantages but there

are some drawbacks as well. This of course depends on which rival technology it is

compared. The services and applications point of view was also considered and how

their demands could be fulfilled, at least in theory. Finally, different business cases

were introduced. Mobile WiMAX has to be considered from different economical

aspects and here two different studies were presented. These studies show that there is

a good possibility to make Mobile WiMAX profitable but it is too early to say which

business case will be the best.

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Expenses of Mobile WiMAX consist of two parts. At first there is a need to invest

into infrastructure for building the network, these are the initial costs. After setting up

the network there are operational and maintenance costs as long as the network is

running. In this part we are considering only the network operators side so only the

costs relating to the network are considered.

4.1. Infrastructure Costs

In Mobile WiMAX the infrastructure will basically be the same as with Fixed

WiMAX. The infrastructure costs are considered as CAPEX expenses. The major

investments in WiMAX include the costs of the Base Stations (BS), Transmission

links (Point-to-Point) and Customer Premise Equipment (CPE).

We have to remember that in WiMAX CPEs are too expensive, at least at the

moment, to be fully paid by the end users. So this is the reason why those are

included into infrastructure costs. In studies, it is assumed that CPEs should be owned

by the network operator and leased out to the end users. For the transmission network

part it is usually assumed that the connections between the BSs and the core network

to be built with point-to-point radio links owned by the WiMAX network operator.

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4.2. Operating Costs

Operational and maintenance costs are the expenses included in OPEX. These costs

consist of maintenance and administration of network elements, the leasing of

equipment and antenna sites and the installation costs of BSs and CPEs. An important

part of these costs is also the installation of outdoor CPEs, as a technician is required

to visit each customer. In Table 4.1 the assumed infrastructure and operating costs are

presented.

Cost Component Price in 2006 Price evolution Spectrum license fee 25 000 € - WiMAX 3,5 GHz BS 10 000 € -15% per year WiMAX 3,5 GHz BS Sector 7 000 € -15% per year BS installation cost 5 000 € per BS + 500 € per sector - BS site rental 1 800 € per BS per year

+ 1 200 € per sector per year -

Transmission link equipment

25 000 € per BS -10% per year

P2P radio link site rental 2 400 € per BS per year - WiMAX 3,5 GHz indoor CPE

300 € -20% per year

WiMAX 3,5 GHz outdoor CPE

400 € -20% per year

Outdoor CPE installation cost

100 € per installation -

Network equipment administration and maintenance costs

20% of cumulative investments

-

Table 4.1 CAPEX and OPEX assumptions for Fixed WiMAX network deployments [Smu06]

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Table 4.1 gives some kind of idea what are the costs of the network in WiMAX.

Mobile WiMAX infrastructure is basically same as in Fixed WiMAX. The cell size of

the Mobile WiMAX will probably be smaller which would lead to an increasing of

number of the base stations. The CPEs’ and BSs’ updates might also require some

investments but not very significant presumably. These would intuitively be the only

differences between the costs of these systems. There is not yet any Mobile WiMAX

equipment on the market, so it wasn’t possible to do any accurate comparison. Also

the use of Advanced Antenna Systems (AAS) and MIMO will probably bring some

extra costs to CPEs and BSs as well.

4.3. Sensitivity Analysis

The purpose of the sensitivity analysis is to find out how different things affect to the

profitability of a certain technology. In Mobile WiMAX the larger scale commercial

roll-out will take some years. So there exist many uncertain values which affect to the

results of different business cases. Anyway we can assume that for almost every

business case the uncertainties affect in a similar way. The infrastructure costs will be

quite similar for every business case but the running costs depend on the considered

business case. This is because the user penetration will affect the running costs quite

much and for different business cases it has different effects.

The selected cell size will have significant consequences when examining the

profitability of a certain business case. It seems that the cell radius of 800 meters has

the best attributes for Mobile WiMAX and growing it does not improve the

performance. This result has been found out to be equivalent for every business case

Anyway the all business cases are feasible and having about 5 year payback period

which is typical for a new telecommunication technology. [Hre06]

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It is too early to estimate how big the role of Mobile WiMAX will be in the

telecommunications market. The markets are developing rapidly and by the time of

launching the Mobile WiMAX there might be some new technology as a competitor.

When considering the sensitivity analysis one needs to remember that at the moment

the interoperability between different vendors’ products is unsatisfactory. So we can’t

estimate how much this will affect to different vendors’ product costs. Also a critical

point of this sensitivity analysis is the price of CPEs and who will pay for those. Now

it seems that at least part of this cost will be paid by the network operator because the

price is too high for individual subscriber.

4.4. Chapter Summary

In this chapter the expenses of Mobile WiMAX were considered. Both infrastructure

and running costs will probably be quite close to the Fixed WiMAX case. Even

though the mobility will presumably decrease the capacity and that would cause more

costs to the Mobile WiMAX case. Also some considerations about sensitivity analysis

were made but it is too early to give any specific figures.

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The overview of the mobile market at the moment is that because of the increasing

and tougher competition, the prices and margins are falling. But still it seems that the

Mobile WiMAX has potential and there is active demand for it. It needs to be

carefully considered how this new technology should be used and now it seems that it

would be most profitable when complementing 3G. And for the rural areas it could be

the main “last mile” – broadband connection. Also there exist various other

possibilities, for example military or naval solutions.

Finally, I have aggregated the results to a SWOT – analysis (Strengths, Weaknesses,

Opportunities and Threats). From the Table 5.1 one can clearly see what the situation

with Mobile WiMAX is at the moment and what kind of threats and opportunities it

may be facing in the future.

Figure 5.1 SWOT – analysis of Mobile WiMAX

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First of all, as a strength offering of the “last mile” – broadband connections to rural

areas is same as for Fixed WiMAX. I have counted this also to as an opportunity

because I think there are big markets for WiMAX without that much of a

competition. Also the cell size compared to WLAN is definitely an advantage

because WLAN has been developed only to serve buildings or small campus areas.

But when comparing to 3G this advantage doesn’t exist, and we have to remember

that HSDPA will have good data rates as well.

From the mobility point of view, there will not be as good mobility as in mobile

phone networks but the mobility should definitely be better than in WLAN. On the

other hand this can be a risk if the mobility for some reason fails or doesn’t work as

well as supposed. Also the prices of the user equipment might be a problem for

Mobile WiMAX because other technologies have already their products on the

market and those will only get cheaper. The launching of Mobile WiMAX will

hopefully be soon so the time won’t be a threat. And I think that it should be launched

as soon as possible in order to be able to work with the interoperability questions. The

interoperability issues do not concern 3G and WLAN because those technologies are

already working well. Also we have to remember that the WiMAX network is not yet

comprehensive and will require funds as well.

As a conclusion can be said that Mobile WiMAX is an emerging technology which

has several advantages and it should complement the telecommunication market very

well. There are some risks and threats related to this technology but that has been the

situation for other technologies as well. It seems that Mobile WiMAX will be a

profitable business case for service operators and also suitable for network operators

but with smaller profits. And the studies show that the best business case for network

operators would be to use Mobile WiMAX as a complementary technology to 3G.

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66.. LL iisstt ooff RReeffeerr eenncceess

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Access with WiMAX/802.16: Current Preformance Benchmarks and Future Potential, IEEE Communications Magazine, February 2005.

[IEE04] IEEE std 802.16-2004: Air Interface for Fixed Broadband Wireless Access System, The

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