WIRELESS BROADBAND NETWORK

WIMAX AND 3G

Showing newest 22 of 62 posts from 02/01/2008 - 03/01/2008. Show older posts

Showing newest 22 of 62 posts from 02/01/2008 - 03/01/2008. Show older posts

W I M A X T R A N S M I T P O W E R C A L C U L A T I O N

Do we need to consider return loss of the device along with insertion loss

when we calculate the output power of the particular device?

For example Balun has return loss of 12dB and IL of 2.5 dB, when i give input

to the balun as 0dBm what will be the out put of the balun power available?

output power= Input power-IL or

output power= Input power-(IL+RL)?

In such case if the input to the BALUN is 0dBm then the output of the Balun

will be -15dBm because of the return loss 12 dB and insertion loss 2.6dB, Is

this calculation correct?

If there is really a 12 dB return loss in the balun then the calculation is

correct.

Iam just wondering why the RL of the Balun is 12dB. I think it is quite large.

We use balun to match impedance and minimize RL.

Can you tell how the value of RL obtained?

Do not consider the return loss when making your link budget or EIRP

calculations. The insersion loss is to be considered (only).

The return loss is the indicator of the health of your cable and antenna

together. The antenna is an impedence matching device from the cable (50

ohms) to free space (377 ohms) and is frequency dependant.

Since there is no perfect impedence match there will be some reflected

power. A return loss of 13 db means that 1/20 th of the power was reflected.

If you were transmitting 10 watts than .5 watts was refected. This number is

too little to worry about.

However, if you see reflected power start to rise you must ceck your cable

and antenna and jumpers.

i over looked return loss as loss due to return instead of loss of the return.

thats why i think its value is high for a loss.

to consider it theoretically in your calculation. just subtract the linear value

of RL form 1 then convert it back to dB

for 12dB RL means 1/16 of incident is reflected hence 15/16 is for the load

(1-1/16)

So your loss due to return is 10log(15/16)= - 0.28dB

[get this widget]

Read More...

I M P O R T A N C E O F T H E T R A N S M I T T I G A N T E N N A G A I N F O R T H E

B A S E S T A T I O N

As per my RF design i am getting +40dBm Tx power at the antenna port

after subctracting the insertion loss and Returm loss of Balun and TDD

switch, the same Power(+40dBm)is fed to TX directional antenna, My

Question is ,Will the TX Antenna gain(G) would help to increase radiated

power more than 42dBm?

Please help me in understanding more on the inportance of antenna

Gain(G)?

Forward power consists of transmit power minus cable and connector loss,

minus combiner loss (if applicable) plus atnenna gain (in dbi) = EIRP

Example: 20 Watts = +43 dbm - 3 db cable loss = +40 dbm, plus 15 dbi of

antenna gain = +55 dbm EIRP

http://www.satcom.co.uk/article.asp?article=21

[get this widget]

Read More...

W I M A X R E C E I V E R S E N S I T I V I T Y

I have some problem to understand the Sensitivity Calcutaion in IEEE

802.16e-2005.

For the OFDM PHY, at page 351 of the standard (Receiver Requirements), the

sensitivity is scaled by the number of active subchannel (for example in

downlink i can use only one among 16 channels).

In the OFDMA part (page 646, Receiver sensitivity) in the expression appear

Nused*(Fs/Nfft), where I understand that Nused are all subcarrier except DC

subcarrier.

So, there is a difference in the calculation. For the OFDMA the expression

rapresent the minimum received power that guaranted a BER of 10^-6, in

the case of the end user in uplink used all the available channels.

This is the worse case, infact the subcanalization has the following

advantage:

1) the trasmitter power is concentrated in a limited bandwidth, so this can

increase the coverage

2) the Bandwith, in the expression of sensitivity, is smaller, so the minimum

received power is less that in the case of all sub-channel allocated to one

user.

Can anyone explain me the difference?

Receiver sensitivity is a factor of bandwidth as follows:

Receiver sensitivity = -174 + 10log BW + NF of receive amp

so, the narrower the bandwidth the lower the noise, hense the lower the

receive thereshold for narrower BW.

The Standard 802.16e (I refer to OFDMA) specify:

Rss=-114+ SNRrx - 10log(Repetition Factor) + 10log( FS x Nused / Nfft) +

ImpLoss + NF

Where, in according to the definition of "Nused", the term "Fs x Nused / Nfft"

is practicaly the bandwidth occupied by all sub-channels.

So, this is the minimum sensitivity for a user that use all available

subchannels (in OFDMA). But if a MS use only one subchannel, the BW is

narrow hense the receive thereshold is lower.

If I use this expression for sensitivity calculation I have the worst case

results, because the expression don't take in account the effect of

subchanalization.

Is this true?

Maybe, I think I can take in account the canalizazion effect as a Gain in the

link budget (One gain for the power concentration in a sub-channel, and one

gain to compensate the fact that the sensitivity, in reality, is better).

But my problem is: "how can I foreseen the canalization gain if I don't know

how many sub-channels the scheduler of the BS allocate for each user?"

Download the 802.16e standard (if you haven't already) and do a "find" on

the key words "Link Budget". You will find your answers here.

I started to try to describe Link Budgets and Path Balance but they do a

better job than I do.

"Receiver sensitivity = -174 + 10log BW + NF of receive amp"

What's NF? Is this equation valid for single carrier modulation?

-174 is the thermal noise floor, 10log BW applies to bandwidths, run a couple

of exercises, try 200 khz, then 1.25 Mhz then 5 Mhz, etc.

NF is the noise figure of the receive amp. BTS amps run around 5-7 db,

smaller cellphone amps run higher.

Receiver threshold is the amount of receive signal required to obtain a

certain throughput at 1 x 10-6

What about this equation Rss= SNR-10log(BW/Rb) + Nw +Nf

Nw:thermal noise floor ; Rb: data rate (b/s)

is it equivalent, there is an extra term (SNR+logRb).

An other question: the required SNR have to be calculated or is given, what's

the formula if yes?

The signal part of the equation depends on the strength of the recieve signal.

The noise part is dependent of the bandwidth of the receive filter. The next

factor to understand is the interference, because the determining factor for

throughput will be decide by the type of modulation and coding, and that is

determined by the Signal to Noise + Interference sometimes written CINR for

Carrier to Interference & Noise Ratio or C/N+I.

I was referred to this equation just to have relation between the range and

the throughput, actually I forgot the source.

Also I’m working with the following formula:

Rss=-174+10 log(BW(Hz))+SNR+NF+10log(Nsubchannels)

Referring to an example of BL attached. Also I use these values of SNR:

Modulation coding rate SNR Rx

BPSK ½ 6.4

QPSK ½ 9.4

QPSK ¾ 11.2

16-QAM ½ 16.4

16-QAM ¾ 18.2

64-QAM 2/3 22.7

64-QAM ¾ 24.4

Are those values valid for all bandwidths (exactly 25MHz)?

Other question, what are the typical values of antenna gain? directive=17

dBi; omnidirectionnel=0 dBi what about sectoriel?

[get this widget] Read More...

M O D U L A T I O N

Dear Friends,

Can any one share the info about the ideal values of CINR and RSSI vaule at

different bandwidth and modulation.

Bandwith : 3 , 3.5 ,6 6.5 MHz

Modulation :

BPSK ½

QPSK ½

QPSK ¾

QAM 16 ½

QAM 16 ¾

QAM 64 2/3

QAM 64 ¾

please note that the values differ from vendor to fendor.

The following table referes to a 3.5MHz BW System:

Typical levels for BER <1x10-6 are given.

Modulation / FEC / Rx Sensitivity / CINR

64QAM 3/4 -80.0dBm 23.0dB

64QAM 2/3 -82.0dBm 21.0dB

16QAM 3/4 -86.0dBm 17.0dB

16QAM 1/2 -88.0dBm 15.0dB

QPSK 3/4 -92.0dBm 11.0dB

QPSK 1/2 -94.0dBm 9.0dB

BPSK 1/2 -98.0dBm 5.0dB

these values are for BER <1x10 E-6, and they tend to produce a packet loss

of about 1x10 E-2 which is fine for TCP, but a murder for UDP/RTP

multimedia.

Also, consider faster scheduling types in case multimedia is a key role of

your network. Check for performance with short packets - ther may be some

surprises with latencies and throughput ;)

This information is provided by the vendor. The vendor will provide a

minimum signal strength to achieve each modulation/coding scheme.

The noisie floor is dependant of the bandwidth (-174 + 10logBW/hz) plus the

Noise Figure of the receive amplifier. The NF will vary by vendor and will also

vary if set at the top of the tower (close to the antenna) or on the ground

(typically in the base station).

Frequency reuse will increase the signal strength requirement (S/N+I)

[get this widget]

Read More...

F R E Q U E N C Y P L A N N I N G

Which is the best plan for frequency reuse in wimax. Moreover how

important is the synchronization of BTS.

What kind of equipments -BST do u use TDD or FDD?

"Synchronized TDD"

As PMP networks are built out and carriers obtain a larger mass of

customers, channels within each

base station will need to be reused for maximum capacity to serve a growing

customer base. Once the

same frequency begins to be reused in a given base station (or FR greater

than 1), additional complexities

for RF planning must be considered. Although both TDD and FDD suffer

greater interference issues in

this more built-out network, the unique pattern for TDD of base station- base

station interference

becomes much more acute. The solution is to implement intrahub and

interhub synchronization.

In addition, with TDD, no guard bands are required to separate upstream and

downstream frequency

traffic. Usually as much as 200 to 300 MHz frequency separation is needed

between transmit and receive

frequencies for cost-effective modem designs in FDD.

I would suggest a BS with 4 sectors, each 90 deg. (180deg. antennas are

expensive and difficult to obtain).

What do you meen with "different polarity" - I assume you meen polarization.

Is that right?

I also added a pic to explain the frequency reuse plan.

Regards

Harald

Attachments

FrequencyPlan.JPG, 37 KB

Thanks Harald, yes u are right I mean polarization. by 180 degree i meant that i use four sector, let say Sect A, B , C and D. Sect A and C (that are 180 apart from each other) will use the same frequency but one horizental and other vertical and sect B and D will use diff pair of frequency with same arrangement.

Are you not concerned about working with different polarizations in the same network on one BTS? I think for mobile you should stick to vertical polarization. What planning tool are you using? CINR statistics will be needed to analyze your network performance, deploying this frequency plan.

I have the same doubts like Aleks about separating sectors only by polarization:Imagine if sector A and sector C are transmitting on the same frequency (even with different polarization) the antenna in sector A with its finit front-to-back ratio will fire also into sector C. This will effect CINR in sector C. The same will happen also on sector A.

Typical values for a 90deg antenna are:gain: 15.5dBihor plane: 90degver plane: 6.7degfront ot back ratio: 25dB

CINR will be affected considerably, taking into account these typical values.I have one question a little out if this discussion, but it may be useful. What are the typical values of which I can put between the adjacent frequencies as described in the screenshot? Also, how can I calculate the separation in dB needed between the adjacent carrier frequencies?

I will need it when I input the frequency plan in order to get a correct CINR analysis.

Thank you in advance for your time and consideration.

Kind regards,

Aleks

Attachments

carriers.JPG, 41 KB

depending on the modulation, bandwidth, FEC and required BER you need the following SNR: please see uploaded pic SNR.jpgThe table gives you an overview how modulation, bandwidth, FEC and minimum receive level are related. Data are derived from Source: WiMAX ForumConformance Testing to IEEE Std 802.16-2004—Part 3: Radio Conformance Tests (RCT) for WirelessMAN-OFDM™ and WirelessHUMAN (OFDM)™ Air Interface

Now it is up to you to provide this SNR!Check your transmit spectrum and then deside how far you have to separate your carrier frequencies.

Kind regardsHarald

Attachments

SNR.JPG, 71 KB

RX-Selecitivity.JPG, 42 KB

in the Specification Data Sheet from a WiMAX Vendor I found that the attenuation fromchannel n to channel n+1 (the adjucent channel) is 31dB, and fromchannel n to channel n+2 is 50dB.

Well, in all mobile networks I have seen vertical polarization is used. This is based on the specifics of radio propagation in this frequency band and antennas. As you know the propagation method for frequencies above 1800

MHz is reflection, not diffraction. I can send you a document, describing the reasons for what I am saying.

Also, mixing polarization typed in one network is not adviseable, according to my understanding and what I have been taught in university and training courses. And I am pretty sure that vertical polarization is well enough for a mobile network.

Actually, there is no need for a certain polarisation in areas potentially covered with mobile WiMAX, as there is no notable difference in propagation for such small cell footprints. Also, you can't expect any mobile device to operate with only one polarisation. To tackle it, you have various diversity schemes, so called x-polarisation being the most popular in mobile networks. With MIMO, and somewhat elaborated antennas, it is all dealt with in a convenient way,and you don't have to worry about it ;)

the amount of bandwidth you need depends on you services.What type of services have you planned?Depending on your type of service for example, latency varies from vendor to vendor within the same configuration significantly.Our round trip delay measurement results areVendor A: min. 28ms, max. 45ms (useful for VoIP)Vendor B: min. 146ms, max. 509ms (not useful for VoIP, caused by high delay and jitter)So you have to find out if you can live with it or not.

ATPC:Automatic Transmit Power Contrrol (ATPC) is a feature that allows the system to self-optimize the transmit power and provide for the best overall link performance. The ATPC function automatically will adjust the output power level of remote-end systems to match a pre-specified signal strength value.

When ATPC is enabled, the system will attempt to establish the wireless link and exchange performance information. Once the wireless link is established, the master-end system will dynamically adjust the remote-end systems transmit power to maintain optimum link characteristics while minimizing power output. In short, ATPC optimizes the transmission power for best operation, while minimizing excess power and interference with other devices.

Practical examples:Vendor X: BS adjustable from +13dBm to +28dBM, CPE adjustable from -30dBm to +20dBmVendor Y: BS adjustable from +22dBm to +35dBM, CPE adjustable from -27dBm to +24dBm

I just wanted to add to my previous message that apart from output power adjustmentthe dynamic range of ATPC is around 40dB to 45dB depending on vendors specification.

[get this widget] Read More...

T T G , R T G

In the standard 802.16 -2004 I found that TTG must be > to 200µs and RTG

> 5µs.

Must in reality, how long, in average, are RTG and TTG?

Transition Gap

Transmit/receive transition gap (TTG)

- A gap between the downlink burst and the subsequent

uplink burst in a TDD transceiver

- During TTG, BS switches from transmit to receive mode

and SSs switch from receive to transmit mode ( TDD switching timing:

( 13µs <> with SOFDMA modulation

Receive/Transmit transition gap (RTG)

- A gap between the uplink burst and the subsequent

downlink burst in a TDD transceiver

- During RTG, BS switches from receive to transmit mode

and SSs switch from transmit to receive mode ( TDD switching

timing 13µs <> with SOFDMA modulation

- The gap is an integer number of PS durations and

starts on a PS boundary

The IEEE specifications define TTG and RTG in terms of Physical

Slots. A Physical Slot (PS) is a duration calculated as:

PS = 4 / Fs

Where Fs is the sampling frequency, which can roughly be

calculated as Fs = n x BW. Where n is the sampling factor and BW is

the channel bandwidth. The values of n are available in the IEEE

specifications as well.

The WiMAX profiles released by the WiMAX Forum have a list of TTG

and RTG values (in terms of PS) for different channel bandwidths.

See

http://www.wimaxforum.org/technology/documents/WiMAX_Forum_

Mobile_S...

According to the profiles,

TTG = 296 PS for 10 MHz, 218 PS for 8.75 MHz, 376 PS for 7 MHz,

148 PS for 5 MHz and 188 PS for 3.5 MHz

RTG = 168 PS for 10 MHz, 186 PS for 8.75 MHz, 120 PS for 7 MHz, 84

PS for 5 MHz and 60 PS for 3.5 MHz

And, both should be at least 5 micro sec.

These values, of course, depend on the Frame Duration as well,

which is set to 5 ms by the Profiles.

The effect of TTG and RTG durations on coverage, or rather cell

coverage limit, comes from the fact that in TDD systems, if the

propagation time delay between the base station and the receiver is

higher than the lowest of the two values, i.e., Lowest(TTG, RTG), the

downlink and uplink subframes from different base stations will

overlap creating uncorrectable UL-DL interference. And, the receiver

will no longer be able to differentiate between the useful data it's

getting in DL from its base station, and the interference it is

receiving on the UL from nearby mobiles. Plus, the base station will

not be able to get the UL transmission from this mobile in time, i.e.,

it will receive the UL transmission from the mobile during the DL

subframe.

The coverage limit of cells with respect to the TTG and RTG

durations can be calculated as:

Maximum Coverage Range (m) = Lowest(TTG, RTG) x 300000 / 2

Where TTG and RTG are in ms, 300000 m / ms is the speed of

electromagnetic waves (speed of light, you can also use 299458.792

if you want ;-), and the division by 2 takes into account the round-

trip time.

[get this widget]

Read More...

A S N P R O F I L E S

Attachments

16ng-4.pdf, 211 KB

technical_overview_and_performance_of_hspa_and_mobile_wimax_reva.pdf, 667 KB

Attachments

CarlbergDammander.pdf, 947 KB

Attachments

WiMAX_Network_Architecture.pdf, 3.1 MB

[get this widget] Read More...

C A L C U L A T I O N

Fade Margin Calculator is used for estimating the link energy parameters and

for upstream/downstream speed prognosis.

http://www.infinetwireless.com/Support/antenna_calc

http://www.calculatoredge.com/

http://www.rfglobalnet.com/content/misc/showdoc.asp?docid=

%7BFC228779-26E6-4B47-8C9C-73428BFBA44F

%7D&enableLeads=0&VNETCOOKIE=NO

http://www.lx.it.pt/cost231/final_report.htm

http://www.pizon.org/radio-mobile-tutorial/index.html

[get this widget]

Read More...

C A P A C I T Y P L A N N I N G D I S C U S S I O N

Noise is a factor in the frequency domain (C/I) and the time domain (Eb/No-

minimized by multipath)

Signal to Noise Ratio can be improved by using multiple antennas (simple

diversity), maximum ratio combining, guard band between bits (to negate

the destructive effect of ISI), space time coding, Spacial multiplexing and

beam forming.

Since Wimax uses all of these techniques it is very difficult to determine

what state any particular carrier is in at any particular time. Adaptive

Modulation and Coding along with Adaptive Mode MIMO (switches between

matrix A-Space Time Block Coding and Matrix B-Spacial Multiplexing) provide

a system in a constant state of change.

The amount of multipath at each CPE cannot be predicted.

AAS shows the best ability (theoretically) of improving C/I but negates the

Inter Symbol Interference gains (ISI) of MIMO and guard bands (time).

Capacity considerations are: (using John Little's Law of Queueing)

Time in System = Waiting Time + Service Time

Number in System = Number Waiting + Number Being Served

Arrival Rate = Number Waiting / Waiting Time

Number being Served = Arrival Rate x Service Time

Number Waiting = Arrival rate x Time Waiting

Delay Probability = Link Utilization

etc, etc, etc..... It's a lot more difficult that using an Erlang B chart for voice.

I highly recommend attending the Wimax RF Designer Certification course

offered by the Wimax University if you are going to design and operate a

Wimax network.

A really good Wimax RF planning tool will be able to calculate capacity,

queueing, and take into account the effects of Adaptive Modulation and

Coding (BAND AMC), Adaptive MIMO (switches from Matrix A to Matrix B) and

closed loop MIMO (Beam Forming).

I look forward to your comments......

Coming from the TDM voice world to flat IP networks, it was unusual to

transition to a paradigm of soft-capacity (CDMA has soft capacity, but blocks

calls per Erlang B). The more load you put on an IP network, simply the

longer the packet delay. There's no blocking, the load is just absorbed

(unless you run out of buffer, which is a huge problem because it doesn't get

rid of the excess load, TCP just resends it on top of the other data already

trying to be sent, exacerbating the problem). This why call blocking (and

QOS) implemented on a VoIP network is so important (via SIP or proprietary

means), because if the load is too big, latency and jitter become intolerable,

and ALL calls get screwed.

Radio Resource Management systems are expected to be the most difficult

for vendors to develop (and biggest area of vendor differentiation). The

capacity of the system will be heavily dependent on these algorithms. It has

to marry pure capacity schemes (preference to high SNR) with fairness (low

SNR equally needing BW); throw in inter-cellular subcarrier sharing

(fractional reuse), 5ms traffic decisions ,and QOS, and it becomes a monster

traffic engineering problem. I've read of weighting algorithms whereby the

probability of getting resources is dependent on SNR and how long you've

been stuck in the Queue. What they try to do is wait and see if you get a

better SNR later on, so high SNRs get privileged in the short term (unfair, but

higher capacity vis-à-vis modulation/FEC state), but equal fairness in the

long-term. Fun, fun….

Some capacity-related docs attached...

Attachments

ChannelCapacity.pdf, 253 KB

CDC04.pdf, 119 KB

InOWo2004.pdf, 107 KB

There are many variations of throughput. Remember that the best modulation scheme is 64 QAM offering 6 bits / hz and the best coding scheme is 5/6. Give this perferc scenario the available throughput would be 25 Mb/s per sector. Of course not all users will be 64 QAM and 5/6, and not all of the sub-channels are used for data, so the actual throughput will be less. Adding MIMO will help to acheive the highest rate possible.

Here is a chart to help visualize the possibilities.

Attachments

OFDMA rates.jpg

[get this widget] Read More...

L I N K B U D G E T A N D P E N E T R A T I O N

The link budget is used to determine the maximum allowable path loss for a

BALANCED LINK. The purpose is to ensure that the CPE can talk back to the

base station.

The higher the frequency the faster the rate of attenuation, the less distance

covered. Remember

Path Loss = 32.45 + 20*log D(km) + 20*log F(Mhz)

WiMAX is not like CDMA with RW and no of RWs available to use. There is no

concept of RW per radio in WiMAX. In WiMAX, it is all about Service Flows

that can be supported in each radio. The larger the number of SF created in

a radio channel, the smaller each SF bandwidth will become. To counter this,

WiMAX support packet priority and CIR /MIR to allocate this valueable

resource accordingly (bandwidth) per SF.

64QAM means higher throughput but needs good SNR to achieve. BPSK is

less demanding on SNR and give you lowest throughput. This is the

modulation usually used for acquisition of the radio link to ensure the best

chance of getting a 2way comms with the BS. For BPSK operation at non LOS

condition (one brick wall blockage), the range could be 3-4km. General rule

of thumb is, a single brick wall gives around 10dB attenuation, metalise

window could give as much as 20dB attenuation. So if you can get 64QAM

operating at -70dBm, shuting a metalise window could drop you down to

BPSK operation.

1) Yes, you do have a link budget for each modulation scheme, more

specifically you would create a link budget for the Pilot/Preamble, UL/DL MAP

channels and then the UL/DL traffic channels with the most robust

modulation scheme. Choose the weakest link, and the MAPL from that will

define you cell range.

I recall a WiMAX Forum document with example link budget in this regard (I

beleive the title of the document contains "Part 1: Technical description").

2) I'm guessing you mean 3.5 and5.5 Ghz compared to the GSM

850/900/1800/1900 MHz bands. No doubt will you have much lower in-

building coverage/penetration with the higher WiMAX bands compared to the

GSM bands ...

At this stage you will seldom see any real link longer than, say, 5km, and in

this range a link budget is nicely established by power control. Everything

more than that is usually some experimental thing, and there is really no

point of rubbing in the 75Mbps at 30km any more - it washes off.

For any successful wireless business you simply MUST have most of your

users at QUAM 64 3/4 (or better :). To squeeze the most of it, you must have

some surplus juice (for power control), lowest possible installation (for better

reuse – steeper signal decay), cheap installations, and no antenna tilting.

Then it is perfect.

To do that, your footprint gets small, and in case of indoor it gets soooo

small that WiFi becomes equally viable solution.

Link budget 2.doc

mobile_wimax_deployment_alternatives.pdf

[get this widget]

Read More...

R E C I E V E N O I S E F L O O R Q U E S T I O N

The RSSI for FIXED wimax says that measurable rx powers should be in the

range of -40 to -123 dBm.

My question is can we acheive a sensitivity of -123 dBm for any combination

of bandwidth and modulation scheme in wimax. BPSK 1/2 scheme requires a

SNR of 3dB. Hence the noise floor of the receiver should be around -126dBm,

if at all -123 dbM sensitivity can be obtained by BPSK using

subchannelization.

The noise floor values using the standard -174+10log(BW)+NF is higher than

-126 dBm for 1.25 MHz bandwidth.

Can someone please explain which modulation gives a -123 dBm sensitivity.

And also how the noise floor should be better, ie < -123 dBm.

-----

Related Answers:

Actually, it is possible to go deeper in case your receiver can sub-divide a

channel into smaller chunks, and thus reduce the BW component. However,

you can't go infinitely with this concept, and you are limited with

subchannelization to one single but whole subchannel, and this concept

might make sense only in case you have multiple receivers (for pilots, etc.)

-123 dBm (with 3 dB SNR) stands for 63kHz bandwidth, and it is reduced

somewhat in case of a realistic receiver NoiseFigure of ~4dB - down to

25kHz. It is just about enough to encompass a whole subchannel in a 3.5Mhz

OFDM channel.

These multiple receivers are realised via serious DSP computing, and it is

somewhat different than the original FFT concept of OFDM. What goes

around - comes around.

WiMAX don't have BPSK scheme, I think QPSK 1/2 repetition 6 would be most

robust MCS in WiMAX.

I don't know the meaning of "measurable". Does this mean "decoderble"?

And, I can't believe the sensitivity of any MS in WiMAX can meet -123dBm.

It's really perfect one.

I think -123dBm only consider AWGN noise and very very good SNR.

Normal situation in field does not show the 10dB SNR(example of good

signal) and -123dBm RSSI.

-123 dBm means the edge of cell and SNR would be going to 0dB or negative

SNR.

And, required SNR of data burst and preamble or control signals are different

also.

Anyway most robust one is QPSK 1/2 repetition 6.

There are some things one must separate mentally when considering any

technology, otherwise it all falls into apples-pears kind of confusion.

Remember the 20 miles and 70Mbps tantrum? If all calculations are done

correctly you'll always get the same result, regardless of the approach. The

only necessary thing is to keep your apples together from beginning to the

end, OR pick pears and stick with them to the end.

How it works? All communication can be expressed as energy per bit. Energy

for all bits over full bandwidth running at some bitrate is total power of a

system (apples). It can be seen as power density divided into sub-bands, and

you get portions of power over smaller bandwidths with single subchannel as

a unit (pears). Whatever approach you pick - end result is the same.

Point with OFDMA is that using small total power divided into small number

of carriers you can reach further. To facilitate calculation it is customary to

observe a single subchannel's behaviour (pears). Nothing else.

You should find exact meaning of -40~-123 dBm

I think -123 dBm is come from "dBm per minimum data burst unit(It's termed

tone in WiMAX)

I don't know exactly what FFT size is used in 1.25MHz BW.

If 128 FFT is used in your system, -134 dBm is calculated from your formula.

And -40 dBm may be come from full BW usage.

[get this widget]

Read More...

M O D E L T U N I N G P R O C E D U R E

1. Set your planning tools correctly, i.e. Equipment, Antennae masks, output

powers, etc...

2. Focus on one region, which contains the major clutter types: dense urba,

suburban, rural...etc...

3. Examine your map data and preferably you should get map data with high

resolution. Set the inital clutter attenuations as they are very important.

4. Run a simulation and produce a coverage plot.

5. Go on drive tests in this area.

6. Visualize the drive tests and run a report to see the delta between the

planned and measured data. Chech the error report as well, (RMS...)

7. Edit some of the parameters in the propagation model and some of the

clutter attenuations.

8. Run a coverage plot again.

9. Go on drive tests, visualize and prdouce comparison report.

10. if you fit in less then 5dB error from the simulation, you have done well. If

not...continue working.

Model tuning is very very demanding in terms of knowledge and experience,

but you must strive to do it. This is the way. Also I am again asking to refer

to the other topics on this. There are very good detailed explanations.

1. ALL models work as more or less linear functions against the log distance.

When tuning a model, you need at least a whole decade of distance included

in your drive test (e.g. 100m to 1km, or 300m to 3km), and your drive test

points density must be spread linearly against the log distance. This requires

as many points you can gather near to the base station, and only a selected

few on different clutters at far side.

2. Always perform Lee transform (decimation) prior to model tuning to

exclude Rayleigh from equation.

3. Validity of a model is checked by filtering out a group of points that have

some distinct feature, e.g. LOS, and see if your average difference

(measured against model) remains zero. If not - try harder.

4. RMS errors smaller than 7 dB are fine.

5. Do it by hand, and tune a single parameter at one time, observe RMS error

average difference, and if possible observe a difference distribution plot - if

you observe two or more distinctive "hills" there - your cartography may be

wrong or your clutters are not selected appropriately.

6. Take time.

A final report of COST-231 can be downloaded at:

http://www.lx.it.pt/cost231/final_report.htm

Mr. Coreia usually makes a book out of a final report, and sells it while it is

hot. This one is not that hot any more, and it is a perfect starting point for

serious researcher. Unfortunately OFDM is not included.

About the Lee criterion and how to collect and decimate drive test data see

this: http://whitepapers.zdnet.co.uk/0,1000000651,260090593p,00.htm and

it requires a free registration

[get this widget]

Read More...

W I M A X S P E C T R U M E F F I C I E N C Y

The capacity of each sub carrier depends on the modulation order, which can

be BPSK (1 bit per sub carrier), QPSK (2 bits per sub carrier), 16QAM (4 bits

per sub carrier), or 64QAM (6 bits per sub carrier) in the case of the OFDM

PHY. In general more power is required for using higher order modulation in

order to achieve the same range performance.

In the OFDM PHY there are 256 sub carriers spanning the sampling spectrum

which is defined as:

Eq. 1) Fs = FLOOR(n · BW / 8000) · 8000 ,

Where n is the sampling factor, a constant dependent on the channel size,

and BW is the channel size in units of Hz. The number of sub carriers

corresponds to the size of the FFT/IFFT used to receive and transmit the

OFDM symbols. To reduce the complexity of the digital processing algorithms

it is desirable to use FFT sizes that are powers of 2.

For channels in the 3.5 GHz band the licensed channels are multiples of 1.75

MHz and n = 8/7. For a channel width of 3.5 MHz the sampling spectrum is

4.0 MHz. The 256 sub carriers are equally distributed across the sampling

spectrum implying a spacing of:

Eq. 2) Δf = Fs/256 .

For example Δf = Fs/256 = 15,625 Hz for a 3.5 MHz channel.

Notice that changing the channel width changes both the sub carrier spacing

and the symbol time. This implies a range of practical channel sizes for fixed

applications but quickly becomes unworkable for mobile applications where

the design approach of scaling the FFT size to the channel width is used with

the OFDMA PHY.

In order to provide increased inter-channel interference margin and ease the

radio filtering constraints, not all of the 256 sub carriers are energized.

There are 28 lower and 27 upper “guard” sub carriers plus the DC sub carrier

that are never energized. Of the 256 total sub carriers therefore, only 200

are used which leaves a total occupied spectrum of Δf · 200 = 3.125 MHz for

a 3.5 MHz channel.

This example implies a raw, occupied bandwidth efficiency of 89% (3.125/3.5

= 89%), but the number varies for other channel bandwidths and sampling

factors. This is the first example we have encountered of what can be

considered to be channel overhead that decreases the channel capacity, in

this case it is required by design to improve the channel quality when

adjacent spectrum is occupied.

Not all of the 200 occupied sub carriers are used to carry data traffic. There

are eight pilot sub carriers that are dedicated for channel estimation

purposes, leaving 192 data sub carriers for user and management traffic. In

order to calculate the raw channel capacity it is useful to understand how

many bits each data sub carrier can carry.

The raw sub carrier capacity, before taking out the overhead added by

redundant error correction bits, is given by the modulation order: 6 bits/sub

carrier for 64QAM, 4 bits/sub carrier for 16 QAM, and so on. For example, a

channel able to support 64QAM modulation could send six bits for each data

carrier per symbol. But how long is a symbol?

The orthogonality of the sub carriers is achieved by maintaining an inverse

relationship between the sub carrier spacing and the symbol time. So the

useful symbol time is just the inverse of the sub carrier spacing:

Eq. 3) Tb = 1/Δf.

For example, a 3.5 MHz channel has a useful symbol time of 1/15625 = 64

us. However for multi-path channels, we must make allowances for variable

delay spread and time synchronization errors. In OFDM, this is accomplished

by repeating a fraction of the last portion of the useful symbol time and

appending it to the beginning of the symbol for a resulting symbol time of:

Eq. 4) Ts = Tb + G · Tb,

Where G is a fraction:

Eq. 5) G = 1/2m, m = {2,3,4,5}.

The repeated symbol fraction is called the “cyclic prefix”. Larger cyclic prefix

implies increased overhead (decreased capacity since the cyclic prefix

carries no new information) but larger immunity to ISI from multi-path and

synchronization errors.

For a 3.5 MHz channel the useful symbol time is 64 us and the minimum total

symbol time is Ts = 64 us + 64/32 us = 66us. The raw channel capacity per

symbol is:

Eq. 6) Craw = 192 · k / Ts,

Where k is the bits per symbol for the modulation being used.

Assuming 64QAM modulation (6 bits per symbol):

192 data sub carriers x 6 bits/sub carrier / 66 us = 17.45 Mbps.

Notice that the modulation rates are designed so that an FEC coded block

just fits in one symbol time when all 192 sub carriers are used.

For instance for 64QAM, 144 Bytes = 1152 bits / 6 bits/symbol = 192 sub

carriers.

The useful channel capacity per symbol is:

Eq. 7) C = Craw x OCR,

Where OCR is the overall coding rate given in the table. For example, for a

3.5 MHz channel the useful channel capacity per symbol assuming the

highest rate modulation and coding is:

C = 17.45 Mbps x 3/4 = 13.1 Mbps.2

It is useful to summarize the discussion of the channel capacity is terms of

the spectral efficiency. Spectral efficiency is expressed in units of bits per

second per Hz and is obtained by dividing the channel capacity by the

channel width:

Eq. 8) E = C / BW.

We can see that our 3.5 MHz channel has a spectral efficiency (so far) up to

13.1 Mbps / 3.5 MHz = 3.74 b/s/Hz. The spectral efficiency is a useful figure

of merit to keep in mind because it lets you quickly calculate the capacity for

other channel sizes that WiMAX supports.

2 By now at least some readers must be wondering what happened to the

often-hyped 75 Mbps channel capacity for WiMAX? Taking the very largest

channel size, 20 MHz, highest coding rate, and minimum cyclic prefix, the

raw channel size using equation 6 is: Craw = 192 x 6 b/sub carrier / 11.3 us

= 102.0 Mbps.

The useful channel size from equation 7 is: C = Craw x ¾ = 76.5 Mbps. Of

course we have said nothing about the (short) range of such a hypothetical

channel, and we should be aware that this is before taking out other PHY and

MAC layer overhead that, as we will see, is significant. To be blunt, talking

about 75 Mbps WiMAX channels for MAN applications is about as meaningful

as quoting the top end speed marked on the speedometer of a family

minivan.

[get this widget]

Read More...

U L T R A C O M P A C T 2 G / 3 G D U A L - M O D E R F T R A N S C E I V E R

US : Renesas Technology America, Inc. today

announced the R2A60281LG, an ultra-

compact 2G/3G dual-mode radio frequency

(RF) transceiver that supports both the 2G

and 3G modes used in cellular

communications. The device integrates in a

single chip most of the high-frequency signal

processing functions required by mobile

phone handsets, including the down

conversion of high-frequency wireless signals

to a lower frequency to be used by the

baseband processor.

The R2A60281LG is only 7×7×0.6 mm

(about 20% smaller than previous solutions). It combines multiple functions

and eliminates the need for an analog baseband processor. Therefore, it will

facilitate the development of smaller and thinner handsets for GSM and W-

CDMA/HSUPA/HSDPA networks used as the global mobile telephony

standards. The transceiver also can be applied in 3G communication cards

for PCs.

Multiple industry trends are driving the need for the new transceiver. Many

mobile phone users are expected to replace older phones with global 3G

models that also support the GSM (2G) standard. At the same time, there is a

growing demand for handsets that support more than one frequency band.

Feature-rich handsets offering an array of multimedia functions, such as

terrestrial TV broadcast reception, are becoming more popular, making it

necessary to mount more electronic devices on handset circuit boards, even

as the handsets themselves become thinner. The new transceiver builds on

previous Renesas RF transceiver technology and addresses these trends by

supporting multiple frequency bands and both the 2G and 3G modes, while

also offering faster operation and a smaller, thinner package.

Specifically, the R2A60281LG integrates 2G (GPRS/EDGE) quad-band

(850MHz/ 900MHz/ 1.8GHz/ 1.9GHz) and 3G (W-CDMA) quad-band (800MHz/

1.5 GHz/ 1.7 GHz/ 2 GHz) functionality into a single chip. It also supports

High-Speed Downlink Packet Access*1 (HSDPA) categories 7 and 8 for fast

data downloads at speeds up to max. 7.2 Mbps as well as High Speed Uplink

Packet Access (HPUPA). The chip is built in 0.18 micrometer Bi-CMOS

technology.

The transceiver includes the low-noise amplifiers (LNAs), a loop filter*2

circuit, HPA controls and more. A filter supporting CDMA2000 attenuates

wavelengths outside the desired frequency band, reducing susceptibility to

radio frequency interference (RFI). Also, a 312Mbps (max.) digital interface

function supports 3G DIGRF operation, offering the A/D and D/A conversion

functions formerly handled by an analog baseband processor. This interface

enables high-speed exchanges of In-Phase/Quadrature-Phase (I/Q) and

control data with a digital baseband processor, for quick transfers of large

data volumes.

The R2A60281LG 2G/3G dual-mode RF transceiver looks to the future, as

well, by also supporting the 1.5GHz band under the specifications newly

standardized by the Third Generation Partnership Project (3GPP), an

international body for establishing 3G mobile phone standards. Renesas’

development plans for RF transceiver products include new chips offering

support for the 3G-LTE*3 and 4G modes that will enable even faster

communication speeds.

Prices and Availability

Product

Name Package

Sample Price/

Availability

R2A60281LG 120-pin

LGA $9/ March 2008

Note 1 HSDPA: High-Speed Downlink Packet Access. This high-speed

s: .

packet communication standard is an extension of W-CDMA. It can

be thought of as 3.5G relative to 3G. HSDPA supports downlink

packet communication at speeds up to 14.4Mbps. Category 8

supports a maximum data transfer rate of 7.2Mbps.

2.

Loop filter circuit: The circuit that determines the frequency

characteristics of the phase locked loop (PLL) circuit, which controls

the oscillator. The input signal is compared to a signal generated

internally by the circuit in order to detect shifts in frequency or

phase. The detected error is fed back to the oscillator, and the

output signal is generated. A loop filter circuit requires a high level

of calibration accuracy.

3.

3G-LTE (Long-Term Evolution): The terms "3G Long-Term Evolution"

and "Super 3G" are both used. The system supports maximum

communication speeds of 100Mbps for downloads and 50Mbps for

uploads.

[get this widget] Read More...

M O B I L E W O R L D C O N F E R E N C E A N N O U N C E M E N T S

The Mobile World Congress 2008 moves into high gear today, bringing

together some 13,000 companies and 100,000 visitors in Barcelona. The

GSM Association, which sponsores the show, is the global trade association

representing more than 690 GSM mobile phone operators across 214

territories and countries of the world.

Google’s Android mobile platform will be demonstrated (video) on a Texas

Instruments-powered handset while new handsets are being rolled out by

Sony Ericsson, with 10 new phones, Samsung with eight new products, and -

megapixel camera uploads directly to Flickr with geotagging.

Nokia four new mobile phones. The Sony Ericsson C702 Cyber-shot uses

built-in aGPS to stamp location data onto every photo you take with its 3.2

MP camera and the Nokia 6220 5-megapixel camera uploads directly to Flickr

with geotagging. LG Electronics and LG-Nortel are demonstrating how LTE

can deliver high-speed wireless Internet.

Some of the announcements today include:

Kineto Wireless is creating a UMA-enabled 3G solution based on NXP’s Nexperia UMTS chips. Unlicensed Mobile Access dual-mode handset services are now focused on delivering UMA phones with 3G capability,” said Ton Van Kampen, vice president of business development for NXP. Kineto’s UMA client software allows customers to seamlessly roam and handover between the cellular 3G UMTS network, the 2.5G GSM/EDGE network, and home or enterprise Wi-Fi access networks.

Broadcom announced a chip offering support for the three most popular open operating systems for smartphones - Symbian, Windows Mobile and Linux. Broadcom also announced a reference design that brings advanced handset features to mass market including a 3.2 megapixel camera with GPS, Wi-Fi, Bluetooth and FM.

Motorola will showcase their ROKR E8 and MOTO Z10 and license its mobile WiMAX chipset reference design, the Motorola WTM1000, and essential IP licenses for the company’s portfolio of patents to third parties in a move designed to encourage the innovation and proliferation of new WiMAX-enabled devices. Motorola also unveiling its first WiMAX chipset reference design licensee. Enfora, a leader in wireless monitoring and asset management applications, plans to integrate the Motorola WTM1000 solution into its suite of eWiDE wireless networking solutions. The WTM1000 chipset-based radio is scheduled to debut in Motorola’s line-up of WiMAX mobile devices for various carriers around the world, including Sprint Xohm.

Sierra Wireless added two new products to its lineup of HSPA mobile broadband modems, the AirCard 885E ExpressCard and the Compass 885 USB modem for use worldwide.

NEC is connecting real world phones to the “Second Life” with their IP Voice and Media Solution. Visitors can enter Second Life and control an

avatar to make calls to another person in the real world by using the NEC communicator.

The WiMAX Forum will hold a media luncheon and news event on the “State of the WiMAX Industry” in Barcelona. This event plans to address expected WiMAX device availability, global network deployments, and updates on mobile certification.

Alvarion announced they will be the first WiMAX vendor to join the HP Developer and Solution Partner Program. Alvarion will demonstrate its end-to-end 4Motion Mobile WiMAX solution based on HP software at Mobile World Congress in Barcelona.

Nokia’s new dual-band HSDPA N96 doubles internal memory to 16GB from the N95, while adding LED lights to the 5 megapixel digital camera for flash and video lighting.

Samsung’s Ultra III U900 “Soul” is a metal-encased slider, only 12.9 millimeters thick, with a 5 megapixel digital camera and face detection along with Bang & Olufsen sound.

Nortel Networks and Motorola both had live LTE radio networks running at the conference, while Qualcomm announced it would begin shipping multimode LTE-CDMA and LTE-UMTS chipsets in 2009.

Cisco will showcase mobility applications to change the way people connect, collaborate and access entertainment on the move including DVB-H, Three-Screen Video and VoIP for Mobile Operators. The Cisco WiMAX Radio demonstration included the Cisco BTX-MX8 WiMAX Basestation, the RFS8 Antenna System, and a selection of Cisco and third-party subscriber stations (customer premises equipment [CPE])

The GSM Association announced that it is partnering with Mofilm to present a short film showcase for mobile phones. The partnership follows the success of last year’s experimental Sundance Film Festival: Global Short Film Project, a collaborative pilot between Sundance Institute and the GSMA.

Mobile Television announcements included an announcement by Carriers Orange and T-Mobile to rollout of a broadcast mobile TV service in the UK this year using existing cellular spectrum and the TDtv technology developed by embedded-software-systems provider NextWave Wireless. Meanwhile, Nokia’s new N-96 featured a built-in DVB-H receiver for digital TV signals in Europe and Asia.

Texas Instruments said it had developed a chip to support cell phones with mini projectors and another chip that would let users record high-

definition video on their phones. TI claims it’s pico projector chips are ready for production.

Qualcomm introduced a slew of new chips including an integrated ARM11 applications processor running at 528 MHz, a multimedia chipset, a seventh-generation gpsOne engine with support for Standalone-GPS and Assisted-GPS modes, and support for Bluetooth, Wi-Fi and FM radios.

Wi-Fi hotspot aggregator Boingo announced an unlimited-use, $7.95-per-month plan for its entire global network of 60,000 hotspots at the 3GSM cell phone trade show today. The inexpensive plan will work on cell phones, PDAs, and a Belkin Wi-Fi phone—just not on laptops. It’s truly $7.95 for unlimited use, according to Boingo’s Jonathan Mendelson.

Spotigo’s Wifi-based Positioning Solution can now be downloaded free from their website. Any WiFi device can be located just by the received WiFi signal patterns.

Nokia made a big splash with its Media Network, an alliance of more than 70 publishers and operators including Sprint, Discovery, Hearst and Reuters. The company claims ads are already yielding average click-through rates of 10% with a potential reach of 100 million mobile consumers. It leverages analytics technology from Enpocket, which Nokia acquired last year. Comverse launched a mobile advertising solution to deliver ads through text, multimedia messaging, visual voicemail, ringback tones and on the wireless Internet while Ad-funded mobile game publisher Greystripe reported a click-through rate of more than 4% during a two-month campaign for Yahoo Inc.’s oneSearch mobile Web portal.

Worldmax, a new broadband wireless access provider in The Netherlands, has selected communications solutions provider Alcatel-Lucent to deploy one of the first commercial WiMAX 802.16e-2005 networks in Western Europe, in Worldmax’s 3.5GHz spectrum.

[get this widget] Read More...

A W S L I G H T S U P T E X A S

Stelera Wireless, an Oklahoma City-based rural broadband service provider

has launched Advanced Wireless Services (AWS) in Floresville and Poth,

Texas, notes Om Malik.

Stelera is a wireless startup that is focused on

delivering broadband services in rural

communities. It owns 42 AWS licenses across the

United States covering almost 6 million people. It

is the first mobile operator to utilize the AWS

band (2.1 GHz and 1.7 GHz) in the United States.

The company will offer residential and business packages that cost anywhere

from $60 to $100 a month. The speeds on an HSPA network are up to 7.2

Mbps downlink and 2 Mbps uplink. The I-HSPA technology from Nokia

Siemens Networks can offer download speeds of up to 42 megabits per

second. Stelera owns 42 AWS licenses across the U.S., mostly in rural

communities.

Leap Wireless is another AWS operator poised to

make a large push into East Coast and Gulf Coast

markets using its AWS spectrum notes RCR News. Leap owns AWS spectrum

along the Gulf Coast, from Corpus Christi, Texas, to Baton Rouge and New

Orleans, La. The East Coast cities where Leap expects to build new markets

include Wilmington, Del.; Philadelphia, Pa.; Washington, D.C.; Baltimore, Md.;

and Richmond and Norfolk, Va.

More recently, Leap and MetroPCS announced a merger, that brought two

large AWS spectrum owners into more direct competition with the largest

AWS spectrum owner in the United States — T-Mobile.

Headquartered in San Diego, Leap Wireless began as a spin-off of

QUALCOMM and now owns licenses for 35 of the top 50 markets, including

Chicago, Milwaukee, Minneapolis, Philadelphia, Washington D.C, and Seattle.

Leap ended 2007 with approximately 2.86 million customers.

MetroPCS, headquartered in Dallas, has more than 3 million subscribers and

holds 23 licenses through its subsidiaries in the South and Central Florida,

Atlanta, San Francisco, Dallas, Detroit and Sacramento metropolitan areas.

Both MetroPCS and LeapWireless (under the Cricket name) acquired

nationwide spectrum in the AWS auction last year.

Top 10 Highest AWS Bidders

BiddersNet total of high

bids1. T-Mobile $4.2 billion

2. Verizon Wireless $2.8 billion3. SpectrumCo $2.4 billion

4. MetroPCS $1.4 billion5. Cingular $1.3 billion6. Cricket $710 million7. Denali Spectrum

$365 million

8. Barat Wireless $127 million9. AWS Wireless $116 million

10. Atlantic Wireless

$81 million

Click here to find out who is backing these bidders.

The FCC’s Advanced Wireless Services auction concluded in September 2006

and grossed $13.9 billion for the U.S. Treasury.

The big winner of AWS spectrum was T-Mobile, which spent some $4 billion

covering virtually the entire country.

As an aside, some observers believe going beyond the $4.7 reserve price for

nationwide 700MHz coverage would be imprudent. But considering you only

need one third the towers at 700MHz for similar coverage, it could be a

comparative bargain. Because 700 MHz is “open”, unlike the AWS band, it

might be tougher for an operator like Verizon or AT&T to rationalize.

But without a legacy cellular network to protect — and a mobile advertising

platform to generate revenue — 700 MHz could be a license to print money

for someone like Google. Research firm Gartner predicts worldwide mobile

advertising revenue will grow from less than $1 billion last year to $11 billion

in 2011.

In related news, Nokia Siemens Networks was also selected by satellite

phone company TerreStar Networks, to deploy Internet-HSPA solution for the

TerreStar all-IP integrated satellite and terrestrial wireless communications

system.

“We don’t have to deal with all of the highways and byways that cellular

carriers have,” said Dennis Matheson, chief technology officer for TerreStar.

“But satellites can’t get to the mass consumer because they disappear into

urban canyons. So we need the HSPA network to fill in the gaps.”

Nokia Siemens says it will be the first commercial I-HSPA network

deployment, a technology that Nokia Siemens helped pioneer.

Their Flexi WCDMA Base Station uses an Internet-High Speed Packet Access

(I-HSPA) architecture, which eliminates legacy circuit-switched technology.

Optimized for native IP applications, including voice and data, I-HSPA is the

only commercially available all-IP solution, and is optimum for edge

deployment within TerreStar’s MSS service, says the company.

“I-HSPA still isn’t a replacement for WiMAX, not providing the bit-per-hertz

efficiency of the OFDMA technology, but it’s not intended to be”, said Mark

Slater Nokia’s VP of sales, in Telephony Magazine. Nokia, in fact, is straddling

both sides of the fence, building a WiMAX portfolio in parallel with its UMTS

(3G) cellular portfolio.

Devices normally connect through a base station and then are routed

through specialized cellular gear before finally hitting the Internet. I-HSPA

eliminates much of that cellular gear, allowing the device to connect directly

to the Internet through a base station. Smooth handoffs between ajoining

cell sites is said to be the downside.

TerreStar Networks, a satellite phone company, will leverage Nokia Siemens

Networks’ I-HSPA technology as the foundation for development of their LTE

(Long Term Evolution) services.

When TerreStar’s network is deployed, perhaps later this year, the company

will provide universal access and tailored applications to millions of users

throughout North America via mass market commercial wireless devices and

spot beams.

TerreStar, which just announced $300 million in investor commitments

through the launch of its hybrid mobile satellite, said Arianespace, the launch

provider for TerreStar-1, has confirmed it can launch the satellite during the

December 2008 through February 2009 launch window.

Competitor ICO also shares those

MSS frequencies and

boardchairman Craig McCaw would

like to use ICO’s frequencies to

carry mobile television as an

adjunct to Clearwire’s Mobile

WiMAX.

ICO plans to integrate its Mobile

Interactive Media (MIM) suite of

services with Clearwire’s

broadband network. “Our next generation wireless personal broadband

networks are built to deliver data, voice and video over a single network,”

said Scott Richardson, chief strategy officer for Clearwire.

If Craig McCaw’s ICO can deliver live television to mobile DVB-SH receivers,

who needs MediaFLO? Probably not Clearwire — or possibly Sprint’s Xohm.

ICO’s first GEO satellite is scheduled to be launched in early 2008 with MSV’s

hybrid service starting in 2009.

ICO’s G1 satellite is due to launch on an Atlas V launch next month by United

Launch Alliance. ULA, by the way, is the product of a merged Evolved

Expendable Launch Vehicle program (EELV) that stuck taxpayers with a

$14.4 Billion bill for cost overuns due to Lockheed and Boeing’s duplicative

rocket programs that ballooned from $17 billion to $32 billion in a few years.

Clearwire, a partner with Intel and Motorola, is committed to Mobile WiMAX,

but I-HSPA handsets could be one option for AWS spectrum holders T-Mobile,

Verizon and AT&T — featuring dual-mode AWS/satphone connections.

[get this widget] Read More...

M O B I L E W I M A X A T W O R L D C O N G R E S S

The WiMAX Forum today announced that 28 Mobile WiMAX products in the

2.3 GHz and 2.5 GHz frequency bands have been submitted for WiMAX

Forum certification since WiMAX Forum labs began accepting applications

from vendors in late 2007. The first Mobile WiMAX products are expected to

achieve the WiMAX Forum Certified seal of approval in Q2 2008 and to reach

the market later this year.

The organization also announced its official support for Mobile WiMAX

certification in the 700 MHz band. Work on the technical specifications for

700 MHz WiMAX Forum certification is already underway in the association’s

working groups. The published specifications will be unveiled as they are

completed and they will support both TDD and FDD certification profiles.

“With more than 260 commercial WiMAX deployments rolled-out on a global

basis, WiMAX technology is the only commercially available OFDMA-based

wireless technology,” said Ron Resnick, president of the WiMAX Forum.

The WiMAX Forum media luncheon featured testimonials from global service

providers, including Freedom4, Iberbanda, KDDI, Korea Telecom and

SprintNextel and who each indicated the readiness of WiMAX technology

with certified products and the optimization of WiMAX networks for

broadband data services as key motivators in selecting WiMAX technology

for their next generation services.

TelecomTV has video reports from Mobile World Congress 2008 (above).

Other WiMAX announcements at the big show in Barcelona:

Redline Communications introduced a full suite of RedMAX 4C Mobile WiMAX products including Mobile WiMAX base stations and subscriber devices for the 2.5 GHz and 3.5 GHz bands. The expanded RedMAX 4C familyx includes Redline’s 2 x 2 MIMO antenna technology which is said to deliver equal performance to competitive 4 x 2 systems, providing greater coverage and a lower absolute cost to operators.

Alcatel-Lucent announced Mobile WiMAX contracts with Worldmax in the Netherlands and Packet One in Malaysia as well as several additional operators yet to be publicly disclosed. Alcatel-Lucent’s commercial 16e deployments worldwide now total 22 - more than any other vendor claims the company.

Intel, through its VC funding arm, said it will make a “substantial” investment in Freedom4 (right), a London-based WiMAX service provider.

The U.S. Army is testing Mobile WiMAX. They took three Samsung base stations and mounted them into Humvees, connected to a satellite link as the backhaul. It is believed to be the first time a satellite link was used with WiMax. Military forces can set up a satellite dish and pop up a WiMax antenna next to it to form “a bubble of WiMax” around a particular area or a convoy, according to testers.

Mitsumi is using Sequans chips for Mobile WiMAX modules in an SD card. The SD card includes all Mobile WiMAX functionality in a small 20X20 mm package.

SEQUANS and Tecom LTD, a leading telecommunications equipment manufacturer of Taiwan, have introduced a comprehensive Tecom WiMAX product series including Mobile WiMAX Wave 2 base stations and subscriber stations using Sequans chip solutions as the main design platform.

Max Telecom today announced it has completed the first phase of its WiMAX rollout in Bulgaria, using the Cisco Mobile WiMAX technology paired with its access and aggregation solutions. Max Telecom plans to expand coverage to 90 percent of Bulgaria’s population by the end of 2009.

[get this widget] Read More...

B A R E N U C K L E S I N B A R C E L O N A : L T E V R S W I M A X

At the Mobile World Congress in Barcelona, the showdown pitting upstart

Mobile WiMAX against Long Term Evolution, backed by heavy weight telcos,

is going head-to-head. At stake is a huge global market for 4G telecom gear

and services that could dwarf today’s 3G.

China Mobile announced today that it will join Verizon Wireless and Vodafone

in a three-way operator trial of Long Term Evolution (LTE), the 4G mobile

broadband standard, says Light Reading. China Mobile is the world’s largest

mobile operator, with over 350 million customers, and may tip the 4G

standards scales in LTE’s favor.

Along with Verizon and Vodafone, the operator joins the ranks of NTT

DoCoMo, which has an aggressive LTE deployment plan and AT&T, which is

expected to make a committment to LTE but has not made it official (yet).

Alcatel-Lucent also announced it is teaming with Japan’s NEC in a joint LTE

venture. Alcatel-Lucent CEO Patricia Russo (left), said the move is an

offensive play, rather than a defensive one.

“It’s about scale, time to market, and pooling existing R&D,” she told

reporters during an afternoon press conference at the Mobile World Congress

in Barcelona, Spain. “This is not a way to reduce our investment.”

The China Mobile trials will

focus on both the frequency-

division duplex (FDD) and time-

division duplex (TDD) varieties

of the LTE standard. The TDD

version of LTE is China Mobile’s

technology choice because it is

an evolution of the Chinese

homegrown 3G standard, TD-

SCDMA.

LTE is a telecom-centric

project. It is not a standard yet,

but it is expected to mold the

new release 8 of the UMTS IP-based standard. LTE’s overriding characteristic

is many telco layers and proprietary protocols.

Most observers believe WiMAX has a 2-3 year lead over LTE.

That may have prompted GSM Association CEO Rob Conway to opine that

WiMAX should become a subset of LTE.

WiMax supporters say it should be the other way around.

“We went from having virtually no products here in Barcelona last year to

having over 40 companies with real products on their stands, so Wimax is

here and it’s real,” said Wimax Forum president Ron Resnick.

Resnick said 28 Wimax products in the 2.3 GHz and 2.5 GHz frequency bands

had been submitted for Wimax Forum certification since the forum’s labs

opened for business late last year (pdf). The forum is aiming to certify 100

products for interoperability by the end of this year, and 270 by 2010 – not

including CPE gear. The industry body, which lists almost 540 member

companies, promoted a walking booth tour of over 40 companies at the show

demonstrating Wimax equipment.

Cisco’s John Chambers predicted at the Mobile World Congress that by 2011,

WiMax will account for 10 to 15 percent of wireless traffic.

GSMA chairman Craig Ehrlich has been

openly critical of the Wimax business case,

describing it as too little, too late in the face

of escalating HSDPA rollouts and the coming

of LTE. Officials at China’s MII attacked

Wimax’s inclusion last October as an IMT-

2000 standard, seeing it as a rival to their homegrown TD-SCDMA

technology.

According to the GSM Association, about 80% of cellular users world-wide

use the GSM (Global System for Mobile communications) technology, or more

than 2.5 billion people. A total of 3.3 billion people — more than half the

world’s population — now use cell phones. Revenues, which totaled $125Bn

in 2007, are expected to reach $200Bn by 2011. Intel sees a $10 billion

mobile chip market by 2011.

[get this widget] Read More...

F O O T B A L L E R G E T S O W N 3 G M O B I L E T V C H A N N E L

Orange announced the launch of Frank TV, a mobile channel dedicated to

England and Chelsea star Frank Lampard. Frank TV will be available

exclusively to the 1.3 million Orange 3G customers on its mobile phone TV

service - Orange TV, and will be up alongside other Orange mobile TV

channels including BBC, Channel 4, Sky and FHM.

Frank TV features never-before-seen footage from Frank’s video diaries

which he filmed over the past two seasons, giving exclusive behind the

scenes access to Stamford Bridge, the Chelsea training ground, Frank’s

house, pets and much more. There are also special guest interviews with

Frank Lampard senior, Jamie Redknapp and Lawrence Dallaglio.

Jake Redford, Head of Mobile TV, Orange UK said: “We are delighted to

launch a dedicated channel to arguably one of the most committed and

professional midfielders in world football. Frank TV makes for great bite-size

viewing and provides our mobile TV viewers unique insight to the life behind

the footballer”.

[get this widget] Read More...

M A K I N G T H E C A S E F O R 3 G L T E - G L O B A L M O B I L E B R O A D B A N D

US : A new report published by the UMTS Forum predicts that LTE (Long

Term Evolution) - Global Mobile Broadband could generate total revenues of

€150 billion for operators by 2015.

The new report - titled Global Mobile Broadband: Market Potential for 3G LTE

- forecasts that smooth evolution from today’s investments in 3G UMTS

(WCDMA/HSPA) will kick-start a new wave of high-speed interactive services,

strengthening ARPU in many mobile markets.

Specifically, the report predicts that subscriptions to LTE - Global Mobile

Broadband networks will exceed 400 million by 2015, or double today's

number of WCDMA/HSPA customers. Furthermore, revenues from LTE -

Global Mobile Broadband will represent more than 15% of all mobile

revenues that are predicted to approach €1 trillion globally in 2015.

While it's expected that Western Europe and developed Asia will account for

the majority of LTE - Global Mobile Broadband customers, the report

forecasts strong uptake in developing markets by 2015.

While non-voice services currently represent just 10-15% of revenues in

developed markets, the study suggests that LTE - Global Mobile Broadband

will drive this proportion to 36% by 2015.

The report is based on original research conducted for the UMTS Forum by

Analysys Research (www.analysys.com), who modelled future demand for

global mobile broadband by extrapolating current market trends.

With technical specifications for LTE now stabilised within the Third

Generation Partnership Project (3GPP), it's an anticipated that the first LTE -

Global Mobile Broadband networks will be commercialised in 2010. Wide-

scale rollout is anticipated from 2011.

Building on current investments in the GSM/UMTS Evolution ‘family’ of 3GPP

systems, LTE - Global Mobile Broadband provides a smooth evolutionary path

to far higher data speeds and lower carriage costs with more efficient,

flexible use of operators' radio resources.

With more than 165 HSPA networks already commercialised or in

deployment, 3GPP’s significant global footprint will support a future mass

market for high-speed, high capacity services at significantly lower cost than

greenfield investment in other broadband wireless systems.

Enabled by SAE (Systems Architecture Evolution) that offers a 'flat' all-IP

architecture, LTE - Global Mobile Broadband also promises lower latency that

will support multiplayer gaming, social networking, high-quality

videoconferencing and a new generation of other real-time interactive

applications. The report also predicts that LTE - Global Mobile Broadband’s

low latency and reduced per-bit costs will drive the development of remote

monitoring and other machine-to-machine (M2M) applications.

"This new report demonstrates an extremely positive investment case for

LTE - Global Mobile Broadband", comments UMTS Forum Chairman Jean-

Pierre Bienaimé. "While it requires an upgrade of existing 3G infrastructures,

dramatically reduced opex costs compared with WCDMA and HSPA could see

operators break even as soon as 3-4 years after deploying LTE - Global

Mobile Broadband."

[get this widget] Read More...

L G V I E W T Y M O B I L E P H O N E E N A B L E S P L A Y B A C K V I D E O F R O M

T H E P C A N D T H E I N T E R N E T

LG and DivX announced their partnership to enable a high-quality consumer

media experience with the LG Viewty (Model: LG-KU990), a new 5.0 mega-

pixel digital camera phone available from LG Mobile.

The LG Viewty’s unprecedented multimedia capabilities reflect the extensive

partnership between LG Electronics and DivX. The LG Viewty enables

consumers to easily playback a wide range of DivX files from the PC on the

go or output to a TV monitor without converting to another format.

Consumers can also view DivX files from popular online video communities

such as Stage6.com at ten times the speed of WCDMA through the HSDPA

3.6 high speed internet access capability. DivX is a widely popular digital

media format that enables consumers to create, share and play back high-

quality video content across an ecosystem of platforms and devices.

The super sleek and stylish LG Viewty is the first in LG’s new line of high

technology handsets and boasts a number of ‘world first’ features never

seen before on a mobile handset, including 120 fps video recording as well

as unique camera functionality such as manual focus, image stabilizer and

handwriting recognition that makes editing easy on the Viewty’s 3-inch wide

LCD touch screen.

LG Viewty will go on sale from mid-October starting from Europe and on to

other regions

[get this widget]

Read More...

V O D A F O N E N E V E R F A I L H I G H A V A I L A B I L I T Y S E R V I C E F O R

B L A C K B E R R Y

Europe : Vodafone UK announced

that it has completed a deal with

Neverfail, a leading global

software company providing

affordable continuous availability

and disaster recovery solutions.

Vodafone will now offer business

customers a high availability and

disaster recovery service for

mobile email using the Neverfail

software.

In today’s business environment

access to email whilst on the move is a key requirement for many

organizations.

Losing email access, even for a short time, can have drastic consequences

for businesses. The Vodafone Neverfail High Availability Service for

BlackBerry will provide uninterrupted availability of BlackBerry services to

Vodafone business customers.

The Vodafone Neverfail High Availability Service for BlackBerry monitors the health of the entire email environment, including the server hardware, the network infrastructure, the application and the operating system. If any anomalies are identified, Neverfail will immediately take action to prevent loss of service. It will either automatically attempt to restart applications before they fail, switch over to a secondary server, or alert the IT staff so that no downtime or loss of service is experienced. Once the issue is resolved, they are automatically switched back to the main servers and neither users nor administrators are required to restart their applications.

“As market leader in the UK in providing BlackBerry services, it was important to be able to offer robust access to email. By adding Neverfail’s solution into our Managed Service portfolio, we can offer enormous service expertise to protect critical parts of our customers’ IT infrastructure,” said Curt Hopkins, Head of Enterprise Mobility Solutions, Vodafone UK. “Neverfail has an enviable reputation for protecting mission-critical systems with its continuous availability solutions and we have selected them as our preferred provider for high availability and disaster recovery for BlackBerry and email implementations.”“Vodafone as a company relies on continuous mobile access to email and we have also selected the Neverfail solution to use within our own organization,” continued Hopkins. “Having complete confidence that email will be available 24/7 365 days a year is a significant advantage as many key staff depend on access via Blackberry devices in order to fulfil their roles.”“Vodafone is well ahead of the general telecommunications market. Rather than just providing handsets and airtime minutes, Vodafone is offering strategic services, such as high availability, to support the entire BlackBerry platform,” said Richard Ruddlesden, EMEA Channel Director, Neverfail. “We are very pleased that Vodafone has selected us to offer its customers an exceptional communications experience that is the best in the industry.”Vodafone Managed Services will work in partnership with Neverfail in the UK to offer customers advanced capabilities such as continuous availability for mobile devices and communications solutions from RIM, MicrosoftÒ and IBMÒ LotusÒ NotesÒ.

[get this widget] Read More...

<< Newer Posts Older Posts >> Home

S E A R C H F R O M S I T E

wimaxcomnet.blogspot.com

B L O G A R C H I V E

► 09 (7)

Google Search

o ► Jun (7)

Intel Kills 2250 WiMax Chip

Saudi Mobily: $100M for Samsung WiMAX

Towards a REAL “4G” Standard

Virgin Mobile: Prepaid Data Plans

LTE & Mobile WiMAX Explained

Atlanta Gets Mobile WiMAX

Intel Research Day

▼ 08 (153)

o ► Jun (30)

Clearwire: We’re Gonna Be Big

WiMAX Open Patent Alliance

3.65GHz WiMAX Rolls Out

Zhone: Line-driven “N” MuniFi

Motorola: LTE for 700 & 2.6 GHz

Sprint: We’re the “3rd Pipe”

Battle for Britain

WiMax: East Meets West

3G iPhone Day

Computex 2008: Netbooks & WiMAX

AMD Rolls Out Mobile Platform

MXtv Makes Its Move

Broadband Wireless Saves Money: CTIA

Taipei WiMAX Expo

Canadian AWS Auction is On

The Next Big Thing: Small

Clearwire supports EC decision on WiMAX mobility

AT&T Beams Up HSUPA

Train Communications 2008

France Telecom and TeliaSonera would create giant ...

Tatung selects Alcatel-Lucent to supply WiMAX netw...

Camphone Compression & WiFi Mapping

Proxim APs Go High Security

WiMAX World EMEA

AT&T: We Like HSPA

WiMAX will enable mobile Web 2.0

Enforta expansion covers 55 million people

Google, Cable in $12B WiMAX Deal?

It’s Official: Sprint, Cable & Google Building WiM...

It’s Official: Sprint, Cable & Google Building WiM...

o ► May (13)

Intel: $500M for M-Taiwan

Qualcomm shows off MediaFLO Mobile TV

Towerstream Switches to Alvarion 3.65 GHz

3GPP Release 8 Features

WiMAX Roundup, Australia Unwired

Affordable Spectrum Analyzer

Forum Oxford Conference 2008

Mobile WiMAX Cooking- But Still in the Kitchen

More on LTE-Advanced

HSPA+ in Release-7 and Release-8

4G: War to End Wars

Motorola Mobile WiMAX in Thailand

Solectek 3.65 GHz WiMAX

o ► Apr (29)

o ► Mar (19)

o ▼ Feb (62)

Wimax transmit power calculation

Importance of the transmittig antenna gain for the...

WiMAX Receiver Sensitivity

Modulation

Frequency Planning

TTG, RTG

ASN Profiles

Calculation

Capacity Planning Discussion

Link Budget and Penetration

Recieve Noise Floor Question

Model Tuning Procedure

WiMax Spectrum Efficiency

Ultracompact 2G / 3G Dual-Mode RF Transceiver

Mobile World Conference Announcements

AWS Lights Up Texas

Mobile WiMAX at World Congress

Bare Nuckles in Barcelona: LTE Vrs WiMAX

Footballer Gets Own 3G Mobile TV Channel

Making the Case for 3G LTE - Global Mobile Broadba...

LG Viewty Mobile Phone Enables Playback Video from...

Vodafone Neverfail High Availability Service for B...

AT&T Announces HSUPA Cards

Comarco Adds High-Speed Uplink Packet Access (HSUP...

Industrial Design Consultancy Unveils a Whole New ...

SP4T Antenna Tuning Switch for GSM /EDGE / WCDMA a...

T-Mobile Launches 3G HSDPA MDA Vario III

Ericsson to Deliver 3G WCDMA / HSPA Network to Vim...

ZTE Launches First SDR Base Station

MLL Telecom Makes Successful Bid in UK Wireless Sp...

HTC Unveils Q4 2007 3G Smartphone Device Line-up

Ofcom Proposes Action Against O2 to Meet 3G Rollou...

Nokia Nseries Users Access to 3G Mobile Videos On-...

Google's Android Software Platform Makes Debut

Up to Ten Times Faster Mobile Broadband Data Rates...

Satellite and 3G Cellular Networks for Universal I...

Seamless Video Service Connecting Video in RSS Fee...

UMA to Support Upcoming 3G Dual-Mode Handset and F...

Plasma Antennas

HP UMPC: Easy Come, Easy Go

T-Mobile Expands Hotspot@Home

Xohm: Open, Open, Open

Google + SingTel = Unity Submarine Fiber

How to beat Google (and why Microsoft + Yahoo prob...

Mobile Device of the Year, 2007

Clearwire Mobile WiMax in Portland

Smartphones Increasing Popular

WiMAX MIMO Antennas

OFDM.. enabling New generation communication stand...

WiMAX MAC Layer

Mobile WiMAX: TDD Now, FDD Soon?

Fujitsu & Airspan Jointly Market Mobile WiMAX

On WiMax Cost and performance

Motorola Adds WiMAX Clients

Modules for wireless applications

Alvarion Introduces AAS Mobile WiMAX

Convolutional codes and The Viterbi algorithm

Mobile Security

WiMAX Architecture

Why QoS?

On WiMax MAC layer

IDF Report 2: WiMAX, the Crown Jewel