User Speed Rates of GSM Technologies

Tremendous achievements of wireless world is providing more enjoyable lifestyle to us. Especially,  watching HD movies via stream is edge corner now for end users like me.

Mobile trend is growing rapidly. Following figure shows the interesting statical result from JohnHughes blog.

 Think about it, you are living with your search tool just in your pocket. You do not need to use any cable,device connection etc and you can reach internet very easly with sufficient speed generally. 

Because of the importance of smart phones, we are facing with enhancing wireless mobile telecommunication technologies day by day.

We are planning to explain actual speed rates of each technologies by starting with GPRS technologies briefly.
 

 2G technologies could not reach the Mbps speed rates unfortunately except EGPRS-2. EDGE has 237 kpbs DL speed theoretically. it varies between 120Kbps to 384Kbps practically for per user. Other name of EDGE is 2.75G.

With the introducing WCDMA, we have met superior speed rates. above picture demonstrates the performances of 3G and 4G techs.

Thi biggest issue for high speed wireless networks is the lack of bandwidth. We can say it also as range of usable frequencies. So we put following pictures from speedtest.net to compare pratical and theoretical results for user speed rates.

4G VERIZON USA
  

4G AVUSTRALIA

 4G TMO  EURO

Note: I checked the users fro this test and one user speed rate was 980.92 Mb/s within 188 total tests . I subtracted that one and recalculated the speed test and it was ~10Mbps like in Verizon USA.
 
Speed of Wireless techs has a lot of obstacles like total user, location and velocity, many type of interferences, total users  etc. But we can say , humanity has got very good achievements  about it during this decade and we can easily say that 4G is really great even though it can not be able to reach to wireline speeds at least these years.
 

REFERENCES
http://www.gsma.com/ 
http://autoblog.johnhughes.com.au 
http://www.speedguide.net/faq_in_q.php?qid=366 
http://www.radio-electronics.com/ 
http://www.speedtest.net
http://www.wisegeek.com/what-is-evdo.htm 
http://www.zdnet.com 

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LTE Security

Based mobile networks supporting a rapidly growing number of computationally powerful devices  such as  smartphones and tablets is changing the mobile security landscape and will fundamentally 
change the way we perceive and deal with mobile security. Mobile networks are becoming more

pervasive, more widely used, and more deeply connected to other network.

 

Devices and the core network are most heavily targeted parts of the mobile network.



Basicaly we can separate the security as for subscriber authentication and attacking to mobile to core devices.

Authentication procedures use very complex algorithms, personally it is not a big threat for mobile operators. By the way, we are starting with authentication very briefly

Authentication
   
Operators like Verizon in USA are using 3GPP  SNOW 3G Specification for Confidentiality and Integrity Algorithms UEA2 & UIA2, 128-EEA1 & 128-EIA1.
  
SIM means Subscriber Identity Module (SIM). All wireless mobile technologies have different type of SIM cards. For example,USIM is using in 3G Sim cards with Milenage Authentication. Before 3G, we were using A3 and A8 authentication algorithms. 

A3/A8 had some weakness, that enable attackers to break the encryption key in less than one second, breaching customer’s identity and allowing billing fraud and  putting telecom operators in a serious legal situation.

The older SIM cards are not compatible and may not be used in LTE.

Security the keys used are128 bits in LTE.

  
Important: Mobile Phone has to support SNOW 3G algorithm.

 Securing LTE Backhaul

 

Most attacks will be directed at the mobile core network, external sites, and subscriber data and devices, but they can also be more limited in scope and target a single eNB or a group of nearby eNBs (eNB identity spoofing and impersonation).Tampering, traffic hijacking, eavesdropping, DoS,compromised control data,unauthorized access,and loss of accountability of the control plane are the biggest threats to the core network.

To secure traffic,as an my personal opinions based on my researches an IPsec tunnel has to be established between the eNB,and the MME, SGW and O&M in the core network over the user,control and management plane, and terminated at a SEG (security gateways) that sits at the border of the trusted area.

REFERENCES
http://www.mcit.gov.sa/nr/rdonlyres/d762830c-fbe7-4b36-aafc-780cfbafc92c/0/paper36.pdf 
http://www.3gpp.org/ftp/Information/presentations/presentations_2011/2011_05_Bangalore/DZBangalore290511.pdf
http://support.verizonwireless.com/faqs/VZAccess/4g_sim_card.html
http://security.stackexchange.com/questions/21395/how-is-4g-lte-encrypted
http://www.etsi.org/index.php/services/security-algorithms/3gpp-algorithms
http://www.authentec.com/Products/EmbeddedSecurity/SemiconductorIP/3G4GLTECiphers.aspx
http://itmf.uga.edu/minutes/2011-03-03/verizon_presentation.pdf
http://www.embedded.com/electronics-products/electronic-product-reviews/ip-eda-products/4212398/Elliptic-launches-security-processing-engine-for-4G-wireless-markets
http://www.radio-electronics.com/info/cellulartelecomms/lte-long-term-evolution/lte-security-authentication.php
http://www.sciencedirect.com/science/article/pii/S0140366410003105
http://www.slideshare.net/aliirfan04/lte-security-overview
http://www.f5.com/pdf/white-papers/wireless-security-lte-networks-wp.pdf
http://internetandwebsecurity.blogspot.com/2010/10/radisys-introduces-carrier-grade-lte.html
http://www.tellabs.com/resources/papers/tlab_ipsec_wp.pdf

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What is going to be happen with LTE?

Following figure shows the simplified general view of wireless telephone technologies

Journey of Wireless mobile technologies started with 2G in 1980s ( we are not interested in 1G which was using  analog telecommunications standards like AMPS in North America, TACS, NMT etc in other regions and before 1G breakthroughs.)
We have introduced with GPRS in the beginning of 2000's  and few years later EDGE popped up.
After 2003, we have met with CDMA based 3G networks. And now( not exactly but not so much time occured by the way) our new buddy is LTE.

 Above picture indicates the radio interface multiplexing enhancement. LTE is using OFDMA for dowlink and SC-FDMA for uplink.

 OFDMA simply provides;
 Spectral efficiency 
 Resistance to multipath interface
 

 




















MIMO
The multiple input, multiple output antenna or better known as the Mimo antenna technology uses multiple radios to transfer more data at the same time and it is really very important innovation.  

 All-IP Based Network Architecture 

The above figure shows gateway solution, offers one device including MME and Serving/PDN Gateway in one place. This is great enhancement for operators. So that, they will be able to update their  network without paying huge money. This upgrade provides also higher network performance, efficient IP routing and latency reducing. 
All-IP, Simplier, Flatter Network = Reduced OPEX & CAPEX
This improves the quality of experience, so let's imagine, it will give us better satisfaction for real time  applications of communication like VoiP.

 As a result,

LTE will have a large impact on application performance

and network capacity

LTE can be introduced in a progressive, scalable, and 

cost effective way

REFERENCES
http://en.wikipedia.org/wiki
http://www.3gpp.org/LTE
http://nortel.com
http://www.mobileisgood.com/ofdm.php
http://www.intel.com/support/wireless/sb/cs-025345.htm
http://www.wildcatalliance.org/the-mimo-antenna-and-its-pros.htm
http://www.digikey.com/us/en/techzone/wireless/resources/articles/wireless-mimo-driving-rf-challenges.html
http://www.iphase.com/products/lte_about.cfm
http://gsmcommunications.blogspot.com/2011_04_01_archive.html

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What are the benefits of LTE?

Frankly, i not volunteer to dig into benefits of 4G for me. Why? maybe i do not like the new things in tech world. Right ?  Of course not. I really want bigger internet speed for my mobile phone to be able to watch HD movies from streamline. Based on Motorola reports "75% of users watch online video*
YouTube = 27% of internet traffic". I bet that people's data traffic will increase meteorically in near future.

But what about budget? I recently purchased new smart phone and it is not supporting 4G.  By the way, we  met with 3G few years ago and I think 4G will not reach here within at least several years.

My phone is not following smart phones listed below unfortunately which are Iphone5,  Samsung Galaxy S3 LTE , Samsung Galaxy Note 2 LTE , Nokia Lumia 820 and 920 , Huawei Ascend P1 LTE and so on. ( I saw pictures about Samsung Galaxy S4 and Samsung Galaxy note 3 in news this week)

On the other hand, if we forget about the bugdet and money things LTE has a following benefits for end-users like me :)

1) It can be an alternative for your wireline DSL internet at your home.
If your are not using Fiber-ADSL at your home. This is true. On the other hand, no body is expecting that the more faster Wireless data download speed than Wireline of course.

2) Better gaming, video chat... experience. 
We are expecting better success that 3G about this case thanks to LTE's lower mobile wireless latency. Sometimes we are facing bad situations even when we were using Wi-Fi.

3) Better Security. LTE uses Symmetric Key Cryptography
UMTS or WCDMA 3G is using Milenage paramethers for authentication. And now, we see much more better security with introducing Symmetric Key Cryptography.

4) Very nice pictures with advanced resolution.
Since LTE will be able to support higher data traffic, this will introduce us new mobile phones with high and/or ultra-high quality pictures.

5) Competition
I hope this theory is correct here. We are just hoping this result. It is still expensive in GSM operators and you should select tariffs with quota if you do not want to pay much in Turkey. (I hope USA has better prices :) )

We saw the full side of the water glass. Of course LTE will bring extra cost for end-users and operators. From the operator perspective , at least they have to add extra antennas. And also one interesting theory is signalling storm problem. I did not check it thoroughly but seems interesting.If you want to get more info about  you can visit the web page www.seven.com.

Thanks and see you in next blog

REFERANCES:
http://www.phones4u.co.uk/4g/
http://www.digitaltrends.com/mobile/smartphone-buyers-dont-care-about-4g-yet-study-shows/ 
http://www.netmanias.com/bbs/view.php?id=cshareforum_mobile&no=47
http://www.seven.com/press_releases/2012/wireless_network_worst_case_scenario.php
http://www.sonlte.com/2012/03/12/my-top-5-end-user-benefits-with-lte/
http://www.fiercetelecom.com
www.motorola.com

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Which modulation types are being used in GSM and it's successors

If we quit pre-GSM wireless technologies, we can specify the mobile technologies as followings:

GSM
An open, digital cellular technology used for transmitting mobile voice and data services 
GPRS

A very widely deployed wireless data service, available now with most GSM networks

EDGE

GSM Evolution (EDGE) technology provides up to three times the data capacity of GPRS 
WCDMA or 3G

The air interface for one of the International Telecommunications Union’s family of third-generation (3G) mobile communications systems.
HSPA
 The set of technologies that enables operators to upgrade their existing 3G/WCDMA networks to carry more traffic and at faster speeds.

LTE
Designed to be backwards-compatible with GSM and HSPA, Long Term Evolution uses the OFDMA air interface, in combination with other technologies, to offer high throughput speeds and high capacity.

Wireless or not we are using 2 types of signal. One of them is carrier signal and the other one is data signal.

  
We can consider this sinus wave as our carrier signal as an example.

And let's consider above figure is our data signal.

To be able carry our data, we have to use carrier signal in order to send it to long distances.
Let's put all together in PSK modulation

                                     

Note: we need only one carrier for PSK. Some of the modulation types requires  2 different carrier signals like FSK. 


Modulation may be done by varying the amplitude,phase, or frequency of a high frequency carrier
inaccordance with the amplitude of the message signal. 

Main goal of enhanging modulation is just inreasing the number of bits carried by Hertz or bandwidth.
Now, let's briefly see the modulation types for GSM technologies:

GSM GPRS uses GMSK type modulation.

Note: It is common way to explain modulation types by using polar graph. The letter I means a carrier 'In Phase' with the carrier signal. And in the letter Q means 'Quadrature' (or perpendicular). Do not worry you can consider I and Q as X and Y axixes for angle. Also please see the link for further information regarding symbol and quantization http://en.wikipedia.org/wiki/Quantization_%28signal_processing%29

EDGE uses  8PSK modulation

UMTS and WCDMA
Regarding UMTS Release 99 it was QPSK.  After 3GPP Release 7 introduced 64QAM modulation for HSDPA and 16QAM for EUL

The advantage of using QAM is that it is a higher order form of modulation and as a result it is able to carry more bits of information per symbol. By selecting a higher order format of QAM, the data rate of a link can be increased.
The table below gives a summary of the bit rates of different forms of QAM and PSK.

LTE
LTE stands for Long Term Evalution and really trembles me as my expectations is very high for it.
Actualy my operator is using UMTS based tech in Istanbul and it is sufficient to watch something from youtube. (maybewe do not have so much data traffic because of unwanted bills :) )
Regarding 3GPP spects  we will introduce with 128 QAM


Now, it is enough to talk about modulation to prevent to go into deeper :)
See you in next blog. Please do not hesitate me to contact if you have suggestions, reccomendations or questions.
Have a great day.


REFERANCES
http://www.gsma.com/aboutus/gsm-technology
http://www.exaltcom.com/
http://www.ilmondodelletelecomunicazioni.it/argomento.php?id_lezione=43&id_capitolo=287
http://biosonicstelemetry.com/resources.php
Prof. Robert Webber from following link:
http://www.youtube.com/watch?v=-_TWtJsgzlw&NR=1&feature=endscreen
http://www.telecomhall.com/what-is-modulation.aspx
http://staff.neu.edu.tr/~fahri/mobile_L7.pdf
http://wireless.arcada.fi/MOBWI/material/CN_4_4.html
http://mobile-telecom-networks.com/umts/general/17-modulation-schemes-used-in-umts
http://www.radio-electronics.com/info/rf-technology-design/pm-phase-modulation
http://www.3gpp.org/ftp/Specs/html-info/36912.htm

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Indispensable Thing of Wireless World: MODULATION

Modulation, we are facing this thing every single day if we are listening radio ,television or using mobile phone.
I will try to explain this to you in simply way as it may seem simple, the transmission and reception of information is quite complex, considering the many possibilities and scenarios where this may occur.
We will not go deep into advanced mathematical operations like Fourier Transform,Impulse Functions or Shannon theorem etc. Our goal is endearing modulation to our valuable followers.

So let's start it;

If you are not talking with your friend in close distance, so you need a device to be able to hear his/her voice.
In history, we had used smoke or pigeon etc instead of voice. Now we can use more smart devices like mobile phone. Let's consider our voice is data signal and we want to carry it to very long distances so we have to use high frequency carrier as low-frequencies can not carry this data to long distances.
Why we have to use carrier signal instead of our voice? reason will send us to the very important result. Which is modulation. Basically from our school years, electro-magnetic waves theory will answer this question.
Voice frequency is ~3 kHz. It means that we need height of antenna equal to 100 km! This is practically impossible! However we can reduce its height by l/2, l/4, l/8 or up to l/16. But even if we reduce it to l/16, it becomes 6.2km, which is still impossible!
To be able to use proper antennas we need modulation and we need to do some processes in like following figure.

So we need to carry our signal by modulating it. but after receiving we need to do reverse process which is called demodulation.

More concepts ...

• Modulation : changing the characteristics of the signal being transmitted.
• Demodulation , the reverse process of modulation.
  

Before our voice is to be transmitted, it must be converted. For this reason, there are digital devices that convert analog voice through a process of sampling and quantization.
In GSM, we are generally using PCM (Pulse Code Modulation) shown in above. Between the maximum amplitude and minimum signal levels are set 16 (0 to 15), and these are encoded as binary numbers (0000, 0001, ..., 1111).

We can classify the modulation  types as ;

• Frequency
• Amplitude
• Phase
   

We  will try to explain modulation types in next blog especially in GSM perspective.Thanks and please do not hesitate to share your ideas, questions  and comments anytime.

You can watch the followings videos to see modulation types in practice

 

REFERANCES:

http://www.telecomhall.com/what-is-modulation.aspx

http://en.wikipedia.org/

http://www.kapsch.net/

http://www.nortel.com/
http://www.uslanmam.com
http://vsagar.com/2011/12/12/modulation-transmit-signals-fundamentals-modulation-demodulation/ 

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Mobile Spy

Web includes a lot of  fake, scam sites. So how can we be sure about security if we want to find very specific thing to buy like spy applications for your mobile phone.

So we need to do very good investigation.We checked the internet for reliable web site to be able to buy spy software.

As an example; The web page of mobile spy is very interesting, mentioned software can do many spy actions regarding their web page claim. I looked into internet and saw numerous pages . Following excerpt is  from mobile spy web page:

NewYork Times
Check out how writer Roy Furchgott described
Mobile Spy in The New York Times...

"Once installed on a phone, Mobile Spy remains hidden but logs calls and texts to Mobile Spy's server. Then the snoop can log in and see a complete record of incoming and outgoing calls, the time and duration of the calls, and read text messages both sent and received."

I list the most popular ones below.
If you would like to get more information, you can visit their web page..
Based on my searches, Spybubble seems more easier to use than other spy apps. 



 
 

 

 



REFERENCES
http://sorbana.net/konu/spybubble/   *It is Turkish
http://www.mireview.com/
http://eyeportal.blogspot.com/2012/02/en-iyi-cep-telefonu-dinleme-casus.html  
http://www.mobile-spy.com/
http://www.spybubble.com/
http://www.mspy.com/?gclid=CLCv3dXBi7YCFUWS3godJkUAlw
http://www.stealthgenie.com/
http://www.spectorsoft.com/

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