What is changed after introducing with microSIM?

 Hello everybody, after a half month, finally our new blog pops up. Because of a lot of stuff to handle, I could not be here. Anyway, I decided to write something about SIM cards. Like I said from prior blogs our goal is share information with people with simply and useful practically so we will not go into detail and get your feedback with questions, suggestions.  So that, we can enhance our knowledge.

What is SIM?

SIM means Subscriber Identity Module. SIM card is smart card, it holds subscriber information like IMSI, MSISDN ,SMS server information and memory for contact info , sms . SIM card also keeps authentication parameters like Sres, Op/Opc, Ki etc .

The European Telecommunications Standards Institute (ETSI), which sets the standards for SIM cards, tells us that except for the size of the plastic around the chip, micro SIM cards are identical to the SIM cards we normally find in phones.

There are two type SIM cards;
The first basic families are SIM/USIM (for 2G and some 3G networks), the RUIMs (for CDMA networks) and UICCs (for 3G and LTE networks).

USIM:Universal SIM   RUIM: Removable User Identity Module  UICC: Universal Integrated Circuit Card

Why do I need to use SIM card?

SIM card is our ID in mobile phone network. To be able to get into this network we need authentication. So this very small smart card holds all authentication parameters. Regarding GSM technology it uses different type Authentication algorithms like Milenage in UMTS and Snow-3G in LTE.

SIM Card capacity:

Each product family is then defined by the size of the memory made available to the telecom operator. They are usually 64KB, 128KB, 256KB, 500KB, 700KB, etc.  But i did not see any SIM card in real World with capacity 700kb for gsm.

 Which phones are using microSim?

Lates phones are Samsung Galaxy S4, BlackBerry Q10, LG Optimus G LTE 4G, HTC One 4G, Sony Xperia Z, Motorola RAZR i and Nokia Lumia 520.

Why microsim?
I could not find a good answer for it because of vendor requests. Physical Size of chip in both SIM and MicroSim are same.  Maybe it is for preventing unlocking but it is cutting to new microSIM shape with some special tools. So this theory is not valid at least in Turkey. If someone knows the actual reason please enlighten me J

How can I program SIM card

First you have to find SIM card reader. Some of them are Orga and Gemalto. But do not forget you cannot find any tool that can reach the files where authentication parameters are storing.

 Does SIM have special applications on it?

We call it VAS; it stands for Value Added Services. A value-added service (VAS) is a telecommunications industry term for non-core services or, in short, all services beyond standard voice calls. It was SMS, MMS and such kind of basic things in the past. After changing customer expectations it is changed to more advanced applications like Push-To-Talk, Call conferencing, SMS auto reply, Weather information, voicemail and so on. Since VAS is not simple thing, I am planning to explain VAS in future.

 

Sources:

http://www.eservglobal.com/solutions/value-added-services

http://cellplan4u.com/store/product_info.php?products_id=41

http://apcmag.com/card-tricks-why-apple-put-a-microsim-into-the-ipad.htm

http://asia.cnet.com/whats-the-big-deal-about-the-microsim-62200148.htm

 

 

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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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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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