MOBILE NETWORK BASICS

Cellular Network Basics: 

• There are any types of cellular services, before developing into details focus on basics ( helps navigate the "acronym soup")
• Cellular network is radio based technology, radio waves are electromagnetic waves that antenna propagate.
• Most of signals are in the range of 850 MHz, 900 MHz,1800 MHz and 1900MHz frequency band.

Cell phone operating frequency range

Cellular Network:

• Base stations transmit to and receive from mobiles at the assigned spectrum ( Multiple base stations use the same spectrum).
• The service area of each base stations is called a cell.    
• Each mobile terminal is typically served by the closest base stations.    
• Handoff when terminal move.
  
  
  
  
  
  

Cellular Network Generations:

• It is useful to think of cellular telephony in terms of generation 

      -  0G : Briefcase size mobile radio telephones
      - 1G : Analog cellular telephony.
      - 2G : Digital cellular telephony.
      - 3G : High speed digital cellular telephony.
      - 4G : IP based " anytime any where " voice data and multimedia telephony                    at faster data rate than 3G ( currently 4G is being used )

Generation of cellular network

GSM(Global System for Mobile):

• Concurrent development in USA and Europe in the year of 1980.
• The European system was called GSM deployed in the year of 1990.
• In GSM technology the voice frequency range 3.1 KHz.
• SMS (Short Message Service) was introduced first, by GSM technology.
• GSM mainly provides IP based general packet radio service (GPRS) where data transmission rate up to 114 kbps.
• GPRS provides " always on" internet access and MMS (Multimedia messaging Service).

Subscriber Identity Module (SIM):

• It is small smart card.

• 

  SIM card

  Encryption codes is needed to identify the subscriber.
• Subscriber's own information (telephone directory).
• Can also be used in other systems besides GSM, e.g, some WLAN access points accept SIM based user authentication.

Base Station Subsystem(BSS):

BSS with channel

 

Base Station Controller(BSC):

• Controls the channel (time slot) allocation implemented by the BTSes.
• Manage the handovers within BSS area.

Base Transceiver System :

• Controls several transmitters
• Each transmitter has 8 time slots, some used for signaling, on a specific frequency.

Mobile Switching Center (MSC):

Overview of MSC

•  An typical telephony exchange (ISDN excchabge ) which supports mobile communications 
• Visitor Location Register(VLR) 

       - A database, part of the MSC

       - Contains the location of the active Mobile Stations.

        

Home Location Register(HLR):

• Contains the subscriber identification information authentication information in Authentication Center(AuC).

 

Home Location Register

Equipment Identity Register(EIR):

International mobile station Equipment Identity (IMEI) codes used for trace the stolen phones.

Roaming: 

When a mobile station enters another operators network, it can be allow to use the service of the particular network.

• Operator to Operator agreement and contracts.
• Sometimes it may be higher billing.

Roaming

3G Overview:

• 3G is created by Telecommunication Standardization Sector of the International Telecommunications Union (ITU -T).
• Audio and Video can be transferred through 3G network. 

3.5 G: 

• High speed packet access(HSPA) is improved the performance of 3.5G

3.5 G Features :

• Adaptive Modulation and Coding Schemes
• Very fast scheduling
• Enhanced air interface

4G(LTE):

• LTE stands for Long-Term Evolution 
• LTE is the next generation mobile broadband technology 
• Data rate nearly equals to 100 Mbps
• Optimize for AII-IP traffic
• Based on UMTS  3G technology 

Advantages of LTE:

• High network throughput
• Low latency 
• Plug and Play architecture 
• Faster download / upload data
• Increase the response for application
• Multi input, multi output facility 

LTE Vs VoLTE: