2G, 3G & 4G brief architecture and comparision

History of Mobile Networks

AMPS (1G):-The first smartphones used analog radio waves to communicate with the base stations
was the Advanced Mobile Phone System, or AMPS in U.S.
GSM (2G):-Digital cellular networks came onto the scene in the 1990s called Global System for Mobile communications, or GSM, also brought us the text message.
GPRS (2G):-General Packet Radio Service is the first commercial mobile data service worthy of the
name, sending data at about 14Kbps and receiving it at roughly 40Kbps.
EDGE (2G):-Enhanced Data rates for GSM Evolution, EDGE pushed speeds up to around 135Kbps.
UMTS (3G):-The Universal Mobile Telecommunications system was boasting speeds well over 200Kbps
HSDPA(High-Speed Down-link Packet Access):-It is based on the 3G network and an enhancement to 3G. Thus has a faster speed, download speed can be up to 14Mbps. HSDPA is sometimes called 3.5G.
HSPA+(Evolved High-Speed Packet Access):-HSPA+ is an evolution HSPA(HSDPA&HSUPA). It is a 4G technology that allows download at a rate of up to 168Mbps. It is also known as 3.75G
4G LTE(Long Term Evolution):-LTE is a 4G communication standard that supports HD video
streaming, download speed as high as 299.6Mbps.

GPRS(114Kbps) < EGDE(368Kbps) < 3G(3.1Mbps) < HSDPA(14Mbps) <
HSPA+(168Mbps) < 4G/LTE(299.6Mbps)

GSM {2G} Architecture

Mobile Station{MS}:- MS communicate over Um Interface to Base Station . It contain SIM, Phone book. IT is portable.
Base Station Subsystem{BSS}:- BSS consists of a Base Station Controller{BSC} and one or more Base Transceiver Station {BTS}. BTS defines a single cell and a link to BSC. BSC is responsible for reserving RF manages Hand off of Mobile Unit from one cell to other cell.
Network Subsystem{NSS}:- NS provides a link between cellular network and Public Networks .
NS is responsible for control handoffs between Cell in different BSS, Authenticates users an validates accounts, Enables worldwide roaming of mobile user
NS has following components:-
1:-Home location Resister{HLR}:- database is used to store info about each subscriber that belong to it.
2. Visitor Location Register{VLR}:- Database is used to determine the position of Subscriber in which the subscriber entered.
3. Authentication center{AuC}:-. Database is used for authentication activities of system.
4:-Equipment Identity Register{EIR}:- Database keeps track of the type of equipment

 Why 3G over 2G???

• While 2G networks focus primarily on voice communications, text messaging and simple web browsing, 3G devices offer near-broadband speeds for web browsing and multimedia integration.

•  Function:-The main function of 2G technology is the transmission of information via voice signals while that of 3G technologies is data transfer via video conferencing, MMS etc.

• Features:- The features like mobile TV, video transfers and GPS systems are the additional features of 3G technology that are not available with 2G technologies.

• Speed:- The downloading and uploading speeds available in 2G technologies are up to 236 Kbps. While in 3G technology the downloading and uploading speeds are up to 21 Mbps and 5.7 Mbps respectively

• Cost:- The license fee to be paid for 3G network is much higher as compared to 2G networks. The network construction and maintenance of 3G is much costlier than 2G networks. 

What is 3G???

• 3G, short form of third generation, is the third generation of mobile telecommunications technology

• In India 3G operated on 2100 MHz Band. World wide it operated on any one of 850, 900 and 1900 or 2100 MHz bands.

• The original 3G UMTS / W-CDMA standard provided a maximum download speed of 384 kbps.

• HSPA offers speeds of 14.4 Mbit/s down and 5.76 MBit/s up.

• HSPA+ provides data rates up to 42 Mbps in the downlink and 11 Mbps in the uplink. 
  

UMTS{3G} Architecture

A Universal Mobile Telecommunications System {UMTS} network consist of three interacting domains; Core Network(CN), UMTS Terrestrial Radio Access Network(UTRAN) and User Equipment (UE).

The Radio Network Subsystem comprises two main components:
1.NodeB:- Act same as BTS in GSM. It contains the transmitter and receiver to communicate with the UEs within the cell
2. Radio Network Controller{RNC}:- The RNC controls the operation of multiple NodeBs, managing resources such as allocating capacity for data calls, and providing critical signaling such as call set-up, plus switching and traffic routing functionality.

UMTS core network contain two main area:- Circuit switched element, Packet switched element

Circuit switched elements:-The circuit switched elements of the UMTS core network architecture include the following network entities:
Mobile switching center (MSC):- This is essentially the same as that within GSM, and it manages the circuit switched calls under way.
Gateway MSC (GMSC):- This is effectively the interface to the external networks.

Packet switched elements
 The packet switched elements of the UMTS core network architecture include the following network entities:
Serving GPRS Support Node (SGSN):- SGSN provide number of functions like…mobility management, Session management, Interaction with other area of networks, Billing
Gateway GPRS Support Node (GGSN):- is the central element within the UMTS packet switched network. It handles inter-working between the UMTS packet switched network and external packet switched network
Shared elements
  The shared elements of the UMTS core network architecture include the following network entities:
1:-Home location Resister{HLR}:- database is used to store info about each subscriber that belong to it.
2. Authentication center{AuC}:- Database is used for authentication activities of system.
3:-Equipment Identity Register{EIR}:- Database keeps track of the type of equipment that exists at the mobile station .



                                                  Why 4G over 3G??????
Improved data capacity:
With 3G LTE offering data download rates of 100 Mbps, and the focus of the system being on mobile broadband. In 4G device act as a mobile broadband and it support upto 1 Gbps link.
All IP architecture:
 When 3G was first developed, voice was still carried as circuit switched data. In 4G all communication is based on IP, whether it is voice call, video call or data.
Reduced latency:
 With increased levels of interaction being required and much faster responses, the new SAE concepts have been evolved to ensure that the levels of latency have been reduced to around 10 ms.
Reduced OPEX and CAPEX:
 A key element for any operator is to reduce costs. It is therefore essential that any new design reduces both the capital expenditure (CAPEX)and the operational expenditure (OPEX). In 3G, there are so many separate equipment which are logically and physically different and also have some specific work. But is 4G size of equipment reduced drastically. Logically they are different but physically they are integrated as one. So now, this reduces the set-up and commissioning time
 

                                                        What is 4G{LTE}???

• An acronym for Long Term Evolution, LTE is a 4G.

• It provide up to 10x the speeds of 3G networks.

• 4G technologies are designed to provide all communication IP-based.

• It provide voice, data and multimedia streaming at speeds of at least 100 Mbit per second and up to as fast as 1 GBit per second.

• 2x2 MIMO{410, 615} and 4x4 MIMO{805} are used in devices.

 

LTE Architecture

Long term evaluation is known as LTE. LTE contain mainly 3 parts:-

1. User Equipment{UE} 2. EUTRAN 3.Core Network{CN}
Core Network{CN}:- The core network has overall control of the UE and establishment of the bearers.
It contain following logical nodes:-
1.Serving Gateway:- All user IP packets transfer through S-GW. It retains information about UE while it is idle. It serve as mobility anchor when UE move for internetworking with other technology like UMTS or 2G.
2.MME:- It control node that process signaling between the UE and the CN. It serve function related to bearer management and function related to connection management.
3.Policy control and charging rules functions{PCRF}:- It control flow based charging functionality.
4.Home Subscriber server{HSS}:- database contain SIM information for its network.
5.PDN Gateway{PDN-GW}:- allocate IP to user and provide quality of service .

EUTRAN:- It contain eNodeB. eNodeB is responsible for all radio related functionality. All communication in between EUTRAN and EPS is IP based. eNodeB connected to each other with X2 interface, with EPC with S1 interface, with MME to S1-MME interface and with S-GW with S1-U interface.

It is responsible for
1.Radio resource management{RRM}:- This covers all functions related to the radio bearers, such
as radio bearer control, radio admission control, radio mobility control, scheduling and dynamic
allocation of resources to UEs in both uplink and downlink
2.Header Compression – This helps to ensure efficient use of the radio interface by compressing
the IP packet headers that could otherwise represent a significant overhead, especially for small
packets such as VoIP.
3.Security – All data sent over the radio interface is encrypted.
4.Connectivity to the EPC – This consists of the signaling toward MME and the bearer path toward the S-GW.
UE:-user equipment (UE) is any device used directly by an end-user to communicate. It can be a hand-held telephone, a laptop computer equipped with a mobile broadband adapter, or any other device. It connects to the eNodeB