GSM NETWORK

             GSM Network Architecture

The Global System for Mobile Communication commonly referred to as GSM network comprises of Base Station Subsystem, which is the radio access part and the Network Switching Subsystem which forms the core part.The Base Station Subsystem comprises of the Base Station Transceiver and Base Station Controller while Network Switching Subsystem comprises of Mobile Switching Center and other network elements attached to it like the Visitor Location Register. 

 

Mobile Station (MS); Inside the mobile phone lies  RF chip, DSP, SIM. The SIM contain all information related to the services subscribed by the subscriber and the information regarding the encryption.

Base Station Subsystem (BSS); The  Base Station Subsystem handles all radio-related functionality providing the air-interface connection the mobile station to the network. The subsystem consists of The Base Transceiver Station  (BTS) and The Base Station Controller (BSC).The BTS provides radio services to areas sectorised into cells and a group of BTS are interfaced with one BSC which is responsible for frequency allocation and handovers between BTS in the areas covered by the BSS.

Network Switching Subsystem. (NSS) This subsystem performs switching functions and acts as interface between the cellular and circuit switched networks.Handles all call processing functionalities and handovers between BSCs besides security and other functions like authentication.  The NSS, also referred to as the core network  houses some data base elements like . 

• HLR- Home location Register, data base holding subscriber information 
• VLR- Visitor Location Register, database for storing information regarding subscribers that visited   the area serviced by the VLR
• AUC   Authentication Center-  AUC is responsible for  the generation of authentication triplet  which is passed onto the VLR for authenticating subscribers .
• EIR Equipment Identity Register- Keeps track of the identity of the mobile station attached to the   network.

As can be seen from the diagram above, there are standard interfaces between Subsystems and the elements in the subsystem. These interface are explained below with the help of the protocols that exist between them.

Interfaces between Subsystems are;The air interface between the mobile station and the Base Station Subsystem and the A interface between the Base Station Subsystem and the Network Switching Subsystem.

Interfaces and Protocols

 

Interfaces
Um    Air interface between MS and BTS
Abis  Interface between BTS and BSC
A       Interface between BSC and MSC
B       Interface between MSC and VLR
C       Interface between MSC and HLR
D       Interface between HLR and VLR
E       Interface between MSC and MSC/GMSC
F       Interface between MSC and EIR
G       Interface between VLR and VLR
H       Interface between HLR and AUC

Protocols
LAPDm  Link Access Protocol Dm Channel
LAPD     Link Access protocol D channel
BSSAP   BSS Application Part
MAP       Mobile Application Part
ISUP       ISDN User Part
TUP        Telephone User part

Moore’s Law; Will transistors eventually reach the limits of miniaturization at atomic level?

Moore’s Law, a computing term which is used in the semiconductor industry to help in long term planning as well as research and development in the industry was first coined by Gordon E. Moore, the co-founder of Intel Corporation. The law, which is prediction or rather an observation, states that the number of transistors per square inch on integrated circuits had doubled every year since the integrated circuit was invented. In simple terms this means the processing power and speed of computers will double every two years. This remarkable observation was preceded by a number of inventions and innovations by scientists and engineers. These inventions and innovations played critical role in the advancement of integrated circuits. For example, the invention and advancement of complementary metal-oxide semiconductor made possible extremely dense and high performance ICs that are in use today.

Chip

With this possibility of putting millions of these tiny switches (transistors) on a chip the computing powers and speed has gone to unprecedented level. The invention of the DRAM (Dynamic Random Access Memory) made it easier to fabricate single transistor memory cells. Its the invention of DRAM and flash memory that made feasible the manufacturing of low-cost and high capacity memory we have today. As the number of transistors on a microprocessor chip increases since the Intel 4004 in 1970 the question arises how long before we reach the limits of miniaturization of these tiny switches otherwise known as transistors. Or could there be something revolutionary in the pipeline? 

Solar, remedy for electric pain

Renewable energy and specifically solar energy has seen spectacular rise globally. In my university there are two major buildings that I know of which has got solar panels installed on rooftop. With plenty of sunshine and somehow large storage there will be guarantee of uninterrupted power in those buildings in case WAPDA, the Water and Power Development Authority, switches off in the course of their notorious load-shedding routine. Thanks to the Heavy-duty batteries now you can literally harvest energy from your rooftop and lock it up in your store. According to the IEA (International Energy Agency) the cost of solar panel has reduced by five fold over the last six years and the cost of installation of the photo-voltaic system by three fold within this same period. Also according to an article by a physicist, Dr. Pervez H the ‘Levelised cost’, the total cost of installing a renewable-energy system divided by its expected energy output over its lifetime, is now close to the retail electricity in some countries. 

A recent statistics I came across states that the sun radiates around 23,000 Terawatts annually and the estimates of current global potential is: coal 900TerraWatts per year, Uranium 90-300TeraWatts per year, Oil 240TeraWatts per year and natural gas 215TeraWatts per year totaling to 1655 TeraWatts in one year which is a round 7% of what the sun radiates. With the expectation of being the dominant energy source in the next one or two decades as the physicist says many countries have decided to embrace it en masse and sooner or later it will be become the energy of choice in many households. In china, for instance, where there is less sunshine relative to Africa, Dr. Pervez says every rooftop has solar panel and the extra rooftop space up for rent to those who need extra energy. In India according to a report by Deutsche Bank solar will provide 25 percent of India’s power capacity. In United States, a leading consumer of global energy, electricity from solar panels and wind turbines is expected to be as cheap as the standard grid electricity. Solar energy, apart from being cheap it’s also the energy of choice in the mitigation of global warming phenomenon. In Germany and Japan solar powered autos are becoming popular and if the news I read sometimes back, German auto industries going solar, is anything to go by, then soon they will flood our streets and this will happen quickly like ICT did. 

Unlike china and India in Asia, in Sub-Sahara Africa, region with the highest solar radiation many still don't have access to electricity. With reports of the region's remarkable economic growth more is expected to be done in the energy sector to sustain this growth.And with many tech-cities coming up in major cities, powering them with solar will not only reduce the cost of electricity but also substantially reduce the load on the national grids thereby increasing energy surplus for industrial needs.