Good glossary!!! 264992_633928070709161250

GLOBAL SYSTEM FOR MOBILE

HISTORY The Europeans realized this early on,

and in 1982 the Conference of European Posts and Telegraphs (CEPT) formed a study group called the Groupe Spécial Mobile (GSM) to study and develop a pan-European public land mobile system. The proposed system had to meet certain criteria:

PURPOSES Good subjective speech quality Low terminal and service cost Support for international roaming Ability to support handheld terminals Support for range of new services and

facilities Spectral efficiency ISDN compatibility

ARCHITECTURE ARCHITECTURE

GSM network consists of the following components:    

Mobile station. The GSM mobile station (or mobile phone) communicates with other parts of the system through the base-station system.

SIM:Subscriber Identification Module. A SIM card contains its unique serial number, international unique number of the mobile user (IMSI), security authentication and ciphering information, temporary information related to the local network (also temporary local id that has been issued to the user), a list of the services the user has access to and two passwords (PIN for usual use and PUK for unlocking).    

GSM Base station system (BSS).    

Base transceiver station (BTS). The base transceiver station (BTS) handles the radio interface to the mobile station. The base transceiver station is the radio equipment (transceivers and antennas)    

Base station controller (BSC). The BSC provides the control functions and physical links between the MSC and BTS. It provides functions such as handover, cell configuration data and control of RF power levels in base transceiver stations. A number of BSCs are served by a MSC

GSM Switching System

 Mobile services switching center (MSC). The MSC performs the telephony switching functions of the system. It also performs such functions as network interfacing, common channel signalling, and others.

 Home location register (HLR). The HLR database is used for storage and management of subscriptions. The home location register stores permanent data about subscribers, including a subscriber's service profile, location information, and activity status. 

    Visitor location register (VLR). The VLR database contains temporary information about subscribers that is needed by the mobile services switching center (MSC) in order to service visiting subscribers. When a mobile station roams into a new mobile services switching center (MSC) area, the visitor location register (VLR) connected to that MSC will request data about the mobile station from the HLR, reducing the need for interrogation of the home location register (HLR).  

   Authentication center (AUC). The AUC provides authentication and encryption parameters that verify the user's identity and ensure the confidentiality of each call. The authentication center (AUC) also protects network operators from fraud.

 Equipment identity register (EIR). The EIR database contains information on the identity of mobile equipment to prevent calls from stolen, unauthorized or defective mobile stations.

CALL IN PROGRESS- STEPS 1) MS initialization after switched-on 2) Service request 3) Authentication and security 4) MS attach and detach 5) Location update 6) Outgoing voice call 7) Incoming voice call 8) SMS and special services 9) Call hand over

GSM SPECIFICATIONS-1RF SpectrumGSM 900 Mobile to BTS (uplink): 890-915 Mhz BTS to Mobile(downlink):935-960 Mhz

GSM 1800 Mobile to BTS (uplink): 1710-1785 Mhz BTS to Mobile(downlink): 1805-1880 Mhz

GSM SPECIFICATIONS-2

Carrier Separation : 200 Khz Duplex Separation : 45 Mhz No. of RF carriers : 124 Access Method : TDMA/FDMA Modulation Method : GMSK Modulation data rate : 270.833 Kbps

FDMA Frequency Division Multiple

Access or FDMA is a channel access method used in multiple-access protocols as a channelization protocol. FDMA gives users an individual allocation of one or several frequency bands, or channels

TDMA Time division multiple access (TDMA)

is a channel access method for shared medium networks. It allows several users to share the samefrequency channel by dividing the signal into different time slots. The users transmit in rapid succession, one after the other, each using his own time slot.

EVOLUTION

1-G 1G (or 1-G) refers to the first-generation of 

wireless telephone technology, mobile telecommunications.

The 1G system in GSM all power allocation and handoffs strategies were decided by MSC and then executed by BSC.

2-G GSM differs from its predecessors in that

both signaling and speech channels are digital, and thus is considered a second generation (2G) mobile phone system.

GSM also pioneered a low-cost (to the network carrier) alternative to voice calls, the short message service (SMS, also called "text messaging").

The basic difference is that the interfernce of MSC is reduced as compared to 1-G the power and handoff allocation depends on THE BSC unless in the case of roaming where the MSC’s are different.

2.5-G

2.5 Generation ( Future of GSM)

HSCSD (High Speed ckt Switched data)

Data rate : 76.8 Kbps (9.6 x 8 kbps)

GPRS (General Packet Radio service)Data rate: 14.4 - 115.2 Kbps

EDGE (Enhanced data rate for GSM Evolution)Data rate: 547.2 Kbps (max)

HSCSD-High-speed circuit-switched data is the ability to use multiple time slots at the same time. Using the maximum of four time slots, this can provide an increase in maximum transfer rate of up to 57.6 kbit/s.

GPRS – General Packet Radio Service (GPRS) is a packet oriented Mobile Data Service available to users of Global System for Mobile Communications (GSM).

GPRS can be used for services such as WAP access, SMS, MMS, and for Internet communication services such as email and World Wide Web access. 2G cellular systems combined with GPRS are often described as "2.5G", that is, a technology between the second (2G) and third (3G) generations of mobile telephony.

EDGE – Enhanced Data rates for GSM Evolution (EDGE) is a digital mobile phone technology that allows increased data transmission rates and improved data transmission reliability. EDGE is generally classified as 2.75G, although it is part of the 3G definition.

3-G

3G is the third generation of telecommunication hardware standards and general technology for mobile networking.

3G networks enable network operators to offer users a wider range of more advanced services while achieving greater network capacity through improved spectral efficiency. Services include wide-area wireless voice telephone, video calls, and broadband wireless data, all in a mobile environment.

Additional features also include HSPA data transmission capabilities, which provides users with data rates up to 14.4 Mbit/s on the downlink and 5.8 Mbit/s on the uplink.

HSPA:High-Speed Packet Access (HSPA) is a 3G mobile telephony communications protocol in the HSPA family, which allows networks based on Universal Mobile Telecommunications System (UMTS) to increase data capacity and speed up transfer rates.

HSPA+ - HSPA+, also known as Evolved HSPA is a wireless broadband standard that provides HSPA data rates up to 42 Mbit/s on the downlink and 22 Mbit/s on the uplink .

UMTS – Universal Mobile Telecommunications System (UMTS) is one of the third-generation (3G) cell phone technologies, which is also being developed into a 4G technology. It is closely related to GSM/EDGE as it borrows and builds upon concepts from GSM

4-G 4G working group has defined the

following as objectives of the 4G wireless communication standard:

A spectrally efficient system . High network capacity: more

simultaneous users per cell.

A nominal data rate of 100 Mbit/s while the client physically moves at high speeds relative to the station, and 1 Gbit/s while client and station are in relatively fixed positions as defined by the ITU-R.

A data rate of at least 100 Mbit/s between any two points in the world.

Smooth handoff across heterogeneous networks.

Seamless connectivity and global roaming across multiple networks.

High quality of service for next generation multimedia support (real time audio, high speed data, HDTV video content, mobile TV, etc).

Interoperability with existing wireless standards.

IP, packet switched network.

LTE – Long Term Evolution (LTE) is the name given to a project to improve the UMTS mobile phone standard to cope with future technology evolutions. Goals include improving spectral efficiency, lowering costs, improving services, making use of new spectrum and reframed spectrum opportunities, and better integration with other open standards.

CDMA CDMA employs analog-to-digital conversion (

ADC) in combination with spread spectrum technology. Audio input is first digitized into binary elements. The frequency of the transmitted signal is then made to vary according to a defined pattern (code), so it can be intercepted only by a receiver whose frequency response is programmed with the same code, so it follows exactly along with the transmitter frequency. There are trillions of possible frequency-sequencing codes, which enhances privacy and makes cloning difficult.

CDMA CELL

GSM CELL

THANX