2.5 G
2.5G is a stepping stone between 2G and 3G cellular wireless technologies. The term "second and a half generation" is used to describe 2G-systems that have implemented a packet switched domain in addition to the circuit switched domain. 2.5G provides some of the benefits of 3G (e.g. it is packet-switched) and can use some of the existing 2G infrastructure in GSM and CDMA networks. GPRS is a 2.5G technology used by GSM operators
3G
International Mobile Telecommunications-2000 (IMT-2000), better known as 3G or 3rd Generation, is a family of standards for mobile telecommunications defined by the International Telecommunication Union, which includes GSM EDGE, UMTS, and CDMA2000 as well as DECT and WiMAX. Services include wide-area wireless voice telephone, video calls, and wireless data, all in a mobile environment. Compared to 2G and 2.5G services, 3G allows simultaneous use of speech and data services and higher data rates (up to 14.0 Mbit/s on the downlink and 5.8 Mbit/s on the uplink with HSPA+). Thus, 3G networks enable network operators to offer users a wider range of more advanced services while achieving greater network capacity through improved spectral efficiency.
The new services which we will get from 3g are Fast Communication, Internet, Mobile T.V, Video Conferencing, Video Calls, Multi Media Messaging Service (MMS), 3D gaming, Multi-Gaming etc
TERMS TO GET CLEAR
NARROW BAND AND WIDE BAND
2G OPERATES IN NARROW BAND AND > 3G OPERATES IN WIDE BAND
Wireless systems can be classified according to whether they have a narrowband or wideband architecture. Narrowband systems support low-bit-rate transmission, whereas wideband systems support high-bit-rate transmission. A system is defined as narrowband or wideband depending on the bandwidth of the transmission physical channels with which it operates
The coherence bandwidth is defined as the frequency band within which all frequency components are equally affected by fading due to multipath propagation phenomena. Systems operating with channels substantially narrower than the coherence bandwidth are known as narrowband systems. Wideband systems operate with channels substantially wider than the coherence bandwidth. In narrowband systems, all the components of the signal are equally influenced by multipath propagation. Accordingly, although with different amplitudes, the received narrowband signal is essentially the same as the transmitted narrowband signal. In wideband systems, the various frequency components of the signal may be differently affected by fading.
In wireless telecommunications, multipath is the propagation phenomenon that results in radio signals reaching the receiving antenna by two or more paths. Causes of multipath include atmospheric ducting, ionospheric reflection and refraction, and reflection from water bodies and terrestrial objects such as mountains and buildings. The effects of multipath include constructive and destructive interference, and phase shifting of the signal. This causes Rayleigh fading.
2.5G is a stepping stone between 2G and 3G cellular wireless technologies. The term "second and a half generation" is used to describe 2G-systems that have implemented a packet switched domain in addition to the circuit switched domain. 2.5G provides some of the benefits of 3G (e.g. it is packet-switched) and can use some of the existing 2G infrastructure in GSM and CDMA networks. GPRS is a 2.5G technology used by GSM operators
3G
International Mobile Telecommunications-2000 (IMT-2000), better known as 3G or 3rd Generation, is a family of standards for mobile telecommunications defined by the International Telecommunication Union, which includes GSM EDGE, UMTS, and CDMA2000 as well as DECT and WiMAX. Services include wide-area wireless voice telephone, video calls, and wireless data, all in a mobile environment. Compared to 2G and 2.5G services, 3G allows simultaneous use of speech and data services and higher data rates (up to 14.0 Mbit/s on the downlink and 5.8 Mbit/s on the uplink with HSPA+). Thus, 3G networks enable network operators to offer users a wider range of more advanced services while achieving greater network capacity through improved spectral efficiency.
The new services which we will get from 3g are Fast Communication, Internet, Mobile T.V, Video Conferencing, Video Calls, Multi Media Messaging Service (MMS), 3D gaming, Multi-Gaming etc
TERMS TO GET CLEAR
NARROW BAND AND WIDE BAND
2G OPERATES IN NARROW BAND AND > 3G OPERATES IN WIDE BAND
Wireless systems can be classified according to whether they have a narrowband or wideband architecture. Narrowband systems support low-bit-rate transmission, whereas wideband systems support high-bit-rate transmission. A system is defined as narrowband or wideband depending on the bandwidth of the transmission physical channels with which it operates
The coherence bandwidth is defined as the frequency band within which all frequency components are equally affected by fading due to multipath propagation phenomena. Systems operating with channels substantially narrower than the coherence bandwidth are known as narrowband systems. Wideband systems operate with channels substantially wider than the coherence bandwidth. In narrowband systems, all the components of the signal are equally influenced by multipath propagation. Accordingly, although with different amplitudes, the received narrowband signal is essentially the same as the transmitted narrowband signal. In wideband systems, the various frequency components of the signal may be differently affected by fading.
In wireless telecommunications, multipath is the propagation phenomenon that results in radio signals reaching the receiving antenna by two or more paths. Causes of multipath include atmospheric ducting, ionospheric reflection and refraction, and reflection from water bodies and terrestrial objects such as mountains and buildings. The effects of multipath include constructive and destructive interference, and phase shifting of the signal. This causes Rayleigh fading.
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