What is 4G? One of the terms used to describe 4G is MAGIC. It will provide a comprehensive IP solution wherevoice , data and multimedia can be given to user on an“anytime , anywhere” basis. It includes several types of broadband wirelesscommunication system access including cellular telephone system.
History of 4G technologyTechnology 1G 2G 3G 4GDesign began 1970 1980 1990 2000Implementation 1984 1991 2002 2010?Services Voice Associated Global Higherprovided transmission, with GSM Roaming, capacity text message service interactive ,completely media IP oriented, multimedia.Data bandwidth 1.0Kbps 144Kbps 2Mbps 100Mbps
Why 4G is required? Due to substantial growth in overall number of subscribers. Due to massive demand of new services like data , audio , image or video .
Features of 4G Technology Support for multimedia services like teleconferencing and wireless internet. Wider bandwidths and higher bitrates. Global mobility and service portability. Support for previous wireless technologies. High internet speed. Tight network security. Better spectral efficiency.
Problems with the Current System• Cellular networks do not have available bandwidth needed to handle data services well.• Data transfer tends to come in bursts.
Technology and hardware used in 4G OFDM UWB Smart antennas IPv6Software defined ratio
OFDM (orthogonal frequency division multiplexing) It is based on the concept of FDD (Frequency division multiplexing). It works by splitting the radio signal into multiple smaller sub-signals By inserting a cyclic prefix between adjacent OFDM signal inter signal interference can be avoided . Here modulation can be performed by an IDFT ,which can be generated very efficiently as an IFFT . so, receiver only needs a FFT to reverse this process.
UWB (ultra wide band) .An advanced technology that can be used in 4G technology. It is typically detected as noise. It uses a frequency of 3.1 to 10.6 GHz. It uses less power as it transmits pulse instead of continuos signal. Special antennas are needed to tune and aim the signal.
Smart antennas• A digital wireless communication antenna system that takes advantage of diversity effect at source, destination or both.• They can send back signals in the same direction that they came from.• They can fall into SIMO, MIMO and MISO.
Software defined radio (SDR) A software defined radio is one that can be configured to any radio or frequency standard through the use of software. The phone should automatically switch from operating on a CDMA frequency to a TDMA frequency whenever it is required. It can be dynamically updated with new software without any changes in the hardware and infrastructure.
Packet Layer• Splits the data into small packets.• Without this there would be a need of separate connection on each computer with a separate network and routing equipment.• They follow rules how they are formatted.
IPv6 The Internet Protocol (IP) is the method or protocol through which data is sent from one computer to another on the internet. It includes128 bits, which is 4 times more than 32bits IP address in IPv4. Understanding of IPv6 in 4G- - 32 bits IP address looks like this 126.96.36.199 - 188.8.131.52 may be written like 11011000.00100101.10000001.00001001 - the IP address in IPv6 version will be 4 times of IPv4; it looks like 184.108.40.206,220.127.116.11,18.104.22.168,192.168.5.120 - all 4 sets are defined in different functions and usages. - the first set of the IP address (22.214.171.124) can be defined to be the “home address” purpose.
IPv6 continue…… The second set of the IP address (126.96.36.199) can be declared as the “care-of address”. The third set of the IP address (188.8.131.52) can be signed as mobile IP address. The last set of IP address(192.168.5.120) can be local network address.There are enough addresses for every phone to have a unique address.
Advantages of Packets• More secure• More flexible• More reliable• Proven technology• Easier to standardize• Extensible
QOS (quality of service) In wireless networks, Quality of Service (QOS) refers to the measure of the performance for a system reflecting its transmission quality and service availability. 4G is expected to have at least a reliability of 99.99%. In 4G QOS may be divided in following ways- Transaction-level QOS describes both the time it takes to complete a transaction and the packet loss rate. Circuit-level QOS includes call blocking for new as well as existing calls . User-level QOS depends on user mobility and application type .