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swati verma
swati verma • Oct 26, 2008

Basics of 4G

I'm Swati Verma. I wish to understand the basics of 4G technology. All I know is the 4th Generation of mobile communications. Thanking you in advance.
durga ch
durga ch • Oct 26, 2008
hmmπŸ˜€
tough question

let's start from the beginning of telecom generations
1G(analog)->2G(digital)->3G,4G(multi media ) services

2G implemented the CDMA ,GSM multiplexing involved TDMA and basically circuit switching.

2.5G was GPRS which still involved TDMA but with both circuit switching and packet switching.

3G basically concentrated on the multi media data packets. ie till 2.5 or greater generations it was just voice packets, and messaging(signalling) packets which were sent..but later one.. when mobile phones( mobile techonlogy) had to be enhanced to include the data packet feature as well.. that is your MMS feature.. internet browsing, and all..

for this they not only needed higher band width.. but as well needed optimum untilsiation of these frequecies...
I dont think INDIA could implement 3G techonlogy. Its directly moving to 4G.. couple of yerars ago when I was into training.. i came to know that the 3G frequency was being used by Indian military forces and allocating that frequency to general use was not permitted.

migration to 3G and 4G involved UMTS network protocols, SIP,HSDPA enhancements ,CDMS 2000 , and wi fi wi max techonologies involving OFDM and COFDM techonlogies, MIMO along with IP architecture
3G basically concentrated on WCDMA,CDMA and then later by UMTS


as far as i can recon, 4G generally deals with wi-fi and wi-fi max..
though they tend to call it wireless fidelity.. thats not the basic intention... its was mentioned tht they used the phrase wi-fi only in rhym with hi fi and later redefined it as wireless fidelity

OFDM:
in OFDM...a specific band of frequency is allocated to the service provider..
instead of using the whole band to trasnmit signals.. they divide the band inot multiple sub channels.. u can imagine a truck of a tree with branches..

and now each subchannel carries data... πŸ˜€you might wonder how?? wont they intefere?? nah!!! thats where 'O'of OFDM comes into picture...
the sub carriers are choosen such that they maintain orhtogonality ie when the subcarriers are recieved at the reciever, the sum would equal to zero!!!ie orthogonal..

thus efficinet use of bandwidth..

apart form OFDM.. MIMO antenna system as well is use..( i am yet to get familiar with the JUMBO COMBO-MIMO OFDM!!!!)
in SISO ,, you have s single transmitting antenna and a single reciever antenna.. incase there is a loss of data the data is lost for ever.. where as in MIMO .. you have multiple input and multiple outputs.. say u have 2 antennas trasnmitting ans 2 recieving the same data packtes.,.. kind of creating redundancy..

since dats transmission is invloved,, we would as well be having a Internet layer protocol invloved... I guess wifi uses IPV4 or may be higer version.. not sureπŸ˜”

the 4G application iwreless LAN provides high speed mobile data communication and supports 3 topologies
peer to peer
acess point
point to multi point bridges


hope.. this helps!!

by the way .. this infor was form my previous training... so it might be a bit outdated!!! 😁
swati verma
swati verma • Oct 26, 2008
thank you, ma'am
durga ch
durga ch • Oct 26, 2008
nah!!

dont make me too old by calling "ma'am"!!πŸ˜›
swati verma
swati verma • Oct 26, 2008
plz tell me dear, wat sud i call u?
actually, i have to prepare an abstract so i need more nd more information on dis topic.
durga ch
durga ch • Oct 26, 2008
hmmm..

in that case you can give an abstract on transisting fomr 3G to 4G...and then apllications of 4G . this would help the listener / reader a better insight..

call me durga...πŸ˜€ that should be ok
Kaustubh Katdare
Kaustubh Katdare • Oct 26, 2008
*bump* @Swati - please refrain from using SMS text while posting on CE Forums!
Ya know, I'm thinking theres still a lot of room of 3G to exist. It hasnt fully matured yet. WiMax (which is still classified as 3G) has just been deployed city wide!

4G is still a long way in the future πŸ˜€
durga ch
durga ch • Oct 26, 2008
hey any idea what IP WiFi uses... I pressummed its IPV4
anuragh27crony
anuragh27crony • Oct 26, 2008
durga
hey any idea what IP WiFi uses... I pressummed its IPV4
Yeah it's IPV4...still IPV6 has not came into existence....
anuragh27crony
Yeah it's IPV4...still IPV6 has not came into existence....
Though its IPV4 only... just for knowledge...Excerpt from Wiki..

"IPv4 is currently the dominant Internet Protocol version, and was the first to receive widespread use. The Internet Engineering Task Force (IETF) has designated IPv6 as the successor to version 4 for general use on the Internet.

IPv6 has a much larger address space than IPv4, which provides flexibility in allocating addresses and routing traffic. The extended address length (128 bits) is intended to eliminate the need for network address translation to avoid address exhaustion, and also simplifies aspects of address assignment and renumbering, when changing Internet connectivity providers."
Windows Vista has native IPv6 support, it seems. Some organizations are doing some testing to implement IPv6 in parallel with IPv4.

The obstacle of implementing the new protocol is the cost of transition from IPv4. I guess it wont be a quick change as we would like it to be.

Anyway, IPv6 should be able to support us for a couple centuries, unless we start giving every object in the universe an IP address πŸ˜‰
ash
Windows Vista has native IPv6 support, it seems. Some organizations are doing some testing to implement IPv6 in parallel with IPv4.

The obstacle of implementing the new protocol is the cost of transition from IPv4. I guess it wont be a quick change as we would like it to be.

Anyway, IPv6 should be able to support us for a couple centuries, unless we start giving every object in the universe an IP address πŸ˜‰
Hey wait wait wait ASH... isn't it too early to say anything.

You never know when this technological driven crazy engineers would find some better version of IPv6 as well. 😁
crazyboy
Hey wait wait wait ASH... isn't it too early to say anything.

You never know when this technological driven crazy engineers would find some better version of IPv6 as well. 😁
Haha, I know what you mean πŸ˜›

However, improvements to the protocol will just update it's definition. It's like Windows XP.. theres always patches going on. But its still XP πŸ˜‰ Unless theres a total concept change and we require even more bits!

Of course centuries would fly very quick πŸ˜‰
durga ch
durga ch • Oct 27, 2008
I read some where...I really cant recollect where..
the present IPV4 using 32bits for addressing and they would be exhausted by 2009!!!

but CISCO says something else..

wanna read??

IPv4: How long do we have? - The Internet Protocol Journal - Volume 6, Number 4 - Cisco Systems

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