Questions about GSM, EDGE, 3G and Multicode engineering

[qv1985]

Hi everybody!I have some questions about GSM that:
1.Why the bit rate in EDGE is Asymetric?
2.Why in the GSM use hard handover?
3.What the information in the Channel 15?
4.What is the Multicode engineering?
5.What the different of 3G with 1G,2G,2.5G?

 

[cabone]

Re: Questions about GSM

1.Why the bit rate in EDGE is Asymetric?
because of the fact that each user uses in the uplink time slots less than in the downlink so the uplink bitrate is less than downlink bitrate but if u r asking why they did that because usaualy users download data more than uploading and you will see that this is the case in any high bitrate system GPRS,EDGE,ADSL and UMTS
2.Why in the GSM use hard handover?
hard handover happens if the user tries to change the frequency of transmission and as in GSM you cant find the same frequency in two cells beside each other user will have to use hard handover which is not the case for UMTS because in UMTS we have the same frequencies in all the cells but of course you may have to use hard handover in UMTS
3.What the information in the Channel 15?
what do you mean by channel 15???????
4.What is the Multicode engineering?
i dont know what do you mean
5.What the different of 3G with 1G,2G,2.5G?
i dont think that you want me to answer this question in details because it will take a very very very long time
but the main difference that makes them make 2G is that 1G was analouge and it has all the analouge transmission problems after that they made 2.5G,3G,3.5G,3.75G and 4G mainly to increase the bitrate

 

[rickleicn]

Questions about GSM

5.What the different of 3G with 1G,2G,2.5G?
there are many differences between them.
physical layer:multi carrier,single carrier,MIMO,beamforming,channel code/decode,modulation,frequency...
MAC layer:QOS,mobility,RR....

 

[eng_tameremad]

Re: Questions about GSM

Hi
dear
i have a document can explain the answers of this questions i will attached it to u .
Thanx
BR\\
Tamer :!: :!: