frequency hopping in gsm

Anyone care to explain to me what's the purpose of frequency hopping in a GSM network?

Can further explain what is synthesizer hopping n baseband hopping?

Thanks, folks!

You know that the number of frequencies for GSM is 124 and it is not much. The range is divided for some operators. What happen when the sites configuration is high? They do not have enough frequencies. One way, they expand their range to use CDS 1800. So, they have to spend more money.

From the time they discovered that the spread spectrum for the frequencies in their range is not used equally, some are used more, some are less. It makes high interference for the frequencies used more. Then frequency hopping is used. This technique is used to equanlized interference for the frequencies used in their range. There are two types of frequency hopping: baseband and syntherizer.

Added after 5 minutes:

The main technique for frequency hopping is that 1 carrier does not work with one frequency, but some and at least two.

- In baseband hopping, the transmitter will change its frequency on frame basis.
- In syntherizer hopping, the transmitter will change its frequency on time slot basis. That is why they also said it is fast hopping.

Note: hopping can use for traffic channel only, not for signalling channel

Hi ,

THanks for the information

Can u upload some detail material on FH especially on SFH and BFH

THanks

Can u post some matrial on GSM freq hopping ...