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what is Frequency hopping

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  • GSM
Last response: in Technologies
May 27, 2005 2:22:28 AM

Archived from groups: alt.cellular.gsm (More info?)

Hello,
Can anyone please kindly explain me what is called frequency hopping in
GSM.
Thank you
With warm regards,
DD

More about : frequency hopping

Anonymous
May 27, 2005 11:04:45 AM

Archived from groups: alt.cellular.gsm (More info?)

On 26 May 2005 22:22:28 -0700, "dd" <duttdharm@yahoo.com> wrote:

>Hello,
>Can anyone please kindly explain me what is called frequency hopping in
>GSM.

http://ccnga.uwaterloo.ca/~jscouria/GSM/gsmreport.html#...

Frequency hopping
The mobile station already has to be frequency agile, meaning it can
move between a transmit, receive, and monitor time slot within one
TDMA frame, which normally are on different frequencies. GSM makes use
of this inherent frequency agility to implement slow frequency
hopping, where the mobile and BTS transmit each TDMA frame on a
different carrier frequency. The frequency hopping algorithm is
broadcast on the Broadcast Control Channel. Since multipath fading is
dependent on carrier frequency, slow frequency hopping helps alleviate
the problem. In addition, co-channel interference is in effect
randomized.



--

Regards

John Riggs
Anonymous
May 28, 2005 2:44:50 AM

Archived from groups: alt.cellular.gsm (More info?)

On 26 May 2005 22:22:28 -0700, "dd" <duttdharm@yahoo.com> wrote:

>Hello,
>Can anyone please kindly explain me what is called frequency hopping in
>GSM.
>Thank you
>With warm regards,
>DD
GSM is not known for frequency hopping, the only time it happens is
when your call is handed from one cell to another, the phone changes
channels to a channel on the new BTS.

By contreast CDMA is based upon splattering your call over 1.23 Mhz of
bandwidth. The Shannon theorem tells us that spread spectrum operation
is very hard to jam, and can operate with exceptionally poor S/N
ratios.
Related resources
Anonymous
May 28, 2005 2:39:43 PM

Archived from groups: alt.cellular.gsm (More info?)

matt weber a présenté l'énoncé suivant :
> GSM is not known for frequency hopping, the only time it happens is
> when your call is handed from one cell to another, the phone changes
> channels to a channel on the new BTS.

bullshit

--
Christophe

Couverture GSM Oléron 2003
http://chantoine3.free.fr
Anonymous
May 29, 2005 1:29:47 AM

Archived from groups: alt.cellular.gsm (More info?)

On Sat, 28 May 2005 10:39:43 +0200, "C Antoine"
<chantoine99marreduspam@riendutoo.fr> wrote:

>matt weber a présenté l'énoncé suivant :
>> GSM is not known for frequency hopping, the only time it happens is
>> when your call is handed from one cell to another, the phone changes
>> channels to a channel on the new BTS.
>
>bullshit

Hm..
GSM broadcasts on a fixed channel that is 200Khz wide, that is time
shared with up to 15 other calls (usuallh 7 other calls), using
Gaussian Phase Shift Keying.

Please tell me why you think transmitting with fixed bandwidth on a
fixed channel is frequency hopping?
Anonymous
September 20, 2012 6:56:42 PM

Quote:
Hm..
GSM broadcasts on a fixed channel that is 200Khz wide, that is time
shared with up to 15 other calls (usuallh 7 other calls), using
Gaussian Phase Shift Keying.

Please tell me why you think transmitting with fixed bandwidth on a
fixed channel is frequency hopping?


the usage of frequency hopping in GSM is optional; nevertheless its there. TDMA+freq hop is used to address the problem of channel fading.