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Reply To: Frequency Hopping System

#41308
Boboo
Guest

Hi all,
I found an exemple in SFH with nortel. I hope it wiil be clear.

MA: Mobile Allocation (list of hopping frequencies for a TRX)
MAIO: Mobile Allocation Index Offset between 0 and (Nb of Freq in MA – 1).
F1: BCCH frequency
HSN : Hopping Sequence Number

TS 0 1 2 3 4 5 6 7
TDMA 0 F1 F1 F1 F1 F1 F1 F1 F1
TDMA 1 MA0 MA0 MA0 MA0 MA0 MA0 MA0 MA0 MAIO = 0
TDMA 2 MA0 MA0 MA0 MA0 MA0 MA0 MA0 MA0 MAIO = 2
TDMA 3 MA0 MA0 MA0 MA0 MA0 MA0 MA0 MA0 MAIO = 4

TDMA 0 is mapping on TRX 0
TDMA 1 is mapping on TRX 1
TDMA 2 is mapping on TRX 2
TDMA 3 is mapping on TRX 3

So there is 4 TRX. TDMA0 don’t hop because it’s the TDMA with BCCH. BCCH equal to F1.

MA is the same for all TRX. 1,2,3,4,5,6,7,8,9 for exemple.

TDMA 1 hop with the frequency in the MA without offset(MAIO). So It’s 1,2,3,4,5,6,7,8,9,
TDMA 2 hop with the frequency in the MA with an offset equal to 2. So it’s 3,4,5,6,7,8,9,1,2,
TDMA 3 hop with the frequency in the MA with an offset equal to 2. So it’s 3,4,5,6,7,8,9,1,2
Etc …
In this case the HSN is equal to 0. the hopping sequency is not a random sequence.

It’s an pedagogic exemple. It’s just a way to understand how does it work. According to my experience, there are one HSN & on MAIO by sector. So You could apply this strategy on site level if you implement the same MA by sector with different HSN & MAIO

I hope it’s a bit more clear

Regards

Boboo.