Radio Cell Planning

Frequency Hopping

• Algorithm
• At frequency hopping MAIO values are used (together with the HSN and the current FN) to point out the frequencies to be used from the HFS at an instant in time.
• HFS : Hopping Frequency Set
• Cyclic hopping
• "pointer" = (MAIO+FN) modulo (number of frequencies in HFS)
• Random hopping
• "pointer" = (MAIO+ random value) modulo (number of frequencies in HFS)

Example

Cyclic hopping, 3 TRX:s in a cell, nine frequencies in the HFS. The current FN is 1.

The first TRX use frequency number:

(FN+MAIO) mod (# of frequencies in HFS) = (1+0) mod 9 = 1 (which will relate the pointer to the second frequency in the HFS

The next time FN=2 and the pointers will be shifted downwards one step.

0, 2, 4

Default MAIO list:

HFS

0
1
2
3
4
5
6
7
8

2
4
7
12
17
21
22
31
33

Pos.

4

2

0