Instruction manual

2-42
BreezeACCESS Version 4.3 Operations and Administration
Manual Revision: 4.0
b.The index of each of the other channels is calculated
by adding the Spanning Factor to the index of the
previous channel. Note that the sequence is cyclic,
meaning that adding 1 to the highest index in the
sequence (Index=N where N is the number of channels in
the sequence) will result in the first channel (Index=1).
The scrambled basic sequence can also be calculated
using the following formula:
P
x
(j)= {[(j-1)*X]mod(N)}+1
Where:
X is the Spanning Factor
N is the number of channels in the sequence (modulus)
J is the sequence index
Example: N=8, X=3
P
1
(5)={[(1-1)*3}mod8}+1=1
P
2
(5)={[(2-1)*3}mod8}+1=6
P
3
(5)={[(3-1)*3}mod8}+1=3
P
4
(5)={[(4-1)*3}mod8}+1=8
P
5
(5)={[(5-1)*3}mod8}+1=5
P
6
(5)={[(6-1)*3}mod8}+1=2
P
7
(5)={[(7-1)*3}mod8}+1=7
P
8
(5)={[(8-1)*3}mod8}+1=4
And the basic scrambled sequence is:
1, 4, 7, 2, 5, 8, 3, 6.
 Manual Sequence Definition – Manually defines the
hopping sequence, using numbered channel indexes (from 1
to “Number of Hopping Frequencies”). The sequence length
must be equal to “Number of Hopping Frequencies” (all the
defined frequencies must be used).
 Erase Manual Sequence – Erases the manually defined
hopping sequence.
Spanning Factor (AU only) – Defines the Spanning
Factor to be used by the Enhanced Scrambling
mechanism. The Spanning Factor should be chosen so
that the GCD (Greater Common Divisor) of the Spanning
Factor and the Number of Hopping Frequencies would
be 1 (e.g. for 8 frequencies possible values for the
Spanning Factor are 1, 3, 5 and 7). The SU learns the
value of the Spanning Factor from the AU during the
association process.Use of different spanning factors by
non-synchronized neighboring base stations reduces the
probability of interference between adjacent sectors.