Instruction manual

Menus and Parameters
2-43
BreezeACCESS Version 4.5 System Manual
1. The first channel in the basic scrambled sequence is frequency 1.
Frequency 1 (index=1) is the lowest frequency in the list of
frequencies to be used, frequency 2 is the next frequency and so
on.)
2. 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) results in the first channel (Index=1).
The scrambled basic sequence can also be calculated using the
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 - Defines the Spanning Factor for use by the
Enhanced Scrambling mechanism when seven or more frequencies
are used. The Spanning Factor should be chosen so that the GCD
(Greater Common Divisor) of the Spanning Factor and the Number
of Hopping Frequencies is 1 (for example 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.
The use of different spanning factors by non-synchronized
neighboring AUs reduces the probability of interference between
adjacent sectors.