Marvelmind IA-04-2D-Badge, Operating Manual, Page: 234 / 263

234
11.3.2. TDMA sequence:
As far as we have only 5 ultrasonic frequencies, when we build big maps and when
ultrasonic signals may interrupt each other, we must use TDMA. In this case submaps that
cannot be used together will work alternately. Please notice that update rate falls by a
multiple of TDMA sequence. If you have 8Hz basic update rate without using TDMA, 3
TDMA sequences will make it 8/3Hz.
TDMA is the mode of sequential radiation, when for each stationary beacon the
number of the cycle in which it should emit and the number of cycles of radiation
after which these numbers are repeated is set
We have 3 TDMA types:
-
Type 1 -
TDMA as NIA multiple beacons’ working algorithm
-
Type 2 - Full-overlapping TDMA (For better coverage in 2D). See more on
TDMA chapter
-
Type 3 - TDMA for huge IA maps building (described below)
For building huge maps in IA, we need TDMA Type 3.
-
Example 1:
19kHz(j0, T1) 31kHz(j0, T1) 45kHz(j0, T1)
Submap0 Submap1 Submap2
31kHz(j0, T2) 45kHz(j0, T2) 19kHz(j0, T2)
Submap3 Submap4 Submap5
19kHz(j0, T2)
31kHz(j0, T1) 45kHz(j0, T1)
Submap1
31kHz(j0, T2) 45kHz(j0, T2)
Submap4
The same frequency sets
The same jitter codes for beacons
Different TDMA sequence
T\s
Submaps differ - CORRECT