DECT Repeater cascade setup - number of units

Matter: How the number of DECT Repeaters in a cascade setup gets limited by transmission time of data packages.
Description

 

The performance of DECT Repeater depends on the support and the limitations of the asso-ciated base station in the DECT network. You can arrange up to 5 repeaters, but rarely those scenarios are useful or meet the expectations for performance in practice.

Generally, a maximum of 3 repeaters in star or 2 in cascade arrangement are recommended. In accordance with DECT resource requirements, mixed setups are possible, too.

Star setup:

casc stern                       

Cascade setup:

casc casc         

 

Here a normal DECT message package flow during a phone call of a handset in a DECT Repeater cell:

 casc mess

 

The data package will be sent from the handset to the basestation via the DECT Repeater and the basestation acknowledges the receipt of the data package. If acknowledgement is positive, the DECT Repeater will send the next data package.
If acknowledgement is negative, the DECT Repeater will resend the data package:

 casc mess error

            

The more Repeaters are in a chain, the more time this transmission and eventually retransmission takes. So the connection with the handsets in the farthest cells gets more erroneous because more data packages can not arrive on time and time lags appear. If the package has to be retransmitted, the transmission time multiplies in addition:         

 casc casc t

 

In the star setup this time lags do not appear because the path from a handset to the basestation just goes via 1 repeater:

 casc stern t