Description; Frequency; Fhss (Frequency Hopping Spread Spectrum) - Panasonic KX-TG5631S Service Manual

KX-TG5631S / KX-TG5632M / KX-TG5633B / KX-TGA560S / KX-TGA560M / KX-TGA560B

9 DESCRIPTION

9.1.

Frequency

The frequency range of 5.76GHz-5.84GHz is used. Transmitting and receiving channel between Base Unit and Handset is same
frequency. Refer to Frequency Table (P.49).
9.2.

FHSS (Frequency Hopping Spread Spectrum)

This telephone is using an IC chip which has similar specification to WDCT (World Digital Cordless Telephone) and is the
telephone system that can use multiple portable unit simultaneously. The explanation of this system is mentioned below. This
system uses a Time Division Multiple Access/Time Division Duplex (TDMA/TDD) scheme:
transmitting and receiving frequencies of the Base Unit and Handset are shared in the same frequency. The construction of
RX/TX frequency data is shown below. It consists of 4 slots from the Base Unit to the Handset, and 4 slots from the Handset
to the Base Unit, total 8 slots in 10ms. By this slot system, simultaneous air link and communication between 4 Handsets and
the Base Unit can be realized. One communication between Handset and the Base Unit is done by one slot from the Base Unit
to Handset, and another slot from Handset to the Base Unit.
DSS makes spectrum spread by multiplying carrier signal by PN code. The purpose to make spectrum spread is to reduce
power density per time and per band. On the other hand, FHSS makes spectrum spread by changing channel every 10ms
according to Hopping table. Also the purpose to make spectrum spread is to reduce power density per time and per band.
52