Technical Descriptions; Fhss Description - Panasonic KX-TG6700B Service Manual

4 Technical Descriptions

4.1.

FHSS Description

4.1.1. Frequency
The frequency range of 5.76 GHz-5.84 GHz is used. Transmitting and receiving channel between Base Unit and Handset is same
frequency. Refer to Frequency Table (P.88).
4.1.2. 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 tele-
phone system that can use multiple portable unit simultaneously. The explanation of this system is mentioned below. This sys-
tem 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 10 ms. 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 10 ms
according to Hopping table. Also the purpose to make spectrum spread is to reduce power density per time and per band.
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KX-TG6700B/KX-TG6702B/KX-TGA670B