Antenna Diversity

GDK-20W DIGITAL WIRELESS KEY TELEPHONE SYSTEM

Base stations may be mounted on wall or desktop up to 300 meters away from the wireless terminal interface ports using a twisted one pair cable(0.5φ). The system supports max. three base stations.

In typical office environments, each base station has a broadcast range of 50 meters and supports an area of 8,000 square meters. In settings where the absence of any obstruction provide perfect line of sight conditions between a base station and wireless terminal users and there are no atmospheric limitations, the range may increase to max.200 meters.

LEDs on the PCB of a base station provide diagnostic information for base station status.

Spatial diversity at the base station is implemented by using two antennas. The antenna providing the best signal for each time slot is selected. This is performed on the basis of the RF power level and alternatively the quality information.

In DECT, the BER(Bit Error Ratio) is affected by multi-path propagation not only in terms of signal fading but in terms of time dispersion, which leads to ISI(Inter Symbol Interference). Antenna diversity not only reduces the fading probability but mitigates the effect of time dispersion.

Power Feeding

The base station is DC powered from the WTI ports by phantom power feeding circuit between a WTI port and a base station.

Roaming

Roaming is the movement of a wireless terminal from one base station coverage area to another base station coverage area, where the base stations enable the wireless terminal to make or receive calls in both areas. The system supports roaming function.

Hand-over

The GDK-20W DECT provides a seamless hand-over, almost undetectable by users as they move from one radio cell to another.

Digital Voice Quality

The GDK-20W DECT uses advanced digital technology to provide high sound quality as almost equal to fixed line telephones. Speech coding uses 32kbps ADPCM(Adaptive Differential Pulse Code Modulation) conforming to CCITT recommendation G.721.

Multiple Simultaneous Users

The GDK-20W DECT accommodates multiple users(12 users) in simultaneous conversation with no degradation in performance.

C. Wireless Terminal (GDC-335H, GDC-340H)

The wireless terminal is designed for ease-of-use at the desks of users or moving throughout a facility.

zIt is small and light for ease-of-use.

zThe LCD displays call information and the status of terminal.

zThe keypad contains specially labeled keys assisting users to make calls and operate telephone features.