University:
College
Course:
College Engineering
Academic year:

2023
Views:

305

Pages:

2
Author:

Dipin K.

Cordless Telephony and Low-Tier PCS It describes two cordless telephony technologies, CT2 and DECT, and two low-tier PCS technologies PHS and PACS. Cordless Telephone, Second Generation (CT2): Developed in Europe, and has been available since 1989. CT2 is allocated 40 FDMA channels with a 32-Kbps speech coding rate. For a user, both base-top handset signals and handset-tobase signals are transmitted in the Same frequency. The maximum transmit power of a CT2 handset is 10 mW. In the call setup procedure, CT2 moves a call path from one radio channel to another after three seconds of handshake failure. CT2 also supports data transmission rates of up to 2.4 Kbps through the speech code and up to 4.8 Kbps with an increased rate. CT2 does not support handoff and in a public CT2 system, call delivery is not supported. Digital European Cordless Telephone (DECT) The Digital European Cordless Telephone has been replaced by Digital Enhanced Cordless Telephone to denote global acceptance of DECT. DECT supports high user density with a picocell design. There are 12 voice channels per frequency carrier. Sleep mode is employed to converse handset power. DECT also supports seamless handoff. DECT is typically implemented as a wireless-PBX (Private Brach Exchange) connected to PSTN. DECT can interwork with GSM to allow user mobility. Personal Handy Phone System (PHS) PHS is a standard developed by the Research and Development Center for Radio Systems (RCR), a private standardization organization in Japan. PHS is a low-tier digital PCS system that offers telecommunication services for homes, offices, and outdoor environment, using radio access to the public telephone network or other digital networks. PHS uses TDMA. Sleep mode enables PHS to support five hours of talk time, or 150 hours of standby time. PHS operates in the 1895 - 1918.1 MHz band. The bandwidth is partitioned into 77 channels, each with 300 kHz bandwidth. The band 1906. 1-1918.1 MHz (40 channels) is designed for public systems, and the band 1895-1906.1 MHz (37 channels) is used for home/office applications. Personal Access Communications Systems (PACS) PACS is a low-power PCS system developed at Telcordia (formerly Bellcore). TDMA is used in PACS with eight voice channels per frequency carrier. In FDD mode, the PACS uplink and downlink utilizes different RF carriers, similar to cellular systems. The highly effective and reliable mobile-controlled handoff (MCHO) completes in less than 20 msec. Cordless and Cordless Low-tier PCS Telephony Overview Following Table presents the overview of cordless and cordless low-tier PCS telephony: system High-tier Cellular Low-tier PCS Cordless Cell size User speed Coverage area Handset complexity H-set power use Speech coding rate Delay or latency Large (0. 4-22 mile) High (less than 160mph) Large/Continuous Macro cell High High Low High Medium (30-300') Medium (60 mph) Small (30-60") Low (30 mph) Medium Micro and pico cell Low Low High Low Small Zonal cell Table gives an overview of cordless and cordless low-tier PCS telephony Low Low High Low