Cordect Wireless Access System

welcome

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CorDECT Wireless access system

Binoop krishna.k.g Electronics & communication Gptc.Nta

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INTRODUCTION CorDECT is a WAS, provide simultaneous access of quality voice & internet (35/70kbps) Develop by IITM,Midas communications & Analog Devices Inc., USA Based on microcellular architecture The DECT standard proposed by ETSI

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Conceptual Access System

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corDECT Wireless Access System

corDECT

WAS 5

corDECT Wireless Access System

CBS remote

to DIU trough BSD 6

corDECT Wireless Access System

WS-IP connected to DIU link trough RBS

radio link

using a 2 hop radio 7

Wallset IP and Wallset Ø Voice connectivity to the subscriber using a RJ-11 interface G3 fax machine, PCO, speaker phone, codeless phone, modem Ø Internet through RS-232 port direct connection without modem, establish PPP supporting 35/70kbps

ØAntenna port externally mounted 12 v adaptor connected to AC

Ø

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Voice port

Antenna port

RS-232 port

Wall set IP Multtiwallset

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Compact Base Station ( CBS ) Ø Provides radio interface between DIU & subscriber terminals Ø supports up to 12 simultaneous voice calls Ø The CBS has two antennas for diversity. Ø Omni-directional antennas are used 360 coverage Ø maximum LOS range is 10 km. Ø 30 - 70 subscribers Ø Remotely powered from DIU or BSD.

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DECT Interface Unit ( DIU ) Ø DIU is the heart of corDECT Wireless Access System Ø DIU function as Switch, Base Station Controller, Operation & Maintenance Console (OMC) Ø DIU can support up to 20 CBS Ø DIU acts as a 1000-line exchange Ø RAS terminates the PPP connections from Internet users

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iKON

DIU

RAS

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RELAY BASE STATION ( RBS )

ØPlace b/w CBS & subscriber unit ØExtent the range of corDECT system ØConsisting 3 antennas ØHigh gain directional antenna receives signal from CBS Ø2 Omni directional antennas uses ØMaximum LOS range b/w CBS and RBS is 25 km ØMaximum LOS range b/w RBS & subscriber is 10 km

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INTERNET CONNECTION

ØRAS terminates PPP connection of all internet subscribers ØIP packets routed to internet by RAR ØRouter can carry internet traffic from other access system

Internet connection using local router

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TECHNICAL DETAILS Ø ØFrequency Band:

RF band allotted to DECT is 1880-1900MHz(20MHz) Extended band 1990-1935 MHz also defined ØVoice digitalization: 32 kbps ADPCM Ensure toll quality& permits all data services (fax,modem) ØMode of access MC-TDMA(Multi Carrier Time Division multiple Access) ØChannel Allocation Dynamic channel selection (DCS)

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MC - TDMA

( Multi Carrier - Time Division multiple Access )

Ø The DECT system has 10 radio frequency carriers in 20MHz band width Ø Two groups of 12 slots each one group for each direction to transmission. Ø Each time slots act as a channel Ø 12 X 10=120 channels Ø Frame duration is 10ms & slot pair separated by 5 ms Ø Each carrier is divided into frames of 24 time slots

DECT frame structure

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Dynamic channel selection ( DCS ) Ø DECT consist 120 channels Ø Ø Wallset make a RSSI measurement for each time slot Ø chooses a channel providing lowest interference Ø Ø Ø 120 DECT channels 17

ADVANTAGES Ø Simultaneous access of voice & internet Ø Can inter work with other type of n/w such as PSTN,ISDN,GSM Ø Cost effective implementation Ø MC-TDMA & dynamic channel selection (DCS) are low cost technologies Ø DECT insures high capacity Ø Providing multi channels (120) Ø Voice quality Ø Easy to install & maintenance 18

Major subscriber services Ø Alarm call service Ø Call waiting Ø Dual telephone number Ø Call diversion on no replay & busy Ø Conference calling Ø Malicious call identification Ø Ø 19

References www.tenet.res.in/cordect/cordect.html www.midascomm.com/products.htm www.developmentgateway.org www.i4donline.net www.wikipedia.com

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QUESTION TIME….

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