Urban Traffic-OTN Application in Urban Traffic

There are 16 locations in the first phase of the project.

The prime purpose of OTN transmission system is to serve as a backbone communication system to provide interface and transmission channels of different audio, data and video applications between different locations of the whole light rail line for the 7 sub-systems including service telephone system, private ( special ) telephone system, radio communications, CCTV system, broadcasting system, clock system and power supply system listed in the tender specifications.

The structure of OTN allows reliable access and transmission to satisfy the requirement defined in the first phase of the Chongqing Light Rail project and offers scalability and flexibility for the second phase of the project.

Telephone Applications
(1) Service Telephone ( auto, rolling stock, standby ) ( 2-wire analog lines )
The program-controlled exchanges ( PABX ) installed at the Control Center and Depot provide telephone services to the users along all stations of the Chongqing Jiao-Xin Light Rail.

The OTN 12-port analog voice cards ( 12 LVOI-P and 12 LVOI-T ) and –48V Ring Generator modules are used to realize this telephone application.

To realize the 2-wire analog voice interface and transmission over OTN for the Chongqing Jiao-Xin Light Rail project, the 12LVOI-P cards are installed at the OTN nodes of Control Center and

12LVOI-T cards and the –48V Ring Generators are installed at the OTN nodes of the 14 stations and Depot.

(2) Dispatching Telephone for Local Power Station Dispatching application
To realize this application, the OTN UNIVO cards with the 2w/4w E&M modules are installed at the OTN nodes of Control Center , Dongwuyuan Station and Da Xiguo Station to provide the required 2w/4w voice interface and channel link for the telephone dispatching application over OTN.

(3) ISDN Telephone ( Standby ) application
To realize this application, the OTN ISDN ( 2B+D ) cards ( ISDN So-P card installed at the OTN node of Control Center and ISDN So-T card at the 14 stations and Depot ) are used to provide the required ISDN ( 2B+D ) transmission paths between the Control Center and the 14 stations and Depot over OTN.

The OTN ISDN cards are compliant with ITU-T I.430 recommendations.

Special Telephone Applications
The dispatching telephone of the special telephone system is to deal with the operations of the train dispatching, power distribution and environment control dispatching. The internal station is specially for station watchers to settle with train operations between stations and light rail operation inside stations.

The track side telephone is for communications between the tunnel workers and the station watchers or other units. To realize this application, the OTN E1 cards that offer 2Mbits channels are installed at the OTN nodes of the Control Center , 14 stations and Depot to inter-link the special telephone system between the Control Center and the stations / Depot over OTN.

The OTN E1 ( 2.048 Mbps ) interface card is compliant with ANSI T1.102, OFTEL OTR001 and ITU-T recommendations : G.703 and G.823.

Broadcasting system application
The OTN high quality ( 15 kHz sampling ) broadcasting cards ( HQAUD-M and HQAUD-S ) are used to realize this application.

To realize the broadcasting application, the OTN HQAUD-M card is installed at the OTN of Control Center and HQAUD-S cards are installed at the OTN node of the 14 stations. Through these OTN broadcasting cards, we can set up two 15 kHz audio channels and two control data channels in the whole transmission system for broadcasting's audio transmission and data control.

CCTV application
The OTN Video Management System ( VENUS ) and 4-port video cards ( VID4-IN-X and VID4-OUT-X ) are used to realize the above-mentioned CCTV applications.

There are 2 types of OTN 4-port video cards, namely, VID4-IN-X ( encoding side ) and VID4-OUT-X ( decoding side ). Each card offers 4 independent video channels for video transmission and video control channels for transmission of PTZ ( Pan, Tilt and Zoom ) signals and video management system data.

In their video functions, analog PAL or NTSC video signal are digitized and compressed by means of the M-JPEG algorithm on the VID4-IN-X video interface card. Then these digitally compressed signals are transported to another node over OTN. At this video decoding end, the compressed signal is decompressed and reconverted by the VID4-OUT-X video interface card into analog PAL or NTSC signal.

In the control functions, the OTN video cards also provide built-in RS485/422 data ports for transmission of PTZ control data and video management system command data.

Besides fixed-point video transmission, the manufacturer of OTN, Siemens Atea has developed a video switching software, OVS and a user-friendly mutli-user video management system, VENUS.

The PC-based VENUS has graphic user interface ( GUI ) to facilitate the man-machine interface.

VENUS, which has the single user and mult-user versions, allows users to easily use a PC mouse to command and navigate the video switching between the video inputs ( encoding end ) at the stations and the video outputs ( decoding end ) at the Control Center.

Automatic Fare Collection ( AFC ) application ( RS422 64 kbps )
Clock application ( RS422 64kbps )
Radio Communication application ( RS422 )
Power application ( RS422 64 kbps )
Signal application ( RS422 64 kbps )
To realize these applications, the OTN RSXMM cards are installed at the OTN nodes of the Control Center , 14 stations and Depot to provide point-to-point RS422 interface and transmission paths between the Control Center and the 14 stations and Depot over OTN.

The RSXMM card is compliant with EIA/TIA-232-E and EIA RS422 standard.

The RSXMM card has 12 point-to-point data ports plus 4 RTS/CTS ports.

It supports RS232 and/or RS422 asynchronous and synchronous data applications.

Power application ( 10Mbits )
FAS / BAS application ( 10M )
Signal application ( 10M )
Office Automation ( OA ) application ( 100M )
To realize these applications, a Fast Ethernet ( 10/ 100M ) card is installed at the OTN nodes of the 14 stations, Depot and the Control Center to form an Ethernet network over OTN and the bandwidth allocation of the Ethernet network for this application is set to 10M via the OTN management system ( OMS ).

OTN has the full capability of providing sufficient Ethernet interface and transmission bandwidth by adding Fast Ethernet ( 10/ 100M ) cards to the OTN nodes at the 14 stations, Depot and Control Center . The Ethernet network can then be extended via OTN to cover the 16 locations of this light rail line.

Signal ( RS485 )
The OTN RS485 card has 3 circuits and is compliant with the EIA-485 standard.

It can set to work either in the RS485 or RS422 mode and the data rates can be programmed between 1.2 kbps and 2 Mbps via OMS.

To realize this application, the OTN RS485 cards are installed at the OTN node of Control Center , 14 stations and Depot.