Procom VoIP - LCPU User Manual

Public Address over IP

on Train Station Platforms

DVS-21

VoIP - LCPU

Voice over IP - Application with the DVS-21 System

National sales by:

RSR Datacom GmbH & Co. KG

Alfredstrasse 157
D-45131 Essen

Tel.: [phone] - 0
Fax.: [phone] - 40
[e-mail]
www.rsr-datacom.de

Deutschland / Germany

A system that
speaks for itself.

International sales by:

ProCom
Professional Communication
& Service GmbH

Alfredstrasse 157
D-45131 Essen

Tel.: [phone] - 90
Fax.: [phone] - 98
[e-mail]

www.procom-communication.de

Features

The Basis Platform is the DVS-21

!

A modular concept, can be universally applied (PA, intercom, remote operation…),
stations can be cascaded, system has interfaces to transmission technology

Compatibility to Public Address System Requirements

!

Compliant to german railways specifications like "Public Address on Train Station Platforms",
equipment regulations "Public Address on Train Station Platforms" for equipment levels 1 and 2,
application description “Public Address Over IP Networks (VolP)"

Main Functions of IP Public Address

!

In addition to the general functionality of a public address system there are certain requirements
in the area of IP public address which require special solutions. The important requirements are
listed as follows:

- Standard communication protocol H.323 / SIP

- Automatic / manual selection

- Authentication / prioritizing
(Refusal) (Suppression)

- Voice delay less than 1 s

- Connection and call/session monitoring

- Connection: Keep-alive (Conforming to
Connection protocol)

Software, Voice over IP

!

Linux operating system, DVS-21 API (Application Programming Interface),
Application: VolP - LCPU (Voice over IP for LCPU)

LCPU Hardware

!

DVS-21 System Module 3HE / 6TE
Intel XScale PAX 255, 400 Mhz
64 MB SDRAM (32 bit @ 100 Mhz)
32 MB Flash Memory (32 bit), CF-card up to 2 GB
10/100 MBit Ethernet controller, RJ45 connection
Universal module connection (Attachment modules: SO, E1, RS232)

- Call/session: RTP monitoring
during an active connection

- Timeout: during an active connection

- Issuing of an advance signal before an
announcement

- Indication of message operation and errors
over SNMP trap

All rights and changes reserved V1.2

Public Address over IP

on Train Station Platforms

DVS-21

National sales by:

VoIP - LCPU

Voice Over IP Application with the DVS-21 System

General

Operational responsibility to carry out announcements with information and warnings for
travellers is being expanded in train stations and concentrated in public address centres.
This makes additional demands on the public address systems. Technically it has been
necessary here to provide additional interfaces for standard broadcasting systems in
addition to the interfaces already available in the communication system. Here the
standard is derived from a combination of the interface itself together with the utilized
communication protocols.
The objective here is to carry out an operational function, in this case public address,
over a standard network in a way that satisfies requirements and is sufficiently secure.

System Structure:

The VolP application runs as software application on the Linux operating system on the
DVS-21 LCPU system module. The LCPU, which directly integrates with the DVS-21
system bus, makes all DVS-21 functions available to VolP application over an API
interface. This way the VolP application is "aware" of the complete allocation and signal
situation in the entire system and can be combined with other DVS-21 applications
(e.g. digital public address system) on the LCPU.

RSR Datacom GmbH & Co. KG

Alfredstrasse 157
D-45131 Essen

Tel.: [phone] - 0
Fax.: [phone] - 40
[e-mail]
www.rsr-datacom.de

Deutschland / Germany

A system that
speaks for itself.

International sales by:

ProCom
Professional Communication
& Service GmbH

Alfredstrasse 157
D-45131 Essen

Tel.: [phone] - 90
Fax.: [phone] - 98
[e-mail]

www.procom-communication.de

System Components, Integration Capabilities:

Because the VolP application is fully integrated in the DVS-21 communication system all
of the benefits of the DVS-21 system are available to it. This includes:

- Public address in compliance with german railways equipment level 1

- DVS-21 system call stations

- DVS-21 system interfaces

- A wide range of interfaces to third party communication and transmission systems

Thanks to an open user interface the system can be individually and optimally adapted to
the user's operational processes with powerful user interfaces (e.g. monitor and
announcer workplaces, video workstations, and similar).

The consistently open system components used here, which are based on system levels
(user, switching and terminal device levels) as well as on open or standard interfaces,
allow both fully-new as well as partially-new communication systems to be realized which
allow the integration of existing ones.

Conformity

The DVS-21 system has a german railways type approval as public address system
based among other things on: "Specifications for Public Address on Train Station
Platforms" in the current version and the "Equipment Specifications for Public Address
on Train Station Platforms" in the current version, in compliance with the equipment
levels 1 and 2 (Reference no: 3095972/0/4) and is already in use in many kinds of
transportation stations.

All rights and changes reserved V1.2