Voice

ALERT features an embedded voice server as standard for accessing and disseminating alarms as voice messages.

The voice server welcomes called operators (or callers) with a greeting message that prompts them to confirm their identity by entering their PIN code. Signing in automatically acknowledges all the calls intended for the operator (standard calls or messages previously sent by SMS or pager). Users can then access and acknowledge their alarms, as well as listen to service messages and record voice reports (maintenance log).

ALERT also features an optional speech synthesis program for automatically converting text into voice messages, which spares users the effort of having to first manually record voice messages for the alarms. This module adds dynamic data (date, value, etc.) to their messages for even greater accuracy.

Drawing on the extensive expertise and track record that Micromedia International has forged in the telecommunications sector, ALERT is compatible with a wide range of communication channels for delivering your voice calls.

Public switched telephone network (PSTN)

The public switched telephone network may be sliding down the road towards obsolescence, but it is still prevalent and widely used in today's world after spending several years as the backbone for countless communication channels (telephone, videotex, pagers, fax, broadband Internet, etc.).

ALERT has always been capable of making voice calls over this longstanding telecommunications network, i.e.:

• Over analog lines using analog modems
• Over ISDN lines using ISDN modems

GSM network

ALERT can use a Micromedia SMS & Voice gateway (or a model on Micromedia's list of compatible modems) to send voice calls over the GSM network. With several countries going on record with their plans to switch off their PSTN networks, this solution represents an attractive solution, especially if you check out its list of advantages:

• The installation is agnostic of the client IT or telephone infrastructure

• It can be used to send SMS messages in addition to voice messages

• It improves the reliability of the installation by keeping an close eye on ALERT's performance and sending an SMS message in the event of a failure

VoIP

ALERT can make VoIP calls (voice over IP) for sending voice messages.

The main selling point with this technology is that it does not require any special hardware, only a simple connection to the computer network (IP). For the system to work, however, a private branch exchange (PABX/IP PBX) or an account with an external service provider is required that meets the following specifications:

• SIP protocol: RFC 3261
• Audio formats: G.711 µ-law and G.711 A-Law
• DTMF support: RFC 2833, SIP INFO 

Radio

Radio networks continue to be a popular means of communication at several industrial sites due to the technology's easy and cost-effective deployment and its wide-ranging coverage.

Depending on the radio base station, ALERT can send voice messages over walkie-talkies in different ways:

• Using conventional phone calls by interconnecting the radio base station with the site's telephone system.
• Using VoIP over radio base stations that are compatible with the protocol
• Using special modules for interconnecting with the radio base station and a proprietary IP communication protocol embedded in ALERT