White Paper by Commend International GmbH

Technology Guideline

Foreword

In a world dominated by constant technological progress we are all looking for ways to streamline our workflows and at the same time cut down on the growing expenses without sacrificing on security issues. This is where Commend Intercom comes in. A product, evolved from the very basic need of communication, Intercom solves everyday problems in a way no other solution can. Quick, efficient, secure and highly reliable (up to 99.998 % availability), Commend solutions prove to be an indispensable tool for a wide range of businesses and organisations worldwide. Backed up by the high level of quality and top-level support, we aim to provide a solution perfectly suiting your requirements. Because we at Commend believe that â&#x20AC;&#x17E;technology shall aid mankind, and not visa versaâ&#x20AC;&#x153;, you are now holding a document in your hands that should clarify all topics concerning our everyday high-tech environment. For the most basic of users to the skilled IT engineer.

Index TECHNOLOGY DETAILS 1. System Supervision 2. Speech 2.1. OpenDuplex® 2.2. Switched Duplex (or Voice switched Duplex) 2.3. Simplex 3. Call Handling 4. Intercom Architecture 4.1. Basic Intercom Topologies 5. Redundancy 6. Mobility 7. Security 8. System Integration 9. Interfaces 10. Access Control 11. Public Address (PA) 12. Building Management Systems (BMS) 13. Standards and Legislation 14. Compatibility 15. Intercom Protocols 15.1. From Analog Speech to Digital Voice Packets 15.2. Intercom Voice Coding 15.3. Conversion of audio formats in the DSP 15.4. DSP Voice Compression: G.711 alaw Codec 15.5. DSP Voice Compression: G.722 Codec 15.6. IoIP® Voice Packet Assembly / IP Interface 15.7. Protocol Model – Intercom Server Links 15.8. Protocol Model – Intercom Station Links 15.9. IoIP® Protocol Specifications 15.10. IoIP® Traffic Behaviour 15.11. IoIP® Single Port Protocol Header 15.12. IoIP® Data Encapsulation 15.13. Jitter Buffer for IoIP® Audio Packets 16. Quality of Service (QoS) 17. SIP & IAX 18. IoIP® vs VoIP 19. Bandwidth requirements 20. Audio Monitoring (Scream Alarm) 21. Hands-free 22. Control Desk 23. Challenging Situations 24. Loudspeaker / Microphone Surveillance

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6 6 7 7 10 13 13 13 13 14 14 14 15 16 16 16 17 17 18 18 19 19 20 20 21 21 22 22 23 23 23 24 25 26 26 26 27 30

Commend International GmbH · Saalachstrasse 51 · A - 5020 Salzburg · Tel. + 4 3 - 6 62- 85 62 25 · Fax + 4 3 - 6 62 85 62 26 · office @ commend.com Version 1.0/0109 | Errors and omissions excepted | Products may change in the interest of technical improvements without notice.

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TeCHnOLOGY deTAILS 1. System Supervision 2. Speech “Speech quality is a major contributor to the telecommunication user’s perception of quality of service. As communications networks become more heterogeneous, identifying the root cause of voice quality problems can be a challenging task. The evaluation and assurance of speech quality has, consequently, become critically important.” Ieee Signal Processing Letters Providing connections for the transmission of audio/speech signals is still a core function of any Intercom station, even as the functionalities grow with the addition of advanced features such as live video imaging, building management (see section on Building Management) or access control (see section on Access Control). obviously, a clear, uninterrupted high-quality speech signal is absolutely essential in modern intercoms, which are frequently relied on in situations where literally every word counts (see section Challenging Situations). Intercoms such as Commend’s Intercom 2.0 range therefore offer much higher audio/ speech quality and reliability compared to applications such as mobile or Internet telephony. From analogue to digital In Intercom systems, the audio signals can be transferred either via analogue (4-wire) or digital (2-wire, IP) connections (→ see section on Intercom Architecture). Commend Intercoms support both types of connections to suit any given infrastructure. Digital connections have the added benefit of opening up the world of Intercom 2.0 – with features that include web portability, real-time signal processing, digital and wireless networking, etc. Measurable speech quality In audio communication, it is the sampling rate (comparable in a graphic image to the image’s resolution/granularity) that determines the quality of the speech signal output. The higher the sampling rate, the clearer the signal becomes, which makes it easier to distinguish speech sounds from ambient noise (an issue that users of mobile phones, for example, are only too familiar with). Depending on the configuration employed, Commend Intercom 2.0 stations offer up to 16 kHz Hd audio, which is the highest Intercom audio quality available and by far superior to regular telephony applications, which typically operate at around 3.4 kHz.

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TeCHnOLOGY deTAILS Audio modes Intercom Stations support three basic audio modes: • • •

Simplex operation (PTT = Push to Talk): allows for manual control of the communication direction; a button must be pressed before speaking Switched Duplex operation: detects and switches the communication direction automatically OpenDuplex® operation: maintains open communication lines in both directions to allow for natural, fully hands-free conversations.

Commend’s OpenDuplex® technology includes a powerful echo cancellation algorithm to improve speech quality by eliminating interfering noise at high volume levels, even in 16 kHz high-definition audio quality.

2.1.OpenDuplex® This is the newest type of speech control incorporating a state-of-the-art dSP computer chip that allows simultaneous talking and listening and at the same time filters out background noise to provide top quality speech intelligibility. ECHO CANCELLOR

• • • •

ECHO CANCELLOR

The conversation is permanently switched through in both directions, therefore both conversation partners can speak simultaneously The OpenDuplex® mode allows an improvement in speech quality at high ambient noise levels OpenDuplex® is carried out by echo Cancelling in the dSP Should not be confused with Full-Duplex which is similar but without echo cancelling and so only works correctly when one side is using a gooseneck microphone or headset

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TeCHnOLOGY deTAILS 2.2. Switched Duplex (or Voice switched Duplex) With this type of speech control, a duplex controller (a computer chip) controls the direction of speech. only one person can speak at a time.

Duplex Controller

• Speech communication in both directions, in which the louder sound source (usually the speaking person) determines the direction of the speech connection. This means the loudest side speaks and the other listens. • Perfect intelligibility up to a distance of 7 meters from the station, without pressing a button – the distance depends on the ambient noise • The speech direction is determined by the “speech balance” (duplex controller)

2.3. Simplex This is the earliest type of speech control where the speech direction is controlled manually. only one person can speak at a time.

• • •

Speech communication only in one direction that is controlled by pressing the talk button. Also known as press-to-talk, release to listen. Simplex is used for manual speech control, e.g. areas with high ambient noise Possible configuration: • Conversations fixed Simplex (the speech direction after initiating a conversation can be defined) • Simplex by pressing a button (the button must be held down to talk and released to listen) • Simplex by momentarily pressing a button. The other person must press the button to reverse speech direction.

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TECHNOLOGY DETAILS 3. Call Handling The major advantage of Intercom systems compared to telephone systems is the capability of storing and processing calls and events (inputs, outputs) in a sequence defined by the user. This can be critical, e.g. in emergency situations, when the operator presses a wrong button due to stress the call can be picked up again from the call list. In contrary telephone systems usually use the more common first-in-first-out queuing. An intercom station configured as central control station can, in addition to the normal intercom features, perform the following functions: • Call Requests from other intercom stations: If a configured call button at an intercom station is pressed, this call is stored and indicated at the central control station. The call has to be taken over at the central control station by pressing a button, then a conversation is built up. Depending on the configuration, two different types of call requests can be initiated: • Call 1 (equivalent to a “normal call”) • Call 2 (equivalent to an “emergency call” In addition, line faults of intercom stations can be indicated at central control stations. • Input messages: Activated inputs can be stored and indicated at a central control station. An input message is acknowledged at the central control station by pressing a button. Depending on the configuration and cabling of the inputs, 5 different switch steps can be indicated: • Idle mode • Active 1 (equivalent to a “normal call”) • Active 2 (equivalent to an “emergency call”) • Short circuit • Line break

4. Intercom Architecture “What were once just simple point-to-point voice communications devices have grown over the last two decades into major communications networks and large installations. This evolution of intercom systems also brought about a change in perspective. While it used to be good enough to just provide a simple communications link between two or more users, nowadays, several different data and signal types need to be integrated into an overall network. [...] Installations are getting increasingly complex, demanding new approaches and new solutions that [...] link together multiple production locations simultaneously.” Broadcast Engineering (December 2009 issue)

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TECHNOLOGY DETAILS In the days of Web 2.0, Intercom solutions have long outgrown the image of the single-line, single-button door buzzer panel. In a wide range of communication and building management settings, Commend’s Intercom 2.0 is emerging as the future central hub technology that brings together everything from audio and video communication to building security, door access, parking and facility maintenance. Behind this versatility lies a powerful technical architecture that serves and co-ordinates the three key functionalities of modern Intercom applications: 1. 2. 3.

reliable point-to-point audio/video communication connections; building management and control functionalities; and back-office management and system administration

Market requirements on contemporary intercom systems are as varied as the environments in which they are used. Commend solutions are designed to accommodate a wide range of different system topologies and installation sizes. This is made possible by an essentially modular system structure on virtually every level. Intercom components, communication channels and network links can be arranged into various layouts (typologies), depending on the overall scope and individual requirements (e.g., performance, need to integrate existing equipment, etc.).

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TECHNOLOGY DETAILS Levels of Intercom functionality (in order of complexity) Equipment/Solution

Functionality

Example(s)

Single-button call station

Initiating calls to a pre-set recipient

Single-button help/emergency call stations (e.g. roadside help points)

Keypad-equipped call station

Initiating and receiving calls within a network of call stations

Office Intercom arrangements; e.g. Commend desktop stations or WS Series wall-mount stations

Control desk solution

Handling and automating two-way connections; controlling (forwarding, redirecting, scheduling ...) and monitoring communication connections and handling integrated building management (security alarms, lifts, …) ((link: BMS ))

Reception desk control stations for office buildings; central control stations in transport, infrastructure, healthcare and industrial environments.

GUI-controlled integrated solution

Full control of all communication and control functions (including integrated third-party systems/components) from a central workstation via operating software with on-screen graphic interface. Provides clear overview, maximum operational transparency, full control, reporting, automation, and many other features and capabilities.

Control rooms, central workstations in various industrial, commercial and institutional environments, with integrated third-party systems and communication channels (mobile telecom and data networks, RF transceivers, Building Management Systems, etc.); e.g. Commend ComWIN.

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WAN

TECHNOLOGY DETAILS 4.1. Basic Intercom Topologies Star Topology Description

Call and control stations are connected to one central Intercom Server.

Application

(( Simple, smaller sized communication solutions for offices, loading docks, etc. that do not require high bandwidth. ))

Benefits / Disadvanteges

Cost-efficient and easy to plan and implement, although scaling up may require some effort (cabling).

WAN WA N

(( → + all tech benefits, extras, etc.))

Bus Topology Description

Several star type networkes connected (trunked) together. Extra 4-wire cabling enhances bandwidth between Intercom Servers

Application

Communication solutions for offices, loading docks, etc.

Benefits / Disadvant

Same as star topology, but easier to scale up. (( Benefits GE 800 etc. – multi-card support etc.: several servers in 1 unit, etc. )) (( Extra components available 4 integration ))

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TECHNOLOGY DETAILS Ring Topology Description

Call and control stations are all connected into a dual fibre ring.

Application

Sophisticated, highly reliable command/control and communication solutions for all types of indoor and outdoor applications: Building Itercom, Medical Itercom, Traffic Intercom, Prison....

WAN WA N Benefits / Disadvant

WAN

High availability (redundancy); even in large-scale installations (where cabling requirements can grow exponentially with installation scope), cabling efforts are kept to a bare minimum. Supports numerous variations and combinations of arrangements/configurations, equipment and optional extras to meet most any customer need.

Meshed Topology Description

Highly reliable layout where all Intercom Servers are interconnected.

Application

Communication and control solutions for applications requiring high availability, comprehensive functionality and (central) control: Prison Intercom, Medical Intercom, Office Intercom, etc.

Benefits / Disadvant

WAN WA N

High reliability, as interconneceted fallback servers can take over in case of link loss.

(( Extra components/modules available 4 integration)

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TECHNOLOGY DETAILS Connectivity Apart from networking and system topology, connectivity is a central factor to consider in intercom installations. Two key aspects need to be taken into account in this regard: the types of transmission signals to be used, and the way they are transmitted (i.e., the transmission protocols used). There are several influencing factors that govern the choice of signal technology and protocols. Installations today typically involve more than just speech signals and increasingly need to integrate digital signal technologies for IP-based communication and control functions. This means the systems must support signals of different types and densities (e.g. G.711, G.722, ...), resulting in specific bandwidth requirements. An Intercom solution‘s ability to handle combinations of analogue and digital signals is therefore an essential indicator of its quality and readiness for future applications. Commend solutions come fully prepared for the integration of various types of signals (e.g. e.g. G.711, G.722, ...) and protocols (e.g. SIP, IAX). This ensures a large degree of flexibility when it comes to integrating existing systems and infrastructures. Frequently, real-time audio and video channels need to be combined with IP-based communications into single integrated networks that can be managed from a central control station. For this purpose, Commend solutions provide merged Time-Division Multiplexing (TDM) / IP support. This offers the best of both worlds: reliable high-quality on-site communication that does not tolerate latency (e.g., Medical Intercom, help points) as well as networking over virtually unlimited distances using IP connections, including the Internet. Intercom architecture of the future With the introduction of Intercom 2.0, Commend has already taken a big step into the future of the ever more versatile world of Intercom. Integrating digital party-line communications with industrial radio communication, building management and and wireless solutions, Intercom 2.0 has laid the foundations for serving an ever more demanding and quality-conscious market well into the future. This integration is essential to allow individual solution components to be combined and adapted to individual needs without the need for costly one-off developments and adaptations. However, alongside the need for integration there arises the need to keep this easy and manageable for users and system operators alike. Controls must be easy and intuitive to operate within seconds, even by someone who has never done so before. At the same time, supporting system software must put full communication and control functionalities at the operator‘s fingertips without getting cluttered or complicated. In view of these needs, usability and ergonomics provide crucial product development guidelines for new-generation solution ranges such as Intercom 2.0, as its motto “Simplicity meets power” suggests.

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TECHNOLOGY DETAILS 5. Redundancy “Backups are […] insurance. Not having a backup is a frightening prospect.” (SmartComputing.com) It’s a basic rule of life in a largely unpredictable world that even the best technology is subject to the occasional malfunction. As a result, backup structures are an essential part of any IT-based system. Doing so makes good business sense. But with security-critical applications such as Intercom, the stakes are much higher, as human lives frequently depend on it. In these cases, the usual backup strategies won’t do. Because every single word counts in critical situations, Commend Intercom solutions are designed to make sure the message (or control signal) gets through under any circumstances. This is why Security Intercom solutions come packed with a range of extra redundancy features to ensure full, all-year, round-the-clock fail safety: •

Redundant connections mean that in case the connection is down, connections will automatically be re-routed through independent standby lines (often of a different transmission technology) to sustain connectivity even in case of a network failure. • Redundant, independent power supply means that the entire system can be powered independently in case of a blackout or emergency to sustain all essential communication and control functions. • Redundancy ensures compliance with high availability standards

6. Mobility 7. Security 8. System Integration Economic and technical efficiency require modern Intercom solutions to be open to the integration of third-party solutions such as building/facility management systems (>> see section on “Building Management”), door/gate access control solutions, public address systems, mobile radio transmitters, and many others. This is to eliminate redundancies, they first and foremost help to cut costs in terms of investment and overheads. So far, the most efficient way to achieve this is to build Intercom systems on a modular basis that allows individual functional models to be added or replaced as needed. In addition to that, Intercom 2.0 provides open, programmable interfaces that allow individual functional models such as door control – and even entire third-party systems such as public address setups – to be ‘pugged into’ the basic Intercom system. See also Building Management Systems (BMS)

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TECHNOLOGY DETAILS 9. Interfaces 10. Access Control “Access management is not just essential to workplace efficiency - it’s also key to cutting IT enterprise costs and delivering value beyond security and compliance services.” (Gartner Group, 2009) Automated access control provides the system mechanism by which personal access is granted to facilities (buildings, venues, etc.). An essential requirement in both commercial and non-commercial business environments., controlled access helps to protect assets, prevent unauthorised entry, and ensure transparency and security (e.g. through systematic ingress/egress logs). Access control systems consist of three key elements: • a (smart) means of identification (e.g., tag or smartcard) • physical access equipment (door, gate, turnstile or similar), and • a software application to manage access permissions and monitor access transactions Commend provides the add-on access control package ComACCESS, which integrates seamlessly into the Intercom 2.0 server environment to provide an all-in-one solution for all Intercom and access control needs. This creates a ‘naturally’ integrated application environment for the two functions (e.g. at office buildings, industrial premises or prisons). All this comes with obvious benefits for the operator: it eliminates the need for a separate access system, which cuts investment and running costs. Also, the native integration into the Commend Intercom environment makes for smooth, trouble-free operation and reduced service/maintenance costs as a result. How does it work? ComACCESS provides powerful functions for managing a virtually unlimited number of users (permit holders). Permits are issued in the form of wireless smart tags, which can each be programmed with individual access permissions to specific areas, at specified times, etc. All that’s needed to gain access at a door, gate or turnstile is to hold up the tag to the scanning point on the Intercom panel.

11. Public Address (PA)

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TECHNOLOGY DETAILS 12. Building Management Systems (BMS) BMS is short for “Building Management System”. Basically, it is a computer based system with hardware and software that can monitor and control a wide variety of systems installed in a building or complex. Systems that can be monitored include heating, ventilation, power, fire alarms, intercoms located at doors, gates, barriers, plant rooms and lifts; security systems like access control, intruder detection, CCTV, lifts and escalators, gas detection systems and environmental control systems like external blinds, internal lighting and many other such systems. ComWIN by Commend is a high level BMS integrationsolution. It provides a user friendly graphical representation (Graphic User Interface or GUI) of the building or complex and can be tailored to a customer’s specific requirements. Multi-layer screens show the location and status, and allow control of, doors, gates, barriers, alarms, indicators etc. ComWIN applications range from simple, single user to multi-user and even multi-site solutions and are 100% compatible with all Commend equipment. ComWIN can also integrate seamlessly with other manufactures’ equipment via Commend’s configurable Inputs and Outputs and its flexible, open-protocol and bi-directional data interfaces. ComWIN, ComReporter, ComScheduler and ComVideo provide you with full graphic control of your various systems from a PC screen. The functions which most often apply in these applications are to form one single overriding building management system: • • •

Combining of security facilities e.g. fire and intruder alarms, CCTV, door, barrier management and access monitoring systems Communication systems e.g. “master” and “slave” speech units, lift intercoms, mobile radios, pagers, telephones, printers etc. And medical and emergency equipment such as lift control systems, lighting, ventilation and heating

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TeCHnOLOGY deTAILS

GATEWAY

EIB-BUS

ComACCESS SERVER

IP-LAN

L A R

NET

IP-LAN

WAN PSTN

13. Standards and Legislation >> in preparation Medical IP 54 dust, spray water IK 07 vandal resistance

14. Compatibility The IP-Intercom Servers flexibly adapt to your specific project requirements and are compatible with previous system generations. All IP, digital and analogue stations of Commend manufactured as long ago as 1980 can be connected to the IP-Intercom Servers GE 800 and Ge 300, as well as SIP Servers and SIP and analogue telephones.

15. Intercom Protocols The following section contains an overview of the protocols, compression methods and other technical details which can get quite complex. They are aimed mainly as information for IT-enginieers as aid when integrating or setting up a new system for Intercom.

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TeCHnOLOGY deTAILS 15.1. From Analog Speech to Digital Voice Packets Commend voice digitalization principle:

15.2. Intercom Voice Coding 16 Bit linear Pulse Code Modulation (PCM) in the Codec:

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TeCHnOLOGY deTAILS 15.3. Conversion of audio formats in the dSP GE200/700, DSP800, DSP900: •

Linear quantized bit stream from the Intercom codec (16kHz sampling frequency, 16 bit words)

•

DSP: Conversion of byte-stream into configurable audio format: • down-sampling to 3.4kHz audio bandwidth, conversion to G.711 alaw • Conversion for 7kHz audio bandwidth (2 x G.711 alaw) • G.722 compression for 7kHz audio bandwidth

GE300/800, DSP800A, DSP900A: •

Linear quantized bit stream from the Intercom codec (32kHz sampling frequency, 16 bit words)

•

DSP: Conversion of byte-stream into configurable audio format: • down-sampling to 3.4kHz audio bandwidth, conversion G.711 alaw • Down-sampling to 7kHz audio bandwidth, conversion 2 x G.711 alaw • G.722 compression for 7kHz audio bandwidth • 2 x G.722 compression for 14kHz audio bandwidth

15.4. DSP Voice Compression: G.711 alaw Codec • • • •

ITU standard codec for 3.4kHz audio bandwidth 16 bit words are converted into 8 bit words (Bytes) Non-linear quantization: more detailled resolution of low amplitudes, coarser resolution for high amplitudes Differentiation alaw (13 bit resolution) and µlaw (14 bit resolution): minimal differences in the quantization characteristic curve

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TeCHnOLOGY deTAILS 15.5. DSP Voice Compression: G.722 Codec ITU standard codec that provides 7 kHz wideband audio Split band ADPCM (Adaptive Differential Pulse Code Modulation):

15.6. IoIP® Voice Packet Assembly / IP Interface

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TeCHnOLOGY deTAILS 15.7.

Protocol Model – Intercom Server Links

15.8. Protocol Model – Intercom Station Links

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TeCHnOLOGY deTAILS 15.9. IoIP® Protocol Specifications IoIP® Voice packets • • • • • •

Constant bit- and frame rate stream: 1 voice packet every 16ms / channel UdP protocol without re-transmission; sequence numbers for re-ordering Adaptive Jitter Buffer for incoming voice streams Bandwidth per channel: G.722 coding: 82kbps (including IP header) Commend G.711 coding: 143kbps (including IP header)

IoIP® Data packets (signalling) • • • •

Commend signalling protocol (setup and manage any kind of features) Variable bit- and frame rate: depending on configuration and activity re-transmission algorithm similar to TCP Configurable traffic shaping algorithm to avoid traffic peaks

IoIP® Idle packets (link monitoring) Used for link polling and data packet acknowledgement

15.10. IoIP® Traffic Behaviour Audio and signalling data (LAN/WAN cards) • •

Constant and calculable bit rate for voice Variable bit rate –> limitation by using traffic shaping

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TeCHnOLOGY deTAILS 15.11. IoIP® Single Port Protocol Header

15.12. IoIP® data encapsulation Data encapsulation: • • •

OSI layer 2 – Ethernet: OSI layer 3 – IP: OSI layer 4 – UDP:

“Data Frames” including at least 14 bytes “IP Packets” including 20 bytes IP header 8 bytes UDP header including port numbers

• •

IoIP® header: IoIP® payload: • Voice packets:

8 bytes including type (data, voice, idle)

•

Data packets:

128 bytes (G.722 compression) 256 bytes (Commend G.711 codec, 2x G.722) max. 96 bytes

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TeCHnOLOGY deTAILS 15.13. Jitter Buffer for IoIP® Audio Packets

16. Quality of Service (QoS) “In the field of computer networking and other packet-switched telecommunication networks, the traffic engineering term quality of service (QoS) refers to resource reservation control mechanisms rather than the achieved service quality. Quality of service is the ability to provide different priority to different applications, users, or data flows, or to guarantee a certain level of performance to a data flow. For example, a required bit rate, delay, jitter, packet dropping probability and/or bit error rate may be guaranteed. Quality of service guarantees are important if the network capacity is insufficient, especially for real-time streaming multimedia applications such as voice over IP, online games and IP-TV, since these often require fixed bit rate and are delay sensitive, and in networks where the capacity is a limited resource, for example in cellular data communication.” (wikipedia)

17. SIP & IAX

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TECHNOLOGY DETAILS 18. IoIP® vs VoIP “In October 1998, Cisco announced that it was acquiring Selsius, a manufacturer of packetbased phone systems. That signaled the beginning of a new era in how we think about the use of our IP networks. Now, we routinely think of the transfer of voice, data, image, and video over these networks. It‘s no surprise that the intercom system is using the IP network.” (AV Technology Online) The convergence of network-based data and telecom technologies reached the telephony and related markets, giving rise to protocol standards like Voice over IP (VoIP) for transmitting speech signals over IP (Internet Protocol) networks. Now an integral part of the social “Web 2.0” experience, VoIP communication enjoys great popularity within the social networking community. As the above quotation suggests, IP-based networking holds very obvious advantages for both professional security and communication. IP networks are ubiquitous: every office is connected, as are most production and service facilities. Down to the last piece of equipment, setting up an IP connection is no longer a problem. However, it‘s modern server-based Intercom systems with their complex control and communication functions that expose where VoIP has its limits, both in quality and reliability. That is why Commend solutions make use of a much more advanced IP protocol, which was developed specifically to meet the needs of professional security and communication: Intercom over IP (IoIP®). Commend Intercom terminals or stations can easily be plugged into convergent corporate IP networks and interlinked via an Intercom Server. Data streams of external systems (such as Building Management Systems; see Section 12) are integrated into the Intercom system for monitoring, evaluation and control purposes -- all via IoIP®. At the same time, speech signals can be transmitted at a level of quality and reliability that VoIP users could only dream of (see Section 2 “Speech”). Practical application IoIP® integrates seamlessly with both 2-wire and 4-wire technologies, which makes it universally suitable for any Intercom application. It provides a technically and commercially ideal basis for making use of Intercom Terminals, even in locations where this used to be impossible due to cabling and cost limitations. Some of the typical applications where IoIP® ensures high-level communication and security include, among many others: • Remote doors and gates (also via Wireless LAN connections) • Offices and administrative facilities (speaker terminals connect to existing IP network) • Help points, remote sites, elevators, barrier gates and ticket vending machines at car parks

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TECHNOLOGY DETAILS Where is IoIP® going? Clearly, speech transmission remains a key function of any professional Intercom solution. With its 16 kHz technology, Commend has introduced the highest industry quality standard. However, Intercom already means much more than just that - and it’s set to grow with market demands and technical advancements. With high-bandwidth connections now the norm, the transmission of video images is gaining in importance, spurred also by an increasing demand in security. Serving this demand are also emerging Intercom System functionalities for event recording and messaging, and the controlling and monitoring of security and communication processes. Commend systems already provide full support of all these needs and will continue to be developed to meet future requirements, whatever they may be.

19. Bandwidth requirements IP-networks are limited by a certain bandwidth they can transmit. This is the measure of the amount of data that can be transmitted (expressed in bit/s - usually kbit/s, Mbit/s etc.). Every application in an IP-network requires a certain bandwidth. In networks which are shared by various applications (such as video, audio, access control) it is important to regulate the data flow. Especially voice but also video applications depend on continuous and guaranteed data streams for quality transmission - see also QoS. Depending on which audio codec is configured, the Commend Intercom System requires the following bandwidth per audio channel (including the IP and IoIP® header): a. 3.4 kHz audio (G.711/8 codec): 82 kBps b. 7 kHz audio (G.711/16 codec): 146 kBps c. 7 kHz audio (G.722/16 codec): 82 kBps d. 16 kHz audio (G.722/32 codec): 146 kBps In addition to audio transmission, signalling requires a certain amount of bandwidth. A single IP-Intercom Station should have at least 14 kbps reserved for signalling. Trunk links between Intercom Servers should provide at least a total bandwidth of 128 kBps (one audio channel plus signalling). All network interface cards of the Commend System provide a built-in traffic shaping algorithm, to avoid packet bursts in case of broadcasts applications like alarm features or paging (group calls). Every IoIP® link is constantly monitored by exchanging idle packets. The idle-packet length of 36 bytes results in a traffic volume for one IP Station during one day of merely 104 kBytes.

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TECHNOLOGY DETAILS 20. Audio Monitoring (Scream Alarm) In certain situations the people in need of help do not have the possibility to physically touch an Intercom terminal. Imagine an in-patient in a hospital shouting for help or a woman in distress in a parking garage, someone being attacked in an elevator or a prison officer being confronted by an inmate. To cater for these situations, Intercom systems from Commend provide a feature called Audio Monitoring. It permanently monitors the volume at an Intercom terminal and automatically initiates a call to the control desk as soon as a pre-defined volume is exceeded. The personnel at the control desk can then quickly initiate a call to the station. A video picture can be automatically switched on for an additional overview of the situation.

21. Hands-free Hands-free is an adjective describing equipment that can be used without the use of hands (for example via voice commands) or, in a wider sense, equipment which needs only limited use of hands, or for which the controls are positioned so that the hands are able to occupy themselves with another task (such as driving) without needing to hunt far afield for the controls. (wikipedia) There are situations where hands free technology is indispensable (such as in a operating theatre) or just simply very useful (in offices or dental surgeries). It allows a much more natural form of communication, as if the communication partner was right next to you. Therefore it is easier to concentrate on the conversation, which is essential in critical situations. The main acoustic issues are echo cancellation and noise suppression, although there are others as well. Commend’s hands-free speech technology is a far cry from what is used in mobile or desktop phones. A speaking distance of up to 7 meters (21 feet) is a result of using the best possible quality microphones and loudspeakers combined with Commend’s own echo cancelling and noise reduction software.

22. Control Desk

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TECHNOLOGY DETAILS 23. Challenging Situations “The proof of a product is in its performance” - Unknown (every good product developer, actually) Situation 1: Intercom in traffic environments Tunnels, garages, toll stations and open roads are application environments that impose highly specialised and stringent requirements on Intercom solutions. Challenge

Intercom 2.0 Solution

Traffic noise

16 kHz signal technology (>> see “Speech”) High-definition audio signal makes voice clearly distinguishable from background noise

Connection interference, interruptions (e.g. in tunnels, garages)

Dedicated high-quality components Off-the-shelf equipment is insufficient Multi-level fail-safety concepts e.g. Distributed Card Intelligence (>> see “Redundancy”)

High-volume call handling (e.g., public transport facilities at peak times)

Intelligent call handling Dynamic call management, e.g. with call buffering, which supports staff co-ordination and ensures that callers are never confronted with a busy signal

Operators’ and help providers’ need for immediate assessment of distress situations

Full real-time video/CCTV support Enhances audio-only communication to make it more personal and immediate; also provides valuable visual feedback to helpers and security staff

Weather, corrosion, vandalism

Sturdy, water-/weatherproof and vandal-resistant design All outdoor components (call stations, loudspeakers, etc.) are protected against ambient influences

Public address functionality and facility management (e.g., signage, lifts, gates, etc.)

Open system structure that integrates smoothly with third-party PA systems, building/facility management systems (>> see “Building Management System”) , etc. This is complemented by special features, e.g. the transmission of public announcements to motorists’ car radios in high-noise environments such as tunnels or parking garages (see ‘traffic noise’ challenge above).

Central control of multiple facilities

Centralisation support This enables full monitoring and control of all linked facilities and equipment from a central control desk.

Support of advertising and user information

Advanced technologies E.g., automated/scheduled playback of pre-recorded promotional or informational messages at call stations; transmission of customer/passenger information via induction loop amplifiers, etc.

Economic efficiency

Evergreen Engineering philosophy Stands for an extended product lifecycle, resourcesaving product design, and long-term system backward compatibility.

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TECHNOLOGY DETAILS Situation 2: Intercom in hospitals, trauma wards and healthcare environments Challenge

Intercom 2.0 Solution

Uniform, consistent and co-ordinated communication between medical staff, administrators and caregivers

Fully integrated Intercom Consolidates various communication channels on a single control desk for co-ordinated switching/patching, transfer etc. Various telecom technologies supported: mobile phones, desktop and wall-mounted call stations, RF communication systems (paramedics/police/rescue forces), etc. Complemented by built-in video support and integration of public address systems

Stringent hygiene and safety requirements

Full standards/regulations compliance Full support of applicable IP standards and EN directives for equipment in medical and healthcare environments, e.g., water and dust proofness, hygienic and antiseptic qualities

Facility management

Fully integrated building/facility management Centralised control of interlinked facility equipment (lifts, alarms, security doors, etc.); integrated staff/visitor access control and parking

Situation 3: Intercom on university campuses Challenge

Intercom 2.0 Solution

Reliable, well-co-ordinated staff communication across offices

Office Intercom platform with desktop and wall-mount call stations relayed to a central control desk and powered by proven Commend Intercom Server technology; full feature support for intelligent call transfer/ patching, notification, conference calls, etc.. Help points with extra high availability Fast, reliable connections to the campus security control desk for instant help when and where it‘s needed. Handicapped support Call points with enhanced usability and intuitive control; use of supportive innovative technologies, e.g. induction loop amplifiers for wireless transmission of calls and PA announcements directly to hearing aids

Access control and staff/student parking

ComACCESS system extension Enables fully integrated access control and rights management for controlled admission to staff and student car parks and door access on the university premises; centralised monitoring and control of multiple buildings; external parking management systems can be integrated via open programmable interfaces.

Centralised management of multiple buildings and facilities

Comprehensive facility management integration Extended integrated facility/building management with links to various on-campus facilities and equipment (security gates, lighting, signage, CCTV, lifts, alarms, public address system, etc.).

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TECHNOLOGY DETAILS Situation 4: Intercom for mountain resorts Challenge

Intercom 2.0 Solution

Need for reliable help/distress communication for skiers and hikers in mountainous environments (no IT infrastructures, no or bad mobile telecom support)

Help call points in the form of programmable Wireless Intercom call stations: no need for wire-based network infrastructures, as signals can be transmitted reliably over 500 m (line-of-sight) to Intercom receiver station. This helps to overcome terrain restrictions and saves on installation and running costs. Wireless call stations have the added benefit of being easy to move as and when needed.

Extreme outdoor weather conditions

Durable, weatherproof design Call stations based on weather resistant product design that withstands extreme temperatures and climate fluctuations, humidity and precipitation, long-term sun exposure and corrosion. Full protection of electronic assemblies and technical components from forceful impact and vandalism.

Situation 5: Intercom in high-security areas and detention facilities Challenge

Intercom 2.0 Solution

Control of high-security facility equipment (security doors, airlocks, alarms, etc.)

Flexible facility management with control room concepts for security section monitoring; central control station with graphic user interface for easy control and instant response in emergency situations. Integrated admission control/monitoring and access rights management for staff and visitors.

Controlled communication in sensitive areas (high-security areas, detention cells, etc.)

Extended Intercom functionalities Mobile phone detection, integrated radio reception for wall-mounted Intercom stations (e.g. for in-cell radio reception); comprehensive video/ CCTV monitoring support.

Secure staff and visitor communication

Secure Intercom networking with smooth integration of telecommunication technologies (UMTS, Blackberry): helps to reduce installation requirements (no need for extra systems).

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TECHNOLOGY DETAILS 24. Loudspeaker / Microphone Surveillance To guarantee the permanent functionality of an Intercom terminal it is not enough to monitor just the connection from the Intercom Server to the terminal. Moreover a continuous check of the “audio path” of the Intercom Terminal and its components (loudspeaker, microphone etc.) must be carried out. Loudspeaker / Microphone Surveillance is a feature provided by the Commend Intercom Terminals, which puts out an audio signal via the Intercom terminals loudspeaker which is immediately “heard” and analysed by the microphone. The DSP in the station then compares the received signal to the original signal sent out via the loudspeaker. If either of the components is impaired (e.g. chewing gum on microphone, loudspeaker wet or damaged), the DSP recognizes the defect and sends a message to the control desk. The control desk can then send maintenance to check and repair the station.

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glossary of terms Analogue / 4-wire Technology The transmission of the audio signal between Intercom server and Intercom stations is analogue over 4 wires (2 wires for the microphone signal, 2 wires for the loudspeaker signal). It is possible to superpose digital data, e.g. display information, dialling information, etc. Subject to disturbances when long cables are used and costly for cabling. Asterisk® Asterisk® is the world’s leading open source telephony engine and tool kit. Offering flexibility unheard of in the world of proprietary communications, Asterisk® empowers developers and integrators to create advanced communication solutions… for free. ATA An Analogue Telephone Adapter (ATA) is a device used to connect common analogue telephones to a digital telephone system like VoIP. Bus-Cabling Topology in which all systems are supplied with data from a bus. Offers easy cabling, however problems with the bus can cause all connected units to fail. See → star-cabling. Call-Request Request for a conversation where the conversation is only established when the call-request was accepted by the called station. A → control desk station can accept and handle several call-requests at a time. Close-up Microphone Microphone that records sound from close-up (ideal distance 5 cm) and neglects noise from greater distances (e.g. ambient noise). Ideal for noisy environments. Codec A codec is a software part which compresses or decompresses digitalized voice (or video) so it can fit through a limited communication channel such as a dial-up Internet connection. Command Stations Master station with gooseneck microphone, frequently used in control rooms. Communication Server → Intercom server Connection Linking of Intercom servers, e.g. via a tieline (line-connection over 2 or 4 wires), where not all functionalities of the Intercom servers connected are available. Programming and / or maintenance for each Intercom server connected can take place separately and locally. Control Desk Command station that also integrates various control functionalities. E.g. display of messages, switching of outputs, etc. Control desks are usually used in control rooms, often together with a visualisation software on a control desk PC (GUI – graphic user interface).

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glossary of terms Control Desk Visualisation Special visualisation software for a control desk PC which shows all functionalities of the control desk in a very clear manner on plans and where the functionalities can be controlled using a mouse. Additional functionalities can include: action plans, help text, etc. Control Desk Station Intercom station in a control-desk. Typically part of the control desk system, when using a control desk software (GUI) it is a simple master station next to the PC. Control Desk System Modular control desk, where all control and reporting functionalities are done with individual displays and function buttons. Control desk systems allow easy display and control on a uniform user interface. Conversations Speech communication between two Intercom stations. Digital / 2-wire technology The transmission of the audio signal between Intercom server and Intercom stations is digital, the A/D resp. D/A converter is in the Intercom station. Digital audio transmission is the basic requirement for networking Intercom systems. When using analogue Intercom stations a channel card is needed to digitise the analogue signal. DNS The Domain Name System (DNS) translates between host names (e.g. www.commend.com) and their corresponding IP addresses and vice versa. Door Call Call-request coming from a door station. DSP Digital Signal Processor: a micro-processor treating audio data in a digital manner. In Intercom systems a DSP can be used for new functionalities like Audio Monitoring or loudspeaker microphone surveillance and it enables OpenDuplex®. Duplex Communication where the duplex-controller automatically switches the speech direction from the speaker to the listener (from the louder to the softer side). Loud background noise influences this speech control so that the speech direction must be controlled manually (PTT – push to talk, see → Simplex). A perfect solution is → OpenDuplex®. Duplex Controller Circuit used in duplex mode to switch the speech direction from the speaker to the listener (from the louder to the softer side). E1-Standard Standardised interface for data and audio, frequently used for → multiplexers or → media converters.

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glossary of terms Electret Microphone Microphone using a semiconductor as sound converter (capacitive process). This technology makes very tiny microphones possible. Emergency-Call → Call-request with high priority (will be prioritised ahead of other calls), typically coming from a Help Point. ENUM ENUM refers to a set of standards and protocols which are used to translate the international dialplan (E.164) between a VoIP network and the → PSTN network. ENUM heavily relies on → DNS. Firewall A firewall is a dedicated appliance, or software running on another computer, which inspects network traffic passing through it, and denies or permits passage based on a set of rules. H.323 H.323 is a VoIP protocol used mainly by → PSTN - providers for audio communication around the globe. HDSL High Data Rate Digital Subscriber Line: a powerful and cost effective means of transmitting digital data over copper wires. IAX The open Inter-Asterisk eXchange protocol (IAX) is used primarily by Asterisk® → VoIP Servers to communicate with each other. Intercom over IP (IoIP®) Intercom over IP is a real-time protocol using IP-networks for networking Intercom Servers and connecting Intercom Terminals. It features much better speech transmission than VoIP thanks to a higher audio bandwidth of 16 kHz. Intercom Central → Intercom-Server Intercom Server The heart of an Intercom system: switches conversations between subscribers and transmits data to and from auxiliary systems with the help of interface cards. Built in a modular way, so for the functionalities required subscriber cards and interface cards are used. The functionalities of the whole Intercom system are programmed individually. Intercom Station The operator terminals of an Intercom system. Displays show the conversation partner, alarms or status information of integrated auxiliary systems, the keypad allows to dial-up a conversation partner or to control auxiliary systems. Intercom Terminals → Intercom Stations

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glossary of terms Interface Link to other systems (both to other Intercom servers as well as from Intercom servers to auxiliary systems). IoIP®– Intercom over IP Intercom over IP: use of IP-networks for networking Intercom servers. Compared to VoIP (Voice over IP), a standard for telephones, the advantage of much better speech transmission as using a higher bandwidth of 7 kHz stands out. IP Internet Protocol: asynchronous protocol for the packet transmission of information through a common network, e.g. the Internet (www – world wide web). IP-Rating Protection of a housing according to EN 60529: two figures indicate the protection against the intrusion of particles (mainly dust) and water. E.g. IP 54 is a usual requirement for door stations, IP 65 is a standard for heavy industrial stations. ISDN Integrated Services Digital Network: Internationally standardised system for digital telephones which defines both transmission and signalling. LAN Local Area Network: network limited to a small and closed environment, typically within a building, e.g. a company network. Usually a LAN is designed as an IP-network. Master Station Intercom station from which other subscribers can be dialled freely. Master stations have a full keypad. Media Converter Device that converts signals between two transmission means using different technologies, e.g. from E1 standard to fibre optic. Multiplexer Device that switches several inputs to one output, the data from several inputs are interlocked using various methods. NAT Network Address Translation (NAT) is a widely used technique used in routers which translates between an internal network (LAN) and an external network (WAN). A router using NAT is usually open for outgoing traffic but a barrier for incoming traffic. Networking Connection of Intercom servers and / or Intercom systems where the whole Intercom system behaves as one single system, i.e. all functionalities are available throughout the whole system. Programming and maintenance of the whole system can take place from one location and one Intercom server. Technologies used include: copper wires, fibre optic, S0 (ISDN) lines or IP-networks.

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glossary of terms Noise-cancelling Microphone Microphone built in a special manner so that sounds from a greater distance (e.g. background noise) are cancelled and sounds from shorter distances are transmitted much clearer. Ideal for noisy environments. OpenDuplex® Technological Intercom innovation by Commend. Due to this special technology both sides of a communication can talk at high volume and listen simultaneously, hands-free in crystal-clear speech quality. Thus Intercom systems by Commend offer perfect natural communication without the feeling of being limited by a technical device. Communication becomes independent of acoustic condition, like loud or sudden background noise. Package Transmission Asynchronous method for the transmission of data, mainly in networks. Data streams are divided into packages, which are re-assembled in the correct order at the receiving end. Varying delays in the network must be respected. PSTN The Public Switched Telephone Network (PSTN) consists of all of the world’s public telephone networks including landline and mobile phone networks. QUALITY OF SERVICE (QoS) Procedure in IP networks that prioritises certain connections and / or data packets by granting a defined delay and bandwidth. QoS is also used for the priorisation of audio data in shared IP networks. RTP The Real-time Transport Protocol (RTP) is used in → SIP phones and describes how digitalised and → encoded audio data is transmitted over the internet. S0 Network access interface for → ISDN SCCP The Skinny Client Control Protocol (SCCP) is a proprietary protocol used by Cisco Systems for their telephony solutions. SDP The Session Description Protocol (SDP) is used in → SIP phones for the initialization or termination of phone calls. SIP Session Initiation Protocol: network protocol for setup and handle communication session between two or more participants. The protocol is specified in RFC 3261. SIP is a frequently used protocol in IP telephony. Simplex → Conversation possible only in one direction and where the speech direction must be switched manually, e.g. by pressing the T-button (PTT – press to talk).

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glossary of terms SMD Surface Mounted Devices: very small electronic components mounted on the surface, makes high integration of electronic circuits possible. Soft Client A Soft Client is a program, running on a personal computer which replaces a common telephone by using software and a headset. Speech Channel Speech path, corresponding to one conversation, in an Intercom system. In analogue Intercom systems the number of speech channels simultaneously available is often limited. Star-Cabling Typical cabling for Intercom systems: all Intercom stations are cabled directly to the Intercom server in a star-like topology. Offers high operational security as the failure of one Intercom station or one line does not affect the rest of the system. Subscriber Interface of the Intercom server where a Intercom station is connected. Sub-Station Intercom stations which can only call predefined subscribers on an Intercom system, often only as call-request. Sub stations usually have only a single call button or a restricted keypad. Synchonous Data Transmission All procedures where data streams are transmitted continuously without interruptions. TCP/IP Transmission Control Protocol: protocol for secure data transmission using IP, e.g. for downloads from the Internet or for e-mails. Handshake for acknowledgement of data packets and automatic limiting to the available transmission rate. UDP Universal Datagram Protocol: protocol for data transmission without handshake, e.g. used for speech transmission or streaming in networks. VoIP – Voice over IP VoIP is the overall term for telephony solutions via IP networks. VoIP Server A VoIP Server is a dedicated computer which acts as a private branch exchange providing connections between VoIP and ordinary telephones, the → PSTN and other VoIP servers, networks and Asterisk®. VPN A Virtual Private Network (VPN) is a secured, private link though another network. It is commonly used to connect two remote locations over the Internet. WAN Wide Area Network: network limited to a defined environment, which can include several locations of a company, e.g. several LANs form a WAN. Commend International GmbH · Saalachstrasse 51 · A - 5020 Salzburg · Tel. + 4 3 - 6 62- 85 62 25 · Fax + 4 3 - 6 62 85 62 26 · office @ commend.com Version 1.0/0109 | Errors and omissions excepted | Products may change in the interest of technical improvements without notice.

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