PA Paging over IP Networks

You may have heard about Voice over IP or VoIP, well now it’s paging over IP. This is a new way to page or provide an intercom over the network. But how does this all work? How does your voice get on the network? Good question.

TCP/IP network technology makes local area networks and the Internet possible. It provides the basic communication protocol that allows all the information to move between all the computers on your local area network and over the World Wide Web. Now this same technology has been used to send voice, paging and intercom messages. Here’s how it’s done.

The way it works
First let’s understand some of the basics. Your voice is sound waves that are converted to electronic analog signals by a microphone. When you talk into a microphone that’s connected to your computer it’s converted to a digital signal. This is called analog to digital conversion. If you are using Voice over IP, then you may have a phone converter that does the same thing as your computer. It converts the analog signals to digital form and connects it to the network.

It’s interesting to note that the information on the network (or even over the Internet) is not sent all at once. You can start talking, and instead of sending this continuous stream of information, the information is broken up into batches or packets. It turns out that everything you do on the Internet involves packets. For example, every Web page that you receive comes as a series of packets, and every e-mail you send leaves as a series of packets. Networks that ship data around in small packets are called packet switched networks.

On the Internet, the network breaks an e-mail message and the voice message into parts of a certain size in bytes. These are the packets. Each packet carries the information that will help it get to its destination -- the sender's IP address, the intended receiver's IP address, something that tells the network how many packets this e-mail message has been broken into and the number of this particular packet. The packets carry the data in the protocols that the Internet uses: Transmission Control Protocol/Internet Protocol (TCP/IP). Each packet contains part of the body of your message. A typical packet contains perhaps 1,000 or 1,500 bytes.

OK, so now the information can get sent to another computer. Now how does this relate to a paging system? The paging system uses a special purpose computer (sometimes called an appliance because it’s very simple), to receive voice messages. Its job is to connect to the network, pick up the packets addressed to it and convert it back into analog form so it can be amplified and heard on a speaker. So the simplest paging system is a small computer with digital to analog converter, with audio amplifier and speakers connected to it. Now I can talk in one part of the building and be heard in another part of the building, or even across the world, over the Internet. Take a look at the block diagram below which shows the components inside the network attached IP amplifier.

An Intercom system is almost as simple. Now we use the same small computer (appliance) again, but add a microphone and analog to digital converter. Now I have the ability to talk both ways. It’s almost the same as using a VoIP telephone.

Components required to page and use an intercom over IP
At the school I used to go to this horrible sound would come out of a speaker on the wall. It was really almost impossible to understand. The page originated from the school office where the secretary or principal made all the announcements. This type of paging system required a central amplifier and wires that ran to each speaker. Paging and Intercom technology, just like many other products, have been transformed by TCP/IP network technology.

Using the IP network the world has changed. Now the messages travel across the network in digital form. Digital Acoustics provides a very flexible system that uses a standard PC to control paging and intercom activity. Take a look at the diagram below.



This system uses a standard computer with a sound card and microphone instead of a central amplifier. The special software allows you to send the voice data over the network to all the amplifiers and speakers attached to the network. The software allows you to select where you send your voice. It can be to just one of the speakers, any set of speakers or to all the speakers on the network.

The great thing about this type of system is that you don’t need a central location for this to work, when you use Enterprise software, you can page from any computer that runs the software. You can have multiple locations for paging and intercom control.

Paging Amplifier
The core hardware component to a paging solution is an Audio Amplifier module that connects to the network. For example the ii3-ESS can drive a single 8-Ohm speaker or multiple speakers in an array.

With the addition of a universal 25/70V transformer, a series of speakers can be powered by a single ii3-ESS, with the quantity of speakers determined by required output levels. With a maximum output of 20 watts (8 Ohms), the ii3-ESS is capable of driving paging horns with sound pressure levels in excess of 120 db SPL. For low output applications (<8>8 watts) an external power supply is required.

Every acoustic environment is unique and using the right speakers is important in providing intelligible public address solutions. There are a wide range of speakers available from companies such as Quam-Nichols. For example:

• 8" Ceiling Mounts - Round and Square
• Surface Mounted Enclosures - Square and Sloped
• Internal Horns
• External Paging Horns
• Corrections Grade Solutions (Vandal Proof)
• Weather Proof & Flame-retardant

You can also use standard PA systems to amplify and provide high quality sound to large meeting areas.

Intercom Units
The ii3-EDW, ii3-ESW intercom units are examples of intercoms that attach to the network. They used on a desktop or attached to a wall. Features include:

• High quality integrated speaker and microphone
• Four button controls include Volume Up/Down, Monitor/Open, and Push-to-Talk
• Four LED indicators include Active, Link, Monitor and Talk

Software
The software controls everything and allows you to talk to all the attached locations on the network. For example, the following software from Digital Acoustics makes it very easy to page and provide the intercom.

The software allows you to manage ii3 Intercoms from any PC. It also allows you to easily configure intercoms, control communications and archive audio files. TalkMaster-LE software is included with the purchase of any ii3 IP Intercom and makes for a total monitoring solution.

• Selective or master call to page all stations
• Master control and auto detection (integrated UDP polling)
• Provides remote door release and GPIO control
• Allows you to record, log and archive audio sessions
• Audio file playback (.WAV)
• Remote and local digital volume control
• Supports primary and secondary consoles
• iTalk/X Active X Software Development Kit (SDK) for custom integration

For sophisticated users and applications, there’s a more advanced software product called TalkMaster Enterprise Edition. This allows you to set up multiple control points for paging and intercom activity and in general provides flexibility in addressing the special needs of complex, multi-station, multi-operator and multi-site installations.

If you need some help designing your system, don’t hesitate to contact us. We can be reached at 914-944-3425 or 800-431-1658 or just use our contact form to get information.

Using an IP Cameras with Audio

An IP camera with IP software can be used to view and record video along with audio, but it may not be good for every application. IP cameras and software systems are designed for surveillance applications, so when used in a different application such as recording a presentation, may not be as good as using a standard camcorder. For example the audio and video may not be exactly synchronized. Slight differences can be seen on a web browser or when using IP video software (to record audio and video). There are also certain laws that relate to recording audio, and in most cases require people to be notified they are being recorded. With that said here are some things you can do.

Cameras with Audio
In almost all cases a camera that includes audio, supports MPEG4 compression. This form of compression includes data packets for audio transfer as well as video. For example, the Axis 210A includes two-way audio. It has audio input and audio output so you can attach a microphone and powered speaker. Other cameras with audio include Axis214PTZ and Axis211A, Vivotek IP6112, Panasonic WV-NS202 and WV-NP244.

Here is an example of a camera that can be used:

Axis210AL2
The AXIS 210A, indoor only camera with Computar 2.8-12mm manual focus, manual iris lens, delivers Motion JPEG images at up to 30 frames per second in all resolutions up to 640x480. With a built-in microphone and the ability to connect to external speaker or microphone, the AXIS 210A enables remote users to not only view, but also listen in on an area and communicate orders or requests to visitors or intruders. Includes built-in motion detection, and provides both full frame rate Motion JPEG and MPEG-4 video streams simultaneously. MPEG-4 compression mode is ideal for applications where available bandwidth is restricted and higher frame rates are required. Built-in Power over Ethernet allows the camera to receive both data and power over a single Ethernet cable.
The price is $570

Microphones
Just like any application using audio, you have to consider how to pick up the sound. If you just use the microphone on the camera (some cameras have this included) you will pick up all the audio in the room, including noise you don’t want. If you want to listen to a person talking, the microphone should be as close as possible to the person. You can use many different kinds of microphones including handheld, wireless microphones and even directional room microphones. Just make sure the type of microphone matches input requirements of the camera. Many of the cameras take “line level” type mics. These are similar to those used with audio components such as CD and DVD players, TVs, audio amplifiers and other consumer equipment. Cameras usually accept the 3.5mm mono audio input. In some cases the microphone doesn’t have the right connector for the camera, but this can be corrected by using an adapter.

Wireless Microphone
The following wireless microphone can be used with IP cameras that have an audio input. The person can wear the lapel microphone or hold the microphone. The receiver connects to the audio input of the camera.

WMS-Pro
Azden Pro wireless VHF Mic system. Excellent sound quality at a range of over 250 feet. 2 switchable frequencies (169.445 and 170.245) to select the clearest sound. Receiver comes with belt clip, velcor and shoe mount. Includes one clip-on mic and one hand-held mic, either of which plugs into the mini transmitter. Clip-on mic transmitter attaches to belt or fits into pocket. Supplied with Leatherette carrying pouch and monitor ear phone. Both receiver and transmitter operate on 9V battery (not included)
The price is $235

Room Microphone
If instead you need to use a room mic, the Louroe omni-directional microphone can be used. This uses a very sensitive electret condenser omni-directional microphone with a pre-amp so it can be used with the camera. This is a good camera for small rooms. The police like this for interrogation rooms. Note that this also picks up all the noise in the room so it's not good if there are a lot of people talking.

The following kit includes everything you need to pick up sound in a room.

ASK-4 Kit300
Single zone audio monitoring system designed for direct connection to a camera. Omni-directional microphone can pick up normal sounds 15’ away or within a 30’ diameter circle. Provides three different audio outputs: RCA audio output to a DVR or VCR with RCA type audio input 3.5mm mono audio output to a DVR with 3.5mm mono audio input, 3.5mm stereo audio output to a camera or computer soundcard, or DVR with a stereo audio input. A connector cable for each type is included with. ASK-4 #300. Distance between the Verifact A. Microphone and Model IF-1 Interface Adapter may be up to 1,000 ft. using recommended wiring.
The price is $205

There are many other microphones that can be used. Contact me for some more recommendations.

How to hear the sound at a PC

A PC with a sound card allows you to view the video and hear the audio. Storing the audio and video requires special software and broadcasting to many people requires different software.

Viewing and hearing the audio
The simplest way to view an IP camera and listen to the audio is to use a web browser. Internet Explorer accepts the ActiveX component provided by the camera that allows you to see and hear the camera. Unfortunately many of the other browsers don't support the Active X. Also only a few people (up to 10) can view the video at the same time.

Storing the Audio with the Video
To store the video you need special IP software. OnSSI has a number of products that record audio as well as the video. ProSightSMB allows you to record the audio from only one camera. NetDVR allows you to record audio from all the cameras that have audio, but you can only hear the audio played back at the server and not hear it using the NetGuard Client software at other PCs on the network. NetDVMS records all the cameras and allows you to hear the audio at both the server and at various PCs on the network that are running NetGuard-EVS client software.

Here’s an example of the software that can be used:

NetDVR-04C
4 Camera license - NetDVR provides access, viewing and control of surveillance cameras from any location on the network. Totally software based system which can be installed on a standard PC workstation. Instant Search on time date or activity alarm. Supports up to 30fps per camera. Secure time stamped and watermarked recordings. Fully adjustable Video Motion Detection. Can be expanded by trading in the software for the next level of license.
The price is $1195

Speakers

You can talk through an IP camera that has audio output. Some cameras have built-in speakers, but in most cases you need an external powered speaker. The speaker needs to be powered because the camera doesn’t have enough amplification power. The cameras that support two-way audio have a 3.5mm mono audio output similar to the microphone input connection. I have seen some cameras with only one shared audio connection so be careful about this. In this case you need to use a splitter that allows both a microphone and speaker to be connected.

Almost any type of powered amplification system, like a PA system, can be connected. There are also some special powered speakers available that can be connected directly to the cameras. Here’s one example:

IPX-SA
Speaker assembly for the cameras. The IPX-SA which is a 5” square, weather-resistant, black, metal, speaker box (2” depth) with a built-in amplifier. This unit can be wall-mounted outdoors but it is not designed to withstand direct moisture or harsh environments. The amp takes a 12VDC input which can be pulled from the 12VDC terminal inside the IPX-ED-24V enclosure
The price is $135

How to speak through the camera

At the moment, you can only speak through a PC (with sound card and microphone) using Internet Explorer. There is a microphone button that can be pushed to allow you to send audio through the camera to the speaker. Software companies are working on support for out bound audio.

Webcasting

Surveillance type software is not made to broadcast or web-cast to many people on the network. You need other software to create a web server that allows many people to connect to a real-time or stored video presentation that includes audio. There is no simple solution that we know of. It will require some programming or system work to get this done. One simple approach to create a web cast is to export the audio and video to an AVI type file. This can then be cached in a computer and used in a web server that allows many people to see it. NetDVR or NetDVMS software can provide this export data from the stored video and audio files.

If you need more information please contact me. I can be reached at 914-944-3425 or by contact form.

Archiving Appliances and Systems

How to comply with the archiving regulations without paying an arm and a leg
Archiving Appliances make it easy to protect your data

So you are being dragged kicking and screaming to archive your e-mails and data. What can you do that doesn't cost an arm and a leg? Well, there are some new economical systems available that make it easy to get the job done. They are called Archiving Appliances and they take advantage of the same robotic mechanisms used in automatic duplicators. With these systems you can archive e-mail data or general data to a stack of DVD optical discs.

This is a batch process where a set of blank discs are placed on a spindle and written one-at-a-time and placed on an output spindle. Then you can store the discs off-line in a drawer or cabinet until you need to read them. You can read the discs using the same appliance by placing the discs on the spindle. If you need faster access to the data, you can use a jukebox or library system instead of the archiving appliances. The jukebox or library is more complex and provides not only archiving (writing), but also easy on-line accessing (or reading) of the discs.

The Difference between Backing up and archiving
Most people can’t recover emails from even a year or two ago. Why? Because even if system backups are performed regularly, the emails are often deleted from servers during routine tape rotations. Tape can also break, wear out and become demagnetized. But what happens when some of those emails or files are needed in a lawsuit? Or what if a regulatory agency asks for specific emails and you can’t produce them? The liabilities to an organization can be substantial.

Tape backups are relatively short term storage of data. It protects your data from inadvertent erasures, system crashes that destroy the data or catastrophes that damage your data center. Tape is usually used because it’s fast and relatively automatic. But, it is not archival media. Archiving means you will copy data to media that will last for over 20 years. Optical discs are the only media that is rated for this long term storage. Experts agree that optical media is the most rugged and reliable backup media available. Its archival life is measured in decades — not just years.

WORM (Write Once Read Many) is Non-erasable, non-rewritable optical media that can be stored off-site. This is a critical specification for publicly-held corporations, healthcare, brokerage and financial institutions and others who must meet the strict email, data and document retention requirements of Sarbanes-Oxley, SEC 17-a, HIPAA and a host of other government regulations.

WORM technology is also highly desirable for any organization that needs to be able to quickly and reliably retrieve data and files of all types without overburdening primary storage devices or media. In this case, Jukeboxes or libraries are used. Not only can they be used to archive your data, they can also be used to easily retrieve the stored data.

Archiving Appliances
There are number of different systems available that provide automatic data archiving. For example, the ArcEmail Archiving Appliance makes it easy to archive Microsoft Data Exchange E-mails. The ArcBackup appliance archives your general computer data to optical discs, and the ArcPoint archiving system adds more sophisticated rules for transferring data to optical discs.
Here’s a summary of the systems available:

E-mail Archiving
The ArcEmail Archiving Appliance backs up and quickly recovers all e-mails that are sent, received or deleted through Microsoft Exchange, including attachments. It operates unobtrusively in the background of your Exchange server, reliably backing up all emails on optical media. The discs can be kept save and then recovered easily when needed.

The system writes to DVD discs and then prints a label on the disc so you can find it. When you need to recover emails from any mailbox for any date range the system finds them on the appropriate backup discs and restores them automatically.

The system provides the following functions:

• Provides an E-mail Archive Appliance for Microsoft Exchange
• Automatically archives to DVD optical media
• Uses Write Once Read Mostly (WORM) media that prevents overwriting and lost data
• Has a 25 Disc capacity
• Allows you to Archive over 100GB per set of discs
• Automatically labels discs
• Provides easy retrieval
• Connects to your PC through USB 2.0 port
• Includes EMC® Retrospect® for Windows

Data Archiving Appliance
The ArcBackup archiving appliance is a simple device that transfers data to a set of DVD discs. The data set is very much like a tape backup except the data is written to optical media. The discs are labeled so they can be stored off-line and retrieved when necessary. The set of data on the discs can be recovered by placing them back on the input spindles and running the recovery software. With this system you can:

• Schedule backups
• Creates a backup set of discs
• Compresses files
• Easily restore the data
• Supports disc spanning: Large backups will be automatically split to several parts and stored on several disks
• Print labels
• Supports encryption for added security

There are currently two models to choose from. The 25 disc and the 300 disc units provide a range of capability.

Hierarchical Data Archiving Appliance
The ArcPoint appliance is a more sophisticated version of the ArcBackup appliance. It uses the same type of duplication mechanism, but the PoINT Archiver software provides much more functionality.

ArcPoint includes a Windows Server application providing a secure and cost effective process to identify, monitor and archive relevant data in a network. It provides a central “console” from which you can manage the archival of data throughout the network. Archiver periodically monitors network folders and copies or moves files to removable optical media according to Administrator defined filters. Additionally, criteria can be defined to identify and archive multiple versions of the same named file.
Point Archiver provides the security and authenticity of information which is required to fulfill the constantly rising number of compliance regulations. Archive jobs monitor existing data folders and files. An intuitive Wizard interface provides step by step procedures which allow the administrator to specify:
* Name for the Archive
* Media type and Target Device
* Data source folders, files & extensions
* Archiving conditions
* Migration Rules

Data and E-Mail Archiving Appliances

Here’s a completely new technology we just started to work with. It solves one of the major problems in trying to conform to the new regulations about data storage.

So you are being dragged kicking and screaming to archive your e-mails and data. What can you do that doesn't cost an arm and a leg? Well, there are some new systems available that make it real easy to get the job done as well as being economical. The Archiving Appliances take advantage of the same robotic mechanisms used in automatic duplicators. With these systems you can archive e-mail data or general data to a stack of discs. This is a batch process where a set of blank discs are placed on a spindle and written one-at-a-time and placed on an output spindle. The discs are stored off-line and can be accessed by reading them back in using the same mechanism. The jukebox or Library systems are more complex and are the only devices that provide easy on-line retrieval of the discs.

The Difference between Backing up and archiving

Most people can’t recover emails from even a year or two ago. Why? Because even if system backups are being performed, emails are often deleted from servers during routine tape rotations. Tape can also break, wear out and become demagnetized. But what happens when some of those emails or files are needed in a lawsuit? Or what if a regulatory agency asks for specific emails and you can’t produce them? The liabilities to an organization can be substantial.

Tape backups are relatively short term storage of data. It protects your data from inadvertent erasures, system crashes that destroy the data or catastrophes that damage your data center. Tape is usually used because it’s fast and relatively automatic. It is not archive media. Archiving means you will copy data to archival media that will last for over 20 years. Optical discs are the only media that is rated for this long term storage.

WORM (Write Once Read Many) is Non-erasable, non-rewritable optical media that can be stored off-site. This is a critical specification for publicly-held corporations, healthcare, brokerage and financial institutions and others who must meet the strict email, data and document retention requirements of Sarbanes-Oxley, SEC 17-a, HIPAA and a host of other government regulations.

WORM technology is also highly desirable for any organization that needs to be able to quickly and reliably retrieve data and files of all types without overburdening primary storage devices or media. Jukeboxes or libraries are used for easy retrieval. Experts agree that optical media is the most rugged and reliable backup media available. Its archival life is measured in decades — not just years.

I will post some more details in a few days. If you need some more information check our web site. or just contact us using our form

Power over Ethernet for IP Cameras

You would think it was simple, but it's not. There's more to Power over Ethernet (or PoE) then meets the eye. Just so we are all on the same page, PoE is a way of providing power to a device on the network. For example an IP camera that connects to the network can be powered over the same cable that is used to provide network data. The power is provided using extra unused wires in the network cable. If a camera conforms to the IEEE 802.3af standard, PoE is easy, but if it doesn't things can get complicated. Many cameras whether they conform to the PoE standard or not can be powered over Ethernet.
Here's how to do it.

Power Requirements depend on the camera

In all cases, power (that's voltage and current) is sent over the extra network wires. The wires are not very heavy (gauge) so they limit the power available at the device. The way the power gets to the wire and the way it gets to the camera can vary. Not all cameras use the same voltage. Some use 5VDC, other 12VDC or even 24VAC. As I mentioned, there is also an IEEE 802.3af standard that defines the PoE voltage and current. Many new cameras conform to this standard, while many older cameras have an external connector where power can be plugged in. Cameras that are compatible with IEEE 802.3 can get their power through the RJ45 network connection.

The power required by the camera system determines if PoE can be used

Most IP cameras can use PoE, but there are some cameras that require too much current and can't be powered over Ethernet. PTZ cameras require the most current because their little motors use a lot of power. For example, the Axis 214PTZ and Axis213PTZ can be powered. Since they require more current they require a higher powered midspan. On the other hand the Axis 231D and Axis232D+ can not be powered with PoE because they exceed the current that can be carried over the Ethernet wires.

PoE is great for indoor applications. It allows you to use a single cable to connect the camera, which greatly simplifies the installation. When the camera is used outdoors in an environmental enclosure and a heater and blower is required, you can't use PoE to power the enclosure because it requires too much power. Installation is still fairly simple because you can use the same power that goes to the heater and blower to power the camera.

If you plan to use a wireless camera, obviously you can't use PoE. I mention this only because we have actually been asked this question.

Power over Ethernet Solutions

Here are some details on how power is provided over Ethernet. Power is inserted to the network wire going to the camera using a powered network switch or a midspan (or power injector).

The power is connected to the camera either through the RJ45 network cable connection or using a special splitter that provides power to an external power connector on the camera.

Here are the solutions available:

Solution 1A: When you have an IEEE 802.3af compliant network camera you can use a PoE-enabled switch to provide the power. The camera uses the standard 48VDC power and uses the power from the RJ45 cable connection.

Solution 1B: If you have a IEEE 802.3af compliant network camera but do not have a powered network switch, you can add a midspan or power injector that complies with the standard. It's placed between the standard switch and the camera. Again the camera doesn't require any splitter because it uses the standard 48VDC power from the network connector.

If the camera is not compatible with IEEE802.3af standard, you will require a splitter at the camera side. An active splitter can be used to convert the voltage from the voltage injected (could be 12VDC or 24VAC or 48VDC) to the right voltage for the camera. If you have a powered switch that conforms to the standard, the splitter will convert the voltage from 48VDC to 12VDC or 5VDC (depending on the splitter). You need to select the right splitter for the camera so that you get the right amount of voltage and current as well as the right connector.

There are two solutions available:

Solution 2A: When you have a Network camera that does not conform to the IEEE802.3af PoE standard and you have a PoE-enabled switch, you will need to add an active splitter that supports the standard power. The splitter has to be matched to the camera.

Solution 2B: When you have a Network camera that does not conform to the IEEE802.3af PoE standard, and have a standard (non-powered) network switch, you will require a midspan or power injector and an active splitter. In this configuration the midspan or injector could provide IEEE standard power or non-standard power (24VAC for example). As long as the splitter is compatible with the midspan and camera, it will work.

If you still have questions about PoE or need help selecting the right camera system, just go to my web site or contact me.

Power over Ethernet

The other day I was asked about powering an IP camera over Ethernet. It turns out to be a bit confusing so I thought it would be helpful to write this down and un-confuse it.

First of all there are many different types of IP cameras. Some of the new cameras conform to the IEEE standard, but many of the older cameras have unique voltage and current requirements.

In some cases the camera manufacturer will recommend and even provide a Power over Ethernet (PoE) solution. For example Axis and Sony make it easy because they have a solution for many of their cameras. When the camera manufacturer doesn't suggest anything, you have to do some investigation.

I'm still working on the details and will get back with more information after the weekend.

How to Select the Light Sensitivity of the IP Camera

It is important to know the complete light range that is required for your cameras. You may have some cameras that will be used in dark areas and some others that will be in well lit areas. If necessary, you can select a different camera for each location. Not only do you need to know how dark it gets, you also want to know if you will have a problem with sunlight shining into the lens in the morning or evening. This can affect where you will place the camera. The minimum light sensitivity is important if you plan to use the cameras at night.

1. Go to all the camera locations during the night and see what type of lighting is available (if any).
   
2. During the day make sure the camera is not pointing into the rising or setting sun.
3. At night determine how much light is available at the location.
   

Lux is the measure of brightness. To get some idea of the lux value, consider that 1 lux is about the light from a full moon. If the light is less than this, you will require a more sensitive camera (costs more). If the light is more than this you can save money. Take a look at the Kintronics web site for more information about the cameras available.