Hardwired Vs Wireless Security Alarm Systems - How Secure is Your Security System?

By Roy Stephenson

wireless security alarmAge old questions abound which spark a constant series of debates. Which is better, Chevy or Ford, Coors or Budweiser, winter or summer?

Ask a couple of alarm guys which is better, hardwired or wireless and you are sure to receive some pretty strong opinions supporting one or the other. Battle Lines being drawn, let's try and get to the bottom of this sharply divided issue.

Hardwired alarm panels are less expensive than wireless panels, but they are harder to install. Keep this in mind if you are planning on doing the installation yourself. An average home installation with a hard-wired system takes about 12-16 hours. A typical wireless installation will take less than 4 hours.

Another consideration is that some types of construction lend themselves well to a hardwired installation, and others will require the use of wireless. Normally all commercial alarms are hardwired, and a large percentage of residential installations will utilize wireless.

Even if you purchase a wireless alarm panel, most installations will require that some of the devices are hardwired. These typically include the power transformer, the electrical ground wire, the telephone connections and any keypads/arming stations and audible alarms. There are some exceptions to this like some of the newer all-in-one units currently being offered which incorporate the base unit, arming station and audible alarm into a single unit that plugs into one of your existing phone jacks.

The main difference between a hardwired and a wireless alarm panel is how each one communicates with the protection devices connected to the system. A hardwired panel will require a wire to each "zone" or device on the system, while a wireless system utilizes a radio frequency to communicate with the "zones" or devices that are connected to it.

While a normal electrical circuit is a Parallel Circuit, a typical hard wired alarm circuit is a 2-wire normally closed loop with end of line supervision commonly referred to as a Series Circuit.

A Series Circuit allows electrical current to flow from the alarm panel, down one wire through the alarm initiating device and back to the alarm panel. When the current is interrupted, the panel will register a fault on the circuit/zone. End of Line (EOL) resistors are added to the circuit so that the alarm panel can supervise the condition of the zone for ground faults, electrical shorts and open or cut wires.

Multiple normally closed devices can be connected to a single zone by connecting the devices in series, with the EOL resistors installed on the last device in line. This way, the entire circuit is completely supervised from the panel to the last device in line.

When wireless alarm systems first appeared on the market, they were not the most reliable systems around. Most of them utilized non-supervised wireless transmitters to communicate to each of the field devices. A non-supervised wireless alarm transmitter would only send a signal "one way" to the alarm panel receiver when it was activated.


wireless alarm systemFor example, when a door or window was opened, the transmitter would send a wireless signal. The alarm panel would receive the signal and activate the appropriate zone. The transmitter would not send a signal when the door or window was closed, so the receiver/zone had to reset itself after a few seconds. With a non-supervised wireless system, you could actually arm the system with a door or window wide open without even knowing it.

Most new alarm systems utilize a redundant bi-directional fully supervised wireless connection for two way communication between the transmitters and the alarm panel receiver. With fully supervised wireless, the alarm panel can tell you the real time status of a door or window. If a door is open, it will keep the zone faulted until the door is closed.

Most of the early wireless systems were very limited in their addressing schemes. They utilized dip switches with binary addressing (explained later) to differentiate between points on the system.

This was O.K. if your wireless system was installed and commissioned correctly, but what happened when your neighbor installed the same type of system? If the neighbors motion detector was addressed the same as your garage door, your alarm would go off every time they moved around their house. As you can imagine, this could cause some major problems that were very difficult to troubleshoot.

Modern wireless systems utilize serial numbers, binary house codes, or other proprietary technology to assure that only transmitters enrolled into your panel will be received by your alarm system. If you do your research and purchase a good reliable supervised alarm system, you should never need to worry about your neighbor's wireless transmitter setting off your alarm system.

Another problem with the older non-supervised systems is that you did not know when the batteries in the transmitters are low or need to be replaced. The only way to verify that they were working is to periodically test them.

Because, even the most sophisticated wireless alarm panels are useless if the transmitter batteries are dead, therefore supervised wireless panels are programmed to check in with each of the remote transmitters at least once every 24 hours. If your transmitter has a low battery, the keypad/arming station will immediately inform you of the trouble condition.

With any wireless security system you should always test the performance of your system regularly. The range of any wireless product can be affected by the environment and the structure in which it is installed. Additionally, the range can be adversely affected by environmental conditions, interference form electrical devices or even the orientation of the transmitter in relation to the receiver.

So who is the winner of this argument? Well, according to Underwriters Laboratory (U.L.), the most secure and reliable installation methods utilize hardwired installations with End of Line (EOL) 1 or 2-resistor supervision. In fact, U.L. approved installation standards for federal government and other high security installations require all zones of protection to be hardwired with complete 2-resistor line supervision.

Not to say that wireless systems are an inferior product. In fact the fully supervised systems offer excellent protection that is perfectly suitable for 90% of residential installations.

If you are considering a wireless alarm system, be warned, there are still systems being sold and installed today that are non-supervised, so make sure that any system you are considering offers complete wireless supervision.

If you opt for a hard-wired alarm system, make absolutely sure that the system is installed with the supervisory resistors at the end of the line. To make installation faster and simpler, some installers will place the resistors in the alarm panel rather than at the end of the line.

While this method provides supervision of the zone for ground faults, it does not provide protection for a direct short or worse yet, someone splicing into the wire and shorting them together which will essentially close the loop so the panel will not see the zone open or close.

Wireless Home Networking - Choosing The Right One

By Lynn Chan

Wireless Home NetworkingAre you suffering from home wireless networking nightmare? There are so many options. 802.11a, 802.11b, 802.11g - what is all that? All you want is to get online on your notebook computer in your living room without tripping over wires.

First thing you should know is, all of them will get you online or network your computers together. The difference lies in speed, connection quality and more important today, security.

802.11a offers one of the fastest wireless home networking speeds because it runs on a much higher frequency that few other home electronics like phones and microwaves can interfere with. It can also accommodate more computers connected simultaneously - which is why more businesses use it since it's unlikely a typical wireless home networking setup requires so many connections. So this sounds like the perfect solution right?

Yes and no. The high frequency apparently is its worst feature as well. Many experts will tell you higher frequencies are easily absorbed and result in shorter ranges. It also means it's less able to overcome obstructions like walls.

That's not all. 802.11a and 802.11b are two separate frequencies so if you have a notebook computer capable of connecting to only 802.11a networks, it won't work in a 802.11b setup and vice versa. But, this is probably one of your least worries because many wireless connectivity hardware today are capable of connecting to either one.


Wireless Home Network802.11b uses a lower frequency. So that expands the connection range but that also means it shares the airspace with other electronics and will likely experience much more interference. On top of that, experts advise that 802.11b networks are weaker when it comes to encryption and security. Also, as you expand your range, you're also more prone to people trying to crack into your network from further away and more concealed places. That's certainly an interesting point.

Finally, but definitely not lastly (there are many more 802.11 variations than presented here), is 802.11g. This is somewhat of a hybrid of the two earlier standards. First it uses the same frequency as 802.11b so, you get the benefit of a wider range. Secondly it's capable of much faster speeds like 802.11a. The third plus is it's also compatible with 802.11b networks. So you don't have to get new hardware to make connections with an older network or newer network (depending what you have currently). And, since it's a newer standard, encryption is also better, and that means you can better secure your home network.

However, 802.11g wireless home networking hardware still costs more to set up than 802.11a but considering the many plusses it has going for it, this is at time of writing the best choice for your wireless home networking setup. Besides, there are plenty specials going on, prices are coming down rather rapidly for both routers and network cards.

Lynn Chan helps new owners learn proper notebook care and use. Start taking care of your investment, with this free course 5 Days To A Healthier Notebook Computer [http://www.notebook-computer-infocenter.com/5days-to-a-healthier-notebook.html]

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