What is a Repeater?
A repeater is simply a device that receives incoming signal and retransmits the signal either adding power or around an obstruction. Unlike a mobile phone tower, a repeater does not interpret the signal in any way and hence any incoming signal on the repeaters frequency will also be retransmitted (eg. noise).
Passive vs. Active Repeaters
A quick overview of the two types of repeaters.
An active repeater, commonly called a cell phone 'booster', is any repeater that adds power to the incoming and outgoing signal. This type of device is designed for households and vehicles that can only receive a weak signal. An active repeater is simply a digital signal amplifier (much akin to the amplifier you would find in your home theater system) and even smaller models can add around 20-50dB to the signal.
You're probably thinking this is the perfect product for your needs, however active repeaters are strictly banned in Australia and those who continue to use the technology can be fined up to $220,000. This is due to non-compliant mobile phone repeaters (currently all models except for the Telstra Smart Repeater, and Optus Smart Repeater) interfering with the performance and accessibility of mobile phone towers by other users. A good analogy would be walking into a crowded room and using a pair of loud-hailers to talk to the person next to you - great, you can hear each other, but at the cost of everyone else.
If you've seen these for sale by other 'Australian' retailers, read our exposé here.
Here is an extract from the ACMA website:
"Using non-compliant boosters disrupts network operation and reduces performance. When a booster is used, increased power levels swamp nearby base stations to the point where they become 'blinded' to other calls. Coverage is reduced to a small percentage of the original area, and as more boosters are used, the coverage degradation worsens.
For a booster to operate correctly, it would have to respond to the network demands to reduce output power when approaching a base station. Non-compliant boosters do not reduce power and have caused severe interference, particularly in regional areas. In these areas, high call drop-out rates have been associated with the use of boosters.
Testing found little or no improvement in coverage or performance compared to the use of a correctly installed car kit with an external vehicle antenna.
Access to the network by other service users may be severely restricted and therefore calls to emergency services may be disrupted. For example, lives could be put at risk should people trying to call emergency services have access restricted because of boosters being used by other customers."
Optus/Telstra Smart Repeater
This is the only repeater legalised for use in Australia. The Smart Repeater system is very different to a standard repeater, as it was designed to provide maximum coverage while remaining network friendly.
It does this in several ways by:
- continuously monitoring power levels of the cell tower it is connected to and constantly adjusting its output power to suit.
- only amplifying and disbursing a particular carrier’s mobile signal, operating within a set frequency band.
- giving the service provider the ability to shut down the repeater remotely if needed, using a signal from the base station.
- not interfering with the carrier’s network or other users on the network.
- having a unique installation process to eliminate feedback into the mobile network.
The smart repeater is often considered an expensive option but remember that a smartphone often costs around $600-800 (usually factored in to your monthly bill). If your expensive new phone cannot reliably connect to the network, you're not getting the most out of your phone!
Installing the smart repeater unit is a simple matter of locating an area in the house where you receive strong phone signal and placing the primary unit there. The second unit (called the Coverage Unit) is then placed in the middle of your house where signal is worst.
You May Still Need an External Antenna
While the system can be used without an external antenna, this is rare. As the old saying goes; Garbage In, Garbage Out. If your repeater is picking up a poor quality signal, it is only going to rebroadcast that poor quality signal 'louder' - meaning you will still face call drop-outs and digital garbling. Using an external antenna, such as a roof mounted yagi, will allow the repeater to pick up a good quality signal that it can repeat indoors at full strength. This allows five mobile phones and modems to send and receive information at a very fast rate, resulting in fast 3G broadband and excellent voice call quality.
You can purchase a Smart Repeater for either the Optus or Telstra network here.
A passive repeater on the other hand is simply a device that receives and retransmits the incoming and outgoing signals without adding power or amplifying the signal whatsoever. This type of device is commonly installed when a building's structure or roof is stopping a mobile phone signal from penetrating, causing reception to be strong outside the building but very weak inside.
A passive repeater requires a very strong signal outside, and a high gain external antenna (usually a directional yagi or high gain collinear) mounted clear of the roof. This high gain external antenna is then connected to an internal low gain antenna inside the building by a cable running through the roof or wall.
How do I set up a Passive Repeater
In our experiences conventional ceiling-mounted passive repeater systems do not work effectively. While the theory and technology works perfectly, the inverse-square law of RF propagation results in almost all signal increase is lost after the first metre. We can however take advantage of this brilliant technology by instead of connecting a ceiling antenna, connecting up a large pad antenna that can sit on your desk and any phones placed on the pad are provided the increased signal.
Much like a regular passive repeater system, this type of setup requires the following items:
- High gain external antenna
- Low loss cable
- A large flat antenna for sitting phones on
- A Bluetooth compatible cordless phone, such as the Uniden XDECT 6135BT.
For the external antenna, a high gain directional antenna, such as a 16dBi Yagi Antenna will provide a very high gain and should provide plenty of signal when installed pointing in the direction of the nearest mobile phone tower. While providing best performance often this antenna (at a whopping 2.4m in length) is a handful to mount, so 14dBi Yagi's are a good compromise between performance and ease-of-installation.
This antenna should be used with a super low loss cable like LMR400, to ensure maximum signal is transferred to the internal radiating antenna. A 10m LMR400 cable will do the trick for most households and will incur a measly 1.2dB of loss over the whole 10m (when used with Telstra Next-G), compare this to standard RG58 cable, which will lose around 4.6dB over the same distance.
What you're looking for here is a nice flat antenna with a large surface for placing phones on. You can place as many phones as you can fit on the antenna (you can even stack them on top of each other!). We recommend a high quality panel antenna such as our Internal Flat Panel Desk Antenna, which when tested against a number of other panel antennas provided the most significant improvement in mobile phone signal.
If you don't feel like customising your kit we sell a high quality House-Wide Coverage Kit containing all antennas, fittings, cabling and brackets required for this set up.
With the Total House-Wide Coverage Kit you can make and receive calls from your mobile phone anywhere in the house. Simply leave up to four Bluetooth enabled phones on the pad and enjoy the freedom as your calls are then routed through a stylish cordless phone system.
By placing a strong antenna on the roof and running a cable inside we negate the blocking effect. The internal panel re-broadcasts the signal obtained by the roof antenna exceptionally well, but because of the 'inverse square law' of RF transmission signal improvement drops off rapidly as you move away from the panel. By placing your phones on the internal panel antenna you can enjoy improved phone reception without having to connect with a cable or specially designed cradle.
The Bluetooth cordless phone system can then be used to route calls from up to 4 mobile phones through the cordless handsets, meaning you can enjoy the freedom of movement throughout your home and still make phone calls. The cordless phones only need a spare power-point and can be used even if you already have an existing cordless phone system.
From experience we find most phones will pick up almost all of the signal obtained by the external antenna when placed next to the internal antenna, with signal decreasing as per the inverse-square law as the phone gets further away from the antenna. Usually even a small increase in signal will be enough to make the difference between making a call or receiving a text message.