Frequently Asked Questions

 

We can provide small to medium solutions using the Smart Repeater systems - from residential dwellings, basement car parks to medium sized offices.

For multi-story buildings and large shopping centres, these typically require distributed antenna systems (DAS) or leaky-feeder installations.

These are far more advanced systems that utilise a direct connection to a carrier's network, and can cost anywhere from $50,000 to $500,000 depending on the scale and complexity of the required system.

For more information about In Building Coverage or IBC for large buildings, please see the following MCF Fact Sheets.

 

Only if you're in a strong 4G area, which is usually less than 3-5km from a city centre or large town.

If you're outside this range, you will be using normal 3G, which only uses one antenna.

Even if you're in a 4G area, two antennas are not necessary as the second antenna is only used to increase speed and not signal strength.

 

No.

You can't make a phone call on 4G, so you just need a normal 3G antenna.

You only need a 4G antenna if you intend on using the high speed 4G data network and are located in a 4G area, (usually only a few kilometres from a city/town centre).

 

 

No.

This is a very common question, however TV antennas are designed to receive only TV signals.

Antennas are designed for a particular frequency range - with TV operating in the 700MHz band, and mobiles/broadband operating on either 850 or 900MHz, the two frequencies are too far apart for an antenna to function.

TV antennas also have a different input impedance - 75Ω compared to 50Ω required for telecommunications.

 

No.

This simply means your phone is capable of running on the Telstra 4G high speed data network, however, as this network is only used for Internet services in city areas, you don't need a new antenna if you're making calls, or are not in a city area.

If you want to take advantage of the high speed data network, you will need a 4G capable antenna.

 

Selecting a 4G antenna depends on a couple of things:

• your location, and

• whether you need a portable or permanent solution.

 

4G Antennas - around town

If you can receive Telstra 4G outside or just down the street, or just need to increase speed, generally nothing drastic is required.

Take a look at our convenient desk mounted 4G antenna for indoor use, or our compact Omnidirectional 4G MIMO Antenna for a high performance weatherproof roof mount antenna.

 

4G Antennas - outside official coverage zones

When connecting to 4G towers in the distance, you'll need a more substantial antenna.

If you're confident you can lock onto a 4G signal, our 4G grid antennas are used right around Australia - from mining and heavy industry, to commercial factories and residential houses.

If you need a 4G antenna that can fall back on 3G/Next-G, if 4G is not available or too weak, the best antenna is our 12dBi multiband 3G/4G Yagi

 

Currently most Samsung, Motorola, and Telstra ZTE model phones have RF ports located underneath the back cover of the phone (next to the battery).

Often the port can be covered with a thin piece of plastic, or rubber lug, which must be removed to reveal the patch lead connector.

To determine what lead you need, locate your phone in our patch lead menu.

Be sure to read through the information as it will help you correctly using the patch lead.

If your phone is not listed, please send us an email.

 

Ignoring terrain and other real world factors, the answer depends on how the cell tower is configured.

Many remotely located cell towers are configured with a search window of 160km.

A search window is the upper limit imposed by the cell tower to reject connections that have a propagation delay exceeding a predefined value.

Search windows are used to keep processing overheads low (and hence hardware costs low) on cells with a small footprint.

For smaller cells, such as those located in suburban or metro areas, the search window may take a value as small as 30km.

 

With the exception of a Cel-Fi Smart Repeater, no.

Amplifying a mobile phone or modem signal without carrier permission using AC power is illegal, and carries heavy penalties under the Radiotelecommunications Act 1992 (Cth).

This is because a repeater/booster is also a signal jammer - boosting your signal at the expense of everyone else in the area.

For Australian customers, we offer a legal Smart Repeater - view our selection of smart repeaters and smart repeater kits

This type of repeater communicates with the cell tower to adjust its output power so as to not disturb anyone else.

For more info and legal options see our guide to repeaters.

 

Because they don't exist.

To increase the gain of a Yagi antenna by 3dB you have to double its length.

Our Telstra 16dBi Yagi measures 2.4m in length, so you can imagine a 19dBi Yagi would measure between 4-5m in length, and a 21dBi Yagi about 9m!

If your Telstra or Optus Yagi claims to have a gain of over 16dBi and isn't over 2-3m, you should contact your supplier immediately.

A good quality 16dBi Yagi should measure at least 1.8m in boom length.

You can read our comprehensive Why we don't sell 21dBi Yagis guide for a more detailed explanation.

 

Follow our comprehensive Guide to Locating a Phone Tower

If you need to determine the best cell tower to connect to, we can perform a detailed tower analysis using computerised RF modelling.

 

You'll need to navigate to your phone's network status or engineering menu - see our Guide to accessing your phone's meter for instructions for some phones.

Once you've found the menu, you need to write down the Cell ID/LAC/CID code.

This is the unique identifier for the tower's antenna you are connecting to - note that many cell towers have three transmission antennas, each covering a 120 degree angle.

Next, locate your nearest cell towers by following our Guide to Locating a Phone Tower

Now that you know where they are, you'll have to get off your chair and go for a drive around to each site.

There's no database you can look up as the list of LAC/CID codes are accessible only by carriers and government for network planning.

 

Generally yes.

If you do not have 'line of sight' to the cell tower (i.e. there are hills in the way), your connection relies on radio waves bending over terrain - a phenomena known as diffraction.

If you imagine the wall in the above image as a hill, the closer you are to the base of the hill the further you sit in its shadow.

In order to capture a stronger signal we'd either have to move further away from the hill, or move vertically upwards - in both cases, we're trying to reduce the angle from the tip of the hill to our antenna.

It's not always possible to move away from the base of the hill, so we must raise the antenna higher! Learn more by reading our Guide to Understanding Poor Mobile Network Coverage

 

Yes.

Without getting too technical, a stronger, cleaner signal allows your modem to negotiate a faster rate of information transfer.

The cleaner connection results in a lower Bit Error Rate (BER), which allows us to reduce the amount of required redundant information sent to protect against errors.

Because some cell towers are faster than others, a directional antenna can be a handy tool to choose between towers - allowing us to select a faster tower, a less congested tower, or a tower with a lower ping.

For those using Telstra, the mobile broadband coverage map depicts the different tower speeds by different colours.

 

Not usually - but it depends!

Ping (connection latency) is inherent to the path taken by each packet of information through the network, and is incurred during each 'hop' through the network hardware (each packet must be read to determine its destination), and during the time spent in the air or in the wires - travelling just under the speed of light.

Using an antenna cannot make this information travel any faster, nor can it make the network hardware route the information any quicker.

However, if there is a choice of cell towers in your area, it is possible to use a highly directional antenna to pick and choose which tower to connect to - this can reduce latency by allowing your modem to connect to a tower that has a faster Internet connection (some cell towers transmit their information over slower microwave backhaul rather than optical fibre).

Sometimes the answer is yes. If your connection is extremely bad - so bad that data packets are getting corrupted to the stage they must be retransmitted, an antenna will probably reduce latency by reducing retransmission rate as well as reducing decoding time.

Note that for most reasonably stable connections this is not an issue, as most bit errors can be corrected via FEC without requiring retransmission.

 

Generally yes.

While your connection will continue to vary in speed as more people start and stop using the cell tower, an antenna should increase the overall speed.

By improving radio conditions we're reducing the amount of redundant information sent by the cell tower to ensure the modem can correct errors (FEC) - imagine having to constantly repeat yourself in a conversation to ensure everyone heard what you had to say.

Essentially, while we may not be able to transmit any additional bits per second, with an antenna we can transmit more bits of useful information per second.

This is known as increasing the coding rate (or Shannon entropy rate).

 

Yes.

Most WCDMA networks employ a technique known as "cell breathing" to decrease their geographical coverage area in order to offload traffic onto nearby cell towers.

This can cause issues for users on the fringe of mobile reception where there are no nearby cell towers, resulting in a decrease in signal strength or disconnection.

Because WCDMA users share a single carrier frequency, cell breathing is required to maintain SINR ratio to ensure code division remains possible.

LTE does not suffer from cell-breathing issues as multiplexing is performed via OFDMA (users are assigned separate carrier frequencies) and hence SINR is not impacted by the presence of other users.

 

Yes.

You may have noticed that your battery lasts much longer when you're close to a phone tower - this is because your phone doesn't need to constantly broadcast at full strength or search for a connection, it can transmit at just the right amount of power to achieve a good signal and conserve battery.

Increasing signal strength with an antenna means your phone or modem can reduce the amount of transmission power required to connect with the cell tower.

 

Unless you're using the modem on 4G, then no.

When in 3G/Next-G mode the second port on your modem is a 'receiver diversity' port.

Receiver, or Rx diversity is achieved by connecting a second antenna to your modem and positioning the antenna away from the first. In areas with no line of sight, signal must bend or bounce over hills and objects to reach your modem, causing the signal to become scattered.

The physical separation of the two antennas helps 'put back together all the pieces', in a manner of speaking.

Our experience suggests there is rarely a noticeable improvement.

When using 4G, your modem will engage MIMO "Multiple In, Multiple Out" and use the second antenna to double the maximum data rate.

For a more detailed explanation please check out our Guide to 4G

 

This depends on the bandwidth of the antenna - most 'CDMA' antennas are tuned to the lower half of the 800MHz band.

This is problematic because the receiving frequency for a Telstra Next-G phone or modem is actually 877MHz or 885MHz.

Having a receiving frequency of 840MHz, your CDMA antenna might transmit well on Next-G, but it may struggle receiving signal.

 

You'll often see this performed in most installations, and while looping coaxial cable has no electrical benefit, it is useful for relieving gravitational stress and also forms a drip point for water.

Leaving additional cable is also a handy idea for future modifications.

Mobile phone base stations must comply with strict safety regulations. The signal strength of a base station can be calculated at different height levels, using the ARPANSA EME Environmental Report.

This report provides information about the levels of EME from the site as a percentage of the mandatory public exposure limit.

Typically ground exposure is about 0.15% of the public safety limit, those working in multi-storey buildings that have cell panels installed are most exposed, but still only at a rate as high as 2% in the worst case.

For more information about RF exposure please see the following fact sheets

• Multi-Storey Building Exposure

• Rooftop Cell Towers

• Your Health & Cell Towers

 

 

Unless you have a multiband antenna, there's a high chance your antenna is tuned to a particular frequency.

This means that the design of your antenna has been optimised for a particular range of frequencies.

Transmitting a frequency outside this range will cause a larger portion of power to be reflected back down the cable and into your phone or modem - this is referred to as VSWR "Voltage Standing Wave Ratio".

While a very high VSWR can actually damage radio equipment, it most commonly results in the garbling of transmitted information (increasing bit error rate).

During design, the construction of the antenna is continuously adjusted to minimise the amount of reflected power, ensuring VSWR is as low as possible (generally under 1.5:1 is an ideal ratio) for the target range of frequencies.

Finding an antenna design that affords a low VSWR and a high gain on multiple bands is extremely challenging.

 

No.

A cell tower transmits every call and text message for every phone in the area simultaneously, but each are encrypted/decrypted with a code generation algorithm that is linked with the destination phone number.

Your SIM card has a copy of the corresponding decryption/encryption generation algorithm, meaning that only your SIM card can decrypt your phone call and nobody else's call.

GSM based cell phones (older 2G networks) use a 64bit A5/1 stream cipher which can be cracked with a ciphertext-only attack - i.e. intercepting the transmission and cracking without having access to the SIM card.

While not used by in 3G mode, carriers such as Vodafone and Optus often fall back onto GSM networks when outside 3G areas.

Cracking A5/1 is extremely difficult - so there's no legitimate cause for concern, unless you've made enemies with Ph.D-wielding cryptanalysts - eek!

Anyway, 3G/Next-G uses a much more secure 128-bit A5/3 "KASUMI" stream cipher. There are no practical attacks on this encryption algorithm. However, it should be noted that network providers work closely with law enforcement agencies, providing unencrypted access upon request.

Bluetooth is also NOT secure. Most Bluetooth devices are paired using a default pin of '0000', this pin is absolutely necessary to secure your phone call over the short range 2.4GHz network used in Bluetooth communication.

If this pin is not changed, anyone with a 2.4GHz antenna can listen in on your phone call (provided they have the technical know-how).

 

No.

Antennas simply pick up radio waves in the air, which travel down the cable and into your phone or modem - nothing complex is required.

Amplifying a mobile phone or modem signal using AC power is illegal and carries heavy penalties under the Radiotelecommunications Act 1992 (Cth).

 

Your Subscriber Identity Module or SIM, uniquely identifies your device on your carrier's network.

This SIM card attaches a mobile phone number to your phone or modem so you can make and receive calls, send text messages and access packet based services such as 3G Internet and MMS.

A cell tower transmits every call and text message for every phone in the area simultaneously, but each are encrypted/decrypted with a code that is linked with the destination phone number.

Your SIM card has a copy of the corresponding decryption/encryption code, meaning that only your phone can decrypt your phone call and nobody else's call.

 

Transmission power is controlled by the cell tower in the form of small Transmit Power Control (TPC) messages.

TPC is used to ensure the phones transmission power is maintained at a Signal to Interference (SIR) target.

This important metric helps your phone use the least required amount of battery power.

Maximum transmission power depends on the power class of your mobile phone.

You can find your device's power class on its technical specifications sheet.

WCDMA Power Classes

Class 1: 33dBm (2W) Class 2: 27dBm (500mW) Class 3: 24dBm (250mW) Class 4: 21dBm (125mW)

 

This will depend on radio technology used.

See below for WCDMA.

NodeB Rx sensitivity: -121dBm Mobile phone Rx sensitivity: -117dBm at BER = 10^-3

 

Carriers like Telstra and Optus use network engineering programs such as AToll and RFMap2 to plan out each cell tower, or 'node' as part of the larger 'mesh' network of towers.

Radio Propagation modelling is used to determine the optimal location for each cell tower based on the area it must cover.

However, because each new cell tower interferes with all the surrounding towers, it must be positioned in a spot that covers an area the best it can, without causing radio interference with another tower.

Radio interference and coverage area can be optimised by raising or lowering the antenna height, mechanically tilting the antennas down (to create a micro cell - i.e. increase capacity) or up (to increase coverage area or reduce the impact of terrain).

Programs like AToll assist in the decision making process by factoring in terrain and other geographic disturbances to locate a position for the tower that optimises coverage area, reduces black-spots, and minimises interference.

Other factors that come in to play are cost minimisation, access to backhaul networks, and aesthetics.

Expenditure costs are often reduced by locating cell antennas on top of tall buildings, light poles, power lines, just about any tall object you can imagine.

Viability is also assessed by modelling income generated, where income is the result of the number of customers serviced. This is important to justify the $150,000 (avg.) capital outlay required to construct the site.

Aesthetics is important in metro areas where conventional monopoles are considered an eyesore, sites where antennas are hidden or painted to blend in are often called 'stealth' sites.

 

Myth: Complex passwords are harder to break.

Most complex passwords have predictable patterns (such as capitalising the first letter, interchanging 'e' for '3' or 'o' for '0') and therefore can be described by a number of 'rules'.

Rule-based analysis is used by most forms of brute-force/cracking software to filter down or prioritise the type of passwords to attempt first.

The idea behind introducing additional characters is to increase the 'key-space' - for example, a three letter password using characters a-z has a key-space of 15,600 possible permutations.

Compare this to a three letter password using characters A-Z, a-z, and 0-9 which has a key-space of 226,920.

Sound secure? Think again.

An entry level graphics card, such as a Radeon HD6970, can perform 129,600,000,000,000 SHA-1 attempts to crack a code in one day (using a GPU enabled software package like oclhashcat).

However - the easiest way to increase key-space is to simply increase password length.

Some of the strongest passwords are a simple concatenation of a few words. eg. "coffeebeantreemonkey" easy to remember, difficult to crack.

 

Delivery Information

All small items (under 1m) are sent via Australia Post / Star Track depending on the location and item quantities.

Large items and orders containing multiple products (over 1m) are sent via Star Track Express.

Overseas orders are despatched with DHL Express.