FAQ
Q. What is an ADSL2+ in-line filter?
Q. What gives ACS filters the edge?
Q. I presently have downstream line attenuation of about 40dB. Will your filters improve this?
Q. What equipment should be temporarily disconnected to perform an isolation test?
A. ADSL2+ is a second generation 'broadband over telephone line' technology that has been specifically designed to improve the data rate and reach of first generation ADSL. It uses twice the bandwidth of ADSL broadband and so has the potential for much higher data speeds. It exhibits better performance on long lines in the presence of narrow band noise. This is accomplished by improving modulation efficiency, reducing framing overhead, achieving higher coding gain and providing enhanced signal processing algorithms.
Q. What is an ADSL2+ in-line filter?
A. ADSL and ADSL2+ are technologies that allow high speed internet and email access (broadband) via the same wires that are used for your telephone. This means that if you have a fixed line telephone then in most cases it is connected directly back to the local telephone exchange and this connection can be used simultaneously and independently by the telephone and ADSL or ADSL2+ broadband systems.
However to be independent, ALL existing analogue telephone equipment must be unplugged and reconnected through an ADSL or ADSL2+ in-line filter. This means that anything that was previously connected to the telephone line before the ADSL or ADSL2+ broadband was installed: telephones, answering machines, fax machines, alarm systems, pay TV dialers, computer dial-up modems etc must be connected via the fax/telephone socket of an ADSL or ADSL2+ filter with the line side of the filter connected to the original socket.
If they are near each other, multiple pieces of analogue telephone equipment can share the one ADSL2+ in-line filter using double adaptors on the telephone side of the filter. If you require more than 3 ADSL2+ in-line filters to 'isolate' all of your existing analogue telephone equipment or if you have a type of alarm system or fax machine using what is known as a Mode3 connection, then you will need to have an ADSL2+ Central Filter installed by a qualified technician.
A. Yes. Advanced Circuits and Systems 900E2+ Series ADSL2+ filters are genuine ADSL2+ filters, designed in Australia to the new Australian Standard AS/ACIFS041:2005. Designed from the ground up for the full bandwidth (2.2MHz) ADSL2+ performance and noise free operation in the presence of live ADSL2+ signals. These designs are backed up by two Australian Innovation Patents as well as further National and International Patents pending.
Existing filters designed to the first-generation ADSL standards, such as RCIT.0004, are certified to only half the bandwidth and not tested for noise in the presence of live ADSL2+ signals. They can be released to market before it became mandatory for AS/ACIF S041:2005 compliance and simply renamed as ADSL2+ filters.
Only AS/ACIF S041:2005 certified filters are genuine ADSL2+ filters. Look for 'Certified to AS/ACIF S041:2005' on the packaging.
Q. What gives ACS filters the edge?
A. ACS filters incorporate a number of design features, some patented, to provide excellent isolation of telephone equipment resulting in high performance of both the ADSL2+ broadband and telephone systems. These include:
- A clean LC first stage with wide dynamic range and free of static generating switches.
- A patent pending second stage solid state switch with full overvoltage circuit protection.
- Coupled inductors are clamped not taped, so precision gaps (and therefore inductance) cannot change over time.
Other filter manufacturers have been successful at removing static under ADSL2+ signal conditions by removing the overvoltage protection of their solid state switches. However, over time, unprotected sensitive solid state devices will degrade with a gradual (or worse) deterioration in noise and speed performance.
The result is that ACS filters are not only certified to AS/ACIF S041:2005 but also designed to give you fast, reliable, stable and noise free connection to your ADSL2+ line.
A. Yes. The quality of your ADSL2+ connection will only be as good as the worst link. It takes only one telephone, fax or dial up modem that is NOT connected through a filter to degrade your ADSL connection quality. A single telephone connected directly to the line without going through a filter can stop an ADSL2+ modem from synchronising
A. Again, your ADSL2+ connection will only be as good as the worst link. Non-S041 filters, such as RCIT.0004 first-generation or older ADSL filters, have not been certified for the full bandwidth of ADSL2+, nor have they been tested live with ADSL signals to guarantee that they generate no interference on a telephone, fax or modem.
A. You have 2 options:
A) Engage an authorised telecoms technician to install a single ‘central’ filter at the point of entry to your house then you can connect all of your telephone devices subject to the REN not being exceeded.
B) If you have two or more devices connected to the telephone line at the one location such as a dial-up modem and telephone at a work desk then you can connect the LINE IN to the 900 series in-line filter LINE IN terminal and then use an RJ6 male to two female double adaptor to then feed your computer dial up modem and desk telephone.
A. Conditionally yes. Models 901E2+, 905E2+, 921E2+ and 931E2+ all connect directly a second pair of wires on the outer 2 pins of the 4 connected pins between the 'LINE' and 'FAX/TEL' RJ connectors. However, wiring can be complicated and it is most likely that some fixed wiring will need to be altered such as the installation of an 'ADSL' dedicated cable and so it is recommended that an ACMA licensed cabler be employed to perform the installation.
A. Yes. Our filters are also suitable for most Alarm systems that communicate back to base in the voice frequency band.
A. The answer is probably yes, since the ADSL2+ system will be degraded by connections that do not appear ideal to the high frequencies used. The use of good quality cable, such as Cat5, which contains twisted pairs intended for high speed data, connected directly from the point of entry of the telephone line to each ADSL filter and telephone device will give the best performance.
Cable that contains more copper, such as figure-8 types, may seem to be an attractive option to reduce voltage drop, but since it is not ‘twisted’ and does not have the correct impedance it is not suitable for Telephone lines carrying ADSL signals.
A. No. The most important characteristics controlling your final download speed are line length and quality from the telephone exchange. Our filters can and do improve the characteristics in your house to optimise your connection speed and reduce noise on both the telephone and ADSL systems.
However, they cannot compensate for the attenuation experienced by the signal or poor connections in the line on its way to your house.
Q. I presently have downstream line attenuation of about 40dB. Will your filters improve this?
A. Generally No. The most important characteristic controlling your line attenuation is line length. ADSL(2+) filters are connected between the pre-existing analogue telephone equipment and the incoming line. The ADSL(2+) modem is connected directly to the incoming line and so line attenuation is essentially unchanged as a result of filters being attached.
A. Yes, first generation ADSL broadband is essentially a subset of the newer ADSL2+ and therefore the benefits of reduced noise and optimised connection speed enjoyed with ADSL2+ when using an ACS 900E2+ series filter will apply to your ADSL broadband, although to a lesser degree.
A. An isolation test is sometimes requested by your ISP as a way of identifying whether there is any mal-functioning hardware other than your ADSL modem connected to your telephone line in your premises. It is accomplished by temporarily disconnecting all equipment from the telephone line except for your ADSL modem, then operating your ADSL connection.
Any significant improvement in performance can then indicate that one of the removed pieces of telephone/ fax/ dial-up modem/ foxtel dialler/ alarm dialler is either mal-functioning, has not been connected through an ADSL filter or is connected to an ADSL filter that is itself causing problems.
NOTE: Your fixed line telephone will not be working during an isolation test and so it is important to reconnect at least one telephone via an ADSL(2+) filter at the conclusion of the test.
Q. What equipment should be temporarily disconnected to perform an isolation test?
A. All telephone line connected equipment except for the ADSL modem. This includes any ADSL filters which should be disconnected at the 'Line In' connection. Many non-ADSL2+ filters can generate noise in the presence of ADSL2+ signals and so should be disconnected to perform an isolation test.
All other analogue telephone equipment such as telephones/ fax/ dial-up modem/ foxtel dialler/ alarm diallers should already be disconnected when their ADSL filter has been disconnected via the 'Line In' connection but if in doubt, temporarily disconnect any device connected to the telephone line to perform the isolation test.
NOTE: Your fixed line telephone will not be working during an isolation test and so it is important to reconnect at least one telephone via an ADSL(2+) filter at the conclusion of the test.