Ad
related to: adsl frequency
Search results
Results From The WOW.Com Content Network
Modern ADSL filter/splitter (left) and filter (right). ADSL works by using spectrum above the band used by voice telephone calls. [1] With a DSL filter, often called splitter, the frequency bands are isolated, permitting a single telephone line to be used for both ADSL service and telephone calls at the same time.
ADSL2+ extends the capability of basic ADSL by doubling the number of downstream channels. The data rates can be as high as 24 Mbit/s downstream and up to 1.4 Mbit/s upstream depending on the distance from the DSLAM to the customer's premises. ADSL2+ is capable of doubling the frequency band of typical ADSL connections from 1.1 MHz to 2.2 MHz.
Discrete Multi-Tone (DMT), the most widely used modulation method, separates the ADSL signal into 255 carriers (bins) centred on multiples of 4.3125 kHz. DMT has 224 downstream frequency bins and up to 31 upstream bins. Bin 0 is at DC and is not used. When voice is used on the same line, then bin 7 is the lowest bin used for ADSL.
Digital subscriber line (DSL; originally digital subscriber loop) is a family of technologies that are used to transmit digital data over telephone lines. [1] In telecommunications marketing, the term DSL is widely understood to mean asymmetric digital subscriber line (ADSL), the most commonly installed DSL technology, for Internet access.
ITU G.992.3 is an ITU (International Telecommunication Union) standard, also referred to as ADSL2 or G.dmt.bis.It optionally extends the capability of basic ADSL in data rates to 12 Mbit/s downstream and, depending on Annex version, up to 3.5 Mbit/s upstream (with a mandatory capability of ADSL2 transceivers of 8 Mbit/s downstream and 800 kbit/s upstream). [1]
The various forms of digital subscriber line (DSL) services are broadband in the sense that digital information is sent over multiple channels. Each channel is at a higher frequency than the baseband voice channel, so it can support plain old telephone service on a single pair of wires at the same time. [11]
In order to combine voice telephone service with downstream and upstream ADSL signals the bandwidth is split into discrete parts using frequency-division multiplexing (FDM). In this case: 0–4 kHz is for voice, 26–138 kHz is the upstream band and 138–1104 kHz is the downstream band.
Downstream ADSL/ADSL2 Additional Downstream ADSL2+ The main difference between this specification and Annex A is that the upstream/downstream frequency split has been shifted from 138 kHz up to 276 kHz (as in Annex B/ Annex J ), allowing upstream bandwidth to be increased from 1.4 Mbit/s to 3.3 Mbit/s, with a corresponding decrease in download ...