D-Link DHN-910 Phone Networking Kitby Greg Hanna on February 10, 2000 7:04 PM EST
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D-Link is one of several manufacturers that have released a product based on the recently ratified HomePNA 2.0 standard. HomePNA (Home Phoneline Network Alliance) is a group of over 100 companies which have come together to produce a single home phonline networking standard. Some of the founders are IBM, AT&T and Compaq. Add to that the fact that several large producers of networking equipment are members (3com, Intel, Cisco, Xircom, etc) and you can be pretty sure that their standard will be the standard. This means that if you buy one company's home phonline network hardware it will almost certainly work with another company's equipment.
The technology itself is not new. It has been used by telephone providers for many years to provide two separate telephone 'lines' when only one pair of physical wires is available, and is the same technology behind ADSL. The basic premise is that you can pass several signals over the same pair of wires using separate frequency ranges. Your phone conversation, for instance, is passed at relatively low frequencies (4kHz and below) and is not actually even the same kind of signal used by ADSL or HomePNA. The two latter technologies use a much higher frequency range (up to 1.1 MHz in the case of ADSL) and are modulated onto the carrier frequency using shifts in phase and amplitude. The upshot of all this is that your telephone wire can handle a voice conversation, ADSL data, and HomePNA data all at one time, with no disruption or interference between them.
The new 2.0 standard boasts a peak throughput of 10Mbps, the same as standard Ethernet LANs like you'd find in most offices. This is a significant improvement over the 1.0 standard, which had a peak throughput of only 1Mbps. Although that speed was fine for network gaming and printer sharing, the sharing of large files and the addition of more computers on the home network (HomePNA networks can currently handle up to 25) has made the jump to 10Mbps necessary. Large files transfer up to 10 times as fast, and the increased bandwidth of the new standard allows more computers to use the network simultaneously without killing the speed.
One very important note: Since HomePNA is a standard, older 1.0 equipment and new 2.0 equipment will work together just fine and, also, any new specifications put out by HomePNA will be backwards compatible with the existing standards. This ensures that you won't absolutely have to change your equipment every time a technology breakthrough happens.