Hack 11 HPNA and Powerline Ethernet
These nontraditional networking protocols can
save you a ton of effort.While not wireless networking protocols per se, both HPNA and
Powerline Ethernet are finding their way into many
people's network scheme. Like wireless, they both
provide network functionality without requiring the installation of
CAT5 cable. But rather than use wireless, they use other common media
for their physical connection.
HPNA
HPNA stands for
Home Phone Networking
Alliance
.
It provides networking capabilities over
existing CAT3 cable, and can share the same wire as a standard
telephone line (even if you are using DSL on the same line). HPNA can
reach about 1,000 feet over CAT3. The original HPNA 1.0 products can
communicate at about 1.3 Mbps, while the newer HPNA 2.0 standard
allows for speeds of up to 32 Mbps (although devices operating at 10
Mbps are more common). Some consumer grade routers, such as 2Wire
HomePortal 100W, incorporate Ethernet, HPNA, and 802.11b in one unit.
Pros
Instant networking in any building with existing telephone wiring.Very simple installation; just plug it in and you're
done.Fairly inexpensive.
Cons
HPNA isn't nearly as popular as Ethernet or
Wireless, so it can sometimes be hard to find in retail stores.HPNA 1.0 is much slower than wireless, but HPNA 2.0 approaches speeds
of 802.11b.Every HPNA device uses the telephone line as a shared medium, making
it less efficient than a network switch as more devices are added.
Recommendation
HPNA can be ideal for adding access points to additional locations in
a house or building that doesn't have CAT5
Ethernet laid to each room. Dedicated
Ethernet is better for speed and reliability, but HPNA can make your
job much easier. If you need to add additional access points to a
building for greater coverage, or you want to shoot
"through" a building by adding a
device with external antennas on opposite walls, then HPNA can save a
great deal of effort when tying it all together.
Powerline Ethernet
Powerline Ethernet uses
AC power lines as a physical medium for
network traffic. Powerline devices are about as simple as they come;
simply plug in a CAT5 cable to one side of the device, plug the other
end into any wall outlet, and you should be up and running. Some
devices support encryption on the devices, but this is hardly ever
necessary. Powerline Ethernet won't cross a power
transformer, so your network signal usually stops at the end of your
house wiring.Siemens, Linksys, and NetGear all
make popular Powerline adapters that should interoperate well with
each other. They advertise speeds of up to 14 Mbps, but actual data
rates of 5 or 6 Mbps are typical. As with HPNA, Powerline is a shared
medium, much like a networking hub. More devices means more possible
collisions and lower throughput.
Pros
Very simple installation, with virtually no configuration needed.Data speeds comparable to 802.11b.Ethernet bridges mean no configuration at all on the computer side.
Cons
Slightly expensive as of this writing (typically $100 per device,
with at least two devices required).
Recommendation
Much like HPNA, Powerline Ethernet can be ideal in situations where
CAT5 wiring just
isn't practical. This can make installation much
simpler whenever you have an AC outlet handy but
can't quite get to a telephone line or CAT5 cable.
There is no configuration needed in most cases, as the Powerline
bridge acts just like a network hub to your Ethernet devices.While CAT5 is usually preferred over line-sharing protocols such as
HPNA and Powerline, these devices can save you a tremendous amount of
installation time and effort. If you can cope with the slower data
rates and slightly higher cost (compared to Ethernet), then these
devices might be a perfect component for your wireless networking
project. |
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