[mythtv-users] Wireless Pre-N for Linux?
gchris at bellsouth.net
Mon Mar 26 16:49:40 UTC 2007
On 3/26/07, Jarod Wilson wrote:
>> On 3/25/07, William Munson <william_munson at bellsouth.net> wrote:
>>> > > Ken Mandelberg wrote:
>>>> > > > My 802.11G wireless setup is just two slow for HD between the front and
>>>> > > > backends. Are their Pre-N solutions with Linux drivers (USB, PC card
>>> > >
>>> > > nics)?
>>> > > There are a number of wireless solutions for linux however its still not
>>> > > going to allow you to view HD over a wireless network. 802.11G is just
>>> > > not fast enough. From what I can see, the only option is cat5/6 cable.
>> > Will 108Mbit do it? With a matching (D-LINK) wireless router, the D-Link
>> > DWL-820 will do 108Mbit. It's a wireless gaming adapter that plugs into
>> > the ethernet port, so it doesn't need drivers.
>> > http://www.mythpvr.com/mythtv/hardware/wireless_gaming_adapter-802.11g.html
>> > I use it with a standard 54g network, so I can't really speak to the 108
>> > aspects, but it says it does it. I use mine for a SD MiniMyth frontend.
> You might have better results with the supposed 108Mbps stuff. I'd suggest
> trying a file transfer benchmark. Simply scp a large file over your
> connection and see what sort of throughput you get, taking note along the way
> of any stalls, drops in speed, etc.
>> > Come to think of it 108Mbit is higher than 100Mbit, so looking at the raw
>> > numbers, your 100Mbit ethernet would be the bottleneck. In practice, I bet
>> > the wireless has overhead that eats up a chunk of the bandwidth before
>> > getting to ethernet. Hmm...not like it really matters.
> Wireless bandwidth claims are a joke -- more marketing bullshit than fact.
> Unless you have a clean line of sight and zero interference, good luck
> getting even *half* of the supposed throughput. I've got an 802.11g bridge at
> home, Linksys WAP54G as the base station on the main floor, Linksys WRT54GS
> as the bridge device upstairs, not much in between them but the
> ceiling/floor. Very typical setup someone would have in a home, and I can't
> get anything better than about 20Mbps sustained throughput.
There are some additional considerations. The D-Link 108Mb adapters
require two clear channels and an unimpeded path to come close to
achieving their rated speed. Even if the adapters have a clear line of
sight between them, interference from a neighbors wifi network can make
108Mb iffy, and my experience with these cards suggests that only a
small improvement over 54Mb cards is the norm.
Using an external game adapter or a spare router configured as a network
bridge works better for two reasons. Placing a wifi adapter inside your
backend can desensitize some TV capture cards. My HD3000s see reported
signal strength drop 8-12% when a D-Link DWL G520 is installed next to
them in the backend. Also, an external wifi adapter allows you to
optimize antenna placement in ways that are impossible when you've got a
card plugged inside the box and it also saves a slot and reduces power
and cooling requirements. Beware of game adapters that use a USB
connection because Linux drivers are not easy to come by for that kind
I used a D-Link DWL-G132 USB dongle very successfully for SD with a Suse
box and Linuxant drivers. Unfortunately, Fedora kernels use a small 4k
stack size which is not amenable to the Linuxant drivers.
Bottom line, a wired connection is still the cheapest and most reliable
connection for distributing HD.
More information about the mythtv-users