Wireless Home Networking - Index of

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Part IV: Using a Wireless Network
Understanding Wi-Fi Multimedia (WMM)
Another 802.11 standard (man, there sure are a
lot of them) that you might occasionally hear
about (if you’re reading up on 802.11 technologies
online) is called 802.11e. 802.11e is a quality
of service (or QoS) enhancement to other
802.11 technologies (a, b, g, or n) — 802.11e can
determine when bandwidth- or delay-sensitive
traffic is moving across your network (like voice
conversations over a Wi-Fi phone — see
Chapter 13 — or audio/video signals), and it can
then prioritize that traffic over things such as
e-mail to keep your e-mail download from
making your video signal break up on your TV.
The Wi-Fi Alliance folks have created, as
they did with just about all the other 802.11
standards, a certification program for 802.11ecapable
equipment called WMM (or Wi-Fi
Multimedia). WMM-certified equipment incorporates
the QoS mechanisms defined in 802.11e
and additionally has been certified to work
across vendors. If you want WMM to work for
your Wi-Fi entertainment gear, you need to be
sure that both the entertainment device itself
(for example, a digital media adapter) and your
access point or wireless router are certified for
WMM. (The box will have the WMM logo.)
Overall, WMM can help improve your multimedia
experience within your wireless network; one
thing that it can’t do, however, is control the QoS
of your Internet connection. So if your audio or
video network is being affected by traffic inside
your home network, WMM can help — if the bottleneck
is in your Internet connection (for example,
someone downloading a big file while you’re
trying to watch streaming video from the
Internet), WMM won’t be of any assistance.
Choosing Networked Entertainment Gear
The digital media adapters and players we discuss in the preceding section
make a connection between your computer network and traditional (nonnetworked)
A/V gear. Not all A/V gear is incapable of being networked though.
In fact, a growing number of home theater receivers and even televisions are
being outfitted with network capabilities. Most networked A/V gear (be it a
receiver or a TV) simply incorporates a digital media adapter (or the functionality
of one) into the device itself — providing you with the ability to
access digital media files across your home network. Almost all these network-enabled
receivers and TVs are Ethernet devices and not Wi-Fi enabled.
Later in this section, we tell you how to connect Ethernet entertainment gear
to your wireless network.
You can also find whole-home wireless audio distribution systems that can
connect to your computers, but that also can be self-contained wireless
entertainment systems. We talk about both types of systems in this section.