Powerline networking can deliver higher and more consistent throughput than wireless, but it can take some tweaking. These tips will show you how to improve your HomePlug network speed.
If you still have original HomePlug (14 Mbps) or even HomePlug "Turbo" (85 Mbps) gear and you're trying to use it to stream HD video, you're fighting a losing battle. Original HomePlug adapters yield only around 5 Mbps of usable throughput (Figure 1).
Figure 1: Linksys PLEBR10 throughput
Linksys Instant PowerLine EtherFast 10/100 Bridge review]
While "Turbo" adapters are able to deliver best case (same room) speeds in the low 20 Mbps range, average room-to-room speeds quickly move down to 10 Mbps or so (Figure 2)
Figure 2: HomePlugTurbo Adapter Throughput results
[from HomePlug Turbo Adapter Round-Up]
Both of these speeds are too low to support the 20+ Mbps required for 720p HD streams. But HomePlug AV (200 Mbps) adapters can deliver best case speeds of 60+ Mbps (Figure 3). Even when degraded by 50%, these speeds are fine for 720 and even some 1080p HD streaming applications.
Figure 3: ZyXEL PLA-400 throughput
Although implied by solution 1, I'll say it explicitly: get rid of older versions of HomePlug adapters and standardize on 200 HomePlug AV. There are two reasons why this is a good idea. First, HomePlug AV can coexist with HomePlug and HomePlug Turbo, but not interoperate.
"Coexist" means that both flavors will work, but only with like adapters. (Actually original HomePlug and HomePlug Turbo will also interoperate, but with reduced performance). But "coexist" doesn't mean that the different generations of HomePlug gear will play nice.
Figure 4 shows around 60% reduction in HomePlug AV throughput when HomePlug Turbo devices become active at the same time.
Figure 4: HomePlug Turbo / AV Coexistence - HPAV first
[from Zyxel PLA-400: Putting HomePlug AV into the game]
No interoperation means you won't get a connection between gear connected with HomePlug AV adapters and those connected with older types.
As is their way, consumer networking companies prefer to create their own branding for products, instead of emphasizing compliance with industry standards. So if you're looking for "HomePlug AV" in product names, you won't often find it.
Instead, you'll find some combination of "Powerline", "AV" and "200" in product names and, if you're lucky and look very closely, some reference to HomePlug AV in small print somewhere on the product box sides or back.
Unfortunately, there are two "200 Mbps" powerline networking technologies: HomePlug AV and DS2 (also sometimes known as UPA (Universal Powerline Association). As you might guess, these two technologies don't play well together. (An example of a DS2 / UPA product is NETGEAR's HDXB101 Powerline HD Ethernet Adapter kit.
Figure 5 shows what happened when I tried to run a pair of DS2 and a pair of HomePlug Turbo adapters that were plugged into my home's outlets at the same time. Note that I wasn't trying to pass data between the HomePlug and DS2 adapters, I was just trying to run them in parallel.
Figure 5: HomePlug Turbo and DS2 battling for bandwidth
[From Corinex AV200 Powerline And CableLAN Set The Pace For Alternative Home Networking]
Figure 5 shows the two technologies battling so badly that neither could operate reliably, i.e. they would neither interoperate nor coexist.
I'm told that changes have been made so that DS2 and HomePlug adapters will now at least coexist and let each other operate. But you'll still suffer performance degradation if both powerline networking flavors are in simultaneous use.