|At a glance|
|Product||Zyxel 1000 Mbps Powerline Gigabit Ethernet Adapter (PLA5206KIT) [Website]|
|Summary||"1000 Mbps" HomePlug AV2-SISO adapter kit based on Broadcom's BCM60333 chipset|
|Pros||• Seems to try to work around noise sources|
• Can provide 300+ Mbps of total throughput with multiple traffic sources
|Cons||• Huge up and downlink throughput difference when running bi-directional traffic|
• Expensive compared to better performing alternatives
While we await the first HomePlug AV 2 MIMO adapters, ZyXEL has released its PLA5206 1000 Mbps Powerline Gigabit Ethernet Adapter. Like many powerline adapters, the new ZyXEL is available only in a kit of two as the PLA5206KIT, which will currently run you about $130.
Let's establish right away that this is not an AV 2 MIMO adapter. Using official HomePlug AV 2 Profile nomenclature shown below, the PLA5206 supports the SISO 750 Mbps profile (SISO-750 for short).
HomePlug AV2 Profiles
So how can ZyXEL claim 1000 Mbps for a product designed to a "750 Mbps" profile? Here is ZyXEL's explanation:
- Broadcom HPAV2 SISO device can use a bandwidth of up to 84.3 MHz (from ~1.8 MHz up to ~86.1 MHz).
- In this bandwidth, a total of 3455 OFDM carriers are employed with a minimum symbol time of 40.96 us
- The maximum bit allocation per carrier is 12
- The maximum PHY rate is obtained as follows: 3455 carriers x 12 bits/carrier ÷ 40.96us = 1012.2 Mbps
This is clearly a theoretical calculation of raw bit rate, which will never be reached in real world use. It also begs the question of why the "official" AV 2 profiles have the numbers they have. But they are what they are.
Since I'm a fan of standards, I'll be using the profile nomenclature in the above table going forward to identify these products in our Charts, Finders and other product research tools.
The PLA5206 is larger than most HomePlug adapters I've seen lately. But the two-prong plug placement positions the adapter body so that it won't block the adjacent outlet in a standard U.S. duplex, as shown in the photo below. The serial number label specs a 100 - 240 VAC operating range.
ZyXEL PLA5206 plugged in
The callout diagram below shows the adapter supports tri-color HomePlug link quality indication. The single Gigabit Ethernet port is centered on the bottom side of the adapter, with the Reset / Encryption button sitting to its left as shown in the opening product shot above.
ZyXEL PLA5206 callouts
The User Guide says the adapter goes into power-saving mode after 60 seconds of Ethernet inactivity and powers up again when activity resumes. I verified this by the following procedure, which ran without a hitch.
- Plugged in two adapters, let them link up and started a long ping from the HomePlug connected machine to another machine on my Ethernet LAN.
- Unplugged the cable connecting one adapter to my LAN switch. Verified that ping showed no response.
- Waited until the Ethernet unplugged PLA5206 entered power-save.
- Plugged Ethernet back in and verified that adapter powered up and ping returns resumed.
Broadcom has been largely absent from the HomePlug market, despite buying Gigabit powerline pioneer Gigle back in 2010. The only other Broadcom-based powerline products we've tested were Linksys' PLE400 and PLS400 back in 2012.
So the ZyXEL PLA5206 is a HomePlug AV2 coming-out party of sorts, since it uses Broadcom's BCM60333, which the company announced over a year ago.
The inside photo clearly shows the BCM60333, which is coupled to the sheet-metal thermal spreader in the top cover via the thermal pad stuck to the spreader. The small device below the BCM60333 is a Microsemi Le87401 PLC Single Channel Line Driver designed for use in HomePlug AV2, G.HN and MoCA devices.
ZyXEL PLA5206 inside
It's interesting to note that the Broadcom device fills a hole in QCA's product offerings, shown in a table borrowed from the HomePlug AV2 Head-to-Head.