3. The Technology

Readers familiar with my Corinex CableLAN review a little over a year ago, may remember that that product used an Intellon INT51MX SIMPLE (Single Inline Module PowerLine Enabled) HomePlug 1.0 module coupled to a coax cable interface. Because of this base technology, top throughput was only about 6Mbps or so - hardly enough to support video streaming.

This time, Corinex has turned to HPNA 3.0 technology in the form of CopperGate's CopperStream chipset as the heart of the AV Phoneline and AV CableLAN adapters. This means the AV Phoneline product is HomePNA 3.0 compliant since it's a straight HPNA product. But since the AV CableLAN doesn't have a phoneline interface, it's really a product that doesn't comply with any standard.

For their AV Powerline adapter (which I won't be looking at in this review), Corinex instead opted to use technology from Spanish powerline networking company DS2. DS2 made quite a splash at this January's CES with its 200Mbps non-HomePlug chipset and together with Corinex and others the formed a new powerline networking industry group, the UPA (Universal Powerline Association).

Figure 1: AV Phoneline board
(click on image to enlarge)

Figures 1 and 2 show the AV Phoneline and AV CableLAN boards respectively. The CopperGate CG3011 digital chip forms the heart of each board and provides MAC, Data Link, Convergence and Management networking functions. But instead of Coppergate's companion CG3012 AFE (Analog Front End) chip, both products instead use an Analog Devices AD9865 - 10-Bit Broadband Modem Mixed Signal Front End.

Figure 2: AV CableLAN board
(click on image to enlarge)

A check of both devices' block diagrams, however, show both include separate A / D and D / A converters plus associated programmable filtering. On the bottom of both boards is an

Feedback I received from the original CableLAN review showed some confusion regarding the product, with some readers thinking the product was similar to old coax-based 10Base2 Ethernet, commonly known as "thinnet". Although both networking methods use coax cable, they represent very different approaches and use entirely different technology.

10Base2 used 50 ohm coax in a dedicated terminated environment that had to be connected in linear bus topology and had a maximum raw data rate of 10Mbps. Anyone who lived through the thinnet era remembers what a pain it was to diagnose connection problems and find bad connections and missing (or too many) terminators. But it sure beat using 10Base5 "thicknet" cable along with the vampire taps and heavy AUI cables that went along with it.

The Corinex AV CableLAN uses CopperGate's technology, which I'm guessing uses OFDM and some fancy signal processing to achieve its 128Mbps maximum raw data rate. More importantly, the AV CableLAN system is intended to be connected to home cable TV coax systems, which can have all sorts of splitters and pretty messy topologies and have live cable TV and cable modem signals also present. So while both systems use coax cable, they are worlds apart in their approaches to moving data around your home.