G.hn Home Networking Overview

G.hn provides an evolution from the various wired home networking technologies like MoCA, HPNA, and Homeplug to provide what is intended to be a universal standard for wired communications within the home. Targeted to support rates of up to 1 Gbps, G.hn supports high data rate networking over the commonly available wired media already installed in many homes.  This includes power lines, cable tv coax, and twisted pair phone lines (of course, it has separate implementations for each medium). It supports physical data rates up to 1 Gbps and is being developed by the ITU-T and the HomeGrid Forum, among other organizations.  The diagram below shows all the different ways G.hn can network a home.

X.1035 is used for authentication and key exchange in G.hn networks.  AES-128 encryption with G.hn is point-to-point, and each set of communicating endpoints requires a unique AES key.

Unlike the original Ethernet protocol which was unable to guarantee access to any one terminal, G.hn uses Time Division Multiple Access (TDMA) for granting access to the medium over which it is transmitted.  With TDMA, bandwidth is reserved for each set of communicating terminals, so G.hn can provide QoS to applications that require it. Additionally, a transmitting G.hn terminal can use another G.hn terminal to relay messages to a third G.hn terminal not reachable directly from the first one.  This doubles the distance G.hn can serve, though it does add some complexity to its implementation.

Work on the G.hn standard began in 2006, and the standard is expected to be complete by late 2009. Chips supporting the standard are expected in 2010.  Best Buy, BT, CopperGate, DS2, Ikanos, Infineon, Intel, and Panasonic are some of the major supporters of G.hn. CopperGate, Ikanos, and DS2 are working on G.hn chipsets. Intel is a big supporter of G.hn, as both the President and the Co-Chair of the HomeGrid Forum are Intel employees.

G.9960, specifying the G.hn physical layer and architecture, achieved consent in late 2008.  The HomeGrid Forum is developing test programs for the standard that cover compliance to the standard and interoperability between vendor equipment. Additionally, three other home networking organizations, Consumer Electronics Powerline Communication Alliance (CEPCA), the HomePNA Alliance, and the Universal Powerline Association (UPA) are working with the HomeGrid Forum to develop and promote G.hn.

© 2009, The Product Group LLC. All rights reserved.

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1. admin says:

   October 2, 2009 at 1:37 pm

   Just released today, a good more technical article from the Home Grid Forum… “G.hn: The New ITU-T Home Networking Standard,” at http://j.mp/wEnWs (requires free registration).