Original URL: http://www.theregister.co.uk/2013/02/15/feature_wtf_is_ieee_1905_dot_1/

WTF is... IEEE 1905.1?

Hybrid, multi-media home networking made easy

By Tony Smith

Posted in Hardware, 15th February 2013 12:03 GMT

Feature It sounds like a solution looking for a problem. A technology that allows networked devices in the home connected by different network media to operate as if they were connected across a single medium. Surely TCP/IP already allows you to do that, routing packets from, say, network attached storage linked to a router over an Ethernet cord across to a TV that might be linked to the router wirelessly or over a powerline bridge?

IEEE 1905.1 may well be searching for a problem to solve, and it may, some observers argue, amount to little more than a standard designed to encourage consumers to buy more kit, but it has some big-name brands behind it and it’s coming to domestic networking hardware soon.

IEEE 1905.1 structure

IEEE 1905.1: unifying multiple networking technologies

At its most basic, 1905.1 specifies the capabilities of firmware that sits just above a network device’s MAC layer. It’s able to seek out other, compatible devices on the network to learn what connections they have available to them and what hosts they’re attached to. Data throughput sampling facilities allow 1905.1 devices to report on the quality of their active links.

The notion is that, say, a TV connected via a router to an online content source will receive that content over whichever network medium it has that is most appropriate. “Packets can arrive and be transmitted over any interface, regardless of the upper protocol layers or underlying network technology,” is how the IEEE puts it. An example: the 1905.1 software in the router might choose to deliver the content - a streamed film, says - to the TV over a Wi-Fi link because that provides the best throughput. Should other wirelessly connected devices join the network and start drawing capacity away from the wireless link to TV, the router can seamlessly switch the television stream to an Ethernet connection instead. Likewise, if one link suddenly drops out, 1905.1 can switch the packets onto an alternative medium.

Purva Rajkotia, chair of the IEEE 1905.1 Working Group, claims this will happen in the order of “a few milliseconds” - not enough time for the viewer to notice the change, he says. Indeed, once the user has set up the TV to connect to the router by both Wi-Fi and Ethernet - whether directly over Cat 5 cable, or by way of a pair of powerline adaptors - he or she shouldn’t need to do anything more to maintain the system - the 1905.1 “convergence layer” does all the work.

Multiple media, aggregated bandwidth

If the TV is only connected by Wi-Fi, 1905.1 can move other devices with access to other media off the WLAN. Even if all the networked devices operate only over wireless links, the IEEE standard’s end‐to‐end quality of service (QoS) provision can give bandwidth priority to the streaming packets bound for the television. Devices with multiple connections can aggregate those connections to boost data transfer speeds.

According to Rajkotia, 1905.1 operates entirely independently from the application layer, so it makes no difference what software and protocols two devices are using to stream a video, play a song or transfer a file, 1905.1 works to route the data over the most appropriate network medium. It doesn’t affect the underlying transport mechanisms. “The P1905.1 layer does not require modification to the underlying home networking technologies and hence does not change the behavior or implementation of existing home networking technologies,” is how the IEEE describes it.

Qualcomm Atheros hybrid network

Wired'n'unwired: the hybrid network
Source: Qualcomm Atheros

In its first version, 1905.1 supports four media: Ethernet; Wi-Fi; powerline based on the IEEE 1901 standard - HomePlug AV, essentially; and co-ax cabling using the Multimedia over Co-Ax (MoCA) specification. A “legacy mode” ensures 1905.1 capable boxes can operate harmoniously with existing network kit, something the service provider backers of the technology were particularly keen on, says Rajkotia, so they don’t need to implement it in one go. That’s also handy for punters putting their own network kit in place.

And 1905.1 doesn’t even mandate the use of all four media in a given device - one is enough, though there’s clearly much less benefit to be gained from the specification’s dynamic media selection abilities if a host gadget doesn’t have at least two types of networking on board.

Rajkotia suggests that future versions of the specification may well add other network media: 60GHz WiGig, soon to gain the Wi-Fi brand, is an obvious contender. Not so the alternative powerline technology to 1901, G.hn. Since the ITU-backed next-gen networking-over-mains-wiring standard is designed to interoperate with 1901, there’s no particular reason why it shouldn’t be supported. It’s un-interoperable specifications that are unlikely to make the grade, says Rajkotia. But with 1901 at the core of 1905.1 and strong support coming from the HomePlug Alliance, it doesn’t seem likely to be granted the chance. Indeed, the HPA is no mere supporter of 1905.1 - it’s the organisation that has been selected to oversee 1905.1 interoperability certification.

Networks at the push of a button

That will begin when the latest version of the specification is formally ratified by the IEEE. Right now, the specification is done and has been placed in the hands of the standards organisation’s pre-publication vetters, who will determine whether it can be published or needs revision. Since the specification has got to this stage in a mere two years - a positively brisk pace for a process that has a reputation for unhurried deliberation - publication of the standard seems likely, which takes us to April.

Kit will follow in May or June, reckons Rajkotia. After all, the spec has been effectively finished since December 2012, and some silicon vendors have already started talking up the technology, most notably Qualcomm Atheros. QA has been promoting what it calls ‘Hy-Fi’ since 2011. Hy-Fi combines QA’s own hybrid networking technology with a draft version of 1905.1, and the chip maker is pitching the system as a mechanism for easy network installation and set-up: the technology is centred on one button the user can push on any compliant network device to allow it to authenticate and configure itself for secure communication with other devices, however they connect to the wired and wireless “hybrid” network.

IEEE 1905.1 home

Think of a powerline-connected Wi-Fi extender. Plug it in, push the Hy-Fi button and the unit not only automatically establishes both a secure link to the powerline adaptor in your wireless router, but it also sets its SSID and WPA 2 settings to match the router’s own WLAN set-up details.

Other chip maker backers include Broadcom, ST Micro and Taiwan’s MStar, while device makers such as Cisco, Huawei, ZTE, Sony and Panasonic have voiced their support for 1905.1 and presumably have compatible kit in the pipeline, though they have yet to go public with their roll-out plans. D-Link has Hy-Fi kit out, as does Europe’s AVM, maker of the Fritz! line of home networking kit. More will follow, now that Hy-Fi taps into 1905.1 so it’ll work with rival hybrid networking products and that 1905.1 is near to becoming an official standard.

Then there are the service provider supporters and they, perhaps more than the OEMs, have been setting the 1905.1 agenda. For example, the specification incorporates provision for remote network monitoring and management, added at the behest of a number of service providers looking to be able to handle tech support work more cheaply. Rajkotia insists this kind of access is voluntary, but service providers are increasingly out to sell complete home networking packages - an extension of supplying a wireless router or a set-top box, say - and will like the idea of configuring and, later, repairing them without having to pay for an engineer to go out.

Doubly so if they can sell this management to less technical users as an optional extra: don’t worry about whether you can set up and run a network, we can do it for you, for a price...

Internet of things

In a similar way, 1905.1 could be viewed cynically as an equipment seller’s charter. Clearly, the specification can’t do its stuff unless there are multiple media connecting devices to the network between which the technology can select the best at any given moment. So are consumers to be now encouraged to go and buy Ethernet or co-ax cabling and powerline adaptors for new, 1905.1-compliant devices which they can almost certainly be able to connect wirelessly?

IEEE 1905.1

That’s why 1905.1 perhaps is a solution seeking a problem: unless your devices maintain more than one network connection, its value is more limited, more so if you’re happy setting up devices’ network settings yourself. But as network adaptors containing Qualcomm Atheros and Broadcom chips are built around 1905.1 compliant silicon, more and more devices will be able to support push-button auto-configuration and hopping between multiple connections.

And it’s important too to think beyond the devices we’ve traditionally networked. Installing a wireless router, setting up a WLAN and then logging in a laptop, a tablet, some phones and maybe a set-top box and a TV is one thing; hooking up a host of appliances and sensors, all forming part of what’s called the Internet of Things, and it’s another matter altogether. Techies like us might welcome the challenge of putting all this in place, but most folk will simply want to plug it in and have it work. IEEE 1905.1, if it works as well as its proponents claim, will be the technology that makes possible extending home networks from a handful of devices to dozens of them. ®