Thesis 63

The necessary wireless networking protocols already exist.

If IPv6 gives us a way to identify each of the almost unimaginably rich profusion of nodes everyware will bring into being, we still need to provide some channel by which those nodes can communicate with each other. We already have some fairly specific ideas of what such a channel should look like: Most of our visions of ubiquity presuppose a network that:

• is wireless;

• provides broadband;

• affords autodiscovery;

• is available wherever you might go.

As it happens, each of them is neatly answered by a brace of emerging (and in some cases conflicting) networking standards.

At ultra-short range, a new standard called Wireless USB is intended by its developers to succeed Bluetooth in the personal area networking (PAN) role during 2006-2007, connecting printers, cameras, game controllers, and other peripherals. Supported by the WiMedia Alliance, an industry coalition that counts HP, Intel, Microsoft, Nokia, Samsung, and Sony among its mainstays, Wireless USB islike similar ultrawide-band (UWB) protocolsa low-power specification affording connection speeds of up to 480 Mbps. Undeterred, the industry alliance responsible for Bluetooththe Bluetooth Special Interest Grouphas announced its own plans for a new, UWB-compatible generation of their own standard. (Confusingly enough, the group counts many of the same companies supporting Wireless USB among its adherents.)

As we've seen, this is sufficient to stream high-definition video between devices in real time. Given that such streams represent something like peak demand on PAN, at least for the foreseeable future, we're probably safe in regarding the challenges of wireless networking at short range as having been overcome upon the introduction of Wireless USB or similar.

Wireless USB and its competing standards, although intended mainly to link peripherals at ranges of a few meters, begin to blur into what has historically been considered the domain of local area networking, or LAN. They certainly offer higher speeds than the current widely-deployed wireless LAN implementation, Wi-Fi: While the 802.11g variant of Wi-Fi provides for a nominal maximum speed of 54 Mbps, in practice, throughput is often limited to a mere fraction of that number and in some cases is barely any faster than the 11 Mbps maximum of the earlier 802.11b standard.

Nor can current-generation Wi-Fi base stations cope with the longer ranges implied by so-called metropolitan area networking, in which regions anywhere up to several kilometers across are suffused with a continuous wash of connectivity. vulnerable on both the counts of speed and range, then, Wi-Fi will almost certainly be superseded over the next year or two by the new WiMAX standard.

WiMAX isn't some new and improved form of Wi-Fi; it is a relatively radical departure from the Ethernet model from which the 802.11 standard is originally derived. (Some of the blame for this common misperception must clearly be laid at the feet of those who chose to brand the standard thusly.) Fortunately, this does not prevent the standard from offering a certain degree of backward-compatibility with earlier devices, although they will surely not be able to take advantage of all that it has to offer.

And what WiMAX has to offer is impressive: bandwidth sufficient for simultaneous voice over IP, video, and Internet streams, with data rates of 70 Mbps provided over ranges up to a nominal 50 kilometers. The speed is only a little bit faster than the swiftest current flavor of Wi-Fi, 802.11g, but the range is vastly improved. When both WiMAX and Wireless USB have supplanted the current generation of networking standardsas they are supposed to, starting in 2006we will have three of the four elements we were looking for in our robust ubiquitous network: wireless broadband connectivity, at a range of scales, just about anywhere we might think to go.

This leaves us only the issue of autodiscovery.

One of the less charming provisions of Bluetooth, at least in its earlier incarnations, was that devices equipped with it did not automatically "discover" and recognize one another. They had to be manually paired, which, on the typical mobile phone, meant a tiresome descent through the phone's hierarchy of menus, in search of the one screen where such connectivity options could be toggled.

While establishing a Wi-Fi connection is not typically as onerous as this, it too presents the occasional complicationeven Apple's otherwise refined AirPort Extreme implementation of 802.11 confronts the user with a variety of notifications and dialog boxes relating to the current state of connection. When I'm out in the field, for example, my computer still asks me if I'd like to join one or another of the networks it detects, rather than making an educated guess as to the best option and acting on it.

And this is precisely the kind of overinvolvement that a classically Weiserian everyware would do away with; presumably, the task you are actually interested in accomplishing is several levels of abstraction removed from pairing two devices. That is, not only do you not want to be bothered with the granular details of helping devices discover one another, you're not particularly interested in connectivity per se, or even in sending files. These are simply things that must be accomplished before you can engage the task that you originally set out to do.

Autodiscovery, then, however arcane it may sound, is a sine qua non of truly ubiquitous connectivity. you shouldn't have to think about itnot if our notions of the encalming periphery are to make any sense at all.^[*]

^[*] We should note, however, that this is precisely the kind of situation the doctrine of "beautiful seams" was invented for. If the default setting is for users to be presented with fully automatic network discovery, they should still be offered the choice of a more granular level of control.

But while a smooth treatment of service discovery is indisputably critical to good user experience in ubiquitous computing, it's a question more of individual implementations of a wireless networking technology than of any given protocol itself.

With the near-term appearance of standards such as Wireless USB and WiMAX, the necessary provisions for ubiquitous networking are at last in hand. The question of how to connect devices can itself begin to disappear from consciousness, unless we explicitly desire otherwise.