Whither Wireless?

Widespread Wi-Fi May Have a Significant Impact on Future Internet Radio Usage
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Widespread Wi-Fi May Have a Significant Impact on Future Internet Radio Usage

For the last few years the common wisdom has held that radio broadcasting would not feel the full impact of the Internet until broadband wireless connectivity was widespread, and dedicated appliances were cheaply available (the "boombox with a browser").

Only then would the portability and ubiquity of radio be seriously challenged by online services. This was generally interpreted to mean that the fate of radio rested on so-called "3G wireless" or third-generation cellular deployment, placing much of broadcasters' future in the unsympathetic hands of telecom providers.

There was a loophole in this scenario, however, that gave many forward-looking broadcasters some comfort: Most 3G service would likely be metered - i.e., charged per minute or fraction of connect time, or perhaps per MB of downloaded material. This argued against its use for random, long-term, radio-style listening. Therefore, broadcast radio would not be threatened (or enhanced, depending on your point of view) by 3G.

Rethinking 3G

Since then, the rosy forecasts of 3G deployment have gone the way of most telecom providers' balance sheets, and deployment plans have been scaled back. So the concern among broadcast forecasters should have abated even further, right? Well, not quite.

While 3G has waned, Wi-Fi has soared. The IEEE 802.11 series of wireless networking standards, as Wi-Fi is officially known, was intended to be used exclusively for personal and enterprise wireless local area networks. It has begun to enjoy the generally unforeseen application of a wide-area, public-service utility type system, however.

Wi-Fi "hot spots" are turning up in hotels, airports and coffee shops, and communities are establishing their own coverage, either by municipally funded operations or, more broadly, by individual contributions of cooperative hot-spots. Some towns are already completely covered throughout their city limits by Wi-Fi service.

While some interference has occurred, the spread-spectrum design of 802.11 mitigates much of this problem, and the addition of new spectrum also helps. Meanwhile, the independent hot-spot approach is giving way to a more federated style in which adjacent operators are organizing and coordinating their spectrum use for greater efficiency, reduced interference and therefore increased throughput. So Wi-Fi is morphing from a purely private, last-meter Ethernet replacement into a public, broadband wireless Internet access system.

Because Wi-Fi is generally not provided under metered conditions, it lends itself well to casual browsing and online media usage. Its broadband nature, its use of cheap, portable hardware and its high reliability also make it quite usable for this application. This implies that the Wi-Fi revolution may have substantial impact on Internet radio's growth. It therefore behooves broadcasters to learn as much as they can about the technology and its potential.

802.n(x) explained

What we call Wi-Fi today typically uses the IEEE 802.11b standard, which offers 11Mbps of symmetrical bidirectional bandwidth over unlicensed spread spectrum in the 2.4 GHz band.

Transmit power is limited to 30 mW, but with directional antennas and sufficient height, this can offer coverage extending to >100 feet at full bandwidth from a single Wi-Fi access point, or AP. The AP is an inexpensive (~$150) transceiver that acts as a wireless Ethernet router, and is typically connected to an Internet service provider's terminal equipment, such as a DSL or cable modem, usually via Ethernet on an RJ-45 cable. This allows direct sharing of the ISP connection among all the wireless terminals in the network, which includes any device equipped with a Wi-Fi card or integrated Wi-Fi transceiver, the wireless equivalent of a NIC, a network interface card. Multiple Wi-Fi access points can be interfaced via a router to further extend the range of a wireless network. This is the approach often used in enterprise environments, where a large building or campus operates on a single Wi-Fi network.

Note that the AP approach emulates the client/server Ethernet model, but Wi-Fi also supports a peer-to-peer approach, which it calls an ad-hoc network. In this case, a PC acts as the Wi-Fi transceiver and interface to an ISP via Internet-sharing software.

A more recent variant is 802.11a, which is similar to 802.11b but provides up to 54Mbps connectivity in the 5 GHz band. Fewer devices currently operate in this range than in the 2.4 GHz band, so throughput and operable range is more often optimal in 802.11a (at least for the time being). This networking speed becomes more interesting for digital video connectivity, but even 802.11b offers plenty of bandwidth for audio services. The 802.11g version includes agility between both 802.11a and b systems.

Meanwhile IEEE is developing other families of wireless networking systems under the 802 rubric. The 802.16 standard, called "Wider-Fi," will offer even higher bandwidths, while 802.20 would offer handoffs between hot spots, akin to a cellular phone networks.

802.11 assumes that networking sessions will occur within a single wireless network, implying its usage for fixed systems only. Nevertheless, a laptop can be moved around within a hotspot without losing connectivity, as many users currently do within their homes or offices. In contrast, 802.20 would allow truly mobile wireless networking.

Although Wi-Fi is riding high at present, it is not a total panacea. The current state of security in the system leaves much to be desired. More about this and other Wi-Fi issues in an upcoming column.

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