Saturday, February 21, 2004

On "The First Tactical Mile"

This is a very rambling, very early draft of a paper on the subject of the "first tactical mile". All too often we focus on the fixed infrastructure, with the belief that we'll get to the "edge" of the network "later". That's the wrong approach. Comments, as always, highly desirable....

The TELCO industry makes frequent mention of "the last mile". By the term "the last mile", they refer to the local loop that connects the residential or business customer to the TELCO's Central Office. Signals are sent on that local loop by an analog waveform in a frequency range selected to provide reasonable quality for audio (voice) data.

The rising demand to send digital data over these analog circuits caused significant research and development in modulator/demodulator technology to improve throughput by encoding and error detection [and correction?] techniques. Development of digital subscriber line (DSL) and asymmetric digital subscriber line (ADSL) technology further increased the throughput available over the local loop, while remaining within the limits prescribed by Shannon's Law.

While the some companies invested in improved service over the local loop, others invested research and development dollars in exploiting the other non-energy transmission wires already running to homes and businesses: coaxial cable. Cable television had long been envisioned as a platform from which many services could be launched. Video on demand was one of the first services identified, because content was already available, and consumers were familiar enough with the concept that a lengthy market penetration and consumer education campaign was not needed. Proprietary computer networks, such as Compuserve, Prodigy, and America Online were also viewed as candidate content providers. The proprietary networks ran, of course, headlong into the free market, open standards world of the Internet when commercial restrictions were lifted.
Let us pause for a moment, and reflect upon the producer/consumer relationship and the asymmetry inherent in that relationship. This reflection will allow us to explore the vocabulary we use and to decide if that vocabulary is appropriate for the capability we want in the future.
We use terms like "the last mile" in the telephone business because in the eye of the service provider, the telephone company, the view is from the network out. This view holds in the telephone business in spite of the fact that all of the content in the telephone network is provided by customers at the edges of the network. From a content provider and resource consumer viewpoint, a better term would be "the first mile".

Telephone conversations are bursty -- discontinuous periods of speech, interspersed with periods of silence. Telephone conversations are also relatively short and infrequent. Traffic models did a reasonably good job of predicting network load except under infrequent incidents such as holidays and disasters. Adding data traffic to the telephone system introduced traffic with greatly different characteristics. Calls were much longer, more frequent, and less bursty.

The client-server model of the World Wide Web maintains the producer-consumer relationship found in television. The consumer either passively selects programming, in the case of broadcast television or so-called Internet radio, or sends a small request to a server to select specific content. The communication is asymmetric: small uplink requests followed by large downlink responses. The peer-to-peer interaction model has a different traffic pattern. Unless valuable content is non-homogeneously distributed, communication will be more symmetric, as peers alternate between acting as clients and servers in distributing content within the network.

Gamers have peer relationship -- asymmetry causes them problems. Music and movie file sharers do, as well. People that want to serve web pages from their homes run into dynamic IP address and NAT problems, as well as asymmetry challenges.

We prefer to think of tactical users not as being at the end of the "last tactical mile" or as being "disadvantaged users", but as being uniquely equipped users standing at the beginning of "the first tactical mile".

[the network is not armed. Users have the best local data, as a rule, and local data is usually the most relevant. Must beware of chauvenism on both sides of the argument. Very difficult to make the argument that the only part of the network that is armed is "disadvantaged".]

One could fairly claim that a change in terminology from "last" to "first" is intended to give the impression of progress through generation of new jargon, or a cute attention-getting novelty, but such claims would miss the mark. Precision in language -- selecting vocabularies suitable for the task at hand, and relentless enforcement of the use of these vocabularies is essential in an enterprise whose outcome is as serious as defense. the same individuals who would be horrified if their physician referred to "thingys" or "whatchamacallits" when discussing critical components or biological functions, think nothing of abusing technical vocabularies. Words such as "software", "hardware", and "platform" are among the most abused. This slang leads to confusion and misunderstanding.

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