Fwd: Re: I-D ACTION:draft-bvenkat-chips-on-avians-00.txt

Rohit Khare (rohit@uci.edu)
Fri, 10 Dec 1999 00:14:43 -0800


Date: Thu, 9 Dec 1999 14:19:06 -0600 (CST)
From: "Robert G. Ferrell" <root@rgfsparc.cr.usgs.gov>
Subject: Re: I-D ACTION:draft-bvenkat-chips-on-avians-00.txt

>The connection topology can be non point-to-point for each carrier
>and as specified in RFC 1149 [1] can be used without significant
>interference with one another, outside of early spring.

Carrier species and circannual timing will be critical issues here.
For example, while members of the columbiformes traditionally employed in
RFC 1149-type ASCII message vectoring might experience little if any routing
variation throughout the year, an unfortunate selection of, say, _Sterna
paradisaea_ in either late winter or early fall might result in an
unacceptable
latency period due to suboptimal routing. A standard avian carrier needs
to be developed, perhaps by genetic engineering, which will have minimal
reactions to seasonal variations in the local diurnal cycle.

>The bio-medically engineered chip allows low frequency signals
>to be transmitted by these specially equipped avians that helps
>signals move around large objects such as skyscrapers

Extensive experience in the field as a graduate student led me to the
conclusion
that this collison avoidance mechanism was highly unreliable during periods
of inclement weather, most notably thunderstorms. Avian/fixed structure
contact, particularly when such structures exhibited large expanses of
transparent/translucent glass, were common and almost invariably resulted in
loss of the carrier and thus of the transported data. Any probability of
success index should take into account the weather conditions at the time of
transmission and the architectural topology of the anticipated route.

>In addition the chip also allows for high frequency signals to be transmitted
>that are inaudible to the human ear.

Care must be taken that the signals are not inadvertently made
audible en route,
lest the carrier attract extraneous and detrimental predator attention.

>IP traffic funnelled through after such negotiation can be
>connection oriented as in TCP or unreliable transport as in UDP.

Connection oriented traffic is inadvisable, due to the latency of
transmission. The carrier might wander away or be distracted during signal
exchange, with an attendant loss of data integrity.

>The issues to be discussed include addressing for each such
>avian prior to the negotiation, after the negotiation and for
>each low altitude IP tower

It should be noted that these towers must be constructed of a material that is
highly resistant to the corrosive effects of uric acid deposits, a significant
by-product of carrier physiology.

>The low delay is achieved by the high data content in the fast
>moving tweets and chirps, the variations of which are unheard of
>in the human hearable frequencies. Thus these tweets and chirps
>may be unheard by the normal human ear except for the upper range
>of lower frequency chirps that provide for high delay and low
>throughput for traffic of the kind that requires delivery but not
>instant delivery.

One factor to consider here is that a great many of the most suitable carrier
species produce highly stylized but imperfectly predictable signals
that must be
filtered or suppressed in order to achieve an acceptable signal-to-noise ratio,
given that message transmission is acoustically achieved. One might obviate
this by use of carriers with limited signal production in the
frequency range in
question, such as some members of the pelecaniformes or struthioniformes, but
substitution of these species introduces a entirely different set of challenges
(in the latter case, for example, lack of aerial locomotion is problematic).

>The layer 2 addressing is done by allocating a MAC address to
>every chip that is set on board an avian's brain. Appropriate
>surgical techniques may be used to implant the chip with
>connections to its auditory and vocal mechanisms.

Since research has shown that many of the more desirable messaging carrier
species possess small quantities of magnetite in their cranial cavities, the
possible deleterious interactions of this material with the implant must be
explored more fully before the reliability of either data integrity or signal
routing can reasonably be assured.

>For this reason the avians are tagged to be released in areas exclusive of the
>other's if they happen to have the same send/receive frequency.

A certain cross-channeling effect is inevitable, given that routing cannot be
controlled once the carrier has left the station of origin. Given this fact,
one must be prepared to accept that collisions will occur (see also my comments
on structure avoidance, above).

>Such collisions would require drastic action such as
>shooting down the colliding avian that has contravened its
>avian arena boundaries.

In certain circumstances this would decrease the effective end-to-end bandwidth
to the point that sneaker net might be a more effective means of communication.

>It is an intrinsic advantage of this design that the MAC
>address (the prefix at least) can be learnt from the
>frequency of the avian chip. The OUI portion of the MAC
>address can be shorter than the standard 24 bits.

Of course, the potential for unique identifier increases geometrically if one
considers that each avian carrier possesses a unique roughly 30 bit DNA
sequence.

>Avian arena changes can be negotiated through the mobility
>of an avian into another avian's arena. Thus two avians on
>the same frequency may arrange to swap one another or
>arrange to rearrange the distribution of same frequency
>avians through a protocol. This subject too is left for
>further enquiry.

Uncontrolled avian-to-avian interactions of this type tend to be sufficiently
traumatic to one or both of the carriers that data integrity would most likely
be compromised in such situations.

>A single chipped avian serves as a repeater.

I would suggest the Chipping Sparrow (_Spizella passerina_) as an excellent
candidate for this position.

>With regard to the degradation of
>its chirp and tweet beak and vocal cords, transmission of frames
>may be found to be degrading thus leading the avian to be put to
>its terminal end of service by removing the chip from its brain.

Packet, not to mention carrier, capture is problematic as the carrier
approaches
its TTL value. A frequency of use and reliability of transmission expectation
that varies inversely with carrier age is advisable.

>If a collision occurs then both avian carriers back
>off as per the CSMA/CD mechanism outlined in IEEE 802.3 standards.

Only if the carriers are being closely monitored and physically modulated by a
human agent with collision avoidance and detection rules well in mind. When
collisions occur among avian carriers, the general rule of thumb is
to expect at
a minimum a considerable increase in latency and in worse cases a complete loss
of data and carrier.

>Chip manufacturers provide appropriate interfaces to tap into a dead
>avian or a
>live one to transfer data back and forth from an avian chip to the
>said device which may be a router, that is tangibly visible as one
>to humans.

I might add that, while they do not exhibit favorable transmission
characteristics for any messaging other than campus-wide (and even then usually
line-of-sight, with a strong throwing arm), dead avians are remarkably
predictable in their behavior and are less apt to be lost due to routing
anomalies.

>The loss of a carrier in an arena can result in the stoppage of
>traffic in that arena onto the adjacent one. This is taken care by
>providing a backup avian carrier since avians usually travel in pairs.

This is highly species-specific. Fault tolerance that relies on this principle
narrows the field of prospective carrier species to those which form strong
pair-bonds, and further renders reliable signal transmission outside of the
breeding season an iffy proposition at best.

>As discussed earlier security is not a problem except in the
>cross avian arena border transition case, which might take place
>if an avian finds a courtship to be undertaken with another
>avian in a different avian domain. This is sought to be
>restricted by injecting suitable mitigating agents that
>suppress the enzymes responsible for such courtship in a given
>avian carrier.

Those same 'enzymes' (actually hormones) are also responsible for
vocalizations.
Suppressing them would render the payload inaccessible, at least until the
suppressive effect subsided. This would introduce considerable latency, and
repeated or improperly conducted suppressions might reduce the TTL of the
carrier significantly.

RGF

Robert G. Ferrell
Internet Technologist (with otherwise useless MS in Avian Ecology and
Systematics)
National Business Center, US DoI
Robert_G_Ferrell@nbc.gov