Thank you!!!

Nice to see your excitement about CCN!

Your post is an excellent interpretation of the benefits of the CCN architectural shift, as well as some (solvable) challenges like pushing additional state to the routers to temporary store data interests from users.

I had the chance this summer to talk with Van during the 4Ward summer school and attend the long tutorial on CCN:
http://www.comnets.uni-bremen.de/typo3site/uploads/media/vjCCN-FISS09.pdf

Van pointed out that the hardware requirements of routers where comparable to todays, in the simplest version of CCN
What I also understood from the off-line discussion on forwarding table sizes and the forwarding approach itself are two key aspects towards deployability, which is a key issue in any (future?) internet-working approach:
1) CCN can run over IP as an overlay, gradually deployable at edge routers
2) On one extreme, CCN could mimic the IP model by letting content names represnt host identifiers and providing e2e routing between hosts. (here is a plug to one brief related post of mine: http://chesteve.wordpress.com/2009/08/18/van-jacobson-content-centric-networking-insights-at-the-4ward-future-internet-summer-school/ )

IMO, both characteristics are fundamental for incentives for adoption and feasible transition strategies, or like Azer points out in the previous comment, for a (non-DNS-dependent) future with multiple parallel architectures.

Best,
Christian

> Then, it would really feel like we
> are chasing an evasive ghost

We are. That’s why the future may be for multiple co-existing architectures.

Cheers!

–Azer

En fin, me alegra que te haya ido tan bien y espero que sigas sumando éxitos para la bandera langreana.

Por cierto, qué coste tiene el análisis del genoma??

HOW SAFE ARE MICROWAVE AND SATELLITE ANTENNAS?

“Point-to-point microwave antennas transmit and receive microwave signals across relatively short distances (from a few tenths of a mile to 30 miles or more). These antennas are usually rectangular or circular in shape and are normally found mounted on a supporting tower, on rooftops, sides of buildings or on similar structures that provide clear and unobstructed line-of- sight paths between both ends of a transmission path or link. These antennas have a variety of uses such as transmitting voice and data messages and serving as links between broadcast or cable-TV studios and transmitting antennas.

The RF signals from these antennas travel in a directed beam from a transmitting antenna to a receiving antenna, and dispersion of microwave energy outside of the relatively narrow beam is minimal or insignificant. In addition, these antennas transmit using very low power levels, usually on the order of a few watts or less. Measurements have shown that ground-level power densities due to microwave directional antennas are normally a thousand times or more below recommended safety limits. Moreover, as an added margin of safety, microwave tower sites are normally inaccessible to the general public. Significant exposures from these antennas could only occur in the unlikely event that an individual were to stand directly in front of and very close to an antenna for a period of time.

Ground-based antennas used for satellite-earth communications typically are parabolic “dish” antennas, some as large as 10 to 30 meters in diameter, that are used to transmit (”uplinks”) or receive (”downlinks”) microwave signals to or from satellites in orbit around the earth. The satellites receive the signals beamed up to them and, in turn, retransmit the signals back down to an earthbound receiving station. These signals allow delivery of a variety of communications services, including long distance telephone service. Some satellite-earth station antennas are used only to receive RF signals (i.e., just like a rooftop television antenna used at a residence), and, since they do not transmit, RF exposure is not an issue.

Since satellite-earth station antennas are directed toward satellites above the earth, transmitted beams point skyward at various angles of inclination, depending on the particular satellite being used. Because of the longer distances involved, power levels used to transmit these signals are relatively large when compared, for example, to those used by the microwave point-to-point antennas discussed above. However, as with microwave antennas, the beams used for transmitting earth-to-satellite signals are concentrated and highly directional, similar to the beam from a flashlight. In addition, public access would normally be restricted at station sites where exposure levels could approach or exceed safe limits.

Although many satellite-earth stations are “fixed” sites, portable uplink antennas are also used, e.g., for electronic news gathering. These antennas can be deployed in various locations. Therefore, precautions may be necessary, such as temporarily restricting access in the vicinity of the antenna, to avoid exposure to the main transmitted beam. In general, however, it is unlikely that a transmitting earth station antenna would routinely expose members of the public to potentially harmful levels of microwaves.”

Como cada domingo me levanto un poco más tarde de lo que toca y me acerco al quiosco a buscar algo de compañia para el desayuno… Tenía ganas de conocer algo nuevo asi que he probado con “Público” y me he topado con tu entrevista.

Me picaba la curisosidad asi que cuando he conseguido que mi hermano pequeño desocupara el ordenador aun recordaba la dirección de tu blog… todo un acierto ponerla…

He disfrutado leyendolo.

Un saludo desde Barcelona

David
Estudiante ing.aeronautica

Me está encantando tu blog. Lo seguiré atentamente.