Underwater communications is a challenge. Radio waves quickly attenuate and visible light doesn't penetrate very far. To get high speed robust communications at any depth you need to be tethered by a cable. Of course that is too limiting for many applications.
Acoustic waves can propagate for long distances and people have built acoustic modems for some time. These are challenging to design and have tended to be application specific. So it is interesting to see a commercial undersea modem modified to use an IP compatible protocol stack -- the Internet underwater... (pdf)
The Internet Underwater: An IP-compatible Protocol Stack
for Commercial Undersea Modems
Yifan Sun Department of Electrical Engineering
State University of New York at Buffalo
Department of Electrical Engineering
State University of New York at Buffalo
Recent underwater sensor network research has focused
on developing physical, medium access control, and network
layer protocols to enable high data rate, energy-efficient and
reliable acoustic communications. However, it is now essential to design and standardize architectures that will enhance
the usability and interoperability of underwater networks.
This paper proposes a networking architecture to efficiently provide interoperability with traditional TCP/IP protocol stacks for commercial underwater modems. The proposal is based on an adaptation layer located between the
data link layer and the network layer, such that the original TCP/IP network and transport layers are preserved un-altered to the maximum extent. The adaptation layer performs header compression and data fragmentation to guarantee energy efficiency. Furthermore, the proposed architecture includes mechanisms for auto-configuration based on
router proxies that can avoid human-in-the-loop and save energy when broadcast is needed. The proposed architectural
framework was implemented as a Linux device driver for a
commercial underwater network modem SM-75 by Teledyne
Benthos. Testing and simulation results illustrate that the architecture efficiently provides interoperability with TCP/IP.
Very short range/low bitrate communication harvesting ambient rf power from the University of Washington (pdf). Very early on and this version would be insecure, but it may be an interesting start to moving towards the Internet of things.
The key finder towards the end is a more interesting example than the card reader..
I've been weaning myself from the large search engines - particularly Google - along with services like FaceBook for about a year. I now mostly use DuckDuckGo for search - it isn't the best by a long shot, but I know how to form search questions and dislike the ads and being the product for a third party. I recognize that I am never really free of being sold as a project online, but I try to minimize it where possible.
Several mashups of a Pixar inspired parody of NSA appeared in the past day or so. Here is one of the better ones (yeah - I know YouTube was purchased by Google a long time ago. That is the Google service I am most connected to) ... spitting into the wind perhaps...
Most people who use desktop video conferencing don't pay any attention to audio or video quality. (I can't say I'm careful, but I know better). There are any number of things you can do for audio quality (a good podcasting microphone or better can be had for $100 or so), but video quality often comes down to lighting.
Here is a DIY on the cheap project using $26 worth of kit ...
There are a number of problems with this - it is over all service plans and includes home links to the end user computer (usually wifi), but Netflix believes this more or less averages out and the relative ranks are meaningful. I've seen several more detailed studies and the relative ranking isn't too much of a surprise.
Of course the rub is you can rarely get more than two providers in any region and sometimes it is one or even none ... But if you are thinking of switching ISPs it may make sense to see if there are big differences between those you have available.
This sort of testing should be encouraged and at a level where direct numerical realistic performance characteristics are measured. It would be a useful tool for competition. And, of course, it makes sense to do this internationally.
A correspondent notes that Netflix requires at least 2 megabits per second for standard definition movies to play without long pauses for buffering - so if your ISP is not better than that, the quality of your experience will suffer. It is embarrassing to see so many numbers this low.
I'm sure this will be met with comments suggesting Netflix isn't measuring properly, but let's have some transparency and have proper regular monthly measurements for all of the providers in all of their regions.
Perhaps this is the only way we get service improvements.
Mobile service in the US is handled by a small group of providers that are an effective oligopoly. They bundle services including voice, text messaging and a connection to the Internet (and a few others). These are marketed in bundles, the components of which do not necessarily directly relate to the cost of providing the service. Over time the components of the larger bundle are shifted around to reflect the current state of marketing.
Text messaging, by itself, is enormously profitable. But people value it and pay what seems like a huge amount of money given the amount of data exchanged (over $1,000 per megabyte in some cases), but the pricing is an artificial number and just one of the components of the bucket. It is possible to avoid most or all of your carrier's text messages by using Apple's iMessage service, WhatApp, or any of a number of free services that use the Internet connection of the phone for the link.
Some of these third party messaging apps are much more flexible than conventional text messaging and in some parts of the world are becoming common. As they become more common in the US, rest assured the carriers will readjust the bundles in their offered service plans to preserve their profits.
WhatsApp is interesting as it caught Firms like Facebook sleeping. Facebook didn't offer a competing service, while WhatsApp has grown to nearly a quarter of a billion mobile users in a few years - capturing users Facebook and others would have loved to have.
We'll be moving into more of a world where voice is carried over the Internet and the need for regular phone service will begin to fade. The carriers will make an adjustment for that too. It is too bad you can't buy individual services - just as it is too bad you can't unbundle your cable service. These marketing devices exist to protect some very high profits and, rest assured, if unbundling was forced, the component prices would be very high - largely due to nature of oligopoly. I'd be in favor of making carriers offer nothing but an Internet connection and a conventional dial tone service -- but to make that work you'd need real competiion and the bar for doing that is too expensive in infrastructure as well as in Congress. (although some work-arounds are emerging) Part of the problem is artifical $pectrum $carcity and there are ways around that with time and some change of thinking among the regulators. I'm not terribly optimistic.
In the meantime you can enjoy a bit of arbitrage and ditch your text messaging plan.