Follow Slashdot stories on Twitter

 



Forgot your password?
typodupeerror

Comment: Line of Sight (Score 1) 55

The problem with radio transmissions in the EHF band is that they are incredibly line of sight (LOS) restricted. Any structures or vegetation between the client and access point will block the transmission. It is also highly susceptible to rain fade. And while 73 GHz is above the atmospheric oxygen attenuation death zone (57–64 GHz), it is still highly affected by atmospheric absorption. Range for a point-to-point (PtP) system is a kilometer or two at most with sane ERP levels.

There are already a couple of manufacturers who make PtP wireless network devices for the 60–80 GHz band, but they're mainly used for short distance backhaul networks. They're less expensive substitutes for running fiber between buildings or across a campus. The idea is that you have your PtP backhaul running at 10, 24 or 60–80 GHz and then you communicate with your clients using a PtMP network in the UHF band using WiFi, WiMax or LTE.

Comment: Re:Waste is heat! (Score 1) 198

Those systems require a significant amount of labor and materials for the excavation and ducting. They also have a limited cooling and heating capacity due to their passive nature. It is usually advantageous to install an active system, such as a heat pump with a geothermal loop.

Comment: Re:Waste is heat! (Score 3, Insightful) 198

That's fine when you live in an Arctic wasteland, but a good portion of the world population lives in an area where the climate requires active cooling during the summer months. So that waste heat must either be removed using fans or air conditioning, which costs money.

When I lived in a cool city, my Core i7 930 and my wife's Phenom X4 955 were fine. But when I moved to a city where summer temps can exceed 40C, I replaced them with low power (S series) Haswell systems. My July electric bill went down 10% from the previous year. After selling the old equipment, the upgrades will pay for themselves in under 2 years.

Comment: Re:Just disable it... (Score 4, Insightful) 198

One problem with modern electronics is when the manufacturer figures that you're always going to put your device to sleep instead of fully powering it down, so they don't put much effort into optimizing the boot time from a cold power up.

Take for example desktop PCs. There are some motherboards where the firmware initialization is around two seconds. But I've seen it as high as fifteen seconds for a desktop motherboard and over a minute for a server motherboard, even when you have all of the options set to allow the fastest boot possible. That is a very wide difference from one motherboard to another.

When I read motherboard reviews, very rarely is boot time ever mentioned. So is this a chicken-vs-egg scenario where users don't care about cold boot times because they're happy with standby and hibernate modes? Or do users care, but it is so rarely reported that we always end up with motherboards that drive us to standby and hibernation modes?

Comment: Re:This is interesting.... (Score 2) 573

by toejam13 (#49310563) Attached to: Greenpeace Co-Founder Declares Himself a Climate Change Skeptic

Ocean acidification and upper atmosphere particulate pollution are anything but localized. The former is leading to widespread worldwide disruption of the seafood industry, the latter is leading to widespread drought conditions.

Most of the rest are regional at the least, with pollution traveling possibly thousands of kilometers. As example, air pollution from China is being detected in increasing levels along the North American west coast. Heavy metals dumped in streams in Montana can be detected in Mississippi and Manitoba.

The only one in that list that is localized is groundwater contamination. Even then, look at the radioactive creep in the groundwater under the Hanford Site in Washington. It is slowly creeping towards the Columbia River, and is expected to start seeping out within a few decades. The contamination rate will be minimal, but that water is used for both crop irrigation and drinking water.

You have a much better point with your second remark. Rising ocean levels and changing climate will be heavily disruptive. It'll also be slower to happen. China and India are poisoning their agricultural breadbaskets right now. Same with mega-droughts. Good chance that we're going to see widespread famine in Asia within a couple decades unless they radically change their agri-policy.

Comment: Re:This is interesting.... (Score 4, Interesting) 573

by toejam13 (#49310293) Attached to: Greenpeace Co-Founder Declares Himself a Climate Change Skeptic

You've hit on one of the main issues with Global Warming. How much of it is a man made issue and how much of it is due to natural causes? There are a few reports that suggest that the ice caps on Mars are slowly receding too, so it may be in part due to changing solar activity. I see the next battle being exactly how much human activities are to blame.

Having said that, the debate over Global Warming is distracting in how it steers the conversation away from all of the other problems man-made pollution are causing. CO2 emissions appear to be the main factor in ocean acidification. Particulate pollution is a main factor in changing evaporation rates, rainfall frequency and lung disease. Nitrogen oxides contribute to acid rain. Heavy metals and radioactive metals from coal have a number of adverse health effects. Improper fracking installations can contaminate ground water. Tailing ponds can leak and contaminate surface water.

All of this seems to have taken a back seat. To be honest, I wonder if energy companies are quietly happy about this. Global Warming has so many shades of gray that it is easy for energy interests to dismiss it and for people to believe them. Traditional pollution is a lot more black and white, making it hard to wave away as quack science. Changing the conversation is a fantastic way to stop talking about it.

Because if we were talking about how 40-year old coal and oil fired power plants skirt modern pollution controls by doing upgrades under the guise of "repairs", allowing them to keep their grandfathered pollution limits, I think people would be really pissed. What's the point of companies like GE and Hitachi advertising their modern cleaner power plants during the nightly news when nobody is forced to buy them? If that was the center of topic, there would be a better chance of it changing.

Comment: Artists often get little (Score 3, Interesting) 157

by toejam13 (#48977687) Attached to: Major Record Labels Keep 73% of Spotify Payouts

Music artists have often received little from broadcasting. Historically, they've received the bulk of their money from live performances and merchandise. Most of that broadcast money goes to the studios, the producers, the managers, the studio, the songwriter, agents and lawyers. Singers (if they're not also songwriters) usually come dead last.
My understanding is that many new artists have come to realize this scam and are starting to avoid the major labels, using alternate channels of distribution instead. It may not sell as much music, but they get a much larger slice of the pie

Comment: Re:Physics doesn't work like that. (Score 1) 54

by toejam13 (#48881581) Attached to: TWEETHER Project Promises 10Gbps MmW 92-95GHz Based Wireless Broadband

The higher the frequency, the less penetration of solid objects you have.

At -that- frequency, it'll work well for extremely short range, indoor, communications. But as soon as you put something even slightly solid, or damp, in the way, the signal will get blocked.

Yup. At this frequency, walls and vegetation are essentially opaque to RF. This will be useful for in-room or sub-kilometer line-of-sight deployments. Great for Phoenix (little rain, few tall trees), horrible for Seattle (damp, heavily forested).

One good thing about hitting 25 GHz or higher is that indoor APs and outdoor APs don't fight with each other the way that they do at 2.4 or 5.8 GHz (lower co-channel interference). So you can have a PTMP or mesh network running in dense areas like New York City. But with the range limitations, it'll need to be a dense network in order to get any sort of coverage. Your hop count is likely to skyrocket if you're using a mesh. High speed, horrible latency.

Comment: Even in China and India, English will dominate (Score 1) 578

by toejam13 (#48723527) Attached to: What Language Will the World Speak In 2115?

In many eastern nations, English is so widely used because it is seen as a neutral language. Many people in southern China who speak Yue Chinese (ie, Cantonese) dislike speaking Mandarin, which is a mutually intelligible language. Likewise in India where there are 7 major language groups comprising over 120 languages and over 1000 dialects and minor languages, many Indians (especially of the upper caste) prefer to use English as opposed to a non-local language. In these cases, English will thrive if only as a dominant second language.

India comes up again for another reason, which is the British Commonwealth. English is widely spoken in these member countries, which comprises a good chunk of the population in Africa and Asia.

Comment: Re:voicemail to email (Score 1) 237

by toejam13 (#48662859) Attached to: The Slow Death of Voice Mail

Voicemail to text is probably the best evolution of voicemail. Speech to text has gotten very good, so there is no reason that we can't have the system perform a S2T on a message, then sending that message as a text. Keep the original recording around in case the translation is wrong, but delete it once the text has been deleted.

e-credibility: the non-guaranteeable likelihood that the electronic data you're seeing is genuine rather than somebody's made-up crap. - Karl Lehenbauer

Working...