A brief introduction to the WiGig version 1.0 specification from WiGig's site:
> Supports data transmission rates up to 7 Gbps ? more than 10x faster than the highest 802.11n rate
> Supplements and extends the 802.11 Medium Access Control (MAC) layer and is backward compatible with the IEEE 802.11 standard
> Physical layer enables both the low power and the high performance WiGig devices, guaranteeing interoperability and communication at gigabit rates
> Protocol adaptation layers are being developed to support specific system interfaces including data buses for PC peripherals and display interfaces for HDTVs, monitors and projectors
> Support for beamforming, enabling robust communication at distances beyond 10 meters
> Widely used advanced security and power management for WiGig devices
I dont actually see how a 60GHz specification can be backwrds compatible with the existing 802.11 specification simply due to the different operating frequencies.?
I accept they may use similar methods etc but imagine the drop in throughput when an 802..1g client wanders in.
Again maybe I am missing something.
They might just be meaning that some of the channel access mechanisms etc are based on 802.11 mechanisms and/or that the AP's might be able to "switch" from 60 Ghz mode back to 2.4 Ghz mode to "act as a regular old AP" [ say in areas where you wanted more range ]. Only hypothesizing.
If anyone has "techie stuff" on all this, pse post so we can devour it.
Checkout ?802.11ad New Technique Proposal? on Google. Sony is proposing an interesting technique for existing .11 systems to ?aid a brother out? in terms of beacon data.
Found a contact number for someone who contributes to the .11ad group and called him up. He was very helpful and told me that there are actually going to be formal discussions soon on the actual definitions of ?backwards compatibility?. The items mentioned previously will be included.
Will be sending off an e-mail to him when I get time asking for some more info. Will keep everyone posted.
Bye the way, if anyone has any questions they would like me to onpass to the IEEE folks, please let me know by the end of the week. I'm planning on sending the mail off on Saturday.
Just got off the phone with the folks from the Wireless Gigabit Alliance. They told me that they have not published any whitepapers etc at present, but would be putting some out in the future.
If someone is a member of a company, they can apply for membership and get a copy of the spec.
Anyone ?....Anyone ?.......Beuller ?
Curious about the effect WiGig devices will have on human body. How about the radiation? 60 GHz belongs to EHF after all...
I think thats much more to do with output power aswell as frequency,
We can assume its pretty low power but no doubt it will raise the usual questions.
I had an implementation once where the clients were complaining of headaches after the wireless went in, obviously blaming the wireless. It was the teachers in a school.
We asked them to record when they had headaches for a month as we hadnt gone live we had a trick up our sleeve,
The first two weeks wireless on = headaches.
The second two weeks wireless off = headaches.
Obviously we didnt tell the teachers the wireless was turned off, however we did manage to assertain there was no correlation between the headaches and the wireless.
Can RF harm you ? Absolutely. However there are multiple factors involved including frequency and power.
The thing that people should be concerned about is cell phone usage. I?m not talking about the occasional phone call during the day, I?m talking about people who are using their cell phones for several hours a day with the unit pressed against their head. There are obviously reports ?for? and ?against?, but it should always be remembered that you have an 800 MHz or 900 MHz [ only a smidgen away from 1 GHz, the ?formal start? of the microwave band ] signal from the transmitter jammed against the side of your head blasting right through your skull and eyes. I used to take a field strength meter and put it on the other side of someone?s head whilst they made a phone call. They were always shocked at the results to say the least. I have a healthy respect for RF. I?ve been around it my whole working life for over 25 years. From 80,000 watt tropo systems to microwave to satellite to wi-fi. There has been a court case going for years re the British Telecom engineers who drove around for 8 hours a day with a cell phone pressed against their heads, making test calls [ when mobiles first came out ]. Can?t remember the exact figures, but over 50% of them developed tumors. Again, it?s not the occasional call, it?s those who seem to have the phone permanently attached to their heads who should reconsider their usage. It?s pointless even mentioning this to most of them as the standard reply is usually ?I?m still here am I not ?? or ?That?s rubbish , I read a report that said they are safe as houses??. Good for you, it?s your body.
The tissues of the eyes are very sensitive to radiation of many different types.
Wi-Fi signal levels from an office AP don?t really concern me [ don?t have an antenna right beside your head though ]. The levels in use are very small. However, great caution should be taken around directional antennas of any sort, especially on bridging links.
Cwnpchina has raised an interesting point. We really don?t know much about the effects of 60 GHz on the body. It?s not all about power levels, frequency is important too.
I spent many years working on Intelsat Standard A satellite antennas. 105 feet in diameter and weighing over 300 tons. Similar to the ones shown below
The main reflector is made up of a series of panels which fit close together, but not completely [ to allow for thermal expansion etc ]. Riggers would constantly be working behind the panels cleaning them of rust etc as well as doing painting. Surprisingly often only a few watts of actual RF power would be sufficient to complete a satellite link. The enormous gain of the antenna would allow small amounts of physical power to be used in order to get a particular EIRP. The amount of power that leaked out between the panels through the gaps was calculated by the experts to be ?so small that it would barely matter?. A group of riggers whom I knew worked for over twenty years doing this and other work. Out of five of them, one lost an eye to eye cancer, another developed tumors in his eyes, another died from tumors in the head and the other two had various ailments. Anecdotal yes, but each was asked by specialists ? Have you been around RF radiation ? These tumors are consistent with that?.
I am very, very careful around RF.
Bye the way, if anyone talks with their head cocked to one side and the cell phone jammed in the gap, you might want to re-think that. The thoracic outlet comes out of the scalene muscles in the side of the neck. Once those muscles get tight and press against the nerves, numbness of the shoulder, neck or fingertips can and does occur. Some unfortunates lose all control of their hands and then their livelihood. Seen it many times. Sadly very few doctors are aware of this mechanism.
As a young paratrooper I was constantly aware of safety and it saved my life on more than one occasion. I have kept that high regard for safety standards to this day. Always be cautious.
I know RF can be dangerous and I guess its all about dosage, long term low level effects or very high short term seem to be harnfull.
I have heard of microwave engineers getting the buzz swinging across antenna fields as they dont always turn them off.
Wasnt aware our little yagis were the ones to watch though.