Unfortunately, the 802.11 Frequency Hopping standard does not allow the device to learn which parts of the frequency range are interfered with. It would be nice, but it just can't happen, as it would screw up so many other parts of the standard.
Most countries in the world limit the 2.4GHz band - although it is unlicensed - by power output. The US gets 1 Watt max, UK and Europe get 0.1 Watts (France keeps changing its regs) and the Middle East still hasn't fully complied:)
3 Com are currently running a deal (in the UK, anyway - probably is similar in US) for 2Mbit/s Access Point and 3 ISA or PCMCIA cards for £800. Translate to US - translate to $ (usually works that way!) means a happy home WLAN for $800. Their kit is rebadged Symbol FH gear
I have run Quake 2 over an 11Mbit DS Aironet WLAN with 4 players and it was as good as my ethernet, even though one of the guys was a couple of km away (directional antenna for him)
If you are grabbing vast database files then it won't be happy, but it copes with most home user stuff:)
Actually, the DS receiver design is pretty good - DS uses a large chipping algorithm which effectively smears the signal from a high, narrow-band to a low, wide-band. A receiver using the wrong chipping algorithm just further smears the signal, but one on the same algorithm rebuilds the signal back to a peak and flattens all noise/extraneous signals - as best it can. What seems to be happening is that the FH transmissions are just far too high a noise level for the DS receiver to cope with!
In the UK the signal strengths are so low (100mW) that this is very localised - adjacent buildings act as individual cells, but the US has more of a problem as they are allowed 1W output power. Don't fry your brain cells, guys!
I install 802.11 networks by Symbol, Lucent and Telxon (Aironet/Cisco) and this is something I come into contact with more and more. Frequency Hopping (FH) devices tend to kill the reception by Direct Sequence (DS) devices, mainly due to the differences in signal strength. Multiple DS networks can happily coexist, and run at 1,2,5,11 or 25 MBit/s while keeping the actual signal at below ambient noise strength (nice - security-wise) FH networks just tend to upset all other 802.11 networks, and they only go up to 2 Mbit/s at the moment. The reason people use them is that they are very stable and solid. They just work, without tweaking!
With todays bandwidth demands, you have to go for the 25 Mbit/s gear (which gives you throughput roughly equivalent to a 40Mbit/s ethernet type protocol - due to use of CSMA/CA not CSMA/CD) so things should get better as more people use DS not FH:)
It may be that I'm just reading too much into it, but I don't really think that the Soviet Union crumbled because it was based on an unjust system. If that is the level this guy thinks on, then obviously he's going to come up with screwy concepts regarding anonymity.
Do you think he would like to give me all his personal details, credit card numbers, license etc? You know, just so he ain't anonymous:)
The S/390 is a superb, multi-user, highly secure stable machine; very scalable and powerful. Linux is very popular and getting ever more so with Microsoft's security faux pas; it is fairly stable, and fairly secure so people are turning to it in droves for database/app serve/web serve type uses.
Put the two together and you get a powerful machine, which is no longer esoteric and scary. It becomes more 'everyday' and easily accepted. Okay, this will lower the average salaries of an S/390 tech, but it will open up the S/390 to companies who wouldn't have thought of it before.
Oh, and sources at IBM say Red Hat is working on it.
In a warehouse or other typical wireless environment use voice over IP over RF (with html client built into the phone) and when roaming use GSM. Many of my customers have swapped wholesale from 150 or 200 mobile phones to IP phones for use in warehouses where Orange/Cellnet etc do not have a signal.
Still - Cisco's new box is pretty cool. And you don't have to use the proprietary extensions - so it can be kept fully compatible with those you may already have installed.
There are some interesting points here - I agree that the Motif/Iris/4dWM on Silicon Graphics machines is the best/smoothest/fastest/most intuitive GUI I have ever used, and I would love to see it transferred lock stock and barrel to Linux (which may happen with SG Linux, who knows) but is its smoothness just down to the power of the SGI box?? Does it need serious power to run the threads needed? I guess todays P3's should be better than the 8 year old SGI Personal Irises I have in my server farm at home, and they can handle hundreds of real time X Clients on my desktop machines. I think it maybe just takes getting together a good standard (and 4dWM is a good'un) and coding this stuff. Come on SGI - give us 4dWM for Linux!
We thought it was weird, but it wouldn't run on most of my colleagues machines anyway - so I opened it using a text editor, and it's written in plain, unobfuscated text. Lines like spread(email) are kinda obvious.
Still, the first guy who got it was distraught that she didn't love him after all:)
Umm - didn't Cray have terabyte+ RAM boxes masquerading as RAIDed disk? It's a speed thing. If you assume RAM is faster than disk (usually!) then running as much within RAM and not having to swap to/from disk is a GOOD THING (TM)
There is this trend to over-hype any news of IT mergers/buyouts etc especially when the word Linux comes up. Okay, this is probably going to get more readers with the current upswing in public favour for Open Source, but dramatising does nobody any favours. I'm quite happy to believe CmdrTaco et al when they say they have a cast iron contract which ensures Slashdot's individuality. Yes, even companies after money can act ethically. Anyway, why alienate the very population they want as a market??
VPN's are good - easy to access from anywhere, not just WLAN. But if you go for one Access Point inside the firewall, it is easy to set up both ends - the AP has access control lists and both the AP and radio NIC have to have a radio ESS ID programmed. Devices will only talk to others on the same ESS network. Then add the fact that the hop set and hop sequence (for frequency hopping) or the chipping code (for direct sequence) make for some fairly unique numbers it does tie things down pretty well.
11 Mb/sec ethernet bridges from Symbol and Telxon come in around £800 (or $800 in the states) and are basically plug'n'play (although you can configure the clever snmp gubbins if you want through telnet or html)
Afraid not! Symbol and Telxon have worked with some tweaking in some major food stores, but their abilities have to be limited and seamless roaming isn't exactly that.
Different countries hardware is NOT compatible. The US has "fry your brain" signal levels. Europe has 4 different frequency band standards (and France which is a law unto itself.) The base hardware works, but you need to replace the radio card in all cases!!!
Nope - if you go with direct sequence (eg aironet) you can't even see the signal above ambient rf noise. If you can see it you still need the chipping code (up to 63 bits) before you can reconstruct the signal and then you can run 3 levels of encryption over that (as default).
Hack that?? I think not! Why do you think the army developed it?
Seriously - go check out Empeg. It is exactly what you need. Linux device the size of a car stereo with up to 490 minutes of mp3 songs. Blue display - has plugins like geiss for winamp - matches my Golf GTI turbo dashboard.
I use Symbol and Telxon/Aironet 802.11 radio systems every day because they definitely have the top performance on the market. My department has tested every name on the market and they came out on top. Access Points configurable through telnet. Unfortunately they are only now porting drivers to Linux I tend to use it a lot for Quake 2 sessions - one access point for 5 users within a couple of hundred feet and a wireless ethernet bridge across about 5 km to 2 users in another suburb. No glitches! Runs sweet as sugar. The low overhead on an RF Lan means an 11Mbit link is generally 2 or 3 times faster than 10BaseT ethernet. And the price...well, if we did without, we would have to pay for dialup - 7 x 10p per minute x hours and hours - and get a performance hit.
On another note, have you seen Symbol's new palm pilot with laser scanner and rf connectivity. It can run as a telnet, 5250, oracle or html client. Nice.
Well I consider myself a lifelong geek with 23 years pulling things to bits/tinkering/hacking etc and it took me days to get X to work on my laptop. It's fine on my desktop machines, 'cos they're all pretty standard, but my laptop is an annoying version of IBM's Thinkpad - and on that topic, Linux token-ring card drivers...flaky!!
I can't understand why people have a problem with "tampering with nature." Until we became farmers and altered our environment we were no better than all other animals. We have changed foods by breeding, and now when we can do it quickly through gene splicing people yell "Blasphemy!" The logical step is to alter ourselves and our offspring. We subconsciously alter our potential offspring anyway by picking a partner who fits our ideal - this puts a huge bias on possible gene patterns in the child.
If we can remove all genetically transmitted diseases then we should, obviously. I don't think all future parents will want "perfect" offspring though. Even if we get that level of control over genes we will still want individuality for them.
Okay, so it is kind of a stand in for evolution, but we've lost a lot of the benefits of Darwinian selection anyway with the high levels of medical skill keeping alive those who in a wilder world would have died.
I say create a million versions of humans so we can survive everywhere - underwater, Mars, Venus, in poisonous atmospheres - or else we get too close to extinction from 1 event.
I don't agree that it's 'cos of old software, as I use modern software (lots of NT, Irix, Linux etc etc) and still prefer the older real keyboards.
I do, however, agree that it is subjective - maybe there should be keyboard for each type of user...someone like me has no need for Caps Lock, Windows key, SysRq etc, but maybe some people do. I would like a bigger spacebar and left shift, the pipe character up top right where it should be and a whole host of other things - but that would also cause disturbance to those who like it like that.
So, manufacturers - how about more of you doing a pfuca
No way - there has never been a desktop more intuitive to use than Iris Desktop. GNOME and KDE are like kid's toys in comparison! I use everything from Windows - blerrk - and Linux to Solaris and Irix and nothing has the fully integrated and organised feel of Iris/4Dwm. Everything just does what you want - no faffing about with apps; it just works Don't get me wrong, I am the biggest force pushing for Linux throughout my company and I love it - it will get there, but just not yet.
Slashdot Mirror
Unfortunately, the 802.11 Frequency Hopping standard does not allow the device to learn which parts of the frequency range are interfered with. It would be nice, but it just can't happen, as it would screw up so many other parts of the standard.
Sorry to disappoint
Frog51
Frog51
Most countries in the world limit the 2.4GHz band - although it is unlicensed - by power output. The US gets 1 Watt max, UK and Europe get 0.1 Watts (France keeps changing its regs) and the Middle East still hasn't fully complied:)
Frog51
Frog51
3 Com are currently running a deal (in the UK, anyway - probably is similar in US) for 2Mbit/s Access Point and 3 ISA or PCMCIA cards for £800. Translate to US - translate to $ (usually works that way!) means a happy home WLAN for $800. Their kit is rebadged Symbol FH gear
I have run Quake 2 over an 11Mbit DS Aironet WLAN with 4 players and it was as good as my ethernet, even though one of the guys was a couple of km away (directional antenna for him)
If you are grabbing vast database files then it won't be happy, but it copes with most home user stuff:)
Frog51
Frog51
Actually, the DS receiver design is pretty good - DS uses a large chipping algorithm which effectively smears the signal from a high, narrow-band to a low, wide-band. A receiver using the wrong chipping algorithm just further smears the signal, but one on the same algorithm rebuilds the signal back to a peak and flattens all noise/extraneous signals - as best it can.
What seems to be happening is that the FH transmissions are just far too high a noise level for the DS receiver to cope with!
In the UK the signal strengths are so low (100mW) that this is very localised - adjacent buildings act as individual cells, but the US has more of a problem as they are allowed 1W output power.
Don't fry your brain cells, guys!
Frog51
Frog51
I install 802.11 networks by Symbol, Lucent and Telxon (Aironet/Cisco) and this is something I come into contact with more and more.
Frequency Hopping (FH) devices tend to kill the reception by Direct Sequence (DS) devices, mainly due to the differences in signal strength. Multiple DS networks can happily coexist, and run at 1,2,5,11 or 25 MBit/s while keeping the actual signal at below ambient noise strength (nice - security-wise)
FH networks just tend to upset all other 802.11 networks, and they only go up to 2 Mbit/s at the moment. The reason people use them is that they are very stable and solid. They just work, without tweaking!
With todays bandwidth demands, you have to go for the 25 Mbit/s gear (which gives you throughput roughly equivalent to a 40Mbit/s ethernet type protocol - due to use of CSMA/CA not CSMA/CD) so things should get better as more people use DS not FH:)
Frog51
Frog51
Well go for it then.
RedHat 6.x is beautifully stable on the VAIO, and Q2 runs like a peach.
Frog51
It may be that I'm just reading too much into it, but I don't really think that the Soviet Union crumbled because it was based on an unjust system.
If that is the level this guy thinks on, then obviously he's going to come up with screwy concepts regarding anonymity.
Do you think he would like to give me all his personal details, credit card numbers, license etc? You know, just so he ain't anonymous:)
Madness, I tell you, madness.
yup - www.symbol.com
The main points here are:
The S/390 is a superb, multi-user, highly secure stable machine; very scalable and powerful.
Linux is very popular and getting ever more so with Microsoft's security faux pas; it is fairly stable, and fairly secure so people are turning to it in droves for database/app serve/web serve type uses.
Put the two together and you get a powerful machine, which is no longer esoteric and scary. It becomes more 'everyday' and easily accepted. Okay, this will lower the average salaries of an S/390 tech, but it will open up the S/390 to companies who wouldn't have thought of it before.
Oh, and sources at IBM say Red Hat is working on it.
The Parking Lot Is Full
In fact what I've been doing is much more fun:
Mobile phones with dual connection - IP or GSM!
In a warehouse or other typical wireless environment use voice over IP over RF (with html client built into the phone) and when roaming use GSM.
Many of my customers have swapped wholesale from 150 or 200 mobile phones to IP phones for use in warehouses where Orange/Cellnet etc do not have a signal.
Still - Cisco's new box is pretty cool. And you don't have to use the proprietary extensions - so it can be kept fully compatible with those you may already have installed.
There are some interesting points here - I agree that the Motif/Iris/4dWM on Silicon Graphics machines is the best/smoothest/fastest/most intuitive GUI I have ever used, and I would love to see it transferred lock stock and barrel to Linux (which may happen with SG Linux, who knows) but is its smoothness just down to the power of the SGI box?? Does it need serious power to run the threads needed?
I guess todays P3's should be better than the 8 year old SGI Personal Irises I have in my server farm at home, and they can handle hundreds of real time X Clients on my desktop machines.
I think it maybe just takes getting together a good standard (and 4dWM is a good'un) and coding this stuff.
Come on SGI - give us 4dWM for Linux!
Frog51
We thought it was weird, but it wouldn't run on most of my colleagues machines anyway - so I opened it using a text editor, and it's written in plain, unobfuscated text.
Lines like spread(email) are kinda obvious.
Still, the first guy who got it was distraught that she didn't love him after all:)
Umm - didn't Cray have terabyte+ RAM boxes masquerading as RAIDed disk? It's a speed thing. If you assume RAM is faster than disk (usually!) then running as much within RAM and not having to swap to/from disk is a GOOD THING (TM)
Just look in the page source - like any good slashdotter should:)
There is this trend to over-hype any news of IT mergers/buyouts etc especially when the word Linux comes up. Okay, this is probably going to get more readers with the current upswing in public favour for Open Source, but dramatising does nobody any favours.
I'm quite happy to believe CmdrTaco et al when they say they have a cast iron contract which ensures Slashdot's individuality. Yes, even companies after money can act ethically. Anyway, why alienate the very population they want as a market??
Frog51
VPN's are good - easy to access from anywhere, not just WLAN.
But if you go for one Access Point inside the firewall, it is easy to set up both ends - the AP has access control lists and both the AP and radio NIC have to have a radio ESS ID programmed. Devices will only talk to others on the same ESS network.
Then add the fact that the hop set and hop sequence (for frequency hopping) or the chipping code (for direct sequence) make for some fairly unique numbers it does tie things down pretty well.
11 Mb/sec ethernet bridges from Symbol and Telxon come in around £800 (or $800 in the states) and are basically plug'n'play (although you can configure the clever snmp gubbins if you want through telnet or html)
Afraid not! Symbol and Telxon have worked with some tweaking in some major food stores, but their abilities have to be limited and seamless roaming isn't exactly that.
Different countries hardware is NOT compatible. The US has "fry your brain" signal levels. Europe has 4 different frequency band standards (and France which is a law unto itself.) The base hardware works, but you need to replace the radio card in all cases!!!
Nope - if you go with direct sequence (eg aironet) you can't even see the signal above ambient rf noise. If you can see it you still need the chipping code (up to 63 bits) before you can reconstruct the signal and then you can run 3 levels of encryption over that (as default).
Hack that?? I think not! Why do you think the army developed it?
Seriously - go check out Empeg.
It is exactly what you need. Linux device the size of a car stereo with up to 490 minutes of mp3 songs. Blue display - has plugins like geiss for winamp - matches my Golf GTI turbo dashboard.
Smooth!!!
I use Symbol and Telxon/Aironet 802.11 radio systems every day because they definitely have the top performance on the market. My department has tested every name on the market and they came out on top. Access Points configurable through telnet.
Unfortunately they are only now porting drivers to Linux
I tend to use it a lot for Quake 2 sessions - one access point for 5 users within a couple of hundred feet and a wireless ethernet bridge across about 5 km to 2 users in another suburb.
No glitches! Runs sweet as sugar. The low overhead on an RF Lan means an 11Mbit link is generally 2 or 3 times faster than 10BaseT ethernet.
And the price...well, if we did without, we would have to pay for dialup - 7 x 10p per minute x hours and hours - and get a performance hit.
On another note, have you seen Symbol's new palm pilot with laser scanner and rf connectivity. It can run as a telnet, 5250, oracle or html client. Nice.
Well I consider myself a lifelong geek with 23 years pulling things to bits/tinkering/hacking etc and it took me days to get X to work on my laptop. It's fine on my desktop machines, 'cos they're all pretty standard, but my laptop is an annoying version of IBM's Thinkpad - and on that topic, Linux token-ring card drivers...flaky!!
I can't understand why people have a problem with "tampering with nature." Until we became farmers and altered our environment we were no better than all other animals. We have changed foods by breeding, and now when we can do it quickly through gene splicing people yell "Blasphemy!" The logical step is to alter ourselves and our offspring. We subconsciously alter our potential offspring anyway by picking a partner who fits our ideal - this puts a huge bias on possible gene patterns in the child.
If we can remove all genetically transmitted diseases then we should, obviously. I don't think all future parents will want "perfect" offspring though. Even if we get that level of control over genes we will still want individuality for them.
Okay, so it is kind of a stand in for evolution, but we've lost a lot of the benefits of Darwinian selection anyway with the high levels of medical skill keeping alive those who in a wilder world would have died.
I say create a million versions of humans so we can survive everywhere - underwater, Mars, Venus, in poisonous atmospheres - or else we get too close to extinction from 1 event.
Anyone want a copy of my genes??
I don't agree that it's 'cos of old software, as I use modern software (lots of NT, Irix, Linux etc etc) and still prefer the older real keyboards.
I do, however, agree that it is subjective - maybe there should be keyboard for each type of user...someone like me has no need for Caps Lock, Windows key, SysRq etc, but maybe some people do. I would like a bigger spacebar and left shift, the pipe character up top right where it should be and a whole host of other things - but that would also cause disturbance to those who like it like that.
So, manufacturers - how about more of you doing a pfuca
No way - there has never been a desktop more intuitive to use than Iris Desktop. GNOME and KDE are like kid's toys in comparison! I use everything from Windows - blerrk - and Linux to Solaris and Irix and nothing has the fully integrated and organised feel of Iris/4Dwm. Everything just does what you want - no faffing about with apps; it just works
Don't get me wrong, I am the biggest force pushing for Linux throughout my company and I love it - it will get there, but just not yet.